libguile/gen-scmconfig.c

   1 /* Copyright (C) 2003-2013 Free Software Foundation, Inc.
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public License
   5  * as published by the Free Software Foundation; either version 3 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301 USA
  17  */
  18
  19 /**********************************************************************
  20
  21   Description of Guile's public config header mechanics:
  22   -----------------------------------------------------
  23
  24   Guile has four core headers:
  25
  26     config.h: Guile's private automatically generated configuration
  27       header -- generated by configure.in and autoheader.  *NOT*
  28       installed during "make install" and so may not be referred to by
  29       any public headers.
  30
  31     libguile/_scm.h: Guile's private core header.  _scm.h is not
  32       installed.  It's only visible to the libguile sources
  33       themselves, and it includes config.h, the private config header.
  34       Among other things this file provides a place to make decisions
  35       based on the information gathered in config.h.
  36
  37     libguile/scmconfig.h: Guile's public automatically generated
  38       configuration header -- generated at build time by concatenating
  39       the contents of libguile/scmconfig.h.top with the output from
  40       libguile/gen-scmconfig.  gen-scmconfig bases its output on the
  41       information in the private config.h header, the contents of
  42       gen-scmconfig.h (which is created by configure.in from
  43       gen-scmconfig.h.in), and the information provided in this file,
  44       gen-scmconfig.c.
  45
  46     libguile/__scm.h: Guile's public core header.  This file is
  47       installed and publically visible.  It includes
  48       libguile/scmconfig.h, the public config header and provides a
  49       place to make decisions based on the information gathered in
  50       scmconfig.h to define things that other headers can depend on.
  51
  52    Notes and guidelines:
  53
  54    - use 1 and 0 for public #defines instead of "def and undef",
  55      i.e. use #define SCM_HAVE_FOO rather than just not defining
  56      SCM_HAVE_FOO whenever possible.  See GNU Coding Guidelines for
  57      rationale.  The only notable non-deprecated exception to this rule
  58      is GUILE_DEBUG which does not follow this convention in order to
  59      retain backward compatibility.
  60
  61    - in the code below, be *VERY* careful not to use or rely on any
  62      runtime-dynamic information below.  For example, you cannot use
  63      sizeof (FOO), but must use static information like SIZEOF_BAR
  64      (from config.h) or SCM_SIZEOF_BAZ (from scmconfig.h).  This is
  65      because the gcc that is compiling gen-scmconfig.c and/or the
  66      machine that is running gen-scmconfig may not be the same
  67      compiler and/or hardware that will eventually be running Guile.
  68      (i.e. keep the cross-compilation case in mind).
  69
  70    - try to avoid adding names to the public namespace when possible.
  71      Note in the code below, that in a number of cases, we detect a
  72      feature and based on that, we decide whether or not to print
  73      anything at all.  This decreases the extraneous #defines and
  74      #ifdefery that we require in scmconfig.h
  75
  76    - try to avoid adding any duplicate definitions to config.h and
  77      scmconfig.h.  i.e. have just SCM_ENABLE_ELISP in scmconfig.h
  78      rather than ENABLE_ELISP in config.h and SCM_ENABLE_ELISP in
  79      scmconfig.h.
  80
  81    - in cases where you need to communicate information from
  82      configure.in to gen-scmconfig.c, don't add an AC_DEFINE unless
  83      you need it for other purposes.  Just add a suitable SCM_I_GSC_*
  84      variable to configure.in, set the value, AC_SUBST the value, and
  85      add an appropriate line to gen-scmconfig.h.in.  All gen-scmconfig
  86      related AC_SUBST vars should be prefixed with SCM_I_GSC_.
  87
  88    - make sure that anything that we explicitly typedef publically is
  89      prefixed with scm_t_.  i.e. we used to typedef long to ptrdiff_t
  90      if we didn't detect ptrdiff_t, but this has been changed so that
  91      we typedef scm_t_ptrdiff instead so that we won't conflict with
  92      any non-guile header definitions of the same type.  For types
  93      like intptr_t and uintptr_t which we just try to detect and don't
  94      actually define, it's fine not to have a corresponding scm_t_
  95      type.
  96
  97    - we now use SCM_SIZEOF_FOO != 0 rather than SCM_HAVE_FOO for any
  98      cases where the size might actually vary.
