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Diffstat (limited to 'lib/CodeGen/AsmPrinter/DwarfException.cpp')
| -rw-r--r-- | lib/CodeGen/AsmPrinter/DwarfException.cpp | 706 |
1 files changed, 706 insertions, 0 deletions
diff --git a/lib/CodeGen/AsmPrinter/DwarfException.cpp b/lib/CodeGen/AsmPrinter/DwarfException.cpp new file mode 100644 index 0000000..37466ab --- /dev/null +++ b/lib/CodeGen/AsmPrinter/DwarfException.cpp @@ -0,0 +1,706 @@ +//===-- 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/Module.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineLocation.h" +#include "llvm/Support/Dwarf.h" +#include "llvm/Support/Timer.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetAsmInfo.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetData.h" +#include "llvm/Target/TargetFrameInfo.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/ADT/StringExtras.h" +using namespace llvm; + +static TimerGroup &getDwarfTimerGroup() { + static TimerGroup DwarfTimerGroup("Dwarf Exception"); + return DwarfTimerGroup; +} + +DwarfException::DwarfException(raw_ostream &OS, AsmPrinter *A, + const TargetAsmInfo *T) + : Dwarf(OS, A, T, "eh"), shouldEmitTable(false), shouldEmitMoves(false), + shouldEmitTableModule(false), shouldEmitMovesModule(false), + ExceptionTimer(0) { + if (TimePassesIsEnabled) + ExceptionTimer = new Timer("Dwarf Exception Writer", + getDwarfTimerGroup()); +} + +DwarfException::~DwarfException() { + delete ExceptionTimer; +} + +void DwarfException::EmitCommonEHFrame(const Function *Personality, + unsigned Index) { + // Size and sign of stack growth. + int stackGrowth = + Asm->TM.getFrameInfo()->getStackGrowthDirection() == + TargetFrameInfo::StackGrowsUp ? + TD->getPointerSize() : -TD->getPointerSize(); + + // Begin eh frame section. + Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection()); + + if (!TAI->doesRequireNonLocalEHFrameLabel()) + O << TAI->getEHGlobalPrefix(); + + O << "EH_frame" << Index << ":\n"; + EmitLabel("section_eh_frame", Index); + + // Define base labels. + EmitLabel("eh_frame_common", Index); + + // Define the eh frame length. + EmitDifference("eh_frame_common_end", Index, + "eh_frame_common_begin", Index, true); + Asm->EOL("Length of Common Information Entry"); + + // EH frame header. + EmitLabel("eh_frame_common_begin", Index); + Asm->EmitInt32((int)0); + Asm->EOL("CIE Identifier Tag"); + Asm->EmitInt8(dwarf::DW_CIE_VERSION); + Asm->EOL("CIE Version"); + + // The personality presence indicates that language specific information will + // show up in the eh frame. + Asm->EmitString(Personality ? "zPLR" : "zR"); + Asm->EOL("CIE Augmentation"); + + // Round out reader. + Asm->EmitULEB128Bytes(1); + Asm->EOL("CIE Code Alignment Factor"); + Asm->EmitSLEB128Bytes(stackGrowth); + Asm->EOL("CIE Data Alignment Factor"); + Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true)); + Asm->EOL("CIE Return Address Column"); + + // If there is a personality, we need to indicate the functions location. + if (Personality) { + Asm->EmitULEB128Bytes(7); + Asm->EOL("Augmentation Size"); + + if (TAI->getNeedsIndirectEncoding()) { + Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 | + dwarf::DW_EH_PE_indirect); + Asm->EOL("Personality (pcrel sdata4 indirect)"); + } else { + Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4); + Asm->EOL("Personality (pcrel sdata4)"); + } + + PrintRelDirective(true); + O << TAI->getPersonalityPrefix(); + Asm->EmitExternalGlobal((const GlobalVariable *)(Personality)); + O << TAI->getPersonalitySuffix(); + if (strcmp(TAI->getPersonalitySuffix(), "+4@GOTPCREL")) + O << "-" << TAI->getPCSymbol(); + Asm->EOL("Personality"); + + Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4); + Asm->EOL("LSDA Encoding (pcrel sdata4)"); + + Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4); + Asm->EOL("FDE Encoding (pcrel sdata4)"); + } else { + Asm->EmitULEB128Bytes(1); + Asm->EOL("Augmentation Size"); + + Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4); + Asm->EOL("FDE