* doc/extend.texi (Arrays and pointers implementation): Document

[pf3gnuchains/gcc-fork.git] / gcc / c-lex.c

/* Lexical analyzer for C and Objective C.
   Copyright (C) 1987, 1988, 1989, 1992, 1994, 1995, 1996, 1997
   1998, 1999, 2000 Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC 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 2, or (at your option)
any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"

#include "rtl.h"
#include "expr.h"
#include "tree.h"
#include "input.h"
#include "output.h"
#include "c-lex.h"
#include "c-tree.h"
#include "flags.h"
#include "timevar.h"
#include "cpplib.h"
#include "c-pragma.h"
#include "toplev.h"
#include "intl.h"
#include "tm_p.h"
#include "splay-tree.h"
#include "debug.h"

/* MULTIBYTE_CHARS support only works for native compilers.
   ??? Ideally what we want is to model widechar support after
   the current floating point support.  */
#ifdef CROSS_COMPILE
#undef MULTIBYTE_CHARS
#endif

#ifdef MULTIBYTE_CHARS
#include "mbchar.h"
#include <locale.h>
#endif /* MULTIBYTE_CHARS */
#ifndef GET_ENVIRONMENT
#define GET_ENVIRONMENT(ENV_VALUE,ENV_NAME) ((ENV_VALUE) = getenv (ENV_NAME))
#endif

/* The input filename as understood by CPP, where "" represents stdin.  */
static const char *cpp_filename;

/* The current line map.  */
static struct line_map *map;

/* We may keep statistics about how long which files took to compile.  */
static int header_time, body_time;
static splay_tree file_info_tree;

/* Cause the `yydebug' variable to be defined.  */
#define YYDEBUG 1

/* File used for outputting assembler code.  */
extern FILE *asm_out_file;

#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE TYPE_PRECISION (wchar_type_node)

/* Number of bytes in a wide character.  */
#define WCHAR_BYTES (WCHAR_TYPE_SIZE / BITS_PER_UNIT)

int indent_level;        /* Number of { minus number of }.  */
int pending_lang_change; /* If we need to switch languages - C++ only */
int c_header_level;      /* depth in C headers - C++ only */

/* Nonzero tells yylex to ignore \ in string constants.  */
static int ignore_escape_flag;

static void parse_float         PARAMS ((PTR));
static tree lex_number          PARAMS ((const char *, unsigned int));
static tree lex_string          PARAMS ((const char *, unsigned int, int));
static tree lex_charconst       PARAMS ((const cpp_token *));
static void update_header_times PARAMS ((const char *));
static int dump_one_header      PARAMS ((splay_tree_node, void *));
static void cb_ident            PARAMS ((cpp_reader *, unsigned int,
                                         const cpp_string *));
static void cb_file_change    PARAMS ((cpp_reader *, const cpp_file_change *));
static void cb_def_pragma       PARAMS ((cpp_reader *, unsigned int));
static void cb_define           PARAMS ((cpp_reader *, unsigned int,
                                         cpp_hashnode *));
static void cb_undef            PARAMS ((cpp_reader *, unsigned int,
                                         cpp_hashnode *));
\f
const char *
init_c_lex (filename)
     const char *filename;
{
  struct cpp_callbacks *cb;
  struct c_fileinfo *toplevel;

  /* Set up filename timing.  Must happen before cpp_start_read.  */
  file_info_tree = splay_tree_new ((splay_tree_compare_fn)strcmp,
                                   0,
                                   (splay_tree_delete_value_fn)free);
  toplevel = get_fileinfo ("<top level>");
  if (flag_detailed_statistics)
    {
      header_time = 0;
      body_time = get_run_time ();
      toplevel->time = body_time;
    }
  
#ifdef MULTIBYTE_CHARS
  /* Change to the native locale for multibyte conversions.  */
  setlocale (LC_CTYPE, "");
  GET_ENVIRONMENT (literal_codeset, "LANG");
#endif

  cb = cpp_get_callbacks (parse_in);

  cb->ident = cb_ident;
  cb->file_change = cb_file_change;
  cb->def_pragma = cb_def_pragma;

  /* Set the debug callbacks if we can use them.  */
  if (debug_info_level == DINFO_LEVEL_VERBOSE
      && (write_symbols == DWARF_DEBUG || write_symbols == DWARF2_DEBUG))
    {
      cb->define = cb_define;
      cb->undef = cb_undef;
    }


  if (filename == 0 || !strcmp (filename, "-"))
    filename = "stdin", cpp_filename = "";
  else
    cpp_filename = filename;

  /* Start it at 0.  */
  lineno = 0;

  return filename;
}

/* A thin wrapper around the real parser that initializes the 
   integrated preprocessor after debug output has been initialized.  */

int
yyparse()
{
  if (! cpp_start_read (parse_in, cpp_filename))
    return 1;                   /* cpplib has emitted an error.  */

  return yyparse_1();
}

struct c_fileinfo *
get_fileinfo (name)
     const char *name;
{
  splay_tree_node n;
  struct c_fileinfo *fi;

  n = splay_tree_lookup (file_info_tree, (splay_tree_key) name);
  if (n)
    return (struct c_fileinfo *) n->value;

  fi = (struct c_fileinfo *) xmalloc (sizeof (struct c_fileinfo));
  fi->time = 0;
  fi->interface_only = 0;
  fi->interface_unknown = 1;
  splay_tree_insert (file_info_tree, (splay_tree_key) name,
                     (splay_tree_value) fi);
  return fi;
}

static void
update_header_times (name)
     const char *name;
{
  /* Changing files again.  This means currently collected time
     is charged against header time, and body time starts back at 0.  */
  if (flag_detailed_statistics)
    {
      int this_time = get_run_time ();
      struct c_fileinfo *file = get_fileinfo (name);
      header_time += this_time - body_time;
      file->time += this_time - body_time;
      body_time = this_time;
    }
}

