gcc/scan-decls.c

   1 /* scan-decls.c - Extracts declarations from cpp output.
   2    Copyright (C) 1993, 1995, 1997, 1998,
   3    1999, 2000, 2003, 2004 Free Software Foundation, Inc.
   4
   5 This program is free software; you can redistribute it and/or modify it
   6 under the terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option) any
   8 later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18
  19    Written by Per Bothner <bothner@cygnus.com>, July 1993.  */
  20
  21 #include "bconfig.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "cpplib.h"
  26 #include "scan.h"
  27
  28 static void skip_to_closing_brace (cpp_reader *);
  29 static const cpp_token *get_a_token (cpp_reader *);
  30
  31 int brace_nesting = 0;
  32
  33 /* The first extern_C_braces_length elements of extern_C_braces
  34    indicate the (brace nesting levels of) left braces that were
  35    prefixed by extern "C".  */
  36 int extern_C_braces_length = 0;
  37 /* 20 is not enough anymore on Solaris 9.  */
  38 #define MAX_EXTERN_C_BRACES  200
  39 char extern_C_braces[MAX_EXTERN_C_BRACES];
  40 #define in_extern_C_brace (extern_C_braces_length>0)
  41
  42 /* True if the function declaration currently being scanned is
  43    prefixed by extern "C".  */
  44 int current_extern_C = 0;
  45
  46 /* Get a token but skip padding.  */
  47 static const cpp_token *
  48 get_a_token (cpp_reader *pfile)
  49 {
  50   for (;;)
  51     {
  52       const cpp_token *result = cpp_get_token (pfile);
  53       if (result->type != CPP_PADDING)
  54         return result;
  55     }
  56 }
  57
  58 static void
  59 skip_to_closing_brace (cpp_reader *pfile)
  60 {
  61   int nesting = 1;
  62   for (;;)
  63     {
  64       enum cpp_ttype token = get_a_token (pfile)->type;
  65
  66       if (token == CPP_EOF)
  67         break;
  68       if (token == CPP_OPEN_BRACE)
  69         nesting++;
  70       if (token == CPP_CLOSE_BRACE && --nesting == 0)
  71         break;
  72     }
  73 }
  74
  75 /* This function scans a C source file (actually, the output of cpp),
  76    reading from FP.  It looks for function declarations, and
  77    external variable declarations.
  78
  79    The following grammar (as well as some extra stuff) is recognized:
  80
  81    declaration:
  82      (decl-specifier)* declarator ("," declarator)* ";"
  83    decl-specifier:
  84      identifier
  85      keyword
  86      extern "C"
  87    declarator:
  88      (ptr-operator)* dname [ "(" argument-declaration-list ")" ]
  89    ptr-operator:
  90      ("*" | "&") ("const" | "volatile")*
  91    dname:
