PATCH: Make ObjC an extension of C

[Ziemowit Laski <zlaski at apple dot com>]

Hi all,

The main purpose of this patch is to remove clk_objective_c as
a distinct language supported by the C-flavored front-ends.  Instead,
Objective-C acquires the status of an _extension_ to the C language;
the 'compiling_objc' flag is introduced to keep track of whether this
extension is being used.  Currently, compiling_objc is unconditionally
set by cc1obj, and left cleared by cc1.  As we move towards a unified
front-end, however, compiling_objc will have to be controlled by its
own flag ('-fobjc'?).  This control will be independent of the specific
variant of C (e.g., C94, C99, etc.) desired.

Such an arrangement results in a much cleaner separation of the
ObjC machinery from the base language.  In the case of the FSF,
the base language can currently be any of the C variants.  In Apple's
case, the base language can also be C++, which is how Objective-C++
is implemented.  Hopefully, future work on the unified, recursive-
descent parser will allow Objective-C++ to appear in the FSF as well.

This patch is just the initial one in a series of fixes to ObjC that
we have done in gcc 3.1 in preparation for the Mac OS X 10.2
(aka Jaguar) release.  It is only now that we actually have the time
to prepare the FSF submissions. :(

This has bootstrapped cleanly on i686-pc-linux-gnu, with no regressions
in any of the dejagnu test suites.  We'd like to put it in TOT so that
it winds up on the 3.3 release branch later.

OK?


2002-08-08  Ziemowit Laski  <zlaski@apple.com>

        * c-common.c (c_common_init_options): Remove uses of
        clk_objective_c, replace with compiling_objc as needed.
        * c-common.h (c_language_kind): Get rid of clk_objective_c
        enum value.
        (compiling_objc): New extern declaration.
        * c-decl.c (implicitly_declare): Call objc_check_decl
        instead of maybe_objc_check_decl.
        (finish_decl): Likewise.
        (grokfield): Likewise.
        (finish_struct): Likewise.
        * c-lang.c (maybe_objc_check_decl): Rename to objc_check_decl.
        (maybe_objc_comptypes): Rename to objc_comptypes.
        (maybe_building_objc_message_expr): Rename to
        objc_message_selector.
        * c-lex.c (c_common_init_options): Remove uses of
        clk_objective_c, replace with compiling_objc as needed.
        (c_common_decode_option): Likewise.
        * c-parse.in (init_reswords): Likewise.
        * c-tree.h (maybe_objc_check_decl): Rename to objc_check_decl.
        (maybe_objc_comptypes): Rename to objc_comptypes.
        (maybe_building_objc_message_expr): Rename to
        objc_message_selector.
        * c-typeck.c (comptypes): Call objc_comptypes instead of
        maybe_objc_comptypes, and/or objc_message_selector instead of
        maybe_building_objc_message_expr.
        (comp_target_types): Likewise.
        (convert_for_assignment): Likewise.
        (warn_for_assignment): Likewise.
        cppinit.c (set_lang): Adjust for how Objective-C mode is
        represented.
        (init_standard_includes): Likewise.
        (cpp_handle_option): Move case OPT_lang_objc so that it
        falls through to OPT_lang_c.
        * cpplib.h (compiling_objc): Add extern declaration.
        * cppmain.c (compiling_objc): Add definition.
        * fix_header.c (compiling_objc): Likewise.
        * objc/objc-act.c (maybe_objc_comptypes): Delete.
        (maybe_objc_check_decl): Delete.
        (maybe_building_objc_message_expr): Rename to
        objc_message_selector.
        * objc/objc-lang.c (objc_init_options): Use clk_c instead of
        clk_objective_c; set compiling_objc flag.


