X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/b9d5d6546077696ddde32b3ca7375b4a1c60fa9d..ca8cd13072bfab50580a254d42598aac35f8d9cc:/libguile/load.c

diff --git a/libguile/load.c b/libguile/load.c
index a4527afdf..42c0bea7c 100644
--- a/libguile/load.c
+++ b/libguile/load.c
@@ -1,4 +1,4 @@
-/*	Copyright (C) 1995,1996 Free Software Foundation, Inc.
+/*	Copyright (C) 1995,1996,1998,1999 Free Software Foundation, Inc.
  * 
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -12,7 +12,8 @@
  * 
  * You should have received a copy of the GNU General Public License
  * along with this software; see the file COPYING.  If not, write to
- * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
  *
  * As a special exception, the Free Software Foundation gives permission
  * for additional uses of the text contained in its release of GUILE.
@@ -36,8 +37,11 @@
  *
  * If you write modifications of your own for GUILE, it is your choice
  * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice.  
- */
+ * If you do not wish that, delete this exception notice.  */
+
+/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
+   gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
+
 
 
 #include <stdio.h>
@@ -46,7 +50,11 @@
 #include "fports.h"
 #include "read.h"
 #include "eval.h"
+#include "throw.h"
+#include "alist.h"
+#include "dynwind.h"
 
+#include "scm_validate.h"
 #include "load.h"
 
 #include <sys/types.h>
@@ -63,165 +71,441 @@
 
 /* Loading a file, given an absolute filename.  */
 
-SCM_PROC(s_sys_try_load, "primitive-load", 1, 2, 0, scm_primitive_load);
-SCM 
-scm_primitive_load (filename, case_insensitive_p, sharp)
-     SCM filename;
-     SCM case_insensitive_p;
-     SCM sharp;
+/* Hook to run when we load a file, perhaps to announce the fact somewhere.
+   Applied to the full name of the file.  */
+static SCM *scm_loc_load_hook;
+
+static void
+swap_port (void *data)
 {
-  SCM_ASSERT (SCM_NIMP (filename) && SCM_ROSTRINGP (filename), filename,
-	      SCM_ARG1, s_sys_try_load);
-  {
-    SCM form, port;
+  SCM *save_port = data, tmp = scm_cur_loadp;
+  scm_cur_loadp = *save_port;
+  *save_port = tmp;
+}
+
+static SCM
+load (void *data)
+{
+  SCM port = (SCM) data, form;
+  while (1)
+    {
+      form = scm_read (port);
+      if (SCM_EOF_OBJECT_P (form))
+	break;
+      scm_eval_x (form);
+    }
+  return SCM_UNSPECIFIED;
+}
+
+SCM_DEFINE(scm_primitive_load, "primitive-load", 1, 0, 0, 
+           (SCM filename),
+"Load @var{file} and evaluate its contents in the top-level environment.
+The load paths are not searched; @var{file} must either be a full
+pathname or be a pathname relative to the current directory.  If the
+variable @code{%load-hook} is defined, it should be bound to a procedure
+that will be called before any code is loaded.  See documentation for
+@code{%load-hook} later in this section.")
+#define FUNC_NAME s_scm_primitive_load
+{
+  SCM hook = *scm_loc_load_hook;
+  SCM_VALIDATE_ROSTRING(1,filename);
+  SCM_ASSERT (hook == SCM_BOOL_F
+	      || (scm_procedure_p (hook) == SCM_BOOL_T),
+	      hook, "value of %load-hook is neither a procedure nor #f",
+	      FUNC_NAME);
+
+  if (hook != SCM_BOOL_F)
+    scm_apply (hook, scm_listify (filename, SCM_UNDEFINED), SCM_EOL);
+
+  { /* scope */
+    SCM port, save_port;
     port = scm_open_file (filename,
 			  scm_makfromstr ("r", (scm_sizet) sizeof (char), 0));
-    while (1)
-      {
-	form = scm_read (port, case_insensitive_p, sharp);
-	if (SCM_EOF_VAL == form)
-	  break;
-	scm_eval_x (form);
-      }
+    save_port = port;
+    scm_internal_dynamic_wind (swap_port,
+			       load,
+			       swap_port,
+			       (void *) port,
+			       &save_port);
     scm_close_port (port);
   }
   return SCM_UNSPECIFIED;
 }
+#undef FUNC_NAME
+
+
+/* Builtin path to scheme library files. */
+#ifdef SCM_PKGDATA_DIR
+SCM_DEFINE (scm_sys_package_data_dir, "%package-data-dir", 0, 0, 0, 
+            (),
+"Return the name of the directory where Scheme packages, modules and
+libraries are kept.  On most Unix systems, this will be
+@samp{/usr/local/share/guile}.")
+#define FUNC_NAME s_scm_sys_package_data_dir
+{
+  return scm_makfrom0str (SCM_PKGDATA_DIR);
+}
+#undef FUNC_NAME
+#endif /* SCM_PKGDATA_DIR */
+
+#ifdef SCM_LIBRARY_DIR
+SCM_DEFINE (scm_sys_library_dir, "%library-dir", 0,0,0,
+            (),
+"Return the directory where the Guile Scheme library files are installed.
+E.g., may return \"/usr/share/guile/1.3.5\".")
+#define FUNC_NAME s_scm_sys_library_dir
+{
+  return scm_makfrom0str(SCM_LIBRARY_DIR);
+}
+#undef FUNC_NAME
+#endif /* SCM_LIBRARY_DIR */
+
+#ifdef SCM_SITE_DIR
+SCM_DEFINE (scm_sys_site_dir, "%site-dir", 0,0,0,
+            (),
+"Return the directory where the Guile site files are installed.
+E.g., may return \"/usr/share/guile/site\".")
+#define FUNC_NAME s_scm_sys_site_dir
+{
+  return scm_makfrom0str(SCM_SITE_DIR);
+}
+#undef FUNC_NAME
+#endif /* SCM_SITE_DIR */
+
+
 
