DwarfException.cpp revision 1f8075d7d232dd0c7b0caa81ed3ce426a13f5a66
1eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling//===-- CodeGen/AsmPrinter/DwarfException.cpp - Dwarf Exception Impl ------===// 2eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// 3eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// The LLVM Compiler Infrastructure 4eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// 5eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// This file is distributed under the University of Illinois Open Source 6eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// License. See LICENSE.TXT for details. 7eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// 8eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling//===----------------------------------------------------------------------===// 9eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// 1028275fdf02885587156da5cb20388b22d5b96557Bill Wendling// This file contains support for writing DWARF exception info into asm files. 11eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling// 12eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling//===----------------------------------------------------------------------===// 13eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 14eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "DwarfException.h" 15eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/Module.h" 16eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/CodeGen/MachineModuleInfo.h" 17eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/CodeGen/MachineFrameInfo.h" 18fc4da0cea8a0f6c9c1483b92c2dffda217c0ba24David Greene#include "llvm/CodeGen/MachineFunction.h" 19eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/CodeGen/MachineLocation.h" 208c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner#include "llvm/MC/MCAsmInfo.h" 218c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner#include "llvm/MC/MCContext.h" 228c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner#include "llvm/MC/MCExpr.h" 2343e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling#include "llvm/MC/MCSection.h" 246c2f9e14fdf14d8c1c687c6bd9918183fa7f8a7fChris Lattner#include "llvm/MC/MCStreamer.h" 257a2ba94d03b43f41b54872dacd7b2250dde4c7bdChris Lattner#include "llvm/MC/MCSymbol.h" 2645111d160cf0910030eeb6a949c69273502e5ad5Chris Lattner#include "llvm/Target/Mangler.h" 27eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/Target/TargetData.h" 28eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/Target/TargetFrameInfo.h" 29d5bbb07ec806e6fa1e804afd7073987fdacc83e4Chris Lattner#include "llvm/Target/TargetLoweringObjectFile.h" 30eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/Target/TargetOptions.h" 31d5bbb07ec806e6fa1e804afd7073987fdacc83e4Chris Lattner#include "llvm/Target/TargetRegisterInfo.h" 326c2f9e14fdf14d8c1c687c6bd9918183fa7f8a7fChris Lattner#include "llvm/Support/Dwarf.h" 330ad9c911f5b7737ae199d703279984138553de9dChris Lattner#include "llvm/Support/FormattedStream.h" 346c2f9e14fdf14d8c1c687c6bd9918183fa7f8a7fChris Lattner#include "llvm/Support/Timer.h" 35c40d9f9bae70c83947bf8fa5f9ee97adbf1bb0c0Jim Grosbach#include "llvm/ADT/SmallString.h" 36eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling#include "llvm/ADT/StringExtras.h" 371f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling#include "llvm/ADT/Twine.h" 38eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendlingusing namespace llvm; 39eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 40bc0d23afae781c45f92865c1c27bed0ce51fe545Bill WendlingDwarfException::DwarfException(raw_ostream &OS, AsmPrinter *A, 41af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner const MCAsmInfo *T) 42066c9acca354e88c19ce740a7ff0e5910362aa7bChris Lattner : DwarfPrinter(OS, A, T, "eh"), shouldEmitTable(false),shouldEmitMoves(false), 43bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling shouldEmitTableModule(false), shouldEmitMovesModule(false), 44bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling ExceptionTimer(0) { 45dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher if (TimePassesIsEnabled) 460b86a6f049e4d839bd770241571628d10c980887Chris Lattner ExceptionTimer = new Timer("DWARF Exception Writer"); 47bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling} 48bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling 49bc0d23afae781c45f92865c1c27bed0ce51fe545Bill WendlingDwarfException::~DwarfException() { 50bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling delete ExceptionTimer; 51bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling} 52bc0d23afae781c45f92865c1c27bed0ce51fe545Bill Wendling 53bb3e29932d14cc012149a1ab452b88e6f6f5bb49Bill Wendling/// SizeOfEncodedValue - Return the size of the encoding in bytes. 5452783c63a13d384582997684384553e6545852d3Bill Wendlingunsigned DwarfException::SizeOfEncodedValue(unsigned Encoding) { 5552783c63a13d384582997684384553e6545852d3Bill Wendling if (Encoding == dwarf::DW_EH_PE_omit) 5652783c63a13d384582997684384553e6545852d3Bill Wendling return 0; 5752783c63a13d384582997684384553e6545852d3Bill Wendling 5852783c63a13d384582997684384553e6545852d3Bill Wendling switch (Encoding & 0x07) { 5952783c63a13d384582997684384553e6545852d3Bill Wendling case dwarf::DW_EH_PE_absptr: 6052783c63a13d384582997684384553e6545852d3Bill Wendling return TD->getPointerSize(); 6152783c63a13d384582997684384553e6545852d3Bill Wendling case dwarf::DW_EH_PE_udata2: 6252783c63a13d384582997684384553e6545852d3Bill Wendling return 2; 6352783c63a13d384582997684384553e6545852d3Bill Wendling case dwarf::DW_EH_PE_udata4: 6452783c63a13d384582997684384553e6545852d3Bill Wendling return 4; 6552783c63a13d384582997684384553e6545852d3Bill Wendling case dwarf::DW_EH_PE_udata8: 6652783c63a13d384582997684384553e6545852d3Bill Wendling return 8; 6752783c63a13d384582997684384553e6545852d3Bill Wendling } 6852783c63a13d384582997684384553e6545852d3Bill Wendling 6928275fdf02885587156da5cb20388b22d5b96557Bill Wendling assert(0 && "Invalid encoded value."); 7052783c63a13d384582997684384553e6545852d3Bill Wendling return 0; 7152783c63a13d384582997684384553e6545852d3Bill Wendling} 7252783c63a13d384582997684384553e6545852d3Bill Wendling 737378b1bd00033d8be64d388d60a562027cbf953aBill Wendling/// CreateLabelDiff - Emit a label and subtract it from the expression we 747378b1bd00033d8be64d388d60a562027cbf953aBill Wendling/// already have. This is equivalent to emitting "foo - .", but we have to emit 757378b1bd00033d8be64d388d60a562027cbf953aBill Wendling/// the label for "." directly. 767378b1bd00033d8be64d388d60a562027cbf953aBill Wendlingconst MCExpr *DwarfException::CreateLabelDiff(const MCExpr *ExprRef, 777378b1bd00033d8be64d388d60a562027cbf953aBill Wendling const char *LabelName, 787378b1bd00033d8be64d388d60a562027cbf953aBill Wendling unsigned Index) { 797378b1bd00033d8be64d388d60a562027cbf953aBill Wendling SmallString<64> Name; 807378b1bd00033d8be64d388d60a562027cbf953aBill Wendling raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() 817378b1bd00033d8be64d388d60a562027cbf953aBill Wendling << LabelName << Asm->getFunctionNumber() 827378b1bd00033d8be64d388d60a562027cbf953aBill Wendling << "_" << Index; 837378b1bd00033d8be64d388d60a562027cbf953aBill Wendling MCSymbol *DotSym = Asm->OutContext.GetOrCreateSymbol(Name.str()); 847378b1bd00033d8be64d388d60a562027cbf953aBill Wendling Asm->OutStreamer.EmitLabel(DotSym); 857378b1bd00033d8be64d388d60a562027cbf953aBill Wendling 867378b1bd00033d8be64d388d60a562027cbf953aBill Wendling return MCBinaryExpr::CreateSub(ExprRef, 877378b1bd00033d8be64d388d60a562027cbf953aBill Wendling MCSymbolRefExpr::Create(DotSym, 887378b1bd00033d8be64d388d60a562027cbf953aBill Wendling Asm->OutContext), 897378b1bd00033d8be64d388d60a562027cbf953aBill Wendling Asm->OutContext); 907378b1bd00033d8be64d388d60a562027cbf953aBill Wendling} 917378b1bd00033d8be64d388d60a562027cbf953aBill Wendling 927ccda0f2aadb601ce48f05c12cc153f3fcc554e6Bill Wendling/// EmitCIE - Emit a Common Information Entry (CIE). This holds information that 937ccda0f2aadb601ce48f05c12cc153f3fcc554e6Bill Wendling/// is shared among many Frame Description Entries. There is at least one CIE 947ccda0f2aadb601ce48f05c12cc153f3fcc554e6Bill Wendling/// in every non-empty .debug_frame section. 958c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattnervoid DwarfException::EmitCIE(const Function *PersonalityFn, unsigned Index) { 96eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Size and sign of stack growth. 97eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling int stackGrowth = 98eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling Asm->TM.getFrameInfo()->getStackGrowthDirection() == 99eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling TargetFrameInfo::StackGrowsUp ? 100eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling TD->getPointerSize() : -TD->getPointerSize(); 101eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 1028c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering(); 1038c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner 104eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Begin eh frame section. 1058c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner Asm->OutStreamer.SwitchSection(TLOF.getEHFrameSection()); 106eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 10733adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner if (MAI->is_EHSymbolPrivate()) 10833adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner O << MAI->getPrivateGlobalPrefix(); 109eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling O << "EH_frame" << Index << ":\n"; 1108c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner 111eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitLabel("section_eh_frame", Index); 112eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 113eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Define base labels. 114eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitLabel("eh_frame_common", Index); 115eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 116eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Define the eh frame length. 117eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitDifference("eh_frame_common_end", Index, 118eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling "eh_frame_common_begin", Index, true); 119faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Length of Common Information Entry"); 120eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 121eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // EH frame header. 122eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitLabel("eh_frame_common_begin", Index); 123066c9acca354e88c19ce740a7ff0e5910362aa7bChris Lattner if (Asm->VerboseAsm) Asm->OutStreamer.AddComment("CIE Identifier Tag"); 124bcb83e5b6c8e074e73986cb641801ecbedd6e4edChris Lattner Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/); 125066c9acca354e88c19ce740a7ff0e5910362aa7bChris Lattner if (Asm->VerboseAsm) Asm->OutStreamer.AddComment("DW_CIE_VERSION"); 126066c9acca354e88c19ce740a7ff0e5910362aa7bChris Lattner Asm->OutStreamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1/*size*/, 0/*addr*/); 127eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 128eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // The personality presence indicates that language specific information will 1298c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner // show up in the eh frame. Find out how we are supposed to lower the 1308c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner // personality function reference: 1318c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner const MCExpr *PersonalityRef = 0; 1328c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner bool IsPersonalityIndirect = false, IsPersonalityPCRel = false; 1338c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner if (PersonalityFn) { 1348c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner // FIXME: HANDLE STATIC CODEGEN MODEL HERE. 1358c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner 1368c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner // In non-static mode, ask the object file how to represent this reference. 