Index: gcc/c-common.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-common.c,v
retrieving revision 1.359
diff -c -3 -p -r1.359 c-common.c
*** gcc/c-common.c      2 Aug 2002 04:18:16 -0000       1.359
--- gcc/c-common.c      7 Aug 2002 21:01:09 -0000
*************** c_common_init_options (lang)
*** 4652,4660 ****
       enum c_language_kind lang;
  {
    c_language = lang;
!   parse_in = cpp_create_reader (lang == clk_c || lang == 
clk_objective_c
!                               ? CLK_GNUC89 : CLK_GNUCXX);
!   if (lang == clk_objective_c)
      cpp_get_options (parse_in)->objc = 1;

    flag_const_strings = (lang == clk_cplusplus);
--- 4652,4659 ----
       enum c_language_kind lang;
  {
    c_language = lang;
!   parse_in = cpp_create_reader (lang == clk_c ? CLK_GNUC89 : 
CLK_GNUCXX);
!   if (compiling_objc)
      cpp_get_options (parse_in)->objc = 1;

    flag_const_strings = (lang == clk_cplusplus);
Index: gcc/c-common.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-common.h,v
retrieving revision 1.147
diff -c -3 -p -r1.147 c-common.h
*** gcc/c-common.h      1 Aug 2002 06:20:30 -0000       1.147
--- gcc/c-common.h      7 Aug 2002 21:01:10 -0000
*************** typedef enum c_language_kind
*** 240,247 ****
  {
    clk_c,           /* A dialect of C: K&R C, ANSI/ISO C89, C2000,
                       etc.  */
!   clk_cplusplus,   /* ANSI/ISO C++ */
!   clk_objective_c  /* Objective C */
  }
  c_language_kind;

--- 240,246 ----
  {
    clk_c,           /* A dialect of C: K&R C, ANSI/ISO C89, C2000,
                       etc.  */
!   clk_cplusplus   /* ANSI/ISO C++ */
  }
  c_language_kind;

*************** struct c_lang_decl GTY(()) {
*** 367,372 ****
--- 366,375 ----

  extern c_language_kind c_language;

+ /* The following flag is non-zero whenever ObjC or ObjC++ is being
+    compiled.  */
+
+ extern int compiling_objc;

  /* Switches common to the C front ends.  */

*************** extern int warn_deprecated;
*** 793,801 ****
     infinite template instantiations.  */

  extern int max_tinst_depth;
-
-
-

  /* C types are partitioned into three subsets: object, function, and
     incomplete types.  */
--- 796,801 ----
Index: gcc/c-decl.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-decl.c,v
retrieving revision 1.344
diff -c -3 -p -r1.344 c-decl.c
*** gcc/c-decl.c        1 Aug 2002 06:20:30 -0000       1.344
--- gcc/c-decl.c        7 Aug 2002 21:01:13 -0000
*************** implicitly_declare (functionid)
*** 2307,2314 ****
       So we record the decl in the standard fashion.  */
    pushdecl (decl);

!   /* This is a no-op in c-lang.c or something real in objc-actions.c. 
 */
!   maybe_objc_check_decl (decl);

    rest_of_decl_compilation (decl, NULL, 0, 0);

--- 2307,2315 ----
       So we record the decl in the standard fashion.  */
    pushdecl (decl);

!   /* This is a no-op in c-lang.c or something real in objc-act.c.  */
!   if (compiling_objc)
!     objc_check_decl (decl);

    rest_of_decl_compilation (decl, NULL, 0, 0);

*************** finish_decl (decl, init, asmspec_tree)
*** 3345,3352 ****

    if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == 
FUNCTION_DECL)
      {
!       /* This is a no-op in c-lang.c or something real in 
objc-actions.c.  */
!       maybe_objc_check_decl (decl);

        if (!DECL_CONTEXT (decl))
        {
--- 3346,3354 ----

    if (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == 
FUNCTION_DECL)
      {
!       /* This is a no-op in c-lang.c or something real in objc-act.c. 
 */
!       if (compiling_objc)
!       objc_check_decl (decl);

        if (!DECL_CONTEXT (decl))
        {
*************** finish_decl (decl, init, asmspec_tree)
*** 3408,3415 ****

    if (TREE_CODE (decl) == TYPE_DECL)
      {
!       /* This is a no-op in c-lang.c or something real in 
objc-actions.c.  */
!       maybe_objc_check_decl (decl);
        rest_of_decl_compilation (decl, NULL, DECL_CONTEXT (decl) == 0, 
0);
      }

