bool PNaClSjLjEH::runOnModule(Module &M) {
Type *JmpBufTy = ArrayType::get(Type::getInt8Ty(M.getContext()),
kPNaClJmpBufSize);
// Define "struct ExceptionFrame".
StructType *ExceptionFrameTy = StructType::create(M.getContext(),
"ExceptionFrame");
Type *ExceptionFrameFields[] = {
JmpBufTy, // jmp_buf
ExceptionFrameTy->getPointerTo(), // struct ExceptionFrame *next
Type::getInt32Ty(M.getContext()) // Exception info (clause list ID)
};
ExceptionFrameTy->setBody(ExceptionFrameFields);
ExceptionInfoWriter ExcInfoWriter(&M.getContext());
for (Module::iterator Func = M.begin(), E = M.end(); Func != E; ++Func) {
FuncRewriter Rewriter(ExceptionFrameTy, &ExcInfoWriter, Func);
Rewriter.expandFunc();
}
ExcInfoWriter.defineGlobalVariables(&M);
return true;
}
Function *GCOVProfiler::insertCounterWriteout(
ArrayRef<std::pair<GlobalVariable *, MDNode *> > CountersBySP) {
FunctionType *WriteoutFTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
Function *WriteoutF = M->getFunction("__llvm_gcov_writeout");
if (!WriteoutF)
WriteoutF = Function::Create(WriteoutFTy, GlobalValue::InternalLinkage,
"__llvm_gcov_writeout", M);
WriteoutF->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
WriteoutF->addFnAttr(Attribute::NoInline);
if (Options.NoRedZone)
WriteoutF->addFnAttr(Attribute::NoRedZone);
BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", WriteoutF);
IRBuilder<> Builder(BB);
Constant *StartFile = getStartFileFunc();
Constant *EmitFunction = getEmitFunctionFunc();
Constant *EmitArcs = getEmitArcsFunc();
Constant *SummaryInfo = getSummaryInfoFunc();
Constant *EndFile = getEndFileFunc();
NamedMDNode *CUNodes = M->getNamedMetadata("llvm.dbg.cu");
if (!CUNodes) {
Builder.CreateRetVoid();
return WriteoutF;
}
// Collect the relevant data into a large constant data structure that we can
// walk to write out everything.
StructType *StartFileCallArgsTy = StructType::create(
{Builder.getInt8PtrTy(), Builder.getInt8PtrTy(), Builder.getInt32Ty()});
StructType *EmitFunctionCallArgsTy = StructType::create(
{Builder.getInt32Ty(), Builder.getInt8PtrTy(), Builder.getInt32Ty(),
Builder.getInt8Ty(), Builder.getInt32Ty()});
StructType *EmitArcsCallArgsTy = StructType::create(
{Builder.getInt32Ty(), Builder.getInt64Ty()->getPointerTo()});
StructType *FileInfoTy =
StructType::create({StartFileCallArgsTy, Builder.getInt32Ty(),
EmitFunctionCallArgsTy->getPointerTo(),
EmitArcsCallArgsTy->getPointerTo()});
Constant *Zero32 = Builder.getInt32(0);
// Build an explicit array of two zeros for use in ConstantExpr GEP building.
Constant *TwoZero32s[] = {Zero32, Zero32};
SmallVector<Constant *, 8> FileInfos;
for (int i : llvm::seq<int>(0, CUNodes->getNumOperands())) {
auto *CU = cast<DICompileUnit>(CUNodes->getOperand(i));
// Skip module skeleton (and module) CUs.
if (CU->getDWOId())
continue;
std::string FilenameGcda = mangleName(CU, GCovFileType::GCDA);
uint32_t CfgChecksum = FileChecksums.empty() ? 0 : FileChecksums[i];
auto *StartFileCallArgs = ConstantStruct::get(
StartFileCallArgsTy, {Builder.CreateGlobalStringPtr(FilenameGcda),
Builder.CreateGlobalStringPtr(ReversedVersion),
Builder.getInt32(CfgChecksum)});
SmallVector<Constant *, 8> EmitFunctionCallArgsArray;
SmallVector<Constant *, 8> EmitArcsCallArgsArray;
for (int j : llvm::seq<int>(0, CountersBySP.size())) {
auto *SP = cast_or_null<DISubprogram>(CountersBySP[j].second);
uint32_t FuncChecksum = Funcs.empty() ? 0 : Funcs[j]->getFuncChecksum();
EmitFunctionCallArgsArray.push_back(ConstantStruct::get(
EmitFunctionCallArgsTy,
{Builder.getInt32(j),
Options.FunctionNamesInData
? Builder.CreateGlobalStringPtr(getFunctionName(SP))
: Constant::getNullValue(Builder.getInt8PtrTy()),
Builder.getInt32(FuncChecksum),
Builder.getInt8(Options.UseCfgChecksum),
Builder.getInt32(CfgChecksum)}));
GlobalVariable *GV = CountersBySP[j].first;
unsigned Arcs = cast<ArrayType>(GV->getValueType())->getNumElements();
EmitArcsCallArgsArray.push_back(ConstantStruct::get(
EmitArcsCallArgsTy,
{Builder.getInt32(Arcs), ConstantExpr::getInBoundsGetElementPtr(
GV->getValueType(), GV, TwoZero32s)}));
}
// Create global arrays for the two emit calls.
