1//===- llvm/CodeGen/DwarfCompileUnit.cpp - Dwarf Compile Units ------------===//
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 contains support for constructing a dwarf compile unit.
10//
11//===----------------------------------------------------------------------===//
12
13#include "DwarfCompileUnit.h"
14#include "AddressPool.h"
15#include "DwarfExpression.h"
16#include "llvm/ADT/STLExtras.h"
17#include "llvm/ADT/SmallString.h"
18#include "llvm/BinaryFormat/Dwarf.h"
19#include "llvm/CodeGen/AsmPrinter.h"
20#include "llvm/CodeGen/DIE.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/CodeGen/MachineInstr.h"
23#include "llvm/CodeGen/TargetFrameLowering.h"
24#include "llvm/CodeGen/TargetRegisterInfo.h"
25#include "llvm/CodeGen/TargetSubtargetInfo.h"
26#include "llvm/IR/DataLayout.h"
27#include "llvm/IR/DebugInfo.h"
28#include "llvm/IR/GlobalVariable.h"
29#include "llvm/MC/MCAsmInfo.h"
30#include "llvm/MC/MCSection.h"
31#include "llvm/MC/MCStreamer.h"
32#include "llvm/MC/MCSymbol.h"
33#include "llvm/MC/MCSymbolWasm.h"
34#include "llvm/MC/MachineLocation.h"
35#include "llvm/Support/CommandLine.h"
36#include "llvm/Target/TargetLoweringObjectFile.h"
37#include "llvm/Target/TargetMachine.h"
38#include <optional>
39#include <string>
40#include <utility>
41
42using namespace llvm;
43
44/// Query value using AddLinkageNamesToDeclCallOriginsForTuning.
45static cl::opt<cl::boolOrDefault> AddLinkageNamesToDeclCallOrigins(
46 "add-linkage-names-to-declaration-call-origins", cl::Hidden,
47 cl::desc("Add DW_AT_linkage_name to function declaration DIEs "
48 "referenced by DW_AT_call_origin attributes. Enabled by default "
49 "for -gsce debugger tuning."));
50
51static cl::opt<bool> EmitFuncLineTableOffsetsOption(
52 "emit-func-debug-line-table-offsets", cl::Hidden,
53 cl::desc("Include line table offset in function's debug info and emit end "
54 "sequence after each function's line data."),
55 cl::init(Val: false));
56
57static bool AddLinkageNamesToDeclCallOriginsForTuning(const DwarfDebug *DD) {
58 bool EnabledByDefault = DD->tuneForSCE();
59 if (EnabledByDefault)
60 return AddLinkageNamesToDeclCallOrigins != cl::boolOrDefault::BOU_FALSE;
61 return AddLinkageNamesToDeclCallOrigins == cl::boolOrDefault::BOU_TRUE;
62}
63
64static dwarf::Tag GetCompileUnitType(UnitKind Kind, DwarfDebug *DW) {
65
66 // According to DWARF Debugging Information Format Version 5,
67 // 3.1.2 Skeleton Compilation Unit Entries:
68 // "When generating a split DWARF object file (see Section 7.3.2
69 // on page 187), the compilation unit in the .debug_info section
70 // is a "skeleton" compilation unit with the tag DW_TAG_skeleton_unit"
71 if (DW->getDwarfVersion() >= 5 && Kind == UnitKind::Skeleton)
72 return dwarf::DW_TAG_skeleton_unit;
73
74 return dwarf::DW_TAG_compile_unit;
75}
76
77DwarfCompileUnit::DwarfCompileUnit(unsigned UID, const DICompileUnit *Node,
78 AsmPrinter *A, DwarfDebug *DW,
79 DwarfFile *DWU, UnitKind Kind)
80 : DwarfUnit(GetCompileUnitType(Kind, DW), Node, A, DW, DWU, UID) {
81 insertDIE(Desc: Node, D: &getUnitDie());
82 MacroLabelBegin = Asm->createTempSymbol(Name: "cu_macro_begin");
83 assert(CUNode);
84 for (auto *GVE : CUNode->getGlobalVariables())
85 if (auto *GV = GVE->getVariable())
86 GlobalVarScopes.insert(Ptr: GV->getScope());
87}
88
89/// addLabelAddress - Add a dwarf label attribute data and value using
90/// DW_FORM_addr or DW_FORM_GNU_addr_index.
91void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
92 const MCSymbol *Label) {
93 if ((Skeleton || !DD->useSplitDwarf()) && Label)
94 DD->addArangeLabel(SCU: SymbolCU(this, Label));
95
96 // Don't use the address pool in non-fission or in the skeleton unit itself.
97 if ((!DD->useSplitDwarf() || !Skeleton) && DD->getDwarfVersion() < 5)
98 return addLocalLabelAddress(Die, Attribute, Label);
99
100 bool UseAddrOffsetFormOrExpressions =
101 DD->useAddrOffsetForm() || DD->useAddrOffsetExpressions();
102
103 const MCSymbol *Base = nullptr;
104 if (Label->isInSection() && UseAddrOffsetFormOrExpressions)
105 Base = DD->getSectionLabel(S: &Label->getSection());
106
107 if (!Base || Base == Label) {
108 unsigned idx = DD->getAddressPool().getIndex(Sym: Label);
109 addAttribute(Die, Attribute,
110 Form: DD->getDwarfVersion() >= 5 ? dwarf::DW_FORM_addrx
111 : dwarf::DW_FORM_GNU_addr_index,
112 Value: DIEInteger(idx));
113 return;
114 }
115
116 // Could be extended to work with DWARFv4 Split DWARF if that's important for
117 // someone. In that case DW_FORM_data would be used.
118 assert(DD->getDwarfVersion() >= 5 &&
119 "Addr+offset expressions are only valuable when using debug_addr (to "
120 "reduce relocations) available in DWARFv5 or higher");
121 if (DD->useAddrOffsetExpressions()) {
122 auto *Loc = new (DIEValueAllocator) DIEBlock();
123 addPoolOpAddress(Die&: *Loc, Label);
124 addBlock(Die, Attribute, Form: dwarf::DW_FORM_exprloc, Block: Loc);
125 } else
126 addAttribute(Die, Attribute, Form: dwarf::DW_FORM_LLVM_addrx_offset,
127 Value: new (DIEValueAllocator) DIEAddrOffset(
128 DD->getAddressPool().getIndex(Sym: Base), Label, Base));
129}
130
131void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
132 dwarf::Attribute Attribute,
133 const MCSymbol *Label) {
134 if (Label)
135 addAttribute(Die, Attribute, Form: dwarf::DW_FORM_addr, Value: DIELabel(Label));
136 else
137 addAttribute(Die, Attribute, Form: dwarf::DW_FORM_addr, Value: DIEInteger(0));
138}
139
140unsigned DwarfCompileUnit::getOrCreateSourceID(const DIFile *File) {
141 // If we print assembly, we can't separate .file entries according to
142 // compile units. Thus all files will belong to the default compile unit.
143
144 // FIXME: add a better feature test than hasRawTextSupport. Even better,
145 // extend .file to support this.
146 unsigned CUID = Asm->OutStreamer->hasRawTextSupport() ? 0 : getUniqueID();
147 if (!File)
148 return Asm->OutStreamer->emitDwarfFileDirective(FileNo: 0, Directory: "", Filename: "", Checksum: std::nullopt,
149 Source: std::nullopt, CUID);
150
151 if (LastFile != File) {
152 LastFile = File;
153 LastFileID = Asm->OutStreamer->emitDwarfFileDirective(
154 FileNo: 0, Directory: File->getDirectory(), Filename: File->getFilename(), Checksum: DD->getMD5AsBytes(File),
155 Source: File->getSource(), CUID);
156 }
157 return LastFileID;
158}
159
160DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
161 const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
162 // Check for pre-existence.
163 if (DIE *Die = getDIE(D: GV))
164 return Die;
165
166 assert(GV);
167
168 auto *GVContext = GV->getScope();
169 const DIType *GTy = GV->getType();
170
171 auto *CB = GVContext ? dyn_cast<DICommonBlock>(Val: GVContext) : nullptr;
172 DIE *ContextDIE = CB ? getOrCreateCommonBlock(CB, GlobalExprs)
173 : getOrCreateContextDIE(Ty: GVContext);
174
175 // Add to map.
176 DIE *VariableDIE = &createAndAddDIE(Tag: GV->getTag(), Parent&: *ContextDIE, N: GV);
177 DIScope *DeclContext;
178 if (auto *SDMDecl = GV->getStaticDataMemberDeclaration()) {
179 DeclContext = SDMDecl->getScope();
180 assert(SDMDecl->isStaticMember() && "Expected static member decl");
181 assert(GV->isDefinition());
182 // We need the declaration DIE that is in the static member's class.
183 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(DT: SDMDecl);
184 addDIEEntry(Die&: *VariableDIE, Attribute: dwarf::DW_AT_specification, Entry&: *VariableSpecDIE);
185 // If the global variable's type is different from the one in the class
186 // member type, assume that it's more specific and also emit it.
187 if (GTy != SDMDecl->getBaseType())
188 addType(Entity&: *VariableDIE, Ty: GTy);
189 } else {
190 DeclContext = GV->getScope();
191 // Add name and type.
192 StringRef DisplayName = GV->getDisplayName();
193 if (!DisplayName.empty())
194 addString(Die&: *VariableDIE, Attribute: dwarf::DW_AT_name, Str: GV->getDisplayName());
195 if (GTy)
196 addType(Entity&: *VariableDIE, Ty: GTy);
197
198 // Add scoping info.
199 if (!GV->isLocalToUnit())
200 addFlag(Die&: *VariableDIE, Attribute: dwarf::DW_AT_external);
201
202 // Add line number info.
203 addSourceLine(Die&: *VariableDIE, G: GV);
204 }
205
206 if (!GV->isDefinition())
207 addFlag(Die&: *VariableDIE, Attribute: dwarf::DW_AT_declaration);
208 else
209 addGlobalName(Name: GV->getName(), Die: *VariableDIE, Context: DeclContext);
210
211 addAnnotation(Buffer&: *VariableDIE, Annotations: GV->getAnnotations());
212
213 if (uint32_t AlignInBytes = GV->getAlignInBytes())
214 addUInt(Die&: *VariableDIE, Attribute: dwarf::DW_AT_alignment, Form: dwarf::DW_FORM_udata,
215 Integer: AlignInBytes);
216
217 if (MDTuple *TP = GV->getTemplateParams())
218 addTemplateParams(Buffer&: *VariableDIE, TParams: DINodeArray(TP));
219
220 // Add location.
221 addLocationAttribute(ToDIE: VariableDIE, GV, GlobalExprs);
222
223 return VariableDIE;
224}
225
226void DwarfCompileUnit::addLocationAttribute(
227 DIE *VariableDIE, const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
228 bool addToAccelTable = false;
229 DIELoc *Loc = nullptr;
230 std::optional<unsigned> TargetAddrSpace;
231 std::unique_ptr<DIEDwarfExpression> DwarfExpr;
232 const GlobalVariable *LastGlobal = nullptr;
233 for (const auto &GE : GlobalExprs) {
234 const GlobalVariable *Global = GE.Var;
235 const DIExpression *Expr = GE.Expr;
236
237 // For compatibility with DWARF 3 and earlier,
238 // DW_AT_location(DW_OP_constu, X, DW_OP_stack_value) or
239 // DW_AT_location(DW_OP_consts, X, DW_OP_stack_value) becomes
240 // DW_AT_const_value(X).
241 if (GlobalExprs.size() == 1 && Expr && Expr->isConstant()) {
242 addToAccelTable = true;
243 addConstantValue(
244 Die&: *VariableDIE,
245 Unsigned: DIExpression::SignedOrUnsignedConstant::UnsignedConstant ==
246 *Expr->isConstant(),
247 Val: Expr->getElement(I: 1));
248 break;
249 }
250
251 // We cannot describe the location of dllimport'd variables: the
252 // computation of their address requires loads from the IAT.
253 if (Global && Global->hasDLLImportStorageClass())
254 continue;
255
256 // Nothing to describe without address or constant.
