[C PATCH] Fix up location used in get_parm_info diagnostics (PR c/68533)

[Jakub Jelinek <jakub@redhat.com>]

Hi!

get_parm_info right now uses input_location as the diagnostics locus, but as
can be seen on the testcase, that is pretty random location at that point,
often the type of the last parameter.

This patch changes it to use the locus from the binding info.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2015-12-01  Jakub Jelinek  <jakub@redhat.com>

	PR c/68533
	* c-decl.c (get_parm_info): Use b->locus instead of input_location
	for diagnostics.

	* gcc.dg/pr68533.c: New test.

--- gcc/c/c-decl.c.jj	2015-11-30 13:40:35.000000000 +0100
+++ gcc/c/c-decl.c	2015-12-01 16:14:40.466462666 +0100
@@ -6913,11 +6913,11 @@ get_parm_info (bool ellipsis, tree expr)
     {
       if (TYPE_QUALS (TREE_TYPE (b->decl)) != TYPE_UNQUALIFIED
 	  || C_DECL_REGISTER (b->decl))
-	error ("%<void%> as only parameter may not be qualified");
+	error_at (b->locus, "%<void%> as only parameter may not be qualified");
 
       /* There cannot be an ellipsis.  */
       if (ellipsis)
-	error ("%<void%> must be the only parameter");
+	error_at (b->locus, "%<void%> must be the only parameter");
 
       arg_info->types = void_list_node;
       return arg_info;
@@ -6946,13 +6946,14 @@ get_parm_info (bool ellipsis, tree expr)
 
 	  /* Check for forward decls that never got their actual decl.  */
 	  if (TREE_ASM_WRITTEN (decl))
-	    error ("parameter %q+D has just a forward declaration", decl);
+	    error_at (b->locus,
+		      "parameter %q+D has just a forward declaration", decl);
 	  /* Check for (..., void, ...) and issue an error.  */
 	  else if (VOID_TYPE_P (type) && !DECL_NAME (decl))
 	    {
 	      if (!gave_void_only_once_err)
 		{
-		  error ("%<void%> must be the only parameter");
+		  error_at (b->locus, "%<void%> must be the only parameter");
 		  gave_void_only_once_err = true;
 		}
 	    }
@@ -6991,13 +6992,13 @@ get_parm_info (bool ellipsis, tree expr)
 	    {
 	      if (b->id)
 		/* The %s will be one of 'struct', 'union', or 'enum'.  */
-		warning_at (input_location, 0,
+		warning_at (b->locus, 0,
 			    "%<%s %E%> declared inside parameter list"
 			    " will not be visible outside of this definition or"
 			    " declaration", keyword, b->id);
 	      else
 		/* The %s will be one of 'struct', 'union', or 'enum'.  */
-		warning_at (input_location, 0,
+		warning_at (b->locus, 0,
 			    "anonymous %s declared inside parameter list"
 			    " will not be visible outside of this definition or"
 			    " declaration", keyword);
--- gcc/testsuite/gcc.dg/pr68533.c.jj	2015-12-01 18:47:55.864178841 +0100
+++ gcc/testsuite/gcc.dg/pr68533.c	2015-12-01 18:48:56.000000000 +0100
@@ -0,0 +1,68 @@
+/* PR c/68533 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+struct T { int t; };
+
+void
+f1 (
+  struct S *	/* { dg-warning "declared inside parameter list will not be visible outside of this definition or declaration" } */
+  x,
+  struct T *
+  y
+   )
+{
+  y->t = 4;
+}
+
+void
+f2 (
+  struct {int s;} * /* { dg-warning "anonymous struct declared inside parameter list will not be visible outside of this definition or declaration" } */
+  x,
+  struct T *
+  y
+   )
+{
+  y->t = 5;
+}
+
+void
+f3 (
+  const void
+   )		/* { dg-error "'void' as only parameter may not be qualified" } */
+{
+}
+
+void
+f4 (
+   void,	/* { dg-error "'void' must be the only parameter" } */
+   ...
+   )
+{
+}
+
+void
+f5 (
+   int
+   x;		/* { dg-error "parameter 'x' has just a forward declaration" } */
+   int y
+   )
+{
+}
+
+void
+f6 (
+   int
+   x,
+   void
+   )		/* { dg-error "'void' must be the only parameter" } */
+{
+}
+
+void
+f7 (
+   void,	/* { dg-error "'void' must be the only parameter" } */
+   int y
+   )
+{
+}

	Jakub