  99
 100    Rationales (not finished):
 101
 102      Why do we use a C program here rather than AC_OUTPUT_COMMANDS?
 103      --------------------------------------------------------------
 104
 105      The main reason is that there are some values we would need
 106      access to at AC_OUTPUT_COMMANDs that are determined by configure
 107      but are not available at AC_OUTPUT time.  The values are *only*
 108      available via config.h.  We use gen-scmconfig so we can see those
 109      values and make decisions based on their settings.
 110
 111      Why have gen-scmconfig.h.in?
 112      ----------------------------
 113
 114      Without that header, we could end up needing multiple aliases for
 115      public settings like SCM_ENABLE_ELISP.  We can't define
 116      SCM_ENABLE_ELISP in config.h since that header is private and any
 117      definition in scmconfig.h would conflict (#ifndef might be
 118      possible but runs the risk of conflicting directives), so a
 119      likely solution would be to AC_DEFINE([SCM_I_ENABLE_ELISP]), and
 120      then use SCM_I_ENABLE_ELISP in gen-scmconfig via config.h to
 121      determine whether or not to #define SCM_ENABLE_ELISP, but this
 122      leaves us with two #defined symbols for each public setting --
 123      better to just have one value (public or private) that all code
 124      uses.
 125
 126      Having this header means we can AC_SUBST a value like
 127      SCM_I_GSC_ENABLE_ELISP and then set it in here via AC_OUTPUT
 128      substitutions, and gen-scmconfig can use that definition to
 129      determine whether or not to #define SCM_ENABLE_ELISP when
 130      generating scmconfig.h, and we end up with nothing extraneous
 131      added to config.h.
 132
 133  **********************************************************************/
 134
 135 #ifdef HAVE_CONFIG_H
 136 #  include <config.h>
 137 #endif
 138
 139 #include <libguile/gen-scmconfig.h>
 140
 141 #include <stdio.h>
 142 #include <string.h>
 143
 144 #define pf printf
 145
 146 int
 147 main (int argc, char *argv[])
 148 {
 149   pf ("/* This file is automatically generated --"
 150       " see configure.in for details */\n"
 151       "\n"
 152       "#ifndef SCM_SCMCONFIG_H\n"
 153       "#define SCM_SCMCONFIG_H\n");
 154
 155   /*** various important headers ***/
 156   pf ("\n");
 157   pf ("/* Important headers */\n");
 158   if (SCM_I_GSC_NEEDS_STDINT_H)
 159     pf ("#include <stdint.h>\n");
 160   if (SCM_I_GSC_NEEDS_INTTYPES_H)
 161     pf ("#include <inttypes.h>\n");
 162
 163 #ifdef HAVE_LIMITS_H
 164   pf ("#include <limits.h>\n");
 165 #else
 166   pf ("/* limits.h not available */\n");
 167 #endif
 168
 169 #if HAVE_SYS_TIME_H
 170   pf ("#include <sys/time.h>\n");
 171 #else
 172   pf ("/* sys/time.h not available */\n");
 173 #endif
 174
 175 #if HAVE_TIME_H
 176   pf ("#include <time.h>\n");
 177 #else
 178   pf ("/* time.h not available */\n");
 179 #endif
 180
 181   pf("\n");
 182 #ifdef STDC_HEADERS
 183   pf ("#define SCM_HAVE_STDC_HEADERS 1 /* 0 or 1 */\n");
 184   pf ("#include <stdlib.h>\n");
 185 # ifdef HAVE_SYS_TYPES_H
