LLVM  15.0.0git
ARMException.cpp
Go to the documentation of this file.
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/Function.h"
18 #include "llvm/MC/MCAsmInfo.h"
19 #include "llvm/MC/MCStreamer.h"
20 using namespace llvm;
21 
23 
24 ARMException::~ARMException() = default;
25 
26 ARMTargetStreamer &ARMException::getTargetStreamer() {
27  MCTargetStreamer &TS = *Asm->OutStreamer->getTargetStreamer();
28  return static_cast<ARMTargetStreamer &>(TS);
29 }
30 
33  getTargetStreamer().emitFnStart();
34  // See if we need call frame info.
36  assert(CFISecType != AsmPrinter::CFISection::EH &&
37  "non-EH CFI not yet supported in prologue with EHABI lowering");
38 
39  if (CFISecType == AsmPrinter::CFISection::Debug) {
40  if (!hasEmittedCFISections) {
42  Asm->OutStreamer->emitCFISections(false, true);
43  hasEmittedCFISections = true;
44  }
45 
46  shouldEmitCFI = true;
47  Asm->OutStreamer->emitCFIStartProc(false);
48  }
49 }
50 
51 /// endFunction - Gather and emit post-function exception information.
52 ///
54  ARMTargetStreamer &ATS = getTargetStreamer();
55  const Function &F = MF->getFunction();
56  const Function *Per = nullptr;
57  if (F.hasPersonalityFn())
58  Per = dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts());
59  bool forceEmitPersonality =
60  F.hasPersonalityFn() && !isNoOpWithoutInvoke(classifyEHPersonality(Per)) &&
61  F.needsUnwindTableEntry();
62  bool shouldEmitPersonality = forceEmitPersonality ||
63  !MF->getLandingPads().empty();
65  !shouldEmitPersonality)
66  ATS.emitCantUnwind();
67  else if (shouldEmitPersonality) {
68  // Emit references to personality.
69  if (Per) {
70  MCSymbol *PerSym = Asm->getSymbol(Per);
71  ATS.emitPersonality(PerSym);
72  }
73 
74  // Emit .handlerdata directive.
75  ATS.emitHandlerData();
76 
77  // Emit actual exception table
79  }
80 
82  ATS.emitFnEnd();
83 }
84 
85 void ARMException::emitTypeInfos(unsigned TTypeEncoding,
86  MCSymbol *TTBaseLabel) {
87  const MachineFunction *MF = Asm->MF;
88  const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();
89  const std::vector<unsigned> &FilterIds = MF->getFilterIds();
90 
91  bool VerboseAsm = Asm->OutStreamer->isVerboseAsm();
92 
93  int Entry = 0;
94  // Emit the Catch TypeInfos.
95  if (VerboseAsm && !TypeInfos.empty()) {
96  Asm->OutStreamer->AddComment(">> Catch TypeInfos <<");
97  Asm->OutStreamer->addBlankLine();
98  Entry = TypeInfos.size();
99  }
100 
101  for (const GlobalValue *GV : reverse(TypeInfos)) {
102  if (VerboseAsm)
103  Asm->OutStreamer->AddComment("TypeInfo " + Twine(Entry--));
104  Asm->emitTTypeReference(GV, TTypeEncoding);
105  }
106 
107  Asm->OutStreamer->emitLabel(TTBaseLabel);
108 
109  // Emit the Exception Specifications.
110  if (VerboseAsm && !FilterIds.empty()) {
111  Asm->OutStreamer->AddComment(">> Filter TypeInfos <<");
112  Asm->OutStreamer->addBlankLine();
113  Entry = 0;
114  }
115  for (std::vector<unsigned>::const_iterator
116  I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
117  unsigned TypeID = *I;
118  if (VerboseAsm) {
119  --Entry;
120  if (TypeID != 0)
121  Asm->OutStreamer->AddComment("FilterInfo " + Twine(Entry));
122  }
123 
124  Asm->emitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]),
125  TTypeEncoding);
126  }
127 }
llvm::ARMTargetStreamer::emitCantUnwind
virtual void emitCantUnwind()
Definition: ARMTargetStreamer.cpp:92
AsmPrinter.h
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:17
llvm::MCSymbol
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
llvm::ARMTargetStreamer::emitFnEnd
virtual void emitFnEnd()
Definition: ARMTargetStreamer.cpp:91
llvm::AsmPrinter::CFISection
CFISection
Definition: AsmPrinter.h:161
llvm::Function
Definition: Function.h:60
llvm::ARMTargetStreamer
Definition: MCStreamer.h:135
llvm::ARMTargetStreamer::emitPersonality
virtual void emitPersonality(const MCSymbol *Personality)
Definition: ARMTargetStreamer.cpp:93
llvm::AsmPrinter::MAI
const MCAsmInfo * MAI
Target Asm Printer information.
Definition: AsmPrinter.h:88
llvm::AsmPrinter::CFISection::Debug
@ Debug
Emit .debug_frame.
llvm::AsmPrinter::getFunctionCFISectionType
CFISection getFunctionCFISectionType(const Function &F) const
Get the CFISection type for a function.