 
 /* Initializing the load path, and searching it.  */
 
+/* List of names of directories we search for files to load.  */
 static SCM *scm_loc_load_path;
 
+/* List of extensions we try adding to the filenames.  */
+static SCM *scm_loc_load_extensions;
+
+
+/* Parse the null-terminated string PATH as if it were a standard path
+   environment variable (i.e. a colon-separated list of strings), and
+   prepend the elements to TAIL.  */
+SCM
+scm_internal_parse_path (char *path, SCM tail)
+{
+  if (path && path[0] != '\0')
+    {
+      char *scan, *elt_end;
+
+      /* Scan backwards from the end of the string, to help
+	 construct the list in the right order.  */
+      scan = elt_end = path + strlen (path);
+      do {
+	/* Scan back to the beginning of the current element.  */
+	do scan--;
+	while (scan >= path && *scan != ':');
+	tail = scm_cons (scm_makfromstr (scan + 1, elt_end - (scan + 1), 0),
+			 tail);
+	elt_end = scan;
+      } while (scan >= path);
+    }
+
+  return tail;
+}
+
+
+SCM_DEFINE (scm_parse_path, "parse-path", 1, 1, 0, 
+            (SCM path, SCM tail),
+"")
+#define FUNC_NAME s_scm_parse_path
+{
+  SCM_ASSERT (SCM_FALSEP (path) || (SCM_ROSTRINGP (path)),
+	      path,
+	      SCM_ARG1, FUNC_NAME);
+  if (SCM_UNBNDP (tail))
+    tail = SCM_EOL;
+  return (SCM_FALSEP (path)
+	  ? tail
+	  : scm_internal_parse_path (SCM_ROCHARS (path), tail));
+}
+#undef FUNC_NAME
+
+
 /* Initialize the global variable %load-path, given the value of the
-   LIBRARY_PATH preprocessor symbol and the SCHEME_LOAD_PATH
-   environment variable.  */
+   SCM_SITE_DIR and SCM_LIBRARY_DIR preprocessor symbols and the
+   GUILE_LOAD_PATH environment variable.  */
 void
 scm_init_load_path ()
 {
   SCM path = SCM_EOL;
 
-#ifdef LIBRARY_PATH
-  path = scm_cons (scm_makfrom0str (LIBRARY_PATH), path);
-#endif /* LIBRARY_PATH */
-  
-  {
-    char *path_string = getenv ("SCHEME_LOAD_PATH");
+#ifdef SCM_LIBRARY_DIR
+  path = scm_listify (scm_makfrom0str (SCM_SITE_DIR),
+		      scm_makfrom0str (SCM_LIBRARY_DIR),
+		      scm_makfrom0str (SCM_PKGDATA_DIR),
+		      SCM_UNDEFINED);
+#endif /* SCM_LIBRARY_DIR */
 
