diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp | 411 |
1 files changed, 0 insertions, 411 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp deleted file mode 100644 index 1e2f55b..0000000 --- a/contrib/llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp +++ /dev/null @@ -1,411 +0,0 @@ -//===-- llvm/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp --*- C++ -*--===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file contains support for writing line tables info into COFF files. -// -//===----------------------------------------------------------------------===// - -#include "WinCodeViewLineTables.h" -#include "llvm/MC/MCExpr.h" -#include "llvm/MC/MCSymbol.h" -#include "llvm/Support/COFF.h" - -namespace llvm { - -StringRef WinCodeViewLineTables::getFullFilepath(const MDNode *S) { - assert(S); - assert((isa<DICompileUnit>(S) || isa<DIFile>(S) || isa<DISubprogram>(S) || - isa<DILexicalBlockBase>(S)) && - "Unexpected scope info"); - - auto *Scope = cast<DIScope>(S); - StringRef Dir = Scope->getDirectory(), - Filename = Scope->getFilename(); - std::string &Filepath = - DirAndFilenameToFilepathMap[std::make_pair(Dir, Filename)]; - if (!Filepath.empty()) - return Filepath; - - // Clang emits directory and relative filename info into the IR, but CodeView - // operates on full paths. We could change Clang to emit full paths too, but - // that would increase the IR size and probably not needed for other users. - // For now, just concatenate and canonicalize the path here. - if (Filename.find(':') == 1) - Filepath = Filename; - else - Filepath = (Dir + "\\" + Filename).str(); - - // Canonicalize the path. We have to do it textually because we may no longer - // have access the file in the filesystem. - // First, replace all slashes with backslashes. - std::replace(Filepath.begin(), Filepath.end(), '/', '\\'); - - // Remove all "\.\" with "\". - size_t Cursor = 0; - while ((Cursor = Filepath.find("\\.\\", Cursor)) != std::string::npos) - Filepath.erase(Cursor, 2); - - // Replace all "\XXX\..\" with "\". Don't try too hard though as the original - // path should be well-formatted, e.g. start with a drive letter, etc. - Cursor = 0; - while ((Cursor = Filepath.find("\\..\\", Cursor)) != std::string::npos) { - // Something's wrong if the path starts with "\..\", abort. - if (Cursor == 0) - break; - - size_t PrevSlash = Filepath.rfind('\\', Cursor - 1); - if (PrevSlash == std::string::npos) - // Something's wrong, abort. - break; - - Filepath.erase(PrevSlash, Cursor + 3 - PrevSlash); - // The next ".." might be following the one we've just erased. - Cursor = PrevSlash; - } - - // Remove all duplicate backslashes. - Cursor = 0; - while ((Cursor = Filepath.find("\\\\", Cursor)) != std::string::npos) - Filepath.erase(Cursor, 1); - - return Filepath; -} - -void WinCodeViewLineTables::maybeRecordLocation(DebugLoc DL, - const MachineFunction *MF) { - const MDNode *Scope = DL.getScope(); - if (!Scope) - return; - unsigned LineNumber = DL.getLine(); - // Skip this line if it is longer than the maximum we can record. - if (LineNumber > COFF::CVL_MaxLineNumber) - return; - - unsigned ColumnNumber = DL.getCol(); - // Truncate the column number if it is longer than the maximum we can record. - if (ColumnNumber > COFF::CVL_MaxColumnNumber) - ColumnNumber = 0; - - StringRef Filename = getFullFilepath(Scope); - - // Skip this instruction if it has the same file:line as the previous one. - assert(CurFn); - if (!CurFn->Instrs.empty()) { - const InstrInfoTy &LastInstr = InstrInfo[CurFn->Instrs.back()]; - if (LastInstr.Filename == Filename && LastInstr.LineNumber == LineNumber && - LastInstr.ColumnNumber == ColumnNumber) - return; - } - FileNameRegistry.add(Filename); - - MCSymbol *MCL = Asm->MMI->getContext().createTempSymbol(); - Asm->OutStreamer->EmitLabel(MCL); - CurFn->Instrs.push_back(MCL); - InstrInfo[MCL] = InstrInfoTy(Filename, LineNumber, ColumnNumber); -} - -WinCodeViewLineTables::WinCodeViewLineTables(AsmPrinter *AP) - : Asm(nullptr), CurFn(nullptr) { - MachineModuleInfo *MMI = AP->MMI; - - // If module doesn't have named metadata anchors or COFF debug section - // is not available, skip any debug info related stuff. - if (!MMI->getModule()->getNamedMetadata("llvm.dbg.cu") || - !AP->getObjFileLowering().getCOFFDebugSymbolsSection()) - return; - - // Tell MMI that we have debug info. - MMI->setDebugInfoAvailability(true); - Asm = AP; -} - -void WinCodeViewLineTables::endModule() { - if (FnDebugInfo.empty()) - return; - - assert(Asm != nullptr); - Asm->OutStreamer->SwitchSection( - Asm->getObjFileLowering().getCOFFDebugSymbolsSection()); - Asm->EmitInt32(COFF::DEBUG_SECTION_MAGIC); - - // The COFF .debug$S section consists of several subsections, each starting - // with a 4-byte control code (e.g. 0xF1, 0xF2, etc) and then a 4-byte length - // of the payload followed by the payload itself. The subsections are 4-byte - // aligned. - - // Emit per-function debug information. This code is extracted into a - // separate function for readability. - for (size_t I = 0, E = VisitedFunctions.size(); I != E; ++I) - emitDebugInfoForFunction(VisitedFunctions[I]); - - // This subsection holds a file index to offset in string table table. - Asm->OutStreamer->AddComment("File index to string table offset subsection"); - Asm->EmitInt32(COFF::DEBUG_INDEX_SUBSECTION); - size_t NumFilenames = FileNameRegistry.Infos.size(); - Asm->EmitInt32(8 * NumFilenames); - for (size_t I = 0, E = FileNameRegistry.Filenames.size(); I != E; ++I) { - StringRef Filename = FileNameRegistry.Filenames[I]; - // For each unique filename, just write its offset in the string table. - Asm->EmitInt32(FileNameRegistry.Infos[Filename].StartOffset); - // The function name offset is not followed by any additional data. - Asm->EmitInt32(0); - } - - // This subsection holds the string table. - Asm->OutStreamer->AddComment("String table"); - Asm->EmitInt32(COFF::DEBUG_STRING_TABLE_SUBSECTION); - Asm->EmitInt32(FileNameRegistry.LastOffset); - // The payload starts with a null character. - Asm->EmitInt8(0); - - for (size_t I = 0, E = FileNameRegistry.Filenames.size(); I != E; ++I) { - // Just emit unique filenames one by one, separated by a null character. - Asm->OutStreamer->EmitBytes(FileNameRegistry.Filenames[I]); - Asm->EmitInt8(0); - } - - // No more subsections. Fill with zeros to align the end of the section by 4. - Asm->OutStreamer->EmitFill((-FileNameRegistry.LastOffset) % 4, 0); - - clear(); -} - -static void EmitLabelDiff(MCStreamer &Streamer, - const MCSymbol *From, const MCSymbol *To, - unsigned int Size = 4) { - MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None; - MCContext &Context = Streamer.getContext(); - const MCExpr *FromRef = MCSymbolRefExpr::create(From, Variant, Context), - *ToRef = MCSymbolRefExpr::create(To, Variant, Context); - const MCExpr *AddrDelta = - MCBinaryExpr::create(MCBinaryExpr::Sub, ToRef, FromRef, Context); - Streamer.EmitValue(AddrDelta, Size); -} - -void WinCodeViewLineTables::emitDebugInfoForFunction(const Function *GV) { - // For each function there is a separate subsection - // which holds the PC to file:line table. - const MCSymbol *Fn = Asm->getSymbol(GV); - assert(Fn); - - const FunctionInfo &FI = FnDebugInfo[GV]; - if (FI.Instrs.empty()) - return; - assert(FI.End && "Don't know where the function ends?"); - - StringRef GVName = GV->getName(); - StringRef FuncName; - if (auto *SP = getDISubprogram(GV)) - FuncName = SP->getDisplayName(); - - // FIXME Clang currently sets DisplayName to "bar" for a C++ - // "namespace_foo::bar" function, see PR21528. Luckily, dbghelp.dll is trying - // to demangle display names anyways, so let's just put a mangled name into - // the symbols subsection until Clang gives us what we need. - if (GVName.startswith("\01?")) - FuncName = GVName.substr(1); - // Emit a symbol subsection, required by VS2012+ to find function boundaries. - MCSymbol *SymbolsBegin = Asm->MMI->getContext().createTempSymbol(), - *SymbolsEnd = Asm->MMI->getContext().createTempSymbol(); - Asm->OutStreamer->AddComment("Symbol subsection for " + Twine(FuncName)); - Asm->EmitInt32(COFF::DEBUG_SYMBOL_SUBSECTION); - EmitLabelDiff(*Asm->OutStreamer, SymbolsBegin, SymbolsEnd); - Asm->OutStreamer->EmitLabel(SymbolsBegin); - { - MCSymbol *ProcSegmentBegin = Asm->MMI->getContext().createTempSymbol(), - *ProcSegmentEnd = Asm->MMI->getContext().createTempSymbol(); - EmitLabelDiff(*Asm->OutStreamer, ProcSegmentBegin, ProcSegmentEnd, 2); - Asm->OutStreamer->EmitLabel(ProcSegmentBegin); - - Asm->EmitInt16(COFF::DEBUG_SYMBOL_TYPE_PROC_START); - // Some bytes of this segment don't seem to be required for basic debugging, - // so just fill them with zeroes. - Asm->OutStreamer->EmitFill(12, 0); - // This is the important bit that tells the debugger where the function - // code is located and what's its size: - EmitLabelDiff(*Asm->OutStreamer, Fn, FI.End); - Asm->OutStreamer->EmitFill(12, 0); - Asm->OutStreamer->EmitCOFFSecRel32(Fn); - Asm->OutStreamer->EmitCOFFSectionIndex(Fn); - Asm->EmitInt8(0); - // Emit the function display name as a null-terminated string. - Asm->OutStreamer->EmitBytes(FuncName); - Asm->EmitInt8(0); - Asm->OutStreamer->EmitLabel(ProcSegmentEnd); - - // We're done with this function. - Asm->EmitInt16(0x0002); - Asm->EmitInt16(COFF::DEBUG_SYMBOL_TYPE_PROC_END); - } - Asm->OutStreamer->EmitLabel(SymbolsEnd); - // Every subsection must be aligned to a 4-byte boundary. - Asm->OutStreamer->EmitFill((-FuncName.size()) % 4, 0); - - // PCs/Instructions are grouped into segments sharing the same filename. - // Pre-calculate the lengths (in instructions) of these segments and store - // them in a map for convenience. Each index in the map is the sequential - // number of the respective instruction that starts a new segment. - DenseMap<size_t, size_t> FilenameSegmentLengths; - size_t LastSegmentEnd = 0; - StringRef PrevFilename = InstrInfo[FI.Instrs[0]].Filename; - for (size_t J = 1, F = FI.Instrs.size(); J != F; ++J) { - if (PrevFilename == InstrInfo[FI.Instrs[J]].Filename) - continue; - FilenameSegmentLengths[LastSegmentEnd] = J - LastSegmentEnd; - LastSegmentEnd = J; - PrevFilename = InstrInfo[FI.Instrs[J]].Filename; - } - FilenameSegmentLengths[LastSegmentEnd] = FI.Instrs.size() - LastSegmentEnd; - - // Emit a line table subsection, required to do PC-to-file:line lookup. - Asm->OutStreamer->AddComment("Line table subsection for " + Twine(FuncName)); - Asm->EmitInt32(COFF::DEBUG_LINE_TABLE_SUBSECTION); - MCSymbol *LineTableBegin = Asm->MMI->getContext().createTempSymbol(), - *LineTableEnd = Asm->MMI->getContext().createTempSymbol(); - EmitLabelDiff(*Asm->OutStreamer, LineTableBegin, LineTableEnd); - Asm->OutStreamer->EmitLabel(LineTableBegin); - - // Identify the function this subsection is for. - Asm->OutStreamer->EmitCOFFSecRel32(Fn); - Asm->OutStreamer->EmitCOFFSectionIndex(Fn); - // Insert flags after a 16-bit section index. - Asm->EmitInt16(COFF::DEBUG_LINE_TABLES_HAVE_COLUMN_RECORDS); - - // Length of the function's code, in bytes. - EmitLabelDiff(*Asm->OutStreamer, Fn, FI.End); - - // PC-to-linenumber lookup table: - MCSymbol *FileSegmentEnd = nullptr; - - // The start of the last segment: - size_t LastSegmentStart = 0; - - auto FinishPreviousChunk = [&] { - if (!FileSegmentEnd) - return; - for (size_t ColSegI = LastSegmentStart, - ColSegEnd = ColSegI + FilenameSegmentLengths[LastSegmentStart]; - ColSegI != ColSegEnd; ++ColSegI) { - unsigned ColumnNumber = InstrInfo[FI.Instrs[ColSegI]].ColumnNumber; - assert(ColumnNumber <= COFF::CVL_MaxColumnNumber); - Asm->EmitInt16(ColumnNumber); // Start column - Asm->EmitInt16(0); // End column - } - Asm->OutStreamer->EmitLabel(FileSegmentEnd); - }; - - for (size_t J = 0, F = FI.Instrs.size(); J != F; ++J) { - MCSymbol *Instr = FI.Instrs[J]; - assert(InstrInfo.count(Instr)); - - if (FilenameSegmentLengths.count(J)) { - // We came to a beginning of a new filename segment. - FinishPreviousChunk(); - StringRef CurFilename = InstrInfo[FI.Instrs[J]].Filename; - assert(FileNameRegistry.Infos.count(CurFilename)); - size_t IndexInStringTable = - FileNameRegistry.Infos[CurFilename].FilenameID; - // Each segment starts with the offset of the filename - // in the string table. - Asm->OutStreamer->AddComment( - "Segment for file '" + Twine(CurFilename) + "' begins"); - MCSymbol *FileSegmentBegin = Asm->MMI->getContext().createTempSymbol(); - Asm->OutStreamer->EmitLabel(FileSegmentBegin); - Asm->EmitInt32(8 * IndexInStringTable); - - // Number of PC records in the lookup table. - size_t SegmentLength = FilenameSegmentLengths[J]; - Asm->EmitInt32(SegmentLength); - - // Full size of the segment for this filename, including the prev two - // records. - FileSegmentEnd = Asm->MMI->getContext().createTempSymbol(); - EmitLabelDiff(*Asm->OutStreamer, FileSegmentBegin, FileSegmentEnd); - LastSegmentStart = J; - } - - // The first PC with the given linenumber and the linenumber itself. - EmitLabelDiff(*Asm->OutStreamer, Fn, Instr); - uint32_t LineNumber = InstrInfo[Instr].LineNumber; - assert(LineNumber <= COFF::CVL_MaxLineNumber); - uint32_t LineData = LineNumber | COFF::CVL_IsStatement; - Asm->EmitInt32(LineData); - } - - FinishPreviousChunk(); - Asm->OutStreamer->EmitLabel(LineTableEnd); -} - -void WinCodeViewLineTables::beginFunction(const MachineFunction *MF) { - assert(!CurFn && "Can't process two functions at once!"); - - if (!Asm || !Asm->MMI->hasDebugInfo()) - return; - - const Function *GV = MF->getFunction(); - assert(FnDebugInfo.count(GV) == false); - VisitedFunctions.push_back(GV); - CurFn = &FnDebugInfo[GV]; - - // Find the end of the function prolog. - // FIXME: is there a simpler a way to do this? Can we just search - // for the first instruction of the function, not the last of the prolog? - DebugLoc PrologEndLoc; - bool EmptyPrologue = true; - for (const auto &MBB : *MF) { - if (PrologEndLoc) - break; - for (const auto &MI : MBB) { - if (MI.isDebugValue()) - continue; - - // First known non-DBG_VALUE and non-frame setup location marks - // the beginning of the function body. - // FIXME: do we need the first subcondition? - if (!MI.getFlag(MachineInstr::FrameSetup) && MI.getDebugLoc()) { - PrologEndLoc = MI.getDebugLoc(); - break; - } - EmptyPrologue = false; - } - } - // Record beginning of function if we have a non-empty prologue. - if (PrologEndLoc && !EmptyPrologue) { - DebugLoc FnStartDL = PrologEndLoc.getFnDebugLoc(); - maybeRecordLocation(FnStartDL, MF); - } -} - -void WinCodeViewLineTables::endFunction(const MachineFunction *MF) { - if (!Asm || !CurFn) // We haven't created any debug info for this function. - return; - - const Function *GV = MF->getFunction(); - assert(FnDebugInfo.count(GV)); - assert(CurFn == &FnDebugInfo[GV]); - - if (CurFn->Instrs.empty()) { - FnDebugInfo.erase(GV); - VisitedFunctions.pop_back(); - } else { - CurFn->End = Asm->getFunctionEnd(); - } - CurFn = nullptr; -} - -void WinCodeViewLineTables::beginInstruction(const MachineInstr *MI) { - // Ignore DBG_VALUE locations and function prologue. - if (!Asm || MI->isDebugValue() || MI->getFlag(MachineInstr::FrameSetup)) - return; - DebugLoc DL = MI->getDebugLoc(); - if (DL == PrevInstLoc || !DL) - return; - maybeRecordLocation(DL, Asm->MF); -} -} |