Encoding (pcrel sdata4)"); + } + + // Indicate locations of general callee saved registers in frame. + std::vector<MachineMove> Moves; + RI->getInitialFrameState(Moves); + EmitFrameMoves(NULL, 0, Moves, true); + + // On Darwin the linker honors the alignment of eh_frame, which means it must + // be 8-byte on 64-bit targets to match what gcc does. Otherwise you get + // holes which confuse readers of eh_frame. + Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3, + 0, 0, false); + EmitLabel("eh_frame_common_end", Index); + + Asm->EOL(); +} + +/// EmitEHFrame - Emit function exception frame information. +/// +void DwarfException::EmitEHFrame(const FunctionEHFrameInfo &EHFrameInfo) { + assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() && + "Should not emit 'available externally' functions at all"); + + Function::LinkageTypes linkage = EHFrameInfo.function->getLinkage(); + Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection()); + + // Externally visible entry into the functions eh frame info. If the + // corresponding function is static, this should not be externally visible. + if (linkage != Function::InternalLinkage && + linkage != Function::PrivateLinkage) { + if (const char *GlobalEHDirective = TAI->getGlobalEHDirective()) + O << GlobalEHDirective << EHFrameInfo.FnName << "\n"; + } + + // If corresponding function is weak definition, this should be too. + if ((linkage == Function::WeakAnyLinkage || + linkage == Function::WeakODRLinkage || + linkage == Function::LinkOnceAnyLinkage || + linkage == Function::LinkOnceODRLinkage) && + TAI->getWeakDefDirective()) + O << TAI->getWeakDefDirective() << 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 + // UnwindTablesMandatory is set we cannot do this optimization; the unwind + // info is to be available for non-EH uses. + if (!EHFrameInfo.hasCalls && + !UnwindTablesMandatory && + ((linkage != Function::WeakAnyLinkage && + linkage != Function::WeakODRLinkage && + linkage != Function::LinkOnceAnyLinkage && + linkage != Function::LinkOnceODRLinkage) || + !TAI->getWeakDefDirective() || + TAI->getSupportsWeakOmittedEHFrame())) { + O << EHFrameInfo.FnName << " = 0\n"; + // This name has no connection to the function, so it might get + // dead-stripped when the function is not, erroneously. Prohibit + // dead-stripping unconditionally. + if (const char *UsedDirective = TAI->getUsedDirective()) + O << UsedDirective << EHFrameInfo.FnName << "\n\n"; + } else { + O << EHFrameInfo.FnName << ":\n"; + + // EH frame header. + EmitDifference("eh_frame_end", EHFrameInfo.Number, + "eh_frame_begin", EHFrameInfo.Number, true); + Asm->EOL("Length of Frame Information Entry"); + + EmitLabel("eh_frame_begin", EHFrameInfo.Number); + + if (TAI->doesRequireNonLocalEHFrameLabel()) { + PrintRelDirective(true, true); + PrintLabelName("eh_frame_begin", EHFrameInfo.Number); + + if (!TAI->isAbsoluteEHSectionOffsets()) + O << "-EH_frame" << EHFrameInfo.PersonalityIndex; + } else { + EmitSectionOffset("eh_frame_begin", "eh_frame_common", + EHFrameInfo.Number, EHFrameInfo.PersonalityIndex, + true, true, false); + } + + Asm->EOL("FDE CIE offset"); + + EmitReference("eh_func_begin", EHFrameInfo.Number, true, true); + Asm->EOL("FDE initial location"); + EmitDifference("eh_func_end", EHFrameInfo.Number, + "eh_func_begin", EHFrameInfo.Number, true); + Asm->EOL("FDE address range"); + + // If there is a personality and landing pads then point to the language + // specific data area in the exception table. + if (EHFrameInfo.PersonalityIndex) { + Asm->EmitULEB128Bytes(4); + Asm->EOL("Augmentation size"); + + if (EHFrameInfo.hasLandingPads) + EmitReference("exception", EHFrameInfo.Number, true, true); + else + Asm->EmitInt32((int)0); + Asm->EOL("Language Specific Data Area"); + } else { + Asm->EmitULEB128Bytes(0); + Asm->EOL("Augmentation size"); + } + + // Indicate locations of function specific callee saved registers in