--- 3410,3418 ----

    if (TREE_CODE (decl) == TYPE_DECL)
      {
!       /* This is a no-op in c-lang.c or something real in objc-act.c. 
 */
!       if (compiling_objc)
!       objc_check_decl (decl);
        rest_of_decl_compilation (decl, NULL, DECL_CONTEXT (decl) == 0, 
0);
      }

*************** grokfield (filename, line, declarator, d
*** 5257,5263 ****
    finish_decl (value, NULL_TREE, NULL_TREE);
    DECL_INITIAL (value) = width;

!   maybe_objc_check_decl (value);
    return value;
  }


--- 5260,5267 ----
    finish_decl (value, NULL_TREE, NULL_TREE);
    DECL_INITIAL (value) = width;

!   if (compiling_objc)
!     objc_check_decl (value);
    return value;
  }


*************** finish_struct (t, fieldlist, attributes)
*** 5545,5552 ****
              && TREE_CODE (decl) != TYPE_DECL)
            {
              layout_decl (decl, 0);
!             /* This is a no-op in c-lang.c or something real in 
objc-actions.c.  */
!             maybe_objc_check_decl (decl);
              rest_of_decl_compilation (decl, NULL, toplevel, 0);
              if (! toplevel)
                expand_decl (decl);
--- 5549,5557 ----
              && TREE_CODE (decl) != TYPE_DECL)
            {
              layout_decl (decl, 0);
!             /* This is a no-op in c-lang.c or something real in 
objc-act.c.  */
!             if (compiling_objc)
!               objc_check_decl (decl);
              rest_of_decl_compilation (decl, NULL, toplevel, 0);
              if (! toplevel)
                expand_decl (decl);
*************** finish_struct (t, fieldlist, attributes)
*** 5568,5574 ****
                  if (TREE_CODE (decl) != TYPE_DECL)
                    {
                      layout_decl (decl, 0);
!                     maybe_objc_check_decl (decl);
                      rest_of_decl_compilation (decl, NULL, toplevel, 
0);
                      if (! toplevel)
                        expand_decl (decl);
--- 5573,5580 ----
                  if (TREE_CODE (decl) != TYPE_DECL)
                    {
                      layout_decl (decl, 0);
!                     if (compiling_objc)
!                       objc_check_decl (decl);
                      rest_of_decl_compilation (decl, NULL, toplevel, 
0);
                      if (! toplevel)
                        expand_decl (decl);
Index: gcc/c-lang.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-lang.c,v
retrieving revision 1.95
diff -c -3 -p -r1.95 c-lang.c
*** gcc/c-lang.c        26 Jul 2002 13:45:33 -0000      1.95
--- gcc/c-lang.c        7 Aug 2002 21:01:14 -0000
*************** is_class_name (arg)
*** 183,195 ****
  }

  void
! maybe_objc_check_decl (decl)
       tree decl ATTRIBUTE_UNUSED;
  {
  }

  int
! maybe_objc_comptypes (lhs, rhs, reflexive)
       tree lhs ATTRIBUTE_UNUSED;
       tree rhs ATTRIBUTE_UNUSED;
       int reflexive ATTRIBUTE_UNUSED;
--- 183,195 ----
  }

  void
! objc_check_decl (decl)
       tree decl ATTRIBUTE_UNUSED;
  {
  }

  int
! objc_comptypes (lhs, rhs, reflexive)
       tree lhs ATTRIBUTE_UNUSED;
       tree rhs ATTRIBUTE_UNUSED;
       int reflexive ATTRIBUTE_UNUSED;
*************** maybe_objc_comptypes (lhs, rhs, reflexiv
*** 198,204 ****
  }

