src/flex-scanner.h

   1 /* Common parts between scan-code.l, scan-gram.l, and scan-skel.l.
   2
   3    Copyright (C) 2006, 2009-2015, 2018-2021 Free Software Foundation,
   4    Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  20
  21 #ifndef FLEX_PREFIX
  22 # error "FLEX_PREFIX not defined"
  23 #endif
  24
  25 /* Flex full version as a number.  */
  26 #define FLEX_VERSION                    \
  27   ((YY_FLEX_MAJOR_VERSION) * 1000000    \
  28    + (YY_FLEX_MINOR_VERSION) * 1000     \
  29    + (YY_FLEX_SUBMINOR_VERSION))
  30
  31 // Pacify warnings in yy_init_buffer (observed with Flex 2.6.4 and GCC
  32 // 6.4.0 and 7.3.0).
  33 //
  34 // ./src/scan-skel.c: In function 'skel_restart':
  35 // ./src/scan-skel.c:2035:20: error: potential null pointer dereference [-Werror=null-dereference]
  36 //   b->yy_fill_buffer = 1;
  37 //   ~~~~~~~~~~~~~~~~~~^~~
  38 // ./src/scan-skel.c:2031:19: error: potential null pointer dereference [-Werror=null-dereference]
  39 //   b->yy_input_file = file;
  40 //   ~~~~~~~~~~~~~~~~~^~~~~~
  41 #if defined __GNUC__ && ! defined __clang__ && 6 <= __GNUC__
  42 # pragma GCC diagnostic ignored "-Wnull-dereference"
  43 #endif
  44
  45 // Old versions of Flex (2.5.35) generate an incomplete documentation comment.
  46 //
  47 //  In file included from src/scan-code-c.c:3:
  48 //  src/scan-code.c:2198:21: error: empty paragraph passed to '@param' command
  49 //        [-Werror,-Wdocumentation]
  50 //   * @param line_number
  51 //     ~~~~~~~~~~~~~~~~~^
  52 //  1 error generated.
  53 #if FLEX_VERSION <= 20060000 && defined __clang__
  54 # pragma clang diagnostic ignored "-Wdocumentation"
  55 #endif
  56
  57 /* Pacify "gcc -Wmissing-prototypes" when flex 2.5.31 is used.  */
  58 #if FLEX_VERSION <= 2005031
  59 int   FLEX_PREFIX (get_lineno) (void);
  60 FILE *FLEX_PREFIX (get_in) (void);
  61 FILE *FLEX_PREFIX (get_out) (void);
  62 int   FLEX_PREFIX (get_leng) (void);
  63 char *FLEX_PREFIX (get_text) (void);
  64 void  FLEX_PREFIX (set_lineno) (int);
  65 void  FLEX_PREFIX (set_in) (FILE *);
  66 void  FLEX_PREFIX (set_out) (FILE *);
  67 int   FLEX_PREFIX (get_debug) (void);
  68 void  FLEX_PREFIX (set_debug) (int);
  69 int   FLEX_PREFIX (lex_destroy) (void);
  70 #endif
  71
  72 #define last_string    FLEX_PREFIX (last_string)
  73
  74 /* It seems to be a nice "feature" of Flex that one cannot use yytext,
  75    yyleng etc. when a prefix is given, since there is no longer a
  76    #define, but rather the token is actually changed in the output.
  77    However, this is not true for Flex 2.5.4.  */
  78 #ifndef yyleng
  79 # define yyleng  FLEX_PREFIX (leng)
  80 #endif
  81 #ifndef yytext
  82 # define yytext  FLEX_PREFIX (text)
  83 #endif
  84
  85 /* Non-reentrant scanners generated by Flex 2.5.9 and later (and some earlier
  86    versions according to the Flex manual) leak memory if yylex_destroy is not
  87    invoked.  However, yylex_destroy is not defined before Flex 2.5.9, so give
  88    an implementation here that at least appears to work with Flex 2.5.4.  */
  89 #if FLEX_VERSION <= 2005009
  90 # define yylex_destroy() yy_delete_buffer (YY_CURRENT_BUFFER)
  91 #endif
  92
  93 /* OBSTACK_FOR_STRING -- Used to store all the characters that we need to
  94    keep (to construct ID, STRINGS etc.).  Use the following macros to
  95    use it.
  96
  97    Use STRING_GROW () to append what has just been matched, and
  98    STRING_FINISH () to end the string (it puts the ending 0).
  99    STRING_FINISH () also stores this string in LAST_STRING, which can be
 100    used, and which is used by STRING_FREE () to free the last string.  */
 101
 102 #ifndef FLEX_NO_OBSTACK
 103
 104 static struct obstack obstack_for_string;
 105
 106 # define STRING_GROW()                                  \
 107   obstack_grow (&obstack_for_string, yytext, yyleng)
 108
 109 # define STRING_FINISH()                                \
 110   (last_string = obstack_finish0 (&obstack_for_string))
 111
 112 # define STRING_1GROW(Char)                     \
 113   obstack_1grow (&obstack_for_string, Char)
 114
 115 # ifdef NDEBUG
 116 #  define STRING_FREE()                                 \
 117   obstack_free (&obstack_for_string, last_string)
 118 # else
 119 #  define STRING_FREE()                                  \
 120   do {                                                   \
 121     obstack_free (&obstack_for_string, last_string);     \
 122     last_string = NULL;                                  \
 123   } while (0)
 124 # endif
 125
 126 #endif