| //===-- CodeGen/AsmPrinter/DwarfException.cpp - Dwarf Exception Impl ------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains support for writing DWARF exception info into asm files. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #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; |
| |
| // Map all labels and get rid of any dead landing pads. |
| MMI->TidyLandingPads(); |
| } |
| |
| DwarfCFIException::DwarfCFIException(AsmPrinter *A) |
| : DwarfCFIExceptionBase(A), shouldEmitPersonality(false), |
| shouldEmitLSDA(false), shouldEmitMoves(false), |
| moveTypeModule(AsmPrinter::CFI_M_None) {} |
| |
| DwarfCFIException::~DwarfCFIException() {} |
| |
| /// endModule - Emit all exception information that should come after the |
| /// content. |
| void DwarfCFIException::endModule() { |
| if (moveTypeModule == AsmPrinter::CFI_M_Debug) |
| Asm->OutStreamer->EmitCFISections(false, true); |
| |
| // SjLj uses this pass and it doesn't need this info. |
| if (!Asm->MAI->usesCFIForEH()) |
| return; |
| |
| const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); |
| |
| unsigned PerEncoding = TLOF.getPersonalityEncoding(); |
| |
| if ((PerEncoding & 0x80) != dwarf::DW_EH_PE_indirect) |
| return; |
| |
| // Emit references to all used personality functions |
| const std::vector<const Function*> &Personalities = MMI->getPersonalities(); |
| for (size_t i = 0, e = Personalities.size(); i != e; ++i) { |
| if (!Personalities[i]) |
| continue; |
| MCSymbol *Sym = Asm->getSymbol(Personalities[i]); |
| TLOF.emitPersonalityValue(*Asm->OutStreamer, Asm->TM, Sym); |
| } |
| } |
| |
| void DwarfCFIException::beginFunction(const MachineFunction *MF) { |
| shouldEmitMoves = shouldEmitPersonality = shouldEmitLSDA = false; |
| const Function *F = MF->getFunction(); |
| |
| // If any landing pads survive, we need an EH table. |
| bool hasLandingPads = !MMI->getLandingPads().empty(); |
| |
| // See if we need frame move info. |
| 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()); |
| assert(!MMI->getPersonality() || Per == MMI->getPersonality()); |
| |
| // Emit a personality function even when there are no landing pads |
| bool forceEmitPersonality = |
| // ...if a personality function is explicitly specified |
| F->hasPersonalityFn() && |
| // ... and it's not known to be a noop in the absence of invokes |
| !isNoOpWithoutInvoke(classifyEHPersonality(Per)) && |
| // ... and we're not explicitly asked not to emit it |
| 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(/*IsSimple=*/false); |
| |
| // Indicate personality routine, if any. |
| if (!shouldEmitPersonality) |
| return; |
| |
| // If we are forced to emit this personality, make sure to record |
| // it because it might not appear in any landingpad |
| if (forceEmitPersonality) |
| MMI->addPersonality(Per); |
| |
| const MCSymbol *Sym = |
| TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI); |
| Asm->OutStreamer->EmitCFIPersonality(Sym, PerEncoding); |
| |
| // Provide LSDA information. |
| if (!shouldEmitLSDA) |
| return; |
| |
| Asm->OutStreamer->EmitCFILsda(Asm->getCurExceptionSym(), LSDAEncoding); |
| } |
| |
| /// endFunction - Gather and emit post-function exception information. |
| /// |
| void DwarfCFIException::endFunction(const MachineFunction *) { |
| if (!shouldEmitPersonality) |
| return; |
| |
| emitExceptionTable(); |
| } |