libguile/load.c

   1 /* Copyright (C) 1995,1996,1998,1999,2000,2001, 2004 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/srfi-13.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 SCM_DEFINE (scm_primitive_load, "primitive-load", 1, 0, 0,
  65            (SCM filename),
  66             "Load the file named @var{filename} and evaluate its contents in\n"
  67             "the top-level environment. The load paths are not searched;\n"
  68             "@var{filename} must either be a full pathname or be a pathname\n"
  69             "relative to the current directory.  If the  variable\n"
  70             "@code{%load-hook} is defined, it should be bound to a procedure\n"
  71             "that will be called before any code is loaded.  See the\n"
  72             "documentation for @code{%load-hook} later in this section.")
  73 #define FUNC_NAME s_scm_primitive_load
  74 {
  75   SCM hook = *scm_loc_load_hook;
  76   SCM_VALIDATE_STRING (1, filename);
  77   if (scm_is_true (hook) && scm_is_false (scm_procedure_p (hook)))
  78     SCM_MISC_ERROR ("value of %load-hook is neither a procedure nor #f",
  79                     SCM_EOL);
  80
  81   if (!scm_is_false (hook))
  82     scm_call_1 (hook, filename);
  83
  84   { /* scope */
  85     SCM port = scm_open_file (filename, scm_from_locale_string ("r"));
  86     scm_frame_begin (SCM_F_FRAME_REWINDABLE);
  87     scm_i_frame_current_load_port (port);
  88
  89     while (1)
  90       {
  91         SCM form = scm_read (port);
  92         if (SCM_EOF_OBJECT_P (form))
  93           break;
  94         scm_primitive_eval_x (form);
  95       }
  96
  97     scm_frame_end ();
  98     scm_close_port (port);
  99   }
 100   return SCM_UNSPECIFIED;
 101 }
 102 #undef FUNC_NAME
 103
 104 SCM
 105 scm_c_primitive_load (const char *filename)
 106 {
 107   return scm_primitive_load (scm_from_locale_string (filename));
 108 }
 109
 110 \f
 111 /* Builtin path to scheme library files. */
 112 #ifdef SCM_PKGDATA_DIR
 113 SCM_DEFINE (scm_sys_package_data_dir, "%package-data-dir", 0, 0, 0,
 114             (),
 115             "Return the name of the directory where Scheme packages, modules and\n"
 116             "libraries are kept.  On most Unix systems, this will be\n"
 117             "@samp{/usr/local/share/guile}.")
 118 #define FUNC_NAME s_scm_sys_package_data_dir
 119 {
 120   return scm_from_locale_string (SCM_PKGDATA_DIR);
 121 }
 122 #undef FUNC_NAME
 123 #endif /* SCM_PKGDATA_DIR */
 124
 125 #ifdef SCM_LIBRARY_DIR
 126 SCM_DEFINE (scm_sys_library_dir, "%library-dir", 0,0,0,
 127             (),
 128             "Return the directory where the Guile Scheme library files are installed.\n"
 129             "E.g., may return \"/usr/share/guile/1.3.5\".")
 130 #define FUNC_NAME s_scm_sys_library_dir
 131 {
 132   return scm_from_locale_string (SCM_LIBRARY_DIR);
 133 }
 134 #undef FUNC_NAME
 135 #endif /* SCM_LIBRARY_DIR */
 136
 137 #ifdef SCM_SITE_DIR
 138 SCM_DEFINE (scm_sys_site_dir, "%site-dir", 0,0,0,
 139             (),
 140             "Return the directory where the Guile site files are installed.\n"
 141             "E.g., may return \"/usr/share/guile/site\".")
 142 #define FUNC_NAME s_scm_sys_site_dir
 143 {
 144   return scm_from_locale_string (SCM_SITE_DIR);
 145 }
 146 #undef FUNC_NAME
 147 #endif /* SCM_SITE_DIR */
 148
 149
 150
 151 \f
 152 /* Initializing the load path, and searching it.  */
 153
 154 /* List of names of directories we search for files to load.  */
 155 static SCM *scm_loc_load_path;
 156
 157 /* List of extensions we try adding to the filenames.  */
 158 static SCM *scm_loc_load_extensions;
 159
 160
 161 SCM_DEFINE (scm_parse_path, "parse-path", 1, 1, 0,
 162             (SCM path, SCM tail),
 163             "Parse @var{path}, which is expected to be a colon-separated\n"
 164             "string, into a list and return the resulting list with\n"
 165             "@var{tail} appended. If @var{path} is @code{#f}, @var{tail}\n"
 166             "is returned.")
