1//===- AsmPrinter.cpp - Common AsmPrinter code ----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the AsmPrinter class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/CodeGen/AsmPrinter.h"
14#include "CodeViewDebug.h"
15#include "DwarfDebug.h"
16#include "DwarfException.h"
17#include "PseudoProbePrinter.h"
18#include "WasmException.h"
19#include "WinCFGuard.h"
20#include "WinException.h"
21#include "llvm/ADT/APFloat.h"
22#include "llvm/ADT/APInt.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
25#include "llvm/ADT/SmallPtrSet.h"
26#include "llvm/ADT/SmallString.h"
27#include "llvm/ADT/SmallVector.h"
28#include "llvm/ADT/Statistic.h"
29#include "llvm/ADT/StringExtras.h"
30#include "llvm/ADT/StringRef.h"
31#include "llvm/ADT/TinyPtrVector.h"
32#include "llvm/ADT/Twine.h"
33#include "llvm/Analysis/ConstantFolding.h"
34#include "llvm/Analysis/MemoryLocation.h"
35#include "llvm/Analysis/OptimizationRemarkEmitter.h"
36#include "llvm/BinaryFormat/COFF.h"
37#include "llvm/BinaryFormat/Dwarf.h"
38#include "llvm/BinaryFormat/ELF.h"
39#include "llvm/CodeGen/AsmPrinterAnalysis.h"
40#include "llvm/CodeGen/BasicBlockSectionsProfileReader.h"
41#include "llvm/CodeGen/GCMetadata.h"
42#include "llvm/CodeGen/GCMetadataPrinter.h"
43#include "llvm/CodeGen/InsertCodePrefetch.h"
44#include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
45#include "llvm/CodeGen/MachineBasicBlock.h"
46#include "llvm/CodeGen/MachineBlockHashInfo.h"
47#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
48#include "llvm/CodeGen/MachineConstantPool.h"
49#include "llvm/CodeGen/MachineDominators.h"
50#include "llvm/CodeGen/MachineFrameInfo.h"
51#include "llvm/CodeGen/MachineFunction.h"
52#include "llvm/CodeGen/MachineFunctionPass.h"
53#include "llvm/CodeGen/MachineInstr.h"
54#include "llvm/CodeGen/MachineInstrBundle.h"
55#include "llvm/CodeGen/MachineJumpTableInfo.h"
56#include "llvm/CodeGen/MachineLoopInfo.h"
57#include "llvm/CodeGen/MachineModuleInfo.h"
58#include "llvm/CodeGen/MachineModuleInfoImpls.h"
59#include "llvm/CodeGen/MachineOperand.h"
60#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
61#include "llvm/CodeGen/StackMaps.h"
62#include "llvm/CodeGen/TargetFrameLowering.h"
63#include "llvm/CodeGen/TargetInstrInfo.h"
64#include "llvm/CodeGen/TargetLowering.h"
65#include "llvm/CodeGen/TargetOpcodes.h"
66#include "llvm/CodeGen/TargetRegisterInfo.h"
67#include "llvm/CodeGen/TargetSubtargetInfo.h"
68#include "llvm/Config/config.h"
69#include "llvm/IR/BasicBlock.h"
70#include "llvm/IR/Comdat.h"
71#include "llvm/IR/Constant.h"
72#include "llvm/IR/Constants.h"
73#include "llvm/IR/DataLayout.h"
74#include "llvm/IR/DebugInfoMetadata.h"
75#include "llvm/IR/DerivedTypes.h"
76#include "llvm/IR/EHPersonalities.h"
77#include "llvm/IR/Function.h"
78#include "llvm/IR/GCStrategy.h"
79#include "llvm/IR/GlobalAlias.h"
80#include "llvm/IR/GlobalIFunc.h"
81#include "llvm/IR/GlobalObject.h"
82#include "llvm/IR/GlobalValue.h"
83#include "llvm/IR/GlobalVariable.h"
84#include "llvm/IR/Instruction.h"
85#include "llvm/IR/Instructions.h"
86#include "llvm/IR/LLVMRemarkStreamer.h"
87#include "llvm/IR/Mangler.h"
88#include "llvm/IR/Metadata.h"
89#include "llvm/IR/Module.h"
90#include "llvm/IR/Operator.h"
91#include "llvm/IR/PseudoProbe.h"
92#include "llvm/IR/Type.h"
93#include "llvm/IR/Value.h"
94#include "llvm/IR/ValueHandle.h"
95#include "llvm/MC/MCAsmInfo.h"
96#include "llvm/MC/MCContext.h"
97#include "llvm/MC/MCDirectives.h"
98#include "llvm/MC/MCExpr.h"
99#include "llvm/MC/MCInst.h"
100#include "llvm/MC/MCSchedule.h"
101#include "llvm/MC/MCSection.h"
102#include "llvm/MC/MCSectionCOFF.h"
103#include "llvm/MC/MCSectionELF.h"
104#include "llvm/MC/MCSectionMachO.h"
105#include "llvm/MC/MCSectionXCOFF.h"
106#include "llvm/MC/MCStreamer.h"
107#include "llvm/MC/MCSubtargetInfo.h"
108#include "llvm/MC/MCSymbol.h"
109#include "llvm/MC/MCSymbolELF.h"
110#include "llvm/MC/MCTargetOptions.h"
111#include "llvm/MC/MCValue.h"
112#include "llvm/MC/SectionKind.h"
113#include "llvm/MC/TargetRegistry.h"
114#include "llvm/Object/ELFTypes.h"
115#include "llvm/Pass.h"
116#include "llvm/Remarks/RemarkStreamer.h"
117#include "llvm/Support/Casting.h"
118#include "llvm/Support/CommandLine.h"
119#include "llvm/Support/Compiler.h"
120#include "llvm/Support/ErrorHandling.h"
121#include "llvm/Support/FileSystem.h"
122#include "llvm/Support/Format.h"
123#include "llvm/Support/MathExtras.h"
124#include "llvm/Support/Path.h"
125#include "llvm/Support/VCSRevision.h"
126#include "llvm/Support/VirtualFileSystem.h"
127#include "llvm/Support/raw_ostream.h"
128#include "llvm/Target/TargetLoweringObjectFile.h"
129#include "llvm/Target/TargetMachine.h"
130#include "llvm/Target/TargetOptions.h"
131#include <algorithm>
132#include <cassert>
133#include <cinttypes>
134#include <cstdint>
135#include <iterator>
136#include <memory>
137#include <optional>
138#include <string>
139#include <utility>
140#include <vector>
141
142using namespace llvm;
143
144#define DEBUG_TYPE "asm-printer"
145
146// This is a replication of fields of object::PGOAnalysisMap::Features. It
147// should match the order of the fields so that
148// `object::PGOAnalysisMap::Features::decode(PgoAnalysisMapFeatures.getBits())`
149// succeeds.
150enum class PGOMapFeaturesEnum {
151 None,
152 FuncEntryCount,
153 BBFreq,
154 BrProb,
155 PropellerCFG,
156 All,
157};
158static cl::bits<PGOMapFeaturesEnum> PgoAnalysisMapFeatures(
159 "pgo-analysis-map", cl::Hidden, cl::CommaSeparated,
160 cl::values(
161 clEnumValN(PGOMapFeaturesEnum::None, "none", "Disable all options"),
162 clEnumValN(PGOMapFeaturesEnum::FuncEntryCount, "func-entry-count",
163 "Function Entry Count"),
164 clEnumValN(PGOMapFeaturesEnum::BBFreq, "bb-freq",
165 "Basic Block Frequency"),
166 clEnumValN(PGOMapFeaturesEnum::BrProb, "br-prob", "Branch Probability"),
167 clEnumValN(PGOMapFeaturesEnum::All, "all", "Enable all options")),
168 cl::desc(
169 "Enable extended information within the SHT_LLVM_BB_ADDR_MAP that is "
170 "extracted from PGO related analysis."));
171
172static cl::opt<bool> PgoAnalysisMapEmitBBSectionsCfg(
173 "pgo-analysis-map-emit-bb-sections-cfg",
174 cl::desc("Enable the post-link cfg information from the basic block "
175 "sections profile in the PGO analysis map"),
176 cl::Hidden, cl::init(Val: false));
177
178static cl::opt<bool> BBAddrMapSkipEmitBBEntries(
179 "basic-block-address-map-skip-bb-entries",
180 cl::desc("Skip emitting basic block entries in the SHT_LLVM_BB_ADDR_MAP "
181 "section. It's used to save binary size when BB entries are "
182 "unnecessary for some PGOAnalysisMap features."),
183 cl::Hidden, cl::init(Val: false));
184
185static cl::opt<bool> EmitJumpTableSizesSection(
186 "emit-jump-table-sizes-section",
187 cl::desc("Emit a section containing jump table addresses and sizes"),
188 cl::Hidden, cl::init(Val: false));
189
190// This isn't turned on by default, since several of the scheduling models are
191// not completely accurate, and we don't want to be misleading.
192static cl::opt<bool> PrintLatency(
193 "asm-print-latency",
194 cl::desc("Print instruction latencies as verbose asm comments"), cl::Hidden,
195 cl::init(Val: false));
196
197static cl::opt<std::string>
198 StackUsageFile("stack-usage-file",
199 cl::desc("Output filename for stack usage information"),
200 cl::value_desc("filename"), cl::Hidden);
201
202extern cl::opt<bool> EmitBBHash;
203
204STATISTIC(EmittedInsts, "Number of machine instrs printed");
205
206char AsmPrinter::ID = 0;
207
208namespace {
209class AddrLabelMapCallbackPtr final : CallbackVH {
210 AddrLabelMap *Map = nullptr;
211
212public:
213 AddrLabelMapCallbackPtr() = default;
214 AddrLabelMapCallbackPtr(Value *V) : CallbackVH(V) {}
215
216 void setPtr(BasicBlock *BB) {
217 ValueHandleBase::operator=(RHS: BB);
218 }
219
220 void setMap(AddrLabelMap *map) { Map = map; }
221
222 void deleted() override;
223 void allUsesReplacedWith(Value *V2) override;
224};
225} // namespace
226
227class llvm::AddrLabelMap {
228 MCContext &Context;
229 struct AddrLabelSymEntry {
230 /// The symbols for the label.
231 TinyPtrVector<MCSymbol *> Symbols;
232
233 Function *Fn; // The containing function of the BasicBlock.
234 unsigned Index; // The index in BBCallbacks for the BasicBlock.
235 };
236
237 DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
238
239 /// Callbacks for the BasicBlock's that we have entries for. We use this so
240 /// we get notified if a block is deleted or RAUWd.
241 std::vector<AddrLabelMapCallbackPtr> BBCallbacks;
242
243 /// This is a per-function list of symbols whose corresponding BasicBlock got
244 /// deleted. These symbols need to be emitted at some point in the file, so
245 /// AsmPrinter emits them after the function body.
246 DenseMap<AssertingVH<Function>, std::vector<MCSymbol *>>
247 DeletedAddrLabelsNeedingEmission;
248
249public:
250 AddrLabelMap(MCContext &context) : Context(context) {}
251
252 ~AddrLabelMap() {
253 assert(DeletedAddrLabelsNeedingEmission.empty() &&
254 "Some labels for deleted blocks never got emitted");
255 }
256
257 ArrayRef<MCSymbol *> getAddrLabelSymbolToEmit(BasicBlock *BB);
258
259 void takeDeletedSymbolsForFunction(Function *F,
260 std::vector<MCSymbol *> &Result);
261
262 void UpdateForDeletedBlock(BasicBlock *BB);
263 void UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New);
264};
265
266ArrayRef<MCSymbol *> AddrLabelMap::getAddrLabelSymbolToEmit(BasicBlock *BB) {
267 assert(BB->hasAddressTaken() &&
268 "Shouldn't get label for block without address taken");
269 AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
270
271 // If we already had an entry for this block, just return it.
272 if (!Entry.Symbols.empty()) {
273 assert(BB->getParent() == Entry.Fn && "Parent changed");
274 return Entry.Symbols;
275 }
276
277 // Otherwise, this is a new entry, create a new symbol for it and add an
278 // entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd.
279 BBCallbacks.emplace_back(args&: BB);
280 BBCallbacks.back().setMap(this);
281 Entry.Index = BBCallbacks.size() - 1;
282 Entry.Fn = BB->getParent();
283 MCSymbol *Sym = BB->hasAddressTaken() ? Context.createNamedTempSymbol()
284 : Context.createTempSymbol();
285 Entry.Symbols.push_back(NewVal: Sym);
286 return Entry.Symbols;
287}
288
289/// If we have any deleted symbols for F, return them.
290void AddrLabelMap::takeDeletedSymbolsForFunction(
291 Function *F, std::vector<MCSymbol *> &Result) {
292 DenseMap<AssertingVH<Function>, std::vector<MCSymbol *>>::iterator I =
293 DeletedAddrLabelsNeedingEmission.find(Val: F);
294
295 // If there are no entries for the function, just return.
296 if (I == DeletedAddrLabelsNeedingEmission.end())
297 return;
298
299 // Otherwise, take the list.
300 std::swap(x&: Result, y&: I->second);
301 DeletedAddrLabelsNeedingEmission.erase(I);
302}
303
304//===- Address of Block Management ----------------------------------------===//
305
306ArrayRef<MCSymbol *>
307AsmPrinter::getAddrLabelSymbolToEmit(const BasicBlock *BB) {
308 // Lazily create AddrLabelSymbols.
309 if (!AddrLabelSymbols)
310 AddrLabelSymbols = std::make_unique<AddrLabelMap>(args&: OutContext);
311 return AddrLabelSymbols->getAddrLabelSymbolToEmit(
312 BB: const_cast<BasicBlock *>(BB));
313}
314
315void AsmPrinter::takeDeletedSymbolsForFunction(
316 const Function *F, std::vector<MCSymbol *> &Result) {
317 // If no blocks have had their addresses taken, we're done.
318 if (!AddrLabelSymbols)
319 return;
320 return AddrLabelSymbols->takeDeletedSymbolsForFunction(
321 F: const_cast<Function *>(F), Result);
322}
323
324void AddrLabelMap::UpdateForDeletedBlock(BasicBlock *BB) {
325 // If the block got deleted, there is no need for the symbol. If the symbol
326 // was already emitted, we can just forget about it, otherwise we need to
327 // queue it up for later emission when the function is output.
328 AddrLabelSymEntry Entry = std::move(AddrLabelSymbols[BB]);
329 AddrLabelSymbols.erase(Val: BB);
330 assert(!Entry.Symbols.empty() && "Didn't have a symbol, why a callback?");
331 BBCallbacks[Entry.Index] = nullptr; // Clear the callback.
332
333#if !LLVM_MEMORY_SANITIZER_BUILD
334 // BasicBlock is destroyed already, so this access is UB detectable by msan.
335 assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) &&
336 "Block/parent mismatch");
337#endif
338
339 for (MCSymbol *Sym : Entry.Symbols) {
340 if (Sym->isDefined())
341 return;
342
343 // If the block is not yet defined, we need to emit it at the end of the
344 // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list
345 // for the containing Function. Since the block is being deleted, its
346 // parent may already be removed, we have to get the function from 'Entry'.
347 DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(x: Sym);
348 }
349}
350
351void AddrLabelMap::UpdateForRAUWBlock(BasicBlock *Old, BasicBlock *New) {
352 // Get the entry for the RAUW'd block and remove it from our map.
353 AddrLabelSymEntry OldEntry = std::move(AddrLabelSymbols[Old]);
354 AddrLabelSymbols.erase(Val: Old);
355 assert(!OldEntry.Symbols.empty() && "Didn't have a symbol, why a callback?");
356
357 AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New];
358
359 // If New is not address taken, just move our symbol over to it.
360 if (NewEntry.Symbols.empty()) {
361 BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback.
362 NewEntry = std::move(OldEntry); // Set New's entry.
363 return;
364 }
365
366 BBCallbacks[OldEntry.Index] = nullptr; // Update the callback.
367
368 // Otherwise, we need to add the old symbols to the new block's set.
369 llvm::append_range(C&: NewEntry.Symbols, R&: OldEntry.Symbols);
370}
371
372void AddrLabelMapCallbackPtr::deleted() {
373 Map->UpdateForDeletedBlock(BB: cast<BasicBlock>(Val: getValPtr()));
374}
375
376void AddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
377 Map->UpdateForRAUWBlock(Old: cast<BasicBlock>(Val: getValPtr()), New: cast<BasicBlock>(Val: V2));
378}
379
380/// getGVAlignment - Return the alignment to use for the specified global
381/// value. This rounds up to the preferred alignment if possible and legal.
382Align AsmPrinter::getGVAlignment(const GlobalObject *GV, const DataLayout &DL,
383 Align InAlign) {
384 Align Alignment;
385 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(Val: GV))
386 Alignment = DL.getPreferredAlign(GV: GVar);
387
388 // If InAlign is specified, round it to it.
389 if (InAlign > Alignment)
390 Alignment = InAlign;
391
392 // If the GV has a specified alignment, take it into account.
393 MaybeAlign GVAlign;
394 if (auto *GVar = dyn_cast<GlobalVariable>(Val: GV))
395 GVAlign = GVar->getAlign();
396 else if (auto *F = dyn_cast<Function>(Val: GV))
397 GVAlign = F->getAlign();
398 if (!GVAlign)
399 return Alignment;
400
401 assert(GVAlign && "GVAlign must be set");
402
403 // If the GVAlign is larger than NumBits, or if we are required to obey
404 // NumBits because the GV has an assigned section, obey it.
405 if (*GVAlign > Alignment || GV->hasSection())
406 Alignment = *GVAlign;
407 return Alignment;
408}
409
410AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer,
411 char &ID)
412 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
413 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
414 SM(*this) {
415 VerboseAsm = OutStreamer->isVerboseAsm();
416 DwarfUsesRelocationsAcrossSections =
417 MAI.doesDwarfUseRelocationsAcrossSections();
418 GetMMI = [this]() {
419 auto *MMIWP = getAnalysisIfAvailable<MachineModuleInfoWrapperPass>();
420 return MMIWP ? &MMIWP->getMMI() : nullptr;
421 };
422 GetORE = [this](MachineFunction &MF) {
423 return &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
424 };
425 GetMDT = [this](MachineFunction &MF) {
426 auto *MDTWrapper =
427 getAnalysisIfAvailable<MachineDominatorTreeWrapperPass>();
428 return MDTWrapper ? &MDTWrapper->getDomTree() : nullptr;
429 };
430 GetMLI = [this](MachineFunction &MF) {
431 auto *MLIWrapper = getAnalysisIfAvailable<MachineLoopInfoWrapperPass>();
432 return MLIWrapper ? &MLIWrapper->getLI() : nullptr;
433 };
434 BeginGCAssembly = [this](Module &M) {
435 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
436 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
437 for (const auto &I : *MI)
438 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(S&: *I))
439 MP->beginAssembly(M, Info&: *MI, AP&: *this);
440 };
441 FinishGCAssembly = [this](Module &M) {
442 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
443 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
444 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E;)
445 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(S&: **--I))
446 MP->finishAssembly(M, Info&: *MI, AP&: *this);
447 };
448 EmitStackMaps = [this](Module &M) {
449 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
450 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
451 bool NeedsDefault = false;
452 if (MI->begin() == MI->end())
453 // No GC strategy, use the default format.
454 NeedsDefault = true;
455 else
456 for (const auto &I : *MI) {
457 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(S&: *I))
458 if (MP->emitStackMaps(SM, AP&: *this))
459 continue;
460 // The strategy doesn't have printer or doesn't emit custom stack maps.
461 // Use the default format.
462 NeedsDefault = true;
463 }
464
465 if (NeedsDefault)
466 SM.serializeToStackMapSection();
467 };
468 AssertDebugEHFinalized = [&]() {
469 assert(!DD && Handlers.size() == NumUserHandlers &&
470 "Debug/EH info didn't get finalized");
471 };
472}
473
474AsmPrinter::~AsmPrinter() { AssertDebugEHFinalized(); }
475
476bool AsmPrinter::isPositionIndependent() const {
477 return TM.isPositionIndependent();
478}
479
480/// getFunctionNumber - Return a unique ID for the current function.
481unsigned AsmPrinter::getFunctionNumber() const {
482 return MF->getFunctionNumber();
483}
484
485const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
486 return *TM.getObjFileLowering();
487}
488
489const DataLayout &AsmPrinter::getDataLayout() const {
490 assert(MMI && "MMI could not be nullptr!");
491 return MMI->getModule()->getDataLayout();
492}
493
494// Do not use the cached DataLayout because some client use it without a Module
495// (dsymutil, llvm-dwarfdump).
496unsigned AsmPrinter::getPointerSize() const {
497 return TM.getPointerSize(AS: 0); // FIXME: Default address space
498}
499
500const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
501 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
502 return MF->getSubtarget<MCSubtargetInfo>();
503}
504
505void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
506 S.emitInstruction(Inst, STI: getSubtargetInfo());
507}
508
509/// getCurrentSection() - Return the current section we are emitting to.
510const MCSection *AsmPrinter::getCurrentSection() const {
511 return OutStreamer->getCurrentSectionOnly();
512}
513
514/// createDwarfDebug() - Create the DwarfDebug handler.
515DwarfDebug *AsmPrinter::createDwarfDebug() { return new DwarfDebug(this); }
516
517void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
518 AU.setPreservesAll();
519 MachineFunctionPass::getAnalysisUsage(AU);
520 AU.addRequired<MachineOptimizationRemarkEmitterPass>();
521 AU.addRequired<GCModuleInfo>();
522 AU.addRequired<LazyMachineBlockFrequencyInfoPass>();
523 AU.addRequired<MachineBranchProbabilityInfoWrapperPass>();
524 if (EmitBBHash)
525 AU.addRequired<MachineBlockHashInfo>();
526 AU.addUsedIfAvailable<BasicBlockSectionsProfileReaderWrapperPass>();
527}
528
529bool AsmPrinter::doInitialization(Module &M) {
530 MMI = GetMMI();
531 HasSplitStack = false;
532 HasNoSplitStack = false;
533 DbgInfoAvailable = !M.debug_compile_units().empty();
534 const Triple &Target = TM.getTargetTriple();
535
536 AddrLabelSymbols = nullptr;
537
538 // Initialize TargetLoweringObjectFile.
539 TM.getObjFileLowering()->Initialize(ctx&: OutContext, TM);
540
541 TM.getObjFileLowering()->getModuleMetadata(M);
542
543 // On AIX, we delay emitting any section information until
544 // after emitting the .file pseudo-op. This allows additional
545 // information (such as the embedded command line) to be associated
546 // with all sections in the object file rather than a single section.
547 if (!Target.isOSBinFormatXCOFF())
548 OutStreamer->initSections(STI: TM.getMCSubtargetInfo());
549
550 // Emit the version-min deployment target directive if needed.
551 //
552 // FIXME: If we end up with a collection of these sorts of Darwin-specific
553 // or ELF-specific things, it may make sense to have a platform helper class
554 // that will work with the target helper class. For now keep it here, as the
555 // alternative is duplicated code in each of the target asm printers that
556 // use the directive, where it would need the same conditionalization
557 // anyway.
558 if (Target.isOSBinFormatMachO() && Target.isOSDarwin()) {
559 Triple TVT(M.getDarwinTargetVariantTriple());
560 OutStreamer->emitVersionForTarget(
561 Target, SDKVersion: M.getSDKVersion(),
562 DarwinTargetVariantTriple: M.getDarwinTargetVariantTriple().empty() ? nullptr : &TVT,
563 DarwinTargetVariantSDKVersion: M.getDarwinTargetVariantSDKVersion());
564 }
565
566 // Allow the target to emit any magic that it wants at the start of the file.
567 emitStartOfAsmFile(M);
568
569 // Very minimal debug info. It is ignored if we emit actual debug info. If we
570 // don't, this at least helps the user find where a global came from.
571 if (MAI.hasSingleParameterDotFile()) {
572 // .file "foo.c"
573 if (MAI.isAIX()) {
574 const char VerStr[] =
575#ifdef PACKAGE_VENDOR
576 PACKAGE_VENDOR " "
577#endif
578 PACKAGE_NAME " version " PACKAGE_VERSION
579#ifdef LLVM_REVISION
580 " (" LLVM_REVISION ")"
581#endif
582 ;
583 // TODO: Add timestamp and description.
584 OutStreamer->emitFileDirective(Filename: M.getSourceFileName(), CompilerVersion: VerStr, TimeStamp: "", Description: "");
585 } else {
586 OutStreamer->emitFileDirective(
587 Filename: llvm::sys::path::filename(path: M.getSourceFileName()));
588 }
589 }
590
591 // On AIX, emit bytes for llvm.commandline metadata after .file so that the
592 // C_INFO symbol is preserved if any csect is kept by the linker.
593 if (Target.isOSBinFormatXCOFF()) {
594 emitModuleCommandLines(M);
595 // Now we can generate section information.
596 OutStreamer->switchSection(
597 Section: OutContext.getObjectFileInfo()->getTextSection());
598
599 // To work around an AIX assembler and/or linker bug, generate
600 // a rename for the default text-section symbol name. This call has
601 // no effect when generating object code directly.
602 MCSection *TextSection =
603 OutStreamer->getContext().getObjectFileInfo()->getTextSection();
604 MCSymbolXCOFF *XSym =
605 static_cast<MCSectionXCOFF *>(TextSection)->getQualNameSymbol();
606 if (XSym->hasRename())
607 OutStreamer->emitXCOFFRenameDirective(Name: XSym, Rename: XSym->getSymbolTableName());
608 }
609
610 BeginGCAssembly(M);
611
612 // Emit module-level inline asm if it exists.
613 if (M.hasModuleInlineAsm()) {
614 OutStreamer->AddComment(T: "Start of file scope inline assembly");
615 OutStreamer->addBlankLine();
616 for (const Module::GlobalAsmFragment &Frag : M.getModuleInlineAsm()) {
617 const MCSubtargetInfo &AsmSTI = TM.getMCSubtargetInfo(
618 CPU: Frag.Props.TargetCPU, FS: Frag.Props.TargetFeatures);
619 bool DidPush = emitTargetFeaturePush(STI: AsmSTI);
620 emitInlineAsm(
621 Str: Frag.Asm, STI: AsmSTI, MCOptions: TM.Options.MCOptions, LocMDNode: nullptr,
622 AsmDialect: InlineAsm::AsmDialect(TM.getMCAsmInfo().getAssemblerDialect()));
623 emitTargetFeaturePop(STI: AsmSTI, DidPush);
624 }
625 OutStreamer->AddComment(T: "End of file scope inline assembly");
626 OutStreamer->addBlankLine();
627 }
628
629 if (MAI.doesSupportDebugInformation()) {
630 bool EmitCodeView = M.getCodeViewFlag();
631 // On Windows targets, emit minimal CodeView compiler info even when debug
632 // info is disabled.
633 if ((Target.isOSWindows() || (Target.isUEFI() && EmitCodeView)) &&
634 M.getNamedMetadata(Name: "llvm.dbg.cu"))
635 Handlers.push_back(Elt: std::make_unique<CodeViewDebug>(args: this));
636 if (!EmitCodeView || M.getDwarfVersion()) {
637 if (hasDebugInfo()) {
638 DD = createDwarfDebug();
639 Handlers.push_back(Elt: std::unique_ptr<DwarfDebug>(DD));
640 }
641 }
642 }
643
644 if (M.getNamedMetadata(Name: PseudoProbeDescMetadataName))
645 PP = std::make_unique<PseudoProbeHandler>(args: this);
646
647 switch (MAI.getExceptionHandlingType()) {
648 case ExceptionHandling::None:
649 // We may want to emit CFI for debug.
650 [[fallthrough]];
651 case ExceptionHandling::SjLj:
652 case ExceptionHandling::DwarfCFI:
653 case ExceptionHandling::ARM:
654 for (auto &F : M.getFunctionList()) {
655 if (getFunctionCFISectionType(F) != CFISection::None)
656 ModuleCFISection = getFunctionCFISectionType(F);
657 // If any function needsUnwindTableEntry(), it needs .eh_frame and hence
658 // the module needs .eh_frame. If we have found that case, we are done.
659 if (ModuleCFISection == CFISection::EH)
660 break;
661 }
662 assert(MAI.getExceptionHandlingType() == ExceptionHandling::DwarfCFI ||
663 usesCFIWithoutEH() || ModuleCFISection != CFISection::EH);
664 break;
665 default:
666 break;
667 }
668
669 EHStreamer *ES = nullptr;
670 switch (MAI.getExceptionHandlingType()) {
671 case ExceptionHandling::None:
672 if (!usesCFIWithoutEH())
673 break;
674 [[fallthrough]];
675 case ExceptionHandling::SjLj:
676 case ExceptionHandling::DwarfCFI:
677 case ExceptionHandling::ZOS:
678 ES = new DwarfCFIException(this);
679 break;
680 case ExceptionHandling::ARM:
681 ES = new ARMException(this);
682 break;
683 case ExceptionHandling::WinEH:
684 switch (MAI.getWinEHEncodingType()) {
685 default: llvm_unreachable("unsupported unwinding information encoding");
686 case WinEH::EncodingType::Invalid:
687 break;
688 case WinEH::EncodingType::X86:
689 case WinEH::EncodingType::Itanium:
690 ES = new WinException(this);
691 break;
692 }
693 break;
694 case ExceptionHandling::Wasm:
695 ES = new WasmException(this);
696 break;
697 case ExceptionHandling::AIX:
698 ES = new AIXException(this);
699 break;
700 }
701 if (ES)
702 EHHandlers.push_back(Elt: std::unique_ptr<EHStreamer>(ES));
703
704 // All CFG modes required the tables emitted.
705 if (M.getControlFlowGuardMode() != ControlFlowGuardMode::Disabled)
706 Handlers.push_back(Elt: std::make_unique<WinCFGuard>(args: this));
707
708 for (auto &Handler : Handlers)
709 Handler->beginModule(M: &M);
710 for (auto &Handler : EHHandlers)
711 Handler->beginModule(M: &M);
712
713 return false;
714}
715
716static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
717 if (!MAI.hasWeakDefCanBeHiddenDirective())
718 return false;
719
720 return GV->canBeOmittedFromSymbolTable();
721}
722
723void AsmPrinter::emitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
724 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
725 switch (Linkage) {
726 case GlobalValue::CommonLinkage:
727 case GlobalValue::LinkOnceAnyLinkage:
728 case GlobalValue::LinkOnceODRLinkage:
729 case GlobalValue::WeakAnyLinkage:
730 case GlobalValue::WeakODRLinkage:
731 if (MAI.isMachO()) {
732 // .globl _foo
733 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_Global);
734
735 if (!canBeHidden(GV, MAI))
736 // .weak_definition _foo
737 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_WeakDefinition);
738 else
739 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_WeakDefAutoPrivate);
740 } else if (MAI.avoidWeakIfComdat() && GV->hasComdat()) {
741 // .globl _foo
742 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_Global);
743 //NOTE: linkonce is handled by the section the symbol was assigned to.