1378c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner PersonalityRef = 1388c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner TLOF.getSymbolForDwarfGlobalReference(PersonalityFn, Asm->Mang, 1398609c7c931c0213d6d29f665df2110cf3c709e4cChris Lattner Asm->MMI, 1408c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner IsPersonalityIndirect, 1418c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner IsPersonalityPCRel); 1428c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner } 1438c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner 14452783c63a13d384582997684384553e6545852d3Bill Wendling unsigned PerEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 1458c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner if (IsPersonalityIndirect) 14652783c63a13d384582997684384553e6545852d3Bill Wendling PerEncoding |= dwarf::DW_EH_PE_indirect; 14752783c63a13d384582997684384553e6545852d3Bill Wendling unsigned LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 14852783c63a13d384582997684384553e6545852d3Bill Wendling unsigned FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 14952783c63a13d384582997684384553e6545852d3Bill Wendling 1504cf202ba066a1310d8968c8d069787254934e59bChris Lattner char Augmentation[6] = { 0 }; 15152783c63a13d384582997684384553e6545852d3Bill Wendling unsigned AugmentationSize = 0; 15252783c63a13d384582997684384553e6545852d3Bill Wendling char *APtr = Augmentation + 1; 15352783c63a13d384582997684384553e6545852d3Bill Wendling 1548c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner if (PersonalityRef) { 15552783c63a13d384582997684384553e6545852d3Bill Wendling // There is a personality function. 15652783c63a13d384582997684384553e6545852d3Bill Wendling *APtr++ = 'P'; 15752783c63a13d384582997684384553e6545852d3Bill Wendling AugmentationSize += 1 + SizeOfEncodedValue(PerEncoding); 15852783c63a13d384582997684384553e6545852d3Bill Wendling } 15952783c63a13d384582997684384553e6545852d3Bill Wendling 16052783c63a13d384582997684384553e6545852d3Bill Wendling if (UsesLSDA[Index]) { 16152783c63a13d384582997684384553e6545852d3Bill Wendling // An LSDA pointer is in the FDE augmentation. 16252783c63a13d384582997684384553e6545852d3Bill Wendling *APtr++ = 'L'; 16352783c63a13d384582997684384553e6545852d3Bill Wendling ++AugmentationSize; 16452783c63a13d384582997684384553e6545852d3Bill Wendling } 16552783c63a13d384582997684384553e6545852d3Bill Wendling 16652783c63a13d384582997684384553e6545852d3Bill Wendling if (FDEEncoding != dwarf::DW_EH_PE_absptr) { 16752783c63a13d384582997684384553e6545852d3Bill Wendling // A non-default pointer encoding for the FDE. 16852783c63a13d384582997684384553e6545852d3Bill Wendling *APtr++ = 'R'; 16952783c63a13d384582997684384553e6545852d3Bill Wendling ++AugmentationSize; 17052783c63a13d384582997684384553e6545852d3Bill Wendling } 17152783c63a13d384582997684384553e6545852d3Bill Wendling 17252783c63a13d384582997684384553e6545852d3Bill Wendling if (APtr != Augmentation + 1) 17352783c63a13d384582997684384553e6545852d3Bill Wendling Augmentation[0] = 'z'; 17452783c63a13d384582997684384553e6545852d3Bill Wendling 1754cf202ba066a1310d8968c8d069787254934e59bChris Lattner Asm->OutStreamer.EmitBytes(StringRef(Augmentation, strlen(Augmentation)+1),0); 176faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("CIE Augmentation"); 177eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 178eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Round out reader. 179894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(1, "CIE Code Alignment Factor"); 180bb9078a6b26f38594cde6fd0dcd17eca25ef0319Chris Lattner EmitSLEB128(stackGrowth, "CIE Data Alignment Factor"); 181eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true)); 182faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("CIE Return Address Column"); 183eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 184894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(AugmentationSize, "Augmentation Size"); 185f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(PerEncoding, "Personality"); 18652783c63a13d384582997684384553e6545852d3Bill Wendling 1874bda11fbdafc1d4fa97b7539bdf5a0f62ecfc280Bill Wendling // If there is a personality, we need to indicate the function's location. 1888c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner if (PersonalityRef) { 1897378b1bd00033d8be64d388d60a562027cbf953aBill Wendling if (!IsPersonalityPCRel) 1907378b1bd00033d8be64d388d60a562027cbf953aBill Wendling PersonalityRef = CreateLabelDiff(PersonalityRef, "personalityref_addr", 1917378b1bd00033d8be64d388d60a562027cbf953aBill Wendling Index); 1927378b1bd00033d8be64d388d60a562027cbf953aBill Wendling 1938cb9a3b13f3226b7e741768b69d26ecd6b5231f1Chris Lattner O << MAI->getData32bitsDirective() << *PersonalityRef; 194faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Personality"); 195eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 196f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(LSDAEncoding, "LSDA"); 197f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(FDEEncoding, "FDE"); 198eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 199eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 200eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Indicate locations of general callee saved registers in frame. 201eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling std::vector<MachineMove> Moves; 202eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling RI->getInitialFrameState(Moves); 203eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitFrameMoves(NULL, 0, Moves, true); 204eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 205eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // On Darwin the linker honors the alignment of eh_frame, which means it must 206eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // be 8-byte on 64-bit targets to match what gcc does. Otherwise you get 207eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // holes which confuse readers of eh_frame. 2088c6ed05157e9c97ff8f3ccb211dd797e53228da1Chris Lattner Asm->EmitAlignment(TD->getPointerSize() == 4 ? 2 : 3, 0, 0, false); 209eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitLabel("eh_frame_common_end", Index); 2100ad9c911f5b7737ae199d703279984138553de9dChris Lattner Asm->O << '\n'; 211eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 212eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 2137ccda0f2aadb601ce48f05c12cc153f3fcc554e6Bill Wendling/// EmitFDE - Emit the Frame Description Entry (FDE) for the function. 2147ccda0f2aadb601ce48f05c12cc153f3fcc554e6Bill Wendlingvoid DwarfException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) { 215dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() && 216eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling "Should not emit 'available externally' functions at all"); 217eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 2183e0f60be46cb5363d4375f26a5e27d1dcd9867fbChris Lattner const Function *TheFunc = EHFrameInfo.function; 219dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher 2206c2f9e14fdf14d8c1c687c6bd9918183fa7f8a7fChris Lattner Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering().getEHFrameSection()); 221dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher 222eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Externally visible entry into the functions eh frame info. If the 223eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // corresponding function is static, this should not be externally visible. 2243e0f60be46cb5363d4375f26a5e27d1dcd9867fbChris Lattner if (!TheFunc->hasLocalLinkage()) 22510b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner if (const char *GlobalEHDirective = MAI->getGlobalEHDirective()) 22610b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner O << GlobalEHDirective << *EHFrameInfo.FunctionEHSym << '\n'; 227eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 228eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // If corresponding function is weak definition, this should be too. 22910b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner if (TheFunc->isWeakForLinker() && MAI->getWeakDefDirective()) 23010b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner O << MAI->getWeakDefDirective() << *EHFrameInfo.FunctionEHSym << '\n'; 231ee161a68240dfe7e28fdc45d5595380a3ec3b9c8Bill Wendling 232ee161a68240dfe7e28fdc45d5595380a3ec3b9c8Bill Wendling // If corresponding function is hidden, this should be too. 233ee161a68240dfe7e28fdc45d5595380a3ec3b9c8Bill Wendling if (TheFunc->hasHiddenVisibility()) 234152a29bfa6fa505182658d046bc75626e10d67c3Chris Lattner if (MCSymbolAttr HiddenAttr = MAI->getHiddenVisibilityAttr()) 235152a29bfa6fa505182658d046bc75626e10d67c3Chris Lattner Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, 236152a29bfa6fa505182658d046bc75626e10d67c3Chris Lattner HiddenAttr); 237eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 238eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // If there are no calls then you can't unwind. This may mean we can omit the 239eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // EH Frame, but some environments do not handle weak absolute symbols. If 240eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // UnwindTablesMandatory is set we cannot do this optimization; the unwind 241eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // info is to be available for non-EH uses. 2423e0f60be46cb5363d4375f26a5e27d1dcd9867fbChris Lattner if (!EHFrameInfo.hasCalls && !UnwindTablesMandatory && 2433e0f60be46cb5363d4375f26a5e27d1dcd9867fbChris Lattner (!TheFunc->isWeakForLinker() || 24433adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner !MAI->getWeakDefDirective() || 24533adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner MAI->getSupportsWeakOmittedEHFrame())) { 24610b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner O << *EHFrameInfo.FunctionEHSym << " = 0\n"; 247eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // This name has no connection to the function, so it might get 248eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // dead-stripped when the function is not, erroneously. Prohibit 249eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // dead-stripping unconditionally. 2503a9be0ee36fe2143f514d28315f3dc1bda132b2eChris Lattner if (MAI->hasNoDeadStrip()) 2513a9be0ee36fe2143f514d28315f3dc1bda132b2eChris Lattner Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, 252a5ad93a10a5435f21090b09edb6b3a7e44967648Chris Lattner MCSA_NoDeadStrip); 253eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } else { 25410b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner O << *EHFrameInfo.FunctionEHSym << ":\n"; 255eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 256eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // EH frame header. 257eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitDifference("eh_frame_end", EHFrameInfo.Number, 258eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling "eh_frame_begin", EHFrameInfo.Number, true); 259faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Length of Frame Information Entry"); 260eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 261eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitLabel("eh_frame_begin", EHFrameInfo.Number); 262eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 263a4ff5e48fc6a4718d3a2af8654cfc06a17310aedChris Lattner EmitSectionOffset("eh_frame_begin", "eh_frame_common", 264a4ff5e48fc6a4718d3a2af8654cfc06a17310aedChris Lattner EHFrameInfo.Number, EHFrameInfo.PersonalityIndex, 265a4ff5e48fc6a4718d3a2af8654cfc06a17310aedChris Lattner true, true, false); 266eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 267faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("FDE CIE offset"); 268eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 269c69d74a5d41a6c5e92f9d947f2fa181f48626ca5Duncan Sands EmitReference("eh_func_begin", EHFrameInfo.Number, true, true); 270faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("FDE initial location"); 271eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitDifference("eh_func_end", EHFrameInfo.Number, 272c69d74a5d41a6c5e92f9d947f2fa181f48626ca5Duncan Sands "eh_func_begin", EHFrameInfo.Number, true); 273faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("FDE address range"); 274eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 275eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // If there is a personality and landing pads then point to the language 276eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // specific data area in the exception table. 277d44fff7849034fc17d6a0e9f9926542865bb7881Eric Christopher if (MMI->getPersonalities()[0] != NULL) { 278c69d74a5d41a6c5e92f9d947f2fa181f48626ca5Duncan Sands 279a8c18890da312e810c687b78658dcd4c989b9776Bill Wendling if (Asm->TM.getLSDAEncoding() != DwarfLSDAEncoding::EightByte) { 280894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(4, "Augmentation size"); 281eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 282d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling if (EHFrameInfo.hasLandingPads) 283d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling EmitReference("exception", EHFrameInfo.Number, true, true); 284aeb79aea8f4761f1c46731ac6bd58cbccdcfa097Bill Wendling else 285bcb83e5b6c8e074e73986cb641801ecbedd6e4edChris Lattner Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/); 286d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling } else { 287894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(TD->getPointerSize(), "Augmentation size"); 288d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling 289d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling if (EHFrameInfo.hasLandingPads) { 290d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling EmitReference("exception", EHFrameInfo.Number, true, false); 291d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling } else { 292bcb83e5b6c8e074e73986cb641801ecbedd6e4edChris Lattner Asm->OutStreamer.EmitIntValue(0, TD->getPointerSize(), 293bcb83e5b6c8e074e73986cb641801ecbedd6e4edChris Lattner 0/*addrspace*/); 294d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling } 295aeb79aea8f4761f1c46731ac6bd58cbccdcfa097Bill Wendling } 296d58e9cb42d7f5cf83c9b982df7e2c822b2e285e9Bill Wendling 297faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Language Specific Data Area"); 298eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } else { 299894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(0, "Augmentation size"); 300eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 301eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 302eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Indicate locations of function specific callee saved registers in frame. 303dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher EmitFrameMoves("eh_func_begin", EHFrameInfo.Number, EHFrameInfo.Moves, 304eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling true); 305eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 306eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // On Darwin the linker honors the alignment of eh_frame, which means it 307eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // must be 8-byte on 64-bit targets to match what gcc does. Otherwise you 308eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // get holes which confuse readers of eh_frame. 309eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3, 310eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 0, 0, false); 311eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling EmitLabel("eh_frame_end", EHFrameInfo.Number); 312eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 313eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // If the function is marked used, this table should be also. We cannot 314eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // make the mark unconditional in this case, since retaining the table also 315eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // retains the function in this case, and there is code around that depends 316eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // on unused functions (calling undefined externals) being dead-stripped to 317eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // link correctly. Yes, there really is. 318401e10c4fbfcdcfade5065093e2ca97f69a1d144Chris Lattner if (MMI->isUsedFunction(EHFrameInfo.function)) 3193a9be0ee36fe2143f514d28315f3dc1bda132b2eChris Lattner if (MAI->hasNoDeadStrip()) 3203a9be0ee36fe2143f514d28315f3dc1bda132b2eChris Lattner Asm->OutStreamer.EmitSymbolAttribute(EHFrameInfo.FunctionEHSym, 321a5ad93a10a5435f21090b09edb6b3a7e44967648Chris Lattner MCSA_NoDeadStrip); 322eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 3230ad9c911f5b7737ae199d703279984138553de9dChris Lattner Asm->O << '\n'; 324eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 325eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 326eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling/// SharedTypeIds - How many leading type ids two landing pads have in common. 327eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendlingunsigned DwarfException::SharedTypeIds(const LandingPadInfo *L, 328eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling const LandingPadInfo *R) { 329eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds; 330eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned LSize = LIds.size(), RSize = RIds.size(); 331eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned MinSize = LSize < RSize ? LSize : RSize; 332eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned Count = 0; 333eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 334eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling for (; Count != MinSize; ++Count) 335eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (LIds[Count] != RIds[Count]) 336eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling return Count; 337eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 338eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling return Count; 339eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 340eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 341eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling/// PadLT - Order landing pads lexicographically by type id. 342eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendlingbool DwarfException::PadLT(const LandingPadInfo *L, const LandingPadInfo *R) { 343eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds; 344eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned LSize = LIds.size(), RSize = RIds.size(); 345eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned MinSize = LSize < RSize ? LSize : RSize; 346eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 347eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling for (unsigned i = 0; i != MinSize; ++i) 348eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (LIds[i] != RIds[i]) 349eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling return LIds[i] < RIds[i]; 350eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 351eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling return LSize < RSize; 352eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 353eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 354d4609622ade8d0ebaf57fd70700c2fedf0b3d165Bill Wendling/// ComputeActionsTable - Compute the actions table and gather the first action 355d4609622ade8d0ebaf57fd70700c2fedf0b3d165Bill Wendling/// index for each landing pad site. 356ade025c65c12503aba161a4fa399fd97414abaffBill Wendlingunsigned DwarfException:: 357ade025c65c12503aba161a4fa399fd97414abaffBill WendlingComputeActionsTable(const SmallVectorImpl<const LandingPadInfo*> &LandingPads, 358ade025c65c12503aba161a4fa399fd97414abaffBill Wendling SmallVectorImpl<ActionEntry> &Actions, 359ade025c65c12503aba161a4fa399fd97414abaffBill Wendling SmallVectorImpl<unsigned> &FirstActions) { 360a583c55864e83e470333b7be878280b10e175a6eBill Wendling 361a583c55864e83e470333b7be878280b10e175a6eBill Wendling // The action table follows the call-site table in the LSDA. The individual 362a583c55864e83e470333b7be878280b10e175a6eBill Wendling // records are of two types: 363a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 364a583c55864e83e470333b7be878280b10e175a6eBill Wendling // * Catch clause 365a583c55864e83e470333b7be878280b10e175a6eBill Wendling // * Exception specification 366a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 367a583c55864e83e470333b7be878280b10e175a6eBill Wendling // The two record kinds have the same format, with only small differences. 368a583c55864e83e470333b7be878280b10e175a6eBill Wendling // They are distinguished by the "switch value" field: Catch clauses 369a583c55864e83e470333b7be878280b10e175a6eBill Wendling // (TypeInfos) have strictly positive switch values, and exception 370a583c55864e83e470333b7be878280b10e175a6eBill Wendling // specifications (FilterIds) have strictly negative switch values. Value 0 371a583c55864e83e470333b7be878280b10e175a6eBill Wendling // indicates a catch-all clause. 372a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 3735e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // Negative type IDs index into FilterIds. Positive type IDs index into 3745e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // TypeInfos. The value written for a positive type ID is just the type ID 3755e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // itself. For a negative type ID, however, the value written is the 376eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // (negative) byte offset of the corresponding FilterIds entry. The byte 3775e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // offset is usually equal to the type ID (because the FilterIds entries are 3785e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // written using a variable width encoding, which outputs one byte per entry 3795e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // as long as the value written is not too large) but can differ. This kind 3805e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling // of complication does not occur for positive type IDs because type infos are 381eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // output using a fixed width encoding. FilterOffsets[i] holds the byte 382eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // offset corresponding to FilterIds[i]. 