  tree
! maybe_building_objc_message_expr ()
  {
    return 0;
  }
--- 198,204 ----
  }

  tree
! building_objc_message_expr ()
  {
    return 0;
  }
Index: gcc/c-lex.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-lex.c,v
retrieving revision 1.185
diff -c -3 -p -r1.185 c-lex.c
*** gcc/c-lex.c 21 Jul 2002 21:59:02 -0000      1.185
--- gcc/c-lex.c 7 Aug 2002 21:01:16 -0000
*************** lex_charconst (token)
*** 1078,1084 ****
      type = wchar_type_node;
    /* In C, a character constant has type 'int'.
       In C++ 'char', but multi-char charconsts have type 'int'.  */
!   else if ((c_language == clk_c || c_language == clk_objective_c)
           || chars_seen > 1)
      type = integer_type_node;
    else
--- 1078,1084 ----
      type = wchar_type_node;
    /* In C, a character constant has type 'int'.
       In C++ 'char', but multi-char charconsts have type 'int'.  */
!   else if (c_language == clk_c
           || chars_seen > 1)
      type = integer_type_node;
    else
Index: gcc/c-parse.in
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-parse.in,v
retrieving revision 1.150
diff -c -3 -p -r1.150 c-parse.in
*** gcc/c-parse.in      26 Jul 2002 16:23:05 -0000      1.150
--- gcc/c-parse.in      7 Aug 2002 21:01:17 -0000
*************** init_reswords ()
*** 3546,3552 ****
    int mask = (flag_isoc99 ? 0 : D_C89)
              | (flag_no_asm ? (flag_isoc99 ? D_EXT : D_EXT|D_EXT89) : 
0);

!   if (c_language != clk_objective_c)
       mask |= D_OBJC;

    /* It is not necessary to register ridpointers as a GC root, because
--- 3546,3552 ----
    int mask = (flag_isoc99 ? 0 : D_C89)
              | (flag_no_asm ? (flag_isoc99 ? D_EXT : D_EXT|D_EXT89) : 
0);

!   if (!compiling_objc)
       mask |= D_OBJC;

    /* It is not necessary to register ridpointers as a GC root, because
Index: gcc/c-tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-tree.h,v
retrieving revision 1.102
diff -c -3 -p -r1.102 c-tree.h
*** gcc/c-tree.h        1 Aug 2002 06:20:31 -0000       1.102
--- gcc/c-tree.h        7 Aug 2002 21:01:18 -0000
*************** struct lang_type GTY(())
*** 165,174 ****
  /* in c-lang.c and objc-act.c */
  extern tree lookup_interface                  PARAMS ((tree));
  extern tree is_class_name                     PARAMS ((tree));
! extern void maybe_objc_check_decl             PARAMS ((tree));
  extern void finish_file                               PARAMS ((void));
! extern int maybe_objc_comptypes                 PARAMS ((tree, tree, 
int));
! extern tree maybe_building_objc_message_expr    PARAMS ((void));
  extern int recognize_objc_keyword             PARAMS ((void));
  extern tree lookup_objc_ivar                  PARAMS ((tree));

--- 165,174 ----
  /* in c-lang.c and objc-act.c */
  extern tree lookup_interface                  PARAMS ((tree));
  extern tree is_class_name                     PARAMS ((tree));
! extern void objc_check_decl                   PARAMS ((tree));
  extern void finish_file                               PARAMS ((void));
! extern int objc_comptypes                     PARAMS ((tree, tree, 
int));
! extern tree building_objc_message_expr        PARAMS ((void));
  extern int recognize_objc_keyword             PARAMS ((void));
  extern tree lookup_objc_ivar                  PARAMS ((tree));

