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 "cpplib.h"
  26 #include "tree.h"
  27 #include "c-pragma.h"
  28 #include "c-tree.h"
  29 #include "toplev.h"
  30 #include "tm_p.h"
  31
  32 /* Pragmas.  */
  33
  34 #define BAD(msgid) do { warning (msgid); return; } while (0)
  35
  36 /* Maintain a small stack of alignments.  This is similar to pragma
  37    pack's stack, but simpler.  */
  38
  39 static void push_field_alignment PARAMS ((int));
  40 static void pop_field_alignment PARAMS ((void));
  41
  42 typedef struct align_stack
  43 {
  44   int alignment;
  45   struct align_stack * prev;
  46 } align_stack;
  47
  48 static struct align_stack * field_align_stack = NULL;
  49
  50 static void
  51 push_field_alignment (bit_alignment)
  52      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 ()
  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 (pfile)
  82      cpp_reader *pfile ATTRIBUTE_UNUSED;
  83 {
  84   /* Do nothing.  */
  85 }
  86
  87 /* #pragma options align={mac68k|power|reset} */
  88
  89 void
  90 darwin_pragma_options (pfile)
  91      cpp_reader *pfile ATTRIBUTE_UNUSED;
  92 {
  93   const char *arg;
  94   tree t, x;
  95
  96   if (c_lex (&t) != CPP_NAME)
  97     BAD ("malformed '#pragma options', ignoring");
  98   arg = IDENTIFIER_POINTER (t);
  99   if (strcmp (arg, "align"))
 100     BAD ("malformed '#pragma options', ignoring");
 101   if (c_lex (&t) != CPP_EQ)
 102     BAD ("malformed '#pragma options', ignoring");
 103   if (c_lex (&t) != CPP_NAME)
 104     BAD ("malformed '#pragma options', ignoring");
 105
 106   if (c_lex (&x) != CPP_EOF)
 107     warning ("junk at end of '#pragma options'");
 108
 109   arg = IDENTIFIER_POINTER (t);
 110   if (!strcmp (arg, "mac68k"))
 111     push_field_alignment (16);
 112   else if (!strcmp (arg, "power"))
 113     push_field_alignment (0);
 114   else if (!strcmp (arg, "reset"))
 115     pop_field_alignment ();
 116   else
 117     warning ("malformed '#pragma options align={mac68k|power|reset}', ignoring");
 118 }
 119
 120 /* #pragma unused ([var {, var}*]) */
 121
 122 void
 123 darwin_pragma_unused (pfile)
 124      cpp_reader *pfile ATTRIBUTE_UNUSED;
 125 {
 126   tree decl, x;
 127   int tok;
 128
 129   if (c_lex (&x) != CPP_OPEN_PAREN)
 130     BAD ("missing '(' after '#pragma unused', ignoring");
 131
 132   while (1)
 133     {
 134       tok = c_lex (&decl);
 135       if (tok == CPP_NAME && decl)
 136         {
 137           tree local = IDENTIFIER_LOCAL_VALUE (decl);
 138           if (local && (TREE_CODE (local) == PARM_DECL
 139                         || TREE_CODE (local) == VAR_DECL))
 140             TREE_USED (local) = 1;
 141           tok = c_lex (&x);
 142           if (tok != CPP_COMMA)
 143             break;
 144         }
 145     }
 146
 147   if (tok != CPP_CLOSE_PAREN)
 148     BAD ("missing ')' after '#pragma unused', ignoring");
 149
 150   if (c_lex (&x) != CPP_EOF)
 151     warning ("junk at end of '#pragma unused'");
 152 }