-    if (path_string && path_string[0] != '\0')
-      {
-	char *scan, *elt_end;
-
-	/* Scan backwards from the end of the string, to help
-           construct the list in the right order.  */
-	scan = elt_end = path_string + strlen (path_string);
-	do {
-	  /* Scan back to the beginning of the current element.  */
-	  do scan--;
-	  while (scan >= path_string && *scan != ':');
-	  path = scm_cons (scm_makfromstr (scan + 1, elt_end - (scan + 1), 0),
-			   path);
-	  elt_end = scan;
-	} while (scan >= path_string);
-      }
-  }
+  path = scm_internal_parse_path (getenv ("GUILE_LOAD_PATH"), path);
 
   *scm_loc_load_path = path;
 }
 
+SCM scm_listofnullstr;
 
-/* Search %load-path for a directory containing a file named FILENAME.
+/* Search PATH for a directory containing a file named FILENAME.
    The file must be readable, and not a directory.
-   If we find one, return its full filename; otherwise, return #f.  */
-SCM_PROC(s_sys_search_load_path, "%search-load-path", 1, 0, 0, scm_sys_search_load_path);
-SCM 
-scm_sys_search_load_path (filename)
-     SCM filename;
+   If we find one, return its full filename; otherwise, return #f.
+   If FILENAME is absolute, return it unchanged.
+   If given, EXTENSIONS is a list of strings; for each directory 
+   in PATH, we search for FILENAME concatenated with each EXTENSION.  */
+SCM_DEFINE(scm_search_path, "search-path", 2, 1, 0,
+           (SCM path, SCM filename, SCM extensions),
+"")
+#define FUNC_NAME s_scm_search_path
 {
-  SCM path = *scm_loc_load_path;
-  char *buf;
-  int buf_size;
+  char *filename_chars;
   int filename_len;
+  size_t max_path_len;		/* maximum length of any PATH element */
+  size_t max_ext_len;		/* maximum length of any EXTENSIONS element */
+
+  SCM_VALIDATE_LIST(1,path);
+  SCM_VALIDATE_ROSTRING(2,filename);
+  if (SCM_UNBNDP (extensions))
+    extensions = SCM_EOL;
+  else
+    SCM_VALIDATE_LIST(3,extensions);
 
-  SCM_ASSERT (SCM_NIMP (filename) && SCM_ROSTRINGP (filename), filename,
-	      SCM_ARG1, s_sys_search_load_path);
+  filename_chars = SCM_ROCHARS (filename);
   filename_len = SCM_ROLENGTH (filename);
 
+  /* If FILENAME is absolute, return it unchanged.  */
+  if (filename_len >= 1 && filename_chars[0] == '/')
+    return filename;
+
+  /* Find the length of the longest element of path.  */
+  {
+    SCM walk;
+
+    max_path_len = 0;
+    for (walk = path; SCM_NIMP (walk); walk = SCM_CDR (walk))
+      {
+	SCM elt = SCM_CAR (walk);
+	SCM_ASSERT (SCM_ROSTRINGP (elt), elt,
+		    "path is not a list of strings",
+		    FUNC_NAME);
+	if (SCM_ROLENGTH (elt) > max_path_len)
+	  max_path_len = SCM_ROLENGTH (elt);
+      }
+  }
+
+  /* If FILENAME has an extension, don't try to add EXTENSIONS to it.  */
+  {
+    char *endp;
+
+    for (endp = filename_chars + filename_len - 1;
+	 endp >= filename_chars;
+	 endp--)
+      {
+	if (*endp == '.')
+	  {
+	    /* This filename already has an extension, so cancel the
+               list of extensions.  */
+	    extensions = SCM_EOL;
+	    break;
+	  }
+	else if (*endp == '/')
+	  /* This filename has no extension, so keep the current list
+             of extensions.  */
+	  break;
+      }
+  }
+
+  /* Find the length of the longest element of the load extensions
+     list.  */
+  { /* scope */
+    SCM walk;
+
+    max_ext_len = 0;
+    for (walk = extensions; SCM_NIMP (walk); walk = SCM_CDR (walk))
+      {
+	SCM elt = SCM_CAR (walk);
+	SCM_ASSERT (SCM_ROSTRINGP (elt), elt,
+		    "extension list is not a list of strings",
+		    FUNC_NAME);
+	if (SCM_ROLENGTH (elt) > max_ext_len)
+	  max_ext_len = SCM_ROLENGTH (elt);
+      }
+  }
+
   SCM_DEFER_INTS;
 