Definition: AsmPrinter.cpp:1239
llvm::reverse
auto reverse(ContainerTy &&C, std::enable_if_t< has_rbegin< ContainerTy >::value > *=nullptr)
Definition: STLExtras.h:380
llvm::ExceptionHandling::ARM
@ ARM
ARM EHABI.
F
#define F(x, y, z)
Definition: MD5.cpp:55
llvm::classifyEHPersonality
EHPersonality classifyEHPersonality(const Value *Pers)
See if the given exception handling personality function is one that we understand.
Definition: EHPersonalities.cpp:22
E
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
llvm::MachineFunction::getFilterIds
const std::vector< unsigned > & getFilterIds() const
Return a reference to the typeids encoding filters used in the current function.
Definition: MachineFunction.h:1217
llvm::AsmPrinter::OutStreamer
std::unique_ptr< MCStreamer > OutStreamer
This is the MCStreamer object for the file we are generating.
Definition: AsmPrinter.h:97
Twine.h
llvm::EHStreamer::emitExceptionTable
MCSymbol * emitExceptionTable()
Emit landing pads and actions.
Definition: EHStreamer.cpp:375
llvm::isNoOpWithoutInvoke
bool isNoOpWithoutInvoke(EHPersonality Pers)
Return true if this personality may be safely removed if there are no invoke instructions remaining i...
Definition: EHPersonalities.h:95
llvm::AsmPrinter::getModuleCFISectionType
CFISection getModuleCFISectionType() const
Get the CFISection type for the module.
Definition: AsmPrinter.h:415
llvm::MCTargetStreamer
Target specific streamer interface.
Definition: MCStreamer.h:93
llvm::ARMException::ARMException
ARMException(AsmPrinter *A)
Definition: ARMException.cpp:22
llvm::DwarfCFIExceptionBase
Definition: DwarfException.h:24
llvm::GlobalValue
Definition: GlobalValue.h:44
llvm::DwarfCFIExceptionBase::hasEmittedCFISections
bool hasEmittedCFISections
Per-module flag to indicate if .cfi_section has beeen emitted.
Definition: DwarfException.h:31
llvm::ARMTargetStreamer::emitHandlerData
virtual void emitHandlerData()
Definition: ARMTargetStreamer.cpp:95
I
#define I(x, y, z)
Definition: MD5.cpp:58
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::AsmPrinter::getSymbol
MCSymbol * getSymbol(const GlobalValue *GV) const
Definition: AsmPrinter.cpp:654
llvm::AsmPrinter::MF
MachineFunction * MF
The current machine function.
Definition: AsmPrinter.h:100
llvm::MachineFunction::getLandingPads
const std::vector< LandingPadInfo > & getLandingPads() const
Return a reference to the landing pad info for the current function.
Definition: MachineFunction.h:1109
llvm::MachineFunction
Definition: MachineFunction.h:257
MCAsmInfo.h
llvm::EHStreamer::Asm
AsmPrinter * Asm
Target of directive emission.
Definition: EHStreamer.h:33
llvm::Twine
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:83
llvm::ARMException::endFunction
void endFunction(const MachineFunction *) override
Gather and emit post-function exception information.
Definition: ARMException.cpp:53
llvm::MachineFunction::getFunction
Function & getFunction()
Return the LLVM function that this machine code represents.
Definition: MachineFunction.h:622
llvm::DwarfCFIExceptionBase::shouldEmitCFI
bool shouldEmitCFI
Per-function flag to indicate if frame CFI info should be emitted.
Definition: DwarfException.h:29
llvm::ARMException::~ARMException
~ARMException() override
Function.h
llvm::Function::needsUnwindTableEntry
bool needsUnwindTableEntry() const
True if this function needs an unwind table.
Definition: Function.h:639
llvm::ARMException::beginFunction
void beginFunction(const MachineFunction *MF) override
Gather pre-function exception information.
Definition: ARMException.cpp:31
llvm::AsmPrinter
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:82
llvm::ARMTargetStreamer::emitFnStart
virtual void emitFnStart()
Definition: ARMTargetStreamer.cpp:90
llvm::MCAsmInfo::getExceptionHandlingType
ExceptionHandling getExceptionHandlingType() const
Definition: MCAsmInfo.h:777
llvm::AsmPrinter::emitTTypeReference
virtual void emitTTypeReference(const GlobalValue *GV, unsigned Encoding)
Emit reference to a ttype global with a specified encoding.
Definition: AsmPrinterDwarf.cpp:143
MCStreamer.h
DwarfException.h
llvm::MachineFunction::getTypeInfos
const std::vector< const GlobalValue * > & getTypeInfos() const
Return a reference to the C++ typeinfo for the current function.
Definition: MachineFunction.h:1211
llvm::Type::TypeID
TypeID
Definitions of all of the base types for the Type system.
Definition: Type.h:54
MachineFunction.h
llvm::AsmPrinter::CFISection::EH
@ EH
Emit .eh_frame.