383409914b773ffd53d53d214394d5636a76f673186Bill Wendling 384409914b773ffd53d53d214394d5636a76f673186Bill Wendling const std::vector<unsigned> &FilterIds = MMI->getFilterIds(); 385eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling SmallVector<int, 16> FilterOffsets; 386eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling FilterOffsets.reserve(FilterIds.size()); 387eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling int Offset = -1; 388409914b773ffd53d53d214394d5636a76f673186Bill Wendling 389409914b773ffd53d53d214394d5636a76f673186Bill Wendling for (std::vector<unsigned>::const_iterator 390409914b773ffd53d53d214394d5636a76f673186Bill Wendling I = FilterIds.begin(), E = FilterIds.end(); I != E; ++I) { 391eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling FilterOffsets.push_back(Offset); 392af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner Offset -= MCAsmInfo::getULEB128Size(*I); 393eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 394eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 395eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling FirstActions.reserve(LandingPads.size()); 396eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 397eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling int FirstAction = 0; 398eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned SizeActions = 0; 3995e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling const LandingPadInfo *PrevLPI = 0; 400409914b773ffd53d53d214394d5636a76f673186Bill Wendling 4015cff487665097d971067cbede1598e249f673182Bill Wendling for (SmallVectorImpl<const LandingPadInfo *>::const_iterator 4025e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling I = LandingPads.begin(), E = LandingPads.end(); I != E; ++I) { 4035e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling const LandingPadInfo *LPI = *I; 4045e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling const std::vector<int> &TypeIds = LPI->TypeIds; 4055e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling const unsigned NumShared = PrevLPI ? SharedTypeIds(LPI, PrevLPI) : 0; 406eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned SizeSiteActions = 0; 407eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 408eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (NumShared < TypeIds.size()) { 409eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned SizeAction = 0; 410eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ActionEntry *PrevAction = 0; 411eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 412eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (NumShared) { 4135e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling const unsigned SizePrevIds = PrevLPI->TypeIds.size(); 414eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling assert(Actions.size()); 415eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling PrevAction = &Actions.back(); 416af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner SizeAction = MCAsmInfo::getSLEB128Size(PrevAction->NextAction) + 417af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner MCAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID); 418eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 419eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling for (unsigned j = NumShared; j != SizePrevIds; ++j) { 420eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling SizeAction -= 421af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner MCAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID); 422eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling SizeAction += -PrevAction->NextAction; 423eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling PrevAction = PrevAction->Previous; 424eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 425eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 426eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 427eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Compute the actions. 4285e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling for (unsigned J = NumShared, M = TypeIds.size(); J != M; ++J) { 4295e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling int TypeID = TypeIds[J]; 4305e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling assert(-1 - TypeID < (int)FilterOffsets.size() && "Unknown filter id!"); 431eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID; 432af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner unsigned SizeTypeID = MCAsmInfo::getSLEB128Size(ValueForTypeID); 433eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 434eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0; 435af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner SizeAction = SizeTypeID + MCAsmInfo::getSLEB128Size(NextAction); 436eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling SizeSiteActions += SizeAction; 437eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 438a583c55864e83e470333b7be878280b10e175a6eBill Wendling ActionEntry Action = { ValueForTypeID, NextAction, PrevAction }; 439eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling Actions.push_back(Action); 440eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling PrevAction = &Actions.back(); 441eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 442eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 443eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Record the first action of the landing pad site. 444eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling FirstAction = SizeActions + SizeSiteActions - SizeAction + 1; 445eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } // else identical - re-use previous FirstAction 446eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 447a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Information used when created the call-site table. The action record 448a583c55864e83e470333b7be878280b10e175a6eBill Wendling // field of the call site record is the offset of the first associated 449a583c55864e83e470333b7be878280b10e175a6eBill Wendling // action record, relative to the start of the actions table. This value is 450a583c55864e83e470333b7be878280b10e175a6eBill Wendling // biased by 1 (1 in dicating the start of the actions table), and 0 451a583c55864e83e470333b7be878280b10e175a6eBill Wendling // indicates that there are no actions. 452eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling FirstActions.push_back(FirstAction); 453eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 454eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Compute this sites contribution to size. 455eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling SizeActions += SizeSiteActions; 4565e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling 4575e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling PrevLPI = LPI; 458eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 459eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 4605e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling return SizeActions; 4615e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling} 4625e953ddfa3abdd684c8a43f9c9c144f584ec7d6fBill Wendling 463ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling/// CallToNoUnwindFunction - Return `true' if this is a call to a function 464ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling/// marked `nounwind'. Return `false' otherwise. 465ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendlingbool DwarfException::CallToNoUnwindFunction(const MachineInstr *MI) { 466ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling assert(MI->getDesc().isCall() && "This should be a call instruction!"); 467ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling 468ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling bool MarkedNoUnwind = false; 469ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling bool SawFunc = false; 470ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling 471ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling for (unsigned I = 0, E = MI->getNumOperands(); I != E; ++I) { 472ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling const MachineOperand &MO = MI->getOperand(I); 473ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling 474ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling if (MO.isGlobal()) { 475ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling if (Function *F = dyn_cast<Function>(MO.getGlobal())) { 476ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling if (SawFunc) { 477ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling // Be conservative. If we have more than one function operand for this 478ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling // call, then we can't make the assumption that it's the callee and 479ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling // not a parameter to the call. 480ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling // 481ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling // FIXME: Determine if there's a way to say that `F' is the callee or 482ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling // parameter. 483ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling MarkedNoUnwind = false; 484ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling break; 485ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling } 486ecc260e403d09ba04ed87d2d04226ac851c68e5aBill Wendling 487ecc260e403d09ba04ed87d2d04226ac851c68e5aBill Wendling MarkedNoUnwind = F->doesNotThrow(); 488ecc260e403d09ba04ed87d2d04226ac851c68e5aBill Wendling SawFunc = true; 489ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling } 490ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling } 491ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling } 492ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling 493ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling return MarkedNoUnwind; 494ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling} 495ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling 496ade025c65c12503aba161a4fa399fd97414abaffBill Wendling/// ComputeCallSiteTable - Compute the call-site table. The entry for an invoke 497a583c55864e83e470333b7be878280b10e175a6eBill Wendling/// has a try-range containing the call, a non-zero landing pad, and an 498ade025c65c12503aba161a4fa399fd97414abaffBill Wendling/// appropriate action. The entry for an ordinary call has a try-range 499ade025c65c12503aba161a4fa399fd97414abaffBill Wendling/// containing the call and zero for the landing pad and the action. Calls 500ade025c65c12503aba161a4fa399fd97414abaffBill Wendling/// marked 'nounwind' have no entry and must not be contained in the try-range 501ade025c65c12503aba161a4fa399fd97414abaffBill Wendling/// of any entry - they form gaps in the table. Entries must be ordered by 502ade025c65c12503aba161a4fa399fd97414abaffBill Wendling/// try-range address. 503ade025c65c12503aba161a4fa399fd97414abaffBill Wendlingvoid DwarfException:: 504ade025c65c12503aba161a4fa399fd97414abaffBill WendlingComputeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites, 505ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const RangeMapType &PadMap, 506ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const SmallVectorImpl<const LandingPadInfo *> &LandingPads, 507ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const SmallVectorImpl<unsigned> &FirstActions) { 508eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // The end label of the previous invoke or nounwind try-range. 509eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned LastLabel = 0; 510eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 511eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Whether there is a potentially throwing instruction (currently this means 512eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // an ordinary call) between the end of the previous try-range and now. 513eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling bool SawPotentiallyThrowing = false; 514eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 5155cff487665097d971067cbede1598e249f673182Bill Wendling // Whether the last CallSite entry was for an invoke. 516eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling bool PreviousIsInvoke = false; 517eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 518eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Visit all instructions in order of address. 519eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 520eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling I != E; ++I) { 521eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end(); 522eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling MI != E; ++MI) { 523eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (!MI->isLabel()) { 524ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling if (MI->getDesc().isCall()) 525ed060dcb5c7e9cb2fd11ff3b0b98203fb53063e7Bill Wendling SawPotentiallyThrowing |= !CallToNoUnwindFunction(MI); 52673b55510585573cd37fca85864c8d7d73e6b4093Bill Wendling 527eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling continue; 528eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 529eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 530eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling unsigned BeginLabel = MI->getOperand(0).getImm(); 531eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling assert(BeginLabel && "Invalid label!"); 532eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 533eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // End of the previous try-range? 534eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (BeginLabel == LastLabel) 535eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling SawPotentiallyThrowing = false; 536eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 537eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Beginning of a new try-range? 53881cf4325698b48b02eddab921ac333c7f25005c3Jeffrey Yasskin RangeMapType::const_iterator L = PadMap.find(BeginLabel); 539eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (L == PadMap.end()) 540eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Nope, it was just some random label. 541eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling continue; 542eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 543a583c55864e83e470333b7be878280b10e175a6eBill Wendling const PadRange &P = L->second; 544eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling const LandingPadInfo *LandingPad = LandingPads[P.PadIndex]; 545eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] && 546eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling "Inconsistent landing pad map!"); 547eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 548a583c55864e83e470333b7be878280b10e175a6eBill Wendling // For Dwarf exception handling (SjLj handling doesn't use this). If some 549a583c55864e83e470333b7be878280b10e175a6eBill Wendling // instruction between the previous try-range and this one may throw, 550a583c55864e83e470333b7be878280b10e175a6eBill Wendling // create a call-site entry with no landing pad for the region between the 551a583c55864e83e470333b7be878280b10e175a6eBill Wendling // try-ranges. 5521b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach if (SawPotentiallyThrowing && 55333adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner MAI->getExceptionHandlingType() == ExceptionHandling::Dwarf) { 554a583c55864e83e470333b7be878280b10e175a6eBill Wendling CallSiteEntry Site = { LastLabel, BeginLabel, 0, 0 }; 555eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling CallSites.push_back(Site); 556eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling PreviousIsInvoke = false; 557eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 558eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 559eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling LastLabel = LandingPad->EndLabels[P.RangeIndex]; 560eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling assert(BeginLabel && LastLabel && "Invalid landing pad!"); 561eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 562eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (LandingPad->LandingPadLabel) { 563eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // This try-range is for an invoke. 564a583c55864e83e470333b7be878280b10e175a6eBill Wendling CallSiteEntry Site = { 565a583c55864e83e470333b7be878280b10e175a6eBill Wendling BeginLabel, 566a583c55864e83e470333b7be878280b10e175a6eBill Wendling LastLabel, 567a583c55864e83e470333b7be878280b10e175a6eBill Wendling LandingPad->LandingPadLabel, 568a583c55864e83e470333b7be878280b10e175a6eBill Wendling FirstActions[P.PadIndex] 569a583c55864e83e470333b7be878280b10e175a6eBill Wendling }; 570eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 57133668c0f1a7e374d4c3c53df34efbdf570e0987bJim Grosbach // Try to merge with the previous call-site. SJLJ doesn't do this 57233668c0f1a7e374d4c3c53df34efbdf570e0987bJim Grosbach if (PreviousIsInvoke && 57333668c0f1a7e374d4c3c53df34efbdf570e0987bJim Grosbach MAI->getExceptionHandlingType() == ExceptionHandling::Dwarf) { 574eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling CallSiteEntry &Prev = CallSites.back(); 575eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) { 576eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Extend the range of the previous entry. 577eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling Prev.EndLabel = Site.EndLabel; 578eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling continue; 579eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 580eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 581eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 582eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Otherwise, create a new call-site. 583ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach if (MAI->getExceptionHandlingType() == ExceptionHandling::Dwarf) 584ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach CallSites.push_back(Site); 585ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach else { 586ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach // SjLj EH must maintain the call sites in the order assigned 587ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach // to them by the SjLjPrepare pass. 588ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach unsigned SiteNo = MMI->getCallSiteBeginLabel(BeginLabel); 589ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach if (CallSites.size() < SiteNo) 590ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach CallSites.resize(SiteNo); 591ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach CallSites[SiteNo - 1] = Site; 592ca752c9020a1b1cf151142bd9e0cbca9af12d807Jim Grosbach } 593eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling PreviousIsInvoke = true; 594eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } else { 595eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Create a gap. 596eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling PreviousIsInvoke = false; 597eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 598eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 599eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 600eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 601eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // If some instruction between the previous try-range and the end of the 602eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // function may throw, create a call-site entry with no landing pad for the 603eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // region following the try-range. 6041b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach if (SawPotentiallyThrowing && 60533adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner MAI->getExceptionHandlingType() == ExceptionHandling::Dwarf) { 606a583c55864e83e470333b7be878280b10e175a6eBill Wendling CallSiteEntry Site = { LastLabel, 0, 0, 0 }; 607eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling CallSites.push_back(Site); 608eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 609ade025c65c12503aba161a4fa399fd97414abaffBill Wendling} 610ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 6110dafca90761097230f02e655fdd541f59b888315Bill Wendling/// EmitExceptionTable - Emit landing pads and actions. 6120dafca90761097230f02e655fdd541f59b888315Bill Wendling/// 6130dafca90761097230f02e655fdd541f59b888315Bill Wendling/// The general organization of the table is complex, but the basic concepts are 6140dafca90761097230f02e655fdd541f59b888315Bill Wendling/// easy. First there is a header which describes the location and organization 6150dafca90761097230f02e655fdd541f59b888315Bill Wendling/// of the three components that follow. 616dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher/// 6170dafca90761097230f02e655fdd541f59b888315Bill Wendling/// 1. The landing pad site information describes the range of code covered by 6180dafca90761097230f02e655fdd541f59b888315Bill Wendling/// the try. In our case it's an accumulation of the ranges covered by the 6190dafca90761097230f02e655fdd541f59b888315Bill Wendling/// invokes in the try. There is also a reference to the landing pad that 6200dafca90761097230f02e655fdd541f59b888315Bill Wendling/// handles the exception once processed. Finally an index into the actions 6210dafca90761097230f02e655fdd541f59b888315Bill Wendling/// table. 622a583c55864e83e470333b7be878280b10e175a6eBill Wendling/// 2. The action table, in our case, is composed of pairs of type IDs and next 6230dafca90761097230f02e655fdd541f59b888315Bill Wendling/// action offset. Starting with the action index from the landing pad 624a583c55864e83e470333b7be878280b10e175a6eBill Wendling/// site, each type ID is checked for a match to the current exception. If 6250dafca90761097230f02e655fdd541f59b888315Bill Wendling/// it matches then the exception and type id are passed on to the landing 6260dafca90761097230f02e655fdd541f59b888315Bill Wendling/// pad. Otherwise the next action is looked up. This chain is terminated 62728275fdf02885587156da5cb20388b22d5b96557Bill Wendling/// with a next action of zero. If no type id is found then the frame is 6280dafca90761097230f02e655fdd541f59b888315Bill Wendling/// unwound and handling continues. 629a583c55864e83e470333b7be878280b10e175a6eBill Wendling/// 3. Type ID table contains references to all the C++ typeinfo for all 63028275fdf02885587156da5cb20388b22d5b96557Bill Wendling/// catches in the function. This tables is reverse indexed base 1. 631ade025c65c12503aba161a4fa399fd97414abaffBill Wendlingvoid DwarfException::EmitExceptionTable() { 632ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos(); 633ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const std::vector<unsigned> &FilterIds = MMI->getFilterIds(); 634ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads(); 635ade025c65c12503aba161a4fa399fd97414abaffBill Wendling if (PadInfos.empty()) return; 636ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 637ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // Sort the landing pads in order of their type ids. This is used to fold 638ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // duplicate actions. 