static int
dump_one_header (n, dummy)
     splay_tree_node n;
     void *dummy ATTRIBUTE_UNUSED;
{
  print_time ((const char *) n->key,
              ((struct c_fileinfo *) n->value)->time);
  return 0;
}

void
dump_time_statistics ()
{
  struct c_fileinfo *file = get_fileinfo (input_filename);
  int this_time = get_run_time ();
  file->time += this_time - body_time;

  fprintf (stderr, "\n******\n");
  print_time ("header files (total)", header_time);
  print_time ("main file (total)", this_time - body_time);
  fprintf (stderr, "ratio = %g : 1\n",
           (double)header_time / (double)(this_time - body_time));
  fprintf (stderr, "\n******\n");

  splay_tree_foreach (file_info_tree, dump_one_header, 0);
}

/* Not yet handled: #pragma, #define, #undef.
   No need to deal with linemarkers under normal conditions.  */

static void
cb_ident (pfile, line, str)
     cpp_reader *pfile ATTRIBUTE_UNUSED;
     unsigned int line ATTRIBUTE_UNUSED;
     const cpp_string *str ATTRIBUTE_UNUSED;
{
#ifdef ASM_OUTPUT_IDENT
  if (! flag_no_ident)
    {
      /* Convert escapes in the string.  */
      tree value = lex_string ((const char *)str->text, str->len, 0);
      ASM_OUTPUT_IDENT (asm_out_file, TREE_STRING_POINTER (value));
    }
#endif
}

static void
cb_file_change (pfile, fc)
     cpp_reader *pfile ATTRIBUTE_UNUSED;
     const cpp_file_change *fc;
{
  unsigned int from_line = SOURCE_LINE (fc->map - 1, fc->line - 1);

  if (fc->reason == LC_ENTER)
    {
      /* Don't stack the main buffer on the input stack;
         we already did in compile_file.  */
      if (MAIN_FILE_P (fc->map))
        main_input_filename = fc->map->to_file;
      else
        {
          lineno = from_line;
          push_srcloc (fc->map->to_file, 1);
          input_file_stack->indent_level = indent_level;
          (*debug_hooks->start_source_file) (lineno, fc->map->to_file);
#ifndef NO_IMPLICIT_EXTERN_C
          if (c_header_level)
            ++c_header_level;
          else if (fc->externc)
            {
              c_header_level = 1;
              ++pending_lang_change;
            }
#endif
        }
    }
  else if (fc->reason == LC_LEAVE)
    {
      /* Popping out of a file.  */
      if (input_file_stack->next)
        {
#ifndef NO_IMPLICIT_EXTERN_C
          if (c_header_level && --c_header_level == 0)
            {
              if (fc->externc)
                warning ("badly nested C headers from preprocessor");
              --pending_lang_change;
            }
#endif
#if 0
          if (indent_level != input_file_stack->indent_level)
            {
              warning_with_file_and_line
                (input_filename, lineno,
                 "This file contains more '%c's than '%c's.",
                 indent_level > input_file_stack->indent_level ? '{' : '}',
                 indent_level > input_file_stack->indent_level ? '}' : '{');
            }
#endif
          pop_srcloc ();
          (*debug_hooks->end_source_file) (from_line);
        }
      else
        error ("leaving more files than we entered");
    }

  update_header_times (fc->map->to_file);
  map = fc->map;
  in_system_header = fc->sysp != 0;
  input_filename = map->to_file;
  lineno = SOURCE_LINE (map, fc->line);

  /* Hook for C++.  */
  extract_interface_info ();
}

static void
cb_def_pragma (pfile, line)
     cpp_reader *pfile;
     unsigned int line;
{
  /* Issue a warning message if we have been asked to do so.  Ignore
     unknown pragmas in system headers unless an explicit
     -Wunknown-pragmas has been given.  */
  if (warn_unknown_pragmas > in_system_header)
    {
      const unsigned char *space, *name = 0;
      cpp_token s;

      cpp_get_token (pfile, &s);
      space = cpp_token_as_text (pfile, &s);
      cpp_get_token (pfile, &s);
      if (s.type == CPP_NAME)
        name = cpp_token_as_text (pfile, &s);

      lineno = SOURCE_LINE (map, line);
      if (name)
        warning ("ignoring #pragma %s %s", space, name);
      else
        warning ("ignoring #pragma %s", space);
    }
}

/* #define callback for DWARF and DWARF2 debug info.  */
static void
cb_define (pfile, line, node)
     cpp_reader *pfile;
     unsigned int line;
     cpp_hashnode *node;
{
  (*debug_hooks->define) (SOURCE_LINE (map, line),
                          (const char *) cpp_macro_definition (pfile, node));
}

/* #undef callback for DWARF and DWARF2 debug info.  */
static void
cb_undef (pfile, line, node)
     cpp_reader *pfile ATTRIBUTE_UNUSED;
     unsigned int line;
     cpp_hashnode *node;
{
  (*debug_hooks->undef) (SOURCE_LINE (map, line),
                         (const char *) NODE_NAME (node));
}

#if 0 /* not yet */
/* Returns nonzero if C is a universal-character-name.  Give an error if it
   is not one which may appear in an identifier, as per [extendid].

