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/* scan-decls.c - Extracts declarations from cpp output.

   Copyright (C) 1993, 1995, 1997, 1998,

   1999, 2000, 2003, 2004, 2007 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify it

   under the terms of the GNU General Public License as published by the

   Free Software Foundation; either version 3, or (at your option) any

   later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; see the file COPYING3.  If not see

   <http://www.gnu.org/licenses/>.

   Written by Per Bothner <bothner@cygnus.com>, July 1993.  */

#include "bconfig.h"

#include "system.h"

#include "coretypes.h"

#include "tm.h"

#include "cpplib.h"

#include "scan.h"

static void skip_to_closing_brace (cpp_reader *);

static const cpp_token *get_a_token (cpp_reader *);

int brace_nesting = 0;

/* The first extern_C_braces_length elements of extern_C_braces

   indicate the (brace nesting levels of) left braces that were

   prefixed by extern "C".  */

int extern_C_braces_length = 0;

/* 20 is not enough anymore on Solaris 9.  */

#define MAX_EXTERN_C_BRACES  200

char extern_C_braces[MAX_EXTERN_C_BRACES];

#define in_extern_C_brace (extern_C_braces_length>0)

/* True if the function declaration currently being scanned is

   prefixed by extern "C".  */

int current_extern_C = 0;

/* Get a token but skip padding.  */

static const cpp_token *

get_a_token (cpp_reader *pfile)

{

  for (;;)

    {

      const cpp_token *result = cpp_get_token (pfile);

      if (result->type != CPP_PADDING)

        return result;

    }

}

static void

skip_to_closing_brace (cpp_reader *pfile)

{

  int nesting = 1;

  for (;;)

    {

      enum cpp_ttype token = get_a_token (pfile)->type;

      if (token == CPP_EOF)

        break;

      if (token == CPP_OPEN_BRACE)

        nesting++;

      if (token == CPP_CLOSE_BRACE && --nesting == 0)

        break;

    }

}

/* This function scans a C source file (actually, the output of cpp),

   reading from FP.  It looks for function declarations, and

   external variable declarations.

   The following grammar (as well as some extra stuff) is recognized:

   declaration:

     (decl-specifier)* declarator ("," declarator)* ";"

   decl-specifier:

     identifier

     keyword

     extern "C"

   declarator:

     (ptr-operator)* dname [ "(" argument-declaration-list ")" ]

   ptr-operator:

     ("*" | "&") ("const" | "volatile")*

   dname:

     identifier

Here dname is the actual name being declared.

*/

int

scan_decls (cpp_reader *pfile, int argc ATTRIBUTE_UNUSED,

            char **argv ATTRIBUTE_UNUSED)

{

  int saw_extern, saw_inline;

  cpp_token prev_id;

  const cpp_token *token;

 new_statement:

  token = get_a_token (pfile);

 handle_statement:

  current_extern_C = 0;

  saw_extern = 0;

  saw_inline = 0;

  if (token->type == CPP_OPEN_BRACE)

    {

      /* Pop an 'extern "C"' nesting level, if appropriate.  */

      if (extern_C_braces_length

          && extern_C_braces[extern_C_braces_length - 1] == brace_nesting)

        extern_C_braces_length--;

      brace_nesting--;

      goto new_statement;

    }

  if (token->type == CPP_OPEN_BRACE)

    {

      brace_nesting++;

      goto new_statement;

    }

  if (token->type == CPP_EOF)

    return 0;

  if (token->type == CPP_SEMICOLON)

    goto new_statement;

  if (token->type != CPP_NAME)

    goto new_statement;

  prev_id.type = CPP_EOF;

  for (;;)

    {

      switch (token->type)

        {

        default:

          goto handle_statement;

        case CPP_MULT:

        case CPP_AND:

          /* skip */

          break;

        case CPP_COMMA:

        case CPP_SEMICOLON:

          if (prev_id.type != CPP_EOF && saw_extern)

            {

              recognized_extern (&prev_id);

            }

          if (token->type == CPP_COMMA)

            break;

          /* ... fall through ...  */

        case CPP_OPEN_BRACE:  case CPP_CLOSE_BRACE:

          goto new_statement;

        case CPP_EOF:

          return 0;

        case CPP_OPEN_PAREN:

          /* Looks like this is the start of a formal parameter list.  */

          if (prev_id.type != CPP_EOF)

            {

              int nesting = 1;

              int have_arg_list = 0;

              const struct line_map *map;

              unsigned int line;

              for (;;)

                {

                  token = get_a_token (pfile);

                  if (token->type == CPP_OPEN_PAREN)

                    nesting++;

                  else if (token->type == CPP_CLOSE_PAREN)

                    {

                      nesting--;

                      if (nesting == 0)

                        break;

                    }

                  else if (token->type == CPP_EOF)

                    break;

                  else if (token->type == CPP_NAME

                           || token->type == CPP_ELLIPSIS)

                    have_arg_list = 1;

                }

              map = linemap_lookup (&line_table, token->src_loc);

              line = SOURCE_LINE (map, token->src_loc);

              recognized_function (&prev_id, line,

                                   (saw_inline ? 'I'

                                    : in_extern_C_brace || current_extern_C

                                    ? 'F' : 'f'), have_arg_list);

              token = get_a_token (pfile);

              if (token->type == CPP_OPEN_BRACE)

                {

                  /* skip body of (normally) inline function */

                  skip_to_closing_brace (pfile);

                  goto new_statement;

                }

              /* skip a possible __attribute__ or throw expression after the

                 parameter list */

              while (token->type != CPP_SEMICOLON && token->type != CPP_EOF)

                token = get_a_token (pfile);

              if (token->type == CPP_EOF)

                return 0;

              goto new_statement;

            }

          break;

        case CPP_NAME:

          /* "inline" and "extern" are recognized but skipped */

          if (cpp_ideq (token, "inline"))

            {

              saw_inline = 1;

            }

          else if (cpp_ideq (token, "extern"))

            {

              saw_extern = 1;

              token = get_a_token (pfile);

              if (token->type == CPP_STRING

                  && token->val.str.len == 1

                  && token->val.str.text[0] == 'C')

                {

                  current_extern_C = 1;

                  token = get_a_token (pfile);

                  if (token->type == CPP_OPEN_BRACE)

                    {

                      brace_nesting++;

                      extern_C_braces[extern_C_braces_length++]

                        = brace_nesting;

                      if (extern_C_braces_length >= MAX_EXTERN_C_BRACES)

                        {

                          fprintf (stderr,

                                   "Internal error: out-of-bounds index\n");

                          exit (FATAL_EXIT_CODE);

                        }

                      goto new_statement;

                    }

                }

              else

                continue;

              break;

            }

          /* This may be the name of a variable or function.  */

          prev_id = *token;

          break;

        }

      token = get_a_token (pfile);

    }

}