Change Sema::CheckAddressOfOperation() to respect C99-only addressof rules.
Remove diagnostics from Sema::CheckIndirectionOperand(). C89/C99 allow dereferencing an incomplete type. clang appears to be emulating some incorrect gcc behavior (see below).

void
foo (void)
{
 struct b;
 struct b* x = 0;
 struct b* y = &*x; // gcc produces an error ("dereferencing pointer to incomplete type")
}

With this patch, the above is now allowed.

Bug/Patch by Eli Friedman!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@45933 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/conditional-expr.c b/test/Sema/conditional-expr.c
index f6b9d1f..87fe2d2 100644
--- a/test/Sema/conditional-expr.c
+++ b/test/Sema/conditional-expr.c
@@ -1,7 +1,7 @@
 // RUN: clang -fsyntax-only -verify -pedantic %s
 void foo() {
   *(0 ? (double *)0 : (void *)0) = 0;
-  *((void *) 0) = 0; // -expected-warning {{dereferencing void pointer}} -expected-error {{incomplete type 'void' is not assignable}}
+  *((void *) 0) = 0; // -expected-error {{incomplete type 'void' is not assignable}}
   double *dp;
   int *ip;
   void *vp;