C99 DR #316 implies that the function parameter types that are known
only from a function definition (that does not have a prototype) are
only used to determine the compatible with other declarations of that
same function. In particular, when referencing the function we pretend
as if it does not have a prototype. Implement this behavior, which
fixes PR3626.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 174e408..98d6b12 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -873,6 +873,19 @@
CheckS = CheckS->getParent();
}
}
+ } else if (FunctionDecl *Func = dyn_cast<FunctionDecl>(VD)) {
+ if (!getLangOptions().CPlusPlus && !Func->hasPrototype()) {
+ // C99 DR 316 says that, if a function type comes from a
+ // function definition (without a prototype), that type is only
+ // used for checking compatibility. Therefore, when referencing
+ // the function, we pretend that we don't have the full function
+ // type.
+ QualType T = Func->getType();
+ QualType NoProtoType = T;
+ if (const FunctionTypeProto *Proto = T->getAsFunctionTypeProto())
+ NoProtoType = Context.getFunctionTypeNoProto(Proto->getResultType());
+ return Owned(BuildDeclRefExpr(VD, NoProtoType, Loc, false, false, SS));
+ }
}
// Only create DeclRefExpr's for valid Decl's.