 186   pf ("#include <sys/types.h>\n");
 187 # endif
 188 # ifdef HAVE_SYS_STDTYPES_H
 189   pf ("#include <sys/stdtypes.h>\n");
 190 # endif
 191   pf ("#include <stddef.h>\n");
 192 #else /* STDC_HEADERS */
 193   pf ("#define SCM_HAVE_STDC_HEADERS 0 /* 0 or 1 */");
 194 #endif /* def STDC_HEADERS */
 195
 196   pf("\n");
 197 #ifdef HAVE_SYS_SELECT_H
 198   pf ("#define SCM_HAVE_SYS_SELECT_H 1 /* 0 or 1 */\n");
 199 #else
 200   pf ("#define SCM_HAVE_SYS_SELECT_H 0 /* 0 or 1 */\n");
 201 #endif
 202
 203 #ifdef HAVE_WINSOCK2_H
 204   pf ("#define SCM_HAVE_WINSOCK2_H 1 /* 0 or 1 */\n");
 205 #else
 206   pf ("#define SCM_HAVE_WINSOCK2_H 0 /* 0 or 1 */\n");
 207 #endif
 208
 209
 210   /*** GUILE_DEBUG (defined or undefined) ***/
 211   pf ("\n");
 212   pf ("/* Define to include various undocumented debugging functions. */\n");
 213   if (SCM_I_GSC_GUILE_DEBUG)
 214     pf ("#define GUILE_DEBUG 1 /* defined or undefined */\n");
 215   else
 216     pf ("/* #undef GUILE_DEBUG */\n");
 217
 218   /*** SCM_ENABLE_DEPRECATED (0 or 1) ***/
 219   pf ("\n");
 220   pf ("/* Set to 1 if you want to enable deprecated features. */\n");
 221   pf ("/* (value will be 0 or 1). */\n");
 222   pf ("#define SCM_ENABLE_DEPRECATED %d\n", SCM_I_GSC_ENABLE_DEPRECATED);
 223
 224   /*** SCM_STACK_GROWS_UP (0 or 1) ***/
 225   pf ("\n");
 226   pf ("/* Set to 1 if the stack grows up, 0 otherwise. */\n");
 227   pf ("#define SCM_STACK_GROWS_UP %d /* 0 or 1 */\n",
 228       SCM_I_GSC_STACK_GROWS_UP);
 229
 230   /*** SCM_C_INLINE (defined to appropriate string or undefined) ***/
 231   pf ("\n");
 232   pf ("/* C compiler's syntax for inline functions if any,\n"
 233       "   otherwise undefined. */\n");
 234   if (SCM_I_GSC_C_INLINE)
 235     pf ("#define SCM_C_INLINE %s\n", SCM_I_GSC_C_INLINE);
 236   else
 237     pf ("/* #undef SCM_C_INLINE */\n");
 238
 239   pf ("\n");
 240   pf ("/* Standard types. */\n");
 241
 242   pf ("/* These are always defined */\n");
 243   pf ("#define SCM_SIZEOF_CHAR %d\n", SIZEOF_CHAR);
 244   pf ("#define SCM_SIZEOF_UNSIGNED_CHAR %d\n", SIZEOF_UNSIGNED_CHAR);
 245   pf ("#define SCM_SIZEOF_SHORT %d\n", SIZEOF_SHORT);
 246   pf ("#define SCM_SIZEOF_UNSIGNED_SHORT %d\n", SIZEOF_UNSIGNED_SHORT);
 247   pf ("#define SCM_SIZEOF_LONG %d\n", SIZEOF_LONG);
 248   pf ("#define SCM_SIZEOF_UNSIGNED_LONG %d\n", SIZEOF_UNSIGNED_LONG);
 249   pf ("#define SCM_SIZEOF_INT %d\n", SIZEOF_INT);
 250   pf ("#define SCM_SIZEOF_UNSIGNED_INT %d\n", SIZEOF_UNSIGNED_INT);
 251   pf ("#define SCM_SIZEOF_SIZE_T %d\n", SIZEOF_SIZE_T);
 252
 253   pf ("\n");
 254   pf ("/* Size of (unsigned) long long or 0 if not available (scm_t_*64 may\n"
 255       "   be more likely to be what you want */\n");
 256   pf ("#define SCM_SIZEOF_LONG_LONG %d\n", SIZEOF_LONG_LONG);
 257   pf ("#define SCM_SIZEOF_UNSIGNED_LONG_LONG %d\n", SIZEOF_UNSIGNED_LONG_LONG);
 258
 259   pf ("\n");
 260   pf ("/* These are always defined. */\n");
 261   pf ("typedef %s scm_t_int8;\n", SCM_I_GSC_T_INT8);
 262   pf ("typedef %s scm_t_uint8;\n", SCM_I_GSC_T_UINT8);
 263   pf ("typedef %s scm_t_int16;\n", SCM_I_GSC_T_INT16);
