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First cut at setting attributes for functions and calls; this puts us

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much closer to passing the gcc struct layout tests.

It might be possible to refactor this a bit, but I'm not sure there's 
actually enough common code for that to be useful.

To get the calling convention completely correct, a bit of 
platform-specific code is necessary even for x86-Linux. On x86-Linux, the
alignment of function parameters is extremely strange; as far as I can tell,
it's always 4 except for SSE vectors or structs containing SSE vectors.  I'm 
continuing to investigate this.

llvm-svn: 51839
This commit is contained in:
Eli Friedman
2008-06-01 15:54:49 +00:00
parent 10c2417570
commit f6b091f73a
4 changed files with 90 additions and 34 deletions
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65
clang/lib/CodeGen/CodeGenModule.cpp
View File

@@ -183,6 +183,66 @@ void CodeGenModule::ReplaceMapValuesWith(llvm::Constant *OldVal,
if (I->second == OldVal) I->second = NewVal;
}
bool hasAggregateLLVMType(QualType T) {
return !T->isRealType() && !T->isPointerLikeType() &&
!T->isVoidType() && !T->isVectorType() && !T->isFunctionType();
}
void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD,
llvm::Function *F,
const llvm::FunctionType *FTy) {
unsigned FuncAttrs = 0;
if (FD->getAttr<NoThrowAttr>())
FuncAttrs |= llvm::ParamAttr::NoUnwind;
if (FD->getAttr<NoReturnAttr>())
FuncAttrs |= llvm::ParamAttr::NoReturn;
llvm::SmallVector<llvm::ParamAttrsWithIndex, 8> ParamAttrList;
if (FuncAttrs)
ParamAttrList.push_back(llvm::ParamAttrsWithIndex::get(0, FuncAttrs));
// Note that there is parallel code in CodeGenFunction::EmitCallExpr
bool AggregateReturn = hasAggregateLLVMType(FD->getResultType());
if (AggregateReturn)
ParamAttrList.push_back(
llvm::ParamAttrsWithIndex::get(1, llvm::ParamAttr::StructRet));
unsigned increment = AggregateReturn ? 2 : 1;
for (unsigned i = 0; i < FD->getNumParams(); i++) {
QualType ParamType = FD->getParamDecl(i)->getType();
unsigned ParamAttrs = 0;
if (ParamType->isRecordType())
ParamAttrs |= llvm::ParamAttr::ByVal;
if (ParamType->isSignedIntegerType() && ParamType->isPromotableIntegerType())
ParamAttrs |= llvm::ParamAttr::SExt;
if (ParamType->isUnsignedIntegerType() && ParamType->isPromotableIntegerType())
ParamAttrs |= llvm::ParamAttr::ZExt;
if (ParamAttrs)
ParamAttrList.push_back(llvm::ParamAttrsWithIndex::get(i + increment,
ParamAttrs));
}
F->setParamAttrs(llvm::PAListPtr::get(ParamAttrList.begin(),
ParamAttrList.size()));
// Set the appropriate calling convention for the Function.
if (FD->getAttr<FastCallAttr>())
F->setCallingConv(llvm::CallingConv::Fast);
// TODO: Set up linkage and many other things. Note, this is a simple
// approximation of what we really want.
if (FD->getStorageClass() == FunctionDecl::Static)
F->setLinkage(llvm::Function::InternalLinkage);
else if (FD->getAttr<DLLImportAttr>())
F->setLinkage(llvm::Function::DLLImportLinkage);
else if (FD->getAttr<DLLExportAttr>())
F->setLinkage(llvm::Function::DLLExportLinkage);
else if (FD->getAttr<WeakAttr>() || FD->isInline())
F->setLinkage(llvm::Function::WeakLinkage);
if (const VisibilityAttr *attr = FD->getAttr<VisibilityAttr>())
CodeGenModule::setVisibility(F, attr->getVisibility());
// FIXME: else handle -fvisibility
}
llvm::Constant *CodeGenModule::GetAddrOfFunctionDecl(const FunctionDecl *D,
bool isDefinition) {
@@ -202,9 +262,7 @@ llvm::Constant *CodeGenModule::GetAddrOfFunctionDecl(const FunctionDecl *D,
F = llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
D->getName(), &getModule());
// Set the appropriate calling convention for the Function.
if (D->getAttr<FastCallAttr>())
F->setCallingConv(llvm::CallingConv::Fast);
SetFunctionAttributes(D, F, FTy);
return Entry = F;
}
@@ -243,6 +301,7 @@ llvm::Constant *CodeGenModule::GetAddrOfFunctionDecl(const FunctionDecl *D,
assert(F->isDeclaration() && "Shouldn't replace non-declaration");
F->eraseFromParent();
SetFunctionAttributes(D, NewFn, FTy);
// Return the new function which has the right type.
return Entry = NewFn;
}