gcc/config/darwin-c.c

   1 /* Darwin support needed only by C/C++ frontends.
   2    Copyright (C) 2001
   3    Free Software Foundation, Inc.
   4    Contributed by Apple Computer Inc.
   5
   6 This file is part of GNU CC.
   7
   8 GNU CC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GNU CC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU CC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "cpplib.h"
  28 #include "tree.h"
  29 #include "c-pragma.h"
  30 #include "c-tree.h"
  31 #include "toplev.h"
  32 #include "tm_p.h"
  33
  34 /* Pragmas.  */
  35
  36 #define BAD(msgid) do { warning (msgid); return; } while (0)
  37
  38 /* Maintain a small stack of alignments.  This is similar to pragma
  39    pack's stack, but simpler.  */
  40
  41 static void push_field_alignment PARAMS ((int));
  42 static void pop_field_alignment PARAMS ((void));
  43
  44 typedef struct align_stack
  45 {
  46   int alignment;
  47   struct align_stack * prev;
  48 } align_stack;
  49
  50 static struct align_stack * field_align_stack = NULL;
  51
  52 static void
  53 push_field_alignment (bit_alignment)
  54      int bit_alignment;
  55 {
  56   align_stack *entry = (align_stack *) xmalloc (sizeof (align_stack));
  57
  58   entry->alignment = maximum_field_alignment;
  59   entry->prev = field_align_stack;
  60   field_align_stack = entry;
  61
  62   maximum_field_alignment = bit_alignment;
  63 }
  64
  65 static void
  66 pop_field_alignment ()
  67 {
  68   if (field_align_stack)
  69     {
  70       align_stack *entry = field_align_stack;
  71
  72       maximum_field_alignment = entry->alignment;
  73       field_align_stack = entry->prev;
  74       free (entry);
  75     }
  76   else
  77     error ("too many #pragma options align=reset");
  78 }
  79
  80 /* Handlers for Darwin-specific pragmas.  */
  81
  82 void
  83 darwin_pragma_ignore (pfile)
  84      cpp_reader *pfile ATTRIBUTE_UNUSED;
  85 {
  86   /* Do nothing.  */
  87 }
  88
  89 /* #pragma options align={mac68k|power|reset} */
  90
  91 void
  92 darwin_pragma_options (pfile)
  93      cpp_reader *pfile ATTRIBUTE_UNUSED;
  94 {
  95   const char *arg;
  96   tree t, x;
  97
  98   if (c_lex (&t) != CPP_NAME)
  99     BAD ("malformed '#pragma options', ignoring");
 100   arg = IDENTIFIER_POINTER (t);
 101   if (strcmp (arg, "align"))
 102     BAD ("malformed '#pragma options', ignoring");
 103   if (c_lex (&t) != CPP_EQ)
 104     BAD ("malformed '#pragma options', ignoring");
 105   if (c_lex (&t) != CPP_NAME)
 106     BAD ("malformed '#pragma options', ignoring");
 107
 108   if (c_lex (&x) != CPP_EOF)
 109     warning ("junk at end of '#pragma options'");
 110
 111   arg = IDENTIFIER_POINTER (t);
 112   if (!strcmp (arg, "mac68k"))
 113     push_field_alignment (16);
 114   else if (!strcmp (arg, "power"))
 115     push_field_alignment (0);
 116   else if (!strcmp (arg, "reset"))
 117     pop_field_alignment ();
 118   else
 119     warning ("malformed '#pragma options align={mac68k|power|reset}', ignoring");
 120 }
 121
 122 /* #pragma unused ([var {, var}*]) */
 123
 124 void
 125 darwin_pragma_unused (pfile)
 126      cpp_reader *pfile ATTRIBUTE_UNUSED;
 127 {
 128   tree decl, x;
 129   int tok;
 130
 131   if (c_lex (&x) != CPP_OPEN_PAREN)
 132     BAD ("missing '(' after '#pragma unused', ignoring");
 133
 134   while (1)
 135     {
 136       tok = c_lex (&decl);
 137       if (tok == CPP_NAME && decl)
 138         {
 139           tree local = IDENTIFIER_LOCAL_VALUE (decl);
 140           if (local && (TREE_CODE (local) == PARM_DECL
 141                         || TREE_CODE (local) == VAR_DECL))
 142             TREE_USED (local) = 1;
 143           tok = c_lex (&x);
 144           if (tok != CPP_COMMA)
 145             break;
 146         }
 147     }
 148
 149   if (tok != CPP_CLOSE_PAREN)
 150     BAD ("missing ')' after '#pragma unused', ignoring");
 151
 152   if (c_lex (&x) != CPP_EOF)
 153     warning ("junk at end of '#pragma unused'");
 154 }