frame. + EmitFrameMoves("eh_func_begin", EHFrameInfo.Number, EHFrameInfo.Moves, + true); + + // On Darwin the linker honors the alignment of eh_frame, which means it + // must be 8-byte on 64-bit targets to match what gcc does. Otherwise you + // get holes which confuse readers of eh_frame. + Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3, + 0, 0, false); + EmitLabel("eh_frame_end", EHFrameInfo.Number); + + // If the function is marked used, this table should be also. We cannot + // make the mark unconditional in this case, since retaining the table also + // retains the function in this case, and there is code around that depends + // on unused functions (calling undefined externals) being dead-stripped to + // link correctly. Yes, there really is. + if (MMI->getUsedFunctions().count(EHFrameInfo.function)) + if (const char *UsedDirective = TAI->getUsedDirective()) + O << UsedDirective << EHFrameInfo.FnName << "\n\n"; + } +} + +/// EmitExceptionTable - Emit landing pads and actions. +/// +/// The general organization of the table is complex, but the basic concepts are +/// easy. First there is a header which describes the location and organization +/// of the three components that follow. +/// +/// 1. The landing pad site information describes the range of code covered by +/// the try. In our case it's an accumulation of the ranges covered by the +/// invokes in the try. There is also a reference to the landing pad that +/// handles the exception once processed. Finally an index into the actions +/// table. +/// 2. The action table, in our case, is composed of pairs of type ids and next +/// action offset. Starting with the action index from the landing pad +/// site, each type Id is checked for a match to the current exception. If +/// it matches then the exception and type id are passed on to the landing +/// pad. Otherwise the next action is looked up. This chain is terminated +/// with a next action of zero. If no type id is found the the frame is +/// unwound and handling continues. +/// 3. Type id table contains references to all the C++ typeinfo for all +/// catches in the function. This tables is reversed indexed base 1. + +/// SharedTypeIds - How many leading type ids two landing pads have in common. +unsigned DwarfException::SharedTypeIds(const LandingPadInfo *L, + const LandingPadInfo *R) { + const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds; + unsigned LSize = LIds.size(), RSize = RIds.size(); + unsigned MinSize = LSize < RSize ? LSize : RSize; + unsigned Count = 0; + + for (; Count != MinSize; ++Count) + if (LIds[Count] != RIds[Count]) + return Count; + + return Count; +} + +/// PadLT - Order landing pads lexicographically by type id. +bool DwarfException::PadLT(const LandingPadInfo *L, const LandingPadInfo *R) { + const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds; + unsigned LSize = LIds.size(), RSize = RIds.size(); + unsigned MinSize = LSize < RSize ? LSize : RSize; + + for (unsigned i = 0; i != MinSize; ++i) + if (LIds[i] != RIds[i]) + return LIds[i] < RIds[i]; + + return LSize < RSize; +} + +void DwarfException::EmitExceptionTable() { + const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos(); + const std::vector<unsigned> &FilterIds = MMI->getFilterIds(); + const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads(); + if (PadInfos.empty()) return; + + // Sort the landing pads in order of their type ids. This is used to fold + // duplicate actions. + SmallVector<const LandingPadInfo *, 64> LandingPads; + LandingPads.reserve(PadInfos.size()); + for (unsigned i = 0, N = PadInfos.size(); i != N; ++i) + LandingPads.push_back(&PadInfos[i]); + std::sort(LandingPads.begin(), LandingPads.end(), PadLT); + + // Negative type ids index into FilterIds, positive type ids index into + // TypeInfos. The value written for a positive type id is just the type id + // itself. For a negative type id, however, the value written is the + // (negative) byte offset of the corresponding FilterIds entry. The byte + // offset is