re PR c/67730 (No warning when returning NULL in void function)

	PR c/67730
	* c-typeck.c (convert_for_assignment): Use the expansion point
	location throughout.

	* gcc.dg/pr67730-1.c: New test.
	* gcc.dg/pr67730-2.c: New test.
	* gcc.dg/pr67730.h: New test.

From-SVN: r228408

gcc/c/ChangeLog

 2015-10-02  Marek Polacek  <polacek@redhat.com>
 
+	PR c/67730
+	* c-typeck.c (convert_for_assignment): Use the expansion point
+	location throughout.
+
+2015-10-02  Marek Polacek  <polacek@redhat.com>
+
 	PR c/64249
 	* c-parser.c (c_parser_statement_after_labels): Add CHAIN parameter
 	and pass it down to c_parser_if_statement.

gcc/c/c-typeck.c

@@ -5718,6 +5718,10 @@ convert_for_assignment (location_t location, location_t expr_loc, tree type,
   tree rname = NULL_TREE;
   bool objc_ok = false;
 
+  /* Use the expansion point location to handle cases such as user's
+     function returning a wrong-type macro defined in a system header.  */
+  location = expansion_point_location_if_in_system_header (location);
+
   if (errtype == ic_argpass)
     {
       tree selector;

gcc/testsuite/ChangeLog

 2015-10-02  Marek Polacek  <polacek@redhat.com>
 
+	PR c/67730
+	* gcc.dg/pr67730-1.c: New test.
+	* gcc.dg/pr67730-2.c: New test.
+	* gcc.dg/pr67730.h: New test.
+
+2015-10-02  Marek Polacek  <polacek@redhat.com>
+
 	* c-c++-common/Wduplicated-cond-2.c: Skip until PR67819 is resolved.
 
 2015-10-02  Sebastian Pop  <s.pop@samsung.com>

gcc/testsuite/gcc.dg/pr67730-1.c

+/* PR c/67730 */
+/* { dg-do compile } */
+/* { dg-options "-Wc++-compat" } */
+
+#include "pr67730.h"
+
+extern void bar (unsigned char *);
+
+unsigned char *
+f (void *p)
+{
+   unsigned char *uc = ONEP; /* { dg-warning "request for implicit conversion" } */
+   uc = ONEP; /* { dg-warning "request for implicit conversion" } */
+   bar (ONEP); /* { dg-warning "request for implicit conversion" } */
+   return ONEP; /* { dg-warning "request for implicit conversion" } */
+}

gcc/testsuite/gcc.dg/pr67730-2.c

+/* PR c/67730 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+#include "pr67730.h"
+
+extern void bar (int);
+
+int
+fn1 (void)
+{
+  int a = NULL; /* { dg-warning "initialization makes integer from pointer" } */
+  a = NULL; /* { dg-warning "assignment makes integer from pointer" } */
+  bar (NULL); /* { dg-warning "passing argument 1" } */
+  return NULL; /* { dg-warning "return makes integer from pointer" } */
+}
+
+int
+fn2 (void)
+{
+  RETURN; /* { dg-warning "return makes integer from pointer" } */
+}

gcc/testsuite/gcc.dg/pr67730.h

+#pragma GCC system_header
+#define NULL (void *) 0
+#define ONEP (void *) 1
+#define RETURN return NULL
+
+extern void sysbar (unsigned char *);
+
+unsigned char *
+sysfn1 (void *p)
+{
+   unsigned char *uc = ONEP;
+   uc = ONEP;
+   sysbar (ONEP);
+   return ONEP;
+}
+
+extern void sysbar2 (int);
+
+int
+sysfn2 (void)
+{
+  int a = NULL;
+  a = NULL;
+  sysbar2 (NULL);
+  return NULL;
+}
+
+int
+sysfn3 (void)
+{
+  RETURN;
+}