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-rw-r--r--lib/MC/MCDwarf.cpp210
1 files changed, 198 insertions, 12 deletions
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index d7540ce077..c1de31bf06 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -19,6 +19,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetAsmBackend.h"
+#include "llvm/Target/TargetAsmInfo.h"
using namespace llvm;
// Given a special op, return the address skip amount (in units of
@@ -125,8 +126,7 @@ static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS,
//
static inline void EmitDwarfLineTable(MCStreamer *MCOS,
const MCSection *Section,
- const MCLineSection *LineSection,
- const MCSection *DwarfLineSection) {
+ const MCLineSection *LineSection) {
unsigned FileNum = 1;
unsigned LastLine = 1;
unsigned Column = 0;
@@ -185,13 +185,15 @@ static inline void EmitDwarfLineTable(MCStreamer *MCOS,
// Switch to the section to be able to create a symbol at its end.
MCOS->SwitchSection(Section);
+
+ MCContext &context = MCOS->getContext();
// Create a symbol at the end of the section.
- MCSymbol *SectionEnd = MCOS->getContext().CreateTempSymbol();
+ MCSymbol *SectionEnd = context.CreateTempSymbol();
// Set the value of the symbol, as we are at the end of the section.
MCOS->EmitLabel(SectionEnd);
// Switch back the the dwarf line section.
- MCOS->SwitchSection(DwarfLineSection);
+ MCOS->SwitchSection(context.getTargetAsmInfo().getDwarfLineSection());
MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd);
}
@@ -199,18 +201,18 @@ static inline void EmitDwarfLineTable(MCStreamer *MCOS,
//
// This emits the Dwarf file and the line tables.
//
-void MCDwarfFileTable::Emit(MCStreamer *MCOS,
- const MCSection *DwarfLineSection) {
+void MCDwarfFileTable::Emit(MCStreamer *MCOS) {
+ MCContext &context = MCOS->getContext();
// Switch to the section where the table will be emitted into.
- MCOS->SwitchSection(DwarfLineSection);
+ MCOS->SwitchSection(context.getTargetAsmInfo().getDwarfLineSection());
// Create a symbol at the beginning of this section.
- MCSymbol *LineStartSym = MCOS->getContext().CreateTempSymbol();
+ MCSymbol *LineStartSym = context.CreateTempSymbol();
// Set the value of the symbol, as we are at the start of the section.
MCOS->EmitLabel(LineStartSym);
// Create a symbol for the end of the section (to be set when we get there).
- MCSymbol *LineEndSym = MCOS->getContext().CreateTempSymbol();
+ MCSymbol *LineEndSym = context.CreateTempSymbol();
// The first 4 bytes is the total length of the information for this
// compilation unit (not including these 4 bytes for the length).
@@ -221,7 +223,7 @@ void MCDwarfFileTable::Emit(MCStreamer *MCOS,
MCOS->EmitIntValue(2, 2);
// Create a symbol for the end of the prologue (to be set when we get there).
- MCSymbol *ProEndSym = MCOS->getContext().CreateTempSymbol(); // Lprologue_end
+ MCSymbol *ProEndSym = context.CreateTempSymbol(); // Lprologue_end
// Length of the prologue, is the next 4 bytes. Which is the start of the
// section to the end of the prologue. Not including the 4 bytes for the
@@ -256,7 +258,7 @@ void MCDwarfFileTable::Emit(MCStreamer *MCOS,
// First the directory table.
const std::vector<StringRef> &MCDwarfDirs =
- MCOS->getContext().getMCDwarfDirs();
+ context.getMCDwarfDirs();
for (unsigned i = 0; i < MCDwarfDirs.size(); i++) {
MCOS->EmitBytes(MCDwarfDirs[i], 0); // the DirectoryName
MCOS->EmitBytes(StringRef("\0", 1), 0); // the null term. of the string
@@ -290,7 +292,7 @@ void MCDwarfFileTable::Emit(MCStreamer *MCOS,
++it) {
const MCSection *Sec = *it;
const MCLineSection *Line = MCLineSections.lookup(Sec);
- EmitDwarfLineTable(MCOS, Sec, Line, DwarfLineSection);
+ EmitDwarfLineTable(MCOS, Sec, Line);
// Now delete the MCLineSections that were created in MCLineEntry::Make()
// and used to emit the line table.
@@ -425,3 +427,187 @@ void MCDwarfFile::dump() const {
print(dbgs());
}
+static int getDataAlignmentFactor(MCStreamer &streamer) {
+ MCContext &context = streamer.getContext();
+ const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ int size = asmInfo.getPointerSize();
+ if (asmInfo.getStackGrowthDirection() == TargetFrameInfo::StackGrowsUp)
+ return size;
+ else
+ return -size;
+}
+
+/// EmitFrameMoves - Emit frame instructions to describe the layout of the
+/// frame.
+static void EmitFrameMoves(MCStreamer &streamer,
+ const std::vector<MachineMove> &Moves,
+ MCSymbol *BaseLabel, bool isEH) {
+ MCContext &context = streamer.getContext();
+ const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ int dataAlignmentFactor = getDataAlignmentFactor(streamer);
+
+ for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
+ const MachineMove &Move = Moves[i];
+ MCSymbol *Label = Move.getLabel();
+ // Throw out move if the label is invalid.
+ if (Label && !Label->isDefined()) continue; // Not emitted, in dead code.
+
+ const MachineLocation &Dst = Move.getDestination();
+ const MachineLocation &Src = Move.getSource();
+
+ // Advance row if new location.