 167 #define FUNC_NAME s_scm_parse_path
 168 {
 169 #ifdef __MINGW32__
 170   SCM sep = SCM_MAKE_CHAR (';');
 171 #else
 172   SCM sep = SCM_MAKE_CHAR (':');
 173 #endif
 174
 175   if (SCM_UNBNDP (tail))
 176     tail = SCM_EOL;
 177   return (scm_is_false (path)
 178           ? tail
 179           : scm_append_x (scm_list_2 (scm_string_split (path, sep), tail)));
 180 }
 181 #undef FUNC_NAME
 182
 183
 184 /* Initialize the global variable %load-path, given the value of the
 185    SCM_SITE_DIR and SCM_LIBRARY_DIR preprocessor symbols and the
 186    GUILE_LOAD_PATH environment variable.  */
 187 void
 188 scm_init_load_path ()
 189 {
 190   char *env;
 191   SCM path = SCM_EOL;
 192
 193 #ifdef SCM_LIBRARY_DIR
 194   path = scm_list_3 (scm_from_locale_string (SCM_SITE_DIR),
 195                      scm_from_locale_string (SCM_LIBRARY_DIR),
 196                      scm_from_locale_string (SCM_PKGDATA_DIR));
 197 #endif /* SCM_LIBRARY_DIR */
 198
 199   env = getenv ("GUILE_LOAD_PATH");
 200   if (env)
 201     path = scm_parse_path (scm_from_locale_string (env), path);
 202
 203   *scm_loc_load_path = path;
 204 }
 205
 206 SCM scm_listofnullstr;
 207
 208 /* Utility functions for assembling C strings in a buffer.
 209  */
 210
 211 struct stringbuf {
 212   char *buf, *ptr;
 213   size_t buf_len;
 214 };
 215
 216 static void
 217 stringbuf_free (void *data)
 218 {
 219   struct stringbuf *buf = (struct stringbuf *)data;
 220   free (buf->buf);
 221 }
 222
 223 static void
 224 stringbuf_grow (struct stringbuf *buf)
 225 {
 226   size_t ptroff = buf->ptr - buf->buf;
 227   buf->buf_len *= 2;
 228   buf->buf = scm_realloc (buf->buf, buf->buf_len);
 229   buf->ptr = buf->buf + ptroff;
 230 }
 231
 232 static void
 233 stringbuf_cat_locale_string (struct stringbuf *buf, SCM str)
 234 {
 235   size_t max_len = buf->buf_len - (buf->ptr - buf->buf) - 1;
 236   size_t len = scm_to_locale_stringbuf (str, buf->ptr, max_len);
 237   if (len > max_len)
 238     {
 239       /* buffer is too small, double its size and try again.
 240        */
 241       stringbuf_grow (buf);
 242       stringbuf_cat_locale_string (buf, str);
 243     }
 244   else
 245     {
 246       /* string fits, terminate it and check for embedded '\0'.
 247        */
 248       buf->ptr[len] = '\0';
 249       if (strlen (buf->ptr) != len)
 250         scm_misc_error (NULL,
 251                         "string contains #\\nul character: ~S",
 252                         scm_list_1 (str));
 253       buf->ptr += len;
 254     }
 255 }
 256
 257 static void
 258 stringbuf_cat (struct stringbuf *buf, char *str)
 259 {
 260   size_t max_len = buf->buf_len - (buf->ptr - buf->buf) - 1;
 261   size_t len = strlen (str);
 262   if (len > max_len)
 263     {
 264       /* buffer is too small, double its size and try again.
 265        */
 266       stringbuf_grow (buf);
 267       stringbuf_cat (buf, str);
 268     }
 269   else
 270     {
 271       /* string fits, copy it into buffer.
 272        */
 273       strcpy (buf->ptr, str);
 274       buf->ptr += len;
 275     }
 276 }
 277
 278
 279 /* Search PATH for a directory containing a file named FILENAME.
 280    The file must be readable, and not a directory.
 281    If we find one, return its full filename; otherwise, return #f.
 282    If FILENAME is absolute, return it unchanged.
 283    If given, EXTENSIONS is a list of strings; for each directory
 284    in PATH, we search for FILENAME concatenated with each EXTENSION.  */
 285 SCM_DEFINE (scm_search_path, "search-path", 2, 1, 0,
 286            (SCM path, SCM filename, SCM extensions),
 287             "Search @var{path} for a directory containing a file named\n"
 288             "@var{filename}. The file must be readable, and not a directory.\n"
 289             "If we find one, return its full filename; otherwise, return\n"
 290             "@code{#f}.  If @var{filename} is absolute, return it unchanged.\n"
 291             "If given, @var{extensions} is a list of strings; for each\n"
 292             "directory in @var{path}, we search for @var{filename}\n"
 293             "concatenated with each @var{extension}.")