   Note that extended character support in identifiers has not yet been
   implemented.  It is my personal opinion that this is not a desirable
   feature.  Portable code cannot count on support for more than the basic
   identifier character set.  */

static inline int
is_extended_char (c)
     int c;
{
#ifdef TARGET_EBCDIC
  return 0;
#else
  /* ASCII.  */
  if (c < 0x7f)
    return 0;

  /* None of the valid chars are outside the Basic Multilingual Plane (the
     low 16 bits).  */
  if (c > 0xffff)
    {
      error ("universal-character-name '\\U%08x' not valid in identifier", c);
      return 1;
    }
  
  /* Latin */
  if ((c >= 0x00c0 && c <= 0x00d6)
      || (c >= 0x00d8 && c <= 0x00f6)
      || (c >= 0x00f8 && c <= 0x01f5)
      || (c >= 0x01fa && c <= 0x0217)
      || (c >= 0x0250 && c <= 0x02a8)
      || (c >= 0x1e00 && c <= 0x1e9a)
      || (c >= 0x1ea0 && c <= 0x1ef9))
    return 1;

  /* Greek */
  if ((c == 0x0384)
      || (c >= 0x0388 && c <= 0x038a)
      || (c == 0x038c)
      || (c >= 0x038e && c <= 0x03a1)
      || (c >= 0x03a3 && c <= 0x03ce)
      || (c >= 0x03d0 && c <= 0x03d6)
      || (c == 0x03da)
      || (c == 0x03dc)
      || (c == 0x03de)
      || (c == 0x03e0)
      || (c >= 0x03e2 && c <= 0x03f3)
      || (c >= 0x1f00 && c <= 0x1f15)
      || (c >= 0x1f18 && c <= 0x1f1d)
      || (c >= 0x1f20 && c <= 0x1f45)
      || (c >= 0x1f48 && c <= 0x1f4d)
      || (c >= 0x1f50 && c <= 0x1f57)
      || (c == 0x1f59)
      || (c == 0x1f5b)
      || (c == 0x1f5d)
      || (c >= 0x1f5f && c <= 0x1f7d)
      || (c >= 0x1f80 && c <= 0x1fb4)
      || (c >= 0x1fb6 && c <= 0x1fbc)
      || (c >= 0x1fc2 && c <= 0x1fc4)
      || (c >= 0x1fc6 && c <= 0x1fcc)
      || (c >= 0x1fd0 && c <= 0x1fd3)
      || (c >= 0x1fd6 && c <= 0x1fdb)
      || (c >= 0x1fe0 && c <= 0x1fec)
      || (c >= 0x1ff2 && c <= 0x1ff4)
      || (c >= 0x1ff6 && c <= 0x1ffc))
    return 1;

  /* Cyrillic */
  if ((c >= 0x0401 && c <= 0x040d)
      || (c >= 0x040f && c <= 0x044f)
      || (c >= 0x0451 && c <= 0x045c)
      || (c >= 0x045e && c <= 0x0481)
      || (c >= 0x0490 && c <= 0x04c4)
      || (c >= 0x04c7 && c <= 0x04c8)
      || (c >= 0x04cb && c <= 0x04cc)
      || (c >= 0x04d0 && c <= 0x04eb)
      || (c >= 0x04ee && c <= 0x04f5)
      || (c >= 0x04f8 && c <= 0x04f9))
    return 1;

  /* Armenian */
  if ((c >= 0x0531 && c <= 0x0556)
      || (c >= 0x0561 && c <= 0x0587))
    return 1;

  /* Hebrew */
  if ((c >= 0x05d0 && c <= 0x05ea)
      || (c >= 0x05f0 && c <= 0x05f4))
    return 1;

  /* Arabic */
  if ((c >= 0x0621 && c <= 0x063a)
      || (c >= 0x0640 && c <= 0x0652)
      || (c >= 0x0670 && c <= 0x06b7)
      || (c >= 0x06ba && c <= 0x06be)
      || (c >= 0x06c0 && c <= 0x06ce)
      || (c >= 0x06e5 && c <= 0x06e7))
    return 1;

  /* Devanagari */
  if ((c >= 0x0905 && c <= 0x0939)
      || (c >= 0x0958 && c <= 0x0962))
    return 1;

  /* Bengali */
  if ((c >= 0x0985 && c <= 0x098c)
      || (c >= 0x098f && c <= 0x0990)
      || (c >= 0x0993 && c <= 0x09a8)
      || (c >= 0x09aa && c <= 0x09b0)
      || (c == 0x09b2)
      || (c >= 0x09b6 && c <= 0x09b9)
      || (c >= 0x09dc && c <= 0x09dd)
      || (c >= 0x09df && c <= 0x09e1)
      || (c >= 0x09f0 && c <= 0x09f1))
    return 1;

  /* Gurmukhi */
  if ((c >= 0x0a05 && c <= 0x0a0a)
      || (c >= 0x0a0f && c <= 0x0a10)
      || (c >= 0x0a13 && c <= 0x0a28)
      || (c >= 0x0a2a && c <= 0x0a30)
      || (c >= 0x0a32 && c <= 0x0a33)
      || (c >= 0x0a35 && c <= 0x0a36)
      || (c >= 0x0a38 && c <= 0x0a39)
      || (c >= 0x0a59 && c <= 0x0a5c)
      || (c == 0x0a5e))
    return 1;

  /* Gujarati */
  if ((c >= 0x0a85 && c <= 0x0a8b)
      || (c == 0x0a8d)
      || (c >= 0x0a8f && c <= 0x0a91)
      || (c >= 0x0a93 && c <= 0x0aa8)
      || (c >= 0x0aaa && c <= 0x0ab0)
      || (c >= 0x0ab2 && c <= 0x0ab3)
      || (c >= 0x0ab5 && c <= 0x0ab9)
      || (c == 0x0ae0))
    return 1;

  /* Oriya */
  if ((c >= 0x0b05 && c <= 0x0b0c)
      || (c >= 0x0b0f && c <= 0x0b10)
      || (c >= 0x0b13 && c <= 0x0b28)
      || (c >= 0x0b2a && c <= 0x0b30)
      || (c >= 0x0b32 && c <= 0x0b33)
      || (c >= 0x0b36 && c <= 0x0b39)
      || (c >= 0x0b5c && c <= 0x0b5d)
      || (c >= 0x0b5f && c <= 0x0b61))
    return 1;

