DwarfCFIException.cpp [plain text]
#include "DwarfException.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MachineLocation.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
DwarfCFIExceptionBase::DwarfCFIExceptionBase(AsmPrinter *A)
: EHStreamer(A), shouldEmitCFI(false) {}
void DwarfCFIExceptionBase::markFunctionEnd() {
if (shouldEmitCFI)
Asm->OutStreamer->EmitCFIEndProc();
if (MMI->getLandingPads().empty())
return;
MMI->TidyLandingPads();
}
DwarfCFIException::DwarfCFIException(AsmPrinter *A)
: DwarfCFIExceptionBase(A), shouldEmitPersonality(false),
shouldEmitLSDA(false), shouldEmitMoves(false),
moveTypeModule(AsmPrinter::CFI_M_None) {}
DwarfCFIException::~DwarfCFIException() {}
void DwarfCFIException::endModule() {
if (moveTypeModule == AsmPrinter::CFI_M_Debug)
Asm->OutStreamer->EmitCFISections(false, true);
if (!Asm->MAI->usesCFIForEH())
return;
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
unsigned PerEncoding = TLOF.getPersonalityEncoding();
if ((PerEncoding & 0x80) != dwarf::DW_EH_PE_indirect)
return;
for (const Function *Personality : MMI->getPersonalities()) {
if (!Personality)
continue;
MCSymbol *Sym = Asm->getSymbol(Personality);
TLOF.emitPersonalityValue(*Asm->OutStreamer, Asm->getDataLayout(), Sym);
}
}
void DwarfCFIException::beginFunction(const MachineFunction *MF) {
shouldEmitMoves = shouldEmitPersonality = shouldEmitLSDA = false;
const Function *F = MF->getFunction();
bool hasLandingPads = !MMI->getLandingPads().empty();
AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
if (MoveType == AsmPrinter::CFI_M_EH ||
(MoveType == AsmPrinter::CFI_M_Debug &&
moveTypeModule == AsmPrinter::CFI_M_None))
moveTypeModule = MoveType;
shouldEmitMoves = MoveType != AsmPrinter::CFI_M_None;
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
unsigned PerEncoding = TLOF.getPersonalityEncoding();
const Function *Per = nullptr;
if (F->hasPersonalityFn())
Per = dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts());
bool forceEmitPersonality =
F->hasPersonalityFn() &&
!isNoOpWithoutInvoke(classifyEHPersonality(Per)) &&
F->needsUnwindTableEntry();
shouldEmitPersonality =
(forceEmitPersonality ||
(hasLandingPads && PerEncoding != dwarf::DW_EH_PE_omit)) &&
Per;
unsigned LSDAEncoding = TLOF.getLSDAEncoding();
shouldEmitLSDA = shouldEmitPersonality &&
LSDAEncoding != dwarf::DW_EH_PE_omit;
shouldEmitCFI = shouldEmitPersonality || shouldEmitMoves;
if (!shouldEmitCFI)
return;
Asm->OutStreamer->EmitCFIStartProc(false);
if (!shouldEmitPersonality)
return;
if (forceEmitPersonality)
MMI->addPersonality(Per);
const MCSymbol *Sym =
TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
Asm->OutStreamer->EmitCFIPersonality(Sym, PerEncoding);
if (!shouldEmitLSDA)
return;
Asm->OutStreamer->EmitCFILsda(Asm->getCurExceptionSym(), LSDAEncoding);
}
void DwarfCFIException::endFunction(const MachineFunction *) {
if (!shouldEmitPersonality)
return;
emitExceptionTable();
}