744 } else {
745 // .weak _foo
746 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_Weak);
747 }
748 return;
749 case GlobalValue::ExternalLinkage:
750 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_Global);
751 return;
752 case GlobalValue::PrivateLinkage:
753 case GlobalValue::InternalLinkage:
754 return;
755 case GlobalValue::ExternalWeakLinkage:
756 case GlobalValue::AvailableExternallyLinkage:
757 case GlobalValue::AppendingLinkage:
758 llvm_unreachable("Should never emit this");
759 }
760 llvm_unreachable("Unknown linkage type!");
761}
762
763void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
764 const GlobalValue *GV) const {
765 TM.getNameWithPrefix(Name, GV, Mang&: getObjFileLowering().getMangler());
766}
767
768MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
769 return TM.getSymbol(GV);
770}
771
772MCSymbol *AsmPrinter::getSymbolPreferLocal(const GlobalValue &GV) const {
773 // On ELF, use .Lfoo$local if GV is a non-interposable GlobalObject with an
774 // exact definion (intersection of GlobalValue::hasExactDefinition() and
775 // !isInterposable()). These linkages include: external, appending, internal,
776 // private. It may be profitable to use a local alias for external. The
777 // assembler would otherwise be conservative and assume a global default
778 // visibility symbol can be interposable, even if the code generator already
779 // assumed it.
780 if (TM.getTargetTriple().isOSBinFormatELF() && GV.canBenefitFromLocalAlias()) {
781 const Module &M = *GV.getParent();
782 if (TM.getRelocationModel() != Reloc::Static &&
783 M.getPIELevel() == PIELevel::Default && GV.isDSOLocal())
784 return getSymbolWithGlobalValueBase(GV: &GV, Suffix: "$local");
785 }
786 return TM.getSymbol(GV: &GV);
787}
788
789/// EmitGlobalVariable - Emit the specified global variable to the .s file.
790void AsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
791 bool IsEmuTLSVar = TM.useEmulatedTLS() && GV->isThreadLocal();
792 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
793 "No emulated TLS variables in the common section");
794
795 // Never emit TLS variable xyz in emulated TLS model.
796 // The initialization value is in __emutls_t.xyz instead of xyz.
797 if (IsEmuTLSVar)
798 return;
799
800 if (GV->hasInitializer()) {
801 // Check to see if this is a special global used by LLVM, if so, emit it.
802 if (emitSpecialLLVMGlobal(GV))
803 return;
804
805 // Skip the emission of global equivalents. The symbol can be emitted later
806 // on by emitGlobalGOTEquivs in case it turns out to be needed.
807 if (GlobalGOTEquivs.count(Key: getSymbol(GV)))
808 return;
809
810 if (isVerbose()) {
811 // When printing the control variable __emutls_v.*,
812 // we don't need to print the original TLS variable name.
813 GV->printAsOperand(O&: OutStreamer->getCommentOS(),
814 /*PrintType=*/false, M: GV->getParent());
815 OutStreamer->getCommentOS() << '\n';
816 }
817 }
818
819 MCSymbol *GVSym = getSymbol(GV);
820 MCSymbol *EmittedSym = GVSym;
821
822 // getOrCreateEmuTLSControlSym only creates the symbol with name and default
823 // attributes.
824 // GV's or GVSym's attributes will be used for the EmittedSym.
825 emitVisibility(Sym: EmittedSym, Visibility: GV->getVisibility(), IsDefinition: !GV->isDeclaration());
826
827 if (GV->isTagged()) {
828 Triple T = TM.getTargetTriple();
829
830 if (T.getArch() != Triple::aarch64)
831 OutContext.reportError(L: SMLoc(),
832 Msg: "tagged symbols (-fsanitize=memtag-globals) are "
833 "only supported on AArch64");
834 OutStreamer->emitSymbolAttribute(Symbol: EmittedSym, Attribute: MCSA_Memtag);
835 }
836
837 if (!GV->hasInitializer()) // External globals require no extra code.
838 return;
839
840 GVSym->redefineIfPossible();
841 if (GVSym->isDefined() || GVSym->isVariable())
842 OutContext.reportError(L: SMLoc(), Msg: "symbol '" + Twine(GVSym->getName()) +
843 "' is already defined");
844
845 if (MAI.hasDotTypeDotSizeDirective())
846 OutStreamer->emitSymbolAttribute(Symbol: EmittedSym, Attribute: MCSA_ELF_TypeObject);
847
848 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GO: GV, TM);
849
850 const DataLayout &DL = GV->getDataLayout();
851 uint64_t Size = GV->getGlobalSize(DL);
852
853 // If the alignment is specified, we *must* obey it. Overaligning a global
854 // with a specified alignment is a prompt way to break globals emitted to
855 // sections and expected to be contiguous (e.g. ObjC metadata).
856 const Align Alignment = getGVAlignment(GV, DL);
857
858 for (auto &Handler : Handlers)
859 Handler->setSymbolSize(Sym: GVSym, Size);
860
861 // Handle common symbols
862 if (GVKind.isCommon()) {
863 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
864 // .comm _foo, 42, 4
865 OutStreamer->emitCommonSymbol(Symbol: GVSym, Size, ByteAlignment: Alignment);
866 return;
867 }
868
869 // Determine to which section this global should be emitted.
870 MCSection *TheSection = getObjFileLowering().SectionForGlobal(GO: GV, Kind: GVKind, TM);
871
872 // If we have a bss global going to a section that supports the
873 // zerofill directive, do so here.
874 if (GVKind.isBSS() && MAI.isMachO() && TheSection->isBssSection()) {
875 if (Size == 0)
876 Size = 1; // zerofill of 0 bytes is undefined.
877 emitLinkage(GV, GVSym);
878 // .zerofill __DATA, __bss, _foo, 400, 5
879 OutStreamer->emitZerofill(Section: TheSection, Symbol: GVSym, Size, ByteAlignment: Alignment);
880 return;
881 }
882
883 // If this is a BSS local symbol and we are emitting in the BSS
884 // section use .lcomm/.comm directive.
885 if (GVKind.isBSSLocal() &&
886 getObjFileLowering().getBSSSection() == TheSection) {
887 if (Size == 0)
888 Size = 1; // .comm Foo, 0 is undefined, avoid it.
889
890 // Use .lcomm only if it supports user-specified alignment.
891 // Otherwise, while it would still be correct to use .lcomm in some
892 // cases (e.g. when Align == 1), the external assembler might enfore
893 // some -unknown- default alignment behavior, which could cause
894 // spurious differences between external and integrated assembler.
895 // Prefer to simply fall back to .local / .comm in this case.
896 if (MAI.getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
897 // .lcomm _foo, 42
898 OutStreamer->emitLocalCommonSymbol(Symbol: GVSym, Size, ByteAlignment: Alignment);
899 return;
900 }
901
902 // .local _foo
903 OutStreamer->emitSymbolAttribute(Symbol: GVSym, Attribute: MCSA_Local);
904 // .comm _foo, 42, 4
905 OutStreamer->emitCommonSymbol(Symbol: GVSym, Size, ByteAlignment: Alignment);
906 return;
907 }
908
909 // Handle thread local data for mach-o which requires us to output an
910 // additional structure of data and mangle the original symbol so that we
911 // can reference it later.
912 //
913 // TODO: This should become an "emit thread local global" method on TLOF.
914 // All of this macho specific stuff should be sunk down into TLOFMachO and
915 // stuff like "TLSExtraDataSection" should no longer be part of the parent
916 // TLOF class. This will also make it more obvious that stuff like
917 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
918 // specific code.
919 if (GVKind.isThreadLocal() && MAI.isMachO()) {
920 // Emit the .tbss symbol
921 MCSymbol *MangSym =
922 OutContext.getOrCreateSymbol(Name: GVSym->getName() + Twine("$tlv$init"));
923
924 if (GVKind.isThreadBSS()) {
925 TheSection = getObjFileLowering().getTLSBSSSection();
926 OutStreamer->emitTBSSSymbol(Section: TheSection, Symbol: MangSym, Size, ByteAlignment: Alignment);
927 } else if (GVKind.isThreadData()) {
928 OutStreamer->switchSection(Section: TheSection);
929
930 emitAlignment(Alignment, GV);
931 OutStreamer->emitLabel(Symbol: MangSym);
932
933 emitGlobalConstant(DL: GV->getDataLayout(),
934 CV: GV->getInitializer());
935 }
936
937 OutStreamer->addBlankLine();
938
939 // Emit the variable struct for the runtime.
940 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
941
942 OutStreamer->switchSection(Section: TLVSect);
943 // Emit the linkage here.
944 emitLinkage(GV, GVSym);
945 OutStreamer->emitLabel(Symbol: GVSym);
946
947 // Three pointers in size:
948 // - __tlv_bootstrap - used to make sure support exists
949 // - spare pointer, used when mapped by the runtime
950 // - pointer to mangled symbol above with initializer
951 unsigned PtrSize = DL.getPointerTypeSize(Ty: GV->getType());
952 OutStreamer->emitSymbolValue(Sym: GetExternalSymbolSymbol(Sym: "_tlv_bootstrap"),
953 Size: PtrSize);
954 OutStreamer->emitIntValue(Value: 0, Size: PtrSize);
955 OutStreamer->emitSymbolValue(Sym: MangSym, Size: PtrSize);
956
957 OutStreamer->addBlankLine();
958 return;
959 }
960
961 MCSymbol *EmittedInitSym = GVSym;
962
963 OutStreamer->switchSection(Section: TheSection);
964
965 emitLinkage(GV, GVSym: EmittedInitSym);
966 emitAlignment(Alignment, GV);
967
968 OutStreamer->emitLabel(Symbol: EmittedInitSym);
969 MCSymbol *LocalAlias = getSymbolPreferLocal(GV: *GV);
970 if (LocalAlias != EmittedInitSym)
971 OutStreamer->emitLabel(Symbol: LocalAlias);
972
973 emitGlobalConstant(DL: GV->getDataLayout(), CV: GV->getInitializer());
974
975 if (MAI.hasDotTypeDotSizeDirective())
976 // .size foo, 42
977 OutStreamer->emitELFSize(Symbol: EmittedInitSym,
978 Value: MCConstantExpr::create(Value: Size, Ctx&: OutContext));
979
980 OutStreamer->addBlankLine();
981}
982
983/// Emit the directive and value for debug thread local expression
984///
985/// \p Value - The value to emit.
986/// \p Size - The size of the integer (in bytes) to emit.
987void AsmPrinter::emitDebugValue(const MCExpr *Value, unsigned Size) const {
988 OutStreamer->emitValue(Value, Size);
989}
990
991void AsmPrinter::emitFunctionHeaderComment() {}
992
993void AsmPrinter::emitFunctionPrefix(ArrayRef<const Constant *> Prefix) {
994 const Function &F = MF->getFunction();
995 if (!MAI.hasSubsectionsViaSymbols()) {
996 for (auto &C : Prefix)
997 emitGlobalConstant(DL: F.getDataLayout(), CV: C);
998 return;
999 }
1000 // Preserving prefix-like data on platforms which use subsections-via-symbols
1001 // is a bit tricky. Here we introduce a symbol for the prefix-like data
1002 // and use the .alt_entry attribute to mark the function's real entry point
1003 // as an alternative entry point to the symbol that precedes the function..
1004 OutStreamer->emitLabel(Symbol: OutContext.createLinkerPrivateTempSymbol());
1005
1006 for (auto &C : Prefix) {
1007 emitGlobalConstant(DL: F.getDataLayout(), CV: C);
1008 }
1009
1010 // Emit an .alt_entry directive for the actual function symbol.
1011 OutStreamer->emitSymbolAttribute(Symbol: CurrentFnSym, Attribute: MCSA_AltEntry);
1012}
1013
1014/// EmitFunctionHeader - This method emits the header for the current
1015/// function.
1016void AsmPrinter::emitFunctionHeader() {
1017 const Function &F = MF->getFunction();
1018
1019 if (isVerbose())
1020 OutStreamer->getCommentOS()
1021 << "-- Begin function "
1022 << GlobalValue::dropLLVMManglingEscape(Name: F.getName()) << '\n';
1023
1024 // Print out constants referenced by the function
1025 emitConstantPool();
1026
1027 // Print the 'header' of function.
1028 // If basic block sections are desired, explicitly request a unique section
1029 // for this function's entry block.
1030 if (MF->front().isBeginSection())
1031 MF->setSection(getObjFileLowering().getUniqueSectionForFunction(F, TM));
1032 else
1033 MF->setSection(getObjFileLowering().SectionForGlobal(GO: &F, TM));
1034 OutStreamer->switchSection(Section: MF->getSection());
1035
1036 if (MAI.isAIX())
1037 emitLinkage(GV: &F, GVSym: CurrentFnDescSym);
1038 else
1039 emitVisibility(Sym: CurrentFnSym, Visibility: F.getVisibility());
1040
1041 emitLinkage(GV: &F, GVSym: CurrentFnSym);
1042 if (MAI.hasFunctionAlignment()) {
1043 Align PrefAlign = MF->getPreferredAlignment();
1044 if (MAI.useIntegratedAssembler() && MAI.hasPreferredAlignment()) {
1045 // Emit .p2align for the effective minimum alignment (which accounts for
1046 // F's own align attribute via getGVAlignment), then emit .prefalign only
1047 // when the preferred alignment is greater. The end symbol must be
1048 // created here, before the function body, so that .prefalign can
1049 // reference it; emitFunctionBody will emit the label at the function
1050 // end.
1051 Align MinAlign = emitAlignment(Alignment: MF->getAlignment(), GV: &F);
1052 if (MinAlign < PrefAlign) {
1053 CurrentFnEnd = createTempSymbol(Name: "func_end");
1054 OutStreamer->emitPrefAlign(A: PrefAlign, End: *CurrentFnEnd,
1055 /*EmitNops=*/true, /*Fill=*/0,
1056 STI: getSubtargetInfo());
1057 }
1058 } else {
1059 emitAlignment(Alignment: PrefAlign, GV: &F);
1060 }
1061 }
1062
1063 if (MAI.hasDotTypeDotSizeDirective())
1064 OutStreamer->emitSymbolAttribute(Symbol: CurrentFnSym, Attribute: MCSA_ELF_TypeFunction);
1065
1066 if (F.hasFnAttribute(Kind: Attribute::Cold))
1067 OutStreamer->emitSymbolAttribute(Symbol: CurrentFnSym, Attribute: MCSA_Cold);
1068
1069 // Emit the prefix data.
1070 if (F.hasPrefixData())
1071 emitFunctionPrefix(Prefix: {F.getPrefixData()});
1072
1073 // Emit KCFI type information before patchable-function-prefix nops.
1074 emitKCFITypeId(MF: *MF);
1075
1076 // Emit M NOPs for -fpatchable-function-entry=N,M where M>0. We arbitrarily
1077 // place prefix data before NOPs.
1078 unsigned PatchableFunctionPrefix =
1079 F.getFnAttributeAsParsedInteger(Kind: "patchable-function-prefix");
1080 unsigned PatchableFunctionEntry =
1081 F.getFnAttributeAsParsedInteger(Kind: "patchable-function-entry");
1082 if (PatchableFunctionPrefix) {
1083 CurrentPatchableFunctionEntrySym =
1084 OutContext.createLinkerPrivateTempSymbol();
1085 OutStreamer->emitLabel(Symbol: CurrentPatchableFunctionEntrySym);
1086 emitNops(N: PatchableFunctionPrefix);
1087 } else if (PatchableFunctionEntry) {
1088 // May be reassigned when emitting the body, to reference the label after
1089 // the initial BTI (AArch64) or endbr32/endbr64 (x86).
1090 CurrentPatchableFunctionEntrySym = CurrentFnBegin;
1091 }
1092
1093 // Emit the function prologue data for the indirect call sanitizer.
1094 if (const MDNode *MD = F.getMetadata(KindID: LLVMContext::MD_func_sanitize)) {
1095 assert(MD->getNumOperands() == 2);
1096
1097 auto *PrologueSig = mdconst::extract<Constant>(MD: MD->getOperand(I: 0));
1098 auto *TypeHash = mdconst::extract<Constant>(MD: MD->getOperand(I: 1));
1099 emitFunctionPrefix(Prefix: {PrologueSig, TypeHash});
1100 }
1101
1102 if (isVerbose()) {
1103 F.printAsOperand(O&: OutStreamer->getCommentOS(),
1104 /*PrintType=*/false, M: F.getParent());
1105 emitFunctionHeaderComment();
1106 OutStreamer->getCommentOS() << '\n';
1107 }
1108
1109 // Emit the function descriptor. This is a virtual function to allow targets
1110 // to emit their specific function descriptor. Right now it is only used by
1111 // the AIX target. The PowerPC 64-bit V1 ELF target also uses function
1112 // descriptors and should be converted to use this hook as well.
1113 if (MAI.isAIX())
1114 emitFunctionDescriptor();
1115
1116 // Emit the CurrentFnSym. This is a virtual function to allow targets to do
1117 // their wild and crazy things as required.
1118 emitFunctionEntryLabel();
1119
1120 // If the function had address-taken blocks that got deleted, then we have
1121 // references to the dangling symbols. Emit them at the start of the function
1122 // so that we don't get references to undefined symbols.
1123 std::vector<MCSymbol*> DeadBlockSyms;
1124 takeDeletedSymbolsForFunction(F: &F, Result&: DeadBlockSyms);
1125 for (MCSymbol *DeadBlockSym : DeadBlockSyms) {
1126 OutStreamer->AddComment(T: "Address taken block that was later removed");
1127 OutStreamer->emitLabel(Symbol: DeadBlockSym);
1128 }
1129
1130 if (CurrentFnBegin) {
1131 if (MAI.useAssignmentForEHBegin()) {
1132 MCSymbol *CurPos = OutContext.createTempSymbol();
1133 OutStreamer->emitLabel(Symbol: CurPos);
1134 OutStreamer->emitAssignment(Symbol: CurrentFnBegin,
1135 Value: MCSymbolRefExpr::create(Symbol: CurPos, Ctx&: OutContext));
1136 } else {
1137 OutStreamer->emitLabel(Symbol: CurrentFnBegin);
1138 }
1139 }
1140
1141 // Emit pre-function debug and/or EH information.
1142 for (auto &Handler : Handlers) {
1143 Handler->beginFunction(MF);
1144 Handler->beginBasicBlockSection(MBB: MF->front());
1145 }
1146 for (auto &Handler : EHHandlers) {
1147 Handler->beginFunction(MF);
1148 Handler->beginBasicBlockSection(MBB: MF->front());
1149 }
1150
1151 // Emit the prologue data.
1152 if (F.hasPrologueData())
1153 emitGlobalConstant(DL: F.getDataLayout(), CV: F.getPrologueData());
1154}
1155
1156/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
1157/// function. This can be overridden by targets as required to do custom stuff.
1158void AsmPrinter::emitFunctionEntryLabel() {
1159 CurrentFnSym->redefineIfPossible();
1160 OutStreamer->emitLabel(Symbol: CurrentFnSym);
1161
1162 if (TM.getTargetTriple().isOSBinFormatELF()) {
1163 MCSymbol *Sym = getSymbolPreferLocal(GV: MF->getFunction());
1164 if (Sym != CurrentFnSym) {
1165 CurrentFnBeginLocal = Sym;
1166 OutStreamer->emitLabel(Symbol: Sym);
1167 OutStreamer->emitSymbolAttribute(Symbol: Sym, Attribute: MCSA_ELF_TypeFunction);
1168 }
1169 }
1170}
1171
1172/// emitComments - Pretty-print comments for instructions.
1173static void emitComments(const MachineInstr &MI, const MCSubtargetInfo *STI,
1174 raw_ostream &CommentOS) {
1175 const MachineFunction *MF = MI.getMF();
1176 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
1177
1178 // Check for spills and reloads
1179
1180 // We assume a single instruction only has a spill or reload, not
1181 // both.
1182 std::optional<LocationSize> Size;
1183 if ((Size = MI.getRestoreSize(TII))) {
1184 CommentOS << Size->getValue() << "-byte Reload\n";
1185 } else if ((Size = MI.getFoldedRestoreSize(TII))) {
1186 if (!Size->hasValue())
1187 CommentOS << "Unknown-size Folded Reload\n";
1188 else if (Size->getValue())
1189 CommentOS << Size->getValue() << "-byte Folded Reload\n";
1190 } else if ((Size = MI.getSpillSize(TII))) {
1191 CommentOS << Size->getValue() << "-byte Spill\n";
1192 } else if ((Size = MI.getFoldedSpillSize(TII))) {
1193 if (!Size->hasValue())
1194 CommentOS << "Unknown-size Folded Spill\n";
1195 else if (Size->getValue())
1196 CommentOS << Size->getValue() << "-byte Folded Spill\n";
1197 }
1198
1199 // Check for spill-induced copies
1200 if (MI.getAsmPrinterFlag(Flag: MachineInstr::ReloadReuse))
1201 CommentOS << " Reload Reuse\n";
1202
1203 if (PrintLatency) {
1204 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
1205 const MCSchedModel &SCModel = STI->getSchedModel();
1206 int Latency = SCModel.computeInstrLatency<MCSubtargetInfo, MCInstrInfo,
1207 InstrItineraryData, MachineInstr>(
1208 STI: *STI, MCII: *TII, Inst: MI);
1209 // Report only interesting latencies.
1210 if (1 < Latency)
1211 CommentOS << " Latency: " << Latency << "\n";
1212 }
1213}
1214
1215/// emitImplicitDef - This method emits the specified machine instruction
1216/// that is an implicit def.
1217void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
1218 Register RegNo = MI->getOperand(i: 0).getReg();
1219
1220 SmallString<128> Str;
1221 raw_svector_ostream OS(Str);
1222 OS << "implicit-def: "
1223 << printReg(Reg: RegNo, TRI: MF->getSubtarget().getRegisterInfo());
1224
1225 OutStreamer->AddComment(T: OS.str());
1226 OutStreamer->addBlankLine();
1227}
1228
1229static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
1230 std::string Str;
1231 raw_string_ostream OS(Str);
1232 OS << "kill:";
1233 for (const MachineOperand &Op : MI->operands()) {
1234 assert(Op.isReg() && "KILL instruction must have only register operands");
1235 OS << ' ' << (Op.isDef() ? "def " : "killed ")
1236 << printReg(Reg: Op.getReg(), TRI: AP.MF->getSubtarget().getRegisterInfo());
1237 }
1238 AP.OutStreamer->AddComment(T: Str);
1239 AP.OutStreamer->addBlankLine();
1240}
1241
1242static void emitFakeUse(const MachineInstr *MI, AsmPrinter &AP) {
1243 std::string Str;
1244 raw_string_ostream OS(Str);
1245 OS << "fake_use:";
1246 for (const MachineOperand &Op : MI->operands()) {
1247 // In some circumstances we can end up with fake uses of constants; skip
1248 // these.
1249 if (!Op.isReg())
1250 continue;
1251 OS << ' ' << printReg(Reg: Op.getReg(), TRI: AP.MF->getSubtarget().getRegisterInfo());
1252 }
1253 AP.OutStreamer->AddComment(T: OS.str());
1254 AP.OutStreamer->addBlankLine();
1255}
1256
1257/// emitDebugValueComment - This method handles the target-independent form
1258/// of DBG_VALUE, returning true if it was able to do so. A false return
1259/// means the target will need to handle MI in EmitInstruction.
1260static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
1261 // This code handles only the 4-operand target-independent form.
1262 if (MI->isNonListDebugValue() && MI->getNumOperands() != 4)
1263 return false;
1264
1265 SmallString<128> Str;
1266 raw_svector_ostream OS(Str);
1267 OS << "DEBUG_VALUE: ";
1268
1269 const DILocalVariable *V = MI->getDebugVariable();
1270 if (auto *SP = dyn_cast<DISubprogram>(Val: V->getScope())) {
1271 StringRef Name = SP->getName();
1272 if (!Name.empty())
1273 OS << Name << ":";
1274 }
1275 OS << V->getName();
1276 OS << " <- ";
1277
1278 const DIExpression *Expr = MI->getDebugExpression();
1279 // First convert this to a non-variadic expression if possible, to simplify
1280 // the output.
1281 if (auto NonVariadicExpr = DIExpression::convertToNonVariadicExpression(Expr))
1282 Expr = *NonVariadicExpr;
1283 // Then, output the possibly-simplified expression.
1284 if (Expr->getNumElements()) {
1285 OS << '[';
1286 ListSeparator LS;
1287 for (auto &Op : Expr->expr_ops()) {
1288 OS << LS << dwarf::OperationEncodingString(Encoding: Op.getOp());
1289 for (unsigned I = 0; I < Op.getNumArgs(); ++I)
1290 OS << ' ' << Op.getArg(I);
1291 }
1292 OS << "] ";
1293 }
1294
1295 // Register or immediate value. Register 0 means undef.
1296 for (const MachineOperand &Op : MI->debug_operands()) {
1297 if (&Op != MI->debug_operands().begin())
1298 OS << ", ";
1299 switch (Op.getType()) {
1300 case MachineOperand::MO_FPImmediate: {
1301 APFloat APF = APFloat(Op.getFPImm()->getValueAPF());
1302 Type *ImmTy = Op.getFPImm()->getType();
1303 if (ImmTy->isBFloatTy() || ImmTy->isHalfTy() || ImmTy->isFloatTy() ||
1304 ImmTy->isDoubleTy()) {
1305 OS << APF.convertToDouble();
1306 } else {
1307 // There is no good way to print long double. Convert a copy to
1308 // double. Ah well, it's only a comment.
1309 bool ignored;
1310 APF.convert(ToSemantics: APFloat::IEEEdouble(), RM: APFloat::rmNearestTiesToEven,
1311 losesInfo: &ignored);
1312 OS << "(long double) " << APF.convertToDouble();
1313 }
1314 break;
1315 }
1316 case MachineOperand::MO_Immediate: {
1317 OS << Op.getImm();
1318 break;
1319 }
1320 case MachineOperand::MO_CImmediate: {
1321 Op.getCImm()->getValue().print(OS, isSigned: false /*isSigned*/);
1322 break;
1323 }
1324 case MachineOperand::MO_TargetIndex: {
1325 OS << "!target-index(" << Op.getIndex() << "," << Op.getOffset() << ")";
1326 break;
1327 }
1328 case MachineOperand::MO_Register:
1329 case MachineOperand::MO_FrameIndex: {
1330 Register Reg;
1331 std::optional<StackOffset> Offset;
1332 if (Op.isReg()) {
1333 Reg = Op.getReg();
1334 } else {
1335 const TargetFrameLowering *TFI =
1336 AP.MF->getSubtarget().getFrameLowering();
1337 Offset = TFI->getFrameIndexReference(MF: *AP.MF, FI: Op.getIndex(), FrameReg&: Reg);
1338 }
1339 if (!Reg) {
1340 // Suppress offset, it is not meaningful here.
1341 OS << "undef";
1342 break;
1343 }
1344 // The second operand is only an offset if it's an immediate.
1345 if (MI->isIndirectDebugValue())
1346 Offset = StackOffset::getFixed(Fixed: MI->getDebugOffset().getImm());
1347 if (Offset)
1348 OS << '[';
1349 OS << printReg(Reg, TRI: AP.MF->getSubtarget().getRegisterInfo());
1350 if (Offset)
1351 OS << '+' << Offset->getFixed() << ']';
1352 break;
1353 }
1354 default:
1355 llvm_unreachable("Unknown operand type");
1356 }
1357 }
1358
1359 // NOTE: Want this comment at start of line, don't emit with AddComment.
1360 AP.OutStreamer->emitRawComment(T: Str);
1361 return true;
1362}
1363
1364/// This method handles the target-independent form of DBG_LABEL, returning
1365/// true if it was able to do so. A false return means the target will need
1366/// to handle MI in EmitInstruction.
1367static bool emitDebugLabelComment(const MachineInstr *MI, AsmPrinter &AP) {
1368 if (MI->getNumOperands() != 1)
1369 return false;
1370
1371 SmallString<128> Str;
1372 raw_svector_ostream OS(Str);
1373 OS << "DEBUG_LABEL: ";
1374
1375 const DILabel *V = MI->getDebugLabel();
1376 if (auto *SP = dyn_cast<DISubprogram>(
1377 Val: V->getScope()->getNonLexicalBlockFileScope())) {
1378 StringRef Name = SP->getName();
1379 if (!Name.empty())
1380 OS << Name << ":";
1381 }
1382 OS << V->getName();
1383
1384 // NOTE: Want this comment at start of line, don't emit with AddComment.
1385 AP.OutStreamer->emitRawComment(T: OS.str());
1386 return true;
1387}
1388
1389AsmPrinter::CFISection
1390AsmPrinter::getFunctionCFISectionType(const Function &F) const {
1391 // Ignore functions that won't get emitted.
1392 if (F.isDeclarationForLinker())
1393 return CFISection::None;
1394
1395 if (MAI.getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
1396 F.needsUnwindTableEntry())
1397 return CFISection::EH;
1398
1399 if (MAI.usesCFIWithoutEH() && F.hasUWTable())
1400 return CFISection::EH;
1401
1402 if (hasDebugInfo() || TM.Options.ForceDwarfFrameSection)
1403 return CFISection::Debug;
1404
1405 return CFISection::None;
1406}
1407
1408AsmPrinter::CFISection
1409AsmPrinter::getFunctionCFISectionType(const MachineFunction &MF) const {
1410 return getFunctionCFISectionType(F: MF.getFunction());
1411}
1412
1413bool AsmPrinter::needsSEHMoves() {
1414 return MAI.usesWindowsCFI() && MF->getFunction().needsUnwindTableEntry();
1415}
1416
1417bool AsmPrinter::usesCFIWithoutEH() const {
1418 return MAI.usesCFIWithoutEH() && ModuleCFISection != CFISection::None;
1419}
1420
1421void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
1422 ExceptionHandling ExceptionHandlingType = MAI.getExceptionHandlingType();
1423 if (!usesCFIWithoutEH() &&
1424 ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
1425 ExceptionHandlingType != ExceptionHandling::ARM)
1426 return;
1427
1428 if (getFunctionCFISectionType(MF: *MF) == CFISection::None)
1429 return;
1430
1431 // If there is no "real" instruction following this CFI instruction, skip
1432 // emitting it; it would be beyond the end of the function's FDE range.
1433 auto *MBB = MI.getParent();
1434 auto I = std::next(x: MI.getIterator());
1435 while (I != MBB->end() && I->isTransient())
1436 ++I;
1437 if (I == MBB->instr_end() &&
1438 MBB->getReverseIterator() == MBB->getParent()->rbegin())
1439 return;
1440
1441 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
1442 unsigned CFIIndex = MI.getOperand(i: 0).getCFIIndex();
1443 const MCCFIInstruction &CFI = Instrs[CFIIndex];
1444 emitCFIInstruction(Inst: CFI);
1445}
1446
1447void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
1448 // The operands are the MCSymbol and the frame offset of the allocation.
1449 MCSymbol *FrameAllocSym = MI.getOperand(i: 0).getMCSymbol();
1450 int FrameOffset = MI.getOperand(i: 1).getImm();
1451
1452 // Emit a symbol assignment.
1453 OutStreamer->emitAssignment(Symbol: FrameAllocSym,
1454 Value: MCConstantExpr::create(Value: FrameOffset, Ctx&: OutContext));
1455}
1456
1457/// Returns the BB metadata to be emitted in the SHT_LLVM_BB_ADDR_MAP section
1458/// for a given basic block. This can be used to capture more precise profile
1459/// information.