  /* Tamil */
  if ((c >= 0x0b85 && c <= 0x0b8a)
      || (c >= 0x0b8e && c <= 0x0b90)
      || (c >= 0x0b92 && c <= 0x0b95)
      || (c >= 0x0b99 && c <= 0x0b9a)
      || (c == 0x0b9c)
      || (c >= 0x0b9e && c <= 0x0b9f)
      || (c >= 0x0ba3 && c <= 0x0ba4)
      || (c >= 0x0ba8 && c <= 0x0baa)
      || (c >= 0x0bae && c <= 0x0bb5)
      || (c >= 0x0bb7 && c <= 0x0bb9))
    return 1;

  /* Telugu */
  if ((c >= 0x0c05 && c <= 0x0c0c)
      || (c >= 0x0c0e && c <= 0x0c10)
      || (c >= 0x0c12 && c <= 0x0c28)
      || (c >= 0x0c2a && c <= 0x0c33)
      || (c >= 0x0c35 && c <= 0x0c39)
      || (c >= 0x0c60 && c <= 0x0c61))
    return 1;

  /* Kannada */
  if ((c >= 0x0c85 && c <= 0x0c8c)
      || (c >= 0x0c8e && c <= 0x0c90)
      || (c >= 0x0c92 && c <= 0x0ca8)
      || (c >= 0x0caa && c <= 0x0cb3)
      || (c >= 0x0cb5 && c <= 0x0cb9)
      || (c >= 0x0ce0 && c <= 0x0ce1))
    return 1;

  /* Malayalam */
  if ((c >= 0x0d05 && c <= 0x0d0c)
      || (c >= 0x0d0e && c <= 0x0d10)
      || (c >= 0x0d12 && c <= 0x0d28)
      || (c >= 0x0d2a && c <= 0x0d39)
      || (c >= 0x0d60 && c <= 0x0d61))
    return 1;

  /* Thai */
  if ((c >= 0x0e01 && c <= 0x0e30)
      || (c >= 0x0e32 && c <= 0x0e33)
      || (c >= 0x0e40 && c <= 0x0e46)
      || (c >= 0x0e4f && c <= 0x0e5b))
    return 1;

  /* Lao */
  if ((c >= 0x0e81 && c <= 0x0e82)
      || (c == 0x0e84)
      || (c == 0x0e87)
      || (c == 0x0e88)
      || (c == 0x0e8a)
      || (c == 0x0e0d)
      || (c >= 0x0e94 && c <= 0x0e97)
      || (c >= 0x0e99 && c <= 0x0e9f)
      || (c >= 0x0ea1 && c <= 0x0ea3)
      || (c == 0x0ea5)
      || (c == 0x0ea7)
      || (c == 0x0eaa)
      || (c == 0x0eab)
      || (c >= 0x0ead && c <= 0x0eb0)
      || (c == 0x0eb2)
      || (c == 0x0eb3)
      || (c == 0x0ebd)
      || (c >= 0x0ec0 && c <= 0x0ec4)
      || (c == 0x0ec6))
    return 1;

  /* Georgian */
  if ((c >= 0x10a0 && c <= 0x10c5)
      || (c >= 0x10d0 && c <= 0x10f6))
    return 1;

  /* Hiragana */
  if ((c >= 0x3041 && c <= 0x3094)
      || (c >= 0x309b && c <= 0x309e))
    return 1;

  /* Katakana */
  if ((c >= 0x30a1 && c <= 0x30fe))
    return 1;

  /* Bopmofo */
  if ((c >= 0x3105 && c <= 0x312c))
    return 1;

  /* Hangul */
  if ((c >= 0x1100 && c <= 0x1159)
      || (c >= 0x1161 && c <= 0x11a2)
      || (c >= 0x11a8 && c <= 0x11f9))
    return 1;

  /* CJK Unified Ideographs */
  if ((c >= 0xf900 && c <= 0xfa2d)
      || (c >= 0xfb1f && c <= 0xfb36)
      || (c >= 0xfb38 && c <= 0xfb3c)
      || (c == 0xfb3e)
      || (c >= 0xfb40 && c <= 0xfb41)
      || (c >= 0xfb42 && c <= 0xfb44)
      || (c >= 0xfb46 && c <= 0xfbb1)
      || (c >= 0xfbd3 && c <= 0xfd3f)
      || (c >= 0xfd50 && c <= 0xfd8f)
      || (c >= 0xfd92 && c <= 0xfdc7)
      || (c >= 0xfdf0 && c <= 0xfdfb)
      || (c >= 0xfe70 && c <= 0xfe72)
      || (c == 0xfe74)
      || (c >= 0xfe76 && c <= 0xfefc)
      || (c >= 0xff21 && c <= 0xff3a)
      || (c >= 0xff41 && c <= 0xff5a)
      || (c >= 0xff66 && c <= 0xffbe)
      || (c >= 0xffc2 && c <= 0xffc7)
      || (c >= 0xffca && c <= 0xffcf)
      || (c >= 0xffd2 && c <= 0xffd7)
      || (c >= 0xffda && c <= 0xffdc)
      || (c >= 0x4e00 && c <= 0x9fa5))
    return 1;

  error ("universal-character-name '\\u%04x' not valid in identifier", c);
  return 1;
#endif
}

/* Add the UTF-8 representation of C to the token_buffer.  */

static void
utf8_extend_token (c)
     int c;
{
  int shift, mask;

  if      (c <= 0x0000007f)
    {
      extend_token (c);
      return;
    }
  else if (c <= 0x000007ff)
    shift = 6, mask = 0xc0;
  else if (c <= 0x0000ffff)
    shift = 12, mask = 0xe0;
  else if (c <= 0x001fffff)
    shift = 18, mask = 0xf0;
  else if (c <= 0x03ffffff)
    shift = 24, mask = 0xf8;
  else
    shift = 30, mask = 0xfc;

  extend_token (mask | (c >> shift));
  do
    {
      shift -= 6;
      extend_token ((unsigned char) (0x80 | (c >> shift)));
    }
  while (shift);
}
#endif

