libguile/objcodes.c

   1 /* Copyright (C) 2001, 2009 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 #if HAVE_CONFIG_H
  20 #  include <config.h>
  21 #endif
  22
  23 #include <string.h>
  24 #include <fcntl.h>
  25 #include <unistd.h>
  26 #include <sys/mman.h>
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29 #include <assert.h>
  30
  31 #include "_scm.h"
  32 #include "vm-bootstrap.h"
  33 #include "programs.h"
  34 #include "objcodes.h"
  35
  36 /* SCM_OBJCODE_COOKIE is defined in _scm.h */
  37 /* The length of the header must be a multiple of 8 bytes.  */
  38 verify (((sizeof (SCM_OBJCODE_COOKIE) - 1) & 7) == 0);
  39
  40 \f
  41 /*
  42  * Objcode type
  43  */
  44
  45 scm_t_bits scm_tc16_objcode;
  46
  47 static SCM
  48 make_objcode_by_mmap (int fd)
  49 #define FUNC_NAME "make_objcode_by_mmap"
  50 {
  51   int ret;
  52   char *addr;
  53   struct stat st;
  54   SCM sret = SCM_BOOL_F;
  55   struct scm_objcode *data;
  56
  57   ret = fstat (fd, &st);
  58   if (ret < 0)
  59     SCM_SYSERROR;
  60
  61   if (st.st_size <= sizeof (struct scm_objcode) + strlen (SCM_OBJCODE_COOKIE))
  62     scm_misc_error (FUNC_NAME, "object file too small (~a bytes)",
  63                     scm_list_1 (SCM_I_MAKINUM (st.st_size)));
  64
  65   addr = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
  66   if (addr == MAP_FAILED)
  67     {
  68       (void) close (fd);
  69       SCM_SYSERROR;
  70     }
  71
  72   if (memcmp (addr, SCM_OBJCODE_COOKIE, strlen (SCM_OBJCODE_COOKIE)))
  73     {
  74       SCM args = scm_list_1 (scm_from_locale_stringn
  75                              (addr, strlen (SCM_OBJCODE_COOKIE)));
  76       (void) close (fd);
  77       (void) munmap (addr, st.st_size);
  78       scm_misc_error (FUNC_NAME, "bad header on object file: ~s", args);
  79     }
  80
  81   data = (struct scm_objcode*)(addr + strlen (SCM_OBJCODE_COOKIE));
  82
  83   if (data->len + data->metalen != (st.st_size - sizeof (*data) - strlen (SCM_OBJCODE_COOKIE)))
  84     {
  85       (void) close (fd);
  86       (void) munmap (addr, st.st_size);
  87       scm_misc_error (FUNC_NAME, "bad length header (~a, ~a)",
  88                       scm_list_2 (scm_from_size_t (st.st_size),
  89                                   scm_from_uint32 (sizeof (*data) + data->len
  90                                                    + data->metalen)));
  91     }
  92
  93   SCM_NEWSMOB3 (sret, scm_tc16_objcode, addr + strlen (SCM_OBJCODE_COOKIE),
  94                 SCM_PACK (SCM_BOOL_F), fd);
  95   SCM_SET_SMOB_FLAGS (sret, SCM_F_OBJCODE_IS_MMAP);
  96
  97   /* FIXME: we leak ourselves and the file descriptor. but then again so does
  98      dlopen(). */
  99   return scm_permanent_object (sret);
 100 }
 101 #undef FUNC_NAME
 102
 103 SCM
 104 scm_c_make_objcode_slice (SCM parent, const scm_t_uint8 *ptr)
 105 #define FUNC_NAME "make-objcode-slice"
 106 {
 107   const struct scm_objcode *data, *parent_data;
 108   SCM ret;
 109
 110   SCM_VALIDATE_OBJCODE (1, parent);
 111   parent_data = SCM_OBJCODE_DATA (parent);