639ade025c65c12503aba161a4fa399fd97414abaffBill Wendling SmallVector<const LandingPadInfo *, 64> LandingPads; 640ade025c65c12503aba161a4fa399fd97414abaffBill Wendling LandingPads.reserve(PadInfos.size()); 641ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 642ade025c65c12503aba161a4fa399fd97414abaffBill Wendling for (unsigned i = 0, N = PadInfos.size(); i != N; ++i) 643ade025c65c12503aba161a4fa399fd97414abaffBill Wendling LandingPads.push_back(&PadInfos[i]); 644ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 645ade025c65c12503aba161a4fa399fd97414abaffBill Wendling std::sort(LandingPads.begin(), LandingPads.end(), PadLT); 646ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 647ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // Compute the actions table and gather the first action index for each 648ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // landing pad site. 649ade025c65c12503aba161a4fa399fd97414abaffBill Wendling SmallVector<ActionEntry, 32> Actions; 650ade025c65c12503aba161a4fa399fd97414abaffBill Wendling SmallVector<unsigned, 64> FirstActions; 65128275fdf02885587156da5cb20388b22d5b96557Bill Wendling unsigned SizeActions = ComputeActionsTable(LandingPads, Actions, 65228275fdf02885587156da5cb20388b22d5b96557Bill Wendling FirstActions); 653ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 654ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // Invokes and nounwind calls have entries in PadMap (due to being bracketed 655ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // by try-range labels when lowered). Ordinary calls do not, so appropriate 65628275fdf02885587156da5cb20388b22d5b96557Bill Wendling // try-ranges for them need be deduced when using DWARF exception handling. 657ade025c65c12503aba161a4fa399fd97414abaffBill Wendling RangeMapType PadMap; 658ade025c65c12503aba161a4fa399fd97414abaffBill Wendling for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) { 659ade025c65c12503aba161a4fa399fd97414abaffBill Wendling const LandingPadInfo *LandingPad = LandingPads[i]; 660ade025c65c12503aba161a4fa399fd97414abaffBill Wendling for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) { 661ade025c65c12503aba161a4fa399fd97414abaffBill Wendling unsigned BeginLabel = LandingPad->BeginLabels[j]; 662ade025c65c12503aba161a4fa399fd97414abaffBill Wendling assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!"); 663ade025c65c12503aba161a4fa399fd97414abaffBill Wendling PadRange P = { i, j }; 664ade025c65c12503aba161a4fa399fd97414abaffBill Wendling PadMap[BeginLabel] = P; 665ade025c65c12503aba161a4fa399fd97414abaffBill Wendling } 666ade025c65c12503aba161a4fa399fd97414abaffBill Wendling } 667ade025c65c12503aba161a4fa399fd97414abaffBill Wendling 668ade025c65c12503aba161a4fa399fd97414abaffBill Wendling // Compute the call-site table. 669ade025c65c12503aba161a4fa399fd97414abaffBill Wendling SmallVector<CallSiteEntry, 64> CallSites; 6708b818d7e98309125c6058c4ea72a7dc73b031db2Jim Grosbach ComputeCallSiteTable(CallSites, PadMap, LandingPads, FirstActions); 671eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 672eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Final tallies. 673eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 674eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Call sites. 67540121bccbee44d387ab5d6a5194c5fc27c542e12Bill Wendling const unsigned SiteStartSize = SizeOfEncodedValue(dwarf::DW_EH_PE_udata4); 67640121bccbee44d387ab5d6a5194c5fc27c542e12Bill Wendling const unsigned SiteLengthSize = SizeOfEncodedValue(dwarf::DW_EH_PE_udata4); 67740121bccbee44d387ab5d6a5194c5fc27c542e12Bill Wendling const unsigned LandingPadSize = SizeOfEncodedValue(dwarf::DW_EH_PE_udata4); 678d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling bool IsSJLJ = MAI->getExceptionHandlingType() == ExceptionHandling::SjLj; 679d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling bool HaveTTData = IsSJLJ ? (!TypeInfos.empty() || !FilterIds.empty()) : true; 68028275fdf02885587156da5cb20388b22d5b96557Bill Wendling unsigned SizeSites; 681d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling 682d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling if (IsSJLJ) 6838b818d7e98309125c6058c4ea72a7dc73b031db2Jim Grosbach SizeSites = 0; 684d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling else 6851b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach SizeSites = CallSites.size() * 6861b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach (SiteStartSize + SiteLengthSize + LandingPadSize); 687d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling 6881b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach for (unsigned i = 0, e = CallSites.size(); i < e; ++i) { 689af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner SizeSites += MCAsmInfo::getULEB128Size(CallSites[i].Action); 690d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling if (IsSJLJ) 691af76e592c7f9deff0e55c13dbb4a34f07f1c7f64Chris Lattner SizeSites += MCAsmInfo::getULEB128Size(i); 6921b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach } 693d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling 694eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling // Type infos. 695d5bbb07ec806e6fa1e804afd7073987fdacc83e4Chris Lattner const MCSection *LSDASection = Asm->getObjFileLowering().getLSDASection(); 696fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling unsigned TTypeFormat; 697a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling unsigned TypeFormatSize; 698eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 69943e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling if (!HaveTTData) { 70028275fdf02885587156da5cb20388b22d5b96557Bill Wendling // For SjLj exceptions, if there is no TypeInfo, then we just explicitly say 70128275fdf02885587156da5cb20388b22d5b96557Bill Wendling // that we're omitting that bit. 702fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling TTypeFormat = dwarf::DW_EH_PE_omit; 703a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling TypeFormatSize = SizeOfEncodedValue(dwarf::DW_EH_PE_absptr); 70481c9a069377e9474d010f04eebe8325fd11429e3Chris Lattner } else { 705ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // Okay, we have actual filters or typeinfos to emit. As such, we need to 706ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // pick a type encoding for them. We're about to emit a list of pointers to 707ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // typeinfo objects at the end of the LSDA. However, unless we're in static 708ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // mode, this reference will require a relocation by the dynamic linker. 70946b754c76bd6a720dd1dd3be248cb93a4e25d3e5Chris Lattner // 710ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // Because of this, we have a couple of options: 71128275fdf02885587156da5cb20388b22d5b96557Bill Wendling // 712ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // 1) If we are in -static mode, we can always use an absolute reference 713ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // from the LSDA, because the static linker will resolve it. 71428275fdf02885587156da5cb20388b22d5b96557Bill Wendling // 715ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // 2) Otherwise, if the LSDA section is writable, we can output the direct 716ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // reference to the typeinfo and allow the dynamic linker to relocate 717ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // it. Since it is in a writable section, the dynamic linker won't 718ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // have a problem. 71928275fdf02885587156da5cb20388b22d5b96557Bill Wendling // 720ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // 3) Finally, if we're in PIC mode and the LDSA section isn't writable, 721ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // we need to use some form of indirection. For example, on Darwin, 722ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // we can output a statically-relocatable reference to a dyld stub. The 723ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // offset to the stub is constant, but the contents are in a section 724ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // that is updated by the dynamic linker. This is easy enough, but we 725ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // need to tell the personality function of the unwinder to indirect 726ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // through the dyld stub. 727ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // 72843e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling // FIXME: When (3) is actually implemented, we'll have to emit the stubs 729ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // somewhere. This predicate should be moved to a shared location that is 730ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // in target-independent code. 731ad88bc4076d088baad8a5ee9561e46ac08a1c88aChris Lattner // 732fb7634f1c7a804829fc55e3711ba62c8ade818d0Bill Wendling if (LSDASection->getKind().isWriteable() || 73343e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling Asm->TM.getRelocationModel() == Reloc::Static) 73443e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling TTypeFormat = dwarf::DW_EH_PE_absptr; 73543e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling else 73643e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling TTypeFormat = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 73743e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling dwarf::DW_EH_PE_sdata4; 738a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling 739a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling TypeFormatSize = SizeOfEncodedValue(TTypeFormat); 740fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling } 741fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling 742fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling // Begin the exception table. 743fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling Asm->OutStreamer.SwitchSection(LSDASection); 744fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling Asm->EmitAlignment(2, 0, 0, false); 74543e484fbcf6a40a70d9a5c7ea142f37416ef1e68Bill Wendling 746fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling O << "GCC_except_table" << SubprogramCount << ":\n"; 747a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling 748a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // The type infos need to be aligned. GCC does this by inserting padding just 749a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // before the type infos. However, this changes the size of the exception 750a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // table, so you need to take this into account when you output the exception 751a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // table size. However, the size is output using a variable length encoding. 752a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // So by increasing the size by inserting padding, you may increase the number 753a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // of bytes used for writing the size. If it increases, say by one byte, then 754a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // you now need to output one less byte of padding to get the type infos 755a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // aligned. However this decreases the size of the exception table. This 756a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // changes the value you have to output for the exception table size. Due to 757a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // the variable length encoding, the number of bytes used for writing the 758a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // length may decrease. If so, you then have to increase the amount of 759a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // padding. And so on. If you look carefully at the GCC code you will see that 760a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // it indeed does this in a loop, going on and on until the values stabilize. 