Index: gcc/cppinit.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cppinit.c,v
retrieving revision 1.248
diff -c -3 -p -r1.248 cppinit.c
*** gcc/cppinit.c       2 Aug 2002 04:18:16 -0000       1.248
--- gcc/cppinit.c       7 Aug 2002 21:01:20 -0000
*************** set_lang (pfile, lang)
*** 412,417 ****
--- 412,418 ----
    const struct lang_flags *l = &lang_defaults[(int) lang];

    CPP_OPTION (pfile, lang) = lang;
+   CPP_OPTION (pfile, objc) = compiling_objc;

    CPP_OPTION (pfile, c99)              = l->c99;
    CPP_OPTION (pfile, cplusplus)                = l->cplusplus;
*************** init_standard_includes (pfile)
*** 727,733 ****
    if (path != 0 && *path != 0)
      path_include (pfile, path, BRACKET);

!   switch ((CPP_OPTION (pfile, objc) << 1) + CPP_OPTION (pfile, 
cplusplus))
      {
      case 0:
        GET_ENVIRONMENT (path, "C_INCLUDE_PATH");
--- 728,734 ----
    if (path != 0 && *path != 0)
      path_include (pfile, path, BRACKET);

!   switch ((CPP_OPTION (pfile, objc) ? 2 : 0) + CPP_OPTION (pfile, 
cplusplus))
      {
      case 0:
        GET_ENVIRONMENT (path, "C_INCLUDE_PATH");
*************** cpp_handle_option (pfile, argc, argv)
*** 1440,1453 ****
          CPP_OPTION (pfile, include_prefix) = arg;
          CPP_OPTION (pfile, include_prefix_len) = strlen (arg);
          break;
        case OPT_lang_c:
          set_lang (pfile, CLK_GNUC89);
          break;
        case OPT_lang_cplusplus:
          set_lang (pfile, CLK_GNUCXX);
-         break;
-       case OPT_lang_objc:
-         CPP_OPTION (pfile, objc) = 1;
          break;
        case OPT_lang_asm:
          set_lang (pfile, CLK_ASM);
--- 1441,1454 ----
          CPP_OPTION (pfile, include_prefix) = arg;
          CPP_OPTION (pfile, include_prefix_len) = strlen (arg);
          break;
+       case OPT_lang_objc:
+         compiling_objc = 1;
+         /* Fall through.  */
        case OPT_lang_c:
          set_lang (pfile, CLK_GNUC89);
          break;
        case OPT_lang_cplusplus:
          set_lang (pfile, CLK_GNUCXX);
          break;
        case OPT_lang_asm:
          set_lang (pfile, CLK_ASM);
Index: gcc/cpplib.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cpplib.h,v
retrieving revision 1.227
diff -c -3 -p -r1.227 cpplib.h
*** gcc/cpplib.h        23 Jul 2002 22:57:44 -0000      1.227
--- gcc/cpplib.h        7 Aug 2002 21:01:22 -0000
*************** enum cpp_ttype
*** 154,159 ****
--- 154,160 ----
  /* C language kind, used when calling cpp_reader_init.  */
  enum c_lang {CLK_GNUC89 = 0, CLK_GNUC99, CLK_STDC89, CLK_STDC94, 
CLK_STDC99,
             CLK_GNUCXX, CLK_CXX98, CLK_ASM};
+ extern int compiling_objc;

  /* Payload of a NUMBER, STRING, CHAR or COMMENT token.  */
  struct cpp_string
Index: gcc/cppmain.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cppmain.c,v
retrieving revision 1.101
diff -c -3 -p -r1.101 cppmain.c
*** gcc/cppmain.c       29 Jun 2002 15:49:23 -0000      1.101
--- gcc/cppmain.c       7 Aug 2002 21:01:23 -0000
*************** static void cb_ident      PARAMS ((cpp_read
*** 62,67 ****
--- 62,71 ----
  static void cb_file_change PARAMS ((cpp_reader *, const struct 
line_map *));
  static void cb_def_pragma PARAMS ((cpp_reader *, unsigned int));