257 if (!Global && (!Expr || !Expr->isConstant()))
258 continue;
259
260 if (Global && Global->isThreadLocal() &&
261 !Asm->getObjFileLowering().supportDebugThreadLocalLocation())
262 continue;
263
264 if (!Loc) {
265 addToAccelTable = true;
266 Loc = new (DIEValueAllocator) DIELoc;
267 DwarfExpr = std::make_unique<DIEDwarfExpression>(args&: *Asm, args&: *this, args&: *Loc);
268 }
269
270 if (Expr) {
271 Expr = DD->adjustExpressionForTarget(Expr, TargetAddrSpace);
272 DwarfExpr->addFragmentOffset(Expr);
273 }
274
275 if (Global) {
276 const MCSymbol *Sym = Asm->getSymbol(GV: Global);
277 // 16-bit platforms like MSP430 and AVR take this path, so sink this
278 // assert to platforms that use it.
279 auto GetPointerSizedFormAndOp = [this]() {
280 unsigned PointerSize = Asm->MAI.getCodePointerSize();
281 assert((PointerSize == 4 || PointerSize == 8) &&
282 "Add support for other sizes if necessary");
283 struct FormAndOp {
284 dwarf::Form Form;
285 dwarf::LocationAtom Op;
286 };
287 return PointerSize == 4
288 ? FormAndOp{.Form: dwarf::DW_FORM_data4, .Op: dwarf::DW_OP_const4u}
289 : FormAndOp{.Form: dwarf::DW_FORM_data8, .Op: dwarf::DW_OP_const8u};
290 };
291 if (Global->isThreadLocal()) {
292 if (Asm->TM.getTargetTriple().isWasm()) {
293 // FIXME This is not guaranteed, but in practice, in static linking,
294 // if present, __tls_base's index is 1. This doesn't hold for dynamic
295 // linking, so TLS variables used in dynamic linking won't have
296 // correct debug info for now. See
297 // https://github.com/llvm/llvm-project/blob/19afbfe33156d211fa959dadeea46cd17b9c723c/lld/wasm/Driver.cpp#L786-L823
298 addWasmRelocBaseGlobal(Loc, GlobalName: "__tls_base", GlobalIndex: 1);
299 addOpAddress(Die&: *Loc, Sym);
300 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_plus);
301 } else if (Asm->TM.useEmulatedTLS()) {
302 // TODO: add debug info for emulated thread local mode.
303 } else {
304 // FIXME: Make this work with -gsplit-dwarf.
305 // Based on GCC's support for TLS:
306 if (!DD->useSplitDwarf()) {
307 auto FormAndOp = GetPointerSizedFormAndOp();
308 // 1) Start with a constNu of the appropriate pointer size
309 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: FormAndOp.Op);
310 // 2) containing the (relocated) offset of the TLS variable
311 // within the module's TLS block.
312 addExpr(Die&: *Loc, Form: FormAndOp.Form,
313 Expr: Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
314 } else {
315 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_GNU_const_index);
316 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_udata,
317 Integer: DD->getAddressPool().getIndex(Sym, /* TLS */ true));
318 }
319 // 3) followed by an OP to make the debugger do a TLS lookup.
320 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1,
321 Integer: DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
322 : dwarf::DW_OP_form_tls_address);
323 }
324 } else if (Asm->TM.getTargetTriple().isWasm() &&
325 Asm->TM.getRelocationModel() == Reloc::PIC_) {
326 // FIXME This is not guaranteed, but in practice, if present,
327 // __memory_base's index is 1. See
328 // https://github.com/llvm/llvm-project/blob/19afbfe33156d211fa959dadeea46cd17b9c723c/lld/wasm/Driver.cpp#L786-L823
329 addWasmRelocBaseGlobal(Loc, GlobalName: "__memory_base", GlobalIndex: 1);
330 addOpAddress(Die&: *Loc, Sym);
331 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_plus);
332 } else if ((Asm->TM.getRelocationModel() == Reloc::RWPI ||
333 Asm->TM.getRelocationModel() == Reloc::ROPI_RWPI) &&
334 !Asm->getObjFileLowering()
335 .getKindForGlobal(GO: Global, TM: Asm->TM)
336 .isReadOnly()) {
337 auto FormAndOp = GetPointerSizedFormAndOp();
338 // Constant
339 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: FormAndOp.Op);
340 // Relocation offset
341 addExpr(Die&: *Loc, Form: FormAndOp.Form,
342 Expr: Asm->getObjFileLowering().getIndirectSymViaRWPI(Sym));
343 // Base register
344 Register BaseReg = Asm->getObjFileLowering().getStaticBase();
345 unsigned DwarfBaseReg =
346 Asm->TM.getMCRegisterInfo().getDwarfRegNum(Reg: BaseReg, isEH: false);
347 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_breg0 + DwarfBaseReg);
348 // Offset from base register
349 addSInt(Die&: *Loc, Form: dwarf::DW_FORM_sdata, Integer: 0);
350 // Operation
351 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_plus);
352 } else {
353 DD->addArangeLabel(SCU: SymbolCU(this, Sym));
354 addOpAddress(Die&: *Loc, Sym);
355 }
356 LastGlobal = Global;
357 }
358 // Global variables attached to symbols are memory locations.
359 // It would be better if this were unconditional, but malformed input that
360 // mixes non-fragments and fragments for the same variable is too expensive
361 // to detect in the verifier.
362 if (DwarfExpr->isUnknownLocation())
363 DwarfExpr->setMemoryLocationKind();
364 DwarfExpr->addExpression(Expr);
365 }
366 DD->addTargetVariableAttributes(CU&: *this, Die&: *VariableDIE, TargetAddrSpace,
367 VarLocKind: DwarfDebug::VariableLocationKind::Global,
368 GV: LastGlobal);
369 if (Loc)
370 addBlock(Die&: *VariableDIE, Attribute: dwarf::DW_AT_location, Loc: DwarfExpr->finalize());
371
372 if (DD->useAllLinkageNames())
373 addLinkageName(Die&: *VariableDIE, LinkageName: GV->getLinkageName());
374
375 if (addToAccelTable) {
376 DD->addAccelName(Unit: *this, NameTableKind: CUNode->getNameTableKind(), Name: GV->getName(),
377 Die: *VariableDIE);
378
379 // If the linkage name is different than the name, go ahead and output
380 // that as well into the name table.
381 if (GV->getLinkageName() != "" && GV->getName() != GV->getLinkageName() &&
382 DD->useAllLinkageNames())
383 DD->addAccelName(Unit: *this, NameTableKind: CUNode->getNameTableKind(), Name: GV->getLinkageName(),
384 Die: *VariableDIE);
385 }
386}
387
388DIE *DwarfCompileUnit::getOrCreateCommonBlock(
389 const DICommonBlock *CB, ArrayRef<GlobalExpr> GlobalExprs) {
390 // Check for pre-existence.
391 if (DIE *NDie = getDIE(D: CB))
392 return NDie;
393 DIE *ContextDIE = getOrCreateContextDIE(Ty: CB->getScope());
394 DIE &NDie = createAndAddDIE(Tag: dwarf::DW_TAG_common_block, Parent&: *ContextDIE, N: CB);
395 StringRef Name = CB->getName().empty() ? "_BLNK_" : CB->getName();
396 addString(Die&: NDie, Attribute: dwarf::DW_AT_name, Str: Name);
397 addGlobalName(Name, Die: NDie, Context: CB->getScope());
398 if (CB->getFile())
399 addSourceLine(Die&: NDie, Line: CB->getLineNo(), /*Column*/ 0, File: CB->getFile());
400 if (DIGlobalVariable *V = CB->getDecl())
401 getCU().addLocationAttribute(VariableDIE: &NDie, GV: V, GlobalExprs);
402 return &NDie;
403}
404
405void DwarfCompileUnit::addRange(RangeSpan Range) {
406 DD->insertSectionLabel(S: Range.Begin);
407
408 auto *PrevCU = DD->getPrevCU();
409 bool SameAsPrevCU = this == PrevCU;
410 DD->setPrevCU(this);
411 // If we have no current ranges just add the range and return, otherwise,
412 // check the current section and CU against the previous section and CU we
413 // emitted into and the subprogram was contained within. If these are the
414 // same then extend our current range, otherwise add this as a new range.
415 if (CURanges.empty() || !SameAsPrevCU ||
416 (&CURanges.back().End->getSection() !=
417 &Range.End->getSection())) {
418 // Before a new range is added, always terminate the prior line table.
419 if (PrevCU)
420 DD->terminateLineTable(CU: PrevCU);
421 CURanges.push_back(Elt: Range);
422 return;
423 }
424
425 CURanges.back().End = Range.End;
426}
427
428void DwarfCompileUnit::initStmtList() {
429 if (CUNode->isDebugDirectivesOnly())
430 return;
431
432 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
433 if (DD->useSectionsAsReferences()) {
434 LineTableStartSym = TLOF.getDwarfLineSection()->getBeginSymbol();
435 } else {
436 LineTableStartSym =
437 Asm->OutStreamer->getDwarfLineTableSymbol(CUID: getUniqueID());
438 }
439
440 // DW_AT_stmt_list is a offset of line number information for this
441 // compile unit in debug_line section. For split dwarf this is
442 // left in the skeleton CU and so not included.
443 // The line table entries are not always emitted in assembly, so it
444 // is not okay to use line_table_start here.
445 addSectionLabel(Die&: getUnitDie(), Attribute: dwarf::DW_AT_stmt_list, Label: LineTableStartSym,
446 Sec: TLOF.getDwarfLineSection()->getBeginSymbol());
447}
448
449void DwarfCompileUnit::applyStmtList(DIE &D) {
450 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
451 addSectionLabel(Die&: D, Attribute: dwarf::DW_AT_stmt_list, Label: LineTableStartSym,
452 Sec: TLOF.getDwarfLineSection()->getBeginSymbol());
453}
454
455void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
456 const MCSymbol *End) {
457 assert(Begin && "Begin label should not be null!");
458 assert(End && "End label should not be null!");
459 assert(Begin->isDefined() && "Invalid starting label");
460 assert(End->isDefined() && "Invalid end label");
461
462 addLabelAddress(Die&: D, Attribute: dwarf::DW_AT_low_pc, Label: Begin);
463 if (DD->getDwarfVersion() >= 4 &&
464 (!isDwoUnit() || !llvm::isRangeRelaxable(Begin, End))) {
465 addLabelDelta(Die&: D, Attribute: dwarf::DW_AT_high_pc, Hi: End, Lo: Begin);
466 return;
467 }
468 addLabelAddress(Die&: D, Attribute: dwarf::DW_AT_high_pc, Label: End);
469}
470
471// Add info for Wasm-global-based relocation.
472// 'GlobalIndex' is used for split dwarf, which currently relies on a few
473// assumptions that are not guaranteed in a formal way but work in practice.
474void DwarfCompileUnit::addWasmRelocBaseGlobal(DIELoc *Loc, StringRef GlobalName,
475 uint64_t GlobalIndex) {
476 // FIXME: duplicated from Target/WebAssembly/WebAssembly.h
477 // don't want to depend on target specific headers in this code?
478 const unsigned TI_GLOBAL_RELOC = 3;
479 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
480 auto *Sym =
481 static_cast<MCSymbolWasm *>(Asm->GetExternalSymbolSymbol(Sym: GlobalName));
482 // FIXME: this repeats what WebAssemblyMCInstLower::
483 // GetExternalSymbolSymbol does, since if there's no code that
484 // refers to this symbol, we have to set it here.
485 Sym->setType(wasm::WASM_SYMBOL_TYPE_GLOBAL);
486 Sym->setGlobalType(wasm::WasmGlobalType{
487 .Type: static_cast<uint8_t>(PointerSize == 4 ? wasm::WASM_TYPE_I32
488 : wasm::WASM_TYPE_I64),
489 .Mutable: true});
490 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_WASM_location);
491 addSInt(Die&: *Loc, Form: dwarf::DW_FORM_sdata, Integer: TI_GLOBAL_RELOC);
492 if (!isDwoUnit()) {
493 addLabel(Die&: *Loc, Form: dwarf::DW_FORM_data4, Label: Sym);
494 } else {
495 // FIXME: when writing dwo, we need to avoid relocations. Probably
496 // the "right" solution is to treat globals the way func and data
497 // symbols are (with entries in .debug_addr).
498 // For now we hardcode the indices in the callsites. Global indices are not
499 // fixed, but in practice a few are fixed; for example, __stack_pointer is
500 // always index 0.
501 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data4, Integer: GlobalIndex);
502 }
503}
504
505// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
506// and DW_AT_high_pc attributes. If there are global variables in this
507// scope then create and insert DIEs for these variables.
508DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP,
509 const Function &F,
510 MCSymbol *LineTableSym) {
511 DIE *SPDie = getOrCreateSubprogramDIE(SP, F: &F, Minimal: includeMinimalInlineScopes());
512 SmallVector<RangeSpan, 2> BB_List;
513 // If basic block sections are on, ranges for each basic block section has
514 // to be emitted separately.
515 for (const auto &R : Asm->MBBSectionRanges)
516 BB_List.push_back(Elt: {.Begin: R.second.BeginLabel, .End: R.second.EndLabel});
517
518 attachRangesOrLowHighPC(D&: *SPDie, Ranges: BB_List);
519
520 if (DD->useAppleExtensionAttributes() &&
521 !DD->getCurrentFunction()->disableFramePointerElim())
522 addFlag(Die&: *SPDie, Attribute: dwarf::DW_AT_APPLE_omit_frame_ptr);
523
524 if (emitFuncLineTableOffsets() && LineTableSym) {
525 MCSymbol *Symbol =
526 Asm->getObjFileLowering().getDwarfLineSection()->getBeginSymbol();
527 addSectionLabel(Die&: *SPDie, Attribute: dwarf::DW_AT_LLVM_stmt_sequence, Label: LineTableSym,
528 Sec: Symbol);
529 }
530
531 // Only include DW_AT_frame_base in full debug info
532 if (!includeMinimalInlineScopes()) {
533 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
534 TargetFrameLowering::DwarfFrameBase FrameBase =
535 TFI->getDwarfFrameBase(MF: *Asm->MF);
536 switch (FrameBase.Kind) {
537 case TargetFrameLowering::DwarfFrameBase::Register: {
538 if (Register::isPhysicalRegister(Reg: FrameBase.Location.Reg)) {
539 MachineLocation Location(FrameBase.Location.Reg);
540 addAddress(Die&: *SPDie, Attribute: dwarf::DW_AT_frame_base, Location);
541 }
542 break;
543 }
544 case TargetFrameLowering::DwarfFrameBase::CFA: {
545 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
546 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_call_frame_cfa);
547 if (FrameBase.Location.Offset != 0) {
548 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_consts);
549 addSInt(Die&: *Loc, Form: dwarf::DW_FORM_sdata, Integer: FrameBase.Location.Offset);
550 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_plus);
551 }
552 addBlock(Die&: *SPDie, Attribute: dwarf::DW_AT_frame_base, Loc);
553 break;
554 }
555 case TargetFrameLowering::DwarfFrameBase::WasmFrameBase: {
556 // FIXME: duplicated from Target/WebAssembly/WebAssembly.h
557 const unsigned TI_GLOBAL_RELOC = 3;
558 if (FrameBase.Location.WasmLoc.Kind == TI_GLOBAL_RELOC) {
559 // These need to be relocatable.
560 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
561 assert(FrameBase.Location.WasmLoc.Index == 0); // Only SP so far.
562 // For now, since we only ever use index 0, this should work as-is.
563 addWasmRelocBaseGlobal(Loc, GlobalName: "__stack_pointer",
564 GlobalIndex: FrameBase.Location.WasmLoc.Index);
565 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: dwarf::DW_OP_stack_value);
566 addBlock(Die&: *SPDie, Attribute: dwarf::DW_AT_frame_base, Loc);
567 } else {
568 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
569 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
570 DIExpressionCursor Cursor({});
571 DwarfExpr.addWasmLocation(Index: FrameBase.Location.WasmLoc.Kind,
572 Offset: FrameBase.Location.WasmLoc.Index);
573 DwarfExpr.addExpression(Expr: std::move(Cursor));
574 addBlock(Die&: *SPDie, Attribute: dwarf::DW_AT_frame_base, Loc: DwarfExpr.finalize());
575 }
576 break;
577 }
578 }
579 }
580
581 // Add name to the name table, we do this here because we're guaranteed
582 // to have concrete versions of our DW_TAG_subprogram nodes.
583 DD->addSubprogramNames(Unit: *this, NameTableKind: CUNode->getNameTableKind(), SP, Die&: *SPDie);
584
585 return *SPDie;
586}
587
588// Construct a DIE for this scope.
589void DwarfCompileUnit::constructScopeDIE(LexicalScope *Scope,
590 DIE &ParentScopeDIE) {
591 if (!Scope || !Scope->getScopeNode())
592 return;
593
594 auto *DS = Scope->getScopeNode();
595
596 assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
597 "Only handle inlined subprograms here, use "
598 "constructSubprogramScopeDIE for non-inlined "
599 "subprograms");
600
601 // Emit inlined subprograms.
602 if (Scope->getParent() && isa<DISubprogram>(Val: DS)) {
603 DIE *ScopeDIE = constructInlinedScopeDIE(Scope, ParentScopeDIE);
604 assert(ScopeDIE && "Scope DIE should not be null.");
605 createAndAddScopeChildren(Scope, ScopeDIE&: *ScopeDIE);
606 return;
607 }
608
609 // Early exit when we know the scope DIE is going to be null.
610 if (DD->isLexicalScopeDIENull(Scope))
611 return;
612
613 // Emit lexical blocks.
614 DIE *ScopeDIE = getOrCreateLexicalBlockDIE(Scope, ParentDIE&: ParentScopeDIE);
615 assert(ScopeDIE && "Scope DIE should not be null.");
616
617 createAndAddScopeChildren(Scope, ScopeDIE&: *ScopeDIE);
618}
619
620void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
621 SmallVector<RangeSpan, 2> Range) {
622
623 HasRangeLists = true;
624
625 // Add the range list to the set of ranges to be emitted.
626 auto IndexAndList =
627 (DD->getDwarfVersion() < 5 && Skeleton ? Skeleton->DU : DU)
628 ->addRange(CU: *(Skeleton ? Skeleton : this), R: std::move(Range));
629
630 uint32_t Index = IndexAndList.first;
631 auto &List = *IndexAndList.second;
632
633 // Under fission, ranges are specified by constant offsets relative to the
634 // CU's DW_AT_GNU_ranges_base.
635 // FIXME: For DWARF v5, do not generate the DW_AT_ranges attribute under
636 // fission until we support the forms using the .debug_addr section
637 // (DW_RLE_startx_endx etc.).
638 if (DD->getDwarfVersion() >= 5)
639 addUInt(Die&: ScopeDIE, Attribute: dwarf::DW_AT_ranges, Form: dwarf::DW_FORM_rnglistx, Integer: Index);
640 else {
641 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
642 const MCSymbol *RangeSectionSym =
643 TLOF.getDwarfRangesSection()->getBeginSymbol();
644 addSectionLabel(Die&: ScopeDIE, Attribute: dwarf::DW_AT_ranges, Label: List.Label, Sec: RangeSectionSym);
645 }
646}
647
648void DwarfCompileUnit::attachRangesOrLowHighPC(
649 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
650 assert(!Ranges.empty());
651 if (!DD->useRangesSection() ||
652 (Ranges.size() == 1 &&
653 (!DD->alwaysUseRanges(*this) ||
654 DD->getSectionLabel(S: &Ranges.front().Begin->getSection()) ==
655 Ranges.front().Begin))) {
656 const RangeSpan &Front = Ranges.front();
657 const RangeSpan &Back = Ranges.back();
658 attachLowHighPC(D&: Die, Begin: Front.Begin, End: Back.End);
659 } else
660 addScopeRangeList(ScopeDIE&: Die, Range: std::move(Ranges));
661}
662
663void DwarfCompileUnit::attachRangesOrLowHighPC(
664 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
665 SmallVector<RangeSpan, 2> List;
666 List.reserve(N: Ranges.size());
667 for (const InsnRange &R : Ranges) {
668 auto *BeginLabel = DD->getLabelBeforeInsn(MI: R.first);
669 auto *EndLabel = DD->getLabelAfterInsn(MI: R.second);
670
671 const auto *BeginMBB = R.first->getParent();
672 const auto *EndMBB = R.second->getParent();
673
674 const auto *MBB = BeginMBB;
675 // Basic block sections allows basic block subsets to be placed in unique
676 // sections. For each section, the begin and end label must be added to the
677 // list. If there is more than one range, debug ranges must be used.
678 // Otherwise, low/high PC can be used.
679 // FIXME: Debug Info Emission depends on block order and this assumes that
680 // the order of blocks will be frozen beyond this point.
681 do {
682 if (MBB->sameSection(MBB: EndMBB) || MBB->isEndSection()) {
683 auto MBBSectionRange = Asm->MBBSectionRanges[MBB->getSectionID()];
684 List.push_back(
685 Elt: {.Begin: MBB->sameSection(MBB: BeginMBB) ? BeginLabel
686 : MBBSectionRange.BeginLabel,
687 .End: MBB->sameSection(MBB: EndMBB) ? EndLabel : MBBSectionRange.EndLabel});
688 }
689 if (MBB->sameSection(MBB: EndMBB))
690 break;
691 MBB = MBB->getNextNode();
692 } while (true);
693 }
694 attachRangesOrLowHighPC(Die, Ranges: std::move(List));
695}
696
697DIE *DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope,
698 DIE &ParentScopeDIE) {
699 assert(Scope->getScopeNode());
700 auto *DS = Scope->getScopeNode();
701 auto *InlinedSP = getDISubprogram(Scope: DS);
702 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
703 // was inlined from another compile unit.
704 DIE *OriginDIE = getAbstractScopeDIEs()[InlinedSP];
705 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
706
707 auto ScopeDIE = DIE::get(Alloc&: DIEValueAllocator, Tag: dwarf::DW_TAG_inlined_subroutine);
708 ParentScopeDIE.addChild(Child: ScopeDIE);
709 addDIEEntry(Die&: *ScopeDIE, Attribute: dwarf::DW_AT_abstract_origin, Entry&: *OriginDIE);
710
711 attachRangesOrLowHighPC(Die&: *ScopeDIE, Ranges: Scope->getRanges());
712
713 // Add the call site information to the DIE.
714 const DILocation *IA = Scope->getInlinedAt();
715 addUInt(Die&: *ScopeDIE, Attribute: dwarf::DW_AT_call_file, Form: std::nullopt,
716 Integer: getOrCreateSourceID(File: IA->getFile()));
717 addUInt(Die&: *ScopeDIE, Attribute: dwarf::DW_AT_call_line, Form: std::nullopt, Integer: IA->getLine());
718 if (IA->getColumn())
719 addUInt(Die&: *ScopeDIE, Attribute: dwarf::DW_AT_call_column, Form: std::nullopt, Integer: IA->getColumn());
720 if (IA->getDiscriminator() && DD->getDwarfVersion() >= 4)
721 addUInt(Die&: *ScopeDIE, Attribute: dwarf::DW_AT_GNU_discriminator, Form: std::nullopt,
722 Integer: IA->getDiscriminator());
723
724 // Add name to the name table, we do this here because we're guaranteed
725 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
726 DD->addSubprogramNames(Unit: *this, NameTableKind: CUNode->getNameTableKind(), SP: InlinedSP,
727 Die&: *ScopeDIE);
728
729 return ScopeDIE;
730}
731
732DIE *DwarfCompileUnit::getOrCreateLexicalBlockDIE(LexicalScope *Scope,
733 DIE &ParentScopeDIE) {
734 if (DD->isLexicalScopeDIENull(Scope))
735 return nullptr;
736 const auto *DS = Scope->getScopeNode();
737
738 auto ScopeDIE = DIE::get(Alloc&: DIEValueAllocator, Tag: dwarf::DW_TAG_lexical_block);
739 ParentScopeDIE.addChild(Child: ScopeDIE);
740
741 if (Scope->isAbstractScope()) {
742 assert(!getAbstractScopeDIEs().count(DS) &&
743 "Abstract DIE for this scope exists!");
744 getAbstractScopeDIEs()[DS] = ScopeDIE;
745 return ScopeDIE;
746 }
747 if (!Scope->getInlinedAt()) {
748 assert(!LexicalBlockDIEs.count(DS) &&
749 "Concrete out-of-line DIE for this scope exists!");
750 LexicalBlockDIEs[DS] = ScopeDIE;
751 } else {
752 InlinedLocalScopeDIEs[DS].push_back(Elt: ScopeDIE);
753 }
754
755 attachRangesOrLowHighPC(Die&: *ScopeDIE, Ranges: Scope->getRanges());
756
757 return ScopeDIE;
758}
759
760DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV, bool Abstract) {
761 auto *VariableDie = DIE::get(Alloc&: DIEValueAllocator, Tag: DV.getTag());
762 insertDIE(Desc: DV.getVariable(), D: VariableDie);
763 DV.setDIE(*VariableDie);
764 // Abstract variables don't get common attributes later, so apply them now.
