llvm-project/llvm/lib/CodeGen/AsmPrinter/ARMException.cpp

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4.4 KiB
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//===-- CodeGen/AsmPrinter/ARMException.cpp - ARM EHABI Exception Impl ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains support for writing DWARF exception info into asm files.
//
//===----------------------------------------------------------------------===//
#include "DwarfException.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
ARMException::ARMException(AsmPrinter *A) : DwarfCFIExceptionBase(A) {}
ARMException::~ARMException() {}
ARMTargetStreamer &ARMException::getTargetStreamer() {
MCTargetStreamer &TS = *Asm->OutStreamer->getTargetStreamer();
return static_cast<ARMTargetStreamer &>(TS);
}
void ARMException::beginFunction(const MachineFunction *MF) {
if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
getTargetStreamer().emitFnStart();
// See if we need call frame info.
AsmPrinter::CFIMoveType MoveType = Asm->needsCFIMoves();
assert(MoveType != AsmPrinter::CFI_M_EH &&
"non-EH CFI not yet supported in prologue with EHABI lowering");
if (MoveType == AsmPrinter::CFI_M_Debug) {
if (!hasEmittedCFISections) {
if (Asm->needsOnlyDebugCFIMoves())
Asm->OutStreamer->EmitCFISections(false, true);
hasEmittedCFISections = true;
}
shouldEmitCFI = true;
Asm->OutStreamer->EmitCFIStartProc(false);
}
}
/// endFunction - Gather and emit post-function exception information.
///
void ARMException::endFunction(const MachineFunction *MF) {
ARMTargetStreamer &ATS = getTargetStreamer();
const Function &F = MF->getFunction();
const Function *Per = nullptr;
if (F.hasPersonalityFn())
Per = dyn_cast<Function>(F.getPersonalityFn()->stripPointerCasts());
bool forceEmitPersonality =
F.hasPersonalityFn() && !isNoOpWithoutInvoke(classifyEHPersonality(Per)) &&
F.needsUnwindTableEntry();
bool shouldEmitPersonality = forceEmitPersonality ||
!MF->getLandingPads().empty();
if (!Asm->MF->getFunction().needsUnwindTableEntry() &&
!shouldEmitPersonality)
ATS.emitCantUnwind();
else if (shouldEmitPersonality) {
// Emit references to personality.
if (Per) {
MCSymbol *PerSym = Asm->getSymbol(Per);
Asm->OutStreamer->EmitSymbolAttribute(PerSym, MCSA_Global);
ATS.emitPersonality(PerSym);
}
// Emit .handlerdata directive.
ATS.emitHandlerData();
// Emit actual exception table
emitExceptionTable();
}
if (Asm->MAI->getExceptionHandlingType() == ExceptionHandling::ARM)
ATS.emitFnEnd();
}
void ARMException::emitTypeInfos(unsigned TTypeEncoding,
MCSymbol *TTBaseLabel) {
const MachineFunction *MF = Asm->MF;
const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();
const std::vector<unsigned> &FilterIds = MF->getFilterIds();
bool VerboseAsm = Asm->OutStreamer->isVerboseAsm();
int Entry = 0;
// Emit the Catch TypeInfos.
if (VerboseAsm && !TypeInfos.empty()) {
Asm->OutStreamer->AddComment(">> Catch TypeInfos <<");
Asm->OutStreamer->AddBlankLine();
Entry = TypeInfos.size();
}
for (const GlobalValue *GV : reverse(TypeInfos)) {
if (VerboseAsm)
Asm->OutStreamer->AddComment("TypeInfo " + Twine(Entry--));
Asm->EmitTTypeReference(GV, TTypeEncoding);
}
Asm->OutStreamer->EmitLabel(TTBaseLabel);
// Emit the Exception Specifications.
if (VerboseAsm && !FilterIds.empty()) {
Asm->OutStreamer->AddComment(">> Filter TypeInfos <<");
Asm->OutStreamer->AddBlankLine();
Entry = 0;
}
for (std::vector<unsigned>::const_iterator
I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
unsigned TypeID = *I;
if (VerboseAsm) {
--Entry;
if (TypeID != 0)
Asm->OutStreamer->AddComment("FilterInfo " + Twine(Entry));
}
Asm->EmitTTypeReference((TypeID == 0 ? nullptr : TypeInfos[TypeID - 1]),
TTypeEncoding);
}
}