libguile/load.c

   1 /* Copyright (C) 1995,1996,1998,1999,2000,2001 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
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  16  */
  17
  18
  19 \f
  20
  21 #if HAVE_CONFIG_H
  22 #  include <config.h>
  23 #endif
  24
  25 #include <string.h>
  26 #include <stdio.h>
  27
  28 #include "libguile/_scm.h"
  29 #include "libguile/libpath.h"
  30 #include "libguile/fports.h"
  31 #include "libguile/read.h"
  32 #include "libguile/eval.h"
  33 #include "libguile/throw.h"
  34 #include "libguile/alist.h"
  35 #include "libguile/dynwind.h"
  36 #include "libguile/root.h"
  37 #include "libguile/strings.h"
  38 #include "libguile/modules.h"
  39 #include "libguile/lang.h"
  40 #include "libguile/chars.h"
  41 #include "libguile/strop.h"
  42
  43 #include "libguile/validate.h"
  44 #include "libguile/load.h"
  45
  46 #include <sys/types.h>
  47 #include <sys/stat.h>
  48
  49 #ifdef HAVE_UNISTD_H
  50 #include <unistd.h>
  51 #endif /* HAVE_UNISTD_H */
  52
  53 #ifndef R_OK
  54 #define R_OK 4
  55 #endif
  56
  57 \f
  58 /* Loading a file, given an absolute filename.  */
  59
  60 /* Hook to run when we load a file, perhaps to announce the fact somewhere.
  61    Applied to the full name of the file.  */
  62 static SCM *scm_loc_load_hook;
  63
  64 static void
  65 swap_port (void *data)
  66 {
  67   SCM *save_port = data, tmp = scm_cur_loadp;
  68   scm_cur_loadp = *save_port;
  69   *save_port = tmp;
  70 }
  71
  72 static SCM
  73 load (void *data)
  74 {
  75   SCM port = SCM_PACK (data);
  76   while (1)
  77     {
  78       SCM form = scm_read (port);
  79       if (SCM_EOF_OBJECT_P (form))
  80         break;
  81       scm_primitive_eval_x (form);
  82     }
  83   return SCM_UNSPECIFIED;
  84 }
  85
  86 SCM_DEFINE (scm_primitive_load, "primitive-load", 1, 0, 0,
  87            (SCM filename),
  88             "Load the file named @var{filename} and evaluate its contents in\n"
  89             "the top-level environment. The load paths are not searched;\n"
  90             "@var{filename} must either be a full pathname or be a pathname\n"
  91             "relative to the current directory.  If the  variable\n"
  92             "@code{%load-hook} is defined, it should be bound to a procedure\n"
  93             "that will be called before any code is loaded.  See the\n"
  94             "documentation for @code{%load-hook} later in this section.")
  95 #define FUNC_NAME s_scm_primitive_load
  96 {
  97   SCM hook = *scm_loc_load_hook;
  98   SCM_VALIDATE_STRING (1, filename);
  99   if (scm_is_true (hook) && scm_is_false (scm_procedure_p (hook)))
 100     SCM_MISC_ERROR ("value of %load-hook is neither a procedure nor #f",
 101                     SCM_EOL);
 102
 103   if (!scm_is_false (hook))
 104     scm_call_1 (hook, filename);
 105
 106   { /* scope */
 107     SCM port, save_port;
 108     port = scm_open_file (filename, scm_mem2string ("r", sizeof (char)));
 109     save_port = port;
 110     scm_internal_dynamic_wind (swap_port,
 111                                load,
 112                                swap_port,
 113                                (void *) SCM_UNPACK (port),
 114                                &save_port);
 115     scm_close_port (port);
 116   }
 117   return SCM_UNSPECIFIED;
 118 }
 119 #undef FUNC_NAME
 120
 121 SCM
 122 scm_c_primitive_load (const char *filename)
 123 {
 124   return scm_primitive_load (scm_makfrom0str (filename));
 125 }
 126
 127 \f
 128 /* Builtin path to scheme library files. */
 129 #ifdef SCM_PKGDATA_DIR
 130 SCM_DEFINE (scm_sys_package_data_dir, "%package-data-dir", 0, 0, 0,
 131             (),
 132             "Return the name of the directory where Scheme packages, modules and\n"
 133             "libraries are kept.  On most Unix systems, this will be\n"
 134             "@samp{/usr/local/share/guile}.")