765 if (Abstract) {
766 applyCommonDbgVariableAttributes(Var: DV, VariableDie&: *VariableDie);
767 } else {
768 std::visit(
769 visitor: [&](const auto &V) {
770 applyConcreteDbgVariableAttributes(V, DV, *VariableDie);
771 },
772 variants&: DV.asVariant());
773 }
774 return VariableDie;
775}
776
777static const DIType *resolveTypeQualifiers(const DIType *Ty) {
778 while (const auto *DT = dyn_cast_or_null<DIDerivedType>(Val: Ty)) {
779 switch (DT->getTag()) {
780 case dwarf::DW_TAG_typedef:
781 case dwarf::DW_TAG_const_type:
782 case dwarf::DW_TAG_volatile_type:
783 case dwarf::DW_TAG_restrict_type:
784 case dwarf::DW_TAG_atomic_type:
785 Ty = DT->getBaseType();
786 continue;
787 default:
788 return Ty;
789 }
790 }
791 return Ty;
792}
793
794bool DwarfCompileUnit::emitImplicitPointerLocation(const Loc::Single &Single,
795 const DbgVariable &DV,
796 DIE &VariableDie) {
797 const DIExpression *Expr = Single.getExpr();
798 if (!Expr)
799 return false;
800
801 // Only handle the simple case where DW_OP_LLVM_implicit_pointer is the
802 // sole operation (or followed only by DW_OP_LLVM_fragment).
803 //
804 // Multi-level implicit pointers (e.g., int **pp where both levels are
805 // optimized away) would require stacking multiple implicit_pointer ops
806 // in one expression and unwinding them into a chain of artificial DIEs.
807 // This is left for future work.
808 //
809 // Location list support (Loc::Multi) is not yet handled.
810 auto ExprOps = Expr->expr_ops();
811 auto FirstOp = ExprOps.begin();
812 if (FirstOp == ExprOps.end() ||
813 FirstOp->getOp() != dwarf::DW_OP_LLVM_implicit_pointer)
814 return false;
815
816 if (DD->getDwarfVersion() < 4)
817 return false;
818
819 const DbgValueLoc &DVal = Single.getValueLoc();
820 if (DVal.isVariadic())
821 return false;
822
823 assert(!DVal.getLocEntries().empty() &&
824 "Non-variadic value must have one entry");
825 const DbgValueLocEntry &Entry = DVal.getLocEntries()[0];
826
827 // Resolve the variable's type, stripping qualifiers and typedefs,
828 // to find the pointer or reference type underneath.
829 // The verifier rejects cyclic type references, so this loop terminates.
830 const DIDerivedType *PtrTy =
831 dyn_cast_or_null<DIDerivedType>(Val: resolveTypeQualifiers(Ty: DV.getType()));
832 if (!PtrTy)
833 return false;
834
835 if (PtrTy->getTag() != dwarf::DW_TAG_pointer_type &&
836 PtrTy->getTag() != dwarf::DW_TAG_reference_type &&
837 PtrTy->getTag() != dwarf::DW_TAG_rvalue_reference_type)
838 return false;
839
840 const DIType *PointeeTy = PtrTy->getBaseType();
841
842 // Try to reuse an existing artificial DIE for constant integer values.
843 // This avoids duplicate DIEs when multiple pointer variables reference
844 // the same constant (e.g., after ArgumentPromotion promotes the same
845 // struct member for two different pointer parameters).
846 DIE *ArtificialDIEPtr = nullptr;
847 if (Entry.isInt() && PointeeTy) {
848 auto It = ImplicitPointerDIEs.find(Val: {PointeeTy, Entry.getInt()});
849 if (It != ImplicitPointerDIEs.end())
850 ArtificialDIEPtr = It->second;
851 }
852
853 if (!ArtificialDIEPtr) {
854 DIE &ProcDIE = createAndAddDIE(Tag: dwarf::DW_TAG_dwarf_procedure, Parent&: getUnitDie());
855
856 if (Entry.isLocation()) {
857 addAddress(Die&: ProcDIE, Attribute: dwarf::DW_AT_location, Location: Entry.getLoc());
858 } else if (Entry.isInt()) {
859 if (PointeeTy)
860 addConstantValue(Die&: ProcDIE, Val: Entry.getInt(), Ty: PointeeTy);
861 } else if (Entry.isConstantFP()) {
862 addConstantFPValue(Die&: ProcDIE, CFP: Entry.getConstantFP());
863 } else {
864 return false;
865 }
866
867 ArtificialDIEPtr = &ProcDIE;
868
869 // Cache constant entries for de-duplication.
870 if (Entry.isInt() && PointeeTy)
871 ImplicitPointerDIEs.insert(
872 KV: {{PointeeTy, Entry.getInt()}, ArtificialDIEPtr});
873 }
874
875 auto *Loc = new (DIEValueAllocator) DIELoc;
876
877 const unsigned ImplicitPtrOp = DD->getDwarfVersion() >= 5
878 ? dwarf::DW_OP_implicit_pointer
879 : dwarf::DW_OP_GNU_implicit_pointer;
880 addUInt(Block&: *Loc, Form: dwarf::DW_FORM_data1, Integer: ImplicitPtrOp);
881
882 Loc->addValue(Alloc&: DIEValueAllocator, Attribute: static_cast<dwarf::Attribute>(0),
883 Form: dwarf::DW_FORM_ref_addr, Value: DIEEntry(*ArtificialDIEPtr));
884
885 addSInt(Die&: *Loc, Form: dwarf::DW_FORM_sdata, Integer: 0);
886
887 addBlock(Die&: VariableDie, Attribute: dwarf::DW_AT_location, Loc);
888 return true;
889}
890
891void DwarfCompileUnit::applyConcreteDbgVariableAttributes(
892 const Loc::Single &Single, const DbgVariable &DV, DIE &VariableDie) {
893 // Handle DW_OP_LLVM_implicit_pointer before normal location emission.
894 if (emitImplicitPointerLocation(Single, DV, VariableDie))
895 return;
896
897 const DbgValueLoc *DVal = &Single.getValueLoc();
898 if (!Single.getExpr())
899 DD->addTargetVariableAttributes(CU&: *this, Die&: VariableDie, TargetAddrSpace: std::nullopt,
900 VarLocKind: DwarfDebug::VariableLocationKind::Register);
901 if (!DVal->isVariadic()) {
902 const DbgValueLocEntry *Entry = DVal->getLocEntries().begin();
903 if (Entry->isLocation()) {
904 addVariableAddress(DV, Die&: VariableDie, Location: Entry->getLoc());
905 } else if (Entry->isInt()) {
906 auto *Expr = Single.getExpr();
907 if (Expr && Expr->getNumElements()) {
908 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
909 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
910 // If there is an expression, emit raw unsigned bytes.
911 DwarfExpr.addFragmentOffset(Expr);
912 DwarfExpr.addUnsignedConstant(Value: Entry->getInt());
913 DwarfExpr.addExpression(Expr);
914 addBlock(Die&: VariableDie, Attribute: dwarf::DW_AT_location, Loc: DwarfExpr.finalize());
915 if (DwarfExpr.TagOffset)
916 addUInt(Die&: VariableDie, Attribute: dwarf::DW_AT_LLVM_tag_offset,
917 Form: dwarf::DW_FORM_data1, Integer: *DwarfExpr.TagOffset);
918 } else
919 addConstantValue(Die&: VariableDie, Val: Entry->getInt(), Ty: DV.getType());
920 } else if (Entry->isConstantFP()) {
921 addConstantFPValue(Die&: VariableDie, CFP: Entry->getConstantFP());
922 } else if (Entry->isConstantInt()) {
923 addConstantValue(Die&: VariableDie, CI: Entry->getConstantInt(), Ty: DV.getType());
924 } else if (Entry->isTargetIndexLocation()) {
925 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
926 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
927 const DIBasicType *BT = dyn_cast<DIBasicType>(
928 Val: static_cast<const Metadata *>(DV.getVariable()->getType()));
929 DwarfDebug::emitDebugLocValue(AP: *Asm, BT, Value: *DVal, DwarfExpr);
930 addBlock(Die&: VariableDie, Attribute: dwarf::DW_AT_location, Loc: DwarfExpr.finalize());
931 }
932 return;
933 }
934 // If any of the location entries are registers with the value 0,
935 // then the location is undefined.
936 if (any_of(Range: DVal->getLocEntries(), P: [](const DbgValueLocEntry &Entry) {
937 return Entry.isLocation() && !Entry.getLoc().getReg();
938 }))
939 return;
940 const DIExpression *Expr = Single.getExpr();
941 assert(Expr && "Variadic Debug Value must have an Expression.");
942 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
943 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
944 DwarfExpr.addFragmentOffset(Expr);
945 DIExpressionCursor Cursor(Expr);
946 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
947
948 auto AddEntry = [&](const DbgValueLocEntry &Entry,
949 DIExpressionCursor &Cursor) {
950 if (Entry.isLocation()) {
951 if (!DwarfExpr.addMachineRegExpression(TRI, Expr&: Cursor,
952 MachineReg: Entry.getLoc().getReg()))
953 return false;
954 } else if (Entry.isInt()) {
955 // If there is an expression, emit raw unsigned bytes.
956 DwarfExpr.addUnsignedConstant(Value: Entry.getInt());
957 } else if (Entry.isConstantFP()) {
958 // DwarfExpression does not support arguments wider than 64 bits
959 // (see PR52584).
960 // TODO: Consider chunking expressions containing overly wide
961 // arguments into separate pointer-sized fragment expressions.
962 APInt RawBytes = Entry.getConstantFP()->getValueAPF().bitcastToAPInt();
963 if (RawBytes.getBitWidth() > 64)
964 return false;
965 DwarfExpr.addUnsignedConstant(Value: RawBytes.getZExtValue());
966 } else if (Entry.isConstantInt()) {
967 APInt RawBytes = Entry.getConstantInt()->getValue();
968 if (RawBytes.getBitWidth() > 64)
969 return false;
970 DwarfExpr.addUnsignedConstant(Value: RawBytes.getZExtValue());
971 } else if (Entry.isTargetIndexLocation()) {
972 TargetIndexLocation Loc = Entry.getTargetIndexLocation();
973 // TODO TargetIndexLocation is a target-independent. Currently
974 // only the WebAssembly-specific encoding is supported.
975 assert(Asm->TM.getTargetTriple().isWasm());
976 DwarfExpr.addWasmLocation(Index: Loc.Index, Offset: static_cast<uint64_t>(Loc.Offset));
977 } else {
978 llvm_unreachable("Unsupported Entry type.");
979 }
980 return true;
981 };
982
983 if (!DwarfExpr.addExpression(
984 Expr: std::move(Cursor),
985 InsertArg: [&](unsigned Idx, DIExpressionCursor &Cursor) -> bool {
986 return AddEntry(DVal->getLocEntries()[Idx], Cursor);
987 }))
988 return;
989
990 // Now attach the location information to the DIE.