usually equal to the type id, because the FilterIds entries are + // written using a variable width encoding which outputs one byte per entry as + // long as the value written is not too large, but can differ. This kind of + // complication does not occur for positive type ids because type infos are + // output using a fixed width encoding. FilterOffsets[i] holds the byte + // offset corresponding to FilterIds[i]. + SmallVector<int, 16> FilterOffsets; + FilterOffsets.reserve(FilterIds.size()); + int Offset = -1; + for(std::vector<unsigned>::const_iterator I = FilterIds.begin(), + E = FilterIds.end(); I != E; ++I) { + FilterOffsets.push_back(Offset); + Offset -= TargetAsmInfo::getULEB128Size(*I); + } + + // Compute the actions table and gather the first action index for each + // landing pad site. + SmallVector<ActionEntry, 32> Actions; + SmallVector<unsigned, 64> FirstActions; + FirstActions.reserve(LandingPads.size()); + + int FirstAction = 0; + unsigned SizeActions = 0; + for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) { + const LandingPadInfo *LP = LandingPads[i]; + const std::vector<int> &TypeIds = LP->TypeIds; + const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0; + unsigned SizeSiteActions = 0; + + if (NumShared < TypeIds.size()) { + unsigned SizeAction = 0; + ActionEntry *PrevAction = 0; + + if (NumShared) { + const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size(); + assert(Actions.size()); + PrevAction = &Actions.back(); + SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) + + TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID); + + for (unsigned j = NumShared; j != SizePrevIds; ++j) { + SizeAction -= + TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID); + SizeAction += -PrevAction->NextAction; + PrevAction = PrevAction->Previous; + } + } + + // Compute the actions. + for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) { + int TypeID = TypeIds[I]; + assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!"); + int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID; + unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID); + + int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0; + SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction); + SizeSiteActions += SizeAction; + + ActionEntry Action = {ValueForTypeID, NextAction, PrevAction}; + Actions.push_back(Action); + + PrevAction = &Actions.back(); + } + + // Record the first action of the landing pad site. + FirstAction = SizeActions + SizeSiteActions - SizeAction + 1; + } // else identical - re-use previous FirstAction + + FirstActions.push_back(FirstAction); + + // Compute this sites contribution to size. + SizeActions += SizeSiteActions; + } + + // 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 containing the call and zero for + // the landing pad and the action. Calls marked 'nounwind' have no entry and + // must not be contained in the try-range of any entry - they form gaps in the + // table. Entries must be ordered by try-range address. + SmallVector<CallSiteEntry, 64> CallSites; + + RangeMapType PadMap; + + // Invokes and nounwind calls have entries in PadMap (due to being bracketed + // by try-range labels when lowered). Ordinary calls do not, so appropriate + // try-ranges for them need be deduced. + for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) { + const LandingPadInfo *LandingPad = LandingPads[i]; + for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) { + unsigned BeginLabel = LandingPad->BeginLabels[j]; + assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!"); + PadRange P = { i, j }; + PadMap[BeginLabel] = P; + } + } + + // The end label of the previous invoke or nounwind try-range. + unsigned LastLabel = 0; + + // Whether there is a potentially throwing instruction (currently this means + // an ordinary call) between the end of the previous try-range and now. + bool SawPotentiallyThrowing = false; + + // Whether the last callsite entry was for an