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-rw-r--r--lib/MC/MCDwarf.cpp135
1 files changed, 47 insertions, 88 deletions
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 0f8f074..21ccc3e 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -16,7 +16,6 @@
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectFileInfo.h"
-#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
@@ -47,20 +46,15 @@ using namespace llvm;
// Range of line offsets in a special line info. opcode.
#define DWARF2_LINE_RANGE 14
-// Define the architecture-dependent minimum instruction length (in bytes).
-// This value should be rather too small than too big.
-#define DWARF2_LINE_MIN_INSN_LENGTH 1
-
-// Note: when DWARF2_LINE_MIN_INSN_LENGTH == 1 which is the current setting,
-// this routine is a nop and will be optimized away.
-static inline uint64_t ScaleAddrDelta(uint64_t AddrDelta) {
- if (DWARF2_LINE_MIN_INSN_LENGTH == 1)
+static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) {
+ unsigned MinInsnLength = Context.getAsmInfo().getMinInstAlignment();
+ if (MinInsnLength == 1)
return AddrDelta;
- if (AddrDelta % DWARF2_LINE_MIN_INSN_LENGTH != 0) {
+ if (AddrDelta % MinInsnLength != 0) {
// TODO: report this error, but really only once.
;
}
- return AddrDelta / DWARF2_LINE_MIN_INSN_LENGTH;
+ return AddrDelta / MinInsnLength;
}
//
@@ -197,6 +191,8 @@ static inline void EmitDwarfLineTable(MCStreamer *MCOS,
// actually a DW_LNE_end_sequence.
// Switch to the section to be able to create a symbol at its end.
+ // TODO: keep track of the last subsection so that this symbol appears in the
+ // correct place.
MCOS->SwitchSection(Section);
MCContext &context = MCOS->getContext();
@@ -275,7 +271,7 @@ const MCSymbol *MCDwarfFileTable::EmitCU(MCStreamer *MCOS, unsigned CUID) {
(4 + 2 + 4)), 4, 0);
// Parameters of the state machine, are next.
- MCOS->EmitIntValue(DWARF2_LINE_MIN_INSN_LENGTH, 1);
+ MCOS->EmitIntValue(context.getAsmInfo().getMinInstAlignment(), 1);
MCOS->EmitIntValue(DWARF2_LINE_DEFAULT_IS_STMT, 1);
MCOS->EmitIntValue(DWARF2_LINE_BASE, 1);
MCOS->EmitIntValue(DWARF2_LINE_RANGE, 1);
@@ -355,32 +351,24 @@ const MCSymbol *MCDwarfFileTable::EmitCU(MCStreamer *MCOS, unsigned CUID) {
return LineStartSym;
}
-/// Utility function to write the encoding to an object writer.
-void MCDwarfLineAddr::Write(MCObjectWriter *OW, int64_t LineDelta,
- uint64_t AddrDelta) {
- SmallString<256> Tmp;
- raw_svector_ostream OS(Tmp);
- MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OS);
- OW->WriteBytes(OS.str());
-}
-
/// Utility function to emit the encoding to a streamer.
void MCDwarfLineAddr::Emit(MCStreamer *MCOS, int64_t LineDelta,
uint64_t AddrDelta) {
+ MCContext &Context = MCOS->getContext();
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
- MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OS);
+ MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OS);
MCOS->EmitBytes(OS.str());
}
/// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas.
-void MCDwarfLineAddr::Encode(int64_t LineDelta, uint64_t AddrDelta,
- raw_ostream &OS) {
+void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta,
+ uint64_t AddrDelta, raw_ostream &OS) {
uint64_t Temp, Opcode;
bool NeedCopy = false;
// Scale the address delta by the minimum instruction length.
- AddrDelta = ScaleAddrDelta(AddrDelta);
+ AddrDelta = ScaleAddrDelta(Context, AddrDelta);
// A LineDelta of INT64_MAX is a signal that this is actually a
// DW_LNE_end_sequence. We cannot use special opcodes here, since we want the
@@ -787,7 +775,7 @@ void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS,
if (Symbol->isTemporary())
return;
MCContext &context = MCOS->getContext();
- if (context.getGenDwarfSection() != MCOS->getCurrentSection())
+ if (context.getGenDwarfSection() != MCOS->getCurrentSection().first)
return;
// The dwarf label's name does not have the symbol name's leading
@@ -871,17 +859,6 @@ static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol,
streamer.EmitValue(v, size);
}
-static const MachineLocation TranslateMachineLocation(
- const MCRegisterInfo &MRI,
- const MachineLocation &Loc) {
- unsigned Reg = Loc.getReg() == MachineLocation::VirtualFP ?