1460static uint32_t getBBAddrMapMetadata(const MachineBasicBlock &MBB) {
1461 const TargetInstrInfo *TII = MBB.getParent()->getSubtarget().getInstrInfo();
1462 return object::BBAddrMap::BBEntry::Metadata{
1463 .HasReturn: MBB.isReturnBlock(), .HasTailCall: !MBB.empty() && TII->isTailCall(Inst: MBB.back()),
1464 .IsEHPad: MBB.isEHPad(), .CanFallThrough: const_cast<MachineBasicBlock &>(MBB).canFallThrough(),
1465 .HasIndirectBranch: !MBB.empty() && MBB.rbegin()->isIndirectBranch()}
1466 .encode();
1467}
1468
1469static llvm::object::BBAddrMap::Features
1470getBBAddrMapFeature(const MachineFunction &MF, int NumMBBSectionRanges,
1471 bool HasCalls, const CFGProfile *FuncCFGProfile) {
1472 // Ensure that the user has not passed in additional options while also
1473 // specifying all or none.
1474 if ((PgoAnalysisMapFeatures.isSet(V: PGOMapFeaturesEnum::None) ||
1475 PgoAnalysisMapFeatures.isSet(V: PGOMapFeaturesEnum::All)) &&
1476 popcount(Value: PgoAnalysisMapFeatures.getBits()) != 1) {
1477 MF.getFunction().getContext().emitError(
1478 ErrorStr: "-pgo-analysis-map can accept only all or none with no additional "
1479 "values.");
1480 }
1481
1482 bool NoFeatures = PgoAnalysisMapFeatures.isSet(V: PGOMapFeaturesEnum::None);
1483 bool AllFeatures = PgoAnalysisMapFeatures.isSet(V: PGOMapFeaturesEnum::All);
1484 bool FuncEntryCountEnabled =
1485 AllFeatures || (!NoFeatures && PgoAnalysisMapFeatures.isSet(
1486 V: PGOMapFeaturesEnum::FuncEntryCount));
1487 bool BBFreqEnabled =
1488 AllFeatures ||
1489 (!NoFeatures && PgoAnalysisMapFeatures.isSet(V: PGOMapFeaturesEnum::BBFreq));
1490 bool BrProbEnabled =
1491 AllFeatures ||
1492 (!NoFeatures && PgoAnalysisMapFeatures.isSet(V: PGOMapFeaturesEnum::BrProb));
1493 bool PostLinkCfgEnabled = FuncCFGProfile && PgoAnalysisMapEmitBBSectionsCfg;
1494
1495 if ((BBFreqEnabled || BrProbEnabled) && BBAddrMapSkipEmitBBEntries) {
1496 MF.getFunction().getContext().emitError(
1497 ErrorStr: "BB entries info is required for BBFreq and BrProb features");
1498 }
1499 return {.FuncEntryCount: FuncEntryCountEnabled, .BBFreq: BBFreqEnabled, .BrProb: BrProbEnabled,
1500 .MultiBBRange: MF.hasBBSections() && NumMBBSectionRanges > 1,
1501 // Use static_cast to avoid breakage of tests on windows.
1502 .OmitBBEntries: static_cast<bool>(BBAddrMapSkipEmitBBEntries), .CallsiteEndOffsets: HasCalls,
1503 .BBHash: static_cast<bool>(EmitBBHash), .PostLinkCfg: PostLinkCfgEnabled};
1504}
1505
1506void AsmPrinter::emitBBAddrMapSection(const MachineFunction &MF) {
1507 MCSection *BBAddrMapSection =
1508 getObjFileLowering().getBBAddrMapSection(TextSec: *MF.getSection());
1509 assert(BBAddrMapSection && ".llvm_bb_addr_map section is not initialized.");
1510 bool HasCalls = !CurrentFnCallsiteEndSymbols.empty();
1511
1512 const BasicBlockSectionsProfileReader *BBSPR = nullptr;
1513 if (auto *BBSPRPass =
1514 getAnalysisIfAvailable<BasicBlockSectionsProfileReaderWrapperPass>())
1515 BBSPR = &BBSPRPass->getBBSPR();
1516 const CFGProfile *FuncCFGProfile = nullptr;
1517 if (BBSPR)
1518 FuncCFGProfile = BBSPR->getFunctionCFGProfile(FuncName: MF.getFunction().getName());
1519
1520 const MCSymbol *FunctionSymbol = getFunctionBegin();
1521
1522 OutStreamer->pushSection();
1523 OutStreamer->switchSection(Section: BBAddrMapSection);
1524 OutStreamer->AddComment(T: "version");
1525 uint8_t BBAddrMapVersion = OutStreamer->getContext().getBBAddrMapVersion();
1526 OutStreamer->emitInt8(Value: BBAddrMapVersion);
1527 OutStreamer->AddComment(T: "feature");
1528 auto Features = getBBAddrMapFeature(MF, NumMBBSectionRanges: MBBSectionRanges.size(), HasCalls,
1529 FuncCFGProfile);
1530 OutStreamer->emitInt16(Value: Features.encode());
1531 // Emit BB Information for each basic block in the function.
1532 if (Features.MultiBBRange) {
1533 OutStreamer->AddComment(T: "number of basic block ranges");
1534 OutStreamer->emitULEB128IntValue(Value: MBBSectionRanges.size());
1535 }
1536 // Number of blocks in each MBB section.
1537 MapVector<MBBSectionID, unsigned> MBBSectionNumBlocks;
1538 const MCSymbol *PrevMBBEndSymbol = nullptr;
1539 if (!Features.MultiBBRange) {
1540 OutStreamer->AddComment(T: "function address");
1541 OutStreamer->emitSymbolValue(Sym: FunctionSymbol, Size: getPointerSize());
1542 OutStreamer->AddComment(T: "number of basic blocks");
1543 OutStreamer->emitULEB128IntValue(Value: MF.size());
1544 PrevMBBEndSymbol = FunctionSymbol;
1545 } else {
1546 unsigned BBCount = 0;
1547 for (const MachineBasicBlock &MBB : MF) {
1548 BBCount++;
1549 if (MBB.isEndSection()) {
1550 // Store each section's basic block count when it ends.
1551 MBBSectionNumBlocks[MBB.getSectionID()] = BBCount;
1552 // Reset the count for the next section.
1553 BBCount = 0;
1554 }
1555 }
1556 }
1557 // Emit the BB entry for each basic block in the function.
1558 for (const MachineBasicBlock &MBB : MF) {
1559 const MCSymbol *MBBSymbol =
1560 MBB.isEntryBlock() ? FunctionSymbol : MBB.getSymbol();
1561 bool IsBeginSection =
1562 Features.MultiBBRange && (MBB.isBeginSection() || MBB.isEntryBlock());
1563 if (IsBeginSection) {
1564 OutStreamer->AddComment(T: "base address");
1565 OutStreamer->emitSymbolValue(Sym: MBBSymbol, Size: getPointerSize());
1566 OutStreamer->AddComment(T: "number of basic blocks");
1567 OutStreamer->emitULEB128IntValue(Value: MBBSectionNumBlocks[MBB.getSectionID()]);
1568 PrevMBBEndSymbol = MBBSymbol;
1569 }
1570
1571 auto MBHI =
1572 Features.BBHash ? &getAnalysis<MachineBlockHashInfo>() : nullptr;
1573
1574 if (!Features.OmitBBEntries) {
1575 OutStreamer->AddComment(T: "BB id");
1576 // Emit the BB ID for this basic block.
1577 // We only emit BaseID since CloneID is unset for
1578 // -basic-block-adress-map.
1579 // TODO: Emit the full BBID when labels and sections can be mixed
1580 // together.
1581 OutStreamer->emitULEB128IntValue(Value: MBB.getBBID()->BaseID);
1582 // Emit the basic block offset relative to the end of the previous block.
1583 // This is zero unless the block is padded due to alignment.
1584 emitLabelDifferenceAsULEB128(Hi: MBBSymbol, Lo: PrevMBBEndSymbol);
1585 const MCSymbol *CurrentLabel = MBBSymbol;
1586 if (HasCalls) {
1587 auto CallsiteEndSymbols = CurrentFnCallsiteEndSymbols.lookup(Val: &MBB);
1588 OutStreamer->AddComment(T: "number of callsites");
1589 OutStreamer->emitULEB128IntValue(Value: CallsiteEndSymbols.size());
1590 for (const MCSymbol *CallsiteEndSymbol : CallsiteEndSymbols) {
1591 // Emit the callsite offset.
1592 emitLabelDifferenceAsULEB128(Hi: CallsiteEndSymbol, Lo: CurrentLabel);
1593 CurrentLabel = CallsiteEndSymbol;
1594 }
1595 }
1596 // Emit the offset to the end of the block, which can be used to compute
1597 // the total block size.
1598 emitLabelDifferenceAsULEB128(Hi: MBB.getEndSymbol(), Lo: CurrentLabel);
1599 // Emit the Metadata.
1600 OutStreamer->emitULEB128IntValue(Value: getBBAddrMapMetadata(MBB));
1601 // Emit the Hash.
1602 if (MBHI) {
1603 OutStreamer->emitInt64(Value: MBHI->getMBBHash(MBB));
1604 }
1605 }
1606 PrevMBBEndSymbol = MBB.getEndSymbol();
1607 }
1608
1609 if (Features.hasPGOAnalysis()) {
1610 assert(BBAddrMapVersion >= 2 &&
1611 "PGOAnalysisMap only supports version 2 or later");
1612
1613 if (Features.FuncEntryCount) {
1614 OutStreamer->AddComment(T: "function entry count");
1615 auto MaybeEntryCount = MF.getFunction().getEntryCount();
1616 OutStreamer->emitULEB128IntValue(Value: MaybeEntryCount ? *MaybeEntryCount : 0);
1617 }
1618 const MachineBlockFrequencyInfo *MBFI =
1619 Features.BBFreq
1620 ? &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI()
1621 : nullptr;
1622 const MachineBranchProbabilityInfo *MBPI =
1623 Features.BrProb
1624 ? &getAnalysis<MachineBranchProbabilityInfoWrapperPass>().getMBPI()
1625 : nullptr;
1626
1627 if (Features.BBFreq || Features.BrProb) {
1628 for (const MachineBasicBlock &MBB : MF) {
1629 if (Features.BBFreq) {
1630 OutStreamer->AddComment(T: "basic block frequency");
1631 OutStreamer->emitULEB128IntValue(
1632 Value: MBFI->getBlockFreq(MBB: &MBB).getFrequency());
1633 if (Features.PostLinkCfg) {
1634 OutStreamer->AddComment(T: "basic block frequency (propeller)");
1635 OutStreamer->emitULEB128IntValue(
1636 Value: FuncCFGProfile->getBlockCount(BBID: *MBB.getBBID()));
1637 }
1638 }
1639 if (Features.BrProb) {
1640 unsigned SuccCount = MBB.succ_size();
1641 OutStreamer->AddComment(T: "basic block successor count");
1642 OutStreamer->emitULEB128IntValue(Value: SuccCount);
1643 for (const MachineBasicBlock *SuccMBB : MBB.successors()) {
1644 OutStreamer->AddComment(T: "successor BB ID");
1645 OutStreamer->emitULEB128IntValue(Value: SuccMBB->getBBID()->BaseID);
1646 OutStreamer->AddComment(T: "successor branch probability");
1647 OutStreamer->emitULEB128IntValue(
1648 Value: MBPI->getEdgeProbability(Src: &MBB, Dst: SuccMBB).getNumerator());
1649 if (Features.PostLinkCfg) {
1650 OutStreamer->AddComment(T: "successor branch frequency (propeller)");
1651 OutStreamer->emitULEB128IntValue(Value: FuncCFGProfile->getEdgeCount(
1652 SrcBBID: *MBB.getBBID(), SinkBBID: *SuccMBB->getBBID()));
1653 }
1654 }
1655 }
1656 }
1657 }
1658 }
1659
1660 OutStreamer->popSection();
1661}
1662
1663void AsmPrinter::emitKCFITrapEntry(const MachineFunction &MF,
1664 const MCSymbol *Symbol) {
1665 MCSection *Section =
1666 getObjFileLowering().getKCFITrapSection(TextSec: *MF.getSection());
1667 if (!Section)
1668 return;
1669
1670 OutStreamer->pushSection();
1671 OutStreamer->switchSection(Section);
1672
1673 MCSymbol *Loc = OutContext.createLinkerPrivateTempSymbol();
1674 OutStreamer->emitLabel(Symbol: Loc);
1675 OutStreamer->emitAbsoluteSymbolDiff(Hi: Symbol, Lo: Loc, Size: 4);
1676
1677 OutStreamer->popSection();
1678}
1679
1680void AsmPrinter::emitKCFITypeId(const MachineFunction &MF) {
1681 const Function &F = MF.getFunction();
1682 if (const MDNode *MD = F.getMetadata(KindID: LLVMContext::MD_kcfi_type))
1683 emitGlobalConstant(DL: F.getDataLayout(),
1684 CV: mdconst::extract<ConstantInt>(MD: MD->getOperand(I: 0)));
1685}
1686
1687void AsmPrinter::emitPseudoProbe(const MachineInstr &MI) {
1688 if (PP) {
1689 auto GUID = MI.getOperand(i: 0).getImm();
1690 auto Index = MI.getOperand(i: 1).getImm();
1691 auto Type = MI.getOperand(i: 2).getImm();
1692 auto Attr = MI.getOperand(i: 3).getImm();
1693 DILocation *DebugLoc = MI.getDebugLoc();
1694 PP->emitPseudoProbe(Guid: GUID, Index, Type, Attr, DebugLoc);
1695 }
1696}
1697
1698void AsmPrinter::emitStackSizeSection(const MachineFunction &MF) {
1699 if (!MF.getTarget().Options.EmitStackSizeSection)
1700 return;
1701
1702 MCSection *StackSizeSection =
1703 getObjFileLowering().getStackSizesSection(TextSec: *MF.getSection());
1704 if (!StackSizeSection)
1705 return;
1706
1707 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1708 // Don't emit functions with dynamic stack allocations.
1709 if (FrameInfo.hasVarSizedObjects())
1710 return;
1711
1712 OutStreamer->pushSection();
1713 OutStreamer->switchSection(Section: StackSizeSection);
1714
1715 const MCSymbol *FunctionSymbol = getFunctionBegin();
1716 uint64_t StackSize =
1717 FrameInfo.getStackSize() + FrameInfo.getUnsafeStackSize();
1718 OutStreamer->emitSymbolValue(Sym: FunctionSymbol, Size: TM.getProgramPointerSize());
1719 OutStreamer->emitULEB128IntValue(Value: StackSize);
1720
1721 OutStreamer->popSection();
1722}
1723
1724void AsmPrinter::emitStackUsage(const MachineFunction &MF) {
1725 const std::string OutputFilename =
1726 !StackUsageFile.empty() ? StackUsageFile
1727 : MF.getTarget().Options.StackUsageFile;
1728
1729 // OutputFilename empty implies -fstack-usage is not passed.
1730 if (OutputFilename.empty())
1731 return;
1732
1733 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1734 uint64_t StackSize =
1735 FrameInfo.getStackSize() + FrameInfo.getUnsafeStackSize();
1736
1737 if (StackUsageStream == nullptr) {
1738 std::error_code EC;
1739 StackUsageStream =
1740 std::make_unique<raw_fd_ostream>(args: OutputFilename, args&: EC, args: sys::fs::OF_Text);
1741 if (EC) {
1742 errs() << "Could not open file: " << EC.message();
1743 return;
1744 }
1745 }
1746
1747 if (const DISubprogram *DSP = MF.getFunction().getSubprogram())
1748 *StackUsageStream << DSP->getFilename() << ':' << DSP->getLine();
1749 else
1750 *StackUsageStream << MF.getFunction().getParent()->getName();
1751
1752 *StackUsageStream << ':' << MF.getName() << '\t' << StackSize << '\t';
1753 if (FrameInfo.hasVarSizedObjects())
1754 *StackUsageStream << "dynamic\n";
1755 else
1756 *StackUsageStream << "static\n";
1757}
1758
1759/// Extracts a numeric type identifier of a Function's type from
1760/// callgraph metadata. Returns null if metadata cannot be found.
1761static ConstantInt *extractNumericCGTypeId(const Function &F) {
1762 SmallVector<MDNode *, 2> Types;
1763 F.getMetadata(KindID: LLVMContext::MD_callgraph, MDs&: Types);
1764 for (const auto &Type : Types) {
1765 if (Type->getNumOperands() == 1 && isa<MDString>(Val: Type->getOperand(I: 0))) {
1766 MDString *MDTypeId = cast<MDString>(Val: Type->getOperand(I: 0));
1767 uint64_t TypeIdVal = llvm::MD5Hash(Str: MDTypeId->getString());
1768 IntegerType *Int64Ty = Type::getInt64Ty(C&: F.getContext());
1769 return ConstantInt::get(Ty: Int64Ty, V: TypeIdVal);
1770 }
1771 }
1772 return nullptr;
1773}
1774
1775/// Emits .llvm.callgraph section.
1776void AsmPrinter::emitCallGraphSection(const MachineFunction &MF,
1777 FunctionCallGraphInfo &FuncCGInfo) {
1778 if (!MF.getTarget().Options.EmitCallGraphSection)
1779 return;
1780
1781 // Switch to the call graph section for the function
1782 MCSection *FuncCGSection =
1783 getObjFileLowering().getCallGraphSection(TextSec: *getCurrentSection());
1784 assert(FuncCGSection && "null callgraph section");
1785 OutStreamer->pushSection();
1786 OutStreamer->switchSection(Section: FuncCGSection);
1787
1788 const Function &F = MF.getFunction();
1789 // If this function has external linkage or has its address taken and
1790 // it is not a callback, then anything could call it.
1791 bool IsIndirectTarget =
1792 !F.hasLocalLinkage() || F.hasAddressTaken(nullptr,
1793 /*IgnoreCallbackUses=*/true,
1794 /*IgnoreAssumeLikeCalls=*/true,
1795 /*IgnoreLLVMUsed=*/IngoreLLVMUsed: false);
1796
1797 const auto &DirectCallees = FuncCGInfo.DirectCallees;
1798 const auto &IndirectCalleeTypeIDs = FuncCGInfo.IndirectCalleeTypeIDs;
1799
1800 using namespace callgraph;
1801 Flags CGFlags = Flags::None;
1802 if (IsIndirectTarget)
1803 CGFlags |= Flags::IsIndirectTarget;
1804 if (DirectCallees.size() > 0)
1805 CGFlags |= Flags::HasDirectCallees;
1806 if (IndirectCalleeTypeIDs.size() > 0)
1807 CGFlags |= Flags::HasIndirectCallees;
1808
1809 // Emit function's call graph information.
1810 // 1) CallGraphSectionFormatVersion
1811 // 2) Flags
1812 // a. LSB bit 0 is set to 1 if the function is a potential indirect
1813 // target.
1814 // b. LSB bit 1 is set to 1 if there are direct callees.
1815 // c. LSB bit 2 is set to 1 if there are indirect callees.
1816 // d. Rest of the 5 bits in Flags are reserved for any future use.
1817 // 3) Function entry PC.
1818 // 4) FunctionTypeID if the function is indirect target and its type id
1819 // is known, otherwise it is set to 0.
1820 // 5) Number of unique direct callees, if at least one exists.
1821 // 6) For each unique direct callee, the callee's PC.
1822 // 7) Number of unique indirect target type IDs, if at least one exists.
1823 // 8) Each unique indirect target type id.
1824 OutStreamer->emitInt8(Value: CallGraphSectionFormatVersion::V_0);
1825 OutStreamer->emitInt8(Value: static_cast<uint8_t>(CGFlags));
1826 OutStreamer->emitSymbolValue(Sym: getSymbol(GV: &F), Size: TM.getProgramPointerSize());
1827 const auto *TypeId = extractNumericCGTypeId(F);
1828 if (IsIndirectTarget && TypeId)
1829 OutStreamer->emitInt64(Value: TypeId->getZExtValue());
1830 else
1831 OutStreamer->emitInt64(Value: 0);
1832
1833 if (DirectCallees.size() > 0) {
1834 OutStreamer->emitULEB128IntValue(Value: DirectCallees.size());
1835 for (const auto &CalleeSymbol : DirectCallees)
1836 OutStreamer->emitSymbolValue(Sym: CalleeSymbol, Size: TM.getProgramPointerSize());
1837 FuncCGInfo.DirectCallees.clear();
1838 }
1839 if (IndirectCalleeTypeIDs.size() > 0) {
1840 OutStreamer->emitULEB128IntValue(Value: IndirectCalleeTypeIDs.size());
1841 for (const auto &CalleeTypeId : IndirectCalleeTypeIDs)
1842 OutStreamer->emitInt64(Value: CalleeTypeId);
1843 FuncCGInfo.IndirectCalleeTypeIDs.clear();
1844 }
1845 // End of emitting call graph section contents.
1846 OutStreamer->popSection();
1847}
1848
1849void AsmPrinter::emitPCSectionsLabel(const MachineFunction &MF,
1850 const MDNode &MD) {
1851 MCSymbol *S = MF.getContext().createTempSymbol(Name: "pcsection");
1852 OutStreamer->emitLabel(Symbol: S);
1853 PCSectionsSymbols[&MD].emplace_back(Args&: S);
1854}
1855
1856void AsmPrinter::emitPCSections(const MachineFunction &MF) {
1857 const Function &F = MF.getFunction();
1858 if (PCSectionsSymbols.empty() && !F.hasMetadata(KindID: LLVMContext::MD_pcsections))
1859 return;
1860
1861 const CodeModel::Model CM = MF.getTarget().getCodeModel();
1862 const unsigned RelativeRelocSize =
1863 (CM == CodeModel::Medium || CM == CodeModel::Large) ? getPointerSize()
1864 : 4;
1865
1866 // Switch to PCSection, short-circuiting the common case where the current
1867 // section is still valid (assume most MD_pcsections contain just 1 section).
1868 auto SwitchSection = [&, Prev = StringRef()](const StringRef &Sec) mutable {
1869 if (Sec == Prev)
1870 return;
1871 MCSection *S = getObjFileLowering().getPCSection(Name: Sec, TextSec: MF.getSection());
1872 assert(S && "PC section is not initialized");
1873 OutStreamer->switchSection(Section: S);
1874 Prev = Sec;
1875 };
1876 // Emit symbols into sections and data as specified in the pcsections MDNode.
1877 auto EmitForMD = [&](const MDNode &MD, ArrayRef<const MCSymbol *> Syms,
1878 bool Deltas) {
1879 // Expect the first operand to be a section name. After that, a tuple of
1880 // constants may appear, which will simply be emitted into the current
1881 // section (the user of MD_pcsections decides the format of encoded data).
1882 assert(isa<MDString>(MD.getOperand(0)) && "first operand not a string");
1883 bool ConstULEB128 = false;
1884 for (const MDOperand &MDO : MD.operands()) {
1885 if (auto *S = dyn_cast<MDString>(Val: MDO)) {
1886 // Found string, start of new section!
1887 // Find options for this section "<section>!<opts>" - supported options:
1888 // C = Compress constant integers of size 2-8 bytes as ULEB128.
1889 const StringRef SecWithOpt = S->getString();
1890 const size_t OptStart = SecWithOpt.find(C: '!'); // likely npos
1891 const StringRef Sec = SecWithOpt.substr(Start: 0, N: OptStart);
1892 const StringRef Opts = SecWithOpt.substr(Start: OptStart); // likely empty
1893 ConstULEB128 = Opts.contains(C: 'C');
1894#ifndef NDEBUG
1895 for (char O : Opts)
1896 assert((O == '!' || O == 'C') && "Invalid !pcsections options");
1897#endif
1898 SwitchSection(Sec);
1899 const MCSymbol *Prev = Syms.front();
1900 for (const MCSymbol *Sym : Syms) {
1901 if (Sym == Prev || !Deltas) {
1902 // Use the entry itself as the base of the relative offset.
1903 MCSymbol *Base = MF.getContext().createTempSymbol(Name: "pcsection_base");
1904 OutStreamer->emitLabel(Symbol: Base);
1905 // Emit relative relocation `addr - base`, which avoids a dynamic
1906 // relocation in the final binary. User will get the address with
1907 // `base + addr`.
1908 emitLabelDifference(Hi: Sym, Lo: Base, Size: RelativeRelocSize);
1909 } else {
1910 // Emit delta between symbol and previous symbol.
1911 if (ConstULEB128)
1912 emitLabelDifferenceAsULEB128(Hi: Sym, Lo: Prev);
1913 else
1914 emitLabelDifference(Hi: Sym, Lo: Prev, Size: 4);
1915 }
1916 Prev = Sym;
1917 }
1918 } else {
1919 // Emit auxiliary data after PC.
1920 assert(isa<MDNode>(MDO) && "expecting either string or tuple");
1921 const auto *AuxMDs = cast<MDNode>(Val: MDO);
1922 for (const MDOperand &AuxMDO : AuxMDs->operands()) {
1923 assert(isa<ConstantAsMetadata>(AuxMDO) && "expecting a constant");
1924 const Constant *C = cast<ConstantAsMetadata>(Val: AuxMDO)->getValue();
1925 const DataLayout &DL = F.getDataLayout();
1926 const uint64_t Size = DL.getTypeStoreSize(Ty: C->getType());
1927
1928 if (auto *CI = dyn_cast<ConstantInt>(Val: C);
1929 CI && ConstULEB128 && Size > 1 && Size <= 8) {
1930 emitULEB128(Value: CI->getZExtValue());
1931 } else {
1932 emitGlobalConstant(DL, CV: C);
1933 }
1934 }
1935 }
1936 }
1937 };
1938
1939 OutStreamer->pushSection();
1940 // Emit PCs for function start and function size.
1941 if (const MDNode *MD = F.getMetadata(KindID: LLVMContext::MD_pcsections))
1942 EmitForMD(*MD, {getFunctionBegin(), getFunctionEnd()}, true);
1943 // Emit PCs for instructions collected.
1944 for (const auto &MS : PCSectionsSymbols)
1945 EmitForMD(*MS.first, MS.second, false);
1946 OutStreamer->popSection();
1947 PCSectionsSymbols.clear();
1948}
1949
1950/// Returns true if function begin and end labels should be emitted.
1951static bool needFuncLabels(const MachineFunction &MF, const AsmPrinter &Asm) {
1952 if (Asm.hasDebugInfo() || !MF.getLandingPads().empty() ||
1953 MF.hasEHFunclets() ||
1954 MF.getFunction().hasMetadata(KindID: LLVMContext::MD_pcsections))
1955 return true;
1956
1957 // We might emit an EH table that uses function begin and end labels even if
1958 // we don't have any landingpads.
1959 if (!MF.getFunction().hasPersonalityFn())
1960 return false;
1961 return !isNoOpWithoutInvoke(
1962 Pers: classifyEHPersonality(Pers: MF.getFunction().getPersonalityFn()));
1963}
1964
1965// Return the mnemonic of a MachineInstr if available, or the MachineInstr
1966// opcode name otherwise.
1967static StringRef getMIMnemonic(const MachineInstr &MI, MCStreamer &Streamer) {
1968 const TargetInstrInfo *TII =
1969 MI.getParent()->getParent()->getSubtarget().getInstrInfo();
1970 MCInst MCI;
1971 MCI.setOpcode(MI.getOpcode());
1972 if (StringRef Name = Streamer.getMnemonic(MI: MCI); !Name.empty())
1973 return Name;
1974 StringRef Name = TII->getName(Opcode: MI.getOpcode());
1975 assert(!Name.empty() && "Missing mnemonic and name for opcode");
1976 return Name;
1977}
1978
1979void AsmPrinter::handleCallsiteForCallgraph(
1980 FunctionCallGraphInfo &FuncCGInfo,
1981 const MachineFunction::CallSiteInfoMap &CallSitesInfoMap,
1982 const MachineInstr &MI) {
1983 assert(MI.isCall() && "This method is meant for call instructions only.");
1984 const MachineOperand &CalleeOperand = MI.getOperand(i: 0);
1985 if (CalleeOperand.isGlobal() || CalleeOperand.isSymbol()) {
1986 // Handle direct calls.
1987 MCSymbol *CalleeSymbol = nullptr;
1988 switch (CalleeOperand.getType()) {
1989 case llvm::MachineOperand::MO_GlobalAddress:
1990 CalleeSymbol = getSymbol(GV: CalleeOperand.getGlobal());
1991 break;
1992 case llvm::MachineOperand::MO_ExternalSymbol:
1993 CalleeSymbol = GetExternalSymbolSymbol(Sym: CalleeOperand.getSymbolName());
1994 break;
1995 default:
1996 llvm_unreachable(
1997 "Expected to only handle direct call instructions here.");
1998 }
1999 FuncCGInfo.DirectCallees.insert(X: CalleeSymbol);
2000 return; // Early exit after handling the direct call instruction.
2001 }
2002 const auto &CallSiteInfo = CallSitesInfoMap.find(Val: &MI);
2003 if (CallSiteInfo == CallSitesInfoMap.end())
2004 return;
2005 // Handle indirect callsite info.
2006 // Only indirect calls have type identifiers set.
2007 for (ConstantInt *CalleeTypeId : CallSiteInfo->second.CalleeTypeIds) {
2008 uint64_t CalleeTypeIdVal = CalleeTypeId->getZExtValue();
2009 FuncCGInfo.IndirectCalleeTypeIDs.insert(X: CalleeTypeIdVal);
2010 }
2011}
2012
2013/// Helper to emit a symbol for the prefetch target associated with the given
2014/// BBID and callsite index.
2015void AsmPrinter::emitPrefetchTargetSymbol(const UniqueBBID &BBID,
2016 unsigned CallsiteIndex) {
2017 SmallString<128> FunctionName;
2018 getNameWithPrefix(Name&: FunctionName, GV: &MF->getFunction());
2019 MCSymbol *PrefetchTargetSymbol = OutContext.getOrCreateSymbol(
2020 Name: getPrefetchTargetSymbolName(FunctionName, BBID, CallsiteIndex));
2021 // If the function is weak-linkage it may be replaced by a strong
2022 // version, in which case the prefetch targets should also be replaced.
2023 OutStreamer->emitSymbolAttribute(
2024 Symbol: PrefetchTargetSymbol,
2025 Attribute: MF->getFunction().isWeakForLinker() ? MCSA_Weak : MCSA_Global);
2026 OutStreamer->emitLabel(Symbol: PrefetchTargetSymbol);
2027}
2028
2029/// Emit dangling prefetch targets that were not mapped to any basic block.
2030void AsmPrinter::emitDanglingPrefetchTargets() {
2031 const DenseMap<UniqueBBID, SmallVector<unsigned>> &MFPrefetchTargets =
2032 MF->getPrefetchTargets();
2033 if (MFPrefetchTargets.empty())
2034 return;
2035 DenseSet<UniqueBBID> MFBBIDs;
2036 for (const MachineBasicBlock &MBB : *MF)
2037 if (std::optional<UniqueBBID> BBID = MBB.getBBID())
2038 MFBBIDs.insert(V: *BBID);
2039
2040 for (const auto &[BBID, CallsiteIndexes] : MFPrefetchTargets) {
2041 if (MFBBIDs.contains(V: BBID))
2042 continue;
2043 for (unsigned CallsiteIndex : CallsiteIndexes)
2044 emitPrefetchTargetSymbol(BBID, CallsiteIndex);
2045 }
2046}
2047
2048/// EmitFunctionBody - This method emits the body and trailer for a
2049/// function.
