diff options
Diffstat (limited to 'lib/CodeGen/AsmPrinter/DwarfException.cpp')
-rw-r--r-- | lib/CodeGen/AsmPrinter/DwarfException.cpp | 89 |
1 files changed, 67 insertions, 22 deletions
diff --git a/lib/CodeGen/AsmPrinter/DwarfException.cpp b/lib/CodeGen/AsmPrinter/DwarfException.cpp index 6c03b55..1c8b8f4 100644 --- a/lib/CodeGen/AsmPrinter/DwarfException.cpp +++ b/lib/CodeGen/AsmPrinter/DwarfException.cpp @@ -74,6 +74,25 @@ unsigned DwarfException::SizeOfEncodedValue(unsigned Encoding) { return 0; } +/// CreateLabelDiff - Emit a label and subtract it from the expression we +/// already have. This is equivalent to emitting "foo - .", but we have to emit +/// the label for "." directly. +const MCExpr *DwarfException::CreateLabelDiff(const MCExpr *ExprRef, + const char *LabelName, + unsigned Index) { + SmallString<64> Name; + raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() + << LabelName << Asm->getFunctionNumber() + << "_" << Index; + MCSymbol *DotSym = Asm->OutContext.GetOrCreateSymbol(Name.str()); + Asm->OutStreamer.EmitLabel(DotSym); + + return MCBinaryExpr::CreateSub(ExprRef, + MCSymbolRefExpr::Create(DotSym, + Asm->OutContext), + Asm->OutContext); +} + /// EmitCIE - Emit a Common Information Entry (CIE). This holds information that /// is shared among many Frame Description Entries. There is at least one CIE /// in every non-empty .debug_frame section. @@ -176,24 +195,10 @@ void DwarfException::EmitCIE(const Function *PersonalityFn, unsigned Index) { // If there is a personality, we need to indicate the function's location. if (PersonalityRef) { - // If the reference to the personality function symbol is not already - // pc-relative, then we need to subtract our current address from it. Do - // this by emitting a label and subtracting it from the expression we - // already have. This is equivalent to emitting "foo - .", but we have to - // emit the label for "." directly. - if (!IsPersonalityPCRel) { - SmallString<64> Name; - raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() - << "personalityref_addr" << Asm->getFunctionNumber() << "_" << Index; - MCSymbol *DotSym = Asm->OutContext.GetOrCreateSymbol(Name.str()); - Asm->OutStreamer.EmitLabel(DotSym); - - PersonalityRef = - MCBinaryExpr::CreateSub(PersonalityRef, - MCSymbolRefExpr::Create(DotSym,Asm->OutContext), - Asm->OutContext); - } - + if (!IsPersonalityPCRel) + PersonalityRef = CreateLabelDiff(PersonalityRef, "personalityref_addr", + Index); + O << MAI->getData32bitsDirective(); PersonalityRef->print(O, MAI); Asm->EOL("Personality"); @@ -232,11 +237,16 @@ void DwarfException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) { // corresponding function is static, this should not be externally visible. if (!TheFunc->hasLocalLinkage()) if (const char *GlobalEHDirective = MAI->getGlobalEHDirective()) - O << GlobalEHDirective << EHFrameInfo.FnName << "\n"; + O << GlobalEHDirective << EHFrameInfo.FnName << '\n'; // If corresponding function is weak definition, this should be too. if (TheFunc->isWeakForLinker() && MAI->getWeakDefDirective()) - O << MAI->getWeakDefDirective() << EHFrameInfo.FnName << "\n"; + O << MAI->getWeakDefDirective() << EHFrameInfo.FnName << '\n'; + + // If corresponding function is hidden, this should be too. + if (TheFunc->hasHiddenVisibility()) + if (const char *HiddenDirective = MAI->getHiddenDirective()) + O << HiddenDirective << EHFrameInfo.FnName << '\n' ; // If there are no calls then you can't unwind. This may mean we can omit the // EH Frame, but some environments do not handle weak absolute symbols. If @@ -457,6 +467,39 @@ ComputeActionsTable(const SmallVectorImpl<const LandingPadInfo*> &LandingPads, return SizeActions; } +/// CallToNoUnwindFunction - Return `true' if this is a call to a function +/// marked `nounwind'. Return `false' otherwise. +bool DwarfException::CallToNoUnwindFunction(const MachineInstr *MI) { + assert(MI->getDesc().isCall() && "This should be a call instruction!"); + + bool MarkedNoUnwind = false; + bool SawFunc = false; + + for (unsigned I = 0, E = MI->getNumOperands(); I != E; ++I) { + const MachineOperand &MO = MI->getOperand(I); + + if (MO.isGlobal()) { + if (Function *F = dyn_cast<Function>(MO.getGlobal())) { + if (SawFunc) { + // Be conservative. If we have more than one function operand for this + // call, then we can't make the assumption that it's the callee and + // not a parameter to the call. + // + // FIXME: Determine if there's a way to say that `F' is the callee or + // parameter. + MarkedNoUnwind = false; + break; + } + + MarkedNoUnwind = F->doesNotThrow(); + SawFunc = true; + } + } + } + + return MarkedNoUnwind; +} + /// ComputeCallSiteTable - Compute the call-site table. The entry for an invoke /// has a try-range containing the call, a non-zero landing pad, and an /// appropriate action. The entry for an ordinary call has a try-range @@ -485,7 +528,9 @@ ComputeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites, for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end(); MI != E; ++MI) { if (!MI->isLabel()) { - SawPotentiallyThrowing |= MI->getDesc().isCall(); + if (MI->getDesc().isCall()) + SawPotentiallyThrowing |= !CallToNoUnwindFunction(MI); + continue; } @@ -497,7 +542,7 @@ ComputeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites, SawPotentiallyThrowing = false; // Beginning of a new try-range? - RangeMapType::iterator L = PadMap.find(BeginLabel); + RangeMapType::const_iterator L = PadMap.find(BeginLabel); if (L == PadMap.end()) // Nope, it was just some random label. continue; |