LLVM 19.0.0git
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1//===- llvm/CodeGen/DwarfFile.cpp - Dwarf Debug Framework -----------------===//
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
9#include "DwarfFile.h"
10#include "DwarfCompileUnit.h"
11#include "DwarfDebug.h"
12#include "DwarfUnit.h"
15#include "llvm/MC/MCStreamer.h"
16#include <cstdint>
18using namespace llvm;
21 : Asm(AP), Abbrevs(AbbrevAllocator), StrPool(DA, *Asm, Pref) {}
23void DwarfFile::addUnit(std::unique_ptr<DwarfCompileUnit> U) {
24 CUs.push_back(std::move(U));
27// Emit the various dwarf units to the unit section USection with
28// the abbreviations going into ASection.
29void DwarfFile::emitUnits(bool UseOffsets) {
30 for (const auto &TheU : CUs)
31 emitUnit(TheU.get(), UseOffsets);
34void DwarfFile::emitUnit(DwarfUnit *TheU, bool UseOffsets) {
35 if (TheU->getCUNode()->isDebugDirectivesOnly())
36 return;
38 MCSection *S = TheU->getSection();
40 if (!S)
41 return;
43 // Skip CUs that ended up not being needed (split CUs that were abandoned
44 // because they added no information beyond the non-split CU)
45 if (TheU->getUnitDie().values().empty())
46 return;
48 Asm->OutStreamer->switchSection(S);
49 TheU->emitHeader(UseOffsets);
50 Asm->emitDwarfDIE(TheU->getUnitDie());
52 if (MCSymbol *EndLabel = TheU->getEndLabel())
53 Asm->OutStreamer->emitLabel(EndLabel);
56// Compute the size and offset for each DIE.
58 // Offset from the first CU in the debug info section is 0 initially.
59 uint64_t SecOffset = 0;
61 // Iterate over each compile unit and set the size and offsets for each
62 // DIE within each compile unit. All offsets are CU relative.
63 for (const auto &TheU : CUs) {
64 if (TheU->getCUNode()->isDebugDirectivesOnly())
65 continue;
67 // Skip CUs that ended up not being needed (split CUs that were abandoned
68 // because they added no information beyond the non-split CU)
69 if (TheU->getUnitDie().values().empty())
70 return;
72 TheU->setDebugSectionOffset(SecOffset);
73 SecOffset += computeSizeAndOffsetsForUnit(TheU.get());
74 }
75 if (SecOffset > UINT32_MAX && !Asm->isDwarf64())
76 report_fatal_error("The generated debug information is too large "
77 "for the 32-bit DWARF format.");
81 // CU-relative offset is reset to 0 here.
82 unsigned Offset = Asm->getUnitLengthFieldByteSize() + // Length of Unit Info
83 TheU->getHeaderSize(); // Unit-specific headers
85 // The return value here is CU-relative, after laying out
86 // all of the CU DIE.
87 return computeSizeAndOffset(TheU->getUnitDie(), Offset);
90// Compute the size and offset of a DIE. The offset is relative to start of the
91// CU. It returns the offset after laying out the DIE.
92unsigned DwarfFile::computeSizeAndOffset(DIE &Die, unsigned Offset) {
93 return Die.computeOffsetsAndAbbrevs(Asm->getDwarfFormParams(), Abbrevs,
94 Offset);
97void DwarfFile::emitAbbrevs(MCSection *Section) { Abbrevs.Emit(Asm, Section); }
99// Emit strings into a string section.
100void DwarfFile::emitStrings(MCSection *StrSection, MCSection *OffsetSection,
101 bool UseRelativeOffsets) {
102 StrPool.emit(*Asm, StrSection, OffsetSection, UseRelativeOffsets);
106 auto &ScopeVars = ScopeVariables[LS];
107 const DILocalVariable *DV = Var->getVariable();
108 if (unsigned ArgNum = DV->getArg()) {
109 auto Ret = ScopeVars.Args.insert({ArgNum, Var});
110 assert(Ret.second);
111 (void)Ret;
112 } else {
113 ScopeVars.Locals.push_back(Var);
114 }
118 SmallVectorImpl<DbgLabel *> &Labels = ScopeLabels[LS];
119 Labels.push_back(Label);
122std::pair<uint32_t, RangeSpanList *>
124 CURangeLists.push_back(
125 RangeSpanList{Asm->createTempSymbol("debug_ranges"), &CU, std::move(R)});
126 return std::make_pair(CURangeLists.size() - 1, &CURangeLists.back());
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:84
bool isDwarf64() const
void emitDwarfDIE(const DIE &Die) const
Recursively emit Dwarf DIE tree.
unsigned int getUnitLengthFieldByteSize() const
Returns 4 for DWARF32 and 12 for DWARF64.
