diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/AsmPrinter/DwarfTableException.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/AsmPrinter/DwarfTableException.cpp | 349 |
1 files changed, 0 insertions, 349 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfTableException.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfTableException.cpp deleted file mode 100644 index b50d8bd..0000000 --- a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfTableException.cpp +++ /dev/null @@ -1,349 +0,0 @@ -//===-- CodeGen/AsmPrinter/DwarfTableException.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. -// The implementation emits all the necessary tables "by hands". -// -//===----------------------------------------------------------------------===// - -#include "DwarfException.h" -#include "llvm/Module.h" -#include "llvm/CodeGen/AsmPrinter.h" -#include "llvm/CodeGen/MachineModuleInfo.h" -#include "llvm/CodeGen/MachineFrameInfo.h" -#include "llvm/CodeGen/MachineFunction.h" -#include "llvm/CodeGen/MachineLocation.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/Target/Mangler.h" -#include "llvm/Target/TargetData.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" -#include "llvm/Support/Dwarf.h" -#include "llvm/Support/FormattedStream.h" -#include "llvm/ADT/SmallString.h" -#include "llvm/ADT/StringExtras.h" -#include "llvm/ADT/Twine.h" -using namespace llvm; - -DwarfTableException::DwarfTableException(AsmPrinter *A) - : DwarfException(A), - shouldEmitTable(false), shouldEmitMoves(false), - shouldEmitTableModule(false), shouldEmitMovesModule(false) {} - -DwarfTableException::~DwarfTableException() {} - -/// 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. -void DwarfTableException::EmitCIE(const Function *PersonalityFn, unsigned Index) { - // Size and sign of stack growth. - int stackGrowth = Asm->getTargetData().getPointerSize(); - if (Asm->TM.getFrameLowering()->getStackGrowthDirection() == - TargetFrameLowering::StackGrowsDown) - stackGrowth *= -1; - - const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); - - // Begin eh frame section. - Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection()); - - MCSymbol *EHFrameSym; - if (TLOF.isFunctionEHFrameSymbolPrivate()) - EHFrameSym = Asm->GetTempSymbol("EH_frame", Index); - else - EHFrameSym = Asm->OutContext.GetOrCreateSymbol(Twine("EH_frame") + - Twine(Index)); - Asm->OutStreamer.EmitLabel(EHFrameSym); - - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("section_eh_frame", Index)); - - // Define base labels. - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common", Index)); - - // Define the eh frame length. - Asm->OutStreamer.AddComment("Length of Common Information Entry"); - Asm->EmitLabelDifference(Asm->GetTempSymbol("eh_frame_common_end", Index), - Asm->GetTempSymbol("eh_frame_common_begin", Index), - 4); - - // EH frame header. - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common_begin",Index)); - Asm->OutStreamer.AddComment("CIE Identifier Tag"); - Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/); - Asm->OutStreamer.AddComment("DW_CIE_VERSION"); - Asm->OutStreamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1/*size*/, 0/*addr*/); - - // The personality presence indicates that language specific information will - // show up in the eh frame. Find out how we are supposed to lower the - // personality function reference: - - unsigned LSDAEncoding = TLOF.getLSDAEncoding(); - unsigned FDEEncoding = TLOF.getFDEEncoding(false); - unsigned PerEncoding = TLOF.getPersonalityEncoding(); - - char Augmentation[6] = { 0 }; - unsigned AugmentationSize = 0; - char *APtr = Augmentation + 1; - - if (PersonalityFn) { - // There is a personality function. - *APtr++ = 'P'; - AugmentationSize += 1 + Asm->GetSizeOfEncodedValue(PerEncoding); - } - - if (UsesLSDA[Index]) { - // An LSDA pointer is in the FDE augmentation. - *APtr++ = 'L'; - ++AugmentationSize; - } - - if (FDEEncoding != dwarf::DW_EH_PE_absptr) { - // A non-default pointer encoding for the FDE. - *APtr++ = 'R'; - ++AugmentationSize; - } - - if (APtr != Augmentation + 1) - Augmentation[0] = 'z'; - - Asm->OutStreamer.AddComment("CIE Augmentation"); - Asm->OutStreamer.EmitBytes(StringRef(Augmentation, strlen(Augmentation)+1),0); - - // Round out reader. - Asm->EmitULEB128(1, "CIE Code Alignment Factor"); - Asm->EmitSLEB128(stackGrowth, "CIE Data Alignment Factor"); - Asm->OutStreamer.AddComment("CIE Return Address Column"); - - const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo(); - const TargetFrameLowering *TFI = Asm->TM.getFrameLowering(); - Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true)); - - if (Augmentation[0]) { - Asm->EmitULEB128(AugmentationSize, "Augmentation Size"); - - // If there is a personality, we need to indicate the function's location. - if (PersonalityFn) { - Asm->EmitEncodingByte(PerEncoding, "Personality"); - Asm->OutStreamer.AddComment("Personality"); - Asm->EmitReference(PersonalityFn, PerEncoding); - } - if (UsesLSDA[Index]) - Asm->EmitEncodingByte(LSDAEncoding, "LSDA"); - if (FDEEncoding != dwarf::DW_EH_PE_absptr) - Asm->EmitEncodingByte(FDEEncoding, "FDE"); - } - - // Indicate locations of general callee saved registers in frame. - std::vector<MachineMove> Moves; - TFI->getInitialFrameState(Moves); - Asm->EmitFrameMoves(Moves, 0, 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(Asm->getTargetData().getPointerSize() == 4 ? 2 : 3); - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_common_end", Index)); -} - -/// EmitFDE - Emit the Frame Description Entry (FDE) for the function. -void DwarfTableException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) { - assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() && - "Should not emit 'available externally' functions at all"); - - const Function *TheFunc = EHFrameInfo.function; - const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); - - unsigned LSDAEncoding = TLOF.getLSDAEncoding(); - unsigned FDEEncoding = TLOF.getFDEEncoding(false); - - Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection()); - - // Externally visible entry into the functions eh frame info. If the - // corresponding function is static, this should not be externally visible. - if (!TheFunc->hasLocalLinkage() && TLOF.isFunctionEHSymbolGlobal()) - Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym,MCSA_Global); - - // If corresponding function is weak definition, this should be too. - if (TheFunc->isWeakForLinker() && Asm->MAI->getWeakDefDirective()) - Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, - MCSA_WeakDefinition); - - // If corresponding function is hidden, this should be too. - if (TheFunc->hasHiddenVisibility()) - if (MCSymbolAttr HiddenAttr = Asm->MAI->getHiddenVisibilityAttr()) - Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, - HiddenAttr); - - // 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.adjustsStack && !UnwindTablesMandatory && - (!TheFunc->isWeakForLinker() || - !Asm->MAI->getWeakDefDirective() || - TLOF.getSupportsWeakOmittedEHFrame())) { - Asm->OutStreamer.EmitAssignment(EHFrameInfo.FunctionEHSym, - MCConstantExpr::Create(0, Asm->OutContext)); - // 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 (Asm->MAI->hasNoDeadStrip()) - Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, - MCSA_NoDeadStrip); - } else { - Asm->OutStreamer.EmitLabel(EHFrameInfo.FunctionEHSym); - - // EH frame header. - Asm->OutStreamer.AddComment("Length of Frame Information Entry"); - Asm->EmitLabelDifference( - Asm->GetTempSymbol("eh_frame_end", EHFrameInfo.Number), - Asm->GetTempSymbol("eh_frame_begin", EHFrameInfo.Number), 4); - - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_frame_begin", - EHFrameInfo.Number)); - - Asm->OutStreamer.AddComment("FDE CIE offset"); - Asm->EmitLabelDifference( - Asm->GetTempSymbol("eh_frame_begin", EHFrameInfo.Number), - Asm->GetTempSymbol("eh_frame_common", - EHFrameInfo.PersonalityIndex), 