-  buf_size = 80;
-  buf = scm_must_malloc (buf_size, s_sys_search_load_path);
+  { /* scope */
+    SCM result = SCM_BOOL_F;
+    int buf_size = max_path_len + 1 + filename_len + max_ext_len + 1;
+    char *buf = SCM_MUST_MALLOC (buf_size);
 
-  while (SCM_NIMP (path) && SCM_CONSP (path))
-    {
-      SCM elt = SCM_CAR (path);
-      if (SCM_NIMP (elt) && SCM_ROSTRINGP (elt))
-	{
-	  int len = SCM_ROLENGTH (elt) + 1 + filename_len;
-
-	  if (len + 1 > buf_size)
-	    {
-	      int old_size = buf_size;
-	      buf_size = len + 50;
-	      buf = scm_must_realloc (buf, old_size, buf_size,
-				      s_sys_search_load_path);
-	    }
-
-	  memcpy (buf, SCM_ROCHARS (elt), SCM_ROLENGTH (elt));
-	  buf[SCM_ROLENGTH (elt)] = '/';
-	  memcpy (buf + SCM_ROLENGTH (elt) + 1,
-		  SCM_ROCHARS (filename), filename_len);
-	  buf[len] = '\0';
+    /* This simplifies the loop below a bit.  */
+    if (SCM_NULLP (extensions))
+      extensions = scm_listofnullstr;
+
+    /* Try every path element.  At this point, we know the path is a
+       proper list of strings.  */
+    for (; SCM_NIMP (path); path = SCM_CDR (path))
+      {
+	int len;
+	SCM dir = SCM_CAR (path);
+	SCM exts;
 
+	/* Concatenate the path name and the filename. */
+	len = SCM_ROLENGTH (dir);
+	memcpy (buf, SCM_ROCHARS (dir), len);
+	if (len >= 1 && buf[len - 1] != '/')
+	  buf[len++] = '/';
+	memcpy (buf + len, filename_chars, filename_len);
+	len += filename_len;
+
+	/* Try every extension.  At this point, we know the extension
+	   list is a proper, nonempty list of strings.  */
+	for (exts = extensions; SCM_NIMP (exts); exts = SCM_CDR (exts))
 	  {
+	    SCM ext = SCM_CAR (exts);
+	    int ext_len = SCM_ROLENGTH (ext);
 	    struct stat mode;
 
-	    if (stat (buf, &mode) >= 0
-		&& ! (mode.st_mode & S_IFDIR)
-		&& access (buf, R_OK) == 0)
+	    /* Concatenate the extension. */
+	    memcpy (buf + len, SCM_ROCHARS (ext), ext_len);
+	    buf[len + ext_len] = '\0';
+	    
+	    /* If the file exists at all, we should return it.  If the
+	       file is inaccessible, then that's an error.  */
+	    if (stat (buf, &mode) == 0
+		&& ! (mode.st_mode & S_IFDIR))
 	      {
-		SCM result = scm_makfromstr (buf, len, 0);
-		scm_must_free (buf);
-		SCM_ALLOW_INTS;
-		return result;
+		result = scm_makfromstr (buf, len + ext_len, 0);
+		goto end;
 	      }
 	  }
-	}
+      }
 
-      path = SCM_CDR (path);
-    }
-  
-  scm_must_free (buf);
-  SCM_ALLOW_INTS;
-  return SCM_BOOL_F;
+  end:
+    scm_must_free (buf);
+    scm_done_malloc (- buf_size);
+    SCM_ALLOW_INTS;
+    return result;
+  }
 }
+#undef FUNC_NAME
 