2050void AsmPrinter::emitFunctionBody() {
2051 emitFunctionHeader();
2052
2053 // Emit target-specific gunk before the function body.
2054 emitFunctionBodyStart();
2055
2056 if (isVerbose()) {
2057 // Get MachineDominatorTree or compute it on the fly if it's unavailable
2058 MDT = GetMDT(*MF);
2059 if (!MDT) {
2060 OwnedMDT = std::make_unique<MachineDominatorTree>();
2061 OwnedMDT->recalculate(Func&: *MF);
2062 MDT = OwnedMDT.get();
2063 }
2064
2065 // Get MachineLoopInfo or compute it on the fly if it's unavailable
2066 MLI = GetMLI(*MF);
2067 if (!MLI) {
2068 OwnedMLI = std::make_unique<MachineLoopInfo>();
2069 OwnedMLI->analyze(DomTree: *MDT);
2070 MLI = OwnedMLI.get();
2071 }
2072 }
2073
2074 // Print out code for the function.
2075 bool HasAnyRealCode = false;
2076 int NumInstsInFunction = 0;
2077 bool IsEHa = MMI->getModule()->getModuleFlag(Key: "eh-asynch");
2078
2079 const MCSubtargetInfo *STI = nullptr;
2080 if (this->MF)
2081 STI = &getSubtargetInfo();
2082 else
2083 STI = &TM.getMCSubtargetInfo();
2084
2085 bool CanDoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
2086 // Create a slot for the entry basic block section so that the section
2087 // order is preserved when iterating over MBBSectionRanges.
2088 if (!MF->empty())
2089 MBBSectionRanges[MF->front().getSectionID()] =
2090 MBBSectionRange{.BeginLabel: CurrentFnBegin, .EndLabel: nullptr};
2091
2092 FunctionCallGraphInfo FuncCGInfo;
2093 const auto &CallSitesInfoMap = MF->getCallSitesInfo();
2094
2095 // Dangling targets are not mapped to any blocks and must be emitted at the
2096 // beginning of the function.
2097 emitDanglingPrefetchTargets();
2098
2099 const auto &MFPrefetchTargets = MF->getPrefetchTargets();
2100 for (auto &MBB : *MF) {
2101 // Print a label for the basic block.
2102 emitBasicBlockStart(MBB);
2103 DenseMap<StringRef, unsigned> MnemonicCounts;
2104
2105 const SmallVector<unsigned> *PrefetchTargets = nullptr;
2106 if (auto BBID = MBB.getBBID()) {
2107 auto R = MFPrefetchTargets.find(Val: *BBID);
2108 if (R != MFPrefetchTargets.end())
2109 PrefetchTargets = &R->second;
2110 }
2111 auto PrefetchTargetIt =
2112 PrefetchTargets ? PrefetchTargets->begin() : nullptr;
2113 auto PrefetchTargetEnd = PrefetchTargets ? PrefetchTargets->end() : nullptr;
2114 unsigned LastCallsiteIndex = 0;
2115
2116 for (auto &MI : MBB) {
2117 if (PrefetchTargetIt != PrefetchTargetEnd &&
2118 *PrefetchTargetIt == LastCallsiteIndex) {
2119 emitPrefetchTargetSymbol(BBID: *MBB.getBBID(), CallsiteIndex: *PrefetchTargetIt);
2120 ++PrefetchTargetIt;
2121 }
2122
2123 // Print the assembly for the instruction.
2124 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
2125 !MI.isDebugInstr()) {
2126 HasAnyRealCode = true;
2127 }
2128
2129 // If there is a pre-instruction symbol, emit a label for it here.
2130 if (MCSymbol *S = MI.getPreInstrSymbol())
2131 OutStreamer->emitLabel(Symbol: S);
2132
2133 if (MDNode *MD = MI.getPCSections())
2134 emitPCSectionsLabel(MF: *MF, MD: *MD);
2135
2136 for (auto &Handler : Handlers)
2137 Handler->beginInstruction(MI: &MI);
2138
2139 if (isVerbose())
2140 emitComments(MI, STI, CommentOS&: OutStreamer->getCommentOS());
2141
2142#ifndef NDEBUG
2143 MCFragment *OldFragment = OutStreamer->getCurrentFragment();
2144 size_t OldFragSize = OldFragment->getFixedSize();
2145#endif
2146
2147 switch (MI.getOpcode()) {
2148 case TargetOpcode::CFI_INSTRUCTION:
2149 emitCFIInstruction(MI);
2150 break;
2151 case TargetOpcode::LOCAL_ESCAPE:
2152 emitFrameAlloc(MI);
2153 break;
2154 case TargetOpcode::ANNOTATION_LABEL:
2155 case TargetOpcode::GC_LABEL:
2156 OutStreamer->emitLabel(Symbol: MI.getOperand(i: 0).getMCSymbol());
2157 break;
2158 case TargetOpcode::EH_LABEL:
2159 OutStreamer->AddComment(T: "EH_LABEL");
2160 OutStreamer->emitLabel(Symbol: MI.getOperand(i: 0).getMCSymbol());
2161 // For AsynchEH, insert a Nop if followed by a trap inst
2162 // Or the exception won't be caught.
2163 // (see MCConstantExpr::create(1,..) in WinException.cpp)
2164 // Ignore SDiv/UDiv because a DIV with Const-0 divisor
2165 // must have being turned into an UndefValue.
2166 // Div with variable opnds won't be the first instruction in
2167 // an EH region as it must be led by at least a Load
2168 {
2169 auto MI2 = std::next(x: MI.getIterator());
2170 if (IsEHa && MI2 != MBB.end() &&
2171 (MI2->mayLoadOrStore() || MI2->mayRaiseFPException()))
2172 emitNops(N: 1);
2173 }
2174 break;
2175 case TargetOpcode::INLINEASM:
2176 case TargetOpcode::INLINEASM_BR:
2177 emitInlineAsm(MI: &MI);
2178 break;
2179 case TargetOpcode::DBG_VALUE:
2180 case TargetOpcode::DBG_VALUE_LIST:
2181 if (isVerbose()) {
2182 if (!emitDebugValueComment(MI: &MI, AP&: *this))
2183 emitInstruction(&MI);
2184 }
2185 break;
2186 case TargetOpcode::DBG_INSTR_REF:
2187 // This instruction reference will have been resolved to a machine
2188 // location, and a nearby DBG_VALUE created. We can safely ignore
2189 // the instruction reference.
2190 break;
2191 case TargetOpcode::DBG_PHI:
2192 // This instruction is only used to label a program point, it's purely
2193 // meta information.
2194 break;
2195 case TargetOpcode::DBG_LABEL:
2196 if (isVerbose()) {
2197 if (!emitDebugLabelComment(MI: &MI, AP&: *this))
2198 emitInstruction(&MI);
2199 }
2200 break;
2201 case TargetOpcode::IMPLICIT_DEF:
2202 if (isVerbose()) emitImplicitDef(MI: &MI);
2203 break;
2204 case TargetOpcode::KILL:
2205 if (isVerbose()) emitKill(MI: &MI, AP&: *this);
2206 break;
2207 case TargetOpcode::FAKE_USE:
2208 if (isVerbose())
2209 emitFakeUse(MI: &MI, AP&: *this);
2210 break;
2211 case TargetOpcode::PSEUDO_PROBE:
2212 emitPseudoProbe(MI);
2213 break;
2214 case TargetOpcode::ARITH_FENCE:
2215 if (isVerbose())
2216 OutStreamer->emitRawComment(T: "ARITH_FENCE");
2217 break;
2218 case TargetOpcode::MEMBARRIER:
2219 OutStreamer->emitRawComment(T: "MEMBARRIER");
2220 break;
2221 case TargetOpcode::JUMP_TABLE_DEBUG_INFO:
2222 // This instruction is only used to note jump table debug info, it's
2223 // purely meta information.
2224 break;
2225 case TargetOpcode::INIT_UNDEF:
2226 // This is only used to influence register allocation behavior, no
2227 // actual initialization is needed.
2228 break;
2229 case TargetOpcode::RELOC_NONE: {
2230 // Generate a temporary label for the current PC.
2231 MCSymbol *Sym = OutContext.createTempSymbol(Name: "reloc_none");
2232 OutStreamer->emitLabel(Symbol: Sym);
2233 const MCExpr *Dot = MCSymbolRefExpr::create(Symbol: Sym, Ctx&: OutContext);
2234 const MCExpr *Value = MCSymbolRefExpr::create(
2235 Symbol: OutContext.getOrCreateSymbol(Name: MI.getOperand(i: 0).getSymbolName()),
2236 Ctx&: OutContext);
2237 OutStreamer->emitRelocDirective(Offset: *Dot, Name: "BFD_RELOC_NONE", Expr: Value, Loc: SMLoc());
2238 break;
2239 }
2240 default:
2241 emitInstruction(&MI);
2242
2243 auto CountInstruction = [&](const MachineInstr &MI) {
2244 // Skip Meta instructions inside bundles.
2245 if (MI.isMetaInstruction())
2246 return;
2247 ++NumInstsInFunction;
2248 if (CanDoExtraAnalysis) {
2249 StringRef Name = getMIMnemonic(MI, Streamer&: *OutStreamer);
2250 ++MnemonicCounts[Name];
2251 }
2252 };
2253 if (!MI.isBundle()) {
2254 CountInstruction(MI);
2255 break;
2256 }
2257 // Separately count all the instructions in a bundle.
2258 for (auto It = std::next(x: MI.getIterator());
2259 It != MBB.end() && It->isInsideBundle(); ++It) {
2260 CountInstruction(*It);
2261 }
2262 break;
2263 }
2264
2265#ifndef NDEBUG
2266 // Verify that the instruction size reported by InstrInfo matches the
2267 // actually emitted size. Many backends performing branch relaxation
2268 // on the MIR level rely on this for correctness.
2269 // TODO: We currently can't distinguish whether a parse error occurred
2270 // when handling INLINEASM.
2271 if (OutStreamer->isObj() && !OutContext.hadError() &&
2272 (MI.getOpcode() != TargetOpcode::INLINEASM &&
2273 MI.getOpcode() != TargetOpcode::INLINEASM_BR)) {
2274 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
2275 TargetInstrInfo::InstSizeVerifyMode Mode =
2276 TII->getInstSizeVerifyMode(MI);
2277 if (Mode != TargetInstrInfo::InstSizeVerifyMode::NoVerify) {
2278 unsigned ExpectedSize = TII->getInstSizeInBytes(MI);
2279 MCFragment *NewFragment = OutStreamer->getCurrentFragment();
2280 unsigned ActualSize;
2281 if (OldFragment == NewFragment) {
2282 ActualSize = NewFragment->getFixedSize() - OldFragSize;
2283 } else {
2284 ActualSize = OldFragment->getFixedSize() - OldFragSize;
2285 const MCFragment *F = OldFragment->getNext();
2286 for (; F != NewFragment; F = F->getNext())
2287 ActualSize += F->getFixedSize();
2288 ActualSize += NewFragment->getFixedSize();
2289 }
2290 bool AllowOverEstimate =
2291 Mode == TargetInstrInfo::InstSizeVerifyMode::AllowOverEstimate;
2292 bool Valid = AllowOverEstimate ? ActualSize <= ExpectedSize
2293 : ActualSize == ExpectedSize;
2294 if (!Valid) {
2295 dbgs() << "In function: " << MF->getName() << "\n";
2296 dbgs() << "Size mismatch for: " << MI;
2297 if (MI.isBundled()) {
2298 dbgs() << "{\n";
2299 auto It = MI.getIterator(), End = MBB.instr_end();
2300 for (++It; It != End && It->isInsideBundle(); ++It)
2301 dbgs().indent(2) << *It;
2302 dbgs() << "}\n";
2303 }
2304 dbgs() << "Expected " << (AllowOverEstimate ? "maximum" : "exact")
2305 << " size: " << ExpectedSize << "\n";
2306 dbgs() << "Actual size: " << ActualSize << "\n";
2307 abort();
2308 }
2309 }
2310 }
2311#endif
2312
2313 if (MI.isCall()) {
2314 if (MF->getTarget().Options.BBAddrMap)
2315 OutStreamer->emitLabel(Symbol: createCallsiteEndSymbol(MBB));
2316 LastCallsiteIndex++;
2317 }
2318
2319 if (TM.Options.EmitCallGraphSection && MI.isCall())
2320 handleCallsiteForCallgraph(FuncCGInfo, CallSitesInfoMap, MI);
2321
2322 // If there is a post-instruction symbol, emit a label for it here.
2323 if (MCSymbol *S = MI.getPostInstrSymbol()) {
2324 // Emit the weak symbol attribute used for the prefetch target fallback.
2325 if (TM.getTargetTriple().isOSBinFormatELF()) {
2326 MCSymbolELF *ESym = static_cast<MCSymbolELF *>(S);
2327 if (ESym->getBinding() == ELF::STB_WEAK)
2328 OutStreamer->emitSymbolAttribute(Symbol: S, Attribute: MCSA_Weak);
2329 }
2330 OutStreamer->emitLabel(Symbol: S);
2331 }
2332
2333 for (auto &Handler : Handlers)
2334 Handler->endInstruction();
2335 }
2336 // Emit the remaining prefetch targets for this block. This includes
2337 // nonexisting callsite indexes.
2338 while (PrefetchTargetIt != PrefetchTargetEnd) {
2339 emitPrefetchTargetSymbol(BBID: *MBB.getBBID(), CallsiteIndex: *PrefetchTargetIt);
2340 ++PrefetchTargetIt;
2341 }
2342
2343 // We must emit temporary symbol for the end of this basic block, if either
2344 // we have BBLabels enabled or if this basic blocks marks the end of a
2345 // section.
2346 if (MF->getTarget().Options.BBAddrMap ||
2347 (MAI.hasDotTypeDotSizeDirective() && MBB.isEndSection()))
2348 OutStreamer->emitLabel(Symbol: MBB.getEndSymbol());
2349
2350 if (MBB.isEndSection()) {
2351 // The size directive for the section containing the entry block is
2352 // handled separately by the function section.
2353 if (!MBB.sameSection(MBB: &MF->front())) {
2354 if (MAI.hasDotTypeDotSizeDirective()) {
2355 // Emit the size directive for the basic block section.
2356 const MCExpr *SizeExp = MCBinaryExpr::createSub(
2357 LHS: MCSymbolRefExpr::create(Symbol: MBB.getEndSymbol(), Ctx&: OutContext),
2358 RHS: MCSymbolRefExpr::create(Symbol: CurrentSectionBeginSym, Ctx&: OutContext),
2359 Ctx&: OutContext);
2360 OutStreamer->emitELFSize(Symbol: CurrentSectionBeginSym, Value: SizeExp);
2361 }
2362 assert(!MBBSectionRanges.contains(MBB.getSectionID()) &&
2363 "Overwrite section range");
2364 MBBSectionRanges[MBB.getSectionID()] =
2365 MBBSectionRange{.BeginLabel: CurrentSectionBeginSym, .EndLabel: MBB.getEndSymbol()};
2366 }
2367 }
2368 emitBasicBlockEnd(MBB);
2369
2370 if (CanDoExtraAnalysis) {
2371 // Skip empty blocks.
2372 if (MBB.empty())
2373 continue;
2374
2375 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE, "InstructionMix",
2376 MBB.begin()->getDebugLoc(), &MBB);
2377
2378 // Generate instruction mix remark. First, sort counts in descending order
2379 // by count and name.
2380 SmallVector<std::pair<StringRef, unsigned>, 128> MnemonicVec;
2381 for (auto &KV : MnemonicCounts)
2382 MnemonicVec.emplace_back(Args&: KV.first, Args&: KV.second);
2383
2384 sort(C&: MnemonicVec, Comp: [](const std::pair<StringRef, unsigned> &A,
2385 const std::pair<StringRef, unsigned> &B) {
2386 if (A.second > B.second)
2387 return true;
2388 if (A.second == B.second)
2389 return StringRef(A.first) < StringRef(B.first);
2390 return false;
2391 });
2392 R << "BasicBlock: " << ore::NV("BasicBlock", MBB.getName()) << "\n";
2393 for (auto &KV : MnemonicVec) {
2394 auto Name = (Twine("INST_") + getToken(Source: KV.first.trim()).first).str();
2395 R << KV.first << ": " << ore::NV(Name, KV.second) << "\n";
2396 }
2397 ORE->emit(OptDiag&: R);
2398 }
2399 }
2400
2401 EmittedInsts += NumInstsInFunction;
2402 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE, "InstructionCount",
2403 MF->getFunction().getSubprogram(),
2404 &MF->front());
2405 R << ore::NV("NumInstructions", NumInstsInFunction)
2406 << " instructions in function";
2407 ORE->emit(OptDiag&: R);
2408
2409 // If the function is empty and the object file uses .subsections_via_symbols,
2410 // then we need to emit *something* to the function body to prevent the
2411 // labels from collapsing together. Just emit a noop.
2412 // Similarly, don't emit empty functions on Windows either. It can lead to
2413 // duplicate entries (two functions with the same RVA) in the Guard CF Table
2414 // after linking, causing the kernel not to load the binary:
2415 // https://developercommunity.visualstudio.com/content/problem/45366/vc-linker-creates-invalid-dll-with-clang-cl.html
2416 // FIXME: Hide this behind some API in e.g. MCAsmInfo or MCTargetStreamer.
2417 const Triple &TT = TM.getTargetTriple();
2418 if (!HasAnyRealCode && (MAI.hasSubsectionsViaSymbols() ||
2419 (TT.isOSWindows() && TT.isOSBinFormatCOFF()))) {
2420 MCInst Noop = MF->getSubtarget().getInstrInfo()->getNop();
2421
2422 // Targets can opt-out of emitting the noop here by leaving the opcode
2423 // unspecified.
2424 if (Noop.getOpcode()) {
2425 OutStreamer->AddComment(T: "avoids zero-length function");
2426 emitNops(N: 1);
2427 }
2428 }
2429
2430 // Switch to the original section in case basic block sections was used.
2431 OutStreamer->switchSection(Section: MF->getSection());
2432
2433 const Function &F = MF->getFunction();
2434 for (const auto &BB : F) {
2435 if (!BB.hasAddressTaken())
2436 continue;
2437 MCSymbol *Sym = GetBlockAddressSymbol(BB: &BB);
2438 if (Sym->isDefined())
2439 continue;
2440 OutStreamer->AddComment(T: "Address of block that was removed by CodeGen");
2441 OutStreamer->emitLabel(Symbol: Sym);
2442 }
2443
2444 // Emit target-specific gunk after the function body.
2445 emitFunctionBodyEnd();
2446
2447 // Even though wasm supports .type and .size in general, function symbols
2448 // are automatically sized.
2449 bool EmitFunctionSize = MAI.hasDotTypeDotSizeDirective() && !TT.isWasm();
2450
2451 // SPIR-V supports label instructions only inside a block, not after the
2452 // function body.
2453 if (TT.getObjectFormat() != Triple::SPIRV &&
2454 (EmitFunctionSize || needFuncLabels(MF: *MF, Asm: *this) || CurrentFnEnd)) {
2455 // Create a symbol for the end of function, if not already pre-created
2456 // (e.g. for .prefalign directive).
2457 if (!CurrentFnEnd)
2458 CurrentFnEnd = createTempSymbol(Name: "func_end");
2459 OutStreamer->emitLabel(Symbol: CurrentFnEnd);
2460 }
2461
2462 // If the target wants a .size directive for the size of the function, emit
2463 // it.
2464 if (EmitFunctionSize) {
2465 // We can get the size as difference between the function label and the
2466 // temp label.
2467 const MCExpr *SizeExp = MCBinaryExpr::createSub(
2468 LHS: MCSymbolRefExpr::create(Symbol: CurrentFnEnd, Ctx&: OutContext),
2469 RHS: MCSymbolRefExpr::create(Symbol: CurrentFnSymForSize, Ctx&: OutContext), Ctx&: OutContext);
2470 OutStreamer->emitELFSize(Symbol: CurrentFnSym, Value: SizeExp);
2471 if (CurrentFnBeginLocal)
2472 OutStreamer->emitELFSize(Symbol: CurrentFnBeginLocal, Value: SizeExp);
2473 }
2474
2475 // Call endBasicBlockSection on the last block now, if it wasn't already
2476 // called.
2477 if (!MF->back().isEndSection()) {
2478 for (auto &Handler : Handlers)
2479 Handler->endBasicBlockSection(MBB: MF->back());
2480 for (auto &Handler : EHHandlers)
2481 Handler->endBasicBlockSection(MBB: MF->back());
2482 }
2483 for (auto &Handler : Handlers)
2484 Handler->markFunctionEnd();
2485 for (auto &Handler : EHHandlers)
2486 Handler->markFunctionEnd();
2487 // Update the end label of the entry block's section.
2488 MBBSectionRanges[MF->front().getSectionID()].EndLabel = CurrentFnEnd;
2489
2490 // Print out jump tables referenced by the function.
2491 emitJumpTableInfo();
2492
2493 // Emit post-function debug and/or EH information.
2494 for (auto &Handler : Handlers)
2495 Handler->endFunction(MF);
2496 for (auto &Handler : EHHandlers)
2497 Handler->endFunction(MF);
2498
2499 // Emit section containing BB address offsets and their metadata, when
2500 // BB labels are requested for this function. Skip empty functions.
2501 if (HasAnyRealCode) {
2502 if (MF->getTarget().Options.BBAddrMap)
2503 emitBBAddrMapSection(MF: *MF);
2504 else if (PgoAnalysisMapFeatures.getBits() != 0)
2505 MF->getContext().reportWarning(
2506 L: SMLoc(), Msg: "pgo-analysis-map is enabled for function " + MF->getName() +
2507 " but it does not have labels");
2508 }
2509
2510 // Emit sections containing instruction and function PCs.
2511 emitPCSections(MF: *MF);
2512
2513 // Emit section containing stack size metadata.
2514 emitStackSizeSection(MF: *MF);
2515
2516 // Emit section containing call graph metadata.
2517 emitCallGraphSection(MF: *MF, FuncCGInfo);
2518
2519 // Emit .su file containing function stack size information.
2520 emitStackUsage(MF: *MF);
2521
2522 emitPatchableFunctionEntries();
2523
2524 if (isVerbose())
2525 OutStreamer->getCommentOS() << "-- End function\n";
2526
2527 OutStreamer->addBlankLine();
2528}
2529
2530/// Compute the number of Global Variables that uses a Constant.
2531static unsigned getNumGlobalVariableUses(const Constant *C,
2532 bool &HasNonGlobalUsers) {
2533 if (!C) {
2534 HasNonGlobalUsers = true;
2535 return 0;
2536 }
2537
2538 if (isa<GlobalVariable>(Val: C))
2539 return 1;
2540
2541 unsigned NumUses = 0;
2542 for (const auto *CU : C->users())
2543 NumUses +=
2544 getNumGlobalVariableUses(C: dyn_cast<Constant>(Val: CU), HasNonGlobalUsers);
2545
2546 return NumUses;
2547}
2548
2549/// Only consider global GOT equivalents if at least one user is a
2550/// cstexpr inside an initializer of another global variables. Also, don't
2551/// handle cstexpr inside instructions. During global variable emission,
2552/// candidates are skipped and are emitted later in case at least one cstexpr
2553/// isn't replaced by a PC relative GOT entry access.
2554static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
2555 unsigned &NumGOTEquivUsers,
2556 bool &HasNonGlobalUsers) {
2557 // Global GOT equivalents are unnamed private globals with a constant
2558 // pointer initializer to another global symbol. They must point to a
2559 // GlobalVariable or Function, i.e., as GlobalValue.
2560 if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
2561 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
2562 !isa<GlobalValue>(Val: GV->getOperand(i_nocapture: 0)))
2563 return false;
2564
2565 // To be a got equivalent, at least one of its users need to be a constant
2566 // expression used by another global variable.
2567 for (const auto *U : GV->users())
2568 NumGOTEquivUsers +=
2569 getNumGlobalVariableUses(C: dyn_cast<Constant>(Val: U), HasNonGlobalUsers);
2570
2571 return NumGOTEquivUsers > 0;
2572}
2573
2574/// Unnamed constant global variables solely contaning a pointer to
2575/// another globals variable is equivalent to a GOT table entry; it contains the
2576/// the address of another symbol. Optimize it and replace accesses to these
2577/// "GOT equivalents" by using the GOT entry for the final global instead.
2578/// Compute GOT equivalent candidates among all global variables to avoid
2579/// emitting them if possible later on, after it use is replaced by a GOT entry
2580/// access.
2581void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
2582 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
2583 return;
2584
2585 for (const auto &G : M.globals()) {
2586 unsigned NumGOTEquivUsers = 0;
2587 bool HasNonGlobalUsers = false;
2588 if (!isGOTEquivalentCandidate(GV: &G, NumGOTEquivUsers, HasNonGlobalUsers))
2589 continue;
2590 // If non-global variables use it, we still need to emit it.
2591 // Add 1 here, then emit it in `emitGlobalGOTEquivs`.
2592 if (HasNonGlobalUsers)
2593 NumGOTEquivUsers += 1;
2594 const MCSymbol *GOTEquivSym = getSymbol(GV: &G);
2595 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(x: &G, y&: NumGOTEquivUsers);
2596 }
2597}
2598
2599/// Constant expressions using GOT equivalent globals may not be eligible
2600/// for PC relative GOT entry conversion, in such cases we need to emit such
2601/// globals we previously omitted in EmitGlobalVariable.
2602void AsmPrinter::emitGlobalGOTEquivs() {
2603 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
2604 return;
2605
2606 SmallVector<const GlobalVariable *, 8> FailedCandidates;
2607 for (auto &I : GlobalGOTEquivs) {
2608 const GlobalVariable *GV = I.second.first;
2609 unsigned Cnt = I.second.second;
2610 if (Cnt)
2611 FailedCandidates.push_back(Elt: GV);
2612 }
2613 GlobalGOTEquivs.clear();
2614
2615 for (const auto *GV : FailedCandidates)
2616 emitGlobalVariable(GV);
2617}
2618
2619void AsmPrinter::emitGlobalAlias(const Module &M, const GlobalAlias &GA) {
2620 MCSymbol *Name = getSymbol(GV: &GA);
2621 const GlobalObject *BaseObject = GA.getAliaseeObject();
2622
2623 bool IsFunction = GA.getValueType()->isFunctionTy();
2624 // Treat bitcasts of functions as functions also. This is important at least
2625 // on WebAssembly where object and function addresses can't alias each other.
2626 if (!IsFunction)
2627 IsFunction = isa_and_nonnull<Function>(Val: BaseObject);
2628
2629 // AIX's assembly directive `.set` is not usable for aliasing purpose,
2630 // so AIX has to use the extra-label-at-definition strategy. At this
2631 // point, all the extra label is emitted, we just have to emit linkage for
2632 // those labels.
2633 if (TM.getTargetTriple().isOSBinFormatXCOFF()) {
2634 // Linkage for alias of global variable has been emitted.
2635 if (isa_and_nonnull<GlobalVariable>(Val: BaseObject))
2636 return;
2637
2638 emitLinkage(GV: &GA, GVSym: Name);
2639 // If it's a function, also emit linkage for aliases of function entry
2640 // point.
2641 if (IsFunction)
2642 emitLinkage(GV: &GA,
2643 GVSym: getObjFileLowering().getFunctionEntryPointSymbol(Func: &GA, TM));
2644 return;
2645 }
2646
2647 if (GA.hasExternalLinkage() || !MAI.getWeakRefDirective())
2648 OutStreamer->emitSymbolAttribute(Symbol: Name, Attribute: MCSA_Global);
2649 else if (GA.hasWeakLinkage() || GA.hasLinkOnceLinkage())
2650 OutStreamer->emitSymbolAttribute(Symbol: Name, Attribute: MCSA_WeakReference);
2651 else
2652 assert(GA.hasLocalLinkage() && "Invalid alias linkage");
2653
2654 // Set the symbol type to function if the alias has a function type.
2655 // This affects codegen when the aliasee is not a function.
2656 if (IsFunction) {
2657 OutStreamer->emitSymbolAttribute(Symbol: Name, Attribute: MCSA_ELF_TypeFunction);
2658 if (TM.getTargetTriple().isOSBinFormatCOFF()) {
2659 OutStreamer->beginCOFFSymbolDef(Symbol: Name);
2660 OutStreamer->emitCOFFSymbolStorageClass(
2661 StorageClass: GA.hasLocalLinkage() ? COFF::IMAGE_SYM_CLASS_STATIC
2662 : COFF::IMAGE_SYM_CLASS_EXTERNAL);
2663 OutStreamer->emitCOFFSymbolType(Type: COFF::IMAGE_SYM_DTYPE_FUNCTION
2664 << COFF::SCT_COMPLEX_TYPE_SHIFT);
2665 OutStreamer->endCOFFSymbolDef();
2666 }
2667 }
2668
2669 emitVisibility(Sym: Name, Visibility: GA.getVisibility());
2670
2671 const MCExpr *Expr = lowerConstant(CV: GA.getAliasee());
2672
2673 if (MAI.isMachO() && isa<MCBinaryExpr>(Val: Expr))
2674 OutStreamer->emitSymbolAttribute(Symbol: Name, Attribute: MCSA_AltEntry);
2675
2676 // Emit the directives as assignments aka .set:
2677 OutStreamer->emitAssignment(Symbol: Name, Value: Expr);
2678 MCSymbol *LocalAlias = getSymbolPreferLocal(GV: GA);
2679 if (LocalAlias != Name)
2680 OutStreamer->emitAssignment(Symbol: LocalAlias, Value: Expr);
2681
2682 // If the aliasee does not correspond to a symbol in the output, i.e. the
2683 // alias is not of an object or the aliased object is private, then set the
2684 // size of the alias symbol from the type of the alias. We don't do this in
2685 // other situations as the alias and aliasee having differing types but same
2686 // size may be intentional.
