re PR middle-end/68582 (-Wunused-function doesn't warn about unused static…

re PR middle-end/68582 (-Wunused-function doesn't warn about unused static __attribute__((noreturn)) functions)

	PR middle-end/68582
	* cgraphunit.c (check_global_declaration): Only depend on TREE_THIS_VOLATILE
	for VAR_DECLs.

	* c-c++-common/pr68582.c: New test.

From-SVN: r231116

gcc/ChangeLog

+2015-12-01  Marek Polacek  <polacek@redhat.com>
+
+	PR middle-end/68582
+	* cgraphunit.c (check_global_declaration): Only depend on TREE_THIS_VOLATILE
+	for VAR_DECLs.
+
 2015-12-01  Richard Sandiford  <richard.sandiford@arm.com>
 
 	PR tree-optimization/68474

gcc/cgraphunit.c

@@ -956,7 +956,7 @@ check_global_declaration (symtab_node *snode)
       && ! DECL_ABSTRACT_ORIGIN (decl)
       && ! TREE_PUBLIC (decl)
       /* A volatile variable might be used in some non-obvious way.  */
-      && ! TREE_THIS_VOLATILE (decl)
+      && (! VAR_P (decl) || ! TREE_THIS_VOLATILE (decl))
       /* Global register variables must be declared to reserve them.  */
       && ! (TREE_CODE (decl) == VAR_DECL && DECL_REGISTER (decl))
       /* Global ctors and dtors are called by the runtime.  */

gcc/testsuite/ChangeLog

+2015-12-01  Marek Polacek  <polacek@redhat.com>
+
+	PR middle-end/68582
+	* c-c++-common/pr68582.c: New test.
+
 2015-12-01  Richard Sandiford  <richard.sandiford@arm.com>
 
 	PR tree-optimization/68474

gcc/testsuite/c-c++-common/pr68582.c

+/* PR middle-end/68582 */
+/* { dg-do compile } */
+/* { dg-options "-Wunused-function" } */
+
+/* We failed to give the warning for functions with TREE_THIS_VOLATILE set.  */
+
+static void
+fn1 (void) /* { dg-warning "defined but not used" } */
+{
+  __builtin_abort ();
+}
+
+__attribute__ ((noreturn))
+static void
+fn2 (void) /* { dg-warning "defined but not used" } */
+{
+  __builtin_abort ();
+}
+
+__attribute__ ((volatile))
+static void
+fn3 (void) /* { dg-warning "defined but not used" } */
+{
+  __builtin_abort ();
+}