 135 #define FUNC_NAME s_scm_sys_package_data_dir
 136 {
 137   return scm_makfrom0str (SCM_PKGDATA_DIR);
 138 }
 139 #undef FUNC_NAME
 140 #endif /* SCM_PKGDATA_DIR */
 141
 142 #ifdef SCM_LIBRARY_DIR
 143 SCM_DEFINE (scm_sys_library_dir, "%library-dir", 0,0,0,
 144             (),
 145             "Return the directory where the Guile Scheme library files are installed.\n"
 146             "E.g., may return \"/usr/share/guile/1.3.5\".")
 147 #define FUNC_NAME s_scm_sys_library_dir
 148 {
 149   return scm_makfrom0str(SCM_LIBRARY_DIR);
 150 }
 151 #undef FUNC_NAME
 152 #endif /* SCM_LIBRARY_DIR */
 153
 154 #ifdef SCM_SITE_DIR
 155 SCM_DEFINE (scm_sys_site_dir, "%site-dir", 0,0,0,
 156             (),
 157             "Return the directory where the Guile site files are installed.\n"
 158             "E.g., may return \"/usr/share/guile/site\".")
 159 #define FUNC_NAME s_scm_sys_site_dir
 160 {
 161   return scm_makfrom0str(SCM_SITE_DIR);
 162 }
 163 #undef FUNC_NAME
 164 #endif /* SCM_SITE_DIR */
 165
 166
 167
 168 \f
 169 /* Initializing the load path, and searching it.  */
 170
 171 /* List of names of directories we search for files to load.  */
 172 static SCM *scm_loc_load_path;
 173
 174 /* List of extensions we try adding to the filenames.  */
 175 static SCM *scm_loc_load_extensions;
 176
 177
 178 SCM_DEFINE (scm_parse_path, "parse-path", 1, 1, 0,
 179             (SCM path, SCM tail),
 180             "Parse @var{path}, which is expected to be a colon-separated\n"
 181             "string, into a list and return the resulting list with\n"
 182             "@var{tail} appended. If @var{path} is @code{#f}, @var{tail}\n"
 183             "is returned.")
 184 #define FUNC_NAME s_scm_parse_path
 185 {
 186 #ifdef __MINGW32__
 187   SCM sep = SCM_MAKE_CHAR (';');
 188 #else
 189   SCM sep = SCM_MAKE_CHAR (':');
 190 #endif
 191
 192   if (SCM_UNBNDP (tail))
 193     tail = SCM_EOL;
 194   return (scm_is_false (path)
 195           ? tail
 196           : scm_append_x (scm_list_2 (scm_string_split (path, sep), tail)));
 197 }
 198 #undef FUNC_NAME
 199
 200
 201 /* Initialize the global variable %load-path, given the value of the
 202    SCM_SITE_DIR and SCM_LIBRARY_DIR preprocessor symbols and the
 203    GUILE_LOAD_PATH environment variable.  */
 204 void
 205 scm_init_load_path ()
 206 {
 207   SCM path = SCM_EOL;
 208
 209 #ifdef SCM_LIBRARY_DIR
 210   path = scm_list_3 (scm_makfrom0str (SCM_SITE_DIR),
 211                      scm_makfrom0str (SCM_LIBRARY_DIR),
 212                      scm_makfrom0str (SCM_PKGDATA_DIR));
 213 #endif /* SCM_LIBRARY_DIR */
 214
 215   path = scm_parse_path (scm_from_locale_string (getenv ("GUILE_LOAD_PATH")),
 216                          path);
 217
 218   *scm_loc_load_path = path;
 219 }
 220
 221 SCM scm_listofnullstr;
 222
 223 /* Utility functions for assembling C strings in a buffer.