invoke. + bool PreviousIsInvoke = false; + + // Visit all instructions in order of address. + for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); + I != E; ++I) { + for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end(); + MI != E; ++MI) { + if (!MI->isLabel()) { + SawPotentiallyThrowing |= MI->getDesc().isCall(); + continue; + } + + unsigned BeginLabel = MI->getOperand(0).getImm(); + assert(BeginLabel && "Invalid label!"); + + // End of the previous try-range? + if (BeginLabel == LastLabel) + SawPotentiallyThrowing = false; + + // Beginning of a new try-range? + RangeMapType::iterator L = PadMap.find(BeginLabel); + if (L == PadMap.end()) + // Nope, it was just some random label. + continue; + + PadRange P = L->second; + const LandingPadInfo *LandingPad = LandingPads[P.PadIndex]; + + assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] && + "Inconsistent landing pad map!"); + + // If some instruction between the previous try-range and this one may + // throw, create a call-site entry with no landing pad for the region + // between the try-ranges. + if (SawPotentiallyThrowing) { + CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0}; + CallSites.push_back(Site); + PreviousIsInvoke = false; + } + + LastLabel = LandingPad->EndLabels[P.RangeIndex]; + assert(BeginLabel && LastLabel && "Invalid landing pad!"); + + if (LandingPad->LandingPadLabel) { + // This try-range is for an invoke. + CallSiteEntry Site = {BeginLabel, LastLabel, + LandingPad->LandingPadLabel, + FirstActions[P.PadIndex]}; + + // Try to merge with the previous call-site. + if (PreviousIsInvoke) { + CallSiteEntry &Prev = CallSites.back(); + if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) { + // Extend the range of the previous entry. + Prev.EndLabel = Site.EndLabel; + continue; + } + } + + // Otherwise, create a new call-site. + CallSites.push_back(Site); + PreviousIsInvoke = true; + } else { + // Create a gap. + PreviousIsInvoke = false; + } + } + } + + // If some instruction between the previous try-range and the end of the + // function may throw, create a call-site entry with no landing pad for the + // region following the try-range. + if (SawPotentiallyThrowing) { + CallSiteEntry Site = {LastLabel, 0, 0, 0}; + CallSites.push_back(Site); + } + + // Final tallies. + + // Call sites. + const unsigned SiteStartSize = sizeof(int32_t); // DW_EH_PE_udata4 + const unsigned SiteLengthSize = sizeof(int32_t); // DW_EH_PE_udata4 + const unsigned LandingPadSize = sizeof(int32_t); // DW_EH_PE_udata4 + unsigned SizeSites = CallSites.size() * (SiteStartSize + + SiteLengthSize + + LandingPadSize); + for (unsigned i = 0, e = CallSites.size(); i < e; ++i) + SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action); + + // Type infos. + const unsigned TypeInfoSize = TD->getPointerSize(); // DW_EH_PE_absptr + unsigned SizeTypes = TypeInfos.size() * TypeInfoSize; + + unsigned TypeOffset = sizeof(int8_t) + // Call site format + TargetAsmInfo::getULEB128Size(SizeSites) + // Call-site table length + SizeSites + SizeActions + SizeTypes; + + unsigned TotalSize = sizeof(int8_t) + // LPStart format + sizeof(int8_t) + // TType format + TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset + TypeOffset; + + unsigned SizeAlign = (4 - TotalSize) & 3; + + // Begin the exception table. + Asm->SwitchToDataSection(TAI->getDwarfExceptionSection()); + Asm->EmitAlignment(2, 0, 0, false); + O << "GCC_except_table" << SubprogramCount << ":\n"; + + for (unsigned i = 0; i != SizeAlign; ++i) { + Asm->EmitInt8(0); + Asm->EOL("Padding"); + } + + EmitLabel("exception", SubprogramCount); + + // Emit the header. + Asm->EmitInt8(dwarf::DW_EH_PE_omit); + Asm->EOL("LPStart format (DW_EH_PE_omit)"); + Asm->EmitInt8(dwarf::DW_EH_PE_absptr); + Asm->EOL("TType format (DW_EH_PE_absptr)"); + Asm->EmitULEB128Bytes(TypeOffset); + Asm->EOL("TType base offset"); + Asm->EmitInt8(dwarf::DW_EH_PE_udata4); + Asm->EOL("Call site format (DW_EH_PE_udata4)"); + Asm->EmitULEB128Bytes(SizeSites); + Asm->EOL("Call-site