#if 0
struct try_type
{
  tree *node_var;
  char unsigned_flag;
  char long_flag;
  char long_long_flag;
};

struct try_type type_sequence[] =
{
  { &integer_type_node, 0, 0, 0},
  { &unsigned_type_node, 1, 0, 0},
  { &long_integer_type_node, 0, 1, 0},
  { &long_unsigned_type_node, 1, 1, 0},
  { &long_long_integer_type_node, 0, 1, 1},
  { &long_long_unsigned_type_node, 1, 1, 1}
};
#endif /* 0 */
\f
struct pf_args
{
  /* Input */
  const char *str;
  int fflag;
  int lflag;
  int base;
  /* Output */
  int conversion_errno;
  REAL_VALUE_TYPE value;
  tree type;
};
 
static void
parse_float (data)
  PTR data;
{
  struct pf_args * args = (struct pf_args *) data;
  const char *typename;

  args->conversion_errno = 0;
  args->type = double_type_node;
  typename = "double";

  /* The second argument, machine_mode, of REAL_VALUE_ATOF
     tells the desired precision of the binary result
     of decimal-to-binary conversion.  */

  if (args->fflag)
    {
      if (args->lflag)
        error ("both 'f' and 'l' suffixes on floating constant");

      args->type = float_type_node;
      typename = "float";
    }
  else if (args->lflag)
    {
      args->type = long_double_type_node;
      typename = "long double";
    }
  else if (flag_single_precision_constant)
    {
      args->type = float_type_node;
      typename = "float";
    }

  errno = 0;
  if (args->base == 16)
    args->value = REAL_VALUE_HTOF (args->str, TYPE_MODE (args->type));
  else
    args->value = REAL_VALUE_ATOF (args->str, TYPE_MODE (args->type));

  args->conversion_errno = errno;
  /* A diagnostic is required here by some ISO C testsuites.
     This is not pedwarn, because some people don't want
     an error for this.  */
  if (REAL_VALUE_ISINF (args->value) && pedantic)
    warning ("floating point number exceeds range of '%s'", typename);
}
 
int
c_lex (value)
     tree *value;
{
  cpp_token tok;
  enum cpp_ttype type;

  retry:
  timevar_push (TV_CPP);
  cpp_get_token (parse_in, &tok);
  timevar_pop (TV_CPP);

  /* The C++ front end does horrible things with the current line
     number.  To ensure an accurate line number, we must reset it
     every time we return a token.  */
  lineno = SOURCE_LINE (map, cpp_get_line (parse_in)->line);

  *value = NULL_TREE;
  type = tok.type;
  switch (type)
    {
    case CPP_OPEN_BRACE:  indent_level++;  break;
    case CPP_CLOSE_BRACE: indent_level--;  break;

    /* Issue this error here, where we can get at tok.val.c.  */
    case CPP_OTHER:
      if (ISGRAPH (tok.val.c))
        error ("stray '%c' in program", tok.val.c);
      else
        error ("stray '\\%o' in program", tok.val.c);
      goto retry;
      
    case CPP_NAME:
      *value = HT_IDENT_TO_GCC_IDENT (HT_NODE (tok.val.node));
      break;

    case CPP_NUMBER:
      *value = lex_number ((const char *)tok.val.str.text, tok.val.str.len);
      break;

    case CPP_CHAR:
    case CPP_WCHAR:
      *value = lex_charconst (&tok);
      break;

    case CPP_STRING:
    case CPP_WSTRING:
      *value = lex_string ((const char *)tok.val.str.text,
                           tok.val.str.len, tok.type == CPP_WSTRING);
      break;

      /* These tokens should not be visible outside cpplib.  */
    case CPP_HEADER_NAME:
    case CPP_COMMENT:
    case CPP_MACRO_ARG:
      abort ();

    default: break;
    }

  return type;
}

#define ERROR(msgid) do { error(msgid); goto syntax_error; } while(0)

static tree
lex_number (str, len)
     const char *str;
     unsigned int len;
{
  int base = 10;
  int count = 0;
  int largest_digit = 0;
  int numdigits = 0;
  int overflow = 0;
  int c;
  tree value;
  const char *p;
  enum anon1 { NOT_FLOAT = 0, AFTER_POINT, AFTER_EXPON } floatflag = NOT_FLOAT;
  
  /* We actually store only HOST_BITS_PER_CHAR bits in each part.
     The code below which fills the parts array assumes that a host
     int is at least twice as wide as a host char, and that 
     HOST_BITS_PER_WIDE_INT is an even multiple of HOST_BITS_PER_CHAR.
     Two HOST_WIDE_INTs is the largest int literal we can store.
     In order to detect overflow below, the number of parts (TOTAL_PARTS)
     must be exactly the number of parts needed to hold the bits
     of two HOST_WIDE_INTs.  */
#define TOTAL_PARTS ((HOST_BITS_PER_WIDE_INT / HOST_BITS_PER_CHAR) * 2)
  unsigned int parts[TOTAL_PARTS];
  
  /* Optimize for most frequent case.  */
  if (len == 1)
    {
      if (*str == '0')
        return integer_zero_node;
      else if (*str == '1')
        return integer_one_node;
      else
        return build_int_2 (*str - '0', 0);
    }

  for (count = 0; count < TOTAL_PARTS; count++)
    parts[count] = 0;

