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       cpp_pop_buffer (pfile);
 117       if (CPP_BUFFER (pfile) == NULL)
 118         return 0;
 119
 120       goto new_statement;
 121     }
 122   if (token.type == CPP_SEMICOLON)
 123     goto new_statement;
 124   if (token.type != CPP_NAME)
 125     goto new_statement;
 126
 127   prev_id.type = CPP_EOF;
 128   for (;;)
 129     {
 130       switch (token.type)
 131         {
 132         default:
 133           goto handle_statement;
 134         case CPP_MULT:
 135         case CPP_AND:
 136           /* skip */
 137           break;
 138
 139         case CPP_COMMA:
 140         case CPP_SEMICOLON:
 141           if (prev_id.type != CPP_EOF && saw_extern)
 142             {
 143               recognized_extern (&prev_id);
 144             }
 145           if (token.type == CPP_COMMA)
 146             break;
 147           /* ... fall through ...  */
 148         case CPP_OPEN_BRACE:  case CPP_CLOSE_BRACE:
 149           goto new_statement;
 150
 151         case CPP_EOF:
 152           cpp_pop_buffer (pfile);
 153           if (CPP_BUFFER (pfile) == NULL)
 154             return 0;
 155           break;
 156
 157         case CPP_OPEN_PAREN:
 158           /* Looks like this is the start of a formal parameter list.  */
 159           if (prev_id.type != CPP_EOF)
 160             {
 161               int nesting = 1;
 162               int have_arg_list = 0;
 163               for (;;)
 164                 {
 165                   cpp_get_token (pfile, &token);
 166                   if (token.type == CPP_OPEN_PAREN)
 167                     nesting++;
 168                   else if (token.type == CPP_CLOSE_PAREN)
 169                     {
 170                       nesting--;
 171                       if (nesting == 0)
 172                         break;
 173                     }
 174                   else if (token.type == CPP_EOF)
 175                     break;
 176                   else if (token.type == CPP_NAME
 177                            || token.type == CPP_ELLIPSIS)
 178                     have_arg_list = 1;
 179                 }
 180               recognized_function (&prev_id,
 181                                    cpp_get_line (pfile)->line,
 182                                    (saw_inline ? 'I'
 183                                     : in_extern_C_brace || current_extern_C
 184                                     ? 'F' : 'f'), have_arg_list);
 185               cpp_get_token (pfile, &token);
 186               if (token.type == CPP_OPEN_BRACE)
 187                 {
 188                   /* skip body of (normally) inline function */
 189                   skip_to_closing_brace (pfile);
 190                   goto new_statement;
 191                 }
 192               if (token.type == CPP_SEMICOLON)
 193                 goto new_statement;
 194             }
 195           break;
 196         case CPP_NAME:
 197           /* "inline" and "extern" are recognized but skipped */
 198           if (cpp_ideq (&token, "inline"))
 199             {
 200               saw_inline = 1;
 201             }
 202           else if (cpp_ideq (&token, "extern"))
 203             {
 204               saw_extern = 1;
 205               cpp_get_token (pfile, &token);
 206               if (token.type == CPP_STRING
 207                   && token.val.str.len == 1
 208                   && token.val.str.text[0] == 'C')
 209                 {
 210                   current_extern_C = 1;
 211                   cpp_get_token (pfile, &token);
 212                   if (token.type == CPP_OPEN_BRACE)
 213                     {
 214                       brace_nesting++;
 215                       extern_C_braces[extern_C_braces_length++]
 216                         = brace_nesting;
 217                       goto new_statement;
 218                     }
 219                 }
 220               else
 221                 continue;
 222               break;
 223             }
 224           /* This may be the name of a variable or function.  */
 225           prev_id = token;
 226           break;
 227         }
 228       cpp_get_token (pfile, &token);
 229     }
 230 }