int CountersSize = CountersBySP.size();
assert(CountersSize == (int)EmitFunctionCallArgsArray.size() &&
"Mismatched array size!");
assert(CountersSize == (int)EmitArcsCallArgsArray.size() &&
"Mismatched array size!");
auto *EmitFunctionCallArgsArrayTy =
ArrayType::get(EmitFunctionCallArgsTy, CountersSize);
auto *EmitFunctionCallArgsArrayGV = new GlobalVariable(
*M, EmitFunctionCallArgsArrayTy, /*isConstant*/ true,
GlobalValue::InternalLinkage,
ConstantArray::get(EmitFunctionCallArgsArrayTy,
EmitFunctionCallArgsArray),
Twine("__llvm_internal_gcov_emit_function_args.") + Twine(i));
auto *EmitArcsCallArgsArrayTy =
ArrayType::get(EmitArcsCallArgsTy, CountersSize);
EmitFunctionCallArgsArrayGV->setUnnamedAddr(
GlobalValue::UnnamedAddr::Global);
auto *EmitArcsCallArgsArrayGV = new GlobalVariable(
*M, EmitArcsCallArgsArrayTy, /*isConstant*/ true,
GlobalValue::InternalLinkage,
ConstantArray::get(EmitArcsCallArgsArrayTy, EmitArcsCallArgsArray),
Twine("__llvm_internal_gcov_emit_arcs_args.") + Twine(i));
EmitArcsCallArgsArrayGV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
FileInfos.push_back(ConstantStruct::get(
FileInfoTy,
{StartFileCallArgs, Builder.getInt32(CountersSize),
ConstantExpr::getInBoundsGetElementPtr(EmitFunctionCallArgsArrayTy,
EmitFunctionCallArgsArrayGV,
TwoZero32s),
ConstantExpr::getInBoundsGetElementPtr(
EmitArcsCallArgsArrayTy, EmitArcsCallArgsArrayGV, TwoZero32s)}));
}
// If we didn't find anything to actually emit, bail on out.
if (FileInfos.empty()) {
Builder.CreateRetVoid();
return WriteoutF;
}
// To simplify code, we cap the number of file infos we write out to fit
// easily in a 32-bit signed integer. This gives consistent behavior between
// 32-bit and 64-bit systems without requiring (potentially very slow) 64-bit
// operations on 32-bit systems. It also seems unreasonable to try to handle
// more than 2 billion files.
if ((int64_t)FileInfos.size() > (int64_t)INT_MAX)
FileInfos.resize(INT_MAX);
// Create a global for the entire data structure so we can walk it more
// easily.
auto *FileInfoArrayTy = ArrayType::get(FileInfoTy, FileInfos.size());
auto *FileInfoArrayGV = new GlobalVariable(
*M, FileInfoArrayTy, /*isConstant*/ true, GlobalValue::InternalLinkage,
ConstantArray::get(FileInfoArrayTy, FileInfos),
"__llvm_internal_gcov_emit_file_info");
FileInfoArrayGV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
// Create the CFG for walking this data structure.
auto *FileLoopHeader =
BasicBlock::Create(*Ctx, "file.loop.header", WriteoutF);
auto *CounterLoopHeader =
BasicBlock::Create(*Ctx, "counter.loop.header", WriteoutF);
auto *FileLoopLatch = BasicBlock::Create(*Ctx, "file.loop.latch", WriteoutF);
auto *ExitBB = BasicBlock::Create(*Ctx, "exit", WriteoutF);
// We always have at least one file, so just branch to the header.
Builder.CreateBr(FileLoopHeader);
// The index into the files structure is our loop induction variable.