2687 if (MAI.hasDotTypeDotSizeDirective() && GA.getValueType()->isSized() &&
2688 (!BaseObject || BaseObject->hasPrivateLinkage())) {
2689 const DataLayout &DL = M.getDataLayout();
2690 uint64_t Size = DL.getTypeAllocSize(Ty: GA.getValueType());
2691 OutStreamer->emitELFSize(Symbol: Name, Value: MCConstantExpr::create(Value: Size, Ctx&: OutContext));
2692 }
2693}
2694
2695void AsmPrinter::emitGlobalIFunc(Module &M, const GlobalIFunc &GI) {
2696 auto EmitLinkage = [&](MCSymbol *Sym) {
2697 if (GI.hasExternalLinkage() || !MAI.getWeakRefDirective())
2698 OutStreamer->emitSymbolAttribute(Symbol: Sym, Attribute: MCSA_Global);
2699 else if (GI.hasWeakLinkage() || GI.hasLinkOnceLinkage())
2700 OutStreamer->emitSymbolAttribute(Symbol: Sym, Attribute: MCSA_WeakReference);
2701 else
2702 assert(GI.hasLocalLinkage() && "Invalid ifunc linkage");
2703 };
2704
2705 if (TM.getTargetTriple().isOSBinFormatELF()) {
2706 MCSymbol *Name = getSymbol(GV: &GI);
2707 EmitLinkage(Name);
2708 OutStreamer->emitSymbolAttribute(Symbol: Name, Attribute: MCSA_ELF_TypeIndFunction);
2709 emitVisibility(Sym: Name, Visibility: GI.getVisibility());
2710
2711 // Emit the directives as assignments aka .set:
2712 const MCExpr *Expr = lowerConstant(CV: GI.getResolver());
2713 OutStreamer->emitAssignment(Symbol: Name, Value: Expr);
2714 MCSymbol *LocalAlias = getSymbolPreferLocal(GV: GI);
2715 if (LocalAlias != Name)
2716 OutStreamer->emitAssignment(Symbol: LocalAlias, Value: Expr);
2717
2718 return;
2719 }
2720
2721 if (!TM.getTargetTriple().isOSBinFormatMachO() || !getIFuncMCSubtargetInfo())
2722 reportFatalUsageError(reason: "IFuncs are not supported on this platform");
2723
2724 // On Darwin platforms, emit a manually-constructed .symbol_resolver that
2725 // implements the symbol resolution duties of the IFunc.
2726 //
2727 // Normally, this would be handled by linker magic, but unfortunately there
2728 // are a few limitations in ld64 and ld-prime's implementation of
2729 // .symbol_resolver that mean we can't always use them:
2730 //
2731 // * resolvers cannot be the target of an alias
2732 // * resolvers cannot have private linkage
2733 // * resolvers cannot have linkonce linkage
2734 // * resolvers cannot appear in executables
2735 // * resolvers cannot appear in bundles
2736 //
2737 // This works around that by emitting a close approximation of what the
2738 // linker would have done.
2739
2740 MCSymbol *LazyPointer =
2741 GetExternalSymbolSymbol(Sym: GI.getName() + ".lazy_pointer");
2742 MCSymbol *StubHelper = GetExternalSymbolSymbol(Sym: GI.getName() + ".stub_helper");
2743
2744 OutStreamer->switchSection(Section: OutContext.getObjectFileInfo()->getDataSection());
2745
2746 const DataLayout &DL = M.getDataLayout();
2747 emitAlignment(Alignment: Align(DL.getPointerSize()));
2748 OutStreamer->emitLabel(Symbol: LazyPointer);
2749 emitVisibility(Sym: LazyPointer, Visibility: GI.getVisibility());
2750 OutStreamer->emitValue(Value: MCSymbolRefExpr::create(Symbol: StubHelper, Ctx&: OutContext), Size: 8);
2751
2752 OutStreamer->switchSection(Section: OutContext.getObjectFileInfo()->getTextSection());
2753
2754 const TargetSubtargetInfo *STI =
2755 TM.getSubtargetImpl(*GI.getResolverFunction());
2756 const TargetLowering *TLI = STI->getTargetLowering();
2757 Align TextAlign(TLI->getMinFunctionAlignment());
2758
2759 MCSymbol *Stub = getSymbol(GV: &GI);
2760 EmitLinkage(Stub);
2761 OutStreamer->emitCodeAlignment(Alignment: TextAlign, STI: *getIFuncMCSubtargetInfo());
2762 OutStreamer->emitLabel(Symbol: Stub);
2763 emitVisibility(Sym: Stub, Visibility: GI.getVisibility());
2764 emitMachOIFuncStubBody(M, GI, LazyPointer);
2765
2766 OutStreamer->emitCodeAlignment(Alignment: TextAlign, STI: *getIFuncMCSubtargetInfo());
2767 OutStreamer->emitLabel(Symbol: StubHelper);
2768 emitVisibility(Sym: StubHelper, Visibility: GI.getVisibility());
2769 emitMachOIFuncStubHelperBody(M, GI, LazyPointer);
2770}
2771
2772void AsmPrinter::emitRemarksSection(remarks::RemarkStreamer &RS) {
2773 if (!RS.wantsSection())
2774 return;
2775 if (!RS.getFilename())
2776 return;
2777
2778 MCSection *RemarksSection =
2779 OutContext.getObjectFileInfo()->getRemarksSection();
2780 if (!RemarksSection && RS.needsSection()) {
2781 OutContext.reportWarning(L: SMLoc(), Msg: "Current object file format does not "
2782 "support remarks sections.");
2783 }
2784 if (!RemarksSection)
2785 return;
2786
2787 SmallString<128> Filename = *RS.getFilename();
2788 sys::fs::make_absolute(path&: Filename);
2789 assert(!Filename.empty() && "The filename can't be empty.");
2790
2791 std::string Buf;
2792 raw_string_ostream OS(Buf);
2793
2794 remarks::RemarkSerializer &RemarkSerializer = RS.getSerializer();
2795 std::unique_ptr<remarks::MetaSerializer> MetaSerializer =
2796 RemarkSerializer.metaSerializer(OS, ExternalFilename: Filename);
2797 MetaSerializer->emit();
2798
2799 // Switch to the remarks section.
2800 OutStreamer->switchSection(Section: RemarksSection);
2801 OutStreamer->emitBinaryData(Data: Buf);
2802}
2803
2804static uint64_t globalSize(const llvm::GlobalVariable &G) {
2805 const Constant *Initializer = G.getInitializer();
2806 return G.getParent()->getDataLayout().getTypeAllocSize(
2807 Ty: Initializer->getType());
2808}
2809
2810static bool shouldTagGlobal(const llvm::GlobalVariable &G) {
2811 // We used to do this in clang, but there are optimization passes that turn
2812 // non-constant globals into constants. So now, clang only tells us whether
2813 // it would *like* a global to be tagged, but we still make the decision here.
2814 //
2815 // For now, don't instrument constant data, as it'll be in .rodata anyway. It
2816 // may be worth instrumenting these in future to stop them from being used as
2817 // gadgets.
2818 if (G.getName().starts_with(Prefix: "llvm.") || G.isThreadLocal() || G.isConstant())
2819 return false;
2820
2821 // Globals can be placed implicitly or explicitly in sections. There's two
2822 // different types of globals that meet this criteria that cause problems:
2823 // 1. Function pointers that are going into various init arrays (either
2824 // explicitly through `__attribute__((section(<foo>)))` or implicitly
2825 // through `__attribute__((constructor)))`, such as ".(pre)init(_array)",
2826 // ".fini(_array)", ".ctors", and ".dtors". These function pointers end up
2827 // overaligned and overpadded, making iterating over them problematic, and
2828 // each function pointer is individually tagged (so the iteration over
2829 // them causes SIGSEGV/MTE[AS]ERR).
2830 // 2. Global variables put into an explicit section, where the section's name
2831 // is a valid C-style identifier. The linker emits a `__start_<name>` and
2832 // `__stop_<name>` symbol for the section, so that you can iterate over
2833 // globals within this section. Unfortunately, again, these globals would
2834 // be tagged and so iteration causes SIGSEGV/MTE[AS]ERR.
2835 //
2836 // To mitigate both these cases, and because specifying a section is rare
2837 // outside of these two cases, disable MTE protection for globals in any
2838 // section.
2839 if (G.hasSection())
2840 return false;
2841
2842 return globalSize(G) > 0;
2843}
2844
2845static void tagGlobalDefinition(Module &M, GlobalVariable *G) {
2846 uint64_t SizeInBytes = globalSize(G: *G);
2847
2848 uint64_t NewSize = alignTo(Value: SizeInBytes, Align: 16);
2849 if (SizeInBytes != NewSize) {
2850 // Pad the initializer out to the next multiple of 16 bytes.
2851 llvm::SmallVector<uint8_t> Init(NewSize - SizeInBytes, 0);
2852 Constant *Padding = ConstantDataArray::get(Context&: M.getContext(), Elts&: Init);
2853 Constant *Initializer = G->getInitializer();
2854 Initializer = ConstantStruct::getAnon(V: {Initializer, Padding});
2855 auto *NewGV = new GlobalVariable(
2856 M, Initializer->getType(), G->isConstant(), G->getLinkage(),
2857 Initializer, "", G, G->getThreadLocalMode(), G->getAddressSpace());
2858 NewGV->copyAttributesFrom(Src: G);
2859 NewGV->setComdat(G->getComdat());
2860 NewGV->copyMetadata(Src: G, Offset: 0);
2861
2862 NewGV->takeName(V: G);
2863 G->replaceAllUsesWith(V: NewGV);
2864 G->eraseFromParent();
2865 G = NewGV;
2866 }
2867
2868 if (G->getAlign().valueOrOne() < 16)
2869 G->setAlignment(Align(16));
2870
2871 // Ensure that tagged globals don't get merged by ICF - as they should have
2872 // different tags at runtime.
2873 G->setUnnamedAddr(GlobalValue::UnnamedAddr::None);
2874}
2875
2876static void removeMemtagFromGlobal(GlobalVariable &G) {
2877 auto Meta = G.getSanitizerMetadata();
2878 Meta.Memtag = false;
2879 G.setSanitizerMetadata(Meta);
2880}
2881
2882bool AsmPrinter::doFinalization(Module &M) {
2883 // Set the MachineFunction to nullptr so that we can catch attempted
2884 // accesses to MF specific features at the module level and so that
2885 // we can conditionalize accesses based on whether or not it is nullptr.
2886 MF = nullptr;
2887 const Triple &Target = TM.getTargetTriple();
2888
2889 std::vector<GlobalVariable *> GlobalsToTag;
2890 for (GlobalVariable &G : M.globals()) {
2891 if (G.isDeclaration() || !G.isTagged())
2892 continue;
2893 if (!shouldTagGlobal(G)) {
2894 assert(G.hasSanitizerMetadata()); // because isTagged.
2895 removeMemtagFromGlobal(G);
2896 assert(!G.isTagged());
2897 continue;
2898 }
2899 GlobalsToTag.push_back(x: &G);
2900 }
2901 for (GlobalVariable *G : GlobalsToTag)
2902 tagGlobalDefinition(M, G);
2903
2904 // Gather all GOT equivalent globals in the module. We really need two
2905 // passes over the globals: one to compute and another to avoid its emission
2906 // in EmitGlobalVariable, otherwise we would not be able to handle cases
2907 // where the got equivalent shows up before its use.
2908 computeGlobalGOTEquivs(M);
2909
2910 // Emit global variables.
2911 for (const auto &G : M.globals())
2912 emitGlobalVariable(GV: &G);
2913
2914 // Emit remaining GOT equivalent globals.
2915 emitGlobalGOTEquivs();
2916
2917 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
2918
2919 // Emit linkage(XCOFF) and visibility info for declarations
2920 for (const Function &F : M) {
2921 if (!F.isDeclarationForLinker())
2922 continue;
2923
2924 MCSymbol *Name = getSymbol(GV: &F);
2925 // Function getSymbol gives us the function descriptor symbol for XCOFF.
2926
2927 if (!Target.isOSBinFormatXCOFF()) {
2928 GlobalValue::VisibilityTypes V = F.getVisibility();
2929 if (V == GlobalValue::DefaultVisibility)
2930 continue;
2931
2932 emitVisibility(Sym: Name, Visibility: V, IsDefinition: false);
2933 continue;
2934 }
2935
2936 if (F.isIntrinsic())
2937 continue;
2938
2939 // Handle the XCOFF case.
2940 // Variable `Name` is the function descriptor symbol (see above). Get the
2941 // function entry point symbol.
2942 MCSymbol *FnEntryPointSym = TLOF.getFunctionEntryPointSymbol(Func: &F, TM);
2943 // Emit linkage for the function entry point.
2944 emitLinkage(GV: &F, GVSym: FnEntryPointSym);
2945
2946 // If a function's address is taken, which means it may be called via a
2947 // function pointer, we need the function descriptor for it.
2948 if (F.hasAddressTaken())
2949 emitLinkage(GV: &F, GVSym: Name);
2950 }
2951
2952 // Emit the remarks section contents.
2953 // FIXME: Figure out when is the safest time to emit this section. It should
2954 // not come after debug info.
2955 if (remarks::RemarkStreamer *RS = M.getContext().getMainRemarkStreamer())
2956 emitRemarksSection(RS&: *RS);
2957
2958 TLOF.emitModuleMetadata(Streamer&: *OutStreamer, M);
2959
2960 if (Target.isOSBinFormatELF()) {
2961 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
2962
2963 // Output stubs for external and common global variables.
2964 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
2965 if (!Stubs.empty()) {
2966 OutStreamer->switchSection(Section: TLOF.getDataSection());
2967 const DataLayout &DL = M.getDataLayout();
2968
2969 emitAlignment(Alignment: Align(DL.getPointerSize()));
2970 for (const auto &Stub : Stubs) {
2971 OutStreamer->emitLabel(Symbol: Stub.first);
2972 OutStreamer->emitSymbolValue(Sym: Stub.second.getPointer(),
2973 Size: DL.getPointerSize());
2974 }
2975 }
2976 }
2977
2978 if (Target.isOSBinFormatCOFF()) {
2979 MachineModuleInfoCOFF &MMICOFF =
2980 MMI->getObjFileInfo<MachineModuleInfoCOFF>();
2981
2982 // Output stubs for external and common global variables.
2983 MachineModuleInfoCOFF::SymbolListTy Stubs = MMICOFF.GetGVStubList();
2984 if (!Stubs.empty()) {
2985 const DataLayout &DL = M.getDataLayout();
2986
2987 for (const auto &Stub : Stubs) {
2988 SmallString<256> SectionName = StringRef(".rdata$");
2989 SectionName += Stub.first->getName();
2990 OutStreamer->switchSection(Section: OutContext.getCOFFSection(
2991 Section: SectionName,
2992 Characteristics: COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
2993 COFF::IMAGE_SCN_LNK_COMDAT,
2994 COMDATSymName: Stub.first->getName(), Selection: COFF::IMAGE_COMDAT_SELECT_ANY));
2995 emitAlignment(Alignment: Align(DL.getPointerSize()));
2996 OutStreamer->emitSymbolAttribute(Symbol: Stub.first, Attribute: MCSA_Global);
2997 OutStreamer->emitLabel(Symbol: Stub.first);
2998 OutStreamer->emitSymbolValue(Sym: Stub.second.getPointer(),
2999 Size: DL.getPointerSize());
3000 }
3001 }
3002 }
3003
3004 // This needs to happen before emitting debug information since that can end
3005 // arbitrary sections.
3006 if (auto *TS = OutStreamer->getTargetStreamer())
3007 TS->emitConstantPools();
3008
3009 // Emit Stack maps before any debug info. Mach-O requires that no data or
3010 // text sections come after debug info has been emitted. This matters for
3011 // stack maps as they are arbitrary data, and may even have a custom format
3012 // through user plugins.
3013 EmitStackMaps(M);
3014
3015 // Print aliases in topological order, that is, for each alias a = b,
3016 // b must be printed before a.
3017 // This is because on some targets (e.g. PowerPC) linker expects aliases in
3018 // such an order to generate correct TOC information.
3019 SmallVector<const GlobalAlias *, 16> AliasStack;
3020 SmallPtrSet<const GlobalAlias *, 16> AliasVisited;
3021 for (const auto &Alias : M.aliases()) {
3022 if (Alias.hasAvailableExternallyLinkage())
3023 continue;
3024 for (const GlobalAlias *Cur = &Alias; Cur;
3025 Cur = dyn_cast<GlobalAlias>(Val: Cur->getAliasee())) {
3026 if (!AliasVisited.insert(Ptr: Cur).second)
3027 break;
3028 AliasStack.push_back(Elt: Cur);
3029 }
3030 for (const GlobalAlias *AncestorAlias : llvm::reverse(C&: AliasStack))
3031 emitGlobalAlias(M, GA: *AncestorAlias);
3032 AliasStack.clear();
3033 }
3034
3035 // IFuncs must come before deubginfo in case the backend decides to emit them
3036 // as actual functions, since on Mach-O targets, we cannot create regular
3037 // sections after DWARF.
3038 for (const auto &IFunc : M.ifuncs())
3039 emitGlobalIFunc(M, GI: IFunc);
3040 if (TM.getTargetTriple().isOSBinFormatXCOFF() && hasDebugInfo()) {
3041 // Emit section end. This is used to tell the debug line section where the
3042 // end is for a text section if we don't use .loc to represent the debug
3043 // line.
3044 auto *Sec = OutContext.getObjectFileInfo()->getTextSection();
3045 OutStreamer->switchSectionNoPrint(Section: Sec);
3046 MCSymbol *Sym = Sec->getEndSymbol(Ctx&: OutContext);
3047 OutStreamer->emitLabel(Symbol: Sym);
3048 }
3049
3050 // Finalize debug and EH information.
3051 for (auto &Handler : Handlers)
3052 Handler->endModule();
3053 for (auto &Handler : EHHandlers)
3054 Handler->endModule();
3055
3056 // This deletes all the ephemeral handlers that AsmPrinter added, while
3057 // keeping all the user-added handlers alive until the AsmPrinter is
3058 // destroyed.
3059 EHHandlers.clear();
3060 Handlers.erase(CS: Handlers.begin() + NumUserHandlers, CE: Handlers.end());
3061 DD = nullptr;
3062
3063 // If the target wants to know about weak references, print them all.
3064 if (MAI.getWeakRefDirective()) {
3065 // FIXME: This is not lazy, it would be nice to only print weak references
3066 // to stuff that is actually used. Note that doing so would require targets
3067 // to notice uses in operands (due to constant exprs etc). This should
3068 // happen with the MC stuff eventually.
3069
3070 // Print out module-level global objects here.
3071 for (const auto &GO : M.global_objects()) {
3072 if (!GO.hasExternalWeakLinkage())
3073 continue;
3074 OutStreamer->emitSymbolAttribute(Symbol: getSymbol(GV: &GO), Attribute: MCSA_WeakReference);
3075 }
3076 if (shouldEmitWeakSwiftAsyncExtendedFramePointerFlags()) {
3077 auto SymbolName = "swift_async_extendedFramePointerFlags";
3078 auto Global = M.getGlobalVariable(Name: SymbolName);
3079 if (!Global) {
3080 auto PtrTy = PointerType::getUnqual(C&: M.getContext());
3081 Global = new GlobalVariable(M, PtrTy, false,
3082 GlobalValue::ExternalWeakLinkage, nullptr,
3083 SymbolName);
3084 OutStreamer->emitSymbolAttribute(Symbol: getSymbol(GV: Global), Attribute: MCSA_WeakReference);
3085 }
3086 }
3087 }
3088
3089 FinishGCAssembly(M);
3090
3091 // Emit llvm.ident metadata in an '.ident' directive.
3092 emitModuleIdents(M);
3093
3094 // Emit bytes for llvm.commandline metadata.
3095 // The command line metadata is emitted earlier on XCOFF.
3096 if (!Target.isOSBinFormatXCOFF())
3097 emitModuleCommandLines(M);
3098
3099 // Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
3100 // split-stack is used.
3101 if (TM.getTargetTriple().isOSBinFormatELF() && HasSplitStack) {
3102 OutStreamer->switchSection(Section: OutContext.getELFSection(Section: ".note.GNU-split-stack",
3103 Type: ELF::SHT_PROGBITS, Flags: 0));
3104 if (HasNoSplitStack)
3105 OutStreamer->switchSection(Section: OutContext.getELFSection(
3106 Section: ".note.GNU-no-split-stack", Type: ELF::SHT_PROGBITS, Flags: 0));
3107 }
3108
3109 // If we don't have any trampolines, then we don't require stack memory
3110 // to be executable. Some targets have a directive to declare this.
3111 Function *InitTrampolineIntrinsic = M.getFunction(Name: "llvm.init.trampoline");
3112 bool HasTrampolineUses =
3113 InitTrampolineIntrinsic && !InitTrampolineIntrinsic->use_empty();
3114 MCSection *S = MAI.getStackSection(Ctx&: OutContext, /*Exec=*/HasTrampolineUses);
3115 if (S)
3116 OutStreamer->switchSection(Section: S);
3117
3118 if (TM.Options.EmitAddrsig) {
3119 // Emit address-significance attributes for all globals.
3120 OutStreamer->emitAddrsig();
3121 for (const GlobalValue &GV : M.global_values()) {
3122 if (!GV.use_empty() && !GV.isThreadLocal() &&
3123 !GV.hasDLLImportStorageClass() &&
3124 !GV.getName().starts_with(Prefix: "llvm.") &&
3125 !GV.hasAtLeastLocalUnnamedAddr())
3126 OutStreamer->emitAddrsigSym(Sym: getSymbol(GV: &GV));
3127 }
3128 }
3129
3130 // Emit symbol partition specifications (ELF only).
3131 if (Target.isOSBinFormatELF()) {
3132 unsigned UniqueID = 0;
3133 for (const GlobalValue &GV : M.global_values()) {
3134 if (!GV.hasPartition() || GV.isDeclarationForLinker() ||
3135 GV.getVisibility() != GlobalValue::DefaultVisibility)
3136 continue;
3137
3138 OutStreamer->switchSection(
3139 Section: OutContext.getELFSection(Section: ".llvm_sympart", Type: ELF::SHT_LLVM_SYMPART, Flags: 0, EntrySize: 0,
3140 Group: "", IsComdat: false, UniqueID: ++UniqueID, LinkedToSym: nullptr));
3141 OutStreamer->emitBytes(Data: GV.getPartition());
3142 OutStreamer->emitZeros(NumBytes: 1);
3143 OutStreamer->emitValue(
3144 Value: MCSymbolRefExpr::create(Symbol: getSymbol(GV: &GV), Ctx&: OutContext),
3145 Size: MAI.getCodePointerSize());
3146 }
3147 }
3148
3149 // Allow the target to emit any magic that it wants at the end of the file,
3150 // after everything else has gone out.
3151 emitEndOfAsmFile(M);
3152
3153 MMI = nullptr;
3154 AddrLabelSymbols = nullptr;
3155
3156 OutStreamer->finish();
3157 OutStreamer->reset();
3158 OwnedMLI.reset();
3159 OwnedMDT.reset();
3160
3161 return false;
3162}
3163
3164MCSymbol *AsmPrinter::getMBBExceptionSym(const MachineBasicBlock &MBB) {
3165 auto Res = MBBSectionExceptionSyms.try_emplace(Key: MBB.getSectionID());
3166 if (Res.second)
3167 Res.first->second = createTempSymbol(Name: "exception");
3168 return Res.first->second;
3169}
3170
3171MCSymbol *AsmPrinter::createCallsiteEndSymbol(const MachineBasicBlock &MBB) {
3172 MCContext &Ctx = MF->getContext();
3173 MCSymbol *Sym = Ctx.createTempSymbol(Name: "BB" + Twine(MF->getFunctionNumber()) +
3174 "_" + Twine(MBB.getNumber()) + "_CS");
3175 CurrentFnCallsiteEndSymbols[&MBB].push_back(Elt: Sym);
3176 return Sym;
3177}
3178
3179void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
3180 this->MF = &MF;
3181 const Function &F = MF.getFunction();
3182
3183 // Record that there are split-stack functions, so we will emit a special
3184 // section to tell the linker.
3185 if (MF.shouldSplitStack()) {
3186 HasSplitStack = true;
3187
3188 if (!MF.getFrameInfo().needsSplitStackProlog())
3189 HasNoSplitStack = true;
3190 } else
3191 HasNoSplitStack = true;
3192
3193 // Get the function symbol.
3194 if (!MAI.isAIX()) {
3195 CurrentFnSym = getSymbol(GV: &MF.getFunction());
3196 } else {
3197 assert(TM.getTargetTriple().isOSAIX() &&
3198 "Only AIX uses the function descriptor hooks.");
3199 // AIX is unique here in that the name of the symbol emitted for the
3200 // function body does not have the same name as the source function's
3201 // C-linkage name.
3202 assert(CurrentFnDescSym && "The function descriptor symbol needs to be"
3203 " initalized first.");
3204
3205 // Get the function entry point symbol.
3206 CurrentFnSym = getObjFileLowering().getFunctionEntryPointSymbol(Func: &F, TM);
3207 }
3208
3209 CurrentFnSymForSize = CurrentFnSym;
3210 CurrentFnBegin = nullptr;
3211 CurrentFnBeginLocal = nullptr;
3212 CurrentFnEnd = nullptr;
3213 CurrentSectionBeginSym = nullptr;
3214 CurrentFnCallsiteEndSymbols.clear();
3215 MBBSectionRanges.clear();
3216 MBBSectionExceptionSyms.clear();
3217 bool NeedsLocalForSize = MAI.needsLocalForSize();
3218 if (F.hasFnAttribute(Kind: "patchable-function-entry") ||
3219 F.hasFnAttribute(Kind: "function-instrument") ||
3220 F.hasFnAttribute(Kind: "xray-instruction-threshold") ||
3221 needFuncLabels(MF, Asm: *this) || NeedsLocalForSize ||
3222 MF.getTarget().Options.EmitStackSizeSection ||
3223 MF.getTarget().Options.EmitCallGraphSection ||
3224 MF.getTarget().Options.BBAddrMap) {
3225 CurrentFnBegin = createTempSymbol(Name: "func_begin");
3226 if (NeedsLocalForSize)
3227 CurrentFnSymForSize = CurrentFnBegin;
3228 }
3229
3230 ORE = GetORE(MF);
3231}
3232
3233namespace {
3234
3235// Keep track the alignment, constpool entries per Section.
3236 struct SectionCPs {
3237 MCSection *S;
3238 Align Alignment;
3239 SmallVector<unsigned, 4> CPEs;
3240
3241 SectionCPs(MCSection *s, Align a) : S(s), Alignment(a) {}
3242 };
3243
3244} // end anonymous namespace
3245
3246StringRef AsmPrinter::getConstantSectionSuffix(const Constant *C) const {
3247 if (TM.Options.EnableStaticDataPartitioning && C && SDPI && PSI)
3248 return SDPI->getConstantSectionPrefix(C, PSI);
3249
3250 return "";
3251}
3252
3253/// EmitConstantPool - Print to the current output stream assembly
3254/// representations of the constants in the constant pool MCP. This is
3255/// used to print out constants which have been "spilled to memory" by
3256/// the code generator.
3257void AsmPrinter::emitConstantPool() {
3258 const MachineConstantPool *MCP = MF->getConstantPool();
3259 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
3260 if (CP.empty()) return;
3261
3262 // Calculate sections for constant pool entries. We collect entries to go into
3263 // the same section together to reduce amount of section switch statements.
3264 SmallVector<SectionCPs, 4> CPSections;
3265 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
3266 const MachineConstantPoolEntry &CPE = CP[i];
3267 Align Alignment = CPE.getAlign();
3268
3269 SectionKind Kind = CPE.getSectionKind(DL: &getDataLayout());
3270
3271 const Constant *C = nullptr;
3272 if (!CPE.isMachineConstantPoolEntry())
3273 C = CPE.Val.ConstVal;
3274
3275 MCSection *S = getObjFileLowering().getSectionForConstant(
3276 DL: getDataLayout(), Kind, C, Alignment, F: &MF->getFunction(),
3277 SectionSuffix: getConstantSectionSuffix(C));
3278
3279 // The number of sections are small, just do a linear search from the
3280 // last section to the first.
3281 bool Found = false;
3282 unsigned SecIdx = CPSections.size();
3283 while (SecIdx != 0) {
3284 if (CPSections[--SecIdx].S == S) {
3285 Found = true;
3286 break;
3287 }
3288 }
3289 if (!Found) {
3290 SecIdx = CPSections.size();
3291 CPSections.push_back(Elt: SectionCPs(S, Alignment));
3292 }
3293
3294 if (Alignment > CPSections[SecIdx].Alignment)
3295 CPSections[SecIdx].Alignment = Alignment;
3296 CPSections[SecIdx].CPEs.push_back(Elt: i);
3297 }
3298
3299 // Now print stuff into the calculated sections.
3300 const MCSection *CurSection = nullptr;
3301 unsigned Offset = 0;
3302 for (const SectionCPs &CPSection : CPSections) {
3303 for (unsigned CPI : CPSection.CPEs) {
3304 MCSymbol *Sym = GetCPISymbol(CPID: CPI);
3305 if (!Sym->isUndefined())
3306 continue;
3307
3308 if (CurSection != CPSection.S) {
3309 OutStreamer->switchSection(Section: CPSection.S);
3310 emitAlignment(Alignment: Align(CPSection.Alignment));
3311 CurSection = CPSection.S;
3312 Offset = 0;
3313 }
3314
3315 MachineConstantPoolEntry CPE = CP[CPI];
3316
3317 // Emit inter-object padding for alignment.
3318 unsigned NewOffset = alignTo(Size: Offset, A: CPE.getAlign());
3319 OutStreamer->emitZeros(NumBytes: NewOffset - Offset);
3320
3321 Offset = NewOffset + CPE.getSizeInBytes(DL: getDataLayout());
3322
3323 OutStreamer->emitLabel(Symbol: Sym);
3324 if (CPE.isMachineConstantPoolEntry())
3325 emitMachineConstantPoolValue(MCPV: CPE.Val.MachineCPVal);
3326 else
3327 emitGlobalConstant(DL: getDataLayout(), CV: CPE.Val.ConstVal);
3328 }
3329 }
3330}
3331
3332// Print assembly representations of the jump tables used by the current
3333// function.
3334void AsmPrinter::emitJumpTableInfo() {
3335 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
3336 if (!MJTI) return;
3337
3338 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
3339 if (JT.empty()) return;
3340
3341 if (!TM.Options.EnableStaticDataPartitioning) {
3342 emitJumpTableImpl(MJTI: *MJTI, JumpTableIndices: llvm::to_vector(Range: llvm::seq<unsigned>(Size: JT.size())));
3343 return;
3344 }
3345
3346 SmallVector<unsigned> HotJumpTableIndices, ColdJumpTableIndices;
3347 // When static data partitioning is enabled, collect jump table entries that
3348 // go into the same section together to reduce the amount of section switch
3349 // statements.
3350 for (unsigned JTI = 0, JTSize = JT.size(); JTI < JTSize; ++JTI) {
3351 if (JT[JTI].Hotness == MachineFunctionDataHotness::Cold) {
3352 ColdJumpTableIndices.push_back(Elt: JTI);
3353 } else {
3354 HotJumpTableIndices.push_back(Elt: JTI);
3355 }
3356 }
3357
3358 emitJumpTableImpl(MJTI: *MJTI, JumpTableIndices: HotJumpTableIndices);
3359 emitJumpTableImpl(MJTI: *MJTI, JumpTableIndices: ColdJumpTableIndices);
3360}
3361
3362void AsmPrinter::emitJumpTableImpl(const MachineJumpTableInfo &MJTI,
3363 ArrayRef<unsigned> JumpTableIndices) {
3364 if (MJTI.getEntryKind() == MachineJumpTableInfo::EK_Inline ||
3365 JumpTableIndices.empty())
3366 return;
3367
3368 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
3369 const Function &F = MF->getFunction();
3370 const std::vector<MachineJumpTableEntry> &JT = MJTI.getJumpTables();
3371 MCSection *JumpTableSection = nullptr;
3372
3373 const bool UseLabelDifference =
3374 MJTI.getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
3375 MJTI.getEntryKind() == MachineJumpTableInfo::EK_LabelDifference64;
3376 // Pick the directive to use to print the jump table entries, and switch to
3377 // the appropriate section.