MCSymbol * createTempSymbol(const Twine &Name) const
std::unique_ptr< MCStreamer > OutStreamer
This is the MCStreamer object for the file we are generating.
Definition: AsmPrinter.h:99
dwarf::FormParams getDwarfFormParams() const
Returns information about the byte size of DW_FORM values.
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:66
bool isDebugDirectivesOnly() const
void Emit(const AsmPrinter *AP, MCSection *Section) const
Print all abbreviations using the specified asm printer.
Definition: DIE.cpp:164
MCSection * getSection() const
Return the section that this DIEUnit will be emitted into.
Definition: DIE.h:996
DIE & getUnitDie()
Definition: DIE.h:999
value_range values()
Definition: DIE.h:807
A structured debug information entry.
Definition: DIE.h:819
unsigned computeOffsetsAndAbbrevs(const dwarf::FormParams &FormParams, DIEAbbrevSet &AbbrevSet, unsigned CUOffset)
Compute the offset of this DIE and all its children.
Definition: DIE.cpp:270
This class is used to track label information.
Definition: DwarfDebug.h:289
This class is used to track local variable information.
Definition: DwarfDebug.h:214
const DILocalVariable * getVariable() const
Definition: DwarfDebug.h:246
unsigned computeSizeAndOffset(DIE &Die, unsigned Offset)
Compute the size and offset of a DIE given an incoming Offset.
Definition: DwarfFile.cpp:92
void addScopeLabel(LexicalScope *LS, DbgLabel *Label)
Definition: DwarfFile.cpp:117
void addUnit(std::unique_ptr< DwarfCompileUnit > U)
Add a unit to the list of CUs.
Definition: DwarfFile.cpp:23
void computeSizeAndOffsets()
Compute the size and offset of all the DIEs.
Definition: DwarfFile.cpp:57
unsigned computeSizeAndOffsetsForUnit(DwarfUnit *TheU)
Compute the size and offset of all the DIEs in the given unit.
Definition: DwarfFile.cpp:80
void emitUnits(bool UseOffsets)
Emit all of the units to the section listed with the given abbreviation section.
Definition: DwarfFile.cpp:29
void emitUnit(DwarfUnit *TheU, bool UseOffsets)
Emit the given unit to its section.
Definition: DwarfFile.cpp:34
void emitAbbrevs(MCSection *)
Emit a set of abbreviations to the specific section.
Definition: DwarfFile.cpp:97
DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA)
Definition: DwarfFile.cpp:20
void emitStrings(MCSection *StrSection, MCSection *OffsetSection=nullptr, bool UseRelativeOffsets=false)
Emit all of the strings to the section given.
Definition: DwarfFile.cpp:100
void addScopeVariable(LexicalScope *LS, DbgVariable *Var)
Definition: DwarfFile.cpp:105
std::pair< uint32_t, RangeSpanList * > addRange(const DwarfCompileUnit &CU, SmallVector< RangeSpan, 2 > R)
Definition: DwarfFile.cpp:123
void emit(AsmPrinter &Asm, MCSection *StrSection, MCSection *OffsetSection=nullptr, bool UseRelativeOffsets=false)
This dwarf writer support class manages information associated with a source file.
Definition: DwarfUnit.h:35
virtual void emitHeader(bool UseOffsets)=0
Emit the header for this unit, not including the initial length field.
virtual unsigned getHeaderSize() const
Compute the size of a header for this unit, not including the initial length field.
Definition: DwarfUnit.h:281
MCSymbol * getEndLabel() const
Definition: DwarfUnit.h:109
const DICompileUnit * getCUNode() const
Definition: DwarfUnit.h:111
LexicalScope - This class is used to track scope information.
Definition: LexicalScopes.h:44
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:39
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1209
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:456
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:156