Builder.SetInsertPoint(FileLoopHeader);
PHINode *IV =
Builder.CreatePHI(Builder.getInt32Ty(), /*NumReservedValues*/ 2);
IV->addIncoming(Builder.getInt32(0), BB);
auto *FileInfoPtr =
Builder.CreateInBoundsGEP(FileInfoArrayGV, {Builder.getInt32(0), IV});
auto *StartFileCallArgsPtr = Builder.CreateStructGEP(FileInfoPtr, 0);
Builder.CreateCall(
StartFile,
{Builder.CreateLoad(Builder.CreateStructGEP(StartFileCallArgsPtr, 0)),
Builder.CreateLoad(Builder.CreateStructGEP(StartFileCallArgsPtr, 1)),
Builder.CreateLoad(Builder.CreateStructGEP(StartFileCallArgsPtr, 2))});
auto *NumCounters =
Builder.CreateLoad(Builder.CreateStructGEP(FileInfoPtr, 1));
auto *EmitFunctionCallArgsArray =
Builder.CreateLoad(Builder.CreateStructGEP(FileInfoPtr, 2));
auto *EmitArcsCallArgsArray =
Builder.CreateLoad(Builder.CreateStructGEP(FileInfoPtr, 3));
auto *EnterCounterLoopCond =
Builder.CreateICmpSLT(Builder.getInt32(0), NumCounters);
Builder.CreateCondBr(EnterCounterLoopCond, CounterLoopHeader, FileLoopLatch);
Builder.SetInsertPoint(CounterLoopHeader);
auto *JV = Builder.CreatePHI(Builder.getInt32Ty(), /*NumReservedValues*/ 2);
JV->addIncoming(Builder.getInt32(0), FileLoopHeader);
auto *EmitFunctionCallArgsPtr =
Builder.CreateInBoundsGEP(EmitFunctionCallArgsArray, {JV});
Builder.CreateCall(
EmitFunction,
{Builder.CreateLoad(Builder.CreateStructGEP(EmitFunctionCallArgsPtr, 0)),
Builder.CreateLoad(Builder.CreateStructGEP(EmitFunctionCallArgsPtr, 1)),
Builder.CreateLoad(Builder.CreateStructGEP(EmitFunctionCallArgsPtr, 2)),
Builder.CreateLoad(Builder.CreateStructGEP(EmitFunctionCallArgsPtr, 3)),
Builder.CreateLoad(
Builder.CreateStructGEP(EmitFunctionCallArgsPtr, 4))});
auto *EmitArcsCallArgsPtr =
Builder.CreateInBoundsGEP(EmitArcsCallArgsArray, {JV});
Builder.CreateCall(
EmitArcs,
{Builder.CreateLoad(Builder.CreateStructGEP(EmitArcsCallArgsPtr, 0)),
Builder.CreateLoad(Builder.CreateStructGEP(EmitArcsCallArgsPtr, 1))});
auto *NextJV = Builder.CreateAdd(JV, Builder.getInt32(1));
auto *CounterLoopCond = Builder.CreateICmpSLT(NextJV, NumCounters);
Builder.CreateCondBr(CounterLoopCond, CounterLoopHeader, FileLoopLatch);
JV->addIncoming(NextJV, CounterLoopHeader);
Builder.SetInsertPoint(FileLoopLatch);
Builder.CreateCall(SummaryInfo, {});
Builder.CreateCall(EndFile, {});
auto *NextIV = Builder.CreateAdd(IV, Builder.getInt32(1));
auto *FileLoopCond =
Builder.CreateICmpSLT(NextIV, Builder.getInt32(FileInfos.size()));
Builder.CreateCondBr(FileLoopCond, FileLoopHeader, ExitBB);
IV->addIncoming(NextIV, FileLoopLatch);
Builder.SetInsertPoint(ExitBB);
Builder.CreateRetVoid();
return WriteoutF;
}
static bool ExpandVarArgCall(Module *M, InstType *Call, DataLayout *DL) {
FunctionType *FuncType = cast<FunctionType>(
Call->getCalledValue()->getType()->getPointerElementType());
if (!FuncType->isFunctionVarArg())
return false;
if (auto *F = dyn_cast<Function>(Call->getCalledValue()))
if (isEmscriptenJSArgsFunc(M, F->getName()))
return false;
Function *F = Call->getParent()->getParent();
LLVMContext &Ctx = M->getContext();
SmallVector<AttributeSet, 8> Attrs;
Attrs.push_back(Call->getAttributes().getFnAttributes());
Attrs.push_back(Call->getAttributes().getRetAttributes());
// Split argument list into fixed and variable arguments.