 224  */
 225
 226 struct stringbuf {
 227   char *buf, *ptr;
 228   size_t buf_len;
 229 };
 230
 231 static void
 232 stringbuf_free (void *data)
 233 {
 234   struct stringbuf *buf = (struct stringbuf *)data;
 235   free (buf->buf);
 236 }
 237
 238 static void
 239 stringbuf_grow (struct stringbuf *buf)
 240 {
 241   size_t ptroff = buf->ptr - buf->buf;
 242   buf->buf_len *= 2;
 243   buf->buf = scm_realloc (buf->buf, buf->buf_len);
 244   buf->ptr = buf->buf + ptroff;
 245 }
 246
 247 static void
 248 stringbuf_cat_locale_string (struct stringbuf *buf, SCM str)
 249 {
 250   size_t max_len = buf->buf_len - (buf->ptr - buf->buf) - 1;
 251   size_t len = scm_to_locale_stringbuf (str, buf->ptr, max_len);
 252   if (len > max_len)
 253     {
 254       /* buffer is too small, double its size and try again.
 255        */
 256       stringbuf_grow (buf);
 257       stringbuf_cat_locale_string (buf, str);
 258     }
 259   else
 260     {
 261       /* string fits, terminate it and check for embedded '\0'.
 262        */
 263       buf->ptr[len] = '\0';
 264       if (strlen (buf->ptr) != len)
 265         scm_misc_error (NULL,
 266                         "string contains #\\nul character: ~S",
 267                         scm_list_1 (str));
 268       buf->ptr += len;
 269     }
 270 }
 271
 272 static void
 273 stringbuf_cat (struct stringbuf *buf, char *str)
 274 {
 275   size_t max_len = buf->buf_len - (buf->ptr - buf->buf) - 1;
 276   size_t len = strlen (str);
 277   if (len > max_len)
 278     {
 279       /* buffer is too small, double its size and try again.
 280        */
 281       stringbuf_grow (buf);
 282       stringbuf_cat (buf, str);
 283     }
 284   else
 285     {
 286       /* string fits, copy it into buffer.
 287        */
 288       strcpy (buf->ptr, str);
 289       buf->ptr += len;
 290     }
 291 }
 292
 293
 294 /* Search PATH for a directory containing a file named FILENAME.
 295    The file must be readable, and not a directory.
 296    If we find one, return its full filename; otherwise, return #f.
 297    If FILENAME is absolute, return it unchanged.
 298    If given, EXTENSIONS is a list of strings; for each directory
 299    in PATH, we search for FILENAME concatenated with each EXTENSION.  */
 300 SCM_DEFINE (scm_search_path, "search-path", 2, 1, 0,
 301            (SCM path, SCM filename, SCM extensions),
 302             "Search @var{path} for a directory containing a file named\n"
 303             "@var{filename}. The file must be readable, and not a directory.\n"
 304             "If we find one, return its full filename; otherwise, return\n"
 305             "@code{#f}.  If @var{filename} is absolute, return it unchanged.\n"
 306             "If given, @var{extensions} is a list of strings; for each\n"
 307             "directory in @var{path}, we search for @var{filename}\n"
 308             "concatenated with each @var{extension}.")
 309 #define FUNC_NAME s_scm_search_path
 310 {
 311   struct stringbuf buf;
 312   char *filename_chars;
 313   size_t filename_len;
 314   SCM result = SCM_BOOL_F;
 315
 316   if (SCM_UNBNDP (extensions))
 317     extensions = SCM_EOL;
 318
 319   scm_frame_begin (0);
 320
 321   filename_chars = scm_to_locale_string (filename);
 322   filename_len = strlen (filename_chars);
 323   scm_frame_free (filename_chars);
 324
 325   /* If FILENAME is absolute, return it unchanged.  */
 326 #ifdef __MINGW32__
 327   if (((filename_len >= 1) &&
 328        (filename_chars[0] == '/' || filename_chars[0] == '\\')) ||
 329       ((filename_len >= 3) && filename_chars[1] == ':' &&
 330        ((filename_chars[0] >= 'a' && filename_chars[0] <= 'z') ||
 331         (filename_chars[0] >= 'A' && filename_chars[0] <= 'Z')) &&
 332        (filename_chars[2] == '/' || filename_chars[2] == '\\')))
 333 #else
 334   if (filename_len >= 1 && filename_chars[0] == '/')
 335 #endif
 336     {
 337       scm_frame_end ();
 338       return filename;
 339     }
 340
 341   /* If FILENAME has an extension, don't try to add EXTENSIONS to it.  */
 342   {
 343     char *endp;
 344
 345     for (endp = filename_chars + filename_len - 1;
 346          endp >= filename_chars;
 347          endp--)
 348       {
 349         if (*endp == '.')
