nvptx.c (nvptx_assemble_undefined_decl): Reject undefined weak.

	* config/nvptx/nvptx.c (nvptx_assemble_undefined_decl): Reject
	undefined weak.

	testsuite/
	* c-c++-common/torture/pr57945.c: Add expected PTX error.
	* gcc.target/nvptx/weak.c: New.

From-SVN: r236990

gcc/ChangeLog

+2016-06-01  Nathan Sidwell  <nathan@acm.org>
+
+	* config/nvptx/nvptx.c (nvptx_assemble_undefined_decl): Reject
+	undefined weak.
+
 2016-06-01  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/71261
@@ -109,7 +114,8 @@
 2016-05-31  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	* config/sh/constraints.md (b): Remove constraint.
-	* config/sh/predicates.md (arith_reg_operand): Remove TARGET_REGISTER_P.
+	* config/sh/predicates.md (arith_reg_operand): Remove
+	TARGET_REGISTER_P.
 	* config/sh/sh-modes.def (PDI): Remove.
 	* config/sh/sh.c (sh_target_reg_class,
 	sh_optimize_target_register_callee_saved): Remove functions.

gcc/config/nvptx/nvptx.c

@@ -1777,6 +1777,12 @@ nvptx_assemble_undefined_decl (FILE *file, const char *name, const_tree decl)
   if (DECL_IN_CONSTANT_POOL (decl))
     return;
 
+  /*  We support weak defintions, and hence have the right
+      ASM_WEAKEN_DECL definition.  Diagnose the problem here.  */
+  if (DECL_WEAK (decl))
+    error_at (DECL_SOURCE_LOCATION (decl),
+	      "PTX does not support weak declarations"
+	      " (only weak definitions)");
   write_var_marker (file, false, TREE_PUBLIC (decl), name);
 
   fprintf (file, "\t.extern ");

gcc/testsuite/ChangeLog

+2016-06-01  Nathan Sidwell  <nathan@acm.org>
+
+	* c-c++-common/torture/pr57945.c: Add expected PTX error.
+	* gcc.target/nvptx/weak.c: New.
+
 2016-06-01  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/71261

gcc/testsuite/c-c++-common/torture/pr57945.c

@@ -9,3 +9,5 @@ foo (void)
 {
   return &i ? i : 0;
 }
+
+/* { dg-error "PTX does not support weak declarations" "" { target nvptx-*-* } 5 } */

gcc/testsuite/gcc.target/nvptx/weak.c

+
+extern int __attribute__((weak)) decl;  /* { dg-error "weak declarations" } */
+int __attribute__((weak)) defn;
+
+int Foo ()
+{
+  return decl + defn;
+}
+