 112
 113   if (ptr < parent_data->base
 114       || ptr >= (parent_data->base + parent_data->len + parent_data->metalen
 115                  - sizeof (struct scm_objcode)))
 116     scm_misc_error (FUNC_NAME, "offset out of bounds (~a vs ~a + ~a + ~a)",
 117                     scm_list_4 (scm_from_ulong ((unsigned long)ptr),
 118                                 scm_from_ulong ((unsigned long)parent_data->base),
 119                                 scm_from_uint32 (parent_data->len),
 120                                 scm_from_uint32 (parent_data->metalen)));
 121
 122 #ifdef __GNUC__ /* we need `__alignof__' */
 123   /* Make sure bytecode for the objcode-meta is suitable aligned.  Failing to
 124      do so leads to SIGBUS/SIGSEGV on some arches (e.g., SPARC).  */
 125   assert ((((scm_t_bits) ptr) & (__alignof__ (struct scm_objcode) - 1UL)) == 0);
 126 #endif
 127
 128   data = (struct scm_objcode*)ptr;
 129   if (data->base + data->len + data->metalen > parent_data->base + parent_data->len + parent_data->metalen)
 130     abort ();
 131
 132   SCM_NEWSMOB2 (ret, scm_tc16_objcode, data, parent);
 133   SCM_SET_SMOB_FLAGS (ret, SCM_F_OBJCODE_IS_SLICE);
 134   return ret;
 135 }
 136 #undef FUNC_NAME
 137
 138 static SCM
 139 objcode_mark (SCM obj)
 140 {
 141   return SCM_SMOB_OBJECT_2 (obj);
 142 }
 143
 144 \f
 145 /*
 146  * Scheme interface
 147  */
 148
 149 SCM_DEFINE (scm_objcode_p, "objcode?", 1, 0, 0,
 150             (SCM obj),
 151             "")
 152 #define FUNC_NAME s_scm_objcode_p
 153 {
 154   return SCM_BOOL (SCM_OBJCODE_P (obj));
 155 }
 156 #undef FUNC_NAME
 157
 158 SCM_DEFINE (scm_objcode_meta, "objcode-meta", 1, 0, 0,
 159             (SCM objcode),
 160             "")
 161 #define FUNC_NAME s_scm_objcode_meta
 162 {
 163   SCM_VALIDATE_OBJCODE (1, objcode);
 164
 165   if (SCM_OBJCODE_META_LEN (objcode) == 0)
 166     return SCM_BOOL_F;
 167   else
 168     return scm_c_make_objcode_slice (objcode, (SCM_OBJCODE_BASE (objcode)
 169                                                + SCM_OBJCODE_LEN (objcode)));
 170 }
 171 #undef FUNC_NAME
 172
 173 SCM_DEFINE (scm_bytecode_to_objcode, "bytecode->objcode", 1, 0, 0,
 174             (SCM bytecode),
 175             "")
 176 #define FUNC_NAME s_scm_bytecode_to_objcode
 177 {
 178   size_t size;
 179   ssize_t increment;
 180   scm_t_array_handle handle;
 181   const scm_t_uint8 *c_bytecode;
 182   struct scm_objcode *data;
 183   SCM objcode;
 184
 185   if (scm_is_false (scm_u8vector_p (bytecode)))
 186     scm_wrong_type_arg (FUNC_NAME, 1, bytecode);
 187
 188   c_bytecode = scm_u8vector_elements (bytecode, &handle, &size, &increment);
 189   data = (struct scm_objcode*)c_bytecode;
 190   SCM_NEWSMOB2 (objcode, scm_tc16_objcode, data, bytecode);
 191   scm_array_handle_release (&handle);
 192
 193   SCM_ASSERT_RANGE (0, bytecode, size >= sizeof(struct scm_objcode));
 194   if (data->len + data->metalen != (size - sizeof (*data)))
 195     scm_misc_error (FUNC_NAME, "bad u8vector size (~a != ~a)",