3378 const bool JTInDiffSection =
3379 !TLOF.shouldPutJumpTableInFunctionSection(UsesLabelDifference: UseLabelDifference, F);
3380 if (JTInDiffSection) {
3381 if (TM.Options.EnableStaticDataPartitioning) {
3382 JumpTableSection =
3383 TLOF.getSectionForJumpTable(F, TM, JTE: &JT[JumpTableIndices.front()]);
3384 } else {
3385 JumpTableSection = TLOF.getSectionForJumpTable(F, TM);
3386 }
3387 OutStreamer->switchSection(Section: JumpTableSection);
3388 }
3389
3390 const DataLayout &DL = MF->getDataLayout();
3391 emitAlignment(Alignment: Align(MJTI.getEntryAlignment(TD: DL)));
3392
3393 // Jump tables in code sections are marked with a data_region directive
3394 // where that's supported.
3395 if (!JTInDiffSection)
3396 OutStreamer->emitDataRegion(Kind: MCDR_DataRegionJT32);
3397
3398 for (const unsigned JumpTableIndex : JumpTableIndices) {
3399 ArrayRef<MachineBasicBlock *> JTBBs = JT[JumpTableIndex].MBBs;
3400
3401 // If this jump table was deleted, ignore it.
3402 if (JTBBs.empty())
3403 continue;
3404
3405 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
3406 /// emit a .set directive for each unique entry.
3407 if (MJTI.getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
3408 MAI.doesSetDirectiveSuppressReloc()) {
3409 SmallPtrSet<const MachineBasicBlock *, 16> EmittedSets;
3410 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
3411 const MCExpr *Base =
3412 TLI->getPICJumpTableRelocBaseExpr(MF, JTI: JumpTableIndex, Ctx&: OutContext);
3413 for (const MachineBasicBlock *MBB : JTBBs) {
3414 if (!EmittedSets.insert(Ptr: MBB).second)
3415 continue;
3416
3417 // .set LJTSet, LBB32-base
3418 const MCExpr *LHS =
3419 MCSymbolRefExpr::create(Symbol: MBB->getSymbol(), Ctx&: OutContext);
3420 OutStreamer->emitAssignment(
3421 Symbol: GetJTSetSymbol(UID: JumpTableIndex, MBBID: MBB->getNumber()),
3422 Value: MCBinaryExpr::createSub(LHS, RHS: Base, Ctx&: OutContext));
3423 }
3424 }
3425
3426 // On some targets (e.g. Darwin) we want to emit two consecutive labels
3427 // before each jump table. The first label is never referenced, but tells
3428 // the assembler and linker the extents of the jump table object. The
3429 // second label is actually referenced by the code.
3430 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
3431 // FIXME: This doesn't have to have any specific name, just any randomly
3432 // named and numbered local label started with 'l' would work. Simplify
3433 // GetJTISymbol.
3434 OutStreamer->emitLabel(Symbol: GetJTISymbol(JTID: JumpTableIndex, isLinkerPrivate: true));
3435
3436 MCSymbol *JTISymbol = GetJTISymbol(JTID: JumpTableIndex);
3437 OutStreamer->emitLabel(Symbol: JTISymbol);
3438
3439 // Defer MCAssembler based constant folding due to a performance issue. The
3440 // label differences will be evaluated at write time.
3441 for (const MachineBasicBlock *MBB : JTBBs)
3442 emitJumpTableEntry(MJTI, MBB, uid: JumpTableIndex);
3443 }
3444
3445 if (EmitJumpTableSizesSection)
3446 emitJumpTableSizesSection(MJTI, F: MF->getFunction());
3447
3448 if (!JTInDiffSection)
3449 OutStreamer->emitDataRegion(Kind: MCDR_DataRegionEnd);
3450}
3451
3452void AsmPrinter::emitJumpTableSizesSection(const MachineJumpTableInfo &MJTI,
3453 const Function &F) const {
3454 const std::vector<MachineJumpTableEntry> &JT = MJTI.getJumpTables();
3455
3456 if (JT.empty())
3457 return;
3458
3459 StringRef GroupName = F.hasComdat() ? F.getComdat()->getName() : "";
3460 MCSection *JumpTableSizesSection = nullptr;
3461 StringRef sectionName = ".llvm_jump_table_sizes";
3462
3463 bool isElf = TM.getTargetTriple().isOSBinFormatELF();
3464 bool isCoff = TM.getTargetTriple().isOSBinFormatCOFF();
3465
3466 if (!isCoff && !isElf)
3467 return;
3468
3469 if (isElf) {
3470 auto *LinkedToSym = static_cast<MCSymbolELF *>(CurrentFnSym);
3471 int Flags = F.hasComdat() ? static_cast<int>(ELF::SHF_GROUP) : 0;
3472
3473 JumpTableSizesSection = OutContext.getELFSection(
3474 Section: sectionName, Type: ELF::SHT_LLVM_JT_SIZES, Flags, EntrySize: 0, Group: GroupName, IsComdat: F.hasComdat(),
3475 UniqueID: MCSection::NonUniqueID, LinkedToSym);
3476 } else if (isCoff) {
3477 if (F.hasComdat()) {
3478 JumpTableSizesSection = OutContext.getCOFFSection(
3479 Section: sectionName,
3480 Characteristics: COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
3481 COFF::IMAGE_SCN_LNK_COMDAT | COFF::IMAGE_SCN_MEM_DISCARDABLE,
3482 COMDATSymName: F.getComdat()->getName(), Selection: COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE);
3483 } else {
3484 JumpTableSizesSection = OutContext.getCOFFSection(
3485 Section: sectionName, Characteristics: COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
3486 COFF::IMAGE_SCN_MEM_READ |
3487 COFF::IMAGE_SCN_MEM_DISCARDABLE);
3488 }
3489 }
3490
3491 OutStreamer->switchSection(Section: JumpTableSizesSection);
3492
3493 for (unsigned JTI = 0, E = JT.size(); JTI != E; ++JTI) {
3494 const std::vector<MachineBasicBlock *> &JTBBs = JT[JTI].MBBs;
3495 OutStreamer->emitSymbolValue(Sym: GetJTISymbol(JTID: JTI), Size: TM.getProgramPointerSize());
3496 OutStreamer->emitIntValue(Value: JTBBs.size(), Size: TM.getProgramPointerSize());
3497 }
3498}
3499
3500/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
3501/// current stream.
3502void AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo &MJTI,
3503 const MachineBasicBlock *MBB,
3504 unsigned UID) const {
3505 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
3506 const MCExpr *Value = nullptr;
3507 switch (MJTI.getEntryKind()) {
3508 case MachineJumpTableInfo::EK_Inline:
3509 llvm_unreachable("Cannot emit EK_Inline jump table entry");
3510 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
3511 case MachineJumpTableInfo::EK_GPRel64BlockAddress:
3512 llvm_unreachable("MIPS specific");
3513 case MachineJumpTableInfo::EK_Custom32:
3514 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
3515 &MJTI, MBB, UID, OutContext);
3516 break;
3517 case MachineJumpTableInfo::EK_BlockAddress:
3518 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
3519 // .word LBB123
3520 Value = MCSymbolRefExpr::create(Symbol: MBB->getSymbol(), Ctx&: OutContext);
3521 break;
3522
3523 case MachineJumpTableInfo::EK_LabelDifference32:
3524 case MachineJumpTableInfo::EK_LabelDifference64: {
3525 // Each entry is the address of the block minus the address of the jump
3526 // table. This is used for PIC jump tables where gprel32 is not supported.
3527 // e.g.:
3528 // .word LBB123 - LJTI1_2
3529 // If the .set directive avoids relocations, this is emitted as:
3530 // .set L4_5_set_123, LBB123 - LJTI1_2
3531 // .word L4_5_set_123
3532 if (MJTI.getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
3533 MAI.doesSetDirectiveSuppressReloc()) {
3534 Value = MCSymbolRefExpr::create(Symbol: GetJTSetSymbol(UID, MBBID: MBB->getNumber()),
3535 Ctx&: OutContext);
3536 break;
3537 }
3538 Value = MCSymbolRefExpr::create(Symbol: MBB->getSymbol(), Ctx&: OutContext);
3539 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
3540 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, JTI: UID, Ctx&: OutContext);
3541 Value = MCBinaryExpr::createSub(LHS: Value, RHS: Base, Ctx&: OutContext);
3542 break;
3543 }
3544 }
3545
3546 assert(Value && "Unknown entry kind!");
3547
3548 unsigned EntrySize = MJTI.getEntrySize(TD: getDataLayout());
3549 OutStreamer->emitValue(Value, Size: EntrySize);
3550}
3551
3552/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
3553/// special global used by LLVM. If so, emit it and return true, otherwise
3554/// do nothing and return false.
3555bool AsmPrinter::emitSpecialLLVMGlobal(const GlobalVariable *GV) {
3556 if (GV->getName() == "llvm.used") {
3557 if (MAI.hasNoDeadStrip()) // No need to emit this at all.
3558 emitLLVMUsedList(InitList: cast<ConstantArray>(Val: GV->getInitializer()));
3559 return true;
3560 }
3561
3562 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
3563 if (GV->getSection() == "llvm.metadata" ||
3564 GV->hasAvailableExternallyLinkage())
3565 return true;
3566
3567 if (GV->getName() == "llvm.arm64ec.symbolmap") {
3568 // For ARM64EC, print the table that maps between symbols and the
3569 // corresponding thunks to translate between x64 and AArch64 code.
3570 // This table is generated by AArch64Arm64ECCallLowering.
3571 OutStreamer->switchSection(
3572 Section: OutContext.getCOFFSection(Section: ".hybmp$x", Characteristics: COFF::IMAGE_SCN_LNK_INFO));
3573 auto *Arr = cast<ConstantArray>(Val: GV->getInitializer());
3574 for (auto &U : Arr->operands()) {
3575 auto *C = cast<Constant>(Val: U);
3576 auto *Src = cast<GlobalValue>(Val: C->getOperand(i: 0)->stripPointerCasts());
3577 auto *Dst = cast<GlobalValue>(Val: C->getOperand(i: 1)->stripPointerCasts());
3578 int Kind = cast<ConstantInt>(Val: C->getOperand(i: 2))->getZExtValue();
3579
3580 if (Src->hasDLLImportStorageClass()) {
3581 // For now, we assume dllimport functions aren't directly called.
3582 // (We might change this later to match MSVC.)
3583 OutStreamer->emitCOFFSymbolIndex(
3584 Symbol: OutContext.getOrCreateSymbol(Name: "__imp_" + Src->getName()));
3585 OutStreamer->emitCOFFSymbolIndex(Symbol: getSymbol(GV: Dst));
3586 OutStreamer->emitInt32(Value: Kind);
3587 } else {
3588 // FIXME: For non-dllimport functions, MSVC emits the same entry
3589 // twice, for reasons I don't understand. I have to assume the linker
3590 // ignores the redundant entry; there aren't any reasonable semantics
3591 // to attach to it.
3592 OutStreamer->emitCOFFSymbolIndex(Symbol: getSymbol(GV: Src));
3593 OutStreamer->emitCOFFSymbolIndex(Symbol: getSymbol(GV: Dst));
3594 OutStreamer->emitInt32(Value: Kind);
3595 }
3596 }
3597 return true;
3598 }
3599
3600 if (!GV->hasAppendingLinkage()) return false;
3601
3602 assert(GV->hasInitializer() && "Not a special LLVM global!");
3603
3604 if (GV->getName() == "llvm.global_ctors") {
3605 emitXXStructorList(DL: GV->getDataLayout(), List: GV->getInitializer(),
3606 /* isCtor */ IsCtor: true);
3607
3608 return true;
3609 }
3610
3611 if (GV->getName() == "llvm.global_dtors") {
3612 emitXXStructorList(DL: GV->getDataLayout(), List: GV->getInitializer(),
3613 /* isCtor */ IsCtor: false);
3614
3615 return true;
3616 }
3617
3618 GV->getContext().emitError(
3619 ErrorStr: "unknown special variable with appending linkage: " +
3620 GV->getNameOrAsOperand());
3621 return true;
3622}
3623
3624/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
3625/// global in the specified llvm.used list.
3626void AsmPrinter::emitLLVMUsedList(const ConstantArray *InitList) {
3627 // Should be an array of 'i8*'.
3628 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
3629 const GlobalValue *GV =
3630 dyn_cast<GlobalValue>(Val: InitList->getOperand(i_nocapture: i)->stripPointerCasts());
3631 if (GV)
3632 OutStreamer->emitSymbolAttribute(Symbol: getSymbol(GV), Attribute: MCSA_NoDeadStrip);
3633 }
3634}
3635
3636void AsmPrinter::preprocessXXStructorList(const DataLayout &DL,
3637 const Constant *List,
3638 SmallVector<Structor, 8> &Structors) {
3639 // Should be an array of '{ i32, void ()*, i8* }' structs. The first value is
3640 // the init priority.
3641 if (!isa<ConstantArray>(Val: List))
3642 return;
3643
3644 // Gather the structors in a form that's convenient for sorting by priority.
3645 for (Value *O : cast<ConstantArray>(Val: List)->operands()) {
3646 auto *CS = cast<ConstantStruct>(Val: O);
3647 if (CS->getOperand(i_nocapture: 1)->isNullValue())
3648 break; // Found a null terminator, skip the rest.
3649 ConstantInt *Priority = dyn_cast<ConstantInt>(Val: CS->getOperand(i_nocapture: 0));
3650 if (!Priority)
3651 continue; // Malformed.
3652 Structors.push_back(Elt: Structor());
3653 Structor &S = Structors.back();
3654 S.Priority = Priority->getLimitedValue(Limit: 65535);
3655 S.Func = CS->getOperand(i_nocapture: 1);
3656 if (!CS->getOperand(i_nocapture: 2)->isNullValue()) {
3657 if (TM.getTargetTriple().isOSAIX()) {
3658 CS->getContext().emitError(
3659 ErrorStr: "associated data of XXStructor list is not yet supported on AIX");
3660 }
3661
3662 S.ComdatKey =
3663 dyn_cast<GlobalValue>(Val: CS->getOperand(i_nocapture: 2)->stripPointerCasts());
3664 }
3665 }
3666
3667 // Emit the function pointers in the target-specific order
3668 llvm::stable_sort(Range&: Structors, C: [](const Structor &L, const Structor &R) {
3669 return L.Priority < R.Priority;
3670 });
3671}
3672
3673/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
3674/// priority.
3675void AsmPrinter::emitXXStructorList(const DataLayout &DL, const Constant *List,
3676 bool IsCtor) {
3677 SmallVector<Structor, 8> Structors;
3678 preprocessXXStructorList(DL, List, Structors);
3679 if (Structors.empty())
3680 return;
3681
3682 // Emit the structors in reverse order if we are using the .ctor/.dtor
3683 // initialization scheme.
3684 if (!TM.Options.UseInitArray)
3685 std::reverse(first: Structors.begin(), last: Structors.end());
3686
3687 const Align Align = DL.getPointerPrefAlignment(AS: DL.getProgramAddressSpace());
3688 for (Structor &S : Structors) {
3689 const TargetLoweringObjectFile &Obj = getObjFileLowering();
3690 const MCSymbol *KeySym = nullptr;
3691 if (GlobalValue *GV = S.ComdatKey) {
3692 if (GV->isDeclarationForLinker())
3693 // If the associated variable is not defined in this module
3694 // (it might be available_externally, or have been an
3695 // available_externally definition that was dropped by the
3696 // EliminateAvailableExternally pass), some other TU
3697 // will provide its dynamic initializer.
3698 continue;
3699
3700 KeySym = getSymbol(GV);
3701 }
3702
3703 MCSection *OutputSection =
3704 (IsCtor ? Obj.getStaticCtorSection(Priority: S.Priority, KeySym)
3705 : Obj.getStaticDtorSection(Priority: S.Priority, KeySym));
3706 OutStreamer->switchSection(Section: OutputSection);
3707 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
3708 emitAlignment(Alignment: Align);
3709 emitXXStructor(DL, CV: S.Func);
3710 }
3711}
3712
3713void AsmPrinter::emitModuleIdents(Module &M) {
3714 if (!MAI.hasIdentDirective())
3715 return;
3716
3717 if (const NamedMDNode *NMD = M.getNamedMetadata(Name: "llvm.ident")) {
3718 for (const MDNode *N : NMD->operands()) {
3719 assert(N->getNumOperands() == 1 &&
3720 "llvm.ident metadata entry can have only one operand");
3721 const MDString *S = cast<MDString>(Val: N->getOperand(I: 0));
3722 OutStreamer->emitIdent(IdentString: S->getString());
3723 }
3724 }
3725}
3726
3727void AsmPrinter::emitModuleCommandLines(Module &M) {
3728 MCSection *CommandLine = getObjFileLowering().getSectionForCommandLines();
3729 if (!CommandLine)
3730 return;
3731
3732 const NamedMDNode *NMD = M.getNamedMetadata(Name: "llvm.commandline");
3733 if (!NMD || !NMD->getNumOperands())
3734 return;
3735
3736 OutStreamer->pushSection();
3737 OutStreamer->switchSection(Section: CommandLine);
3738 OutStreamer->emitZeros(NumBytes: 1);
3739 for (const MDNode *N : NMD->operands()) {
3740 assert(N->getNumOperands() == 1 &&
3741 "llvm.commandline metadata entry can have only one operand");
3742 const MDString *S = cast<MDString>(Val: N->getOperand(I: 0));
3743 OutStreamer->emitBytes(Data: S->getString());
3744 OutStreamer->emitZeros(NumBytes: 1);
3745 }
3746 OutStreamer->popSection();
3747}
3748
3749//===--------------------------------------------------------------------===//
3750// Emission and print routines
3751//
3752
3753/// Emit a byte directive and value.
3754///
3755void AsmPrinter::emitInt8(int Value) const { OutStreamer->emitInt8(Value); }
3756
3757/// Emit a short directive and value.
3758void AsmPrinter::emitInt16(int Value) const { OutStreamer->emitInt16(Value); }
3759
3760/// Emit a long directive and value.
3761void AsmPrinter::emitInt32(int Value) const { OutStreamer->emitInt32(Value); }
3762
3763/// EmitSLEB128 - emit the specified signed leb128 value.
3764void AsmPrinter::emitSLEB128(int64_t Value, const char *Desc) const {
3765 if (isVerbose() && Desc)
3766 OutStreamer->AddComment(T: Desc);
3767
3768 OutStreamer->emitSLEB128IntValue(Value);
3769}
3770
3771void AsmPrinter::emitULEB128(uint64_t Value, const char *Desc,
3772 unsigned PadTo) const {
3773 if (isVerbose() && Desc)
3774 OutStreamer->AddComment(T: Desc);
3775
3776 OutStreamer->emitULEB128IntValue(Value, PadTo);
3777}
3778
3779/// Emit a long long directive and value.
3780void AsmPrinter::emitInt64(uint64_t Value) const {
3781 OutStreamer->emitInt64(Value);
3782}
3783
3784/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
3785/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
3786/// .set if it avoids relocations.
3787void AsmPrinter::emitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
3788 unsigned Size) const {
3789 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
3790}
3791
3792/// Emit something like ".uleb128 Hi-Lo".
3793void AsmPrinter::emitLabelDifferenceAsULEB128(const MCSymbol *Hi,
3794 const MCSymbol *Lo) const {
3795 OutStreamer->emitAbsoluteSymbolDiffAsULEB128(Hi, Lo);
3796}
3797
3798/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
3799/// where the size in bytes of the directive is specified by Size and Label
3800/// specifies the label. This implicitly uses .set if it is available.
3801void AsmPrinter::emitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
3802 unsigned Size,
3803 bool IsSectionRelative) const {
3804 if (MAI.needsDwarfSectionOffsetDirective() && IsSectionRelative) {
3805 OutStreamer->emitCOFFSecRel32(Symbol: Label, Offset);
3806 if (Size > 4)
3807 OutStreamer->emitZeros(NumBytes: Size - 4);
3808 return;
3809 }
3810
3811 // Emit Label+Offset (or just Label if Offset is zero)
3812 const MCExpr *Expr = MCSymbolRefExpr::create(Symbol: Label, Ctx&: OutContext);
3813 if (Offset)
3814 Expr = MCBinaryExpr::createAdd(
3815 LHS: Expr, RHS: MCConstantExpr::create(Value: Offset, Ctx&: OutContext), Ctx&: OutContext);
3816
3817 OutStreamer->emitValue(Value: Expr, Size);
3818}
3819
3820//===----------------------------------------------------------------------===//
3821
3822// EmitAlignment - Emit an alignment directive to the specified power of
3823// two boundary. If a global value is specified, and if that global has
3824// an explicit alignment requested, it will override the alignment request
3825// if required for correctness.
3826Align AsmPrinter::emitAlignment(Align Alignment, const GlobalObject *GV,
3827 unsigned MaxBytesToEmit) const {
3828 if (GV)
3829 Alignment = getGVAlignment(GV, DL: GV->getDataLayout(), InAlign: Alignment);
3830
3831 if (Alignment == Align(1))
3832 return Alignment; // 1-byte aligned: no need to emit alignment.
3833
3834 if (getCurrentSection()->isText()) {
3835 const MCSubtargetInfo *STI = nullptr;
3836 if (this->MF)
3837 STI = &getSubtargetInfo();
3838 else
3839 STI = &TM.getMCSubtargetInfo();
3840 OutStreamer->emitCodeAlignment(Alignment, STI: *STI, MaxBytesToEmit);
3841 } else
3842 OutStreamer->emitValueToAlignment(Alignment, Fill: 0, FillLen: 1, MaxBytesToEmit);
3843 return Alignment;
3844}
3845
3846//===----------------------------------------------------------------------===//
3847// Constant emission.
3848//===----------------------------------------------------------------------===//
3849
3850const MCExpr *AsmPrinter::lowerConstant(const Constant *CV,
3851 const Constant *BaseCV,
3852 uint64_t Offset) {
3853 MCContext &Ctx = OutContext;
3854
3855 if (CV->isNullValue() || isa<UndefValue>(Val: CV))
3856 return MCConstantExpr::create(Value: 0, Ctx);
3857
3858 if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val: CV))
3859 return MCConstantExpr::create(Value: CI->getZExtValue(), Ctx);
3860
3861 if (const ConstantByte *CB = dyn_cast<ConstantByte>(Val: CV))
3862 return MCConstantExpr::create(Value: CB->getZExtValue(), Ctx);
3863
3864 if (const ConstantPtrAuth *CPA = dyn_cast<ConstantPtrAuth>(Val: CV))
3865 return lowerConstantPtrAuth(CPA: *CPA);
3866
3867 if (const GlobalValue *GV = dyn_cast<GlobalValue>(Val: CV))
3868 return MCSymbolRefExpr::create(Symbol: getSymbol(GV), Ctx);
3869
3870 if (const BlockAddress *BA = dyn_cast<BlockAddress>(Val: CV))
3871 return lowerBlockAddressConstant(BA: *BA);
3872
3873 if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(Val: CV))
3874 return getObjFileLowering().lowerDSOLocalEquivalent(
3875 LHS: getSymbol(GV: Equiv->getGlobalValue()), RHS: nullptr, Addend: 0, PCRelativeOffset: std::nullopt, TM);
3876
3877 if (const NoCFIValue *NC = dyn_cast<NoCFIValue>(Val: CV))
3878 return MCSymbolRefExpr::create(Symbol: getSymbol(GV: NC->getGlobalValue()), Ctx);
3879
3880 const ConstantExpr *CE = dyn_cast<ConstantExpr>(Val: CV);
3881 if (!CE) {
3882 llvm_unreachable("Unknown constant value to lower!");
3883 }
3884
3885 // The constant expression opcodes are limited to those that are necessary
3886 // to represent relocations on supported targets. Expressions involving only
3887 // constant addresses are constant folded instead.
3888 switch (CE->getOpcode()) {
3889 default:
3890 break; // Error
3891 case Instruction::AddrSpaceCast: {
3892 const Constant *Op = CE->getOperand(i_nocapture: 0);
3893 unsigned DstAS = CE->getType()->getPointerAddressSpace();
3894 unsigned SrcAS = Op->getType()->getPointerAddressSpace();
3895 if (TM.isNoopAddrSpaceCast(SrcAS, DestAS: DstAS))
3896 return lowerConstant(CV: Op);
3897
3898 break; // Error
3899 }
3900 case Instruction::GetElementPtr: {
3901 // Generate a symbolic expression for the byte address
3902 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
3903 cast<GEPOperator>(Val: CE)->accumulateConstantOffset(DL: getDataLayout(), Offset&: OffsetAI);
3904
3905 const MCExpr *Base = lowerConstant(CV: CE->getOperand(i_nocapture: 0));
3906 if (!OffsetAI)
3907 return Base;
3908
3909 int64_t Offset = OffsetAI.getSExtValue();
3910 return MCBinaryExpr::createAdd(LHS: Base, RHS: MCConstantExpr::create(Value: Offset, Ctx),
3911 Ctx);
3912 }
3913
3914 case Instruction::Trunc:
3915 // We emit the value and depend on the assembler to truncate the generated
3916 // expression properly. This is important for differences between
3917 // blockaddress labels. Since the two labels are in the same function, it
3918 // is reasonable to treat their delta as a 32-bit value.
3919 [[fallthrough]];
3920 case Instruction::BitCast:
3921 return lowerConstant(CV: CE->getOperand(i_nocapture: 0), BaseCV, Offset);
3922
3923 case Instruction::IntToPtr: {
3924 const DataLayout &DL = getDataLayout();
3925
3926 // Handle casts to pointers by changing them into casts to the appropriate
3927 // integer type. This promotes constant folding and simplifies this code.
3928 Constant *Op = CE->getOperand(i_nocapture: 0);
3929 Op = ConstantFoldIntegerCast(C: Op, DestTy: DL.getIntPtrType(CV->getType()),
3930 /*IsSigned*/ false, DL);
3931 if (Op)
3932 return lowerConstant(CV: Op);
3933
3934 break; // Error
3935 }
3936
3937 case Instruction::PtrToAddr:
3938 case Instruction::PtrToInt: {
3939 const DataLayout &DL = getDataLayout();
3940
3941 // Support only foldable casts to/from pointers that can be eliminated by
3942 // changing the pointer to the appropriately sized integer type.
3943 Constant *Op = CE->getOperand(i_nocapture: 0);
3944 Type *Ty = CE->getType();
3945
3946 const MCExpr *OpExpr = lowerConstant(CV: Op);
3947
3948 // We can emit the pointer value into this slot if the slot is an
3949 // integer slot equal to the size of the pointer.
3950 //
3951 // If the pointer is larger than the resultant integer, then
3952 // as with Trunc just depend on the assembler to truncate it.
3953 if (DL.getTypeAllocSize(Ty).getFixedValue() <=
3954 DL.getTypeAllocSize(Ty: Op->getType()).getFixedValue())
3955 return OpExpr;
3956
3957 break; // Error
3958 }
3959
3960 case Instruction::Sub: {
3961 GlobalValue *LHSGV, *RHSGV;
3962 APInt LHSOffset, RHSOffset;
3963 DSOLocalEquivalent *DSOEquiv;
3964 if (IsConstantOffsetFromGlobal(C: CE->getOperand(i_nocapture: 0), GV&: LHSGV, Offset&: LHSOffset,
3965 DL: getDataLayout(), DSOEquiv: &DSOEquiv) &&
3966 IsConstantOffsetFromGlobal(C: CE->getOperand(i_nocapture: 1), GV&: RHSGV, Offset&: RHSOffset,
3967 DL: getDataLayout())) {
3968 auto *LHSSym = getSymbol(GV: LHSGV);
3969 auto *RHSSym = getSymbol(GV: RHSGV);
3970 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
3971 std::optional<int64_t> PCRelativeOffset;
3972 if (getObjFileLowering().hasPLTPCRelative() && RHSGV == BaseCV)
3973 PCRelativeOffset = Offset;
3974
3975 // Try the generic symbol difference first.
3976 const MCExpr *Res = getObjFileLowering().lowerRelativeReference(
3977 LHS: LHSGV, RHS: RHSGV, Addend, PCRelativeOffset, TM);
3978
3979 // (ELF-specific) If the generic symbol difference does not apply, and
3980 // LHS is a dso_local_equivalent of a function, reference the PLT entry
3981 // instead. Note: A default visibility symbol is by default preemptible
3982 // during linking, and should not be referenced with PC-relative
3983 // relocations. Therefore, use a PLT relocation even if the function is
3984 // dso_local.
3985 if (DSOEquiv && TM.getTargetTriple().isOSBinFormatELF())
3986 Res = getObjFileLowering().lowerDSOLocalEquivalent(
3987 LHS: LHSSym, RHS: RHSSym, Addend, PCRelativeOffset, TM);
3988
3989 // Otherwise, return LHS-RHS+Addend.
3990 if (!Res) {
3991 Res =
3992 MCBinaryExpr::createSub(LHS: MCSymbolRefExpr::create(Symbol: LHSSym, Ctx),
3993 RHS: MCSymbolRefExpr::create(Symbol: RHSSym, Ctx), Ctx);
3994 if (Addend != 0)
3995 Res = MCBinaryExpr::createAdd(
3996 LHS: Res, RHS: MCConstantExpr::create(Value: Addend, Ctx), Ctx);
3997 }
3998 return Res;
3999 }
4000
4001 const MCExpr *LHS = lowerConstant(CV: CE->getOperand(i_nocapture: 0));
4002 const MCExpr *RHS = lowerConstant(CV: CE->getOperand(i_nocapture: 1));
4003 return MCBinaryExpr::createSub(LHS, RHS, Ctx);
4004 break;
4005 }
4006
4007 case Instruction::Add: {
4008 const MCExpr *LHS = lowerConstant(CV: CE->getOperand(i_nocapture: 0));
4009 const MCExpr *RHS = lowerConstant(CV: CE->getOperand(i_nocapture: 1));
4010 return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
4011 }
4012 }
4013
4014 // If the code isn't optimized, there may be outstanding folding
4015 // opportunities. Attempt to fold the expression using DataLayout as a
4016 // last resort before giving up.
4017 Constant *C = ConstantFoldConstant(C: CE, DL: getDataLayout());
4018 if (C != CE)
4019 return lowerConstant(CV: C);
4020
4021 // Otherwise report the problem to the user.
4022 std::string S;
4023 raw_string_ostream OS(S);
4024 OS << "unsupported expression in static initializer: ";
4025 CE->printAsOperand(O&: OS, /*PrintType=*/false,
4026 M: !MF ? nullptr : MF->getFunction().getParent());
4027 CE->getContext().emitError(ErrorStr: S);
4028 return MCConstantExpr::create(Value: 0, Ctx);
4029}
4030
4031static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
4032 AsmPrinter &AP,
4033 const Constant *BaseCV = nullptr,
4034 uint64_t Offset = 0,
4035 AsmPrinter::AliasMapTy *AliasList = nullptr);
4036
4037static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
4038static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP);
4039
4040/// isRepeatedByteSequence - Determine whether the given value is
4041/// composed of a repeated sequence of identical bytes and return the
4042/// byte value. If it is not a repeated sequence, return -1.
