ARMException.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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"
37using namespace llvm;
38
39ARMException::ARMException(AsmPrinter *A)
40  : DwarfException(A),
41    shouldEmitCFI(false) {}
42
43ARMException::~ARMException() {}
44
45ARMTargetStreamer &ARMException::getTargetStreamer() {
46  MCTargetStreamer &TS = *Asm->OutStreamer.getTargetStreamer();
47  return static_cast<ARMTargetStreamer &>(TS);
48}
49
50/// endModule - Emit all exception information that should come after the
51/// content.
52void ARMException::endModule() {
53  if (shouldEmitCFI)
54    Asm->OutStreamer.EmitCFISections(false, true);
55}
56
57/// beginFunction - Gather pre-function exception information. Assumes it's
58/// being emitted immediately after the function entry point.
59void ARMException::beginFunction(const MachineFunction *MF) {
60  if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
61    getTargetStreamer().emitFnStart();
62  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
63                                                Asm->getFunctionNumber()));
64  // See if we need call frame info.
65  AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
66  assert(MoveType != AsmPrinter::CFI_M_EH &&
67         "non-EH CFI not yet supported in prologue with EHABI lowering");
68  if (MoveType == AsmPrinter::CFI_M_Debug) {
69    shouldEmitCFI = true;
70    Asm->OutStreamer.EmitCFIStartProc(false);
71  }
72}
73
74/// endFunction - Gather and emit post-function exception information.
75///
76void ARMException::endFunction(const MachineFunction *) {
77  if (shouldEmitCFI)
78    Asm->OutStreamer.EmitCFIEndProc();
79
80  // Map all labels and get rid of any dead landing pads.
81  MMI->TidyLandingPads();
82
83  ARMTargetStreamer &ATS = getTargetStreamer();
84  if (!Asm->MF->getFunction()->needsUnwindTableEntry() &&
85      MMI->getLandingPads().empty())
86    ATS.emitCantUnwind();
87  else {
88    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
89                                                  Asm->getFunctionNumber()));
90    if (!MMI->getLandingPads().empty()) {
91      // Emit references to personality.
92      if (const Function * Personality =
93          MMI->getPersonalities()[MMI->getPersonalityIndex()]) {
94        MCSymbol *PerSym = Asm->getSymbol(Personality);
95        Asm->OutStreamer.EmitSymbolAttribute(PerSym, MCSA_Global);
96        ATS.emitPersonality(PerSym);
97      }
98
99      // Emit .handlerdata directive.
100      ATS.emitHandlerData();
101
102      // Emit actual exception table
103      EmitExceptionTable();
104    }
105  }
106
107  if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
108    ATS.emitFnEnd();
109}
110
111void ARMException::EmitTypeInfos(unsigned TTypeEncoding) {
112  const std::vector<const GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
113  const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
114
115  bool VerboseAsm = Asm->OutStreamer.isVerboseAsm();
116
117  int Entry = 0;
118  // Emit the Catch TypeInfos.
119  if (VerboseAsm && !TypeInfos.empty()) {
120    Asm->OutStreamer.AddComment(">> Catch TypeInfos <<");
121    Asm->OutStreamer.AddBlankLine();
122    Entry = TypeInfos.size();
123  }
124
125  for (std::vector<const GlobalVariable *>::const_reverse_iterator
126         I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) {
127    const GlobalVariable *GV = *I;
128    if (VerboseAsm)
129      Asm->OutStreamer.AddComment("TypeInfo " + Twine(Entry--));
130    Asm->EmitTTypeReference(GV, TTypeEncoding);
131  }
132
133  // Emit the Exception Specifications.
134  if (VerboseAsm && !FilterIds.empty()) {
135    Asm->OutStreamer.AddComment(">> Filter TypeInfos <<");
136    Asm->OutStreamer.AddBlankLine();
137    Entry = 0;
138  }
139  for (std::vector<unsigned>::const_iterator
140         I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
141    unsigned TypeID = *I;
142    if (VerboseAsm) {
143      --Entry;
144      if (TypeID != 0)
145        Asm->OutStreamer.AddComment("FilterInfo " + Twine(Entry));
146    }
147
148    Asm->EmitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]),
149                            TTypeEncoding);
150  }
151}
152