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
  28 int brace_nesting = 0;
  29
  30 /* The first extern_C_braces_length elements of extern_C_braces
  31    indicate the (brace nesting levels of) left braces that were
  32    prefixed by extern "C".  */
  33 int extern_C_braces_length = 0;
  34 char extern_C_braces[20];
  35 #define in_extern_C_brace (extern_C_braces_length>0)
  36
  37 /* True if the function declaration currently being scanned is
  38    prefixed by extern "C".  */
  39 int current_extern_C = 0;
  40
  41 static void
  42 skip_to_closing_brace (pfile)
  43      cpp_reader *pfile;
  44 {
  45   int nesting = 1;
  46   for (;;)
  47     {
  48       cpp_token tok;
  49       enum cpp_ttype token;
  50
  51       cpp_get_token (pfile, &tok);
  52       token = tok.type;
  53       if (token == CPP_EOF)
  54         break;
  55       if (token == CPP_OPEN_BRACE)
  56         nesting++;
  57       if (token == CPP_CLOSE_BRACE && --nesting == 0)
  58         break;
  59     }
  60 }
  61
  62 /* This function scans a C source file (actually, the output of cpp),
  63    reading from FP.  It looks for function declarations, and
  64    external variable declarations.
  65
  66    The following grammar (as well as some extra stuff) is recognized:
  67
  68    declaration:
  69      (decl-specifier)* declarator ("," declarator)* ";"
  70    decl-specifier:
  71      identifier
  72      keyword
  73      extern "C"
  74    declarator:
  75      (ptr-operator)* dname [ "(" argument-declaration-list ")" ]
  76    ptr-operator:
  77      ("*" | "&") ("const" | "volatile")*
  78    dname:
  79      identifier
  80
  81 Here dname is the actual name being declared.
  82 */
  83
  84 int
  85 scan_decls (pfile, argc, argv)
  86      cpp_reader *pfile;
  87      int argc ATTRIBUTE_UNUSED;
  88      char **argv ATTRIBUTE_UNUSED;
  89 {
  90   int saw_extern, saw_inline;
  91   cpp_token token, prev_id;
  92
  93  new_statement:
  94   cpp_get_token (pfile, &token);
  95
  96  handle_statement:
  97   current_extern_C = 0;
  98   saw_extern = 0;
  99   saw_inline = 0;
 100   if (token.type == CPP_OPEN_BRACE)
 101     {
 102       /* Pop an 'extern "C"' nesting level, if appropriate.  */
 103       if (extern_C_braces_length
 104           && extern_C_braces[extern_C_braces_length - 1] == brace_nesting)
 105         extern_C_braces_length--;
 106       brace_nesting--;
 107       goto new_statement;
 108     }
 109   if (token.type == CPP_OPEN_BRACE)
 110     {
 111       brace_nesting++;
 112       goto new_statement;
 113     }
 114   if (token.type == CPP_EOF)
 115     {
 116       if (cpp_pop_buffer (pfile) == 0)
 117         return 0;
 118
 119       goto new_statement;
 120     }
 121   if (token.type == CPP_SEMICOLON)
 122     goto new_statement;
 123   if (token.type != CPP_NAME)
 124     goto new_statement;
 125
 126   prev_id.type = CPP_EOF;
 127   for (;;)
 128     {
 129       switch (token.type)
 130         {
 131         default:
 132           goto handle_statement;
 133         case CPP_MULT:
 134         case CPP_AND:
 135           /* skip */
 136           break;
 137
 138         case CPP_COMMA:
 139         case CPP_SEMICOLON:
 140           if (prev_id.type != CPP_EOF && saw_extern)
 141             {
 142               recognized_extern (&prev_id);
 143             }
 144           if (token.type == CPP_COMMA)
 145             break;
 146           /* ... fall through ...  */
 147         case CPP_OPEN_BRACE:  case CPP_CLOSE_BRACE:
 148           goto new_statement;
 149
 150         case CPP_EOF:
 151           if (cpp_pop_buffer (pfile) == 0)
 152             return 0;
 153           break;
 154
 155         case CPP_OPEN_PAREN:
 156           /* Looks like this is the start of a formal parameter list.  */
 157           if (prev_id.type != CPP_EOF)
 158             {
 159               int nesting = 1;
 160               int have_arg_list = 0;
 161               for (;;)
 162                 {
 163                   cpp_get_token (pfile, &token);
 164                   if (token.type == CPP_OPEN_PAREN)
 165                     nesting++;
 166                   else if (token.type == CPP_CLOSE_PAREN)
 167                     {
 168                       nesting--;
 169                       if (nesting == 0)
 170                         break;
 171                     }
 172                   else if (token.type == CPP_EOF)
 173                     break;
 174                   else if (token.type == CPP_NAME
 175                            || token.type == CPP_ELLIPSIS)
 176                     have_arg_list = 1;
 177                 }
 178               recognized_function (&prev_id,
 179                                    cpp_get_line (pfile)->line,
 180                                    (saw_inline ? 'I'
 181                                     : in_extern_C_brace || current_extern_C
 182                                     ? 'F' : 'f'), have_arg_list);
 183               cpp_get_token (pfile, &token);
 184               if (token.type == CPP_OPEN_BRACE)
 185                 {
 186                   /* skip body of (normally) inline function */
 187                   skip_to_closing_brace (pfile);
 188                   goto new_statement;
 189                 }
 190               if (token.type == CPP_SEMICOLON)
 191                 goto new_statement;
 192             }
 193           break;
 194         case CPP_NAME:
 195           /* "inline" and "extern" are recognized but skipped */
 196           if (cpp_ideq (&token, "inline"))
 197             {
 198               saw_inline = 1;
 199             }
 200           else if (cpp_ideq (&token, "extern"))
 201             {
 202               saw_extern = 1;
 203               cpp_get_token (pfile, &token);
 204               if (token.type == CPP_STRING
 205                   && token.val.str.len == 1
 206                   && token.val.str.text[0] == 'C')
 207                 {
 208                   current_extern_C = 1;
 209                   cpp_get_token (pfile, &token);
 210                   if (token.type == CPP_OPEN_BRACE)
 211                     {
 212                       brace_nesting++;
 213                       extern_C_braces[extern_C_braces_length++]
 214                         = brace_nesting;
 215                       goto new_statement;
 216                     }
 217                 }
 218               else
 219                 continue;
 220               break;
 221             }
 222           /* This may be the name of a variable or function.  */
 223           prev_id = token;
 224           break;
 225         }
 226       cpp_get_token (pfile, &token);
 227     }
 228 }