gcc/scan-decls.c

   1 /* scan-decls.c - Extracts declarations from cpp output.
   2    Copyright (C) 1993, 1995, 1997, 1998,
   3    1999, 2000 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19    Written by Per Bothner <bothner@cygnus.com>, July 1993.  */
  20
  21 #include "hconfig.h"
  22 #include "system.h"
  23 #include "cpplib.h"
  24 #include "scan.h"
  25
  26 static void skip_to_closing_brace PARAMS ((cpp_reader *));
  27 static const cpp_token *get_a_token PARAMS ((cpp_reader *));
  28
  29 int brace_nesting = 0;
  30
  31 /* The first extern_C_braces_length elements of extern_C_braces
  32    indicate the (brace nesting levels of) left braces that were
  33    prefixed by extern "C".  */
  34 int extern_C_braces_length = 0;
  35 char extern_C_braces[20];
  36 #define in_extern_C_brace (extern_C_braces_length>0)
  37
  38 /* True if the function declaration currently being scanned is
  39    prefixed by extern "C".  */
  40 int current_extern_C = 0;
  41
  42 /* Get a token but skip padding.  */
  43 static const cpp_token *
  44 get_a_token (pfile)
  45      cpp_reader *pfile;
  46 {
  47   for (;;)
  48     {
  49       const cpp_token *result = cpp_get_token (pfile);
  50       if (result->type != CPP_PADDING)
  51         return result;
  52     }
  53 }
  54
  55 static void
  56 skip_to_closing_brace (pfile)
  57      cpp_reader *pfile;
  58 {
  59   int nesting = 1;
  60   for (;;)
  61     {
  62       enum cpp_ttype token = get_a_token (pfile)->type;
  63
  64       if (token == CPP_EOF)
  65         break;
  66       if (token == CPP_OPEN_BRACE)
  67         nesting++;
  68       if (token == CPP_CLOSE_BRACE && --nesting == 0)
  69         break;
  70     }
  71 }
  72
  73 /* This function scans a C source file (actually, the output of cpp),
  74    reading from FP.  It looks for function declarations, and
  75    external variable declarations.
  76
  77    The following grammar (as well as some extra stuff) is recognized:
  78
  79    declaration:
  80      (decl-specifier)* declarator ("," declarator)* ";"
  81    decl-specifier:
  82      identifier
  83      keyword
  84      extern "C"
  85    declarator:
  86      (ptr-operator)* dname [ "(" argument-declaration-list ")" ]
  87    ptr-operator:
  88      ("*" | "&") ("const" | "volatile")*
  89    dname:
  90      identifier
  91
  92 Here dname is the actual name being declared.
  93 */
  94
  95 int
  96 scan_decls (pfile, argc, argv)
  97      cpp_reader *pfile;
  98      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               for (;;)
 169                 {
 170                   token = get_a_token (pfile);
 171                   if (token->type == CPP_OPEN_PAREN)
 172                     nesting++;
 173                   else if (token->type == CPP_CLOSE_PAREN)
 174                     {
 175                       nesting--;
 176                       if (nesting == 0)
 177                         break;
 178                     }
 179                   else if (token->type == CPP_EOF)
 180                     break;
 181                   else if (token->type == CPP_NAME
 182                            || token->type == CPP_ELLIPSIS)
 183                     have_arg_list = 1;
 184                 }
 185               recognized_function (&prev_id, token->line,
 186                                    (saw_inline ? 'I'
 187                                     : in_extern_C_brace || current_extern_C
 188                                     ? 'F' : 'f'), have_arg_list);
 189               token = get_a_token (pfile);
 190               if (token->type == CPP_OPEN_BRACE)
 191                 {
 192                   /* skip body of (normally) inline function */
 193                   skip_to_closing_brace (pfile);
 194                   goto new_statement;
 195                 }
 196
 197               /* skip a possible __attribute__ or throw expression after the
 198                  parameter list */
 199               while (token->type != CPP_SEMICOLON && token->type != CPP_EOF)
 200                 token = get_a_token (pfile);
 201               goto new_statement;
 202             }
 203           break;
 204         case CPP_NAME:
 205           /* "inline" and "extern" are recognized but skipped */
 206           if (cpp_ideq (token, "inline"))
 207             {
 208               saw_inline = 1;
 209             }
 210           else if (cpp_ideq (token, "extern"))
 211             {
 212               saw_extern = 1;
 213               token = get_a_token (pfile);
 214               if (token->type == CPP_STRING
 215                   && token->val.str.len == 1
 216                   && token->val.str.text[0] == 'C')
 217                 {
 218                   current_extern_C = 1;
 219                   token = get_a_token (pfile);
 220                   if (token->type == CPP_OPEN_BRACE)
 221                     {
 222                       brace_nesting++;
 223                       extern_C_braces[extern_C_braces_length++]
 224                         = brace_nesting;
 225                       goto new_statement;
 226                     }
 227                 }
 228               else
 229                 continue;
 230               break;
 231             }
 232           /* This may be the name of a variable or function.  */
 233           prev_id = *token;
 234           break;
 235         }
 236       token = get_a_token (pfile);
 237     }
 238 }