- MachineLocation::VirtualFP :
- unsigned(MRI.getDwarfRegNum(Loc.getReg(), true));
- const MachineLocation &NewLoc = Loc.isReg() ?
- MachineLocation(Reg) : MachineLocation(Reg, Loc.getOffset());
- return NewLoc;
-}
-
namespace {
class FrameEmitterImpl {
int CFAOffset;
@@ -899,7 +876,7 @@ namespace {
/// EmitCompactUnwind - Emit the unwind information in a compact way. If
/// we're successful, return 'true'. Otherwise, return 'false' and it will
/// emit the normal CIE and FDE.
- bool EmitCompactUnwind(MCStreamer &streamer,
+ void EmitCompactUnwind(MCStreamer &streamer,
const MCDwarfFrameInfo &frame);
const MCSymbol &EmitCIE(MCStreamer &streamer,
@@ -1139,7 +1116,7 @@ void FrameEmitterImpl::EmitCFIInstructions(MCStreamer &streamer,
/// EmitCompactUnwind - Emit the unwind information in a compact way. If we're
/// successful, return 'true'. Otherwise, return 'false' and it will emit the
/// normal CIE and FDE.
-bool FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
+void FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
const MCDwarfFrameInfo &Frame) {
MCContext &Context = Streamer.getContext();
const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
@@ -1168,14 +1145,13 @@ bool FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
// .quad except_tab1
uint32_t Encoding = Frame.CompactUnwindEncoding;
- if (!Encoding) return false;
+ if (!Encoding) return;
+ bool DwarfEHFrameOnly = (Encoding == MOFI->getCompactUnwindDwarfEHFrameOnly());
// The encoding needs to know we have an LSDA.
- if (Frame.Lsda)
+ if (!DwarfEHFrameOnly && Frame.Lsda)
Encoding |= 0x40000000;
- Streamer.SwitchSection(MOFI->getCompactUnwindSection());
-
// Range Start
unsigned FDEEncoding = MOFI->getFDEEncoding(UsingCFI);
unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
@@ -1194,11 +1170,10 @@ bool FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
Twine::utohexstr(Encoding));
Streamer.EmitIntValue(Encoding, Size);
-
// Personality Function
Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr);
if (VerboseAsm) Streamer.AddComment("Personality Function");
- if (Frame.Personality)
+ if (!DwarfEHFrameOnly && Frame.Personality)
Streamer.EmitSymbolValue(Frame.Personality, Size);
else
Streamer.EmitIntValue(0, Size); // No personality fn
@@ -1206,12 +1181,10 @@ bool FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
// LSDA
Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding);
if (VerboseAsm) Streamer.AddComment("LSDA");
- if (Frame.Lsda)
+ if (!DwarfEHFrameOnly && Frame.Lsda)
Streamer.EmitSymbolValue(Frame.Lsda, Size);
else
Streamer.EmitIntValue(0, Size); // No LSDA
-
- return true;
}
const MCSymbol &FrameEmitterImpl::EmitCIE(MCStreamer &streamer,
@@ -1269,7 +1242,7 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCStreamer &streamer,
// Code Alignment Factor
if (verboseAsm) streamer.AddComment("CIE Code Alignment Factor");
- streamer.EmitULEB128IntValue(1);
+ streamer.EmitULEB128IntValue(context.getAsmInfo().getMinInstAlignment());
// Data Alignment Factor
if (verboseAsm) streamer.AddComment("CIE Data Alignment Factor");
@@ -1318,32 +1291,8 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCStreamer &streamer,
// Initial Instructions
const MCAsmInfo &MAI = context.getAsmInfo();
- const std::vector<MachineMove> &Moves = MAI.getInitialFrameState();
- std::vector<MCCFIInstruction> Instructions;
-
- for (int i = 0, n = Moves.size(); i != n; ++i) {
- MCSymbol *Label = Moves[i].getLabel();
