libguile/srcprop.c

   1 /* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2006,
   2  *   2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public License
   6  * as published by the Free Software Foundation; either version 3 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301 USA
  18  */
  19
  20
  21 \f
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27
  28 #include "libguile/_scm.h"
  29 #include "libguile/async.h"
  30 #include "libguile/smob.h"
  31 #include "libguile/alist.h"
  32 #include "libguile/debug.h"
  33 #include "libguile/hashtab.h"
  34 #include "libguile/hash.h"
  35 #include "libguile/ports.h"
  36 #include "libguile/root.h"
  37 #include "libguile/weaks.h"
  38 #include "libguile/gc.h"
  39
  40 #include "libguile/validate.h"
  41 #include "libguile/srcprop.h"
  42 #include "libguile/private-options.h"
  43
  44 \f
  45 /* {Source Properties}
  46  *
  47  * Properties of source list expressions.
  48  * Four of these have special meaning:
  49  *
  50  * filename    string   The name of the source file.
  51  * copy        list     A copy of the list expression.
  52  * line        integer  The source code line number.
  53  * column      integer  The source code column number.
  54  *
  55  * Most properties above can be set by the reader.
  56  *
  57  */
  58
  59 SCM_GLOBAL_SYMBOL (scm_sym_filename, "filename");
  60 SCM_GLOBAL_SYMBOL (scm_sym_copy, "copy");
  61 SCM_GLOBAL_SYMBOL (scm_sym_line, "line");
  62 SCM_GLOBAL_SYMBOL (scm_sym_column, "column");
  63
  64 static SCM scm_source_whash;
  65 static scm_i_pthread_mutex_t source_lock = SCM_I_PTHREAD_MUTEX_INITIALIZER;
  66
  67
  68 /*
  69  *  Source properties are stored as double cells with the
  70  *  following layout:
  71
  72  * car = tag
  73  * cbr = pos
  74  * ccr = copy
  75  * cdr = alist
  76  */
  77
  78 #define SRCPROPSP(p) (SCM_SMOB_PREDICATE (scm_tc16_srcprops, (p)))
  79 #define SRCPROPPOS(p) (SCM_SMOB_DATA(p))
  80 #define SRCPROPLINE(p) (SRCPROPPOS(p) >> 12)
  81 #define SRCPROPCOL(p) (SRCPROPPOS(p) & 0x0fffL)
  82 #define SRCPROPCOPY(p) (SCM_SMOB_OBJECT_2(p))
  83 #define SRCPROPALIST(p) (SCM_SMOB_OBJECT_3(p))
  84 #define SRCPROPMAKPOS(l, c) (((l) << 12) + (c))
  85 #define SETSRCPROPPOS(p, l, c) (SCM_SET_SMOB_DATA_1 (p, SRCPROPMAKPOS (l, c)))
  86 #define SETSRCPROPLINE(p, l) SETSRCPROPPOS (p, l, SRCPROPCOL (p))
  87 #define SETSRCPROPCOL(p, c) SETSRCPROPPOS (p, SRCPROPLINE (p), c)
  88 #define SETSRCPROPCOPY(p, c) (SCM_SET_SMOB_OBJECT_2 (p, c))
  89 #define SETSRCPROPALIST(p, l) (SCM_SET_SMOB_OBJECT_3 (p, l))
  90
  91
  92 static SCM scm_srcprops_to_alist (SCM obj);
  93
  94
  95 scm_t_bits scm_tc16_srcprops;
  96
  97
  98 static int
  99 supports_source_props (SCM obj)
 100 {
 101   return SCM_NIMP (obj) && !scm_is_symbol (obj) && !scm_is_keyword (obj);
 102 }
 103
 104
 105 static int
 106 srcprops_print (SCM obj, SCM port, scm_print_state *pstate)
 107 {
 108   int writingp = SCM_WRITINGP (pstate);
 109   scm_puts ("#<srcprops ", port);
 110   SCM_SET_WRITINGP (pstate, 1);
 111   scm_iprin1 (scm_srcprops_to_alist (obj), port, pstate);
 112   SCM_SET_WRITINGP (pstate, writingp);
 113   scm_putc ('>', port);
 114   return 1;
 115 }
 116
 117
 118 /*
 119  * We remember the last file name settings, so we can share that alist
 120  * entry.  This works because scm_set_source_property_x does not use
 121  * assoc-set! for modifying the alist.