991 addBlock(Die&: VariableDie, Attribute: dwarf::DW_AT_location, Loc: DwarfExpr.finalize());
992 if (DwarfExpr.TagOffset)
993 addUInt(Die&: VariableDie, Attribute: dwarf::DW_AT_LLVM_tag_offset, Form: dwarf::DW_FORM_data1,
994 Integer: *DwarfExpr.TagOffset);
995}
996
997void DwarfCompileUnit::applyConcreteDbgVariableAttributes(
998 const Loc::Multi &Multi, const DbgVariable &DV, DIE &VariableDie) {
999 addLocationList(Die&: VariableDie, Attribute: dwarf::DW_AT_location,
1000 Index: Multi.getDebugLocListIndex());
1001 auto TagOffset = Multi.getDebugLocListTagOffset();
1002 if (TagOffset)
1003 addUInt(Die&: VariableDie, Attribute: dwarf::DW_AT_LLVM_tag_offset, Form: dwarf::DW_FORM_data1,
1004 Integer: *TagOffset);
1005}
1006
1007void DwarfCompileUnit::applyConcreteDbgVariableAttributes(const Loc::MMI &MMI,
1008 const DbgVariable &DV,
1009 DIE &VariableDie) {
1010 std::optional<unsigned> TargetAddrSpace;
1011 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1012 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1013 for (const auto &Fragment : MMI.getFrameIndexExprs()) {
1014 Register FrameReg;
1015 const DIExpression *Expr = Fragment.Expr;
1016 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
1017 StackOffset Offset =
1018 TFI->getFrameIndexReference(MF: *Asm->MF, FI: Fragment.FI, FrameReg);
1019 DwarfExpr.addFragmentOffset(Expr);
1020
1021 auto *TRI = Asm->MF->getSubtarget().getRegisterInfo();
1022 SmallVector<uint64_t, 8> Ops;
1023 TRI->getOffsetOpcodes(Offset, Ops);
1024
1025 Expr = DD->adjustExpressionForTarget(Expr, TargetAddrSpace);
1026 if (Expr)
1027 Ops.append(in_start: Expr->elements_begin(), in_end: Expr->elements_end());
1028 DIExpressionCursor Cursor(Ops);
1029 DwarfExpr.setMemoryLocationKind();
1030 if (const MCSymbol *FrameSymbol = Asm->getFunctionFrameSymbol())
1031 addOpAddress(Die&: *Loc, Sym: FrameSymbol);
1032 else
1033 DwarfExpr.addMachineRegExpression(
1034 TRI: *Asm->MF->getSubtarget().getRegisterInfo(), Expr&: Cursor, MachineReg: FrameReg);
1035 DwarfExpr.addExpression(Expr: std::move(Cursor));
1036 }
1037 DD->addTargetVariableAttributes(CU&: *this, Die&: VariableDie, TargetAddrSpace,
1038 VarLocKind: DwarfDebug::VariableLocationKind::FrameIndex);
1039 addBlock(Die&: VariableDie, Attribute: dwarf::DW_AT_location, Loc: DwarfExpr.finalize());
1040 if (DwarfExpr.TagOffset)
1041 addUInt(Die&: VariableDie, Attribute: dwarf::DW_AT_LLVM_tag_offset, Form: dwarf::DW_FORM_data1,
1042 Integer: *DwarfExpr.TagOffset);
1043}
1044
1045void DwarfCompileUnit::applyConcreteDbgVariableAttributes(
1046 const Loc::EntryValue &EntryValue, const DbgVariable &DV,
1047 DIE &VariableDie) {
1048 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1049 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1050 // Emit each expression as: EntryValue(Register) <other ops> <Fragment>.
1051 for (auto [Register, Expr] : EntryValue.EntryValues) {
1052 DwarfExpr.addFragmentOffset(Expr: &Expr);
1053 DIExpressionCursor Cursor(Expr.getElements());
1054 DwarfExpr.beginEntryValueExpression(ExprCursor&: Cursor);
1055 DwarfExpr.addMachineRegExpression(
1056 TRI: *Asm->MF->getSubtarget().getRegisterInfo(), Expr&: Cursor, MachineReg: Register);
1057 DwarfExpr.addExpression(Expr: std::move(Cursor));
1058 }
1059 addBlock(Die&: VariableDie, Attribute: dwarf::DW_AT_location, Loc: DwarfExpr.finalize());
1060}
1061
1062void DwarfCompileUnit::applyConcreteDbgVariableAttributes(
1063 const std::monostate &, const DbgVariable &DV, DIE &VariableDie) {}
1064
1065DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
1066 const LexicalScope &Scope,
1067 DIE *&ObjectPointer) {
1068 auto Var = constructVariableDIE(DV, Abstract: Scope.isAbstractScope());
1069 if (DV.isObjectPointer())
1070 ObjectPointer = Var;
1071 return Var;
1072}
1073
1074DIE *DwarfCompileUnit::constructLabelDIE(DbgLabel &DL,
1075 const LexicalScope &Scope) {
1076 auto LabelDie = DIE::get(Alloc&: DIEValueAllocator, Tag: DL.getTag());
1077 insertDIE(Desc: DL.getLabel(), D: LabelDie);
1078 DL.setDIE(*LabelDie);
1079
1080 if (Scope.isAbstractScope())
1081 applyLabelAttributes(Label: DL, LabelDie&: *LabelDie);
1082
1083 return LabelDie;
1084}
1085
1086/// Return all DIVariables that appear in count: expressions.
1087static SmallVector<const DIVariable *, 2> dependencies(DbgVariable *Var) {
1088 SmallVector<const DIVariable *, 2> Result;
1089 auto *Array = dyn_cast<DICompositeType>(Val: Var->getType());
1090 if (!Array || Array->getTag() != dwarf::DW_TAG_array_type)
1091 return Result;
1092 if (auto *DLVar = Array->getDataLocation())
1093 Result.push_back(Elt: DLVar);
1094 if (auto *AsVar = Array->getAssociated())
1095 Result.push_back(Elt: AsVar);
1096 if (auto *AlVar = Array->getAllocated())
1097 Result.push_back(Elt: AlVar);
1098 for (auto *El : Array->getElements()) {
1099 if (auto *Subrange = dyn_cast<DISubrange>(Val: El)) {
1100 if (auto Count = Subrange->getCount())
1101 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: Count))
1102 Result.push_back(Elt: Dependency);
1103 if (auto LB = Subrange->getLowerBound())
1104 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: LB))
1105 Result.push_back(Elt: Dependency);
1106 if (auto UB = Subrange->getUpperBound())
1107 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: UB))
1108 Result.push_back(Elt: Dependency);
1109 if (auto ST = Subrange->getStride())
1110 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: ST))
1111 Result.push_back(Elt: Dependency);
1112 } else if (auto *GenericSubrange = dyn_cast<DIGenericSubrange>(Val: El)) {
1113 if (auto Count = GenericSubrange->getCount())
1114 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: Count))
1115 Result.push_back(Elt: Dependency);
1116 if (auto LB = GenericSubrange->getLowerBound())
1117 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: LB))
1118 Result.push_back(Elt: Dependency);
1119 if (auto UB = GenericSubrange->getUpperBound())
1120 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: UB))
1121 Result.push_back(Elt: Dependency);
1122 if (auto ST = GenericSubrange->getStride())
1123 if (auto *Dependency = dyn_cast_if_present<DIVariable *>(Val&: ST))
1124 Result.push_back(Elt: Dependency);
1125 }
1126 }
1127 return Result;
1128}
1129
1130/// Sort local variables so that variables appearing inside of helper
1131/// expressions come first.
1132static SmallVector<DbgVariable *, 8>
1133sortLocalVars(SmallVectorImpl<DbgVariable *> &Input) {
1134 SmallVector<DbgVariable *, 8> Result;
1135 SmallVector<PointerIntPair<DbgVariable *, 1>, 8> WorkList;
1136 // Map back from a DIVariable to its containing DbgVariable.
1137 SmallDenseMap<const DILocalVariable *, DbgVariable *> DbgVar;
1138 // Set of DbgVariables in Result.
1139 SmallDenseSet<DbgVariable *, 8> Visited;
1140 // For cycle detection.
1141 SmallDenseSet<DbgVariable *, 8> Visiting;
1142
1143 // Initialize the worklist and the DIVariable lookup table.
1144 for (auto *Var : reverse(C&: Input)) {
1145 DbgVar.insert(KV: {Var->getVariable(), Var});
1146 WorkList.push_back(Elt: {Var, 0});
1147 }
1148
1149 // Perform a stable topological sort by doing a DFS.
1150 while (!WorkList.empty()) {
1151 auto Item = WorkList.back();
1152 DbgVariable *Var = Item.getPointer();
1153 bool visitedAllDependencies = Item.getInt();
1154 WorkList.pop_back();
1155
1156 assert(Var);
1157
1158 // Already handled.
1159 if (Visited.count(V: Var))
1160 continue;
1161
1162 // Add to Result if all dependencies are visited.
1163 if (visitedAllDependencies) {
1164 Visited.insert(V: Var);
1165 Result.push_back(Elt: Var);
1166 continue;
1167 }
1168
1169 // Detect cycles.
1170 auto Res = Visiting.insert(V: Var);
1171 if (!Res.second) {
1172 assert(false && "dependency cycle in local variables");
1173 return Result;
1174 }
1175
1176 // Push dependencies and this node onto the worklist, so that this node is
1177 // visited again after all of its dependencies are handled.
1178 WorkList.push_back(Elt: {Var, 1});
1179 for (const auto *Dependency : dependencies(Var)) {
1180 // Don't add dependency if it is in a different lexical scope or a global.
1181 if (const auto *Dep = dyn_cast<const DILocalVariable>(Val: Dependency))
1182 if (DbgVariable *Var = DbgVar.lookup(Val: Dep))
1183 WorkList.push_back(Elt: {Var, 0});
1184 }
1185 }
1186 return Result;
1187}
1188
1189DIE &DwarfCompileUnit::constructSubprogramScopeDIE(const DISubprogram *Sub,
1190 const Function &F,
1191 LexicalScope *Scope,
1192 MCSymbol *LineTableSym) {
1193 DIE &ScopeDIE = updateSubprogramScopeDIE(SP: Sub, F, LineTableSym);
1194
1195 if (Scope) {
1196 assert(!Scope->getInlinedAt());
1197 assert(!Scope->isAbstractScope());
1198 // Collect lexical scope children first.
1199 // ObjectPointer might be a local (non-argument) local variable if it's a
1200 // block's synthetic this pointer.
1201 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
1202 addDIEEntry(Die&: ScopeDIE, Attribute: dwarf::DW_AT_object_pointer, Entry&: *ObjectPointer);
1203 }
1204
1205 // If this is a variadic function, add an unspecified parameter.
1206 auto *SPTy = Sub->getType();
1207 if (!SPTy)
1208 return ScopeDIE;
1209
1210 DITypeArray FnArgs = SPTy->getTypeArray();
1211
1212 // If we have a single element of null, it is a function that returns void.
1213 // If we have more than one elements and the last one is null, it is a
1214 // variadic function.
1215 if (FnArgs.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
1216 !includeMinimalInlineScopes())
1217 ScopeDIE.addChild(
1218 Child: DIE::get(Alloc&: DIEValueAllocator, Tag: dwarf::DW_TAG_unspecified_parameters));
1219
1220 return ScopeDIE;
1221}
1222
1223bool DwarfCompileUnit::hasGlobalVariableInScope(const DILocalScope *ScopeNode) {
1224 return GlobalVarScopes.contains(Ptr: ScopeNode);
1225}
1226
1227DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
1228 DIE &ScopeDIE) {
1229 DIE *ObjectPointer = nullptr;
1230
1231 // Emit function arguments (order is significant).
1232 auto Vars = DU->getScopeVariables().lookup(Val: Scope);
1233 for (auto &DV : Vars.Args)
1234 ScopeDIE.addChild(Child: constructVariableDIE(DV&: *DV.second, Scope: *Scope, ObjectPointer));
1235
1236 // Emit local variables.
1237 auto Locals = sortLocalVars(Input&: Vars.Locals);
1238 for (DbgVariable *DV : Locals)
1239 ScopeDIE.addChild(Child: constructVariableDIE(DV&: *DV, Scope: *Scope, ObjectPointer));
1240
1241 // Emit labels.
1242 for (DbgLabel *DL : DU->getScopeLabels().lookup(Val: Scope))
1243 ScopeDIE.addChild(Child: constructLabelDIE(DL&: *DL, Scope: *Scope));
1244
1245 // Track other local entities (skipped in gmlt-like data).
1246 // This creates mapping between CU and a set of local declarations that
1247 // should be emitted for subprograms in this CU.
1248 if (!includeMinimalInlineScopes() && !Scope->getInlinedAt()) {
1249 auto &LocalDecls = DD->getLocalDeclsForScope(S: Scope->getScopeNode());
1250 DeferredLocalDecls.insert_range(R&: LocalDecls);
1251 }
1252
1253 // Emit inner lexical scopes.
1254 auto skipLexicalScope = [this](LexicalScope *S) -> bool {
1255 const DILocalScope *DS = S->getScopeNode();
1256 if (isa<DISubprogram>(Val: DS))
1257 return false;
1258 // Don't skip abstract lexical blocks that are scope targets for global
1259 // variables (e.g., function-scope statics). Those globals are emitted
1260 // later in endModule() and need to find the block via
1261 // getOrCreateContextDIE().
1262 if (S->isAbstractScope() && hasGlobalVariableInScope(ScopeNode: DS))
1263 return false;
1264 // Create a concrete lexical block for a scope with an abstract lexical
1265 // block to ensure visibility of scope-local types and static variables
1266 // within the scope range.