 196                     scm_list_2 (scm_from_size_t (size),
 197                                 scm_from_uint32 (sizeof (*data) + data->len + data->metalen)));
 198   assert (increment == 1);
 199   SCM_SET_SMOB_FLAGS (objcode, SCM_F_OBJCODE_IS_U8VECTOR);
 200
 201   /* foolishly, we assume that as long as bytecode is around, that c_bytecode
 202      will be of the same length; perhaps a bad assumption? */
 203
 204   return objcode;
 205 }
 206 #undef FUNC_NAME
 207
 208 SCM_DEFINE (scm_load_objcode, "load-objcode", 1, 0, 0,
 209             (SCM file),
 210             "")
 211 #define FUNC_NAME s_scm_load_objcode
 212 {
 213   int fd;
 214   char *c_file;
 215
 216   SCM_VALIDATE_STRING (1, file);
 217
 218   c_file = scm_to_locale_string (file);
 219   fd = open (c_file, O_RDONLY);
 220   free (c_file);
 221   if (fd < 0) SCM_SYSERROR;
 222
 223   return make_objcode_by_mmap (fd);
 224 }
 225 #undef FUNC_NAME
 226
 227 SCM_DEFINE (scm_objcode_to_bytecode, "objcode->bytecode", 1, 0, 0,
 228             (SCM objcode),
 229             "")
 230 #define FUNC_NAME s_scm_objcode_to_bytecode
 231 {
 232   scm_t_uint8 *u8vector;
 233   scm_t_uint32 len;
 234
 235   SCM_VALIDATE_OBJCODE (1, objcode);
 236
 237   len = sizeof(struct scm_objcode) + SCM_OBJCODE_TOTAL_LEN (objcode);
 238   /* FIXME:  Is `gc_malloc' ok here? */
 239   u8vector = scm_gc_malloc (len, "objcode-u8vector");
 240   memcpy (u8vector, SCM_OBJCODE_DATA (objcode), len);
 241
 242   return scm_take_u8vector (u8vector, len);
 243 }
 244 #undef FUNC_NAME
 245
 246 SCM_DEFINE (scm_write_objcode, "write-objcode", 2, 0, 0,
 247             (SCM objcode, SCM port),
 248             "")
 249 #define FUNC_NAME s_scm_write_objcode
 250 {
 251   SCM_VALIDATE_OBJCODE (1, objcode);
 252   SCM_VALIDATE_OUTPUT_PORT (2, port);
 253
 254   scm_c_write (port, SCM_OBJCODE_COOKIE, strlen (SCM_OBJCODE_COOKIE));
 255   scm_c_write (port, SCM_OBJCODE_DATA (objcode),
 256                sizeof (struct scm_objcode) + SCM_OBJCODE_TOTAL_LEN (objcode));
 257
 258   return SCM_UNSPECIFIED;
 259 }
 260 #undef FUNC_NAME
 261
 262 \f
 263 void
 264 scm_bootstrap_objcodes (void)
 265 {
 266   scm_tc16_objcode = scm_make_smob_type ("objcode", 0);
 267   scm_set_smob_mark (scm_tc16_objcode, objcode_mark);
 268   scm_c_register_extension ("libguile", "scm_init_objcodes",
 269                             (scm_t_extension_init_func)scm_init_objcodes, NULL);
 270 }
 271
 272 /* Before, we used __BYTE_ORDER, but that is not defined on all
 273    systems. So punt and use automake, PDP endianness be damned. */
 274 #ifdef WORDS_BIGENDIAN
 275 #define SCM_BYTE_ORDER 4321
 276 #else
 277 #define SCM_BYTE_ORDER 1234
 278 #endif
 279
 280 void
 281 scm_init_objcodes (void)
 282 {
 283   scm_bootstrap_vm ();
 284
 285 #ifndef SCM_MAGIC_SNARFER
 286 #include "libguile/objcodes.x"
 287 #endif
 288
 289   scm_c_define ("word-size", scm_from_size_t (sizeof(SCM)));
 290   scm_c_define ("byte-order", scm_from_uint16 (SCM_BYTE_ORDER));
 291 }
 292
 293 /*
 294   Local Variables:
 295   c-file-style: "gnu"
 296   End:
 297 */