 350           {
 351             /* This filename already has an extension, so cancel the
 352                list of extensions.  */
 353             extensions = SCM_EOL;
 354             break;
 355           }
 356 #ifdef __MINGW32__
 357         else if (*endp == '/' || *endp == '\\')
 358 #else
 359         else if (*endp == '/')
 360 #endif
 361           /* This filename has no extension, so keep the current list
 362              of extensions.  */
 363           break;
 364       }
 365   }
 366
 367   /* This simplifies the loop below a bit.
 368    */
 369   if (SCM_NULLP (extensions))
 370     extensions = scm_listofnullstr;
 371
 372   buf.buf_len = 512;
 373   buf.buf = scm_malloc (buf.buf_len);
 374   scm_frame_unwind_handler (stringbuf_free, &buf, SCM_F_WIND_EXPLICITLY);
 375
 376   /* Try every path element.
 377    */
 378   for (; SCM_CONSP (path); path = SCM_CDR (path))
 379     {
 380       SCM dir = SCM_CAR (path);
 381       SCM exts;
 382       size_t sans_ext_len;
 383
 384       buf.ptr = buf.buf;
 385       stringbuf_cat_locale_string (&buf, dir);
 386
 387       /* Concatenate the path name and the filename. */
 388
 389 #ifdef __MINGW32__
 390       if (buf.ptr > buf.buf && buf.ptr[-1] != '/' && buf.ptr[-1] != '\\')
 391 #else
 392       if (buf.ptr > buf.buf >= 1 && buf.ptr[-1] != '/')
 393 #endif
 394         stringbuf_cat (&buf, "/");
 395
 396       stringbuf_cat (&buf, filename_chars);
 397       sans_ext_len = buf.ptr - buf.buf;
 398
 399       /* Try every extension. */
 400       for (exts = extensions; SCM_CONSP (exts); exts = SCM_CDR (exts))
 401         {
 402           SCM ext = SCM_CAR (exts);
 403           struct stat mode;
 404
 405           buf.ptr = buf.buf + sans_ext_len;
 406           stringbuf_cat_locale_string (&buf, ext);
 407
 408           /* If the file exists at all, we should return it.  If the
 409              file is inaccessible, then that's an error.  */
 410
 411           if (stat (buf.buf, &mode) == 0
 412               && ! (mode.st_mode & S_IFDIR))
 413             {
 414               result = scm_from_locale_string (buf.buf);
 415               goto end;
 416             }
 417         }
 418
 419       if (!SCM_NULL_OR_NIL_P (exts))
 420         scm_wrong_type_arg_msg (NULL, 0, extensions, "proper list");
 421     }
 422
 423   if (!SCM_NULL_OR_NIL_P (path))
 424     scm_wrong_type_arg_msg (NULL, 0, path, "proper list");
 425
 426  end:
 427   scm_frame_end ();
 428   return result;
 429 }
 430 #undef FUNC_NAME
 431
 432
 433 /* Search %load-path for a directory containing a file named FILENAME.
 434    The file must be readable, and not a directory.
 435    If we find one, return its full filename; otherwise, return #f.
 436    If FILENAME is absolute, return it unchanged.  */
 437 SCM_DEFINE (scm_sys_search_load_path, "%search-load-path", 1, 0, 0,
 438             (SCM filename),
 439             "Search @var{%load-path} for the file named @var{filename},\n"
 440             "which must be readable by the current user.  If @var{filename}\n"
 441             "is found in the list of paths to search or is an absolute\n"
 442             "pathname, return its full pathname.  Otherwise, return\n"
 443             "@code{#f}.  Filenames may have any of the optional extensions\n"
 444             "in the @code{%load-extensions} list; @code{%search-load-path}\n"
 445             "will try each extension automatically.")