 294 #define FUNC_NAME s_scm_search_path
 295 {
 296   struct stringbuf buf;
 297   char *filename_chars;
 298   size_t filename_len;
 299   SCM result = SCM_BOOL_F;
 300
 301   if (SCM_UNBNDP (extensions))
 302     extensions = SCM_EOL;
 303
 304   scm_frame_begin (0);
 305
 306   filename_chars = scm_to_locale_string (filename);
 307   filename_len = strlen (filename_chars);
 308   scm_frame_free (filename_chars);
 309
 310   /* If FILENAME is absolute, return it unchanged.  */
 311 #ifdef __MINGW32__
 312   if (((filename_len >= 1) &&
 313        (filename_chars[0] == '/' || filename_chars[0] == '\\')) ||
 314       ((filename_len >= 3) && filename_chars[1] == ':' &&
 315        ((filename_chars[0] >= 'a' && filename_chars[0] <= 'z') ||
 316         (filename_chars[0] >= 'A' && filename_chars[0] <= 'Z')) &&
 317        (filename_chars[2] == '/' || filename_chars[2] == '\\')))
 318 #else
 319   if (filename_len >= 1 && filename_chars[0] == '/')
 320 #endif
 321     {
 322       scm_frame_end ();
 323       return filename;
 324     }
 325
 326   /* If FILENAME has an extension, don't try to add EXTENSIONS to it.  */
 327   {
 328     char *endp;
 329
 330     for (endp = filename_chars + filename_len - 1;
 331          endp >= filename_chars;
 332          endp--)
 333       {
 334         if (*endp == '.')
 335           {
 336             /* This filename already has an extension, so cancel the
 337                list of extensions.  */
 338             extensions = SCM_EOL;
 339             break;
 340           }
 341 #ifdef __MINGW32__
 342         else if (*endp == '/' || *endp == '\\')
 343 #else
 344         else if (*endp == '/')
 345 #endif
 346           /* This filename has no extension, so keep the current list
 347              of extensions.  */
 348           break;
 349       }
 350   }
 351
 352   /* This simplifies the loop below a bit.
 353    */
 354   if (scm_is_null (extensions))
 355     extensions = scm_listofnullstr;
 356
 357   buf.buf_len = 512;
 358   buf.buf = scm_malloc (buf.buf_len);
 359   scm_frame_unwind_handler (stringbuf_free, &buf, SCM_F_WIND_EXPLICITLY);
 360
 361   /* Try every path element.
 362    */
 363   for (; scm_is_pair (path); path = SCM_CDR (path))
 364     {
 365       SCM dir = SCM_CAR (path);
 366       SCM exts;
 367       size_t sans_ext_len;
 368
 369       buf.ptr = buf.buf;
 370       stringbuf_cat_locale_string (&buf, dir);
 371
 372       /* Concatenate the path name and the filename. */
 373
 374 #ifdef __MINGW32__
 375       if (buf.ptr > buf.buf && buf.ptr[-1] != '/' && buf.ptr[-1] != '\\')
 376 #else
 377       if (buf.ptr > buf.buf >= 1 && buf.ptr[-1] != '/')
 378 #endif
 379         stringbuf_cat (&buf, "/");
 380
 381       stringbuf_cat (&buf, filename_chars);
 382       sans_ext_len = buf.ptr - buf.buf;
 383
 384       /* Try every extension. */
 385       for (exts = extensions; scm_is_pair (exts); exts = SCM_CDR (exts))
 386         {
 387           SCM ext = SCM_CAR (exts);
 388           struct stat mode;
 389
 390           buf.ptr = buf.buf + sans_ext_len;
 391           stringbuf_cat_locale_string (&buf, ext);
 392
 393           /* If the file exists at all, we should return it.  If the
 394              file is inaccessible, then that's an error.  */
 395
 396           if (stat (buf.buf, &mode) == 0
 397               && ! (mode.st_mode & S_IFDIR))
 398             {
 399               result = scm_from_locale_string (buf.buf);
 400               goto end;
 401             }
 402         }
 403
 404       if (!SCM_NULL_OR_NIL_P (exts))
 405         scm_wrong_type_arg_msg (NULL, 0, extensions, "proper list");
 406     }
 407
 408   if (!SCM_NULL_OR_NIL_P (path))
 409     scm_wrong_type_arg_msg (NULL, 0, path, "proper list");
 410
 411  end:
 412   scm_frame_end ();
 413   return result;
 414 }
 415 #undef FUNC_NAME
 416
 417
 418 /* Search %load-path for a directory containing a file named FILENAME.
