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