 264   pf ("typedef %s scm_t_uint16;\n", SCM_I_GSC_T_UINT16);
 265   pf ("typedef %s scm_t_int32;\n", SCM_I_GSC_T_INT32);
 266   pf ("typedef %s scm_t_uint32;\n", SCM_I_GSC_T_UINT32);
 267   pf ("typedef %s scm_t_intmax;\n", SCM_I_GSC_T_INTMAX);
 268   pf ("typedef %s scm_t_uintmax;\n", SCM_I_GSC_T_UINTMAX);
 269   pf ("typedef %s scm_t_intptr;\n", SCM_I_GSC_T_INTPTR);
 270   pf ("typedef %s scm_t_uintptr;\n", SCM_I_GSC_T_UINTPTR);
 271
 272   if (0 == strcmp ("intmax_t", SCM_I_GSC_T_INTMAX))
 273     pf ("#define SCM_SIZEOF_INTMAX %d\n", SIZEOF_INTMAX_T);
 274   else if (0 == strcmp ("long long", SCM_I_GSC_T_INTMAX))
 275     pf ("#define SCM_SIZEOF_INTMAX %d\n", SIZEOF_LONG_LONG);
 276   else if (0 == strcmp ("__int64", SCM_I_GSC_T_INTMAX))
 277     pf ("#define SCM_SIZEOF_INTMAX %d\n", SIZEOF___INT64);
 278   else
 279     return 1;
 280
 281   pf ("\n");
 282   pf ("#define SCM_HAVE_T_INT64 1 /* 0 or 1 */\n");
 283   pf ("typedef %s scm_t_int64;\n", SCM_I_GSC_T_INT64);
 284   pf ("#define SCM_HAVE_T_UINT64 1 /* 0 or 1 */\n");
 285   pf ("typedef %s scm_t_uint64;\n", SCM_I_GSC_T_UINT64);
 286
 287   pf ("\n");
 288   pf ("/* scm_t_ptrdiff and size, always defined -- defined to long if\n"
 289       "   platform doesn't have ptrdiff_t. */\n");
 290   pf ("typedef %s scm_t_ptrdiff;\n", SCM_I_GSC_T_PTRDIFF);
 291   if (0 == strcmp ("long", SCM_I_GSC_T_PTRDIFF))
 292     pf ("#define SCM_SIZEOF_SCM_T_PTRDIFF %d\n", SIZEOF_LONG);
 293   else
 294     pf ("#define SCM_SIZEOF_SCM_T_PTRDIFF %d\n", SIZEOF_PTRDIFF_T);
 295
 296   pf ("\n");
 297   pf ("/* Size of intptr_t or 0 if not available */\n");
 298   pf ("#define SCM_SIZEOF_INTPTR_T %d\n", SIZEOF_INTPTR_T);
 299   pf ("/* Size of uintptr_t or 0 if not available */\n");
 300   pf ("#define SCM_SIZEOF_UINTPTR_T %d\n", SIZEOF_UINTPTR_T);
 301
 302   pf ("\n");
 303   pf ("/* same as POSIX \"struct timespec\" -- always defined */\n");
 304 #ifdef HAVE_SYSTEM_STRUCT_TIMESPEC
 305   pf ("typedef struct timespec scm_t_timespec;\n");
 306 #else
 307   pf ("/* POSIX.4 structure for a time value.  This is like a `struct timeval'"
 308       "   but has nanoseconds instead of microseconds.  */\n");
 309   pf ("typedef struct\n"
 310       "{\n"
 311       "  long int tv_sec;               /* Seconds.  */\n"
 312       "  long int tv_nsec;              /* Nanoseconds.  */\n"
 313       "} scm_t_timespec;\n");
 314 #endif
 315
 316   pf ("\n");
 317   pf ("/*** Threading model (scmconfig.h support not finished) ***/\n");
 318
 319   pf ("/* Define to 1 if using pthread multithreading. */\n");
 320   pf ("#define SCM_USE_PTHREAD_THREADS %d /* 0 or 1 */\n",
 321       SCM_I_GSC_USE_PTHREAD_THREADS);
 322
 323   pf ("/* Define to 1 if using one-thread 'multi'threading. */\n");
 324   pf ("#define SCM_USE_NULL_THREADS %d /* 0 or 1 */\n",
 325       SCM_I_GSC_USE_NULL_THREADS);
 326
 327   pf ("/* Define to 1 if need braces around PTHREAD_ONCE_INIT (for Solaris). */\n");
 328   pf ("#define SCM_NEED_BRACES_ON_PTHREAD_ONCE_INIT %d /* 0 or 1 */\n",
 329       SCM_I_GSC_NEED_BRACES_ON_PTHREAD_ONCE_INIT);
 330
 331   pf ("/* Define to 1 if need braces around PTHREAD_MUTEX_INITIALIZER\n"