 446 #define FUNC_NAME s_scm_sys_search_load_path
 447 {
 448   SCM path = *scm_loc_load_path;
 449   SCM exts = *scm_loc_load_extensions;
 450   SCM_VALIDATE_STRING (1, filename);
 451
 452   if (scm_ilength (path) < 0)
 453     SCM_MISC_ERROR ("%load-path is not a proper list", SCM_EOL);
 454   if (scm_ilength (exts) < 0)
 455     SCM_MISC_ERROR ("%load-extension list is not a proper list", SCM_EOL);
 456   return scm_search_path (path, filename, exts);
 457 }
 458 #undef FUNC_NAME
 459
 460
 461 SCM_DEFINE (scm_primitive_load_path, "primitive-load-path", 1, 0, 0,
 462             (SCM filename),
 463             "Search @var{%load-path} for the file named @var{filename} and\n"
 464             "load it into the top-level environment.  If @var{filename} is a\n"
 465             "relative pathname and is not found in the list of search paths,\n"
 466             "an error is signalled.")
 467 #define FUNC_NAME s_scm_primitive_load_path
 468 {
 469   SCM full_filename;
 470
 471   SCM_VALIDATE_STRING (1, filename);
 472
 473   full_filename = scm_sys_search_load_path (filename);
 474
 475   if (scm_is_false (full_filename))
 476     {
 477       int absolute = (SCM_STRING_LENGTH (filename) >= 1
 478 #ifdef __MINGW32__
 479                       && (SCM_STRING_CHARS (filename)[0] == '/' ||
 480                           SCM_STRING_CHARS (filename)[0] == '\\'));
 481 #else
 482                       && SCM_STRING_CHARS (filename)[0] == '/');
 483 #endif
 484       SCM_MISC_ERROR ((absolute
 485                        ? "Unable to load file ~S"
 486                        : "Unable to find file ~S in load path"),
 487                       scm_list_1 (filename));
 488     }
 489
 490   return scm_primitive_load (full_filename);
 491 }
 492 #undef FUNC_NAME
 493
 494 SCM
 495 scm_c_primitive_load_path (const char *filename)
 496 {
 497   return scm_primitive_load_path (scm_makfrom0str (filename));
 498 }
 499
 500 \f
 501 /* Information about the build environment.  */
 502
 503 /* Initialize the scheme variable %guile-build-info, based on data
 504    provided by the Makefile, via libpath.h.  */
 505 static void
 506 init_build_info ()
 507 {
 508   static struct { char *name; char *value; } info[] = SCM_BUILD_INFO;
 509   SCM *loc = SCM_VARIABLE_LOC (scm_c_define ("%guile-build-info", SCM_EOL));
 510   unsigned long i;
 511
 512   for (i = 0; i < (sizeof (info) / sizeof (info[0])); i++)
 513     *loc = scm_acons (scm_str2symbol (info[i].name),
 514                       scm_makfrom0str (info[i].value),
 515                       *loc);
 516 }
 517
 518
 519 \f
 520 void
 521 scm_init_load ()
 522 {
 523   scm_listofnullstr = scm_permanent_object (scm_list_1 (scm_nullstr));
 524   scm_loc_load_path = SCM_VARIABLE_LOC (scm_c_define ("%load-path", SCM_EOL));
 525   scm_loc_load_extensions
 526     = SCM_VARIABLE_LOC (scm_c_define ("%load-extensions",
 527                                     scm_list_2 (scm_makfrom0str (".scm"),
 528                                                 scm_nullstr)));
 529   scm_loc_load_hook = SCM_VARIABLE_LOC (scm_c_define ("%load-hook", SCM_BOOL_F));
 530
 531   init_build_info ();
 532
 533 #include "libguile/load.x"
 534 }
 535
 536 /*
 537   Local Variables:
 538   c-file-style: "gnu"
 539   End:
 540 */