SmallVector<Value *, 8> FixedArgs;
SmallVector<Value *, 8> VarArgs;
SmallVector<Type *, 8> VarArgsTypes;
for (unsigned I = 0, E = FuncType->getNumParams(); I < E; ++I) {
FixedArgs.push_back(Call->getArgOperand(I));
// AttributeSets use 1-based indexing.
Attrs.push_back(Call->getAttributes().getParamAttributes(I + 1));
}
for (unsigned I = FuncType->getNumParams(), E = Call->getNumArgOperands();
I < E; ++I) {
Value *ArgVal = Call->getArgOperand(I);
VarArgs.push_back(ArgVal);
bool isByVal = Call->getAttributes().hasAttribute(I + 1, Attribute::ByVal);
// For "byval" arguments we must dereference the pointer.
VarArgsTypes.push_back(isByVal ? ArgVal->getType()->getPointerElementType()
: ArgVal->getType());
}
if (VarArgsTypes.size() == 0) {
// Some buggy code (e.g. 176.gcc in Spec2k) uses va_arg on an
// empty argument list, which gives undefined behaviour in C. To
// work around such programs, we create a dummy varargs buffer on
// the stack even though there are no arguments to put in it.
// This allows va_arg to read an undefined value from the stack
// rather than crashing by reading from an uninitialized pointer.
// An alternative would be to pass a null pointer to catch the
// invalid use of va_arg.
VarArgsTypes.push_back(Type::getInt32Ty(Ctx));
}
// Create struct type for packing variable arguments into.
StructType *VarArgsTy = StructType::get(Ctx, VarArgsTypes);
// Allocate space for the variable argument buffer. Do this at the
// start of the function so that we don't leak space if the function
// is called in a loop.
IRBuilder<> IRB(F->getEntryBlock().getFirstInsertionPt());
auto *Buf = IRB.CreateAlloca(VarArgsTy, nullptr, "vararg_buffer");
// Call llvm.lifetime.start/end intrinsics to indicate that Buf is
// only used for the duration of the function call, so that the
// stack space can be reused elsewhere.
auto LifetimeStart = Intrinsic::getDeclaration(M, Intrinsic::lifetime_start);
auto LifetimeEnd = Intrinsic::getDeclaration(M, Intrinsic::lifetime_end);
auto *I8Ptr = Type::getInt8Ty(Ctx)->getPointerTo();
auto *BufPtr = IRB.CreateBitCast(Buf, I8Ptr, "vararg_lifetime_bitcast");
auto *BufSize =
ConstantInt::get(Ctx, APInt(64, DL->getTypeAllocSize(VarArgsTy)));
IRB.CreateCall2(LifetimeStart, BufSize, BufPtr);
// Copy variable arguments into buffer.
int Index = 0;
IRB.SetInsertPoint(Call);
for (Value *Arg : VarArgs) {
Value *Indexes[] = {ConstantInt::get(Ctx, APInt(32, 0)),
ConstantInt::get(Ctx, APInt(32, Index))};
Value *Ptr = IRB.CreateInBoundsGEP(Buf, Indexes, "vararg_ptr");
bool isByVal = Call->getAttributes().hasAttribute(
FuncType->getNumParams() + Index + 1, Attribute::ByVal);
if (isByVal)
IRB.CreateMemCpy(Ptr, Arg, DL->getTypeAllocSize(
Arg->getType()->getPointerElementType()),
/*Align=*/1);
else
IRB.CreateStore(Arg, Ptr);
++Index;
}
// Cast function to new type to add our extra pointer argument.
SmallVector<Type *, 8> ArgTypes(FuncType->param_begin(),
FuncType->param_end());
ArgTypes.push_back(VarArgsTy->getPointerTo());
FunctionType *NFTy = FunctionType::get(FuncType->getReturnType(), ArgTypes,
/*isVarArg=*/false);
Value *CastFunc = IRB.CreateBitCast(Call->getCalledValue(),
NFTy->getPointerTo(), "vararg_func");
// Create the converted function call.
