}
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?");
+ const StringRef FuncName = getDISubprogram(GV).getDisplayName();
+ // 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 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 a line table subsection, requred to do PC-to-file:line lookup.
- Asm->OutStreamer.AddComment(
- "Line table subsection for " + Twine(Fn->getName()));
+ 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);
if (FileSegmentEnd)
Asm->OutStreamer.EmitLabel(FileSegmentEnd);
- Asm->OutStreamer.EmitLabel(SubsectionEnd);
+ Asm->OutStreamer.EmitLabel(LineTableEnd);
}
void WinCodeViewLineTables::beginFunction(const MachineFunction *MF) {