implement codegen for functions whose function body type don't match
their prototype.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@44506 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CodeGen/CodeGenFunction.cpp b/CodeGen/CodeGenFunction.cpp
index 0da5fcd..190da77 100644
--- a/CodeGen/CodeGenFunction.cpp
+++ b/CodeGen/CodeGenFunction.cpp
@@ -58,8 +58,42 @@
getContext().getTypeSize(getContext().getPointerType(getContext().VoidTy),
SourceLocation()));
- CurFn = cast<llvm::Function>(CGM.GetAddrOfGlobalDecl(FD));
CurFuncDecl = FD;
+ llvm::Constant *CurFnC = CGM.GetAddrOfGlobalDecl(FD);
+ if (!(CurFn = dyn_cast<llvm::Function>(CurFnC))) {
+ // If CurFnC is not a constant, it must be a bitcast of another function.
+ llvm::ConstantExpr *CurFnCE = cast<llvm::ConstantExpr>(CurFnC);
+ assert(CurFnCE->getOpcode() == llvm::Instruction::BitCast &&
+ "Unexpected name collision");
+ llvm::Function *OtherFunc = cast<llvm::Function>(CurFnCE->getOperand(0));
+
+ // This happens if there is a prototype for a function (e.g. "int f()") and
+ // then a definition of a different type (e.g. "int f(int x)"). Start by
+ // making a new function of the correct type, RAUW, then steal the name.
+ const llvm::PointerType *PTy = cast<llvm::PointerType>(CurFnC->getType());
+ const llvm::FunctionType *FTy =
+ cast<llvm::FunctionType>(PTy->getElementType());
+ CurFn = new llvm::Function(FTy, llvm::Function::ExternalLinkage, "",
+ &CGM.getModule());
+ CurFn->takeName(OtherFunc);
+
+ // Replace uses of OtherFunc with the Function we will endow with a body.
+ llvm::Constant *NewPtrForOldDecl =
+ llvm::ConstantExpr::getBitCast(CurFn, OtherFunc->getType());
+ OtherFunc->replaceAllUsesWith(NewPtrForOldDecl);
+
+ // Make sure the GlobalDecl map for FD is up-to-date.
+ CGM.ChangeGlobalDeclMap(FD, CurFn);
+
+ // FIXME: Update the globaldeclmap for the previous decl of this name. We
+ // really want a way to walk all of these, but we don't have it yet. This
+ // is incredibly slow!
+ CGM.ReplaceMapValuesWith(OtherFunc, NewPtrForOldDecl);
+
+ // Ok, delete the old function now, which is dead.
+ assert(OtherFunc->isDeclaration() && "Shouldn't replace non-declaration");
+ OtherFunc->eraseFromParent();
+ }
assert(CurFn->isDeclaration() && "Function already has body?");
diff --git a/CodeGen/CodeGenModule.cpp b/CodeGen/CodeGenModule.cpp
index b76d5e3..51f758c 100644
--- a/CodeGen/CodeGenModule.cpp
+++ b/CodeGen/CodeGenModule.cpp
@@ -31,6 +31,18 @@
: Context(C), Features(LO), TheModule(M), TheTargetData(TD), Diags(diags),
Types(C, M, TD), MemCpyFn(0), CFConstantStringClassRef(0) {}
+
+/// ReplaceMapValuesWith - This is a really slow and bad function that
+/// searches for any entries in GlobalDeclMap that point to OldVal, changing
+/// them to point to NewVal. This is badbadbad, FIXME!
+void CodeGenModule::ReplaceMapValuesWith(llvm::Constant *OldVal,
+ llvm::Constant *NewVal) {
+ for (llvm::DenseMap<const Decl*, llvm::Constant*>::iterator
+ I = GlobalDeclMap.begin(), E = GlobalDeclMap.end(); I != E; ++I)
+ if (I->second == OldVal) I->second = NewVal;
+}
+
+
llvm::Constant *CodeGenModule::GetAddrOfGlobalDecl(const ValueDecl *D) {
// See if it is already in the map.
llvm::Constant *&Entry = GlobalDeclMap[D];
diff --git a/CodeGen/CodeGenModule.h b/CodeGen/CodeGenModule.h
index c4867c0..dd4c006 100644
--- a/CodeGen/CodeGenModule.h
+++ b/CodeGen/CodeGenModule.h
@@ -68,6 +68,15 @@
llvm::Constant *GetAddrOfGlobalDecl(const ValueDecl *D);
+ void ChangeGlobalDeclMap(const Decl *Decl, llvm::Constant *NewVal) {
+ GlobalDeclMap[Decl] = NewVal;
+ }
+
+ /// ReplaceMapValuesWith - This is a really slow and bad function that
+ /// searches for any entries in GlobalDeclMap that point to OldVal, changing
+ /// them to point to NewVal. This is badbadbad, FIXME!
+ void ReplaceMapValuesWith(llvm::Constant *OldVal, llvm::Constant *NewVal);
+
/// getBuiltinLibFunction - Given a builtin id for a function like
/// "__builtin_fabsf", return a Function* for "fabsf".
///