Update to LLVM 3.5a.
Change-Id: Ifadecab779f128e62e430c2b4f6ddd84953ed617
diff --git a/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp b/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp
new file mode 100644
index 0000000..50b2ca8
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/WinCodeViewLineTables.cpp
@@ -0,0 +1,336 @@
+//===-- 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);
+ DIDescriptor D(S);
+ assert((D.isCompileUnit() || D.isFile() || D.isSubprogram() ||
+ D.isLexicalBlockFile() || D.isLexicalBlock()) &&
+ "Unexpected scope info");
+
+ DIScope Scope(S);
+ StringRef Dir = Scope.getDirectory(),
+ Filename = Scope.getFilename();
+ char *&Result = DirAndFilenameToFilepathMap[std::make_pair(Dir, Filename)];
+ if (Result != 0)
+ return Result;
+
+ // 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.
+ std::string Filepath;
+ if (Filename.find(':') == 1)
+ Filepath = Filename;
+ else
+ Filepath = (Dir + Twine("\\") + 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);
+
+ Result = strdup(Filepath.c_str());
+ return StringRef(Result);
+}
+
+void WinCodeViewLineTables::maybeRecordLocation(DebugLoc DL,
+ const MachineFunction *MF) {
+ const MDNode *Scope = DL.getScope(MF->getFunction()->getContext());
+ if (!Scope)
+ return;
+ 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 == DL.getLine())
+ return;
+ }
+ FileNameRegistry.add(Filename);
+
+ MCSymbol *MCL = Asm->MMI->getContext().CreateTempSymbol();
+ Asm->OutStreamer.EmitLabel(MCL);
+ CurFn->Instrs.push_back(MCL);
+ InstrInfo[MCL] = InstrInfoTy(Filename, DL.getLine());
+}
+
+WinCodeViewLineTables::WinCodeViewLineTables(AsmPrinter *AP)
+ : Asm(0), CurFn(0) {
+ 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;
+}
+
+static void EmitLabelDiff(MCStreamer &Streamer,
+ const MCSymbol *From, const MCSymbol *To) {
+ 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, 4);
+}
+
+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?");
+
+ // 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 the control code of the subsection followed by the payload size.
+ Asm->OutStreamer.AddComment(
+ "Linetable subsection for " + Twine(Fn->getName()));
+ Asm->EmitInt32(COFF::DEBUG_LINE_TABLE_SUBSECTION);
+ MCSymbol *SubsectionBegin = Asm->MMI->getContext().CreateTempSymbol(),
+ *SubsectionEnd = Asm->MMI->getContext().CreateTempSymbol();
+ EmitLabelDiff(Asm->OutStreamer, SubsectionBegin, SubsectionEnd);
+ Asm->OutStreamer.EmitLabel(SubsectionBegin);
+
+ // Identify the function this subsection is for.
+ Asm->OutStreamer.EmitCOFFSecRel32(Fn);
+ Asm->OutStreamer.EmitCOFFSectionIndex(Fn);
+
+ // Length of the function's code, in bytes.
+ EmitLabelDiff(Asm->OutStreamer, Fn, FI.End);
+
+ // PC-to-linenumber lookup table:
+ MCSymbol *FileSegmentEnd = 0;
+ 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.
+ if (FileSegmentEnd)
+ Asm->OutStreamer.EmitLabel(FileSegmentEnd);
+ 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);
+ }
+
+ // The first PC with the given linenumber and the linenumber itself.
+ EmitLabelDiff(Asm->OutStreamer, Fn, Instr);
+ Asm->EmitInt32(InstrInfo[Instr].LineNumber);
+ }
+
+ if (FileSegmentEnd)
+ Asm->OutStreamer.EmitLabel(FileSegmentEnd);
+ Asm->OutStreamer.EmitLabel(SubsectionEnd);
+}
+
+void WinCodeViewLineTables::endModule() {
+ if (FnDebugInfo.empty())
+ return;
+
+ assert(Asm != 0);
+ 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.
+
+ 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 it's 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();
+}
+
+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 (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
+ I != E && PrologEndLoc.isUnknown(); ++I) {
+ for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
+ II != IE; ++II) {
+ const MachineInstr *MI = II;
+ 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().isUnknown())) {
+ PrologEndLoc = MI->getDebugLoc();
+ break;
+ }
+ EmptyPrologue = false;
+ }
+ }
+ // Record beginning of function if we have a non-empty prologue.
+ if (!PrologEndLoc.isUnknown() && !EmptyPrologue) {
+ DebugLoc FnStartDL =
+ PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
+ 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) == true);
+ assert(CurFn == &FnDebugInfo[GV]);
+
+ if (CurFn->Instrs.empty()) {
+ FnDebugInfo.erase(GV);
+ VisitedFunctions.pop_back();
+ } else {
+ // Define end label for subprogram.
+ MCSymbol *FunctionEndSym = Asm->OutStreamer.getContext().CreateTempSymbol();
+ Asm->OutStreamer.EmitLabel(FunctionEndSym);
+ CurFn->End = FunctionEndSym;
+ }
+ CurFn = 0;
+}
+
+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.isUnknown())
+ return;
+ maybeRecordLocation(DL, Asm->MF);
+}
+}