table length"); + + // Emit the landing pad site information. + for (unsigned i = 0; i < CallSites.size(); ++i) { + CallSiteEntry &S = CallSites[i]; + const char *BeginTag; + unsigned BeginNumber; + + if (!S.BeginLabel) { + BeginTag = "eh_func_begin"; + BeginNumber = SubprogramCount; + } else { + BeginTag = "label"; + BeginNumber = S.BeginLabel; + } + + EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount, + true, true); + Asm->EOL("Region start"); + + if (!S.EndLabel) + EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber, + true); + else + EmitDifference("label", S.EndLabel, BeginTag, BeginNumber, true); + + Asm->EOL("Region length"); + + if (!S.PadLabel) + Asm->EmitInt32(0); + else + EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount, + true, true); + + Asm->EOL("Landing pad"); + + Asm->EmitULEB128Bytes(S.Action); + Asm->EOL("Action"); + } + + // Emit the actions. + for (unsigned I = 0, N = Actions.size(); I != N; ++I) { + ActionEntry &Action = Actions[I]; + + Asm->EmitSLEB128Bytes(Action.ValueForTypeID); + Asm->EOL("TypeInfo index"); + Asm->EmitSLEB128Bytes(Action.NextAction); + Asm->EOL("Next action"); + } + + // Emit the type ids. + for (unsigned M = TypeInfos.size(); M; --M) { + GlobalVariable *GV = TypeInfos[M - 1]; + PrintRelDirective(); + + if (GV) { + std::string GLN; + O << Asm->getGlobalLinkName(GV, GLN); + } else { + O << "0"; + } + + Asm->EOL("TypeInfo"); + } + + // Emit the filter typeids. + for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) { + unsigned TypeID = FilterIds[j]; + Asm->EmitULEB128Bytes(TypeID); + Asm->EOL("Filter TypeInfo index"); + } + + Asm->EmitAlignment(2, 0, 0, false); +} + +/// EndModule - Emit all exception information that should come after the +/// content. +void DwarfException::EndModule() { + if (TimePassesIsEnabled) + ExceptionTimer->startTimer(); + + if (shouldEmitMovesModule || shouldEmitTableModule) { + const std::vector<Function *> Personalities = MMI->getPersonalities(); + for (unsigned i = 0; i < Personalities.size(); ++i) + EmitCommonEHFrame(Personalities[i], i); + + for (std::vector<FunctionEHFrameInfo>::iterator I = EHFrames.begin(), + E = EHFrames.end(); I != E; ++I) + EmitEHFrame(*I); + } + + if (TimePassesIsEnabled) + ExceptionTimer->stopTimer(); +} + +/// BeginFunction - Gather pre-function exception information. Assumes being +/// emitted immediately after the function entry point. +void DwarfException::BeginFunction(MachineFunction *MF) { + if (TimePassesIsEnabled) + ExceptionTimer->startTimer(); + + this->MF = MF; + shouldEmitTable = shouldEmitMoves = false; + + if (MMI && TAI->doesSupportExceptionHandling()) { + // Map all labels and get rid of any dead landing pads. + MMI->TidyLandingPads(); + + // If any landing pads survive, we need an EH table. + if (MMI->getLandingPads().size()) + shouldEmitTable = true; + + // See if we need frame move info. + if (!MF->getFunction()->doesNotThrow() || UnwindTablesMandatory) + shouldEmitMoves = true; + + if (shouldEmitMoves || shouldEmitTable) + // Assumes in correct section after the entry point. + EmitLabel("eh_func_begin", ++SubprogramCount); + } + + shouldEmitTableModule |= shouldEmitTable; + shouldEmitMovesModule |= shouldEmitMoves; + + if (TimePassesIsEnabled) + ExceptionTimer->stopTimer(); +} + +/// EndFunction - Gather and emit post-function exception information. +/// +void DwarfException::EndFunction() { + if (TimePassesIsEnabled) + ExceptionTimer->startTimer(); + + if (shouldEmitMoves || shouldEmitTable) { + EmitLabel("eh_func_end", SubprogramCount); + EmitExceptionTable(); + + // Save EH frame information + std::string Name; + EHFrames.push_back( + FunctionEHFrameInfo(getAsm()->getCurrentFunctionEHName(MF, Name), + SubprogramCount, + MMI->getPersonalityIndex(), + MF->getFrameInfo()->hasCalls(), + !MMI->getLandingPads().empty(), + MMI->getFrameMoves(), + MF->getFunction())); + } + + if (TimePassesIsEnabled) + ExceptionTimer->stopTimer(); +} |
