gcc/config/darwin-c.c

   1 /* Darwin support needed only by C/C++ frontends.
   2    Copyright (C) 2001, 2003  Free Software Foundation, Inc.
   3    Contributed by Apple Computer Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "cpplib.h"
  27 #include "tree.h"
  28 #include "c-pragma.h"
  29 #include "c-tree.h"
  30 #include "toplev.h"
  31 #include "tm_p.h"
  32
  33 /* Pragmas.  */
  34
  35 #define BAD(msgid) do { warning (msgid); return; } while (0)
  36
  37 /* Maintain a small stack of alignments.  This is similar to pragma
  38    pack's stack, but simpler.  */
  39
  40 static void push_field_alignment (int);
  41 static void pop_field_alignment (void);
  42
  43 typedef struct align_stack
  44 {
  45   int alignment;
  46   struct align_stack * prev;
  47 } align_stack;
  48
  49 static struct align_stack * field_align_stack = NULL;
  50
  51 static void
  52 push_field_alignment (int bit_alignment)
  53 {
  54   align_stack *entry = (align_stack *) xmalloc (sizeof (align_stack));
  55
  56   entry->alignment = maximum_field_alignment;
  57   entry->prev = field_align_stack;
  58   field_align_stack = entry;
  59
  60   maximum_field_alignment = bit_alignment;
  61 }
  62
  63 static void
  64 pop_field_alignment (void)
  65 {
  66   if (field_align_stack)
  67     {
  68       align_stack *entry = field_align_stack;
  69
  70       maximum_field_alignment = entry->alignment;
  71       field_align_stack = entry->prev;
  72       free (entry);
  73     }
  74   else
  75     error ("too many #pragma options align=reset");
  76 }
  77
  78 /* Handlers for Darwin-specific pragmas.  */
  79
  80 void
  81 darwin_pragma_ignore (cpp_reader *pfile ATTRIBUTE_UNUSED)
  82 {
  83   /* Do nothing.  */
  84 }
  85
  86 /* #pragma options align={mac68k|power|reset} */
  87
  88 void
  89 darwin_pragma_options (cpp_reader *pfile ATTRIBUTE_UNUSED)
  90 {
  91   const char *arg;
  92   tree t, x;
  93
  94   if (c_lex (&t) != CPP_NAME)
  95     BAD ("malformed '#pragma options', ignoring");
  96   arg = IDENTIFIER_POINTER (t);
  97   if (strcmp (arg, "align"))
  98     BAD ("malformed '#pragma options', ignoring");
  99   if (c_lex (&t) != CPP_EQ)
 100     BAD ("malformed '#pragma options', ignoring");
 101   if (c_lex (&t) != CPP_NAME)
 102     BAD ("malformed '#pragma options', ignoring");
 103
 104   if (c_lex (&x) != CPP_EOF)
 105     warning ("junk at end of '#pragma options'");
 106
 107   arg = IDENTIFIER_POINTER (t);
 108   if (!strcmp (arg, "mac68k"))
 109     push_field_alignment (16);
 110   else if (!strcmp (arg, "power"))
 111     push_field_alignment (0);
 112   else if (!strcmp (arg, "reset"))
 113     pop_field_alignment ();
 114   else
 115     warning ("malformed '#pragma options align={mac68k|power|reset}', ignoring");
 116 }
 117
 118 /* #pragma unused ([var {, var}*]) */
 119
 120 void
 121 darwin_pragma_unused (cpp_reader *pfile ATTRIBUTE_UNUSED)
 122 {
 123   tree decl, x;
 124   int tok;
 125
 126   if (c_lex (&x) != CPP_OPEN_PAREN)
 127     BAD ("missing '(' after '#pragma unused', ignoring");
 128
 129   while (1)
 130     {
 131       tok = c_lex (&decl);
 132       if (tok == CPP_NAME && decl)
 133         {
 134           tree local = lookup_name (decl);
 135           if (local && (TREE_CODE (local) == PARM_DECL
 136                         || TREE_CODE (local) == VAR_DECL))
 137             TREE_USED (local) = 1;
 138           tok = c_lex (&x);
 139           if (tok != CPP_COMMA)
 140             break;
 141         }
 142     }
 143
 144   if (tok != CPP_CLOSE_PAREN)
 145     BAD ("missing ')' after '#pragma unused', ignoring");
 146
 147   if (c_lex (&x) != CPP_EOF)
 148     warning ("junk at end of '#pragma unused'");
 149 }