re PR c/13519 (typeof(nonconst+const) is const)

	PR c/13519
	* c-typeck.c (composite_type, common_pointer_type): New functions.
	(common_type): Split parts into composite_type and
	common_pointer_type.  Ensure that arithmetic operations return
	unqualified types without attributes.  Don't make composite type
	of signed enum and compatible integer be unsigned.
	(build_conditional_expr, build_binary_op): Use
	common_pointer_type.
	* c-decl.c (merge_decls): Use composite_type.
	* c-tree.h (composite_type): Declare.

testsuite:
	* gcc.c-torture/enum-3.c, gcc.dg/pr13519-1.c: New tests.

From-SVN: r82671

gcc/ChangeLog

+2004-06-06  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/13519
+	* c-typeck.c (composite_type, common_pointer_type): New functions.
+	(common_type): Split parts into composite_type and
+	common_pointer_type.  Ensure that arithmetic operations return
+	unqualified types without attributes.  Don't make composite type
+	of signed enum and compatible integer be unsigned.
+	(build_conditional_expr, build_binary_op): Use
+	common_pointer_type.
+	* c-decl.c (merge_decls): Use composite_type.
+	* c-tree.h (composite_type): Declare.
+
 2004-06-06  Stephane Carrez  <stcarrez@nerim.fr>
 
 	PR target/14457

gcc/c-decl.c

@@ -1452,7 +1452,7 @@ merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
   /* Merge the data types specified in the two decls.  */
   TREE_TYPE (newdecl)
     = TREE_TYPE (olddecl)
-    = common_type (newtype, oldtype);
+    = composite_type (newtype, oldtype);
 
   /* Lay the type out, unless already done.  */
   if (oldtype != TREE_TYPE (newdecl))

gcc/c-tree.h

@@ -226,6 +226,7 @@ extern tree c_size_in_bytes (tree);
 extern bool c_mark_addressable (tree);
 extern void c_incomplete_type_error (tree, tree);
 extern tree c_type_promotes_to (tree);
+extern tree composite_type (tree, tree);
 extern tree build_component_ref (tree, tree);
 extern tree build_indirect_ref (tree, const char *);
 extern tree build_array_ref (tree, tree);

gcc/testsuite/ChangeLog

+2004-06-06  Joseph S. Myers  <jsm@polyomino.org.uk>
+
+	PR c/13519
+	* gcc.c-torture/enum-3.c, gcc.dg/pr13519-1.c: New tests.
+
 2004-06-06  Giovanni Bajo  <giovannibajo@gcc.gnu.org>
 
 	PR c++/15503

gcc/testsuite/gcc.c-torture/execute/enum-3.c

+/* The composite type of int and an enum compatible with int might be
+   either of the two types, but it isn't an unsigned type.  */
+/* Origin: Joseph Myers <jsm@polyomino.org.uk> */
+
+#include <limits.h>
+
+#include <stdio.h>
+
+extern void abort (void);
+extern void exit (int);
+
+enum e { a = INT_MIN };
+
+int *p;
+enum e *q;
+int
+main (void)
+{
+  enum e x = a;
+  q = &x;
+  if (*(1 ? q : p) > 0)
+    abort ();
+  exit (0);
+}

gcc/testsuite/gcc.dg/pr13519-1.c

+/* typeof applied to const+nonconst should be nonconst, as should
+   typeof applied to other arithmetic expressions.  Bug 13519.  */
+/* Origin: Debian bug report 208981
+   from Kalle Olavi Niemitalo <kon@iki.fi>, adapted to a testcase by
+   Joseph Myers <jsm@polyomino.org.uk>.  */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+void fn(void)
+{
+  int n;
+  const int c;
+
+  { __typeof__(n) a1; a1=0; }
+  { __typeof__(c) a2; a2=0; } /* { dg-error "read-only" "correct error" } */
+  { __typeof__((int)n) a3; a3=0; }
+  { __typeof__((int)c) a4; a4=0; } /* { dg-bogus "read-only" "bogus error" { xfail *-*-* } } */
+  { __typeof__((const int)n) a5; a5=0; } /* { dg-error "read-only" "correct error" { xfail *-*-* } } */
+  { __typeof__((const int)c) a6; a6=0; } /* { dg-error "read-only" "correct error" } */
+  { __typeof__(0) a7; a7=0; }
+  { __typeof__(1) a8; a8=0; }
+
+  { __typeof__(n+n) b0; b0=0; }
+  { __typeof__(n+c) b1; b1=0; }
+  { __typeof__(c+n) b2; b2=0; }
+  { __typeof__(c+c) b3; b3=0; }
+
+  { __typeof__(0+n) c0; c0=0; }
+  { __typeof__(0+c) c1; c1=0; }
+  { __typeof__(n+0) c2; c2=0; }
+  { __typeof__(c+0) c3; c3=0; }
+
+  { __typeof__(1+n) d0; d0=0; }
+  { __typeof__(1+c) d1; d1=0; }
+  { __typeof__(n+1) d2; d2=0; }
+  { __typeof__(c+1) d3; d3=0; }
+
+  { __typeof__(((int)n)+((int)n)) e0; e0=0; }
+  { __typeof__(((int)n)+((int)c)) e1; e1=0; }
+  { __typeof__(((int)c)+((int)n)) e2; e2=0; }
+  { __typeof__(((int)c)+((int)c)) e3; e3=0; }
+
+  { __typeof__(((const int)n)+((const int)n)) f0; f0=0; }
+  { __typeof__(((const int)n)+((const int)c)) f1; f1=0; }
+  { __typeof__(((const int)c)+((const int)n)) f2; f2=0; }
+  { __typeof__(((const int)c)+((const int)c)) f3; f3=0; }
+}