LLVM  9.0.0svn
ARMException.cpp
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1 //===-- CodeGen/AsmPrinter/ARMException.cpp - ARM EHABI Exception Impl ----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains support for writing DWARF exception info into asm files.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "DwarfException.h"
14 #include "llvm/ADT/Twine.h"
17 #include "llvm/IR/DataLayout.h"
18 #include "llvm/IR/Mangler.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/MC/MCAsmInfo.h"
21 #include "llvm/MC/MCExpr.h"
22 #include "llvm/MC/MCSection.h"
23 #include "llvm/MC/MCStreamer.h"
24 #include "llvm/MC/MCSymbol.h"
27 using namespace llvm;
28 
30 
32 
33 ARMTargetStreamer &ARMException::getTargetStreamer() {
34  MCTargetStreamer &TS = *Asm->OutStreamer->getTargetStreamer();
35  return static_cast<ARMTargetStreamer &>(TS);
36 }
37 
40  getTargetStreamer().emitFnStart();
41  // See if we need call frame info.
43  assert(MoveType != AsmPrinter::CFI_M_EH &&
44  "non-EH CFI not yet supported in prologue with EHABI lowering");
45 
46  if (MoveType == AsmPrinter::CFI_M_Debug) {
47  if (!hasEmittedCFISections) {
49  Asm->OutStreamer->EmitCFISections(false, true);
50  hasEmittedCFISections = true;
51  }
52 
53  shouldEmitCFI = true;
54  Asm->OutStreamer->EmitCFIStartProc(false);
55  }
56 }
57 
58 /// endFunction - Gather and emit post-function exception information.
59 ///
61  ARMTargetStreamer &ATS = getTargetStreamer();
62  const Function &F = MF->getFunction();
63  const Function *Per = nullptr;
64  if (F.hasPersonalityFn())
65  Per = dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts());
66  bool forceEmitPersonality =
69  bool shouldEmitPersonality = forceEmitPersonality ||
70  !MF->getLandingPads().empty();
72  !shouldEmitPersonality)
73  ATS.emitCantUnwind();
74  else if (shouldEmitPersonality) {
75  // Emit references to personality.
76  if (Per) {
77  MCSymbol *PerSym = Asm->getSymbol(Per);
78  Asm->OutStreamer->EmitSymbolAttribute(PerSym, MCSA_Global);
79  ATS.emitPersonality(PerSym);
80  }
81 
82  // Emit .handlerdata directive.
83  ATS.emitHandlerData();
84 
85  // Emit actual exception table
87  }
88 
90  ATS.emitFnEnd();
91 }
92 
93 void ARMException::emitTypeInfos(unsigned TTypeEncoding,
94  MCSymbol *TTBaseLabel) {
95  const MachineFunction *MF = Asm->MF;
96  const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();
97  const std::vector<unsigned> &FilterIds = MF->getFilterIds();
98 
99  bool VerboseAsm = Asm->OutStreamer->isVerboseAsm();
100 
101  int Entry = 0;
102  // Emit the Catch TypeInfos.
103  if (VerboseAsm && !TypeInfos.empty()) {
104  Asm->OutStreamer->AddComment(">> Catch TypeInfos <<");
105  Asm->OutStreamer->AddBlankLine();
106  Entry = TypeInfos.size();
107  }
108 
109  for (const GlobalValue *GV : reverse(TypeInfos)) {
110  if (VerboseAsm)
111  Asm->OutStreamer->AddComment("TypeInfo " + Twine(Entry--));
112  Asm->EmitTTypeReference(GV, TTypeEncoding);
113  }
114 
115  Asm->OutStreamer->EmitLabel(TTBaseLabel);
116 
117  // Emit the Exception Specifications.
118  if (VerboseAsm && !FilterIds.empty()) {
119  Asm->OutStreamer->AddComment(">> Filter TypeInfos <<");
120  Asm->OutStreamer->AddBlankLine();
121  Entry = 0;
122  }
123  for (std::vector<unsigned>::const_iterator
124  I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
125  unsigned TypeID = *I;
126  if (VerboseAsm) {
127  --Entry;
128  if (TypeID != 0)
129  Asm->OutStreamer->AddComment("FilterInfo " + Twine(Entry));
130  }
131 
132  Asm->EmitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]),
133  TTypeEncoding);
134  }
135 }
std::unique_ptr< MCStreamer > OutStreamer
This is the MCStreamer object for the file we are generating.
Definition: AsmPrinter.h:93
This class represents lattice values for constants.
Definition: AllocatorList.h:23
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
bool needsOnlyDebugCFIMoves() const
Returns false if needsCFIMoves() == CFI_M_EH for any function in the module.
Definition: AsmPrinter.h:323
CFIMoveType needsCFIMoves() const
Definition: AsmPrinter.cpp:912
Target specific streamer interface.
Definition: MCStreamer.h:83
bool shouldEmitCFI
Per-function flag to indicate if frame CFI info should be emitted.
F(f)
MachineFunction * MF
The current machine function.
Definition: AsmPrinter.h:96
setjmp/longjmp based exceptions
virtual void emitPersonality(const MCSymbol *Personality)
const std::vector< unsigned > & getFilterIds() const
Return a reference to the typeids encoding filters used in the current function.
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:80
TypeID
Definitions of all of the base types for the Type system.
Definition: Type.h:54
auto reverse(ContainerTy &&C, typename std::enable_if< has_rbegin< ContainerTy >::value >::type *=nullptr) -> decltype(make_range(C.rbegin(), C.rend()))
Definition: STLExtras.h:266
bool hasPersonalityFn() const
Check whether this function has a personality function.
Definition: Function.h:701
void endFunction(const MachineFunction *) override
Gather and emit post-function exception information.
void beginFunction(const MachineFunction *MF) override
Gather pre-function exception information.
const MCAsmInfo * MAI
Target Asm Printer information.
Definition: AsmPrinter.h:84
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
EHPersonality classifyEHPersonality(const Value *Pers)
See if the given exception handling personality function is one that we understand.
const Constant * stripPointerCasts() const
Definition: Constant.h:173
AsmPrinter * Asm
Target of directive emission.
Definition: EHStreamer.h:33
bool hasEmittedCFISections
Per-module flag to indicate if .cfi_section has beeen emitted.
const std::vector< LandingPadInfo > & getLandingPads() const
Return a reference to the landing pad info for the current function.
MCSymbol * getSymbol(const GlobalValue *GV) const
Definition: AsmPrinter.cpp:430
Module.h This file contains the declarations for the Module class.
void EmitTTypeReference(const GlobalValue *GV, unsigned Encoding) const
Emit reference to a ttype global with a specified encoding.
const Function & getFunction() const
Return the LLVM function that this machine code represents.
bool needsUnwindTableEntry() const
True if this function needs an unwind table.
Definition: Function.h:572
.type _foo,
Definition: MCDirectives.h:30
#define I(x, y, z)
Definition: MD5.cpp:58
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
MCSymbol * emitExceptionTable()
Emit landing pads and actions.
Definition: EHStreamer.cpp:349
Constant * getPersonalityFn() const
Get the personality function associated with this function.
Definition: Function.cpp:1302
ExceptionHandling getExceptionHandlingType() const
Definition: MCAsmInfo.h:569
const std::vector< const GlobalValue * > & getTypeInfos() const
Return a reference to the C++ typeinfo for the current function.
bool isNoOpWithoutInvoke(EHPersonality Pers)
Return true if this personality may be safely removed if there are no invoke instructions remaining i...
ARMException(AsmPrinter *A)
~ARMException() override