PATCH: Fix PR objc/19321 and assorted bogosities

[Ziemowit Laski <zlaski at apple dot com>]

This patch (finally!) fixes the mysterious loss of volatile-ness 
experienced by PARM_DECLs
in ObjC methods.  I'm not terribly proud of the objc.dg/volatile-1.m 
test case, as it only really works for PowerPC Darwin targets; I'm 
hoping people can add assembly patterns to search for on their own 
platforms.  Or perhaps there is a better, target-independent way of 
testing this; suggestions are welcome and encouraged.

While I was at it, I also fixed problems with using functions as ObjC 
method parameters; the proper decay to pointers was not happening, and 
this is a regression from gcc 3.x.

I'll wait until tomorrow for comments before committing.

--Zem

[gcc/objc/ChangeLog]
2005-01-15  Ziemowit Laski  <zlaski@apple.com>

        PR objc/19321
        * objc-act.c (get_arg_type_list): Decay function arguments into
        pointers.
        (objc_push_parm): Likewise; bring PARM_DECL construction closer
        in line with what the C front-end does.
        (objc_get_parm_info): Call pushdecl() and finish_decl() on
        each PARM_DECL, like the C front-end does.
        (start_method_def): Remove redundant ARRAY_TYPE decay.
        (objc_start_function): Bring closer in line with what the
        C front-end does for functions.

[gcc/testsuite/ChangeLog]
2005-01-15  Ziemowit Laski  <zlaski@apple.com>

        PR objc/19321
        * objc.dg/func-ptr-2.m: New.
        * objc.dg/volatile-1.m: New.


Index: gcc/objc/objc-act.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/objc/objc-act.c,v
retrieving revision 1.260
diff -u -3 -p -r1.260 objc-act.c
--- gcc/objc/objc-act.c 2 Jan 2005 07:52:28 -0000       1.260
+++ gcc/objc/objc-act.c 15 Jan 2005 02:12:47 -0000
@@ -5298,9 +5298,11 @@ get_arg_type_list (tree meth, int contex
     {
       tree arg_type = TREE_VALUE (TREE_TYPE (akey));

-      /* Decay arrays into pointers.  */
+      /* Decay arrays and functions into pointers.  */
       if (TREE_CODE (arg_type) == ARRAY_TYPE)
        arg_type = build_pointer_type (TREE_TYPE (arg_type));
+      else if (TREE_CODE (arg_type) == FUNCTION_TYPE)
+       arg_type = build_pointer_type (arg_type);

       chainon (arglist, build_tree_list (NULL_TREE, arg_type));
     }
@@ -7379,11 +7381,21 @@ static GTY(()) tree objc_parmlist = NULL
 static void
 objc_push_parm (tree parm)
 {
-  /* Convert array parameters of unknown size into pointers.  */
-  if (TREE_CODE (TREE_TYPE (parm)) == ARRAY_TYPE
-      && !TYPE_SIZE (TREE_TYPE (parm)))
+  /* Decay arrays and functions into pointers.  */
+  if (TREE_CODE (TREE_TYPE (parm)) == ARRAY_TYPE)
     TREE_TYPE (parm) = build_pointer_type (TREE_TYPE (TREE_TYPE 
(parm)));
+  else if (TREE_CODE (TREE_TYPE (parm)) == FUNCTION_TYPE)
+    TREE_TYPE (parm) = build_pointer_type (TREE_TYPE (parm));

+  DECL_ARG_TYPE_AS_WRITTEN (parm) = TREE_TYPE (parm);
+  DECL_ARG_TYPE (parm) = c_type_promotes_to (TREE_TYPE (parm));
+
+  /* Record constancy and volatility.  */
+  c_apply_type_quals_to_decl
+  ((TYPE_READONLY (TREE_TYPE (parm)) ? TYPE_QUAL_CONST : 0)
+   | (TYPE_RESTRICT (TREE_TYPE (parm)) ? TYPE_QUAL_RESTRICT : 0)
+   | (TYPE_VOLATILE (TREE_TYPE (parm)) ? TYPE_QUAL_VOLATILE : 0), 
parm);
+
   objc_parmlist = chainon (objc_parmlist, parm);
 }

@@ -7415,7 +7427,8 @@ objc_get_parm_info (int have_ellipsis)
       tree next = TREE_CHAIN (parm_info);