1267 if (getAbstractScopeDIEs().lookup(Val: DS))
1268 return false;
1269 auto Vars = DU->getScopeVariables().lookup(Val: S);
1270 if (!Vars.Args.empty() || !Vars.Locals.empty())
1271 return false;
1272 return includeMinimalInlineScopes() ||
1273 DD->getLocalDeclsForScope(S: DS).empty();
1274 };
1275 for (LexicalScope *LS : Scope->getChildren()) {
1276 // If the lexical block doesn't have non-scope children or global
1277 // variables scoped to it, skip its emission and put its children directly
1278 // to the parent scope.
1279 if (skipLexicalScope(LS))
1280 createAndAddScopeChildren(Scope: LS, ScopeDIE);
1281 else
1282 constructScopeDIE(Scope: LS, ParentScopeDIE&: ScopeDIE);
1283 }
1284
1285 return ObjectPointer;
1286}
1287
1288DIE &DwarfCompileUnit::getOrCreateAbstractSubprogramDIE(
1289 const DISubprogram *SP) {
1290 if (auto *AbsDef = getAbstractScopeDIEs().lookup(Val: SP))
1291 return *AbsDef;
1292
1293 auto [ContextDIE, ContextCU] = getOrCreateAbstractSubprogramContextDIE(SP);
1294 return createAbstractSubprogramDIE(SP, ContextDIE, ContextCU);
1295}
1296
1297DIE &DwarfCompileUnit::createAbstractSubprogramDIE(
1298 const DISubprogram *SP, DIE *ContextDIE, DwarfCompileUnit *ContextCU) {
1299 // Passing null as the associated node because the abstract definition
1300 // shouldn't be found by lookup.
1301 DIE &AbsDef = ContextCU->createAndAddDIE(Tag: dwarf::DW_TAG_subprogram,
1302 Parent&: *ContextDIE, N: nullptr);
1303
1304 // Store the DIE before creating children.
1305 ContextCU->getAbstractScopeDIEs()[SP] = &AbsDef;
1306
1307 ContextCU->applySubprogramAttributesToDefinition(SP, SPDie&: AbsDef);
1308 ContextCU->addSInt(Die&: AbsDef, Attribute: dwarf::DW_AT_inline,
1309 Form: DD->getDwarfVersion() <= 4 ? std::optional<dwarf::Form>()
1310 : dwarf::DW_FORM_implicit_const,
1311 Integer: dwarf::DW_INL_inlined);
1312
1313 return AbsDef;
1314}
1315
1316std::pair<DIE *, DwarfCompileUnit *>
1317DwarfCompileUnit::getOrCreateAbstractSubprogramContextDIE(
1318 const DISubprogram *SP) {
1319 bool Minimal = includeMinimalInlineScopes();
1320 bool IgnoreScope = shouldPlaceInUnitDIE(SP, Minimal);
1321 DIE *ContextDIE = getOrCreateSubprogramContextDIE(SP, IgnoreScope);
1322
1323 if (auto *SPDecl = SP->getDeclaration())
1324 if (!Minimal)
1325 getOrCreateSubprogramDIE(SP: SPDecl, F: nullptr);
1326
1327 // The scope may be shared with a subprogram that has already been
1328 // constructed in another CU, in which case we need to construct this
1329 // subprogram in the same CU.
1330 auto *ContextCU = IgnoreScope ? this : DD->lookupCU(Die: ContextDIE->getUnitDie());
1331
1332 return std::make_pair(x&: ContextDIE, y&: ContextCU);
1333}
1334
1335void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(
1336 LexicalScope *Scope) {
1337 auto *SP = cast<DISubprogram>(Val: Scope->getScopeNode());
1338
1339 // Populate subprogram DIE only once.
1340 if (!getFinalizedAbstractSubprograms().insert(Ptr: SP).second)
1341 return;
1342
1343 auto [ContextDIE, ContextCU] = getOrCreateAbstractSubprogramContextDIE(SP);
1344 DIE *AbsDef = getAbstractScopeDIEs().lookup(Val: SP);
1345 if (!AbsDef)
1346 AbsDef = &createAbstractSubprogramDIE(SP, ContextDIE, ContextCU);
1347
1348 if (DIE *ObjectPointer = ContextCU->createAndAddScopeChildren(Scope, ScopeDIE&: *AbsDef))
1349 ContextCU->addDIEEntry(Die&: *AbsDef, Attribute: dwarf::DW_AT_object_pointer,
1350 Entry&: *ObjectPointer);
1351}
1352
1353bool DwarfCompileUnit::useGNUAnalogForDwarf5Feature() const {
1354 return DD->getDwarfVersion() <= 4 && !DD->tuneForLLDB();
1355}
1356
1357dwarf::Tag DwarfCompileUnit::getDwarf5OrGNUTag(dwarf::Tag Tag) const {
1358 if (!useGNUAnalogForDwarf5Feature())
1359 return Tag;
1360 switch (Tag) {
1361 case dwarf::DW_TAG_call_site:
1362 return dwarf::DW_TAG_GNU_call_site;
1363 case dwarf::DW_TAG_call_site_parameter:
1364 return dwarf::DW_TAG_GNU_call_site_parameter;
1365 default:
1366 llvm_unreachable("DWARF5 tag with no GNU analog");
1367 }
1368}
1369
1370dwarf::Attribute
1371DwarfCompileUnit::getDwarf5OrGNUAttr(dwarf::Attribute Attr) const {
1372 if (!useGNUAnalogForDwarf5Feature())
1373 return Attr;
1374 switch (Attr) {
1375 case dwarf::DW_AT_call_all_calls:
1376 return dwarf::DW_AT_GNU_all_call_sites;
1377 case dwarf::DW_AT_call_target:
1378 return dwarf::DW_AT_GNU_call_site_target;
1379 case dwarf::DW_AT_call_target_clobbered:
1380 return dwarf::DW_AT_GNU_call_site_target_clobbered;
1381 case dwarf::DW_AT_call_origin:
1382 return dwarf::DW_AT_abstract_origin;
1383 case dwarf::DW_AT_call_return_pc:
1384 return dwarf::DW_AT_low_pc;
1385 case dwarf::DW_AT_call_value:
1386 return dwarf::DW_AT_GNU_call_site_value;
1387 case dwarf::DW_AT_call_tail_call:
1388 return dwarf::DW_AT_GNU_tail_call;
1389 default:
1390 llvm_unreachable("DWARF5 attribute with no GNU analog");
1391 }
1392}
1393
1394dwarf::LocationAtom
1395DwarfCompileUnit::getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const {
1396 if (!useGNUAnalogForDwarf5Feature())
1397 return Loc;
1398 switch (Loc) {
1399 case dwarf::DW_OP_entry_value:
1400 return dwarf::DW_OP_GNU_entry_value;
1401 default:
1402 llvm_unreachable("DWARF5 location atom with no GNU analog");
1403 }
1404}
1405
1406DIE &DwarfCompileUnit::constructCallSiteEntryDIE(
1407 DIE &ScopeDIE, const DISubprogram *CalleeSP, const Function *CalleeF,
1408 bool IsTail, const MCSymbol *PCAddr, const MCSymbol *CallAddr,
1409 MachineLocation CallTarget, int64_t Offset, DIType *AllocSiteTy) {
1410 // Insert a call site entry DIE within ScopeDIE.
1411 DIE &CallSiteDIE = createAndAddDIE(Tag: getDwarf5OrGNUTag(Tag: dwarf::DW_TAG_call_site),
1412 Parent&: ScopeDIE, N: nullptr);
1413
1414 // A valid register in CallTarget indicates an indirect call.
1415 if (CallTarget.getReg()) {
1416 // Add a DW_AT_call_target location expression describing the location of
1417 // the address of the target function. If any register in the expression
1418 // (i.e., the single register we currently handle) is volatile we must use
1419 // DW_AT_call_target_clobbered instead.
1420 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1421 dwarf::Attribute Attribute = getDwarf5OrGNUAttr(
1422 Attr: TRI.isCalleeSavedPhysReg(PhysReg: CallTarget.getReg(), MF: *Asm->MF)
1423 ? dwarf::DW_AT_call_target
1424 : dwarf::DW_AT_call_target_clobbered);
1425
1426 // CallTarget is the location of the address of an indirect call. The
1427 // location may be indirect, modified by Offset.
1428 if (CallTarget.isIndirect())
1429 addMemoryLocation(Die&: CallSiteDIE, Attribute, Location: CallTarget, Offset);
1430 else
1431 addAddress(Die&: CallSiteDIE, Attribute, Location: CallTarget);
1432 } else if (CalleeSP) {
1433 DIE *CalleeDIE = getOrCreateSubprogramDIE(SP: CalleeSP, F: CalleeF);
1434 assert(CalleeDIE && "Could not create DIE for call site entry origin");
1435 addLinkageNamesToDeclarations(DD: *DD, CalleeSP: *CalleeSP, CalleeDIE&: *CalleeDIE);
1436
1437 addDIEEntry(Die&: CallSiteDIE, Attribute: getDwarf5OrGNUAttr(Attr: dwarf::DW_AT_call_origin),
1438 Entry&: *CalleeDIE);
1439 }
1440
1441 if (IsTail) {
1442 // Attach DW_AT_call_tail_call to tail calls for standards compliance.
1443 addFlag(Die&: CallSiteDIE, Attribute: getDwarf5OrGNUAttr(Attr: dwarf::DW_AT_call_tail_call));
1444
1445 // Attach the address of the branch instruction to allow the debugger to
1446 // show where the tail call occurred. This attribute has no GNU analog.
1447 //
1448 // GDB works backwards from non-standard usage of DW_AT_low_pc (in DWARF4
1449 // mode -- equivalently, in DWARF5 mode, DW_AT_call_return_pc) at tail-call
1450 // site entries to figure out the PC of tail-calling branch instructions.
1451 // This means it doesn't need the compiler to emit DW_AT_call_pc, so we
1452 // don't emit it here.
1453 //
1454 // There's no need to tie non-GDB debuggers to this non-standardness, as it
1455 // adds unnecessary complexity to the debugger. For non-GDB debuggers, emit
1456 // the standard DW_AT_call_pc info.
1457 if (!useGNUAnalogForDwarf5Feature())
1458 addLabelAddress(Die&: CallSiteDIE, Attribute: dwarf::DW_AT_call_pc, Label: CallAddr);
1459 }
1460
1461 // Attach the return PC to allow the debugger to disambiguate call paths
1462 // from one function to another.
1463 //
1464 // The return PC is only really needed when the call /isn't/ a tail call, but
1465 // GDB expects it in DWARF4 mode, even for tail calls (see the comment above
1466 // the DW_AT_call_pc emission logic for an explanation).
1467 if (!IsTail || useGNUAnalogForDwarf5Feature()) {
1468 assert(PCAddr && "Missing return PC information for a call");
1469 addLabelAddress(Die&: CallSiteDIE,
1470 Attribute: getDwarf5OrGNUAttr(Attr: dwarf::DW_AT_call_return_pc), Label: PCAddr);
1471 }
1472
1473 if (AllocSiteTy)
1474 addType(Entity&: CallSiteDIE, Ty: AllocSiteTy, Attribute: dwarf::DW_AT_LLVM_alloc_type);
1475
1476 return CallSiteDIE;
1477}
1478
1479void DwarfCompileUnit::constructCallSiteParmEntryDIEs(
1480 DIE &CallSiteDIE, SmallVector<DbgCallSiteParam, 4> &Params) {
1481 for (const auto &Param : Params) {
1482 unsigned Register = Param.getRegister();
1483 auto CallSiteDieParam =
1484 DIE::get(Alloc&: DIEValueAllocator,
1485 Tag: getDwarf5OrGNUTag(Tag: dwarf::DW_TAG_call_site_parameter));
1486 insertDIE(D: CallSiteDieParam);
1487 addAddress(Die&: *CallSiteDieParam, Attribute: dwarf::DW_AT_location,
1488 Location: MachineLocation(Register));
1489
1490 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1491 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1492 DwarfExpr.setCallSiteParamValueFlag();
1493
1494 DwarfDebug::emitDebugLocValue(AP: *Asm, BT: nullptr, Value: Param.getValue(), DwarfExpr);
1495
1496 addBlock(Die&: *CallSiteDieParam, Attribute: getDwarf5OrGNUAttr(Attr: dwarf::DW_AT_call_value),
1497 Loc: DwarfExpr.finalize());
1498
1499 CallSiteDIE.addChild(Child: CallSiteDieParam);
1500 }
1501}
1502
1503DIE *DwarfCompileUnit::constructImportedEntityDIE(
1504 const DIImportedEntity *Module) {
1505 DIE *IMDie = DIE::get(Alloc&: DIEValueAllocator, Tag: Module->getTag());
1506 insertDIE(Desc: Module, D: IMDie);
1507 DIE *EntityDie;
1508 auto *Entity = Module->getEntity();
1509 if (auto *NS = dyn_cast<DINamespace>(Val: Entity))
1510 EntityDie = getOrCreateNameSpace(NS);
1511 else if (auto *M = dyn_cast<DIModule>(Val: Entity))
1512 EntityDie = getOrCreateModule(M);
1513 else if (auto *SP = dyn_cast<DISubprogram>(Val: Entity)) {
1514 // If there is an abstract subprogram, refer to it. Note that this assumes
1515 // that all the abstract subprograms have been already created (which is
1516 // correct until imported entities get emitted in DwarfDebug::endModule()).
