src/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp

   1 //===-- CodeGen/AsmPrinter/ARMException.cpp - ARM EHABI Exception Impl ----===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file contains support for writing DWARF exception info into asm files.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "DwarfException.h"
  15 #include "llvm/ADT/SmallString.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include "llvm/ADT/Twine.h"
  18 #include "llvm/CodeGen/AsmPrinter.h"
  19 #include "llvm/CodeGen/MachineFrameInfo.h"
  20 #include "llvm/CodeGen/MachineFunction.h"
  21 #include "llvm/CodeGen/MachineModuleInfo.h"
  22 #include "llvm/IR/DataLayout.h"
  23 #include "llvm/IR/Mangler.h"
  24 #include "llvm/IR/Module.h"
  25 #include "llvm/MC/MCAsmInfo.h"
  26 #include "llvm/MC/MCContext.h"
  27 #include "llvm/MC/MCExpr.h"
  28 #include "llvm/MC/MCSection.h"
  29 #include "llvm/MC/MCStreamer.h"
  30 #include "llvm/MC/MCSymbol.h"
  31 #include "llvm/Support/CommandLine.h"
  32 #include "llvm/Support/Dwarf.h"
  33 #include "llvm/Support/FormattedStream.h"
  34 #include "llvm/Target/TargetFrameLowering.h"
  35 #include "llvm/Target/TargetOptions.h"
  36 #include "llvm/Target/TargetRegisterInfo.h"
  37 using namespace llvm;
  38
  39 ARMException::ARMException(AsmPrinter *A)
  40   : EHStreamer(A), shouldEmitCFI(false) {}
  41
  42 ARMException::~ARMException() {}
  43
  44 ARMTargetStreamer &ARMException::getTargetStreamer() {
  45   MCTargetStreamer &TS = *Asm->OutStreamer.getTargetStreamer();
  46   return static_cast<ARMTargetStreamer &>(TS);
  47 }
  48
  49 /// endModule - Emit all exception information that should come after the
  50 /// content.
  51 void ARMException::endModule() {
  52   if (shouldEmitCFI)
  53     Asm->OutStreamer.EmitCFISections(false, true);
  54 }
  55
  56 /// beginFunction - Gather pre-function exception information. Assumes it's
  57 /// being emitted immediately after the function entry point.
  58 void ARMException::beginFunction(const MachineFunction *MF) {
  59   if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
  60     getTargetStreamer().emitFnStart();
  61   Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
  62                                                 Asm->getFunctionNumber()));
  63   // See if we need call frame info.
  64   AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
  65   assert(MoveType != AsmPrinter::CFI_M_EH &&
  66          "non-EH CFI not yet supported in prologue with EHABI lowering");
  67   if (MoveType == AsmPrinter::CFI_M_Debug) {
  68     shouldEmitCFI = true;
  69     Asm->OutStreamer.EmitCFIStartProc(false);
  70   }
  71 }
  72
  73 /// endFunction - Gather and emit post-function exception information.
  74 ///
  75 void ARMException::endFunction(const MachineFunction *) {
  76   if (shouldEmitCFI)
  77     Asm->OutStreamer.EmitCFIEndProc();
  78
  79   // Map all labels and get rid of any dead landing pads.
  80   MMI->TidyLandingPads();
  81
  82   ARMTargetStreamer &ATS = getTargetStreamer();
  83   if (!Asm->MF->getFunction()->needsUnwindTableEntry() &&
  84       MMI->getLandingPads().empty())
  85     ATS.emitCantUnwind();
  86   else {
  87     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
  88                                                   Asm->getFunctionNumber()));
  89     if (!MMI->getLandingPads().empty()) {
  90       // Emit references to personality.
  91       if (const Function * Personality =
  92           MMI->getPersonalities()[MMI->getPersonalityIndex()]) {
  93         MCSymbol *PerSym = Asm->getSymbol(Personality);
  94         Asm->OutStreamer.EmitSymbolAttribute(PerSym, MCSA_Global);
  95         ATS.emitPersonality(PerSym);
  96       }
  97
  98       // Emit .handlerdata directive.
  99       ATS.emitHandlerData();
 100
 101       // Emit actual exception table
 102       emitExceptionTable();
 103     }
 104   }
 105
 106   if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
 107     ATS.emitFnEnd();
 108 }
 109
 110 void ARMException::emitTypeInfos(unsigned TTypeEncoding) {
 111   const std::vector<const GlobalValue *> &TypeInfos = MMI->getTypeInfos();
 112   const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
 113
 114   bool VerboseAsm = Asm->OutStreamer.isVerboseAsm();
 115
 116   int Entry = 0;
 117   // Emit the Catch TypeInfos.
 118   if (VerboseAsm && !TypeInfos.empty()) {
 119     Asm->OutStreamer.AddComment(">> Catch TypeInfos <<");
 120     Asm->OutStreamer.AddBlankLine();
 121     Entry = TypeInfos.size();
 122   }
 123
 124   for (std::vector<const GlobalValue *>::const_reverse_iterator
 125          I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) {
 126     const GlobalValue *GV = *I;
 127     if (VerboseAsm)
 128       Asm->OutStreamer.AddComment("TypeInfo " + Twine(Entry--));
 129     Asm->EmitTTypeReference(GV, TTypeEncoding);
 130   }
 131
 132   // Emit the Exception Specifications.
 133   if (VerboseAsm && !FilterIds.empty()) {
 134     Asm->OutStreamer.AddComment(">> Filter TypeInfos <<");
 135     Asm->OutStreamer.AddBlankLine();
 136     Entry = 0;
 137   }
 138   for (std::vector<unsigned>::const_iterator
 139          I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
 140     unsigned TypeID = *I;
 141     if (VerboseAsm) {
 142       --Entry;
 143       if (TypeID != 0)
 144         Asm->OutStreamer.AddComment("FilterInfo " + Twine(Entry));
 145     }
 146
 147     Asm->EmitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]),
 148                             TTypeEncoding);
 149   }
 150 }