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