llvm.global_[cd]tor is defined to be either external, or appending with an array

of { i32, void ()* }. Teach the verifier to verify that, deleting copies of
checks strewn about.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129128 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky 2011-04-08 07:30:21 +00:00
parent dd099e1e55
commit 2c44a80d99
4 changed files with 32 additions and 36 deletions

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@ -660,19 +660,17 @@ bool ELFWriter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
/// EmitXXStructorList - Emit the ctor or dtor list. This just emits out the
/// function pointers, ignoring the init priority.
void ELFWriter::EmitXXStructorList(Constant *List, ELFSection &Xtor) {
// Should be an array of '{ int, void ()* }' structs. The first value is the
// Should be an array of '{ i32, void ()* }' structs. The first value is the
// init priority, which we ignore.
if (!isa<ConstantArray>(List)) return;
ConstantArray *InitList = cast<ConstantArray>(List);
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
if (CS->getOperand(1)->isNullValue())
return; // Found a null terminator, exit printing.
// Emit the function pointer.
EmitGlobalConstant(CS->getOperand(1), Xtor);
}
if (CS->getOperand(1)->isNullValue())
return; // Found a null terminator, exit printing.
// Emit the function pointer.
EmitGlobalConstant(CS->getOperand(1), Xtor);
}
}
bool ELFWriter::runOnMachineFunction(MachineFunction &MF) {

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@ -313,13 +313,9 @@ void ExecutionEngine::runStaticConstructorsDestructors(Module *module,
// Should be an array of '{ i32, void ()* }' structs. The first value is
// the init priority, which we ignore.
ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (!InitList) return;
ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
ConstantStruct *CS =
dyn_cast<ConstantStruct>(InitList->getOperand(i));
if (!CS) continue;
if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
Constant *FP = CS->getOperand(1);
if (FP->isNullValue())

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@ -1944,35 +1944,20 @@ bool GlobalOpt::OptimizeGlobalVars(Module &M) {
return Changed;
}
/// FindGlobalCtors - Find the llvm.globalctors list, verifying that all
/// FindGlobalCtors - Find the llvm.global_ctors list, verifying that all
/// initializers have an init priority of 65535.
GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
if (GV == 0) return 0;
// Found it, verify it's an array of { int, void()* }.
const ArrayType *ATy =dyn_cast<ArrayType>(GV->getType()->getElementType());
if (!ATy) return 0;
const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
if (!STy || STy->getNumElements() != 2 ||
!STy->getElementType(0)->isIntegerTy(32)) return 0;
const PointerType *PFTy = dyn_cast<PointerType>(STy->getElementType(1));
if (!PFTy) return 0;
const FunctionType *FTy = dyn_cast<FunctionType>(PFTy->getElementType());
if (!FTy || !FTy->getReturnType()->isVoidTy() ||
FTy->isVarArg() || FTy->getNumParams() != 0)
return 0;
// Verify that the initializer is simple enough for us to handle. We are
// only allowed to optimize the initializer if it is unique.
if (!GV->hasUniqueInitializer()) return 0;
ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
if (!CA) return 0;
ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
ConstantStruct *CS = dyn_cast<ConstantStruct>(*i);
if (CS == 0) return 0;
ConstantStruct *CS = cast<ConstantStruct>(*i);
if (isa<ConstantPointerNull>(CS->getOperand(1)))
continue;
@ -1982,8 +1967,8 @@ GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
return 0;
// Init priority must be standard.
ConstantInt *CI = dyn_cast<ConstantInt>(CS->getOperand(0));
if (!CI || CI->getZExtValue() != 65535)
ConstantInt *CI = cast<ConstantInt>(CS->getOperand(0));
if (CI->getZExtValue() != 65535)
return 0;
}

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@ -471,6 +471,23 @@ void Verifier::visitGlobalVariable(GlobalVariable &GV) {
"invalid linkage type for global declaration", &GV);
}
if (GV.hasName() && (GV.getName() == "llvm.global_ctors" ||
GV.getName() == "llvm.global_dtors")) {
Assert1(!GV.hasInitializer() || GV.hasAppendingLinkage(),
"invalid linkage for intrinsic global variable", &GV);
// Don't worry about emitting an error for it not being an array,
// visitGlobalValue will complain on appending non-array.
if (const ArrayType *ATy = dyn_cast<ArrayType>(GV.getType())) {
const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
const PointerType *FuncPtrTy =
FunctionType::get(Type::getVoidTy(*Context), false)->getPointerTo();
Assert1(STy && STy->getNumElements() == 2 &&
STy->getTypeAtIndex(0u)->isIntegerTy(32) &&
STy->getTypeAtIndex(1) == FuncPtrTy,
"wrong type for intrinsic global variable", &GV);
}
}
visitGlobalValue(GV);
}