4); - - MCSymbol *EHFuncBeginSym = - Asm->GetTempSymbol("eh_func_begin", EHFrameInfo.Number); - - Asm->OutStreamer.AddComment("FDE initial location"); - Asm->EmitReference(EHFuncBeginSym, FDEEncoding); - - Asm->OutStreamer.AddComment("FDE address range"); - Asm->EmitLabelDifference(Asm->GetTempSymbol("eh_func_end", - EHFrameInfo.Number), - EHFuncBeginSym, - Asm->GetSizeOfEncodedValue(FDEEncoding)); - - // If there is a personality and landing pads then point to the language - // specific data area in the exception table. - if (MMI->getPersonalities()[0] != NULL) { - unsigned Size = Asm->GetSizeOfEncodedValue(LSDAEncoding); - - Asm->EmitULEB128(Size, "Augmentation size"); - Asm->OutStreamer.AddComment("Language Specific Data Area"); - if (EHFrameInfo.hasLandingPads) - Asm->EmitReference(Asm->GetTempSymbol("exception", EHFrameInfo.Number), - LSDAEncoding); - else - Asm->OutStreamer.EmitIntValue(0, Size/*size*/, 0/*addrspace*/); - - } else { - Asm->EmitULEB128(0, "Augmentation size"); - } - - // Indicate locations of function specific callee saved registers in frame. - Asm->EmitFrameMoves(EHFrameInfo.Moves, EHFuncBeginSym, 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(Asm->getTargetData().getPointerSize() == 4 ? 2 : 3); - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("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->isUsedFunction(EHFrameInfo.function)) - if (Asm->MAI->hasNoDeadStrip()) - Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, - MCSA_NoDeadStrip); - } - Asm->OutStreamer.AddBlankLine(); -} - -/// EndModule - Emit all exception information that should come after the -/// content. -void DwarfTableException::EndModule() { - if (!Asm->MAI->isExceptionHandlingDwarf()) - return; - - if (!shouldEmitMovesModule && !shouldEmitTableModule) - return; - - const std::vector<const Function*> &Personalities = MMI->getPersonalities(); - - for (unsigned I = 0, E = Personalities.size(); I < E; ++I) - EmitCIE(Personalities[I], I); - - for (std::vector<FunctionEHFrameInfo>::iterator - I = EHFrames.begin(), E = EHFrames.end(); I != E; ++I) - EmitFDE(*I); -} - -/// BeginFunction - Gather pre-function exception information. Assumes it's -/// being emitted immediately after the function entry point. -void DwarfTableException::BeginFunction(const MachineFunction *MF) { - shouldEmitTable = shouldEmitMoves = false; - - // If any landing pads survive, we need an EH table. - shouldEmitTable = !MMI->getLandingPads().empty(); - - // See if we need frame move info. - shouldEmitMoves = - !Asm->MF->getFunction()->doesNotThrow() || UnwindTablesMandatory; - - if (shouldEmitMoves || shouldEmitTable) - // Assumes in correct section after the entry point. - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin", - Asm->getFunctionNumber())); - - shouldEmitTableModule |= shouldEmitTable; - shouldEmitMovesModule |= shouldEmitMoves; -} - -/// EndFunction - Gather and emit post-function exception information. -/// -void DwarfTableException::EndFunction() { - if (!shouldEmitMoves && !shouldEmitTable) return; - - Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end", - Asm->getFunctionNumber())); - - // Record if this personality index uses a landing pad. - bool HasLandingPad = !MMI->getLandingPads().empty(); - UsesLSDA[MMI->getPersonalityIndex()] |= HasLandingPad; - - // Map all labels and get rid of any dead landing pads. - MMI->TidyLandingPads(); - - if (HasLandingPad) - EmitExceptionTable(); - - const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); - MCSymbol *FunctionEHSym = - Asm->GetSymbolWithGlobalValueBase(Asm->MF->getFunction(), ".eh", - TLOF.isFunctionEHFrameSymbolPrivate()); - - // Save EH frame information - EHFrames. - push_back(FunctionEHFrameInfo(FunctionEHSym, - Asm->getFunctionNumber(), - MMI->getPersonalityIndex(), - Asm->MF->getFrameInfo()->adjustsStack(), - !MMI->getLandingPads().empty(), - MMI->getFrameMoves(), - Asm->MF->getFunction())); -} |