 122  *
 123  * This variable contains a protected cons, whose cdr is the cached
 124  * alist
 125  */
 126 static SCM scm_last_alist_filename;
 127
 128 SCM
 129 scm_make_srcprops (long line, int col, SCM filename, SCM copy, SCM alist)
 130 {
 131   if (!SCM_UNBNDP (filename))
 132     {
 133       SCM old_alist = alist;
 134
 135       /*
 136         have to extract the acons, and operate on that, for
 137         thread safety.
 138        */
 139       SCM last_acons = SCM_CDR (scm_last_alist_filename);
 140       if (scm_is_null (old_alist)
 141           && scm_is_eq (SCM_CDAR (last_acons), filename))
 142         {
 143           alist = last_acons;
 144         }
 145       else
 146         {
 147           alist = scm_acons (scm_sym_filename, filename, alist);
 148           if (scm_is_null (old_alist))
 149             SCM_SETCDR (scm_last_alist_filename, alist);
 150         }
 151     }
 152
 153   SCM_RETURN_NEWSMOB3 (scm_tc16_srcprops,
 154                        SRCPROPMAKPOS (line, col),
 155                        SCM_UNPACK (copy),
 156                        SCM_UNPACK (alist));
 157 }
 158
 159
 160 static SCM
 161 scm_srcprops_to_alist (SCM obj)
 162 {
 163   SCM alist = SRCPROPALIST (obj);
 164   if (!SCM_UNBNDP (SRCPROPCOPY (obj)))
 165     alist = scm_acons (scm_sym_copy, SRCPROPCOPY (obj), alist);
 166   alist = scm_acons (scm_sym_column, scm_from_int (SRCPROPCOL (obj)), alist);
 167   alist = scm_acons (scm_sym_line, scm_from_int (SRCPROPLINE (obj)), alist);
 168   return alist;
 169 }
 170
 171 SCM_DEFINE (scm_supports_source_properties_p, "supports-source-properties?", 1, 0, 0,
 172             (SCM obj),
 173             "Return #t if @var{obj} supports adding source properties,\n"
 174             "otherwise return #f.")
 175 #define FUNC_NAME s_scm_supports_source_properties_p
 176 {
 177   return scm_from_bool (supports_source_props (obj));
 178 }
 179 #undef FUNC_NAME
 180
 181 SCM_DEFINE (scm_source_properties, "source-properties", 1, 0, 0,
 182             (SCM obj),
 183             "Return the source property association list of @var{obj}.")
 184 #define FUNC_NAME s_scm_source_properties
 185 {
 186   if (SCM_IMP (obj))
 187     return SCM_EOL;
 188   else
 189     {
 190       SCM p;
 191
 192       scm_i_pthread_mutex_lock (&source_lock);
 193       p = scm_hashq_ref (scm_source_whash, obj, SCM_EOL);
 194       scm_i_pthread_mutex_unlock (&source_lock);
 195
 196       if (SRCPROPSP (p))
 197         return scm_srcprops_to_alist (p);
 198       else
 199         /* list from set-source-properties!, or SCM_EOL for not found */
 200         return p;
 201     }
 202 }
 203 #undef FUNC_NAME
 204
 205 /* Perhaps this procedure should look through an alist
 206    and try to make a srcprops-object...? */
 207 SCM_DEFINE (scm_set_source_properties_x, "set-source-properties!", 2, 0, 0,
 208             (SCM obj, SCM alist),
 209             "Install the association list @var{alist} as the source property\n"
 210             "list for @var{obj}.")