FixedArgs.push_back(Buf);
Instruction *NewCall;
if (auto *C = dyn_cast<CallInst>(Call)) {
auto *N = IRB.CreateCall(CastFunc, FixedArgs);
N->setAttributes(AttributeSet::get(Ctx, Attrs));
NewCall = N;
IRB.CreateCall2(LifetimeEnd, BufSize, BufPtr);
} else if (auto *C = dyn_cast<InvokeInst>(Call)) {
auto *N = IRB.CreateInvoke(CastFunc, C->getNormalDest(), C->getUnwindDest(),
FixedArgs, C->getName());
N->setAttributes(AttributeSet::get(Ctx, Attrs));
(IRBuilder<>(C->getNormalDest()->getFirstInsertionPt()))
.CreateCall2(LifetimeEnd, BufSize, BufPtr);
(IRBuilder<>(C->getUnwindDest()->getFirstInsertionPt()))
.CreateCall2(LifetimeEnd, BufSize, BufPtr);
NewCall = N;
} else {
llvm_unreachable("not a call/invoke");
}
NewCall->takeName(Call);
Call->replaceAllUsesWith(NewCall);
Call->eraseFromParent();
return true;
}
int main() {
InitializeNativeTarget();
LLVMContext& Context = getGlobalContext();
Module *M = new Module("test C++ exception handling ", Context);
StructType* MyStructType = StructType::create(Context, "struct.MyStruct");
Type* MyStructFields[] = {
Type::getInt32Ty(Context),
Type::getInt32Ty(Context)
};
MyStructType->setBody(MyStructFields);
GlobalValue* throwFunc = cast<GlobalValue>(M->getOrInsertFunction("throwMyStruct", Type::getVoidTy(Context), NULL));
GlobalValue* MyStructTypeInfo = cast<GlobalValue>(M->getOrInsertGlobal("MyStructTypeInfo", Type::getInt8Ty(Context)));
Function* gxx_personality = Function::Create(FunctionType::get(Type::getInt32Ty(Context), true), Function::ExternalLinkage, "__gxx_personality_v0", M);
Function* begin_catch = Function::Create(FunctionType::get(Type::getInt8PtrTy(Context), Type::getInt8PtrTy(Context), false), Function::ExternalLinkage, "__cxa_begin_catch", M);
Function* end_catch = Function::Create(FunctionType::get(Type::getVoidTy(Context), false), Function::ExternalLinkage, "__cxa_end_catch", M);
Function* testExceptions = cast<Function>(M->getOrInsertFunction("testExceptions", Type::getInt32Ty(Context), NULL));
BasicBlock* entryBB = BasicBlock::Create(Context, "", testExceptions);
BasicBlock* landPadBB = BasicBlock::Create(Context, "landPad", testExceptions);
BasicBlock* noErrorBB = BasicBlock::Create(Context, "noError", testExceptions);
IRBuilder<> builder(entryBB);
Value* invokeThrow = builder.CreateInvoke(throwFunc, noErrorBB, landPadBB);
builder.SetInsertPoint(noErrorBB);
builder.CreateRet( builder.getInt32(666) ); // should never happen
//writing landingpad! <<<<<<<
builder.SetInsertPoint(landPadBB);
Value* gxx_personality_i8 = builder.CreateBitCast(gxx_personality, Type::getInt8PtrTy(Context));
Type* caughtType = StructType::get(builder.getInt8PtrTy(), builder.getInt32Ty(), NULL);
LandingPadInst* caughtResult = builder.CreateLandingPad(caughtType, gxx_personality_i8, 1);
// we can catch any C++ exception we want
// but now we are catching MyStruct
caughtResult->addClause(MyStructTypeInfo);
//we are sure to catch MyStruct so no other checks are needed
//if throwMyStruct() throws anything but MyStruct it won't pass to the current landingpad BB
Value* thrownExctn = builder.CreateExtractValue(caughtResult, 0);
Value* thrownObject = builder.CreateCall(begin_catch, thrownExctn);
Value* object = builder.CreateBitCast(thrownObject, MyStructType->getPointerTo());
Value* resultPtr = builder.CreateStructGEP(object, 1);
Value* result = builder.CreateLoad(resultPtr);
builder.CreateCall(end_catch);
builder.CreateRet( result ); // << z.y
TargetOptions Opts;
Opts.JITExceptionHandling = true; // DO NOT FORGET THIS OPTION !!!!!!11
ExecutionEngine* EE = EngineBuilder(M)
.setEngineKind(EngineKind::JIT)
.setTargetOptions(Opts)
.create();
EE->addGlobalMapping(throwFunc, reinterpret_cast<void*>(&throwMyStruct));
EE->addGlobalMapping(MyStructTypeInfo, MyStruct::getTypeInfo());
verifyFunction(*testExceptions);
outs() << *testExceptions;
std::vector<GenericValue> noArgs;
GenericValue gv = EE->runFunction(testExceptions, noArgs);
outs() << "\ntestExceptions result: " << gv.IntVal << "\n";
delete EE;
llvm_shutdown();
return 0;
}
