Error about alias attribute with body definition (PR c/87483).

2018-10-04  Martin Liska  <mliska@suse.cz>

	PR c/87483
	* cgraphunit.c (process_function_and_variable_attributes):
	Warn about a function with alias attribute and a body.
2018-10-04  Martin Liska  <mliska@suse.cz>

	PR c/87483
	* gcc.dg/pr87483.c: New test.

From-SVN: r264846

gcc/ChangeLog

 2018-10-04  Martin Liska  <mliska@suse.cz>
 
+	PR c/87483
+	* cgraphunit.c (process_function_and_variable_attributes):
+	Warn about a function with alias attribute and a body.
+
+2018-10-04  Martin Liska  <mliska@suse.cz>
+
 	PR ipa/82625
 	* multiple_target.c (redirect_to_specific_clone): New function.
 	(ipa_target_clone): Use it.

gcc/cgraphunit.c

@@ -784,6 +784,12 @@ process_function_and_variable_attributes (cgraph_node *first,
 	  DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
 						     DECL_ATTRIBUTES (decl));
 	}
+      else if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl))
+	  && node->definition
+	  && !node->alias)
+	warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wattributes,
+		    "%<alias%> attribute ignored"
+		    " because function is defined");
 
       if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (decl))
 	  && !DECL_DECLARED_INLINE_P (decl)

gcc/testsuite/ChangeLog

 2018-10-04  Martin Liska  <mliska@suse.cz>
 
+	PR c/87483
+	* gcc.dg/pr87483.c: New test.
+
+2018-10-04  Martin Liska  <mliska@suse.cz>
+
 	PR ipa/82625
 	* g++.dg/ext/pr82625.C: New test.
 

gcc/testsuite/gcc.dg/pr87483.c

+/* PR c/87483 */
+/* { dg-require-alias "" } */
+
+int f (void) { return 0; }
+__attribute__ ((alias ("f"))) int g () { return 1; } /* { dg-warning "attribute ignored because function is defined" } */
+__attribute__ ((alias ("f"))) int g2 ();
+
+int h (void)
+{
+  return g2 ();
+}
+
+int main()
+{
+  return h();
+}