       TREE_CHAIN (parm_info) = NULL_TREE;
-      pushdecl (parm_info);
+      parm_info = pushdecl (parm_info);
+      finish_decl (parm_info, NULL_TREE, NULL_TREE);
       parm_info = next;
     }
   arg_info = get_parm_info (have_ellipsis);
@@ -7477,10 +7490,6 @@ start_method_def (tree method)
     {
       tree type = TREE_VALUE (TREE_TYPE (parmlist)), parm;

-      /* Decay arrays into pointers.  */
-      if (TREE_CODE (type) == ARRAY_TYPE)
-       type = build_pointer_type (TREE_TYPE (type));
-
       parm = build_decl (PARM_DECL, KEYWORD_ARG_NAME (parmlist), type);
       objc_push_parm (parm);
       parmlist = TREE_CHAIN (parmlist);
@@ -7619,24 +7628,26 @@ objc_start_function (tree name, tree typ

 #ifdef OBJCPLUS
   DECL_ARGUMENTS (fndecl) = params;
-#endif
   DECL_INITIAL (fndecl) = error_mark_node;
   DECL_EXTERNAL (fndecl) = 0;
   TREE_STATIC (fndecl) = 1;
-
-#ifdef OBJCPLUS
   retrofit_lang_decl (fndecl);
   cplus_decl_attributes (&fndecl, attrs, 0);
   start_preparsed_function (fndecl, attrs, /*flags=*/SF_DEFAULT);
 #else
   decl_attributes (&fndecl, attrs, 0);
   announce_function (fndecl);
+  DECL_INITIAL (fndecl) = error_mark_node;
+  DECL_EXTERNAL (fndecl) = 0;
+  TREE_STATIC (fndecl) = 1;
   current_function_decl = pushdecl (fndecl);
   push_scope ();
   declare_parm_level ();
   DECL_RESULT (current_function_decl)
     = build_decl (RESULT_DECL, NULL_TREE,
                  TREE_TYPE (TREE_TYPE (current_function_decl)));
+  DECL_ARTIFICIAL (DECL_RESULT (current_function_decl)) = 1;
+  DECL_IGNORED_P (DECL_RESULT (current_function_decl)) = 1;
   start_fname_decls ();
   store_parm_decls_from (params);
 #endif
Index: gcc/testsuite/objc.dg/func-ptr-2.m
===================================================================
RCS file: gcc/testsuite/objc.dg/func-ptr-2.m
diff -N gcc/testsuite/objc.dg/func-ptr-2.m
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ gcc/testsuite/objc.dg/func-ptr-2.m  15 Jan 2005 02:12:57 -0000
@@ -0,0 +1,37 @@
+/* Check if method parameters that are functions are gracefully decayed
+   into pointers.  */
+/* Contributed by Ziemowit Laski  <zlaski@apple.com>  */
+/* { dg-do run } */
+
+#include <objc/Object.h>
+#include <stdlib.h>
+
+@interface Func: Object
++ (int) processNumber:(int)a and:(int)b 
usingFunction:(int(int,int))func;
+@end
+
+@implementation Func
++ (int) processNumber:(int)a and:(int)b 
usingFunction:(int(int,int))func {
+  return func (a, b);
+}
+@end
+
+static int my_computation(int a, int b) {
+  return a * 2 + b * 3;
+}
+
+static int processNumber(int a, int b, int func(int, int)) {
+  return func(a, b);
+}
+
+int main(void) {
+  int result = processNumber (6, 8, my_computation);
+  if (result != 36)
+    abort ();
+
+  result = [Func processNumber:8 and:6 usingFunction:my_computation];
+  if (result != 34)
+    abort ();
+
+  return 0;
+}
Index: gcc/testsuite/objc.dg/volatile-1.m
===================================================================
RCS file: gcc/testsuite/objc.dg/volatile-1.m
diff -N gcc/testsuite/objc.dg/volatile-1.m
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ gcc/testsuite/objc.dg/volatile-1.m  15 Jan 2005 02:12:57 -0000
@@ -0,0 +1,18 @@
+/* Test for proper handling of volatile parameters in ObjC methods.  */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* Contributed by Ziemowit Laski  <zlaski@apple.com>  */
+
+@interface Test
+-(void) test2: (volatile int) a;
+@end
+
+@implementation Test
+-(void) test2: (volatile int) a
+{
+  /* The following assignment should NOT be optimized away.  */
+  a = 1;
+}
+@end
+
+/* { dg-final { scan-assembler "li r\[0-9\]+,1" { target 
powerpc*-*-darwin* } } } */