+ /* ObjC and ObjC++ no longer have their own rows; instead, 
compiling_objc is
+    set on top of another C/C++ dialect.  */
+ int compiling_objc = 0;
+
  static cpp_options *options;  /* Options of pfile.  */
  static struct printer print;

Index: gcc/fix-header.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fix-header.c,v
retrieving revision 1.83
diff -c -3 -p -r1.83 fix-header.c
*** gcc/fix-header.c    23 Jul 2002 06:21:52 -0000      1.83
--- gcc/fix-header.c    7 Aug 2002 21:01:24 -0000
*************** fatal VPARAMS ((const char *str, ...))
*** 1324,1326 ****
--- 1324,1330 ----
    v_fatal (str, ap);
    VA_CLOSE (ap);
  }
+
+ /* ObjC and ObjC++ no longer have their own rows; instead, 
compiling_objc is
+    set on top of another C/C++ dialect.  */
+ int compiling_objc = 0;
Index: gcc/objc/objc-act.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/objc/objc-act.c,v
retrieving revision 1.147
diff -c -3 -p -r1.147 objc-act.c
*** gcc/objc/objc-act.c 1 Aug 2002 15:43:51 -0000       1.147
--- gcc/objc/objc-act.c 7 Aug 2002 21:01:26 -0000
*************** define_decl (declarator, declspecs)
*** 559,572 ****
     `a' and `b' are the same class type, or
     `a' and `b' are of class types A and B such that B is a descendant 
of A.  */

- int
- maybe_objc_comptypes (lhs, rhs, reflexive)
-      tree lhs, rhs;
-      int reflexive;
- {
-   return objc_comptypes (lhs, rhs, reflexive);
- }
-
  static tree
  lookup_method_in_protocol_list (rproto_list, sel_name, class_meth)
     tree rproto_list;
--- 559,564 ----
*************** objc_check_decl (decl)
*** 805,817 ****
      error_with_decl (decl, "`%s' cannot be statically allocated");
  }

- void
- maybe_objc_check_decl (decl)
-      tree decl;
- {
-   objc_check_decl (decl);
- }
-
  /* Implement static typing.  At this point, we know we have an 
interface.  */

  tree
--- 797,802 ----
*************** receiver_is_class_object (receiver)
*** 4705,4711 ****
  static tree building_objc_message_expr = 0;

  tree
! maybe_building_objc_message_expr ()
  {
    return building_objc_message_expr;
  }
--- 4690,4696 ----
  static tree building_objc_message_expr = 0;

  tree
! building_objc_message_expr ()
  {
    return building_objc_message_expr;
  }
Index: gcc/objc/objc-lang.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/objc/objc-lang.c,v
retrieving revision 1.24
diff -c -3 -p -r1.24 objc-lang.c
*** gcc/objc/objc-lang.c        6 Jun 2002 09:25:48 -0000       1.24
--- gcc/objc/objc-lang.c        7 Aug 2002 21:01:27 -0000
*************** static void objc_init_options
*** 115,120 ****
--- 115,131 ----
  /* Each front end provides its own hooks, for toplev.c.  */
  const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;

+ static void
+ objc_init_options ()
+ {
+   compiling_objc = 1;
+ #ifdef OBJCPLUS
+   cxx_init_options (clk_cplusplus);
+ #else
+   c_common_init_options (clk_c);
+ #endif
+ }
+
  /* Define the special tree codes that we use.  */

  /* Table indexed by tree code giving a string containing a character

--------------------------------------------------------------
Ziemowit Laski                 1 Infinite Loop, MS 301-2K
Mac OS X Compiler Group        Cupertino, CA USA  95014-2083
Apple Computer, Inc.           +1.408.974.6229  Fax .5477