  /* len is known to be >1 at this point.  */
  p = str;

  if (len > 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
    {
      base = 16;
      p = str + 2;
    }
  /* The ISDIGIT check is so we are not confused by a suffix on 0.  */
  else if (str[0] == '0' && ISDIGIT (str[1]))
    {
      base = 8;
      p = str + 1;
    }

  do
    {
      c = *p++;

      if (c == '.')
        {
          if (floatflag == AFTER_POINT)
            ERROR ("too many decimal points in floating constant");
          else if (floatflag == AFTER_EXPON)
            ERROR ("decimal point in exponent - impossible!");
          else
            floatflag = AFTER_POINT;

          if (base == 8)
            base = 10;
        }
      else if (c == '_')
        /* Possible future extension: silently ignore _ in numbers,
           permitting cosmetic grouping - e.g. 0x8000_0000 == 0x80000000
           but somewhat easier to read.  Ada has this?  */
        ERROR ("underscore in number");
      else
        {
          int n;
          /* It is not a decimal point.
             It should be a digit (perhaps a hex digit).  */

          if (ISDIGIT (c))
            {
              n = c - '0';
            }
          else if (base <= 10 && (c == 'e' || c == 'E'))
            {
              base = 10;
              floatflag = AFTER_EXPON;
              break;
            }
          else if (base == 16 && (c == 'p' || c == 'P'))
            {
              floatflag = AFTER_EXPON;
              break;   /* start of exponent */
            }
          else if (base == 16 && c >= 'a' && c <= 'f')
            {
              n = c - 'a' + 10;
            }
          else if (base == 16 && c >= 'A' && c <= 'F')
            {
              n = c - 'A' + 10;
            }
          else
            {
              p--;
              break;  /* start of suffix */
            }

          if (n >= largest_digit)
            largest_digit = n;
          numdigits++;

          for (count = 0; count < TOTAL_PARTS; count++)
            {
              parts[count] *= base;
              if (count)
                {
                  parts[count]
                    += (parts[count-1] >> HOST_BITS_PER_CHAR);
                  parts[count-1]
                    &= (1 << HOST_BITS_PER_CHAR) - 1;
                }
              else
                parts[0] += n;
            }

          /* If the highest-order part overflows (gets larger than
             a host char will hold) then the whole number has 
             overflowed.  Record this and truncate the highest-order
             part.  */
          if (parts[TOTAL_PARTS - 1] >> HOST_BITS_PER_CHAR)
            {
              overflow = 1;
              parts[TOTAL_PARTS - 1] &= (1 << HOST_BITS_PER_CHAR) - 1;
            }
        }
    }
  while (p < str + len);

  /* This can happen on input like `int i = 0x;' */
  if (numdigits == 0)
    ERROR ("numeric constant with no digits");

  if (largest_digit >= base)
    ERROR ("numeric constant contains digits beyond the radix");

  if (floatflag != NOT_FLOAT)
    {
      tree type;
      int imag, fflag, lflag, conversion_errno;
      REAL_VALUE_TYPE real;
      struct pf_args args;
      char *copy;

      if (base == 16 && pedantic && !flag_isoc99)
        pedwarn ("floating constant may not be in radix 16");

      if (base == 16 && floatflag != AFTER_EXPON)
        ERROR ("hexadecimal floating constant has no exponent");

      /* Read explicit exponent if any, and put it in tokenbuf.  */
      if ((base == 10 && ((c == 'e') || (c == 'E')))
          || (base == 16 && (c == 'p' || c == 'P')))
        {
          if (p < str + len)
            c = *p++;
          if (p < str + len && (c == '+' || c == '-'))
            c = *p++;
          /* Exponent is decimal, even if string is a hex float.  */
          if (! ISDIGIT (c))
            ERROR ("floating constant exponent has no digits");
          while (p < str + len && ISDIGIT (c))
            c = *p++;
          if (! ISDIGIT (c))
            p--;
        }

      /* Copy the float constant now; we don't want any suffixes in the
         string passed to parse_float.  */
      copy = alloca (p - str + 1);
      memcpy (copy, str, p - str);
      copy[p - str] = '\0';

      /* Now parse suffixes.  */
      fflag = lflag = imag = 0;
      while (p < str + len)
        switch (*p++)
          {
          case 'f': case 'F':
            if (fflag)
              ERROR ("more than one 'f' suffix on floating constant");
            else if (warn_traditional && !in_system_header
                     && ! cpp_sys_macro_p (parse_in))
              warning ("traditional C rejects the 'f' suffix");

            fflag = 1;
            break;

          case 'l': case 'L':
            if (lflag)
              ERROR ("more than one 'l' suffix on floating constant");
            else if (warn_traditional && !in_system_header
                     && ! cpp_sys_macro_p (parse_in))
              warning ("traditional C rejects the 'l' suffix");

            lflag = 1;
            break;

          case 'i': case 'I':
          case 'j': case 'J':
            if (imag)
              ERROR ("more than one 'i' or 'j' suffix on floating constant");
            else if (pedantic)
              pedwarn ("ISO C forbids imaginary numeric constants");
            imag = 1;
            break;

          default:
            ERROR ("invalid suffix on floating constant");
          }

      /* Setup input for parse_float() */
      args.str = copy;
      args.fflag = fflag;
      args.lflag = lflag;
      args.base = base;

      /* Convert string to a double, checking for overflow.  */
      if (do_float_handler (parse_float, (PTR) &args))
        {
          /* Receive output from parse_float() */
          real = args.value;
        }
      else
          /* We got an exception from parse_float() */
          ERROR ("floating constant out of range");

      /* Receive output from parse_float() */
      conversion_errno = args.conversion_errno;
      type = args.type;
            
#ifdef ERANGE
      /* ERANGE is also reported for underflow,
         so test the value to distinguish overflow from that.  */
      if (conversion_errno == ERANGE && !flag_traditional && pedantic
          && (REAL_VALUES_LESS (dconst1, real)
              || REAL_VALUES_LESS (real, dconstm1)))
        warning ("floating point number exceeds range of 'double'");
#endif

