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) {
+ 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, 4);
+ Streamer.EmitValue(AddrDelta, Size);
}
void WinCodeViewLineTables::emitDebugInfoForFunction(const Function *GV) {
return;
assert(FI.End && "Don't know where the function ends?");
+ StringRef FuncName = getDISubprogram(GV).getDisplayName(),
+ GVName = GV->getName();
+ // 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
}
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()));
+ // Emit a line table subsection, requred to do PC-to-file:line lookup.
+ Asm->OutStreamer.AddComment("Line table subsection for " + Twine(FuncName));
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);
+ 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 padding after a 16-bit section index.
+ Asm->EmitInt16(0);
// Length of the function's code, in bytes.
EmitLabelDiff(Asm->OutStreamer, Fn, FI.End);
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();
+ Asm->OutStreamer.EmitLabel(LineTableEnd);
}
void WinCodeViewLineTables::beginFunction(const MachineFunction *MF) {
// 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())
+ for (const auto &MBB : *MF) {
+ if (!PrologEndLoc.isUnknown())
+ 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().isUnknown())) {
- PrologEndLoc = MI->getDebugLoc();
+ if (!MI.getFlag(MachineInstr::FrameSetup) &&
+ (!MI.getDebugLoc().isUnknown())) {
+ PrologEndLoc = MI.getDebugLoc();
break;
}
EmptyPrologue = false;
return;
const Function *GV = MF->getFunction();
- assert(FnDebugInfo.count(GV) == true);
+ assert(FnDebugInfo.count(GV));
assert(CurFn == &FnDebugInfo[GV]);
if (CurFn->Instrs.empty()) {