1517 if (auto *AbsSPDie = getAbstractScopeDIEs().lookup(Val: SP))
1518 EntityDie = AbsSPDie;
1519 else
1520 EntityDie = getOrCreateSubprogramDIE(SP, F: nullptr);
1521 } else if (auto *T = dyn_cast<DIType>(Val: Entity))
1522 EntityDie = getOrCreateTypeDIE(TyNode: T);
1523 else if (auto *GV = dyn_cast<DIGlobalVariable>(Val: Entity))
1524 EntityDie = getOrCreateGlobalVariableDIE(GV, GlobalExprs: {});
1525 else if (auto *IE = dyn_cast<DIImportedEntity>(Val: Entity))
1526 EntityDie = getOrCreateImportedEntityDIE(IE);
1527 else
1528 EntityDie = getDIE(D: Entity);
1529 assert(EntityDie);
1530 addSourceLine(Die&: *IMDie, Line: Module->getLine(), /*Column*/ 0, File: Module->getFile());
1531 addDIEEntry(Die&: *IMDie, Attribute: dwarf::DW_AT_import, Entry&: *EntityDie);
1532 StringRef Name = Module->getName();
1533 if (!Name.empty()) {
1534 addString(Die&: *IMDie, Attribute: dwarf::DW_AT_name, Str: Name);
1535
1536 // FIXME: if consumers ever start caring about handling
1537 // unnamed import declarations such as `using ::nullptr_t`
1538 // or `using namespace std::ranges`, we could add the
1539 // import declaration into the accelerator table with the
1540 // name being the one of the entity being imported.
1541 DD->addAccelNamespace(Unit: *this, NameTableKind: CUNode->getNameTableKind(), Name, Die: *IMDie);
1542 }
1543
1544 // This is for imported module with renamed entities (such as variables and
1545 // subprograms).
1546 DINodeArray Elements = Module->getElements();
1547 for (const auto *Element : Elements) {
1548 if (!Element)
1549 continue;
1550 IMDie->addChild(
1551 Child: constructImportedEntityDIE(Module: cast<DIImportedEntity>(Val: Element)));
1552 }
1553
1554 return IMDie;
1555}
1556
1557DIE *DwarfCompileUnit::getOrCreateImportedEntityDIE(
1558 const DIImportedEntity *IE) {
1559
1560 // Check for pre-existence.
1561 if (DIE *Die = getDIE(D: IE))
1562 return Die;
1563
1564 DIE *ContextDIE = getOrCreateContextDIE(Ty: IE->getScope());
1565 assert(ContextDIE && "Empty scope for the imported entity!");
1566
1567 DIE *IMDie = constructImportedEntityDIE(Module: IE);
1568 ContextDIE->addChild(Child: IMDie);
1569 return IMDie;
1570}
1571
1572void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
1573 DIE *D = getDIE(D: SP);
1574 if (DIE *AbsSPDIE = getAbstractScopeDIEs().lookup(Val: SP)) {
1575 if (D)
1576 // If this subprogram has an abstract definition, reference that
1577 addDIEEntry(Die&: *D, Attribute: dwarf::DW_AT_abstract_origin, Entry&: *AbsSPDIE);
1578 } else {
1579 assert(D || includeMinimalInlineScopes());
1580 if (D)
1581 // And attach the attributes
1582 applySubprogramAttributesToDefinition(SP, SPDie&: *D);
1583 }
1584}
1585
1586void DwarfCompileUnit::finishEntityDefinition(const DbgEntity *Entity) {
1587 DbgEntity *AbsEntity = getExistingAbstractEntity(Node: Entity->getEntity());
1588
1589 auto *Die = Entity->getDIE();
1590 /// Label may be used to generate DW_AT_low_pc, so put it outside
1591 /// if/else block.
1592 const DbgLabel *Label = nullptr;
1593 if (AbsEntity && AbsEntity->getDIE()) {
1594 addDIEEntry(Die&: *Die, Attribute: dwarf::DW_AT_abstract_origin, Entry&: *AbsEntity->getDIE());
1595 Label = dyn_cast<const DbgLabel>(Val: Entity);
1596 } else {
1597 if (const DbgVariable *Var = dyn_cast<const DbgVariable>(Val: Entity))
1598 applyCommonDbgVariableAttributes(Var: *Var, VariableDie&: *Die);
1599 else if ((Label = dyn_cast<const DbgLabel>(Val: Entity)))
1600 applyLabelAttributes(Label: *Label, LabelDie&: *Die);
1601 else
1602 llvm_unreachable("DbgEntity must be DbgVariable or DbgLabel.");
1603 }
1604
1605 if (!Label)
1606 return;
1607
1608 const auto *Sym = Label->getSymbol();
1609 if (!Sym)
1610 return;
1611
1612 addLabelAddress(Die&: *Die, Attribute: dwarf::DW_AT_low_pc, Label: Sym);
1613
1614 // A TAG_label with a name and an AT_low_pc must be placed in debug_names.
1615 if (StringRef Name = Label->getName(); !Name.empty())
1616 getDwarfDebug().addAccelName(Unit: *this, NameTableKind: CUNode->getNameTableKind(), Name, Die: *Die);
1617}
1618
1619void DwarfCompileUnit::attachLexicalScopesAbstractOrigins() {
1620 auto AttachAO = [&](const DILocalScope *LS, DIE *ScopeDIE) {
1621 if (auto *AbsLSDie = getAbstractScopeDIEs().lookup(Val: LS))
1622 addDIEEntry(Die&: *ScopeDIE, Attribute: dwarf::DW_AT_abstract_origin, Entry&: *AbsLSDie);
1623 };
1624
1625 for (auto [LScope, ScopeDIE] : LexicalBlockDIEs)
1626 AttachAO(LScope, ScopeDIE);
1627 for (auto &[LScope, ScopeDIEs] : InlinedLocalScopeDIEs)
1628 for (auto *ScopeDIE : ScopeDIEs)
1629 AttachAO(LScope, ScopeDIE);
1630}
1631
1632DbgEntity *DwarfCompileUnit::getExistingAbstractEntity(const DINode *Node) {
1633 auto &AbstractEntities = getAbstractEntities();
1634 auto I = AbstractEntities.find(Val: Node);
1635 if (I != AbstractEntities.end())
1636 return I->second.get();
1637 return nullptr;
1638}
1639
1640void DwarfCompileUnit::createAbstractEntity(const DINode *Node,
1641 LexicalScope *Scope) {
1642 assert(Scope && Scope->isAbstractScope());
1643 auto &Entity = getAbstractEntities()[Node];
1644 if (isa<const DILocalVariable>(Val: Node)) {
1645 Entity = std::make_unique<DbgVariable>(args: cast<const DILocalVariable>(Val: Node),
1646 args: nullptr /* IA */);
1647 DU->addScopeVariable(LS: Scope, Var: cast<DbgVariable>(Val: Entity.get()));
1648 } else if (isa<const DILabel>(Val: Node)) {
1649 Entity = std::make_unique<DbgLabel>(
1650 args: cast<const DILabel>(Val: Node), args: nullptr /* IA */);
1651 DU->addScopeLabel(LS: Scope, Label: cast<DbgLabel>(Val: Entity.get()));
1652 }
1653}
1654
1655void DwarfCompileUnit::emitHeader(bool UseOffsets) {
1656 // Don't bother labeling the .dwo unit, as its offset isn't used.
1657 if (!Skeleton && !DD->useSectionsAsReferences()) {
1658 LabelBegin = Asm->createTempSymbol(Name: "cu_begin");
1659 Asm->OutStreamer->emitLabel(Symbol: LabelBegin);
1660 }
1661
1662 dwarf::UnitType UT = Skeleton ? dwarf::DW_UT_split_compile
1663 : DD->useSplitDwarf() ? dwarf::DW_UT_skeleton
1664 : dwarf::DW_UT_compile;
1665 DwarfUnit::emitCommonHeader(UseOffsets, UT);
1666 if (DD->getDwarfVersion() >= 5 && UT != dwarf::DW_UT_compile)
1667 Asm->emitInt64(Value: getDWOId());
1668}
1669
1670bool DwarfCompileUnit::hasDwarfPubSections() const {
1671 if (!DD->shouldEmitDwarfPubSections())
1672 return false;
1673
1674 switch (CUNode->getNameTableKind()) {
1675 case DICompileUnit::DebugNameTableKind::None:
1676 return false;
1677 // Opting in to GNU Pubnames/types overrides the default to ensure these are
1678 // generated for things like Gold's gdb_index generation.
1679 case DICompileUnit::DebugNameTableKind::GNU:
1680 return true;
1681 case DICompileUnit::DebugNameTableKind::Apple:
1682 return false;
1683 case DICompileUnit::DebugNameTableKind::Default:
1684 return DD->tuneForGDB() && !includeMinimalInlineScopes() &&
1685 !CUNode->isDebugDirectivesOnly() &&
1686 DD->getAccelTableKind() != AccelTableKind::Apple &&
1687 DD->getDwarfVersion() < 5;
1688 }
1689 llvm_unreachable("Unhandled DICompileUnit::DebugNameTableKind enum");
1690}
1691
1692/// addGlobalName - Add a new global name to the compile unit.
1693void DwarfCompileUnit::addGlobalName(StringRef Name, const DIE &Die,
1694 const DIScope *Context) {
1695 if (!hasDwarfPubSections())
1696 return;
1697 std::string FullName = getParentContextString(Context) + Name.str();
1698 GlobalNames[FullName] = &Die;
1699}
1700
1701void DwarfCompileUnit::addGlobalNameForTypeUnit(StringRef Name,
1702 const DIScope *Context) {
1703 if (!hasDwarfPubSections())
1704 return;
1705 std::string FullName = getParentContextString(Context) + Name.str();
1706 // Insert, allowing the entry to remain as-is if it's already present
1707 // This way the CU-level type DIE is preferred over the "can't describe this
1708 // type as a unit offset because it's not really in the CU at all, it's only
1709 // in a type unit"
1710 GlobalNames.insert(KV: std::make_pair(x: std::move(FullName), y: &getUnitDie()));
1711}
1712
1713/// Add a new global type to the unit.
1714void DwarfCompileUnit::addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
1715 const DIScope *Context) {
1716 if (!hasDwarfPubSections())
1717 return;
1718 std::string FullName = getParentContextString(Context) + Ty->getName().str();
1719 GlobalTypes[FullName] = &Die;
1720}
1721
1722void DwarfCompileUnit::addGlobalTypeUnitType(const DIType *Ty,
1723 const DIScope *Context) {
1724 if (!hasDwarfPubSections())
1725 return;
1726 std::string FullName = getParentContextString(Context) + Ty->getName().str();
1727 // Insert, allowing the entry to remain as-is if it's already present
1728 // This way the CU-level type DIE is preferred over the "can't describe this
1729 // type as a unit offset because it's not really in the CU at all, it's only
1730 // in a type unit"
1731 GlobalTypes.insert(KV: std::make_pair(x: std::move(FullName), y: &getUnitDie()));
1732}
1733
1734void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
1735 MachineLocation Location) {
1736 auto *Single = std::get_if<Loc::Single>(ptr: &DV);
1737 if (Single && Single->getExpr())
1738 addComplexAddress(DIExpr: Single->getExpr(), Die, Attribute: dwarf::DW_AT_location, Location);
1739 else
1740 addAddress(Die, Attribute: dwarf::DW_AT_location, Location);
1741}
1742
1743void DwarfCompileUnit::addLocationWithExpr(DIE &Die, dwarf::Attribute Attribute,
1744 const MachineLocation &Location,
1745 ArrayRef<uint64_t> Expr) {
1746 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1747 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1748 if (Location.isIndirect())
1749 DwarfExpr.setMemoryLocationKind();
1750
1751 DIExpressionCursor Cursor(Expr);
1752 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1753 if (!DwarfExpr.addMachineRegExpression(TRI, Expr&: Cursor, MachineReg: Location.getReg()))
1754 return;
1755 DwarfExpr.addExpression(Expr: std::move(Cursor));
1756
1757 // Now attach the location information to the DIE.
