src/system.h

   1 /* System-dependent definitions for Bison.
   2
   3    Copyright (C) 2000-2007, 2009-2015, 2018-2021 Free Software
   4    Foundation, Inc.
   5
   6    This program is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation, either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef BISON_SYSTEM_H
  20 # define BISON_SYSTEM_H
  21
  22 /* flex 2.5.31 gratuitously defines macros like INT8_MIN.  But this
  23    runs afoul of pre-C99 compilers that have <inttypes.h> or
  24    <stdint.h>, which are included below if available.  It also runs
  25    afoul of pre-C99 compilers that define these macros in <limits.h>.  */
  26 # if ! defined __STDC_VERSION__ || __STDC_VERSION__ < 199901
  27 #  undef INT8_MIN
  28 #  undef INT16_MIN
  29 #  undef INT32_MIN
  30 #  undef INT8_MAX
  31 #  undef INT16_MAX
  32 #  undef UINT8_MAX
  33 #  undef INT32_MAX
  34 #  undef UINT16_MAX
  35 #  undef UINT32_MAX
  36 # endif
  37
  38 # include <limits.h>
  39 # include <stddef.h>
  40 # include <stdlib.h>
  41 # include <string.h>
  42
  43 # define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array))
  44 # define STREQ(L, R)  (strcmp(L, R) == 0)
  45 # define STRNEQ(L, R) (!STREQ(L, R))
  46
  47 /* Just like strncmp, but the second argument must be a literal string
  48    and you don't specify the length.  */
  49 # define STRNCMP_LIT(S, Literal)                        \
  50   strncmp (S, "" Literal "", sizeof (Literal) - 1)
  51
  52 /* Whether Literal is a prefix of S.  */
  53 # define STRPREFIX_LIT(Literal, S)              \
  54   (STRNCMP_LIT (S, Literal) == 0)
  55
  56 # include <unistd.h>
  57 # include <inttypes.h>
  58
  59 # ifndef UINTPTR_MAX
  60 /* This isn't perfect, but it's good enough for Bison, which needs
  61    only to hash pointers.  */
  62 typedef size_t uintptr_t;
  63 # endif
  64
  65 /* Version mismatch. */
  66 # define EX_MISMATCH 63
  67
  68 /*---------.
  69 | Gnulib.  |
  70 `---------*/
  71
  72 # include <unlocked-io.h>
  73 # include <verify.h>
  74 # include <xalloc.h>
  75
  76 // Clang and ICC like to pretend they are GCC.
  77 # if defined __GNUC__ && !defined __clang__ && !defined __ICC
  78 #  define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
  79 # endif
  80
  81 // See https://lists.gnu.org/r/bug-bison/2019-10/msg00061.html
  82 // and https://trac.macports.org/ticket/59927.
  83 # if defined GCC_VERSION && 405 <= GCC_VERSION
  84 #  define IGNORE_TYPE_LIMITS_BEGIN \
  85      _Pragma ("GCC diagnostic push") \
  86      _Pragma ("GCC diagnostic ignored \"-Wtype-limits\"")
  87 #  define IGNORE_TYPE_LIMITS_END \
  88      _Pragma ("GCC diagnostic pop")
  89 # else
  90 #  define IGNORE_TYPE_LIMITS_BEGIN
  91 #  define IGNORE_TYPE_LIMITS_END
  92 # endif
  93
  94
  95 /*-----------------.
  96 | GCC extensions.  |
  97 `-----------------*/
  98
  99 /* Use PACIFY_CC to indicate that Code is unimportant to the logic of Bison
 100    but that it is necessary for suppressing compiler warnings.  For example,
 101    Code might be a variable initializer that's always overwritten before the
 102    variable is used.
 103
 104    PACIFY_CC is intended to be useful only as a comment as it does not alter
 105    Code.  It is tempting to redefine PACIFY_CC so that it will suppress Code
 106    when configuring without --enable-gcc-warnings.  However, that would mean
 107    that, for maintainers, Bison would compile with potentially less warnings
 108    and safer logic than it would for users.  Due to the overhead of M4,
 109    suppressing Code is unlikely to offer any significant improvement in
 110    Bison's performance anyway.  */
 111 # define PACIFY_CC(Code) Code
 112
 113 # include <attribute.h>
 114
 115
 116 /*------.
 117 | NLS.  |
 118 `------*/
 119
 120 # include <locale.h>
 121
 122 # include <gettext.h>
 123 # define _(Msgid)  gettext (Msgid)
 124 # define N_(Msgid) (Msgid)
 125
 126
 127 /*-----------.
 128 | Booleans.  |
 129 `-----------*/
 130
 131 # include <stdbool.h>
 132
 133
 134 /*-----------.
 135 | Integers.  |
 136 `-----------*/
 137
 138 static inline int
 139 min_int (int a, int b)
 140 {
 141   return a < b ? a : b;
 142 }
 143
 144 static inline int
 145 max_int (int a, int b)
 146 {
 147   return a >= b ? a : b;
 148 }
 149
 150
 151 /*-------------.