 332       "   (for IRIX with GCC)  */\n");
 333   pf ("#define SCM_NEED_BRACES_ON_PTHREAD_MUTEX_INITIALIZER %d /* 0 or 1 */\n",
 334       SCM_I_GSC_NEED_BRACES_ON_PTHREAD_MUTEX_INITIALIZER);
 335
 336 #ifdef HAVE_GC_PTHREAD_CANCEL
 337   pf ("#define SCM_HAVE_GC_PTHREAD_CANCEL 1 /* 0 or 1 */\n");
 338 #else
 339   pf ("#define SCM_HAVE_GC_PTHREAD_CANCEL 0 /* 0 or 1 */\n");
 340 #endif
 341
 342 #ifdef HAVE_GC_PTHREAD_EXIT
 343   pf ("#define SCM_HAVE_GC_PTHREAD_EXIT 1 /* 0 or 1 */\n");
 344 #else
 345   pf ("#define SCM_HAVE_GC_PTHREAD_EXIT 0 /* 0 or 1 */\n");
 346 #endif
 347
 348 #ifdef HAVE_GC_PTHREAD_SIGMASK
 349   pf ("#define SCM_HAVE_GC_PTHREAD_SIGMASK 1 /* 0 or 1 */\n");
 350 #else
 351   pf ("#define SCM_HAVE_GC_PTHREAD_SIGMASK 0 /* 0 or 1 */\n");
 352 #endif
 353
 354   pf ("\n\n/*** File system access ***/\n");
 355
 356   pf ("/* Define to 1 if `struct dirent64' is available.  */\n");
 357   pf ("#define SCM_HAVE_STRUCT_DIRENT64 %d /* 0 or 1 */\n",
 358       SCM_I_GSC_HAVE_STRUCT_DIRENT64);
 359
 360   pf ("/* Define to 1 if `readdir64_r ()' is available.  */\n");
 361 #ifdef HAVE_READDIR64_R
 362   pf ("#define SCM_HAVE_READDIR64_R 1 /* 0 or 1 */\n");
 363 #else
 364   pf ("#define SCM_HAVE_READDIR64_R 0 /* 0 or 1 */\n");
 365 #endif
 366
 367   /* Arrange so that we have a file offset type that reflects the one
 368      used when compiling Guile, regardless of what the application's
 369      `_FILE_OFFSET_BITS' says.  See
 370      http://lists.gnu.org/archive/html/bug-guile/2009-06/msg00018.html
 371      for the original bug report.
 372
 373      Note that we can't define `scm_t_off' in terms of `off_t' or
 374      `off64_t' because they may or may not be available depending on
 375      how the application that uses Guile is compiled.  */
 376
 377 #if defined GUILE_USE_64_CALLS && defined HAVE_STAT64
 378   pf ("typedef scm_t_int64 scm_t_off;\n");
 379 #elif SIZEOF_OFF_T == SIZEOF_INT
 380   pf ("typedef int scm_t_off;\n");
 381 #else
 382   pf ("typedef long int scm_t_off;\n");
 383 #endif
 384
 385   pf ("/* Define to 1 if the compiler supports the "
 386       "`__thread' storage class.  */\n");
 387   if (SCM_I_GSC_HAVE_THREAD_STORAGE_CLASS)
 388     pf ("#define SCM_HAVE_THREAD_STORAGE_CLASS\n");
 389   else
 390     pf ("/* #undef SCM_HAVE_THREAD_STORAGE_CLASS */\n");
 391
 392 #ifdef USE_DLL_IMPORT
 393   pf ("\n");
 394   pf ("/* Define some additional CPP macros on Win32 platforms. */\n");
 395   pf ("# define __REGEX_IMPORT__ 1\n");
 396   pf ("# define __CRYPT_IMPORT__ 1\n");
 397   pf ("# define __READLINE_IMPORT__ 1\n");
 398   pf ("# define QT_IMPORT 1\n");
 399 #endif
 400
 401   pf ("\n");
 402   pf ("#define SCM_HAVE_ARRAYS 1 /* always true now */\n");
 403
 404   pf ("\n");
 405   pf ("/* Constants from uniconv.h.  */\n");
 406   pf ("#define SCM_ICONVEH_ERROR %d\n", SCM_I_GSC_ICONVEH_ERROR);
 407   pf ("#define SCM_ICONVEH_QUESTION_MARK %d\n",
 408       SCM_I_GSC_ICONVEH_QUESTION_MARK);
 409   pf ("#define SCM_ICONVEH_ESCAPE_SEQUENCE %d\n",
 410       SCM_I_GSC_ICONVEH_ESCAPE_SEQUENCE);
 411
 412   printf ("#endif\n");
 413
 414   return 0;
 415 }