761a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // We chose another solution: don't output padding inside the table like GCC 762a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling // does, instead output it before the table. 763a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling unsigned SizeTypes = TypeInfos.size() * TypeFormatSize; 764a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling unsigned TyOffset = sizeof(int8_t) + // Call site format 765a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling MCAsmInfo::getULEB128Size(SizeSites) + // Call-site table length 766a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling SizeSites + SizeActions + SizeTypes; 767a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling unsigned TotalSize = sizeof(int8_t) + // LPStart format 768a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling sizeof(int8_t) + // TType format 769a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling (HaveTTData ? 770a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling MCAsmInfo::getULEB128Size(TyOffset) : 0) + // TType base offset 771a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling TyOffset; 772a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling unsigned SizeAlign = (4 - TotalSize) & 3; 773a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling 774a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling for (unsigned i = 0; i != SizeAlign; ++i) { 775a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling Asm->EmitInt8(0); 776faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Padding"); 777a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling } 778a2f6449a57fcce73beacc30158aafe39b5349947Bill Wendling 779fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling EmitLabel("exception", SubprogramCount); 780fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling 781fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling if (IsSJLJ) { 782fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling SmallString<16> LSDAName; 783fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling raw_svector_ostream(LSDAName) << MAI->getPrivateGlobalPrefix() << 784fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling "_LSDA_" << Asm->getFunctionNumber(); 785fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling O << LSDAName.str() << ":\n"; 786fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling } 787fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling 788fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling // Emit the header. 789f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(dwarf::DW_EH_PE_omit, "@LPStart"); 790f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(TTypeFormat, "@TType"); 791fe220285b5ef1e4480ddd7f7c8bb182b88a33b16Bill Wendling 792894d75aa013143c92890d0205791d0d70a453114Chris Lattner if (HaveTTData) 793894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(TyOffset, "@TType base offset"); 794b0d9c3e7fdc952ae7cbe169b01ccaf1b80329403Bill Wendling 79528275fdf02885587156da5cb20388b22d5b96557Bill Wendling // SjLj Exception handling 796d1a5b37a62e829e56b6225e0934a01d9f8823387Bill Wendling if (IsSJLJ) { 797f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(dwarf::DW_EH_PE_udata4, "Call site"); 798894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(SizeSites, "Call site table length"); 7991b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach 8001b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach // Emit the landing pad site information. 8018b818d7e98309125c6058c4ea72a7dc73b031db2Jim Grosbach unsigned idx = 0; 8028b818d7e98309125c6058c4ea72a7dc73b031db2Jim Grosbach for (SmallVectorImpl<CallSiteEntry>::const_iterator 8038b818d7e98309125c6058c4ea72a7dc73b031db2Jim Grosbach I = CallSites.begin(), E = CallSites.end(); I != E; ++I, ++idx) { 8048b818d7e98309125c6058c4ea72a7dc73b031db2Jim Grosbach const CallSiteEntry &S = *I; 805a583c55864e83e470333b7be878280b10e175a6eBill Wendling 806a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Offset of the landing pad, counted in 16-byte bundles relative to the 807a583c55864e83e470333b7be878280b10e175a6eBill Wendling // @LPStart address. 808894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(idx, "Landing pad"); 809a583c55864e83e470333b7be878280b10e175a6eBill Wendling 810a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Offset of the first associated action record, relative to the start of 811a583c55864e83e470333b7be878280b10e175a6eBill Wendling // the action table. This value is biased by 1 (1 indicates the start of 812a583c55864e83e470333b7be878280b10e175a6eBill Wendling // the action table), and 0 indicates that there are no actions. 813894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(S.Action, "Action"); 8141b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach } 8151b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach } else { 8161b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach // DWARF Exception handling 81733adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner assert(MAI->getExceptionHandlingType() == ExceptionHandling::Dwarf); 8181b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach 819a583c55864e83e470333b7be878280b10e175a6eBill Wendling // The call-site table is a list of all call sites that may throw an 820a583c55864e83e470333b7be878280b10e175a6eBill Wendling // exception (including C++ 'throw' statements) in the procedure 821a583c55864e83e470333b7be878280b10e175a6eBill Wendling // fragment. It immediately follows the LSDA header. Each entry indicates, 822a583c55864e83e470333b7be878280b10e175a6eBill Wendling // for a given call, the first corresponding action record and corresponding 823a583c55864e83e470333b7be878280b10e175a6eBill Wendling // landing pad. 824a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 825a583c55864e83e470333b7be878280b10e175a6eBill Wendling // The table begins with the number of bytes, stored as an LEB128 826a583c55864e83e470333b7be878280b10e175a6eBill Wendling // compressed, unsigned integer. The records immediately follow the record 827a583c55864e83e470333b7be878280b10e175a6eBill Wendling // count. They are sorted in increasing call-site address. Each record 828a583c55864e83e470333b7be878280b10e175a6eBill Wendling // indicates: 829a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 830a583c55864e83e470333b7be878280b10e175a6eBill Wendling // * The position of the call-site. 831a583c55864e83e470333b7be878280b10e175a6eBill Wendling // * The position of the landing pad. 832a583c55864e83e470333b7be878280b10e175a6eBill Wendling // * The first action record for that call site. 833a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 834a583c55864e83e470333b7be878280b10e175a6eBill Wendling // A missing entry in the call-site table indicates that a call is not 83528275fdf02885587156da5cb20388b22d5b96557Bill Wendling // supposed to throw. 836a583c55864e83e470333b7be878280b10e175a6eBill Wendling 837a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Emit the landing pad call site table. 838f61ed8eb32aa1cfcb440742e6fbaa7c785647131Chris Lattner EmitEncodingByte(dwarf::DW_EH_PE_udata4, "Call site"); 839894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(SizeSites, "Call site table size"); 840eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 8411b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach for (SmallVectorImpl<CallSiteEntry>::const_iterator 8425cff487665097d971067cbede1598e249f673182Bill Wendling I = CallSites.begin(), E = CallSites.end(); I != E; ++I) { 8431b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach const CallSiteEntry &S = *I; 8441b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach const char *BeginTag; 8451b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach unsigned BeginNumber; 846eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 8471b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach if (!S.BeginLabel) { 8481b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach BeginTag = "eh_func_begin"; 8491b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach BeginNumber = SubprogramCount; 8501b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach } else { 8511b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach BeginTag = "label"; 8521b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach BeginNumber = S.BeginLabel; 8531b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach } 854eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 855a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Offset of the call site relative to the previous call site, counted in 856a583c55864e83e470333b7be878280b10e175a6eBill Wendling // number of 16-byte bundles. The first call site is counted relative to 857a583c55864e83e470333b7be878280b10e175a6eBill Wendling // the start of the procedure fragment. 8581b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount, 8591b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach true, true); 860faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Region start"); 861eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 8621b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach if (!S.EndLabel) 8631b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber, 8641b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach true); 8651b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach else 8661b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach EmitDifference("label", S.EndLabel, BeginTag, BeginNumber, true); 867eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 868faca5497a26672669934abbcf23894ce93408c10Chris Lattner EOL("Region length"); 869eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 870a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Offset of the landing pad, counted in 16-byte bundles relative to the 871a583c55864e83e470333b7be878280b10e175a6eBill Wendling // @LPStart address. 8721f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling if (!S.PadLabel) { 8731f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling Asm->OutStreamer.AddComment("Landing pad"); 874bcb83e5b6c8e074e73986cb641801ecbedd6e4edChris Lattner Asm->OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/); 8751f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling } else { 8761b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount, 8771b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach true, true); 8781f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EOL("Landing pad"); 8791f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling } 880eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 881a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Offset of the first associated action record, relative to the start of 882a583c55864e83e470333b7be878280b10e175a6eBill Wendling // the action table. This value is biased by 1 (1 indicates the start of 883a583c55864e83e470333b7be878280b10e175a6eBill Wendling // the action table), and 0 indicates that there are no actions. 884894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(S.Action, "Action"); 8851b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach } 886eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 887eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 888a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Emit the Action Table. 