      /* Create a node with determined type and value.  */
      if (imag)
        value = build_complex (NULL_TREE, convert (type, integer_zero_node),
                               build_real (type, real));
      else
        value = build_real (type, real);
    }
  else
    {
      tree trad_type, ansi_type, type;
      HOST_WIDE_INT high, low;
      int spec_unsigned = 0;
      int spec_long = 0;
      int spec_long_long = 0;
      int spec_imag = 0;
      int suffix_lu = 0;
      int warn = 0, i;

      trad_type = ansi_type = type = NULL_TREE;
      while (p < str + len)
        {
          c = *p++;
          switch (c)
            {
            case 'u': case 'U':
              if (spec_unsigned)
                error ("two 'u' suffixes on integer constant");
              else if (warn_traditional && !in_system_header
                       && ! cpp_sys_macro_p (parse_in))
                warning ("traditional C rejects the 'u' suffix");

              spec_unsigned = 1;
              if (spec_long)
                suffix_lu = 1;
              break;

            case 'l': case 'L':
              if (spec_long)
                {
                  if (spec_long_long)
                    error ("three 'l' suffixes on integer constant");
                  else if (suffix_lu)
                    error ("'lul' is not a valid integer suffix");
                  else if (c != spec_long)
                    error ("'Ll' and 'lL' are not valid integer suffixes");
                  else if (pedantic && ! flag_isoc99
                           && ! in_system_header && warn_long_long)
                    pedwarn ("ISO C89 forbids long long integer constants");
                  spec_long_long = 1;
                }
              spec_long = c;
              break;

            case 'i': case 'I': case 'j': case 'J':
              if (spec_imag)
                error ("more than one 'i' or 'j' suffix on integer constant");
              else if (pedantic)
                pedwarn ("ISO C forbids imaginary numeric constants");
              spec_imag = 1;
              break;

            default:
              ERROR ("invalid suffix on integer constant");
            }
        }

      /* If the literal overflowed, pedwarn about it now.  */
      if (overflow)
        {
          warn = 1;
          pedwarn ("integer constant is too large for this configuration of the compiler - truncated to %d bits", HOST_BITS_PER_WIDE_INT * 2);
        }

      /* This is simplified by the fact that our constant
         is always positive.  */

      high = low = 0;

      for (i = 0; i < HOST_BITS_PER_WIDE_INT / HOST_BITS_PER_CHAR; i++)
        {
          high |= ((HOST_WIDE_INT) parts[i + (HOST_BITS_PER_WIDE_INT
                                              / HOST_BITS_PER_CHAR)]
                   << (i * HOST_BITS_PER_CHAR));
          low |= (HOST_WIDE_INT) parts[i] << (i * HOST_BITS_PER_CHAR);
        }

      value = build_int_2 (low, high);
      TREE_TYPE (value) = long_long_unsigned_type_node;

      /* If warn_traditional, calculate both the ISO type and the
         traditional type, then see if they disagree.
         Otherwise, calculate only the type for the dialect in use.  */
      if (warn_traditional || flag_traditional)
        {
          /* Calculate the traditional type.  */
          /* Traditionally, any constant is signed; but if unsigned is
             specified explicitly, obey that.  Use the smallest size
             with the right number of bits, except for one special
             case with decimal constants.  */
          if (! spec_long && base != 10
              && int_fits_type_p (value, unsigned_type_node))
            trad_type = spec_unsigned ? unsigned_type_node : integer_type_node;
          /* A decimal constant must be long if it does not fit in
             type int.  I think this is independent of whether the
             constant is signed.  */
          else if (! spec_long && base == 10
                   && int_fits_type_p (value, integer_type_node))
            trad_type = spec_unsigned ? unsigned_type_node : integer_type_node;
          else if (! spec_long_long)
            trad_type = (spec_unsigned
                         ? long_unsigned_type_node
                         : long_integer_type_node);
          else if (int_fits_type_p (value,
                                    spec_unsigned 
                                    ? long_long_unsigned_type_node
                                    : long_long_integer_type_node)) 
            trad_type = (spec_unsigned
                         ? long_long_unsigned_type_node
                         : long_long_integer_type_node);
          else
            trad_type = (spec_unsigned
                         ? widest_unsigned_literal_type_node
                         : widest_integer_literal_type_node);
        }
      if (warn_traditional || ! flag_traditional)
        {
          /* Calculate the ISO type.  */
          if (! spec_long && ! spec_unsigned
              && int_fits_type_p (value, integer_type_node))
            ansi_type = integer_type_node;
          else if (! spec_long && (base != 10 || spec_unsigned)
                   && int_fits_type_p (value, unsigned_type_node))
            ansi_type = unsigned_type_node;
          else if (! spec_unsigned && !spec_long_long
                   && int_fits_type_p (value, long_integer_type_node))
            ansi_type = long_integer_type_node;
          else if (! spec_long_long
                   && int_fits_type_p (value, long_unsigned_type_node))
            ansi_type = long_unsigned_type_node;
          else if (! spec_unsigned
                   && int_fits_type_p (value, long_long_integer_type_node))
            ansi_type = long_long_integer_type_node;
          else if (int_fits_type_p (value, long_long_unsigned_type_node))
            ansi_type = long_long_unsigned_type_node;
          else if (! spec_unsigned
                   && int_fits_type_p (value, widest_integer_literal_type_node))
            ansi_type = widest_integer_literal_type_node;
          else
            ansi_type = widest_unsigned_literal_type_node;
        }

      type = flag_traditional ? trad_type : ansi_type;