  92      identifier
  93
  94 Here dname is the actual name being declared.
  95 */
  96
  97 int
  98 scan_decls (cpp_reader *pfile, int argc ATTRIBUTE_UNUSED,
  99             char **argv ATTRIBUTE_UNUSED)
 100 {
 101   int saw_extern, saw_inline;
 102   cpp_token prev_id;
 103   const cpp_token *token;
 104
 105  new_statement:
 106   token = get_a_token (pfile);
 107
 108  handle_statement:
 109   current_extern_C = 0;
 110   saw_extern = 0;
 111   saw_inline = 0;
 112   if (token->type == CPP_OPEN_BRACE)
 113     {
 114       /* Pop an 'extern "C"' nesting level, if appropriate.  */
 115       if (extern_C_braces_length
 116           && extern_C_braces[extern_C_braces_length - 1] == brace_nesting)
 117         extern_C_braces_length--;
 118       brace_nesting--;
 119       goto new_statement;
 120     }
 121   if (token->type == CPP_OPEN_BRACE)
 122     {
 123       brace_nesting++;
 124       goto new_statement;
 125     }
 126
 127   if (token->type == CPP_EOF)
 128     return 0;
 129
 130   if (token->type == CPP_SEMICOLON)
 131     goto new_statement;
 132   if (token->type != CPP_NAME)
 133     goto new_statement;
 134
 135   prev_id.type = CPP_EOF;
 136   for (;;)
 137     {
 138       switch (token->type)
 139         {
 140         default:
 141           goto handle_statement;
 142         case CPP_MULT:
 143         case CPP_AND:
 144           /* skip */
 145           break;
 146
 147         case CPP_COMMA:
 148         case CPP_SEMICOLON:
 149           if (prev_id.type != CPP_EOF && saw_extern)
 150             {
 151               recognized_extern (&prev_id);
 152             }
 153           if (token->type == CPP_COMMA)
 154             break;
 155           /* ... fall through ...  */
 156         case CPP_OPEN_BRACE:  case CPP_CLOSE_BRACE:
 157           goto new_statement;
 158
 159         case CPP_EOF:
 160           return 0;
 161
 162         case CPP_OPEN_PAREN:
 163           /* Looks like this is the start of a formal parameter list.  */
 164           if (prev_id.type != CPP_EOF)
 165             {
 166               int nesting = 1;
 167               int have_arg_list = 0;
 168               const struct line_map *map;
 169               unsigned int line;
 170               for (;;)
 171                 {
 172                   token = get_a_token (pfile);
 173                   if (token->type == CPP_OPEN_PAREN)
 174                     nesting++;
 175                   else if (token->type == CPP_CLOSE_PAREN)
 176                     {
 177                       nesting--;
 178                       if (nesting == 0)
 179                         break;
 180                     }
 181                   else if (token->type == CPP_EOF)
 182                     break;
 183                   else if (token->type == CPP_NAME
 184                            || token->type == CPP_ELLIPSIS)
 185                     have_arg_list = 1;
 186                 }
 187               map = linemap_lookup (&line_table, token->src_loc);
 188               line = SOURCE_LINE (map, token->src_loc);
 189               recognized_function (&prev_id, line,
 190                                    (saw_inline ? 'I'
 191                                     : in_extern_C_brace || current_extern_C
 192                                     ? 'F' : 'f'), have_arg_list);
 193               token = get_a_token (pfile);
 194               if (token->type == CPP_OPEN_BRACE)
 195                 {
 196                   /* skip body of (normally) inline function */
 197                   skip_to_closing_brace (pfile);
 198                   goto new_statement;
 199                 }
 200
 201               /* skip a possible __attribute__ or throw expression after the
 202                  parameter list */
 203               while (token->type != CPP_SEMICOLON && token->type != CPP_EOF)
 204                 token = get_a_token (pfile);
 205               goto new_statement;
 206             }
 207           break;
 208         case CPP_NAME:
 209           /* "inline" and "extern" are recognized but skipped */
 210           if (cpp_ideq (token, "inline"))
 211             {
 212               saw_inline = 1;
 213             }
 214           else if (cpp_ideq (token, "extern"))
 215             {
 216               saw_extern = 1;
 217               token = get_a_token (pfile);
 218               if (token->type == CPP_STRING
 219                   && token->val.str.len == 1
 220                   && token->val.str.text[0] == 'C')
 221                 {
 222                   current_extern_C = 1;
 223                   token = get_a_token (pfile);
 224                   if (token->type == CPP_OPEN_BRACE)
 225                     {
 226                       brace_nesting++;
 227                       extern_C_braces[extern_C_braces_length++]
 228                         = brace_nesting;
 229                       if (extern_C_braces_length >= MAX_EXTERN_C_BRACES)
 230                         {
 231                           fprintf (stderr,
 232                                    "Internal error: out-of-bounds index\n");
 233                           exit (FATAL_EXIT_CODE);
 234                         }
 235                       goto new_statement;
 236                     }
 237                 }
 238               else
 239                 continue;
 240               break;
 241             }
 242           /* This may be the name of a variable or function.  */
 243           prev_id = *token;
 244           break;
 245         }
 246       token = get_a_token (pfile);
 247     }
 248 }