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/Module.h"
24 #include "llvm/MC/MCAsmInfo.h"
25 #include "llvm/MC/MCContext.h"
26 #include "llvm/MC/MCExpr.h"
27 #include "llvm/MC/MCSection.h"
28 #include "llvm/MC/MCStreamer.h"
29 #include "llvm/MC/MCSymbol.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/Dwarf.h"
32 #include "llvm/Support/FormattedStream.h"
33 #include "llvm/Target/Mangler.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 static cl::opt<bool>
40 EnableARMEHABIDescriptors("arm-enable-ehabi-descriptors", cl::Hidden,
41 cl::desc("Generate ARM EHABI tables with unwinding descriptors"),
42 cl::init(false));
43
44
ARMException(AsmPrinter * A)45 ARMException::ARMException(AsmPrinter *A)
46 : DwarfException(A) {}
47
~ARMException()48 ARMException::~ARMException() {}
49
EndModule()50 void ARMException::EndModule() {
51 }
52
53 /// BeginFunction - Gather pre-function exception information. Assumes it's
54 /// being emitted immediately after the function entry point.
BeginFunction(const MachineFunction * MF)55 void ARMException::BeginFunction(const MachineFunction *MF) {
56 Asm->OutStreamer.EmitFnStart();
57 if (Asm->MF->getFunction()->needsUnwindTableEntry())
58 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
59 Asm->getFunctionNumber()));
60 }
61
62 /// EndFunction - Gather and emit post-function exception information.
63 ///
EndFunction()64 void ARMException::EndFunction() {
65 if (!Asm->MF->getFunction()->needsUnwindTableEntry())
66 Asm->OutStreamer.EmitCantUnwind();
67 else {
68 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
69 Asm->getFunctionNumber()));
70
71 if (EnableARMEHABIDescriptors) {
72 // Map all labels and get rid of any dead landing pads.
73 MMI->TidyLandingPads();
74
75 if (!MMI->getLandingPads().empty()) {
76 // Emit references to personality.
77 if (const Function * Personality =
78 MMI->getPersonalities()[MMI->getPersonalityIndex()]) {
79 MCSymbol *PerSym = Asm->Mang->getSymbol(Personality);
80 Asm->OutStreamer.EmitSymbolAttribute(PerSym, MCSA_Global);
81 Asm->OutStreamer.EmitPersonality(PerSym);
82 }
83
84 // Emit .handlerdata directive.
85 Asm->OutStreamer.EmitHandlerData();
86
87 // Emit actual exception table
88 EmitExceptionTable();
89 }
90 }
91 }
92
93 Asm->OutStreamer.EmitFnEnd();
94 }
95
EmitTypeInfos(unsigned TTypeEncoding)96 void ARMException::EmitTypeInfos(unsigned TTypeEncoding) {
97 const std::vector<const GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
98 const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
99
100 bool VerboseAsm = Asm->OutStreamer.isVerboseAsm();
101
102 int Entry = 0;
103 // Emit the Catch TypeInfos.
104 if (VerboseAsm && !TypeInfos.empty()) {
105 Asm->OutStreamer.AddComment(">> Catch TypeInfos <<");
106 Asm->OutStreamer.AddBlankLine();
107 Entry = TypeInfos.size();
108 }
109
110 for (std::vector<const GlobalVariable *>::const_reverse_iterator
111 I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) {
112 const GlobalVariable *GV = *I;
113 if (VerboseAsm)
114 Asm->OutStreamer.AddComment("TypeInfo " + Twine(Entry--));
115 Asm->EmitTTypeReference(GV, TTypeEncoding);
116 }
117
118 // Emit the Exception Specifications.
119 if (VerboseAsm && !FilterIds.empty()) {
120 Asm->OutStreamer.AddComment(">> Filter TypeInfos <<");
121 Asm->OutStreamer.AddBlankLine();
122 Entry = 0;
123 }
124 for (std::vector<unsigned>::const_iterator
125 I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
126 unsigned TypeID = *I;
127 if (VerboseAsm) {
128 --Entry;
129 if (TypeID != 0)
130 Asm->OutStreamer.AddComment("FilterInfo " + Twine(Entry));
131 }
132
133 Asm->EmitTTypeReference((TypeID == 0 ? 0 : TypeInfos[TypeID - 1]),
134 TTypeEncoding);
135 }
136 }
137