      /* We assume that constants specified in a non-decimal
         base are bit patterns, and that the programmer really
         meant what they wrote.  */
      if (warn_traditional && !in_system_header
          && base == 10 && trad_type != ansi_type)
        {
          if (TYPE_PRECISION (trad_type) != TYPE_PRECISION (ansi_type))
            warning ("width of integer constant changes with -traditional");
          else if (TREE_UNSIGNED (trad_type) != TREE_UNSIGNED (ansi_type))
            warning ("integer constant is unsigned in ISO C, signed with -traditional");
          else
            warning ("width of integer constant may change on other systems with -traditional");
        }

      if (pedantic && !flag_traditional && (flag_isoc99 || !spec_long_long)
          && !warn
          && ((flag_isoc99
               ? TYPE_PRECISION (long_long_integer_type_node)
               : TYPE_PRECISION (long_integer_type_node)) < TYPE_PRECISION (type)))
        {
          warn = 1;
          pedwarn ("integer constant larger than the maximum value of %s",
                   (flag_isoc99
                    ? (TREE_UNSIGNED (type)
                       ? "an unsigned long long int"
                       : "a long long int")
                    : "an unsigned long int"));
        }

      if (base == 10 && ! spec_unsigned && TREE_UNSIGNED (type))
        warning ("decimal constant is so large that it is unsigned");

      if (spec_imag)
        {
          if (TYPE_PRECISION (type)
              <= TYPE_PRECISION (integer_type_node))
            value = build_complex (NULL_TREE, integer_zero_node,
                                   convert (integer_type_node, value));
          else
            ERROR ("complex integer constant is too wide for 'complex int'");
        }
      else if (flag_traditional && !int_fits_type_p (value, type))
        /* The traditional constant 0x80000000 is signed
           but doesn't fit in the range of int.
           This will change it to -0x80000000, which does fit.  */
        {
          TREE_TYPE (value) = unsigned_type (type);
          value = convert (type, value);
          TREE_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (value) = 0;
        }
      else
        TREE_TYPE (value) = type;

      /* If it's still an integer (not a complex), and it doesn't
         fit in the type we choose for it, then pedwarn.  */

      if (! warn
          && TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE
          && ! int_fits_type_p (value, TREE_TYPE (value)))
        pedwarn ("integer constant is larger than the maximum value for its type");
    }

  if (p < str + len)
    error ("missing white space after number '%.*s'", (int) (p - str), str);

  return value;

 syntax_error:
  return integer_zero_node;
}

static tree
lex_string (str, len, wide)
     const char *str;
     unsigned int len;
     int wide;
{
  tree value;
  char *buf = alloca ((len + 1) * (wide ? WCHAR_BYTES : 1));
  char *q = buf;
  const char *p = str, *limit = str + len;
  unsigned int c;
  unsigned width = wide ? WCHAR_TYPE_SIZE
                        : TYPE_PRECISION (char_type_node);

#ifdef MULTIBYTE_CHARS
  /* Reset multibyte conversion state.  */
  (void) local_mbtowc (NULL, NULL, 0);
#endif

  while (p < limit)
    {
#ifdef MULTIBYTE_CHARS
      wchar_t wc;
      int char_len;

      char_len = local_mbtowc (&wc, p, limit - p);
      if (char_len == -1)
        {
          warning ("Ignoring invalid multibyte character");
          char_len = 1;
          c = *p++;
        }
      else
        {
          p += char_len;
          c = wc;
        }
#else
      c = *p++;
#endif

      if (c == '\\' && !ignore_escape_flag)
        {
          unsigned int mask;

          if (width < HOST_BITS_PER_INT)
            mask = ((unsigned int) 1 << width) - 1;
          else
            mask = ~0;
          c = cpp_parse_escape (parse_in, (const unsigned char **) &p,
                                (const unsigned char *) limit,
                                mask, flag_traditional);
        }
        
      /* Add this single character into the buffer either as a wchar_t
         or as a single byte.  */
      if (wide)
        {
          unsigned charwidth = TYPE_PRECISION (char_type_node);
          unsigned bytemask = (1 << charwidth) - 1;
          int byte;

          for (byte = 0; byte < WCHAR_BYTES; ++byte)
            {
              int n;
              if (byte >= (int) sizeof (c))
                n = 0;
              else
                n = (c >> (byte * charwidth)) & bytemask;
              if (BYTES_BIG_ENDIAN)
                q[WCHAR_BYTES - byte - 1] = n;
              else
                q[byte] = n;
            }
          q += WCHAR_BYTES;
        }
      else
        {
          *q++ = c;
        }
    }

  /* Terminate the string value, either with a single byte zero
     or with a wide zero.  */

  if (wide)
    {
      memset (q, 0, WCHAR_BYTES);
      q += WCHAR_BYTES;
    }
  else
    {
      *q++ = '\0';
    }

  value = build_string (q - buf, buf);

  if (wide)
    TREE_TYPE (value) = wchar_array_type_node;
  else
    TREE_TYPE (value) = char_array_type_node;
  return value;
}

/* Converts a (possibly wide) character constant token into a tree.  */
static tree
lex_charconst (token)
     const cpp_token *token;
{
  HOST_WIDE_INT result;
  tree value;
  unsigned int chars_seen;
 
  result = cpp_interpret_charconst (parse_in, token, warn_multichar,
                                    flag_traditional, &chars_seen);
  if (token->type == CPP_WCHAR)
    {
      value = build_int_2 (result, 0);
      TREE_TYPE (value) = wchar_type_node;
    }
  else
    {
      if (result < 0)
        value = build_int_2 (result, -1);
      else
        value = build_int_2 (result, 0);
 
      /* In C, a character constant has type 'int'.
         In C++ 'char', but multi-char charconsts have type 'int'.  */
      if (c_language == clk_cplusplus && chars_seen <= 1)
        TREE_TYPE (value) = char_type_node;
      else
        TREE_TYPE (value) = integer_type_node;
    }
 
  return value;
}