8891f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EOL("Action Record Table:"); 8901f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling unsigned Iter = 1; 8915cff487665097d971067cbede1598e249f673182Bill Wendling for (SmallVectorImpl<ActionEntry>::const_iterator 8925cff487665097d971067cbede1598e249f673182Bill Wendling I = Actions.begin(), E = Actions.end(); I != E; ++I) { 8935cff487665097d971067cbede1598e249f673182Bill Wendling const ActionEntry &Action = *I; 8941f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EOL(Twine("Action Record ") + Twine(Iter++)); 895a583c55864e83e470333b7be878280b10e175a6eBill Wendling 896a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Type Filter 897a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 898a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Used by the runtime to match the type of the thrown exception to the 899a583c55864e83e470333b7be878280b10e175a6eBill Wendling // type of the catch clauses or the types in the exception specification. 9001f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EmitSLEB128(Action.ValueForTypeID, " TypeInfo index"); 901a583c55864e83e470333b7be878280b10e175a6eBill Wendling 902a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Action Record 903a583c55864e83e470333b7be878280b10e175a6eBill Wendling // 904a583c55864e83e470333b7be878280b10e175a6eBill Wendling // Self-relative signed displacement in bytes of the next action record, 905a583c55864e83e470333b7be878280b10e175a6eBill Wendling // or 0 if there is no next action record. 9061f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EmitSLEB128(Action.NextAction, " Next action"); 907eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 908eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 90948dc29ef911a223a52b099604d0ccb499ecbf703Bill Wendling // Emit the Catch TypeInfos. 9101f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling Iter = TypeInfos.size(); 9115cff487665097d971067cbede1598e249f673182Bill Wendling for (std::vector<GlobalVariable *>::const_reverse_iterator 91201c69374b508bad0ee71cd3c49414a325238e29aBill Wendling I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) { 913fb7634f1c7a804829fc55e3711ba62c8ade818d0Bill Wendling const GlobalVariable *GV = *I; 914fb7634f1c7a804829fc55e3711ba62c8ade818d0Bill Wendling PrintRelDirective(); 915fb7634f1c7a804829fc55e3711ba62c8ade818d0Bill Wendling 9161f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling if (GV) { 91710b318bcb39218d2ed525e4862c854bc8d1baf63Chris Lattner O << *Asm->GetGlobalValueSymbol(GV); 9181f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EOL(Twine("TypeInfo ") + Twine(Iter--)); 9191f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling } else { 920049e98d641f90e90e8312d76cbf4c68908fb9d1dBill Wendling O << "0x0"; 9211f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling EOL(""); 9221f8075d7d232dd0c7b0caa81ed3ce426a13f5a66Bill Wendling } 923eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 924eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 92548dc29ef911a223a52b099604d0ccb499ecbf703Bill Wendling // Emit the Exception Specifications. 9265cff487665097d971067cbede1598e249f673182Bill Wendling for (std::vector<unsigned>::const_iterator 9275cff487665097d971067cbede1598e249f673182Bill Wendling I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) { 9285cff487665097d971067cbede1598e249f673182Bill Wendling unsigned TypeID = *I; 929894d75aa013143c92890d0205791d0d70a453114Chris Lattner EmitULEB128(TypeID, TypeID != 0 ? "Exception specification" : 0); 930eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling } 931eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 932eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling Asm->EmitAlignment(2, 0, 0, false); 933eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 934eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 935eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling/// EndModule - Emit all exception information that should come after the 936eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling/// content. 937eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendlingvoid DwarfException::EndModule() { 93833adcfb4d217f5f23d9bde8ba02b8e48f9605fc5Chris Lattner if (MAI->getExceptionHandlingType() != ExceptionHandling::Dwarf) 9391b747ad8a0694b86e8d98a8b9a05ddfe74ec0cd3Jim Grosbach return; 940b4049fe8cbb38416522f7b214f028ef0b7693d21Bill Wendling 94152783c63a13d384582997684384553e6545852d3Bill Wendling if (!shouldEmitMovesModule && !shouldEmitTableModule) 94252783c63a13d384582997684384553e6545852d3Bill Wendling return; 94352783c63a13d384582997684384553e6545852d3Bill Wendling 944eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (TimePassesIsEnabled) 945eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ExceptionTimer->startTimer(); 946eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 94752783c63a13d384582997684384553e6545852d3Bill Wendling const std::vector<Function *> Personalities = MMI->getPersonalities(); 948b4049fe8cbb38416522f7b214f028ef0b7693d21Bill Wendling 94928275fdf02885587156da5cb20388b22d5b96557Bill Wendling for (unsigned I = 0, E = Personalities.size(); I < E; ++I) 95028275fdf02885587156da5cb20388b22d5b96557Bill Wendling EmitCIE(Personalities[I], I); 951eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 95252783c63a13d384582997684384553e6545852d3Bill Wendling for (std::vector<FunctionEHFrameInfo>::iterator 95352783c63a13d384582997684384553e6545852d3Bill Wendling I = EHFrames.begin(), E = EHFrames.end(); I != E; ++I) 95452783c63a13d384582997684384553e6545852d3Bill Wendling EmitFDE(*I); 955eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 956eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (TimePassesIsEnabled) 957eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ExceptionTimer->stopTimer(); 958eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 959eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 96028275fdf02885587156da5cb20388b22d5b96557Bill Wendling/// BeginFunction - Gather pre-function exception information. Assumes it's 96128275fdf02885587156da5cb20388b22d5b96557Bill Wendling/// being emitted immediately after the function entry point. 962eec791afb127ed634ed5d1cdd2e6c47b3b70174cChris Lattnervoid DwarfException::BeginFunction(const MachineFunction *MF) { 96373c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling if (!MMI || !MAI->doesSupportExceptionHandling()) return; 96473c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling 965eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (TimePassesIsEnabled) 966eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ExceptionTimer->startTimer(); 967eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 968eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling this->MF = MF; 969eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling shouldEmitTable = shouldEmitMoves = false; 970eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 97173c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling // Map all labels and get rid of any dead landing pads. 97273c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling MMI->TidyLandingPads(); 973eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 97473c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling // If any landing pads survive, we need an EH table. 97573c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling if (!MMI->getLandingPads().empty()) 97673c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling shouldEmitTable = true; 977eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 97873c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling // See if we need frame move info. 97973c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling if (!MF->getFunction()->doesNotThrow() || UnwindTablesMandatory) 98073c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling shouldEmitMoves = true; 981eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 98273c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling if (shouldEmitMoves || shouldEmitTable) 98373c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling // Assumes in correct section after the entry point. 98473c5a6172508e957d0b1a46170cb070dce6cac4fBill Wendling EmitLabel("eh_func_begin", ++SubprogramCount); 985eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 986eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling shouldEmitTableModule |= shouldEmitTable; 987eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling shouldEmitMovesModule |= shouldEmitMoves; 988eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 989eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling if (TimePassesIsEnabled) 990eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ExceptionTimer->stopTimer(); 991eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 992eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 993eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling/// EndFunction - Gather and emit post-function exception information. 994eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling/// 995eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendlingvoid DwarfException::EndFunction() { 9967b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling if (!shouldEmitMoves && !shouldEmitTable) return; 9977b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling 998dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher if (TimePassesIsEnabled) 999eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ExceptionTimer->startTimer(); 1000eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 10017b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling EmitLabel("eh_func_end", SubprogramCount); 10027b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling EmitExceptionTable(); 10037b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling 10043a9be0ee36fe2143f514d28315f3dc1bda132b2eChris Lattner MCSymbol *FunctionEHSym = 10057a2ba94d03b43f41b54872dacd7b2250dde4c7bdChris Lattner Asm->GetSymbolWithGlobalValueBase(MF->getFunction(), ".eh", 10067a2ba94d03b43f41b54872dacd7b2250dde4c7bdChris Lattner Asm->MAI->is_EHSymbolPrivate()); 100725d812bd7d1f58f2ba1b598b1425a2e146e27381Chris Lattner 10087b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling // Save EH frame information 10097a2ba94d03b43f41b54872dacd7b2250dde4c7bdChris Lattner EHFrames.push_back(FunctionEHFrameInfo(FunctionEHSym, SubprogramCount, 10107b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling MMI->getPersonalityIndex(), 10117b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling MF->getFrameInfo()->hasCalls(), 10127b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling !MMI->getLandingPads().empty(), 10137b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling MMI->getFrameMoves(), 10147b09a6c62215e5ed30443b0d2b2a5ae18b89b94fBill Wendling MF->getFunction())); 1015eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling 101652783c63a13d384582997684384553e6545852d3Bill Wendling // Record if this personality index uses a landing pad. 101752783c63a13d384582997684384553e6545852d3Bill Wendling UsesLSDA[MMI->getPersonalityIndex()] |= !MMI->getLandingPads().empty(); 101852783c63a13d384582997684384553e6545852d3Bill Wendling 1019dbfcdb976367ad5a9d3541fef90cd9f8dde7e2b4Eric Christopher if (TimePassesIsEnabled) 1020eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling ExceptionTimer->stopTimer(); 1021eb9072195ca7d777a71194dcaaaa369d82f24f53Bill Wendling} 1022