 
-SCM_PROC(s_sys_try_load_path, "primitive-load-path", 1, 2, 0,scm_primitive_load_path);
-SCM 
-scm_primitive_load_path (filename, case_insensitive_p, sharp)
-     SCM filename;
-     SCM case_insensitive_p;
-     SCM sharp;
+/* Search %load-path for a directory containing a file named FILENAME.
+   The file must be readable, and not a directory.
+   If we find one, return its full filename; otherwise, return #f.
+   If FILENAME is absolute, return it unchanged.  */
+SCM_DEFINE(scm_sys_search_load_path, "%search-load-path", 1, 0, 0, 
+           (SCM filename),
+"Search @var{%load-path} for @var{file}, which must be readable by the
+current user.  If @var{file} is found in the list of paths to search or
+is an absolute pathname, return its full pathname.  Otherwise, return
+@code{#f}.  Filenames may have any of the optional extensions in the
+@code{%load-extensions} list; @code{%search-load-path} will try each
+extension automatically.")
+#define FUNC_NAME s_scm_sys_search_load_path
 {
-  SCM full_filename = scm_sys_search_load_path (filename);
+  SCM path = *scm_loc_load_path;
+  SCM exts = *scm_loc_load_extensions;
+  SCM_VALIDATE_ROSTRING(1,filename);
+
+  SCM_ASSERT (scm_ilength (path) >= 0, path, "load path is not a proper list",
+	      FUNC_NAME);
+  SCM_ASSERT (scm_ilength (exts) >= 0, exts,
+	      "load extension list is not a proper list",
+	      FUNC_NAME);
+  return scm_search_path (path, filename, exts);
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE(scm_primitive_load_path, "primitive-load-path", 1, 0, 0, 
+           (SCM filename),
+"Search @var{%load-path} for @var{file} and load it into the top-level
+environment.  If @var{file} is a relative pathname and is not found in
+the list of search paths, an error is signalled.")
+#define FUNC_NAME s_scm_primitive_load_path
+{
+  SCM full_filename;
+
+  SCM_VALIDATE_ROSTRING(1,filename);
+
+  full_filename = scm_sys_search_load_path (filename);
+
   if (SCM_FALSEP (full_filename))
     {
-      scm_error (scm_misc_error_key,
-		 s_sys_try_load_path,
-		 "Unable to find file %S in %S",
-		 scm_listify (filename, *scm_loc_load_path, SCM_UNDEFINED),
-		 SCM_BOOL_F);
+      int absolute = (SCM_ROLENGTH (filename) >= 1
+		      && SCM_ROCHARS (filename)[0] == '/');
+      scm_misc_error (FUNC_NAME,
+		      (absolute
+		       ? "Unable to load file %S"
+		       : "Unable to find file %S in load path"),
+		      scm_listify (filename, SCM_UNDEFINED));
     }
-  return scm_primitive_load (full_filename, case_insensitive_p, sharp);
+
+  return scm_primitive_load (full_filename);
 }
+#undef FUNC_NAME
+
+/* The following function seems trivial - and indeed it is.  Its
+ * existence is motivated by its ability to evaluate expressions
+ * without copying them first (as is done in "eval").
+ */
+
+SCM_SYMBOL (scm_end_of_file_key, "end-of-file");
+
+SCM_DEFINE (scm_read_and_eval_x, "read-and-eval!", 0, 1, 0, 
+            (SCM port),
+"Read a form from @var{port} (standard input by default), and evaluate it
+(memoizing it in the process) in the top-level environment.  If no data
+is left to be read from @var{port}, an @code{end-of-file} error is
+signalled.")
+#define FUNC_NAME s_scm_read_and_eval_x
+{
+  SCM form = scm_read (port);
+  if (SCM_EOF_OBJECT_P (form))
+    scm_ithrow (scm_end_of_file_key, SCM_EOL, 1);
+  return scm_eval_x (form);
+}
+#undef FUNC_NAME
 
 
+/* Information about the build environment.  */
 
+/* Initialize the scheme variable %guile-build-info, based on data
+   provided by the Makefile, via libpath.h.  */
+static void
+init_build_info ()
+{
+  static struct { char *name; char *value; } info[] = SCM_BUILD_INFO;
+  SCM *loc = SCM_CDRLOC (scm_sysintern ("%guile-build-info", SCM_EOL));
+  unsigned int i;
+
+  for (i = 0; i < (sizeof (info) / sizeof (info[0])); i++)
+    *loc = scm_acons (SCM_CAR (scm_intern0 (info[i].name)),
+		      scm_makfrom0str (info[i].value),
+		      *loc);
+}
+
+
+
 void
 scm_init_load ()
 {
-  scm_loc_load_path = &SCM_CDR(scm_sysintern("%load-path", SCM_EOL));
+  scm_listofnullstr = scm_permanent_object (SCM_LIST1 (scm_nullstr));
+  scm_loc_load_path = SCM_CDRLOC (scm_sysintern ("%load-path", SCM_EOL));
+  scm_loc_load_extensions
+    = SCM_CDRLOC (scm_sysintern ("%load-extensions",
+				 scm_listify (scm_makfrom0str (".scm"),
+					      scm_makfrom0str (""),
+					      SCM_UNDEFINED)));
+  scm_loc_load_hook = SCM_CDRLOC (scm_sysintern ("%load-hook", SCM_BOOL_F));
+
+  init_build_info ();
 
 #include "load.x"
 }