4043static int isRepeatedByteSequence(const ConstantDataSequential *V) {
4044 StringRef Data = V->getRawDataValues();
4045 assert(!Data.empty() && "Empty aggregates should be CAZ node");
4046 char C = Data[0];
4047 for (unsigned i = 1, e = Data.size(); i != e; ++i)
4048 if (Data[i] != C) return -1;
4049 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
4050}
4051
4052/// isRepeatedByteSequence - Determine whether the given value is
4053/// composed of a repeated sequence of identical bytes and return the
4054/// byte value. If it is not a repeated sequence, return -1.
4055static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
4056 if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val: V)) {
4057 uint64_t Size = DL.getTypeAllocSizeInBits(Ty: V->getType());
4058 assert(Size % 8 == 0);
4059
4060 // Extend the element to take zero padding into account.
4061 APInt Value = CI->getValue().zext(width: Size);
4062 if (!Value.isSplat(SplatSizeInBits: 8))
4063 return -1;
4064
4065 return Value.zextOrTrunc(width: 8).getZExtValue();
4066 }
4067 if (const ConstantArray *CA = dyn_cast<ConstantArray>(Val: V)) {
4068 // Make sure all array elements are sequences of the same repeated
4069 // byte.
4070 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
4071 Constant *Op0 = CA->getOperand(i_nocapture: 0);
4072 int Byte = isRepeatedByteSequence(V: Op0, DL);
4073 if (Byte == -1)
4074 return -1;
4075
4076 // All array elements must be equal.
4077 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
4078 if (CA->getOperand(i_nocapture: i) != Op0)
4079 return -1;
4080 return Byte;
4081 }
4082
4083 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(Val: V))
4084 return isRepeatedByteSequence(V: CDS);
4085
4086 return -1;
4087}
4088
4089static void emitGlobalAliasInline(AsmPrinter &AP, uint64_t Offset,
4090 AsmPrinter::AliasMapTy *AliasList) {
4091 if (AliasList) {
4092 auto AliasIt = AliasList->find(Val: Offset);
4093 if (AliasIt != AliasList->end()) {
4094 for (const GlobalAlias *GA : AliasIt->second)
4095 AP.OutStreamer->emitLabel(Symbol: AP.getSymbol(GV: GA));
4096 AliasList->erase(Val: Offset);
4097 }
4098 }
4099}
4100
4101static void emitGlobalConstantDataSequential(
4102 const DataLayout &DL, const ConstantDataSequential *CDS, AsmPrinter &AP,
4103 AsmPrinter::AliasMapTy *AliasList) {
4104 // See if we can aggregate this into a .fill, if so, emit it as such.
4105 int Value = isRepeatedByteSequence(V: CDS, DL);
4106 if (Value != -1) {
4107 uint64_t Bytes = DL.getTypeAllocSize(Ty: CDS->getType());
4108 // Don't emit a 1-byte object as a .fill.
4109 if (Bytes > 1)
4110 return AP.OutStreamer->emitFill(NumBytes: Bytes, FillValue: Value);
4111 }
4112
4113 // If this can be emitted with .ascii/.asciz, emit it as such.
4114 if (CDS->isString())
4115 return AP.OutStreamer->emitBytes(Data: CDS->getAsString());
4116
4117 // Otherwise, emit the values in successive locations.
4118 uint64_t ElementByteSize = CDS->getElementByteSize();
4119 if (isa<IntegerType>(Val: CDS->getElementType()) ||
4120 isa<ByteType>(Val: CDS->getElementType())) {
4121 for (uint64_t I = 0, E = CDS->getNumElements(); I != E; ++I) {
4122 emitGlobalAliasInline(AP, Offset: ElementByteSize * I, AliasList);
4123 if (AP.isVerbose())
4124 AP.OutStreamer->getCommentOS()
4125 << format(Fmt: "0x%" PRIx64 "\n", Vals: CDS->getElementAsInteger(i: I));
4126 AP.OutStreamer->emitIntValue(Value: CDS->getElementAsInteger(i: I),
4127 Size: ElementByteSize);
4128 }
4129 } else {
4130 Type *ET = CDS->getElementType();
4131 for (uint64_t I = 0, E = CDS->getNumElements(); I != E; ++I) {
4132 emitGlobalAliasInline(AP, Offset: ElementByteSize * I, AliasList);
4133 emitGlobalConstantFP(APF: CDS->getElementAsAPFloat(i: I), ET, AP);
4134 }
4135 }
4136
4137 unsigned Size = DL.getTypeAllocSize(Ty: CDS->getType());
4138 unsigned EmittedSize =
4139 DL.getTypeAllocSize(Ty: CDS->getElementType()) * CDS->getNumElements();
4140 assert(EmittedSize <= Size && "Size cannot be less than EmittedSize!");
4141 if (unsigned Padding = Size - EmittedSize)
4142 AP.OutStreamer->emitZeros(NumBytes: Padding);
4143}
4144
4145static void emitGlobalConstantArray(const DataLayout &DL,
4146 const ConstantArray *CA, AsmPrinter &AP,
4147 const Constant *BaseCV, uint64_t Offset,
4148 AsmPrinter::AliasMapTy *AliasList) {
4149 // See if we can aggregate some values. Make sure it can be
4150 // represented as a series of bytes of the constant value.
4151 int Value = isRepeatedByteSequence(V: CA, DL);
4152
4153 if (Value != -1) {
4154 uint64_t Bytes = DL.getTypeAllocSize(Ty: CA->getType());
4155 AP.OutStreamer->emitFill(NumBytes: Bytes, FillValue: Value);
4156 } else {
4157 for (unsigned I = 0, E = CA->getNumOperands(); I != E; ++I) {
4158 emitGlobalConstantImpl(DL, C: CA->getOperand(i_nocapture: I), AP, BaseCV, Offset,
4159 AliasList);
4160 Offset += DL.getTypeAllocSize(Ty: CA->getOperand(i_nocapture: I)->getType());
4161 }
4162 }
4163}
4164
4165static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP);
4166
4167static void emitGlobalConstantVector(const DataLayout &DL, const Constant *CV,
4168 AsmPrinter &AP,
4169 AsmPrinter::AliasMapTy *AliasList) {
4170 uint64_t AllocSize = DL.getTypeAllocSize(Ty: CV->getType());
4171
4172 if (CV->isNullValue())
4173 return AP.OutStreamer->emitZeros(NumBytes: AllocSize);
4174
4175 auto *VTy = cast<FixedVectorType>(Val: CV->getType());
4176 Type *ElementType = VTy->getElementType();
4177 uint64_t ElementSizeInBits = DL.getTypeSizeInBits(Ty: ElementType);
4178 uint64_t ElementAllocSizeInBits = DL.getTypeAllocSizeInBits(Ty: ElementType);
4179 uint64_t EmittedSize;
4180 if (ElementSizeInBits != ElementAllocSizeInBits) {
4181 // If the allocation size of an element is different from the size in bits,
4182 // printing each element separately will insert incorrect padding.
4183 //
4184 // The general algorithm here is complicated; instead of writing it out
4185 // here, just use the existing code in ConstantFolding.
4186 Type *IntT =
4187 IntegerType::get(C&: CV->getContext(), NumBits: DL.getTypeSizeInBits(Ty: CV->getType()));
4188 ConstantInt *CI = dyn_cast_or_null<ConstantInt>(Val: ConstantFoldConstant(
4189 C: ConstantExpr::getBitCast(C: const_cast<Constant *>(CV), Ty: IntT), DL));
4190 if (!CI) {
4191 report_fatal_error(
4192 reason: "Cannot lower vector global with unusual element type");
4193 }
4194 emitGlobalAliasInline(AP, Offset: 0, AliasList);
4195 emitGlobalConstantLargeInt(CI, AP);
4196 EmittedSize = DL.getTypeStoreSize(Ty: CV->getType());
4197 } else {
4198 for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
4199 emitGlobalAliasInline(AP, Offset: AllocSize * I, AliasList);
4200 emitGlobalConstantImpl(DL, C: CV->getAggregateElement(Elt: I), AP);
4201 }
4202 EmittedSize = DL.getTypeAllocSize(Ty: ElementType) * VTy->getNumElements();
4203 }
4204
4205 if (unsigned Padding = AllocSize - EmittedSize)
4206 AP.OutStreamer->emitZeros(NumBytes: Padding);
4207}
4208
4209static void emitGlobalConstantStruct(const DataLayout &DL,
4210 const ConstantStruct *CS, AsmPrinter &AP,
4211 const Constant *BaseCV, uint64_t Offset,
4212 AsmPrinter::AliasMapTy *AliasList) {
4213 // Print the fields in successive locations. Pad to align if needed!
4214 uint64_t Size = DL.getTypeAllocSize(Ty: CS->getType());
4215 const StructLayout *Layout = DL.getStructLayout(Ty: CS->getType());
4216 uint64_t SizeSoFar = 0;
4217 for (unsigned I = 0, E = CS->getNumOperands(); I != E; ++I) {
4218 const Constant *Field = CS->getOperand(i_nocapture: I);
4219
4220 // Print the actual field value.
4221 emitGlobalConstantImpl(DL, C: Field, AP, BaseCV, Offset: Offset + SizeSoFar,
4222 AliasList);
4223
4224 // Check if padding is needed and insert one or more 0s.
4225 uint64_t FieldSize = DL.getTypeAllocSize(Ty: Field->getType());
4226 uint64_t PadSize = ((I == E - 1 ? Size : Layout->getElementOffset(Idx: I + 1)) -
4227 Layout->getElementOffset(Idx: I)) -
4228 FieldSize;
4229 SizeSoFar += FieldSize + PadSize;
4230
4231 // Insert padding - this may include padding to increase the size of the
4232 // current field up to the ABI size (if the struct is not packed) as well
4233 // as padding to ensure that the next field starts at the right offset.
4234 AP.OutStreamer->emitZeros(NumBytes: PadSize);
4235 }
4236 assert(SizeSoFar == Layout->getSizeInBytes() &&
4237 "Layout of constant struct may be incorrect!");
4238}
4239
4240static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP) {
4241 assert(ET && "Unknown float type");
4242 APInt API = APF.bitcastToAPInt();
4243
4244 // First print a comment with what we think the original floating-point value
4245 // should have been.
4246 if (AP.isVerbose()) {
4247 SmallString<8> StrVal;
4248 APF.toString(Str&: StrVal);
4249 ET->print(O&: AP.OutStreamer->getCommentOS());
4250 AP.OutStreamer->getCommentOS() << ' ' << StrVal << '\n';
4251 }
4252
4253 // Now iterate through the APInt chunks, emitting them in endian-correct
4254 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
4255 // floats).
4256 unsigned NumBytes = API.getBitWidth() / 8;
4257 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
4258 const uint64_t *p = API.getRawData();
4259
4260 // PPC's long double has odd notions of endianness compared to how LLVM
4261 // handles it: p[0] goes first for *big* endian on PPC.
4262 if (AP.getDataLayout().isBigEndian() && !ET->isPPC_FP128Ty()) {
4263 int Chunk = API.getNumWords() - 1;
4264
4265 if (TrailingBytes)
4266 AP.OutStreamer->emitIntValueInHexWithPadding(Value: p[Chunk--], Size: TrailingBytes);
4267
4268 for (; Chunk >= 0; --Chunk)
4269 AP.OutStreamer->emitIntValueInHexWithPadding(Value: p[Chunk], Size: sizeof(uint64_t));
4270 } else {
4271 unsigned Chunk;
4272 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
4273 AP.OutStreamer->emitIntValueInHexWithPadding(Value: p[Chunk], Size: sizeof(uint64_t));
4274
4275 if (TrailingBytes)
4276 AP.OutStreamer->emitIntValueInHexWithPadding(Value: p[Chunk], Size: TrailingBytes);
4277 }
4278
4279 // Emit the tail padding for the long double.
4280 const DataLayout &DL = AP.getDataLayout();
4281 AP.OutStreamer->emitZeros(NumBytes: DL.getTypeAllocSize(Ty: ET) - DL.getTypeStoreSize(Ty: ET));
4282}
4283
4284static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
4285 emitGlobalConstantFP(APF: CFP->getValueAPF(), ET: CFP->getType(), AP);
4286}
4287
4288static void emitGlobalConstantLargeAPInt(const APInt &Val,
4289 uint64_t TypeStoreSize,
4290 AsmPrinter &AP) {
4291 const DataLayout &DL = AP.getDataLayout();
4292 unsigned BitWidth = Val.getBitWidth();
4293
4294 // Copy the value as we may massage the layout for constants whose bit width
4295 // is not a multiple of 64-bits.
4296 APInt Realigned(Val);
4297 uint64_t ExtraBits = 0;
4298 unsigned ExtraBitsSize = BitWidth & 63;
4299
4300 if (ExtraBitsSize) {
4301 // The bit width of the data is not a multiple of 64-bits.
4302 // The extra bits are expected to be at the end of the chunk of the memory.
4303 // Little endian:
4304 // * Nothing to be done, just record the extra bits to emit.
4305 // Big endian:
4306 // * Record the extra bits to emit.
4307 // * Realign the raw data to emit the chunks of 64-bits.
4308 if (DL.isBigEndian()) {
4309 // Basically the structure of the raw data is a chunk of 64-bits cells:
4310 // 0 1 BitWidth / 64
4311 // [chunk1][chunk2] ... [chunkN].
4312 // The most significant chunk is chunkN and it should be emitted first.
4313 // However, due to the alignment issue chunkN contains useless bits.
4314 // Realign the chunks so that they contain only useful information:
4315 // ExtraBits 0 1 (BitWidth / 64) - 1
4316 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
4317 ExtraBitsSize = alignTo(Value: ExtraBitsSize, Align: 8);
4318 ExtraBits =
4319 Realigned.getRawData()[0] & (((uint64_t)-1) >> (64 - ExtraBitsSize));
4320 if (BitWidth >= 64)
4321 Realigned.lshrInPlace(ShiftAmt: ExtraBitsSize);
4322 } else
4323 ExtraBits = Realigned.getRawData()[BitWidth / 64];
4324 }
4325
4326 // We don't expect assemblers to support data directives
4327 // for more than 64 bits, so we emit the data in at most 64-bit
4328 // quantities at a time.
4329 const uint64_t *RawData = Realigned.getRawData();
4330 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
4331 uint64_t ChunkVal = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
4332 AP.OutStreamer->emitIntValue(Value: ChunkVal, Size: 8);
4333 }
4334
4335 if (ExtraBitsSize) {
4336 // Emit the extra bits after the 64-bits chunks.
4337
4338 // Emit a directive that fills the expected size.
4339 uint64_t Size = TypeStoreSize - (BitWidth / 64) * 8;
4340 assert(Size && Size * 8 >= ExtraBitsSize &&
4341 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) ==
4342 ExtraBits &&
4343 "Directive too small for extra bits.");
4344 AP.OutStreamer->emitIntValue(Value: ExtraBits, Size);
4345 }
4346}
4347
4348static void emitGlobalConstantLargeByte(const ConstantByte *CB,
4349 AsmPrinter &AP) {
4350 emitGlobalConstantLargeAPInt(
4351 Val: CB->getValue(), TypeStoreSize: AP.getDataLayout().getTypeStoreSize(Ty: CB->getType()), AP);
4352}
4353
4354static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
4355 emitGlobalConstantLargeAPInt(
4356 Val: CI->getValue(), TypeStoreSize: AP.getDataLayout().getTypeStoreSize(Ty: CI->getType()), AP);
4357}
4358
4359/// Transform a not absolute MCExpr containing a reference to a GOT
4360/// equivalent global, by a target specific GOT pc relative access to the
4361/// final symbol.
4362static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
4363 const Constant *BaseCst,
4364 uint64_t Offset) {
4365 // The global @foo below illustrates a global that uses a got equivalent.
4366 //
4367 // @bar = global i32 42
4368 // @gotequiv = private unnamed_addr constant i32* @bar
4369 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
4370 // i64 ptrtoint (i32* @foo to i64))
4371 // to i32)
4372 //
4373 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
4374 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
4375 // form:
4376 //
4377 // foo = cstexpr, where
4378 // cstexpr := <gotequiv> - "." + <cst>
4379 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
4380 //
4381 // After canonicalization by evaluateAsRelocatable `ME` turns into:
4382 //
4383 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
4384 // gotpcrelcst := <offset from @foo base> + <cst>
4385 MCValue MV;
4386 if (!(*ME)->evaluateAsRelocatable(Res&: MV, Asm: nullptr) || MV.isAbsolute())
4387 return;
4388 const MCSymbol *GOTEquivSym = MV.getAddSym();
4389 if (!GOTEquivSym)
4390 return;
4391
4392 // Check that GOT equivalent symbol is cached.
4393 if (!AP.GlobalGOTEquivs.count(Key: GOTEquivSym))
4394 return;
4395
4396 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(Val: BaseCst);
4397 if (!BaseGV)
4398 return;
4399
4400 // Check for a valid base symbol
4401 const MCSymbol *BaseSym = AP.getSymbol(GV: BaseGV);
4402 const MCSymbol *SymB = MV.getSubSym();
4403
4404 if (!SymB || BaseSym != SymB)
4405 return;
4406
4407 // Make sure to match:
4408 //
4409 // gotpcrelcst := <offset from @foo base> + <cst>
4410 //
4411 int64_t GOTPCRelCst = Offset + MV.getConstant();
4412 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
4413 return;
4414
4415 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
4416 //
4417 // bar:
4418 // .long 42
4419 // gotequiv:
4420 // .quad bar
4421 // foo:
4422 // .long gotequiv - "." + <cst>
4423 //
4424 // is replaced by the target specific equivalent to:
4425 //
4426 // bar:
4427 // .long 42
4428 // foo:
4429 // .long bar@GOTPCREL+<gotpcrelcst>
4430 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
4431 const GlobalVariable *GV = Result.first;
4432 int NumUses = (int)Result.second;
4433 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(Val: GV->getOperand(i_nocapture: 0));
4434 const MCSymbol *FinalSym = AP.getSymbol(GV: FinalGV);
4435 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
4436 GV: FinalGV, Sym: FinalSym, MV, Offset, MMI: AP.MMI, Streamer&: *AP.OutStreamer);
4437
4438 // Update GOT equivalent usage information
4439 --NumUses;
4440 if (NumUses >= 0)
4441 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(x&: GV, y&: NumUses);
4442}
4443
4444static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
4445 AsmPrinter &AP, const Constant *BaseCV,
4446 uint64_t Offset,
4447 AsmPrinter::AliasMapTy *AliasList) {
4448 assert((!AliasList || AP.TM.getTargetTriple().isOSBinFormatXCOFF()) &&
4449 "AliasList only expected for XCOFF");
4450 emitGlobalAliasInline(AP, Offset, AliasList);
4451 uint64_t Size = DL.getTypeAllocSize(Ty: CV->getType());
4452
4453 // Globals with sub-elements such as combinations of arrays and structs
4454 // are handled recursively by emitGlobalConstantImpl. Keep track of the
4455 // constant symbol base and the current position with BaseCV and Offset.
4456 if (!BaseCV && CV->hasOneUse())
4457 BaseCV = dyn_cast<Constant>(Val: CV->user_back());
4458
4459 if (isa<ConstantAggregateZero>(Val: CV)) {
4460 StructType *structType;
4461 if (AliasList && (structType = llvm::dyn_cast<StructType>(Val: CV->getType()))) {
4462 unsigned numElements = {structType->getNumElements()};
4463 if (numElements != 0) {
4464 // Handle cases of aliases to direct struct elements
4465 const StructLayout *Layout = DL.getStructLayout(Ty: structType);
4466 uint64_t SizeSoFar = 0;
4467 for (unsigned int i = 0; i < numElements - 1; ++i) {
4468 uint64_t GapToNext = Layout->getElementOffset(Idx: i + 1) - SizeSoFar;
4469 AP.OutStreamer->emitZeros(NumBytes: GapToNext);
4470 SizeSoFar += GapToNext;
4471 emitGlobalAliasInline(AP, Offset: Offset + SizeSoFar, AliasList);
4472 }
4473 AP.OutStreamer->emitZeros(NumBytes: Size - SizeSoFar);
4474 return;
4475 }
4476 }
4477 return AP.OutStreamer->emitZeros(NumBytes: Size);
4478 }
4479
4480 if (isa<UndefValue>(Val: CV))
4481 return AP.OutStreamer->emitZeros(NumBytes: Size);
4482
4483 if (const ConstantInt *CI = dyn_cast<ConstantInt>(Val: CV)) {
4484 if (isa<VectorType>(Val: CV->getType()))
4485 return emitGlobalConstantVector(DL, CV, AP, AliasList);
4486
4487 const uint64_t StoreSize = DL.getTypeStoreSize(Ty: CV->getType());
4488 if (StoreSize <= 8) {
4489 if (AP.isVerbose())
4490 AP.OutStreamer->getCommentOS()
4491 << format(Fmt: "0x%" PRIx64 "\n", Vals: CI->getZExtValue());
4492 AP.OutStreamer->emitIntValue(Value: CI->getZExtValue(), Size: StoreSize);
4493 } else {
4494 emitGlobalConstantLargeInt(CI, AP);
4495 }
4496
4497 // Emit tail padding if needed
4498 if (Size != StoreSize)
4499 AP.OutStreamer->emitZeros(NumBytes: Size - StoreSize);
4500
4501 return;
4502 }
4503
4504 if (const ConstantByte *CB = dyn_cast<ConstantByte>(Val: CV)) {
4505 if (isa<VectorType>(Val: CV->getType()))
4506 return emitGlobalConstantVector(DL, CV, AP, AliasList);
4507
4508 const uint64_t StoreSize = DL.getTypeStoreSize(Ty: CV->getType());
4509 if (StoreSize <= 8) {
4510 if (AP.isVerbose())
4511 AP.OutStreamer->getCommentOS()
4512 << format(Fmt: "0x%" PRIx64 "\n", Vals: CB->getZExtValue());
4513 AP.OutStreamer->emitIntValue(Value: CB->getZExtValue(), Size: StoreSize);
4514 } else {
4515 emitGlobalConstantLargeByte(CB, AP);
4516 }
4517
4518 // Emit tail padding if needed
4519 if (Size != StoreSize)
4520 AP.OutStreamer->emitZeros(NumBytes: Size - StoreSize);
4521
4522 return;
4523 }
4524
4525 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(Val: CV)) {
4526 if (isa<VectorType>(Val: CV->getType()))
4527 return emitGlobalConstantVector(DL, CV, AP, AliasList);
4528 else
4529 return emitGlobalConstantFP(CFP, AP);
4530 }
4531
4532 if (isa<ConstantPointerNull>(Val: CV)) {
4533 AP.OutStreamer->emitIntValue(Value: 0, Size);
4534 return;
4535 }
4536
4537 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(Val: CV))
4538 return emitGlobalConstantDataSequential(DL, CDS, AP, AliasList);
4539
4540 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(Val: CV))
4541 return emitGlobalConstantArray(DL, CA: CVA, AP, BaseCV, Offset, AliasList);
4542
4543 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(Val: CV))
4544 return emitGlobalConstantStruct(DL, CS: CVS, AP, BaseCV, Offset, AliasList);
4545
4546 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Val: CV)) {
4547 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
4548 // vectors).
4549 if (CE->getOpcode() == Instruction::BitCast)
4550 return emitGlobalConstantImpl(DL, CV: CE->getOperand(i_nocapture: 0), AP);
4551
4552 if (Size > 8) {
4553 // If the constant expression's size is greater than 64-bits, then we have
4554 // to emit the value in chunks. Try to constant fold the value and emit it
4555 // that way.
4556 Constant *New = ConstantFoldConstant(C: CE, DL);
4557 if (New != CE)
4558 return emitGlobalConstantImpl(DL, CV: New, AP);
4559 }
4560 }
4561
4562 if (isa<ConstantVector>(Val: CV))
4563 return emitGlobalConstantVector(DL, CV, AP, AliasList);
4564
4565 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
4566 // thread the streamer with EmitValue.
4567 const MCExpr *ME = AP.lowerConstant(CV, BaseCV, Offset);
4568
4569 // Since lowerConstant already folded and got rid of all IR pointer and
4570 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
4571 // directly.
4572 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
4573 handleIndirectSymViaGOTPCRel(AP, ME: &ME, BaseCst: BaseCV, Offset);
4574
4575 AP.OutStreamer->emitValue(Value: ME, Size);
4576}
4577
4578/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
4579void AsmPrinter::emitGlobalConstant(const DataLayout &DL, const Constant *CV,
4580 AliasMapTy *AliasList) {
4581 uint64_t Size = DL.getTypeAllocSize(Ty: CV->getType());
4582 if (Size)
4583 emitGlobalConstantImpl(DL, CV, AP&: *this, BaseCV: nullptr, Offset: 0, AliasList);
4584 else if (MAI.hasSubsectionsViaSymbols()) {
4585 // If the global has zero size, emit a single byte so that two labels don't
4586 // look like they are at the same location.
4587 OutStreamer->emitIntValue(Value: 0, Size: 1);
4588 }
4589 if (!AliasList)
4590 return;
4591 // TODO: These remaining aliases are not emitted in the correct location. Need
4592 // to handle the case where the alias offset doesn't refer to any sub-element.
4593 for (auto &AliasPair : *AliasList) {
4594 for (const GlobalAlias *GA : AliasPair.second)
4595 OutStreamer->emitLabel(Symbol: getSymbol(GV: GA));
4596 }
4597}
4598
4599void AsmPrinter::emitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
4600 // Target doesn't support this yet!
4601 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
4602}
4603
4604void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
4605 if (Offset > 0)
4606 OS << '+' << Offset;
4607 else if (Offset < 0)
4608 OS << Offset;
4609}
4610
4611void AsmPrinter::emitNops(unsigned N) {
4612 MCInst Nop = MF->getSubtarget().getInstrInfo()->getNop();
4613 for (; N; --N)
4614 EmitToStreamer(S&: *OutStreamer, Inst: Nop);
4615}
4616
4617//===----------------------------------------------------------------------===//
4618// Symbol Lowering Routines.
4619//===----------------------------------------------------------------------===//
4620
4621MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
4622 return OutContext.createTempSymbol(Name, AlwaysAddSuffix: true);
4623}
4624
4625MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
4626 return const_cast<AsmPrinter *>(this)->getAddrLabelSymbol(
4627 BB: BA->getBasicBlock());
4628}
4629
4630MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
4631 return const_cast<AsmPrinter *>(this)->getAddrLabelSymbol(BB);
4632}
4633
4634const MCExpr *AsmPrinter::lowerBlockAddressConstant(const BlockAddress &BA) {
4635 return MCSymbolRefExpr::create(Symbol: GetBlockAddressSymbol(BA: &BA), Ctx&: OutContext);
4636}
4637
4638/// GetCPISymbol - Return the symbol for the specified constant pool entry.
4639MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
4640 if (getSubtargetInfo().getTargetTriple().isWindowsMSVCEnvironment() ||
4641 getSubtargetInfo().getTargetTriple().isUEFI()) {
4642 const MachineConstantPoolEntry &CPE =
4643 MF->getConstantPool()->getConstants()[CPID];
4644 if (!CPE.isMachineConstantPoolEntry()) {
4645 const DataLayout &DL = MF->getDataLayout();
4646 SectionKind Kind = CPE.getSectionKind(DL: &DL);
4647 const Constant *C = CPE.Val.ConstVal;
4648 Align Alignment = CPE.Alignment;
4649 auto *S = getObjFileLowering().getSectionForConstant(
4650 DL, Kind, C, Alignment, F: &MF->getFunction());
4651 if (S && TM.getTargetTriple().isOSBinFormatCOFF()) {
4652 if (MCSymbol *Sym =
4653 static_cast<const MCSectionCOFF *>(S)->getCOMDATSymbol()) {
4654 if (Sym->isUndefined())
4655 OutStreamer->emitSymbolAttribute(Symbol: Sym, Attribute: MCSA_Global);
4656 return Sym;
4657 }
4658 }
4659 }
4660 }
4661
4662 const DataLayout &DL = getDataLayout();
4663 return OutContext.getOrCreateSymbol(Name: Twine(DL.getInternalSymbolPrefix()) +
4664 "CPI" + Twine(getFunctionNumber()) + "_" +
4665 Twine(CPID));
4666}
4667
4668/// GetJTISymbol - Return the symbol for the specified jump table entry.
4669MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
4670 return MF->getJTISymbol(JTI: JTID, Ctx&: OutContext, isLinkerPrivate);
4671}
4672
4673/// GetJTSetSymbol - Return the symbol for the specified jump table .set
4674/// FIXME: privatize to AsmPrinter.
4675MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
4676 const DataLayout &DL = getDataLayout();
4677 return OutContext.getOrCreateSymbol(Name: Twine(DL.getInternalSymbolPrefix()) +
4678 Twine(getFunctionNumber()) + "_" +
4679 Twine(UID) + "_set_" + Twine(MBBID));
4680}
4681
4682MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
4683 StringRef Suffix) const {
4684 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, TM);
4685}
4686
4687/// Return the MCSymbol for the specified ExternalSymbol.
4688MCSymbol *AsmPrinter::GetExternalSymbolSymbol(const Twine &Sym) const {
4689 SmallString<60> NameStr;
4690 Mangler::getNameWithPrefix(OutName&: NameStr, GVName: Sym, DL: getDataLayout());
4691 return OutContext.getOrCreateSymbol(Name: NameStr);
4692}
4693
4694/// PrintParentLoopComment - Print comments about parent loops of this one.
4695static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
4696 unsigned FunctionNumber) {
4697 if (!Loop) return;
4698 PrintParentLoopComment(OS, Loop: Loop->getParentLoop(), FunctionNumber);
4699 OS.indent(NumSpaces: Loop->getLoopDepth()*2)
4700 << "Parent Loop BB" << FunctionNumber << "_"
4701 << Loop->getHeader()->getNumber()
4702 << " Depth=" << Loop->getLoopDepth() << '\n';
4703}
4704
4705/// PrintChildLoopComment - Print comments about child loops within
4706/// the loop for this basic block, with nesting.
4707static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
4708 unsigned FunctionNumber) {
4709 // Add child loop information
4710 for (const MachineLoop *CL : *Loop) {
4711 OS.indent(NumSpaces: CL->getLoopDepth()*2)
4712 << "Child Loop BB" << FunctionNumber << "_"
4713 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
4714 << '\n';
4715 PrintChildLoopComment(OS, Loop: CL, FunctionNumber);
4716 }
4717}
4718
4719/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
4720static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
4721 const MachineLoopInfo *LI,
4722 const AsmPrinter &AP) {
4723 // Add loop depth information
4724 const MachineLoop *Loop = LI->getLoopFor(BB: &MBB);
4725 if (!Loop) return;
4726
4727 MachineBasicBlock *Header = Loop->getHeader();
4728 assert(Header && "No header for loop");
4729
4730 // If this block is not a loop header, just print out what is the loop header
4731 // and return.
