| //===-- llvm/CodeGen/DwarfFile.cpp - Dwarf Debug Framework ----------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "DwarfFile.h" |
| #include "DwarfDebug.h" |
| #include "DwarfUnit.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/Support/LEB128.h" |
| #include "llvm/Target/TargetLoweringObjectFile.h" |
| |
| namespace llvm { |
| DwarfFile::DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA) |
| : Asm(AP), StrPool(DA, *Asm, Pref) {} |
| |
| DwarfFile::~DwarfFile() {} |
| |
| // Define a unique number for the abbreviation. |
| // |
| void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) { |
| // Check the set for priors. |
| DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev); |
| |
| // If it's newly added. |
| if (InSet == &Abbrev) { |
| // Add to abbreviation list. |
| Abbreviations.push_back(&Abbrev); |
| |
| // Assign the vector position + 1 as its number. |
| Abbrev.setNumber(Abbreviations.size()); |
| } else { |
| // Assign existing abbreviation number. |
| Abbrev.setNumber(InSet->getNumber()); |
| } |
| } |
| |
| void DwarfFile::addUnit(std::unique_ptr<DwarfUnit> U) { |
| CUs.push_back(std::move(U)); |
| } |
| |
| // Emit the various dwarf units to the unit section USection with |
| // the abbreviations going into ASection. |
| void DwarfFile::emitUnits(bool UseOffsets) { |
| for (const auto &TheU : CUs) { |
| DIE &Die = TheU->getUnitDie(); |
| const MCSection *USection = TheU->getSection(); |
| Asm->OutStreamer.SwitchSection(USection); |
| |
| TheU->emitHeader(UseOffsets); |
| |
| Asm->emitDwarfDIE(Die); |
| } |
| } |
| |
| // Compute the size and offset for each DIE. |
| void DwarfFile::computeSizeAndOffsets() { |
| // Offset from the first CU in the debug info section is 0 initially. |
| unsigned SecOffset = 0; |
| |
| // Iterate over each compile unit and set the size and offsets for each |
| // DIE within each compile unit. All offsets are CU relative. |
| for (const auto &TheU : CUs) { |
| TheU->setDebugInfoOffset(SecOffset); |
| |
| // CU-relative offset is reset to 0 here. |
| unsigned Offset = sizeof(int32_t) + // Length of Unit Info |
| TheU->getHeaderSize(); // Unit-specific headers |
| |
| // EndOffset here is CU-relative, after laying out |
| // all of the CU DIE. |
| unsigned EndOffset = computeSizeAndOffset(TheU->getUnitDie(), Offset); |
| SecOffset += EndOffset; |
| } |
| } |
| // Compute the size and offset of a DIE. The offset is relative to start of the |
| // CU. It returns the offset after laying out the DIE. |
| unsigned DwarfFile::computeSizeAndOffset(DIE &Die, unsigned Offset) { |
| // Record the abbreviation. |
| assignAbbrevNumber(Die.getAbbrev()); |
| |
| // Get the abbreviation for this DIE. |
| const DIEAbbrev &Abbrev = Die.getAbbrev(); |
| |
| // Set DIE offset |
| Die.setOffset(Offset); |
| |
| // Start the size with the size of abbreviation code. |
| Offset += getULEB128Size(Die.getAbbrevNumber()); |
| |
| const SmallVectorImpl<DIEValue *> &Values = Die.getValues(); |
| const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData(); |
| |
| // Size the DIE attribute values. |
| for (unsigned i = 0, N = Values.size(); i < N; ++i) |
| // Size attribute value. |
| Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm()); |
| |
| // Get the children. |
| const auto &Children = Die.getChildren(); |
| |
| // Size the DIE children if any. |
| if (!Children.empty()) { |
| assert(Abbrev.hasChildren() && "Children flag not set"); |
| |
| for (auto &Child : Children) |
| Offset = computeSizeAndOffset(*Child, Offset); |
| |
| // End of children marker. |
| Offset += sizeof(int8_t); |
| } |
| |
| Die.setSize(Offset - Die.getOffset()); |
| return Offset; |
| } |
| |
| void DwarfFile::emitAbbrevs(const MCSection *Section) { |
| // Check to see if it is worth the effort. |
| if (!Abbreviations.empty()) { |
| // Start the debug abbrev section. |
| Asm->OutStreamer.SwitchSection(Section); |
| Asm->emitDwarfAbbrevs(Abbreviations); |
| } |
| } |
| |
| // Emit strings into a string section. |
| void DwarfFile::emitStrings(const MCSection *StrSection, |
| const MCSection *OffsetSection) { |
| StrPool.emit(*Asm, StrSection, OffsetSection); |
| } |
| |
| bool DwarfFile::addScopeVariable(LexicalScope *LS, DbgVariable *Var) { |
| SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS]; |
| DIVariable DV = Var->getVariable(); |
| // Variables with positive arg numbers are parameters. |
| if (unsigned ArgNum = DV->getArg()) { |
| // Keep all parameters in order at the start of the variable list to ensure |
| // function types are correct (no out-of-order parameters) |
| // |
| // This could be improved by only doing it for optimized builds (unoptimized |
| // builds have the right order to begin with), searching from the back (this |
| // would catch the unoptimized case quickly), or doing a binary search |
| // rather than linear search. |
| auto I = Vars.begin(); |
| while (I != Vars.end()) { |
| unsigned CurNum = (*I)->getVariable()->getArg(); |
| // A local (non-parameter) variable has been found, insert immediately |
| // before it. |
| if (CurNum == 0) |
| break; |
| // A later indexed parameter has been found, insert immediately before it. |
| if (CurNum > ArgNum) |
| break; |
| if (CurNum == ArgNum) { |
| (*I)->addMMIEntry(*Var); |
| return false; |
| } |
| ++I; |
| } |
| Vars.insert(I, Var); |
| return true; |
| } |
| |
| Vars.push_back(Var); |
| return true; |
| } |
| } |