 419    The file must be readable, and not a directory.
 420    If we find one, return its full filename; otherwise, return #f.
 421    If FILENAME is absolute, return it unchanged.  */
 422 SCM_DEFINE (scm_sys_search_load_path, "%search-load-path", 1, 0, 0,
 423             (SCM filename),
 424             "Search @var{%load-path} for the file named @var{filename},\n"
 425             "which must be readable by the current user.  If @var{filename}\n"
 426             "is found in the list of paths to search or is an absolute\n"
 427             "pathname, return its full pathname.  Otherwise, return\n"
 428             "@code{#f}.  Filenames may have any of the optional extensions\n"
 429             "in the @code{%load-extensions} list; @code{%search-load-path}\n"
 430             "will try each extension automatically.")
 431 #define FUNC_NAME s_scm_sys_search_load_path
 432 {
 433   SCM path = *scm_loc_load_path;
 434   SCM exts = *scm_loc_load_extensions;
 435   SCM_VALIDATE_STRING (1, filename);
 436
 437   if (scm_ilength (path) < 0)
 438     SCM_MISC_ERROR ("%load-path is not a proper list", SCM_EOL);
 439   if (scm_ilength (exts) < 0)
 440     SCM_MISC_ERROR ("%load-extension list is not a proper list", SCM_EOL);
 441   return scm_search_path (path, filename, exts);
 442 }
 443 #undef FUNC_NAME
 444
 445
 446 SCM_DEFINE (scm_primitive_load_path, "primitive-load-path", 1, 0, 0,
 447             (SCM filename),
 448             "Search @var{%load-path} for the file named @var{filename} and\n"
 449             "load it into the top-level environment.  If @var{filename} is a\n"
 450             "relative pathname and is not found in the list of search paths,\n"
 451             "an error is signalled.")
 452 #define FUNC_NAME s_scm_primitive_load_path
 453 {
 454   SCM full_filename;
 455
 456   full_filename = scm_sys_search_load_path (filename);
 457
 458   if (scm_is_false (full_filename))
 459     SCM_MISC_ERROR ("Unable to find file ~S in load path",
 460                     scm_list_1 (filename));
 461
 462   return scm_primitive_load (full_filename);
 463 }
 464 #undef FUNC_NAME
 465
 466 SCM
 467 scm_c_primitive_load_path (const char *filename)
 468 {
 469   return scm_primitive_load_path (scm_from_locale_string (filename));
 470 }
 471
 472 \f
 473 /* Information about the build environment.  */
 474
 475 /* Initialize the scheme variable %guile-build-info, based on data
 476    provided by the Makefile, via libpath.h.  */
 477 static void
 478 init_build_info ()
 479 {
 480   static struct { char *name; char *value; } info[] = SCM_BUILD_INFO;
 481   SCM *loc = SCM_VARIABLE_LOC (scm_c_define ("%guile-build-info", SCM_EOL));
 482   unsigned long i;
 483
 484   for (i = 0; i < (sizeof (info) / sizeof (info[0])); i++)
 485     {
 486       SCM key = scm_from_locale_symbol (info[i].name);
 487       SCM val = scm_from_locale_string (info[i].value);
 488       *loc = scm_acons (key, val, *loc);
 489     }
 490 }
 491
 492 \f
 493 void
 494 scm_init_load ()
 495 {
 496   scm_listofnullstr = scm_permanent_object (scm_list_1 (scm_nullstr));
 497   scm_loc_load_path = SCM_VARIABLE_LOC (scm_c_define ("%load-path", SCM_EOL));
 498   scm_loc_load_extensions
 499     = SCM_VARIABLE_LOC (scm_c_define ("%load-extensions",
 500                                       scm_list_2 (scm_from_locale_string (".scm"),
 501                                                   scm_nullstr)));
 502   scm_loc_load_hook = SCM_VARIABLE_LOC (scm_c_define ("%load-hook", SCM_BOOL_F));
 503
 504   init_build_info ();
 505
 506 #include "libguile/load.x"
 507 }
 508
 509 /*
 510   Local Variables:
 511   c-file-style: "gnu"
 512   End:
 513 */