 152 | Assertions.  |
 153 `-------------*/
 154
 155 /* In the past, Bison defined aver to simply invoke abort in the case of
 156    a failed assertion.  The rationale was that <assert.h>'s assertions
 157    were too heavyweight and could be disabled too easily.  See
 158    discussions at
 159    <https://lists.gnu.org/r/bison-patches/2006-01/msg00080.html>
 160    <https://lists.gnu.org/r/bison-patches/2006-09/msg00111.html>.
 161
 162    However, normal assert output can be helpful during development and
 163    in bug reports from users.  Moreover, it's not clear now that
 164    <assert.h>'s assertions are significantly heavyweight.  Finally, if
 165    users want to experiment with disabling assertions, it's debatable
 166    whether it's our responsibility to stop them.  See discussion
 167    starting at
 168    <https://lists.gnu.org/r/bison-patches/2009-09/msg00013.html>.
 169
 170    For now, we use assert but we call it aver throughout Bison in case
 171    we later wish to try another scheme.
 172 */
 173 # include <assert.h>
 174 # define aver assert
 175
 176
 177 /*-----------.
 178 | Obstacks.  |
 179 `-----------*/
 180
 181 # define obstack_chunk_alloc xmalloc
 182 # define obstack_chunk_free  free
 183 # include <obstack.h>
 184
 185 /* String-grow: append Str to Obs.  */
 186
 187 # define obstack_sgrow(Obs, Str) \
 188   obstack_grow (Obs, Str, strlen (Str))
 189
 190 /* Output Str escaped to be a string.
 191
 192    For instance "\"foo\"" -> "\\\"foo\\\"".  */
 193
 194 # define obstack_backslash(Obs, Str)                    \
 195   do {                                                  \
 196     char const *p__;                                    \
 197     for (p__ = Str; *p__; p__++)                        \
 198       switch (*p__)                                     \
 199         {                                               \
 200         case '"':  obstack_sgrow (Obs, "\\\""); break;  \
 201         case '\\': obstack_sgrow (Obs, "\\\\"); break;  \
 202         default:   obstack_1grow (Obs, *p__);   break;  \
 203         }                                               \
 204   } while (0)
 205
 206
 207 /* Output Str escaped for our postprocessing (i.e., escape M4 special
 208    characters).
 209
 210    For instance "[foo]" -> "@{foo@}", "$$" -> "$][$][". */
 211
 212 # define obstack_escape(Obs, Str)                       \
 213   do {                                                  \
 214     char const *p__;                                    \
 215     for (p__ = Str; *p__; p__++)                        \
 216       switch (*p__)                                     \
 217         {                                               \
 218         case '$': obstack_sgrow (Obs, "$]["); break;    \
 219         case '@': obstack_sgrow (Obs, "@@" ); break;    \
 220         case '[': obstack_sgrow (Obs, "@{" ); break;    \
 221         case ']': obstack_sgrow (Obs, "@}" ); break;    \
 222         default:  obstack_1grow (Obs, *p__ ); break;    \
 223         }                                               \
 224   } while (0)
 225
 226
 227 /* Output Str both quoted for M4 (i.e., embed in [[...]]), and escaped
 228    for our postprocessing (i.e., escape M4 special characters).  If
 229    Str is empty (or NULL), output "[]" instead of "[[]]" as it makes
 230    M4 programming easier (m4_ifval can be used).
 231
 232    For instance "[foo]" -> "[[@{foo@}]]", "$$" -> "[[$][$][]]".  */
 233
 234 # define obstack_quote(Obs, Str)                \
 235   do {                                          \
 236     char const* obstack_quote_p = Str;          \
 237     if (obstack_quote_p && obstack_quote_p[0])  \
 238       {                                         \
 239         obstack_sgrow (Obs, "[[");              \
 240         obstack_escape (Obs, obstack_quote_p);  \
 241         obstack_sgrow (Obs, "]]");              \
 242       }                                         \
 243     else                                        \
 244       obstack_sgrow (Obs, "[]");                \
 245   } while (0)
 246
 247
 248 /* Append the ending 0, finish Obs, and return the string.  */
 249
 250 # define obstack_finish0(Obs)                                   \
 251   (obstack_1grow (Obs, '\0'), (char *) obstack_finish (Obs))
 252
 253
 254 /*-----------------------------------------.
 255 | Extensions to use for the output files.  |
 256 `-----------------------------------------*/
 257
 258 # ifndef OUTPUT_EXT
 259 #  define OUTPUT_EXT ".output"
 260 # endif
 261
 262 # ifndef TAB_EXT
 263 #  define TAB_EXT ".tab"
 264 # endif
 265
 266
 267
 268 /*---------------------.
 269 | Free a linked list.  |
 270 `---------------------*/
 271
 272 # define LIST_FREE(Type, List)                  \
 273   do {                                          \
 274     Type *_node, *_next;                        \
 275     for (_node = List; _node; _node = _next)    \
 276       {                                         \
 277         _next = _node->next;                    \
 278         free (_node);                           \
 279       }                                         \
 280   } while (0)
 281
 282 #endif  /* ! BISON_SYSTEM_H */