- const MachineLocation &Dst =
- TranslateMachineLocation(MRI, Moves[i].getDestination());
- const MachineLocation &Src =
- TranslateMachineLocation(MRI, Moves[i].getSource());
-
- if (Dst.isReg()) {
- assert(Dst.getReg() == MachineLocation::VirtualFP);
- assert(!Src.isReg());
- MCCFIInstruction Inst =
- MCCFIInstruction::createDefCfa(Label, Src.getReg(), -Src.getOffset());
- Instructions.push_back(Inst);
- } else {
- assert(Src.isReg());
- unsigned Reg = Src.getReg();
- int Offset = Dst.getOffset();
- MCCFIInstruction Inst =
- MCCFIInstruction::createOffset(Label, Reg, Offset);
- Instructions.push_back(Inst);
- }
- }
-
+ const std::vector<MCCFIInstruction> &Instructions =
+ MAI.getInitialFrameState();
EmitCFIInstructions(streamer, Instructions, NULL);
// Padding
@@ -1421,7 +1370,6 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer,
}
// Call Frame Instructions
-
EmitCFIInstructions(streamer, frame.Instructions, frame.Begin);
// Padding
@@ -1476,21 +1424,28 @@ void MCDwarfFrameEmitter::Emit(MCStreamer &Streamer,
bool UsingCFI,
bool IsEH) {
MCContext &Context = Streamer.getContext();
- MCObjectFileInfo *MOFI =
- const_cast<MCObjectFileInfo*>(Context.getObjectFileInfo());
+ const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
FrameEmitterImpl Emitter(UsingCFI, IsEH);
ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getFrameInfos();
// Emit the compact unwind info if available.
- if (IsEH && MOFI->getCompactUnwindSection())
- for (unsigned i = 0, n = Streamer.getNumFrameInfos(); i < n; ++i) {
- const MCDwarfFrameInfo &Frame = Streamer.getFrameInfo(i);
- if (Frame.CompactUnwindEncoding)
- Emitter.EmitCompactUnwind(Streamer, Frame);
+ if (IsEH && MOFI->getCompactUnwindSection()) {
+ bool SectionEmitted = false;
+ for (unsigned i = 0, n = FrameArray.size(); i < n; ++i) {
+ const MCDwarfFrameInfo &Frame = FrameArray[i];
+ if (Frame.CompactUnwindEncoding == 0) continue;
+ if (!SectionEmitted) {
+ Streamer.SwitchSection(MOFI->getCompactUnwindSection());
+ Streamer.EmitValueToAlignment(Context.getAsmInfo().getPointerSize());
+ SectionEmitted = true;
+ }
+ Emitter.EmitCompactUnwind(Streamer, Frame);
}
+ }
- const MCSection &Section = IsEH ? *MOFI->getEHFrameSection() :
- *MOFI->getDwarfFrameSection();
+ const MCSection &Section =
+ IsEH ? *const_cast<MCObjectFileInfo*>(MOFI)->getEHFrameSection() :
+ *MOFI->getDwarfFrameSection();
Streamer.SwitchSection(&Section);
MCSymbol *SectionStart = Context.CreateTempSymbol();
Streamer.EmitLabel(SectionStart);
@@ -1524,15 +1479,19 @@ void MCDwarfFrameEmitter::Emit(MCStreamer &Streamer,
void MCDwarfFrameEmitter::EmitAdvanceLoc(MCStreamer &Streamer,
uint64_t AddrDelta) {
+ MCContext &Context = Streamer.getContext();
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
- MCDwarfFrameEmitter::EncodeAdvanceLoc(AddrDelta, OS);
+ MCDwarfFrameEmitter::EncodeAdvanceLoc(Context, AddrDelta, OS);
Streamer.EmitBytes(OS.str());
}
-void MCDwarfFrameEmitter::EncodeAdvanceLoc(uint64_t AddrDelta,
+void MCDwarfFrameEmitter::EncodeAdvanceLoc(MCContext &Context,
+ uint64_t AddrDelta,
raw_ostream &OS) {
- // FIXME: Assumes the code alignment factor is 1.
+ // Scale the address delta by the minimum instruction length.
+ AddrDelta = ScaleAddrDelta(Context, AddrDelta);
+
if (AddrDelta == 0) {
} else if (isUIntN(6, AddrDelta)) {
uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
generated by cgit v1.1 at 2025-07-04 02:42:43 +0000