4732 if (Header != &MBB) {
4733 AP.OutStreamer->AddComment(T: " in Loop: Header=BB" +
4734 Twine(AP.getFunctionNumber())+"_" +
4735 Twine(Loop->getHeader()->getNumber())+
4736 " Depth="+Twine(Loop->getLoopDepth()));
4737 return;
4738 }
4739
4740 // Otherwise, it is a loop header. Print out information about child and
4741 // parent loops.
4742 raw_ostream &OS = AP.OutStreamer->getCommentOS();
4743
4744 PrintParentLoopComment(OS, Loop: Loop->getParentLoop(), FunctionNumber: AP.getFunctionNumber());
4745
4746 OS << "=>";
4747 OS.indent(NumSpaces: Loop->getLoopDepth()*2-2);
4748
4749 OS << "This ";
4750 if (Loop->isInnermost())
4751 OS << "Inner ";
4752 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
4753
4754 PrintChildLoopComment(OS, Loop, FunctionNumber: AP.getFunctionNumber());
4755}
4756
4757/// emitBasicBlockStart - This method prints the label for the specified
4758/// MachineBasicBlock, an alignment (if present) and a comment describing
4759/// it if appropriate.
4760void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
4761 // End the previous funclet and start a new one.
4762 if (MBB.isEHFuncletEntry()) {
4763 for (auto &Handler : Handlers) {
4764 Handler->endFunclet();
4765 Handler->beginFunclet(MBB);
4766 }
4767 for (auto &Handler : EHHandlers) {
4768 Handler->endFunclet();
4769 Handler->beginFunclet(MBB);
4770 }
4771 }
4772
4773 // Switch to a new section if this basic block must begin a section. The
4774 // entry block is always placed in the function section and is handled
4775 // separately.
4776 if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
4777 OutStreamer->switchSection(
4778 Section: getObjFileLowering().getSectionForMachineBasicBlock(F: MF->getFunction(),
4779 MBB, TM));
4780 CurrentSectionBeginSym = MBB.getSymbol();
4781 }
4782
4783 for (auto &Handler : Handlers)
4784 Handler->beginCodeAlignment(MBB);
4785
4786 // Emit an alignment directive for this block, if needed.
4787 const Align Alignment = MBB.getAlignment();
4788 if (Alignment != Align(1))
4789 emitAlignment(Alignment, GV: nullptr, MaxBytesToEmit: MBB.getMaxBytesForAlignment());
4790
4791 // If the block has its address taken, emit any labels that were used to
4792 // reference the block. It is possible that there is more than one label
4793 // here, because multiple LLVM BB's may have been RAUW'd to this block after
4794 // the references were generated.
4795 if (MBB.isIRBlockAddressTaken()) {
4796 if (isVerbose())
4797 OutStreamer->AddComment(T: "Block address taken");
4798
4799 BasicBlock *BB = MBB.getAddressTakenIRBlock();
4800 assert(BB && BB->hasAddressTaken() && "Missing BB");
4801 for (MCSymbol *Sym : getAddrLabelSymbolToEmit(BB))
4802 OutStreamer->emitLabel(Symbol: Sym);
4803 } else if (isVerbose() && MBB.isMachineBlockAddressTaken()) {
4804 OutStreamer->AddComment(T: "Block address taken");
4805 } else if (isVerbose() && MBB.isInlineAsmBrIndirectTarget()) {
4806 OutStreamer->AddComment(T: "Inline asm indirect target");
4807 }
4808
4809 // Print some verbose block comments.
4810 if (isVerbose()) {
4811 if (const BasicBlock *BB = MBB.getBasicBlock()) {
4812 if (BB->hasName()) {
4813 BB->printAsOperand(O&: OutStreamer->getCommentOS(),
4814 /*PrintType=*/false, M: BB->getModule());
4815 OutStreamer->getCommentOS() << '\n';
4816 }
4817 }
4818
4819 assert(MLI != nullptr && "MachineLoopInfo should has been computed");
4820 emitBasicBlockLoopComments(MBB, LI: MLI, AP: *this);
4821 }
4822
4823 // Print the main label for the block.
4824 if (shouldEmitLabelForBasicBlock(MBB)) {
4825 if (isVerbose() && MBB.hasLabelMustBeEmitted())
4826 OutStreamer->AddComment(T: "Label of block must be emitted");
4827 OutStreamer->emitLabel(Symbol: MBB.getSymbol());
4828 } else {
4829 if (isVerbose()) {
4830 // NOTE: Want this comment at start of line, don't emit with AddComment.
4831 OutStreamer->emitRawComment(T: " %bb." + Twine(MBB.getNumber()) + ":",
4832 TabPrefix: false);
4833 }
4834 }
4835
4836 if (MBB.isEHContTarget() &&
4837 MAI.getExceptionHandlingType() == ExceptionHandling::WinEH) {
4838 OutStreamer->emitLabel(Symbol: MBB.getEHContSymbol());
4839 }
4840
4841 // With BB sections, each basic block must handle CFI information on its own
4842 // if it begins a section (Entry block call is handled separately, next to
4843 // beginFunction).
4844 if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
4845 for (auto &Handler : Handlers)
4846 Handler->beginBasicBlockSection(MBB);
4847 for (auto &Handler : EHHandlers)
4848 Handler->beginBasicBlockSection(MBB);
4849 }
4850}
4851
4852void AsmPrinter::emitBasicBlockEnd(const MachineBasicBlock &MBB) {
4853 // Check if CFI information needs to be updated for this MBB with basic block
4854 // sections.
4855 if (MBB.isEndSection()) {
4856 for (auto &Handler : Handlers)
4857 Handler->endBasicBlockSection(MBB);
4858 for (auto &Handler : EHHandlers)
4859 Handler->endBasicBlockSection(MBB);
4860 }
4861}
4862
4863void AsmPrinter::emitVisibility(MCSymbol *Sym, unsigned Visibility,
4864 bool IsDefinition) const {
4865 MCSymbolAttr Attr = MCSA_Invalid;
4866
4867 switch (Visibility) {
4868 default: break;
4869 case GlobalValue::HiddenVisibility:
4870 if (IsDefinition)
4871 Attr = MAI.getHiddenVisibilityAttr();
4872 else
4873 Attr = MAI.getHiddenDeclarationVisibilityAttr();
4874 break;
4875 case GlobalValue::ProtectedVisibility:
4876 Attr = MAI.getProtectedVisibilityAttr();
4877 break;
4878 }
4879
4880 if (Attr != MCSA_Invalid)
4881 OutStreamer->emitSymbolAttribute(Symbol: Sym, Attribute: Attr);
4882}
4883
4884bool AsmPrinter::shouldEmitLabelForBasicBlock(
4885 const MachineBasicBlock &MBB) const {
4886 // With `-fbasic-block-sections=`, a label is needed for every non-entry block
4887 // in the labels mode (option `=labels`) and every section beginning in the
4888 // sections mode (`=all` and `=list=`).
4889 if ((MF->getTarget().Options.BBAddrMap || MBB.isBeginSection()) &&
4890 !MBB.isEntryBlock())
4891 return true;
4892 // A label is needed for any block with at least one predecessor (when that
4893 // predecessor is not the fallthrough predecessor, or if it is an EH funclet
4894 // entry, or if a label is forced).
4895 return !MBB.pred_empty() &&
4896 (!isBlockOnlyReachableByFallthrough(MBB: &MBB) || MBB.isEHFuncletEntry() ||
4897 MBB.hasLabelMustBeEmitted());
4898}
4899
4900/// isBlockOnlyReachableByFallthough - Return true if the basic block has
4901/// exactly one predecessor and the control transfer mechanism between
4902/// the predecessor and this block is a fall-through.
4903bool AsmPrinter::
4904isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
4905 // If this is a landing pad, it isn't a fall through. If it has no preds,
4906 // then nothing falls through to it.
4907 if (MBB->isEHPad() || MBB->pred_empty())
4908 return false;
4909
4910 // If there isn't exactly one predecessor, it can't be a fall through.
4911 if (MBB->pred_size() > 1)
4912 return false;
4913
4914 // The predecessor has to be immediately before this block.
4915 MachineBasicBlock *Pred = *MBB->pred_begin();
4916 if (!Pred->isLayoutSuccessor(MBB))
4917 return false;
4918
4919 // If the block is completely empty, then it definitely does fall through.
4920 if (Pred->empty())
4921 return true;
4922
4923 // Check the terminators in the previous blocks
4924 for (const auto &MI : Pred->terminators()) {
4925 // If it is not a simple branch, we are in a table somewhere.
4926 if (!MI.isBranch() || MI.isIndirectBranch())
4927 return false;
4928
4929 // If we are the operands of one of the branches, this is not a fall
4930 // through. Note that targets with delay slots will usually bundle
4931 // terminators with the delay slot instruction.
4932 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
4933 if (OP->isJTI())
4934 return false;
4935 if (OP->isMBB() && OP->getMBB() == MBB)
4936 return false;
4937 }
4938 }
4939
4940 return true;
4941}
4942
4943GCMetadataPrinter *AsmPrinter::getOrCreateGCPrinter(GCStrategy &S) {
4944 if (!S.usesMetadata())
4945 return nullptr;
4946
4947 auto [GCPI, Inserted] = GCMetadataPrinters.try_emplace(Key: &S);
4948 if (!Inserted)
4949 return GCPI->second.get();
4950
4951 auto Name = S.getName();
4952
4953 for (const GCMetadataPrinterRegistry::entry &GCMetaPrinter :
4954 GCMetadataPrinterRegistry::entries())
4955 if (Name == GCMetaPrinter.getName()) {
4956 std::unique_ptr<GCMetadataPrinter> GMP = GCMetaPrinter.instantiate();
4957 GMP->S = &S;
4958 GCPI->second = std::move(GMP);
4959 return GCPI->second.get();
4960 }
4961
4962 report_fatal_error(reason: "no GCMetadataPrinter registered for GC: " + Twine(Name));
4963}
4964
4965void AsmPrinter::addAsmPrinterHandler(
4966 std::unique_ptr<AsmPrinterHandler> Handler) {
4967 Handlers.insert(I: Handlers.begin(), Elt: std::move(Handler));
4968 NumUserHandlers++;
4969}
4970
4971/// Pin vtables to this file.
4972AsmPrinterHandler::~AsmPrinterHandler() = default;
4973
4974void AsmPrinterHandler::markFunctionEnd() {}
4975
4976// In the binary's "xray_instr_map" section, an array of these function entries
4977// describes each instrumentation point. When XRay patches your code, the index
4978// into this table will be given to your handler as a patch point identifier.
4979void AsmPrinter::XRayFunctionEntry::emit(int Bytes, MCStreamer *Out) const {
4980 auto Kind8 = static_cast<uint8_t>(Kind);
4981 Out->emitBinaryData(Data: StringRef(reinterpret_cast<const char *>(&Kind8), 1));
4982 Out->emitBinaryData(
4983 Data: StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
4984 Out->emitBinaryData(Data: StringRef(reinterpret_cast<const char *>(&Version), 1));
4985 auto Padding = (4 * Bytes) - ((2 * Bytes) + 3);
4986 assert(Padding >= 0 && "Instrumentation map entry > 4 * Word Size");
4987 Out->emitZeros(NumBytes: Padding);
4988}
4989
4990void AsmPrinter::emitXRayTable() {
4991 if (Sleds.empty())
4992 return;
4993
4994 auto PrevSection = OutStreamer->getCurrentSectionOnly();
4995 const Function &F = MF->getFunction();
4996 MCSection *InstMap = nullptr;
4997 MCSection *FnSledIndex = nullptr;
4998 const Triple &TT = TM.getTargetTriple();
4999 // Use PC-relative addresses on all targets.
5000 if (TT.isOSBinFormatELF()) {
5001 auto LinkedToSym = static_cast<const MCSymbolELF *>(CurrentFnSym);
5002 auto Flags = ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
5003 StringRef GroupName;
5004 if (F.hasComdat()) {
5005 Flags |= ELF::SHF_GROUP;
5006 GroupName = F.getComdat()->getName();
5007 }
5008 InstMap = OutContext.getELFSection(Section: "xray_instr_map", Type: ELF::SHT_PROGBITS,
5009 Flags, EntrySize: 0, Group: GroupName, IsComdat: F.hasComdat(),
5010 UniqueID: MCSection::NonUniqueID, LinkedToSym);
5011
5012 if (TM.Options.XRayFunctionIndex)
5013 FnSledIndex = OutContext.getELFSection(
5014 Section: "xray_fn_idx", Type: ELF::SHT_PROGBITS, Flags, EntrySize: 0, Group: GroupName, IsComdat: F.hasComdat(),
5015 UniqueID: MCSection::NonUniqueID, LinkedToSym);
5016 } else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
5017 InstMap = OutContext.getMachOSection(Segment: "__DATA", Section: "xray_instr_map",
5018 TypeAndAttributes: MachO::S_ATTR_LIVE_SUPPORT,
5019 K: SectionKind::getReadOnlyWithRel());
5020 if (TM.Options.XRayFunctionIndex)
5021 FnSledIndex = OutContext.getMachOSection(Segment: "__DATA", Section: "xray_fn_idx",
5022 TypeAndAttributes: MachO::S_ATTR_LIVE_SUPPORT,
5023 K: SectionKind::getReadOnly());
5024 } else {
5025 llvm_unreachable("Unsupported target");
5026 }
5027
5028 auto WordSizeBytes = MAI.getCodePointerSize();
5029
5030 // Now we switch to the instrumentation map section. Because this is done
5031 // per-function, we are able to create an index entry that will represent the
5032 // range of sleds associated with a function.
5033 auto &Ctx = OutContext;
5034 MCSymbol *SledsStart =
5035 OutContext.createLinkerPrivateSymbol(Name: "xray_sleds_start");
5036 OutStreamer->switchSection(Section: InstMap);
5037 OutStreamer->emitLabel(Symbol: SledsStart);
5038 for (const auto &Sled : Sleds) {
5039 MCSymbol *Dot = Ctx.createTempSymbol();
5040 OutStreamer->emitLabel(Symbol: Dot);
5041 OutStreamer->emitValueImpl(
5042 Value: MCBinaryExpr::createSub(LHS: MCSymbolRefExpr::create(Symbol: Sled.Sled, Ctx),
5043 RHS: MCSymbolRefExpr::create(Symbol: Dot, Ctx), Ctx),
5044 Size: WordSizeBytes);
5045 OutStreamer->emitValueImpl(
5046 Value: MCBinaryExpr::createSub(
5047 LHS: MCSymbolRefExpr::create(Symbol: CurrentFnBegin, Ctx),
5048 RHS: MCBinaryExpr::createAdd(LHS: MCSymbolRefExpr::create(Symbol: Dot, Ctx),
5049 RHS: MCConstantExpr::create(Value: WordSizeBytes, Ctx),
5050 Ctx),
5051 Ctx),
5052 Size: WordSizeBytes);
5053 Sled.emit(Bytes: WordSizeBytes, Out: OutStreamer.get());
5054 }
5055 MCSymbol *SledsEnd = OutContext.createTempSymbol(Name: "xray_sleds_end", AlwaysAddSuffix: true);
5056 OutStreamer->emitLabel(Symbol: SledsEnd);
5057
5058 // We then emit a single entry in the index per function. We use the symbols
5059 // that bound the instrumentation map as the range for a specific function.
5060 // Each entry contains 2 words and needs to be word-aligned.
5061 if (FnSledIndex) {
5062 OutStreamer->switchSection(Section: FnSledIndex);
5063 OutStreamer->emitValueToAlignment(Alignment: Align(WordSizeBytes));
5064 // For Mach-O, use an "l" symbol as the atom of this subsection. The label
5065 // difference uses a SUBTRACTOR external relocation which references the
5066 // symbol.
5067 MCSymbol *Dot = Ctx.createLinkerPrivateSymbol(Name: "xray_fn_idx");
5068 OutStreamer->emitLabel(Symbol: Dot);
5069 OutStreamer->emitValueImpl(
5070 Value: MCBinaryExpr::createSub(LHS: MCSymbolRefExpr::create(Symbol: SledsStart, Ctx),
5071 RHS: MCSymbolRefExpr::create(Symbol: Dot, Ctx), Ctx),
5072 Size: WordSizeBytes);
5073 OutStreamer->emitValueImpl(Value: MCConstantExpr::create(Value: Sleds.size(), Ctx),
5074 Size: WordSizeBytes);
5075 OutStreamer->switchSection(Section: PrevSection);
5076 }
5077 Sleds.clear();
5078}
5079
5080void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
5081 SledKind Kind, uint8_t Version) {
5082 const Function &F = MI.getMF()->getFunction();
5083 auto Attr = F.getFnAttribute(Kind: "function-instrument");
5084 bool LogArgs = F.hasFnAttribute(Kind: "xray-log-args");
5085 bool AlwaysInstrument =
5086 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
5087 if (Kind == SledKind::FUNCTION_ENTER && LogArgs)
5088 Kind = SledKind::LOG_ARGS_ENTER;
5089 Sleds.emplace_back(Args: XRayFunctionEntry{.Sled: Sled, .Function: CurrentFnSym, .Kind: Kind,
5090 .AlwaysInstrument: AlwaysInstrument, .Fn: &F, .Version: Version});
5091}
5092
5093void AsmPrinter::emitPatchableFunctionEntries() {
5094 const Function &F = MF->getFunction();
5095 unsigned PatchableFunctionPrefix =
5096 F.getFnAttributeAsParsedInteger(Kind: "patchable-function-prefix");
5097 unsigned PatchableFunctionEntry =
5098 F.getFnAttributeAsParsedInteger(Kind: "patchable-function-entry");
5099 if (!PatchableFunctionPrefix && !PatchableFunctionEntry)
5100 return;
5101 const unsigned PointerSize = getPointerSize();
5102 if (TM.getTargetTriple().isOSBinFormatELF()) {
5103 auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC;
5104 const MCSymbolELF *LinkedToSym = nullptr;
5105 StringRef GroupName, SectionName;
5106
5107 if (F.hasFnAttribute(Kind: "patchable-function-entry-section"))
5108 SectionName = F.getFnAttribute(Kind: "patchable-function-entry-section")
5109 .getValueAsString();
5110 if (SectionName.empty())
5111 SectionName = "__patchable_function_entries";
5112
5113 // GNU as < 2.35 did not support section flag 'o'. GNU ld < 2.36 did not
5114 // support mixed SHF_LINK_ORDER and non-SHF_LINK_ORDER sections.
5115 if (MAI.useIntegratedAssembler() || MAI.binutilsIsAtLeast(Major: 2, Minor: 36)) {
5116 Flags |= ELF::SHF_LINK_ORDER;
5117 if (F.hasComdat()) {
5118 Flags |= ELF::SHF_GROUP;
5119 GroupName = F.getComdat()->getName();
5120 }
5121 LinkedToSym = static_cast<const MCSymbolELF *>(CurrentFnSym);
5122 }
5123 OutStreamer->switchSection(Section: OutContext.getELFSection(
5124 Section: SectionName, Type: ELF::SHT_PROGBITS, Flags, EntrySize: 0, Group: GroupName, IsComdat: F.hasComdat(),
5125 UniqueID: MCSection::NonUniqueID, LinkedToSym));
5126 emitAlignment(Alignment: Align(PointerSize));
5127 OutStreamer->emitSymbolValue(Sym: CurrentPatchableFunctionEntrySym, Size: PointerSize);
5128 }
5129}
5130
5131uint16_t AsmPrinter::getDwarfVersion() const {
5132 return OutStreamer->getContext().getDwarfVersion();
5133}
5134
5135void AsmPrinter::setDwarfVersion(uint16_t Version) {
5136 OutStreamer->getContext().setDwarfVersion(Version);
5137}
5138
5139bool AsmPrinter::isDwarf64() const {
5140 return OutStreamer->getContext().getDwarfFormat() == dwarf::DWARF64;
5141}
5142
5143unsigned int AsmPrinter::getDwarfOffsetByteSize() const {
5144 return dwarf::getDwarfOffsetByteSize(
5145 Format: OutStreamer->getContext().getDwarfFormat());
5146}
5147
5148dwarf::FormParams AsmPrinter::getDwarfFormParams() const {
5149 return {.Version: getDwarfVersion(), .AddrSize: uint8_t(MAI.getCodePointerSize()),
5150 .Format: OutStreamer->getContext().getDwarfFormat(),
5151 .DwarfUsesRelocationsAcrossSections: doesDwarfUseRelocationsAcrossSections()};
5152}
5153
5154unsigned int AsmPrinter::getUnitLengthFieldByteSize() const {
5155 return dwarf::getUnitLengthFieldByteSize(
5156 Format: OutStreamer->getContext().getDwarfFormat());
5157}
5158
5159std::tuple<const MCSymbol *, uint64_t, const MCSymbol *,
5160 codeview::JumpTableEntrySize>
5161AsmPrinter::getCodeViewJumpTableInfo(int JTI, const MachineInstr *BranchInstr,
5162 const MCSymbol *BranchLabel) const {
5163 const auto TLI = MF->getSubtarget().getTargetLowering();
5164 const auto BaseExpr =
5165 TLI->getPICJumpTableRelocBaseExpr(MF, JTI, Ctx&: MMI->getContext());
5166 const auto Base = &cast<MCSymbolRefExpr>(Val: BaseExpr)->getSymbol();
5167
5168 // By default, for the architectures that support CodeView,
5169 // EK_LabelDifference32 is implemented as an Int32 from the base address.
5170 return std::make_tuple(args: Base, args: 0, args&: BranchLabel,
5171 args: codeview::JumpTableEntrySize::Int32);
5172}
5173
5174void AsmPrinter::emitCOFFReplaceableFunctionData(Module &M) {
5175 const Triple &TT = TM.getTargetTriple();
5176 assert(TT.isOSBinFormatCOFF());
5177
5178 bool IsTargetArm64EC = TT.isWindowsArm64EC();
5179 SmallVector<char> Buf;
5180 SmallVector<MCSymbol *> FuncOverrideDefaultSymbols;
5181 bool SwitchedToDirectiveSection = false;
5182 for (const Function &F : M.functions()) {
5183 if (F.hasFnAttribute(Kind: "loader-replaceable")) {
5184 if (!SwitchedToDirectiveSection) {
5185 OutStreamer->switchSection(
5186 Section: OutContext.getObjectFileInfo()->getDrectveSection());
5187 SwitchedToDirectiveSection = true;
5188 }
5189
5190 StringRef Name = F.getName();
5191
5192 // For hybrid-patchable targets, strip the prefix so that we can mark
5193 // the real function as replaceable.
5194 if (IsTargetArm64EC && Name.ends_with(Suffix: HybridPatchableTargetSuffix)) {
5195 Name = Name.drop_back(N: HybridPatchableTargetSuffix.size());
5196 }
5197
5198 MCSymbol *FuncOverrideSymbol =
5199 MMI->getContext().getOrCreateSymbol(Name: Name + "_$fo$");
5200 OutStreamer->beginCOFFSymbolDef(Symbol: FuncOverrideSymbol);
5201 OutStreamer->emitCOFFSymbolStorageClass(StorageClass: COFF::IMAGE_SYM_CLASS_EXTERNAL);
5202 OutStreamer->emitCOFFSymbolType(Type: COFF::IMAGE_SYM_DTYPE_NULL);
5203 OutStreamer->endCOFFSymbolDef();
5204
5205 MCSymbol *FuncOverrideDefaultSymbol =
5206 MMI->getContext().getOrCreateSymbol(Name: Name + "_$fo_default$");
5207 OutStreamer->beginCOFFSymbolDef(Symbol: FuncOverrideDefaultSymbol);
5208 OutStreamer->emitCOFFSymbolStorageClass(StorageClass: COFF::IMAGE_SYM_CLASS_EXTERNAL);
5209 OutStreamer->emitCOFFSymbolType(Type: COFF::IMAGE_SYM_DTYPE_NULL);
5210 OutStreamer->endCOFFSymbolDef();
5211 FuncOverrideDefaultSymbols.push_back(Elt: FuncOverrideDefaultSymbol);
5212
5213 OutStreamer->emitBytes(Data: (Twine(" /ALTERNATENAME:") +
5214 FuncOverrideSymbol->getName() + "=" +
5215 FuncOverrideDefaultSymbol->getName())
5216 .toStringRef(Out&: Buf));
5217 Buf.clear();
5218 }
5219 }
5220
5221 if (SwitchedToDirectiveSection)
5222 OutStreamer->popSection();
5223
5224 if (FuncOverrideDefaultSymbols.empty())
5225 return;
5226
5227 // MSVC emits the symbols for the default variables pointing at the start of
5228 // the .data section, but doesn't actually allocate any space for them. LLVM
5229 // can't do this, so have all of the variables pointing at a single byte
5230 // instead.
5231 OutStreamer->switchSection(Section: OutContext.getObjectFileInfo()->getDataSection());
5232 for (MCSymbol *Symbol : FuncOverrideDefaultSymbols) {
5233 OutStreamer->emitLabel(Symbol);
5234 }
5235 OutStreamer->emitZeros(NumBytes: 1);
5236 OutStreamer->popSection();
5237}
5238
5239void AsmPrinter::emitCOFFFeatureSymbol(Module &M) {
5240 const Triple &TT = TM.getTargetTriple();
5241 assert(TT.isOSBinFormatCOFF());
5242
5243 // Emit an absolute @feat.00 symbol.
5244 MCSymbol *S = MMI->getContext().getOrCreateSymbol(Name: StringRef("@feat.00"));
5245 OutStreamer->beginCOFFSymbolDef(Symbol: S);
5246 OutStreamer->emitCOFFSymbolStorageClass(StorageClass: COFF::IMAGE_SYM_CLASS_STATIC);
5247 OutStreamer->emitCOFFSymbolType(Type: COFF::IMAGE_SYM_DTYPE_NULL);
5248 OutStreamer->endCOFFSymbolDef();
5249 int64_t Feat00Value = 0;
5250
5251 if (TT.getArch() == Triple::x86) {
5252 // According to the PE-COFF spec, the LSB of this value marks the object
5253 // for "registered SEH". This means that all SEH handler entry points
5254 // must be registered in .sxdata. Use of any unregistered handlers will
5255 // cause the process to terminate immediately. LLVM does not know how to
5256 // register any SEH handlers, so its object files should be safe.
5257 Feat00Value |= COFF::Feat00Flags::SafeSEH;
5258 }
5259
5260 if (M.getControlFlowGuardMode() == ControlFlowGuardMode::Enabled) {
5261 // Object is CFG-aware. Only set if we actually inserted the checks.
5262 Feat00Value |= COFF::Feat00Flags::GuardCF;
5263 }
5264
5265 if (M.getModuleFlag(Key: "ehcontguard")) {
5266 // Object also has EHCont.
5267 Feat00Value |= COFF::Feat00Flags::GuardEHCont;
5268 }
5269
5270 if (M.getModuleFlag(Key: "ms-kernel")) {
5271 // Object is compiled with /kernel.
5272 Feat00Value |= COFF::Feat00Flags::Kernel;
5273 }
5274
5275 OutStreamer->emitSymbolAttribute(Symbol: S, Attribute: MCSA_Global);
5276 OutStreamer->emitAssignment(
5277 Symbol: S, Value: MCConstantExpr::create(Value: Feat00Value, Ctx&: MMI->getContext()));
5278}
5279
5280namespace llvm {
5281namespace {
5282MachineFunctionAnalysisManager &getMFAM(Module &M, ModuleAnalysisManager &MAM,
5283 MachineFunction &MF) {
5284 FunctionAnalysisManager &FAM =
5285 MAM.getResult<FunctionAnalysisManagerModuleProxy>(IR&: M).getManager();
5286 MachineFunctionAnalysisManager &MFAM =
5287 FAM.getResult<MachineFunctionAnalysisManagerFunctionProxy>(
5288 IR&: MF.getFunction())
5289 .getManager();
5290 return MFAM;
5291}
5292} // anonymous namespace
5293
5294void setupModuleAsmPrinter(Module &M, ModuleAnalysisManager &MAM,
5295 AsmPrinter &AsmPrinter) {
5296 MachineModuleInfo &MMI = MAM.getResult<MachineModuleAnalysis>(IR&: M).getMMI();
5297 AsmPrinter.GetMMI = [&MMI]() { return &MMI; };
5298 AsmPrinter.MMI = &MMI;
5299 AsmPrinter.GetORE = [&MAM, &M](MachineFunction &MF) {
5300 return &getMFAM(M, MAM, MF)
5301 .getResult<MachineOptimizationRemarkEmitterAnalysis>(IR&: MF);
5302 };
5303 AsmPrinter.GetMDT = [&MAM, &M](MachineFunction &MF) {
5304 return &getMFAM(M, MAM, MF).getResult<MachineDominatorTreeAnalysis>(IR&: MF);
5305 };
5306 AsmPrinter.GetMLI = [&MAM, &M](MachineFunction &MF) {
5307 return &getMFAM(M, MAM, MF).getResult<MachineLoopAnalysis>(IR&: MF);
5308 };
5309 // TODO(boomanaiden154): Get GC working with the new pass manager.
5310 AsmPrinter.BeginGCAssembly = [](Module &M) {};
5311 AsmPrinter.FinishGCAssembly = [](Module &M) {};
5312 AsmPrinter.EmitStackMaps = [](Module &M) {};
5313 AsmPrinter.AssertDebugEHFinalized = []() {};
5314}
5315
5316void setupMachineFunctionAsmPrinter(MachineFunctionAnalysisManager &MFAM,
5317 MachineFunction &MF,
5318 AsmPrinter &AsmPrinter) {
5319 const ModuleAnalysisManagerMachineFunctionProxy::Result &MAMProxy =
5320 MFAM.getResult<ModuleAnalysisManagerMachineFunctionProxy>(IR&: MF);
5321 MachineModuleInfo &MMI =
5322 MAMProxy
5323 .getCachedResult<MachineModuleAnalysis>(IR&: *MF.getFunction().getParent())
5324 ->getMMI();
5325 AsmPrinter.GetMMI = [&MMI]() { return &MMI; };
5326 AsmPrinter.MMI = &MMI;
5327 AsmPrinter.GetORE = [&MFAM](MachineFunction &MF) {
5328 return &MFAM.getResult<MachineOptimizationRemarkEmitterAnalysis>(IR&: MF);
5329 };
5330 AsmPrinter.GetMDT = [&MFAM](MachineFunction &MF) {
5331 return &MFAM.getResult<MachineDominatorTreeAnalysis>(IR&: MF);
5332 };
5333 AsmPrinter.GetMLI = [&MFAM](MachineFunction &MF) {
5334 return &MFAM.getResult<MachineLoopAnalysis>(IR&: MF);
5335 };
5336 // TODO(boomanaiden154): Get GC working with the new pass manager.
5337 AsmPrinter.BeginGCAssembly = [](Module &M) {};
5338 AsmPrinter.FinishGCAssembly = [](Module &M) {};
5339 AsmPrinter.EmitStackMaps = [](Module &M) {};
5340 AsmPrinter.AssertDebugEHFinalized = []() {};
5341}
5342
5343AnalysisKey AsmPrinterAnalysis::Key;
5344
5345} // namespace llvm
5346