+ if (BaseLabel && Label) {
+ MCSymbol *ThisSym = Label;
+ if (ThisSym != BaseLabel) {
+ streamer.EmitIntValue(dwarf::DW_CFA_advance_loc4, 1);
+ const MCExpr *Length = MakeStartMinusEndExpr(streamer, *BaseLabel,
+ *ThisSym, 4);
+ streamer.EmitValue(Length, 4);
+ BaseLabel = ThisSym;
+ }
+ }
+
+ // If advancing cfa.
+ if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
+ assert(!Src.isReg() && "Machine move not supported yet.");
+
+ if (Src.getReg() == MachineLocation::VirtualFP) {
+ streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1);
+ } else {
+ streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1);
+ streamer.EmitULEB128IntValue(asmInfo.getDwarfRegNum(Src.getReg(), isEH),
+ 1);
+ }
+
+ streamer.EmitULEB128IntValue(-Src.getOffset(), 1);
+ continue;
+ }
+
+ if (Src.isReg() && Src.getReg() == MachineLocation::VirtualFP) {
+ assert(Dst.isReg() && "Machine move not supported yet.");
+ streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1);
+ streamer.EmitULEB128IntValue(asmInfo.getDwarfRegNum(Dst.getReg(), isEH));
+ continue;
+ }
+
+ unsigned Reg = asmInfo.getDwarfRegNum(Src.getReg(), isEH);
+ int Offset = Dst.getOffset() / dataAlignmentFactor;
+
+ if (Offset < 0) {
+ streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1);
+ streamer.EmitULEB128IntValue(Reg);
+ streamer.EmitSLEB128IntValue(Offset);
+ } else if (Reg < 64) {
+ streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1);
+ streamer.EmitULEB128IntValue(Offset, 1);
+ } else {
+ streamer.EmitIntValue(dwarf::DW_CFA_offset_extended, 1);
+ streamer.EmitULEB128IntValue(Reg, 1);
+ streamer.EmitULEB128IntValue(Offset, 1);
+ }
+ }
+}
+
+static const MCSymbol &EmitCIE(MCStreamer &streamer) {
+ MCContext &context = streamer.getContext();
+ const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ const MCSection &section = *asmInfo.getEHFrameSection();
+ streamer.SwitchSection(&section);
+ MCSymbol *sectionStart = streamer.getContext().CreateTempSymbol();
+ MCSymbol *sectionEnd = streamer.getContext().CreateTempSymbol();
+
+ // Length
+ const MCExpr *Length = MakeStartMinusEndExpr(streamer, *sectionStart,
+ *sectionEnd, 4);
+ streamer.EmitLabel(sectionStart);
+ streamer.EmitValue(Length, 4);
+
+ // CIE ID
+ streamer.EmitIntValue(0, 4);
+
+ // Version
+ streamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1);
+
+ // Augmentation String
+ SmallString<8> Augmentation;
+ Augmentation += "zR";
+ streamer.EmitBytes(Augmentation.str(), 0);
+ streamer.EmitIntValue(0, 1);
+
+ // Code Alignment Factor
+ streamer.EmitULEB128IntValue(1);
+
+ // Data Alignment Factor
+ streamer.EmitSLEB128IntValue(getDataAlignmentFactor(streamer));
+
+ // Return Address Register
+ streamer.EmitULEB128IntValue(asmInfo.getDwarfRARegNum(true));
+
+ // Augmentation Data Length (optional)
+ MCSymbol *augmentationStart = streamer.getContext().CreateTempSymbol();
+ MCSymbol *augmentationEnd = streamer.getContext().CreateTempSymbol();
+ const MCExpr *augmentationLength = MakeStartMinusEndExpr(streamer,
+ *augmentationStart,
+ *augmentationEnd, 0);
+ streamer.EmitULEB128Value(augmentationLength);
+
+ // Augmentation Data (optional)
+ streamer.EmitLabel(augmentationStart);
+ streamer.EmitIntValue(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4, 1);
+ streamer.EmitLabel(augmentationEnd);
+
+ // Initial Instructions
+
+ const std::vector<MachineMove> Moves = asmInfo.getInitialFrameState();
+
+ EmitFrameMoves(streamer, Moves, NULL, true);
+
+ // Padding
+ streamer.EmitValueToAlignment(asmInfo.getPointerSize());
+
+ streamer.EmitLabel(sectionEnd);
+ return *sectionStart;
+}
+
+static void EmitFDE(MCStreamer &streamer,
+ const MCSymbol &cieStart,
+ const MCDwarfFrameInfo &frame) {
+ MCContext &context = streamer.getContext();
+ const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ MCSymbol *fdeStart = streamer.getContext().CreateTempSymbol();
+ MCSymbol *fdeEnd = streamer.getContext().CreateTempSymbol();
+
+ // Length
+ const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0);
+ streamer.EmitValue(Length, 4);
+
+ streamer.EmitLabel(fdeStart);
+ // CIE Pointer
+ const MCExpr *offset = MakeStartMinusEndExpr(streamer, cieStart, *fdeStart,
+ 0);
+ streamer.EmitValue(offset, 4);
+
+ // PC Begin
+ streamer.EmitPCRelSymbolValue(frame.Begin, 4);
+
+ // PC Range
+ const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin,
+ *frame.End, 0);
+ streamer.EmitValue(Range, 4);
+
+ // Augmentation Data Length
+ streamer.EmitULEB128IntValue(0);
+
+ // Augmentation Data
+ // Call Frame Instructions
+
+ // Padding
+ streamer.EmitValueToAlignment(asmInfo.getPointerSize());
+ streamer.EmitLabel(fdeEnd);
+}
+
+void MCDwarfFrameEmitter::Emit(MCStreamer &streamer) {
+ const MCSymbol &cieStart = EmitCIE(streamer);
+ for (unsigned i = 0, n = streamer.getNumFrameInfos(); i < n; ++i)
+ EmitFDE(streamer, cieStart, streamer.getFrameInfo(i));
+}
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