Don't look through casts when looking for the underlying decl for a function

call; the standard doesn't expect us to, and the program could be doing
something crazy.  Fixes PR5882.

llvm-svn: 92166

clang/lib/Sema/SemaExpr.cpp

@@ -3373,7 +3373,7 @@ Sema::ActOnCallExpr(Scope *S, ExprArg fn, SourceLocation LParenLoc,
   // Also, in C++, keep track of whether we should perform argument-dependent
   // lookup and whether there were any explicitly-specified template arguments.
 
-  Expr *NakedFn = Fn->IgnoreParenCasts();
+  Expr *NakedFn = Fn->IgnoreParens();
   if (isa<UnresolvedLookupExpr>(NakedFn)) {
     UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(NakedFn);
     return BuildOverloadedCallExpr(Fn, ULE, LParenLoc, Args, NumArgs,

clang/test/CodeGen/func-ptr-cast-decl.c

@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -emit-llvm-only %s -verify
+// PR5882
+
+int q_sk_num(void *a);
+typedef int (*fptr)(double);
+void a() { ((fptr)q_sk_num)(0); }