1758 addBlock(Die, Attribute, Loc: DwarfExpr.finalize());
1759
1760 if (DwarfExpr.TagOffset)
1761 addUInt(Die, Attribute: dwarf::DW_AT_LLVM_tag_offset, Form: dwarf::DW_FORM_data1,
1762 Integer: *DwarfExpr.TagOffset);
1763}
1764
1765/// Add an address attribute to a die based on the location provided.
1766void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
1767 const MachineLocation &Location) {
1768 addLocationWithExpr(Die, Attribute, Location, Expr: {});
1769}
1770
1771/// Add a memory location exprloc to \p DIE with attribute \p Attribute
1772/// at \p Location + \p Offset.
1773void DwarfCompileUnit::addMemoryLocation(DIE &Die, dwarf::Attribute Attribute,
1774 const MachineLocation &Location,
1775 int64_t Offset) {
1776 assert(Location.isIndirect() && "Memory loc should be indirect");
1777 SmallVector<uint64_t, 3> Ops;
1778 DIExpression::appendOffset(Ops, Offset);
1779 addLocationWithExpr(Die, Attribute, Location, Expr: Ops);
1780}
1781
1782/// Start with the address based on the location provided, and generate the
1783/// DWARF information necessary to find the actual variable given the extra
1784/// address information encoded in the DbgVariable, starting from the starting
1785/// location. Add the DWARF information to the die.
1786void DwarfCompileUnit::addComplexAddress(const DIExpression *DIExpr, DIE &Die,
1787 dwarf::Attribute Attribute,
1788 const MachineLocation &Location) {
1789 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1790 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1791 DwarfExpr.addFragmentOffset(Expr: DIExpr);
1792 DwarfExpr.setLocation(Loc: Location, DIExpr);
1793
1794 DIExpressionCursor Cursor(DIExpr);
1795
1796 if (DIExpr->isEntryValue())
1797 DwarfExpr.beginEntryValueExpression(ExprCursor&: Cursor);
1798
1799 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1800 if (!DwarfExpr.addMachineRegExpression(TRI, Expr&: Cursor, MachineReg: Location.getReg()))
1801 return;
1802 DwarfExpr.addExpression(Expr: std::move(Cursor));
1803
1804 // Now attach the location information to the DIE.
1805 addBlock(Die, Attribute, Loc: DwarfExpr.finalize());
1806
1807 if (DwarfExpr.TagOffset)
1808 addUInt(Die, Attribute: dwarf::DW_AT_LLVM_tag_offset, Form: dwarf::DW_FORM_data1,
1809 Integer: *DwarfExpr.TagOffset);
1810}
1811
1812/// Add a Dwarf loclistptr attribute data and value.
1813void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
1814 unsigned Index) {
1815 dwarf::Form Form = (DD->getDwarfVersion() >= 5)
1816 ? dwarf::DW_FORM_loclistx
1817 : DD->getDwarfSectionOffsetForm();
1818 addAttribute(Die, Attribute, Form, Value: DIELocList(Index));
1819}
1820
1821void DwarfCompileUnit::applyCommonDbgVariableAttributes(const DbgVariable &Var,
1822 DIE &VariableDie) {
1823 StringRef Name = Var.getName();
1824 if (!Name.empty())
1825 addString(Die&: VariableDie, Attribute: dwarf::DW_AT_name, Str: Name);
1826 const auto *DIVar = Var.getVariable();
1827 if (DIVar) {
1828 if (uint32_t AlignInBytes = DIVar->getAlignInBytes())
1829 addUInt(Die&: VariableDie, Attribute: dwarf::DW_AT_alignment, Form: dwarf::DW_FORM_udata,
1830 Integer: AlignInBytes);
1831 addAnnotation(Buffer&: VariableDie, Annotations: DIVar->getAnnotations());
1832 }
1833
1834 addSourceLine(Die&: VariableDie, V: DIVar);
1835 addType(Entity&: VariableDie, Ty: Var.getType());
1836 if (Var.isArtificial())
1837 addFlag(Die&: VariableDie, Attribute: dwarf::DW_AT_artificial);
1838}
1839
1840void DwarfCompileUnit::applyLabelAttributes(const DbgLabel &Label,
1841 DIE &LabelDie) {
1842 StringRef Name = Label.getName();
1843 if (!Name.empty())
1844 addString(Die&: LabelDie, Attribute: dwarf::DW_AT_name, Str: Name);
1845 const auto *DILabel = Label.getLabel();
1846 addSourceLine(Die&: LabelDie, L: DILabel);
1847 if (DILabel->isArtificial())
1848 addFlag(Die&: LabelDie, Attribute: dwarf::DW_AT_artificial);
1849 if (DILabel->getCoroSuspendIdx())
1850 addUInt(Die&: LabelDie, Attribute: dwarf::DW_AT_LLVM_coro_suspend_idx, Form: std::nullopt,
1851 Integer: *DILabel->getCoroSuspendIdx());
1852}
1853
1854/// Add a Dwarf expression attribute data and value.
1855void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
1856 const MCExpr *Expr) {
1857 addAttribute(Die, Attribute: (dwarf::Attribute)0, Form, Value: DIEExpr(Expr));
1858}
1859
1860void DwarfCompileUnit::applySubprogramAttributesToDefinition(
1861 const DISubprogram *SP, DIE &SPDie) {
1862 auto *SPDecl = SP->getDeclaration();
1863 auto *Context = SPDecl ? SPDecl->getScope() : SP->getScope();
1864 applySubprogramAttributes(SP, SPDie, SkipSPAttributes: includeMinimalInlineScopes());
1865 addGlobalName(Name: SP->getName(), Die: SPDie, Context);
1866}
1867
1868bool DwarfCompileUnit::isDwoUnit() const {
1869 return DD->useSplitDwarf() && Skeleton;
1870}
1871
1872void DwarfCompileUnit::finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) {
1873 constructTypeDIE(Buffer&: D, CTy);
1874}
1875
1876bool DwarfCompileUnit::includeMinimalInlineScopes() const {
1877 return getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly ||
1878 (DD->useSplitDwarf() && !Skeleton);
1879}
1880
1881bool DwarfCompileUnit::emitFuncLineTableOffsets() const {
1882 return EmitFuncLineTableOffsetsOption;
1883}
1884
1885void DwarfCompileUnit::addAddrTableBase() {
1886 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1887 MCSymbol *Label = DD->getAddressPool().getLabel();
1888 addSectionLabel(Die&: getUnitDie(),
1889 Attribute: DD->getDwarfVersion() >= 5 ? dwarf::DW_AT_addr_base
1890 : dwarf::DW_AT_GNU_addr_base,
1891 Label, Sec: TLOF.getDwarfAddrSection()->getBeginSymbol());
1892}
1893
1894void DwarfCompileUnit::addBaseTypeRef(DIEValueList &Die, int64_t Idx) {
1895 addAttribute(Die, Attribute: (dwarf::Attribute)0, Form: dwarf::DW_FORM_udata,
1896 Value: new (DIEValueAllocator) DIEBaseTypeRef(this, Idx));
1897}
1898
1899void DwarfCompileUnit::createBaseTypeDIEs() {
1900 // Insert the base_type DIEs directly after the CU so that their offsets will
1901 // fit in the fixed size ULEB128 used inside the location expressions.
1902 // Maintain order by iterating backwards and inserting to the front of CU
1903 // child list.
1904 for (auto &Btr : reverse(C&: ExprRefedBaseTypes)) {
1905 DIE &Die = getUnitDie().addChildFront(
1906 Child: DIE::get(Alloc&: DIEValueAllocator, Tag: dwarf::DW_TAG_base_type));
1907 SmallString<32> Str;
1908 addString(Die, Attribute: dwarf::DW_AT_name,
1909 Str: Twine(dwarf::AttributeEncodingString(Encoding: Btr.Encoding) +
1910 "_" + Twine(Btr.BitSize)).toStringRef(Out&: Str));
1911 addUInt(Die, Attribute: dwarf::DW_AT_encoding, Form: dwarf::DW_FORM_data1, Integer: Btr.Encoding);
1912 // Round up to smallest number of bytes that contains this number of bits.
1913 // ExprRefedBaseTypes is populated with types referenced by
1914 // DW_OP_LLVM_convert operations in location expressions. These are often
1915 // byte-sized, but one common counter-example is 1-bit sized conversions
1916 // from `i1` types. TODO: Should these use DW_AT_bit_size? See
1917 // DwarfUnit::constructTypeDIE.
1918 addUInt(Die, Attribute: dwarf::DW_AT_byte_size, Form: std::nullopt,
1919 Integer: divideCeil(Numerator: Btr.BitSize, Denominator: 8));
1920 Btr.Die = &Die;
1921 }
1922}
1923
1924DIE *DwarfCompileUnit::getLocalContextDIE(const DILexicalBlock *LB) {
1925 // Assume if there is an abstract tree all the DIEs are already emitted.
1926 bool isAbstract = getAbstractScopeDIEs().count(Val: LB->getSubprogram());
1927 if (isAbstract) {
1928 auto &DIEs = getAbstractScopeDIEs();
1929 if (auto It = DIEs.find(Val: LB); It != DIEs.end())
1930 return It->second;
1931 }
1932 assert(!isAbstract && "Missed lexical block DIE in abstract tree!");
1933
1934 // Check if we have a concrete DIE.
1935 if (auto It = LexicalBlockDIEs.find(Val: LB); It != LexicalBlockDIEs.end())
1936 return It->second;
1937
1938 // If nothing available found, we cannot just create a new lexical block,
1939 // because it isn't known where to put it into the DIE tree.
1940 // So, we may only try to find the most close avaiable parent DIE.
1941 return getOrCreateContextDIE(Ty: LB->getScope()->getNonLexicalBlockFileScope());
1942}
1943
1944DIE *DwarfCompileUnit::getOrCreateContextDIE(const DIScope *Context) {
1945 if (isa_and_nonnull<DILocalScope>(Val: Context)) {
1946 if (auto *LFScope = dyn_cast<DILexicalBlockFile>(Val: Context))
1947 Context = LFScope->getNonLexicalBlockFileScope();
1948 if (auto *LScope = dyn_cast<DILexicalBlock>(Val: Context))
1949 return getLocalContextDIE(LB: LScope);
1950
1951 // Otherwise the context must be a DISubprogram.
1952 auto *SPScope = cast<DISubprogram>(Val: Context);
1953 const auto &DIEs = getAbstractScopeDIEs();
1954 if (auto It = DIEs.find(Val: SPScope); It != DIEs.end())
1955 return It->second;
1956 }
1957 return DwarfUnit::getOrCreateContextDIE(Context);
1958}
1959
1960DIE *DwarfCompileUnit::getOrCreateSubprogramDIE(const DISubprogram *SP,
1961 const Function *F,
1962 bool Minimal) {
1963 if (!F && SP->isDefinition()) {
1964 F = DD->getLexicalScopes().getFunction(SP);
1965
1966 if (!F) {
1967 // SP may belong to another CU. Determine the CU similarly
1968 // to DwarfDebug::constructAbstractSubprogramScopeDIE.
1969 return &DD->getOrCreateAbstractSubprogramCU(SP, SrcCU&: *this)
1970 .getOrCreateAbstractSubprogramDIE(SP);
1971 }
1972 }
1973
1974 return DwarfUnit::getOrCreateSubprogramDIE(SP, FnHint: F, Minimal);
1975}
1976
1977void DwarfCompileUnit::addLinkageNamesToDeclarations(
1978 const DwarfDebug &DD, const DISubprogram &CalleeSP, DIE &CalleeDIE) {
1979 if (AddLinkageNamesToDeclCallOriginsForTuning(DD: &DD) &&
1980 !CalleeSP.isDefinition() &&
1981 !CalleeDIE.findAttribute(Attribute: dwarf::DW_AT_linkage_name)) {
1982 addLinkageName(Die&: CalleeDIE, LinkageName: CalleeSP.getLinkageName());
1983 }
1984}
1985