 211 #define FUNC_NAME s_scm_set_source_properties_x
 212 {
 213   SCM_VALIDATE_NIM (1, obj);
 214
 215   scm_i_pthread_mutex_lock (&source_lock);
 216   scm_hashq_set_x (scm_source_whash, obj, alist);
 217   scm_i_pthread_mutex_unlock (&source_lock);
 218
 219   return alist;
 220 }
 221 #undef FUNC_NAME
 222
 223 int
 224 scm_i_has_source_properties (SCM obj)
 225 #define FUNC_NAME "%set-source-properties"
 226 {
 227   if (SCM_IMP (obj))
 228     return 0;
 229   else
 230     {
 231       int ret;
 232
 233       scm_i_pthread_mutex_lock (&source_lock);
 234       ret = scm_is_true (scm_hashq_ref (scm_source_whash, obj, SCM_BOOL_F));
 235       scm_i_pthread_mutex_unlock (&source_lock);
 236
 237       return ret;
 238     }
 239 }
 240 #undef FUNC_NAME
 241
 242
 243 void
 244 scm_i_set_source_properties_x (SCM obj, long line, int col, SCM fname)
 245 #define FUNC_NAME "%set-source-properties"
 246 {
 247   SCM_VALIDATE_NIM (1, obj);
 248
 249   scm_i_pthread_mutex_lock (&source_lock);
 250   scm_hashq_set_x (scm_source_whash, obj,
 251                    scm_make_srcprops (line, col, fname,
 252                                       SCM_COPY_SOURCE_P
 253                                       ? scm_copy_tree (obj)
 254                                       : SCM_UNDEFINED,
 255                                       SCM_EOL));
 256   scm_i_pthread_mutex_unlock (&source_lock);
 257 }
 258 #undef FUNC_NAME
 259
 260 SCM_DEFINE (scm_source_property, "source-property", 2, 0, 0,
 261             (SCM obj, SCM key),
 262             "Return the source property specified by @var{key} from\n"
 263             "@var{obj}'s source property list.")
 264 #define FUNC_NAME s_scm_source_property
 265 {
 266   if (SCM_IMP (obj))
 267     return SCM_BOOL_F;
 268   else
 269     {
 270       SCM p;
 271
 272       scm_i_pthread_mutex_lock (&source_lock);
 273       p = scm_hashq_ref (scm_source_whash, obj, SCM_EOL);
 274       scm_i_pthread_mutex_unlock (&source_lock);
 275
 276       if (!SRCPROPSP (p))
 277         goto alist;
 278       if (scm_is_eq (scm_sym_line, key))
 279         p = scm_from_int (SRCPROPLINE (p));
 280       else if (scm_is_eq (scm_sym_column, key))
 281         p = scm_from_int (SRCPROPCOL (p));
 282       else if (scm_is_eq (scm_sym_copy, key))
 283         p = SRCPROPCOPY (p);
 284       else
 285         {
 286           p = SRCPROPALIST (p);
 287         alist:
 288           p = scm_assoc (key, p);
 289           return (SCM_NIMP (p) ? SCM_CDR (p) : SCM_BOOL_F);
 290         }
 291       return SCM_UNBNDP (p) ? SCM_BOOL_F : p;
 292     }
 293 }
 294 #undef FUNC_NAME
 295
 296 SCM_DEFINE (scm_set_source_property_x, "set-source-property!", 3, 0, 0,
 297             (SCM obj, SCM key, SCM datum),
 298             "Set the source property of object @var{obj}, which is specified by\n"
 299             "@var{key} to @var{datum}.  Normally, the key will be a symbol.")
 300 #define FUNC_NAME s_scm_set_source_property_x
 301 {
 302   SCM p;
 303   SCM_VALIDATE_NIM (1, obj);
 304
 305   scm_i_pthread_mutex_lock (&source_lock);
 306   p = scm_hashq_ref (scm_source_whash, obj, SCM_EOL);
 307
 308   if (scm_is_eq (scm_sym_line, key))
 309     {
 310       if (SRCPROPSP (p))
 311         SETSRCPROPLINE (p, scm_to_int (datum));
 312       else
 313         scm_hashq_set_x (scm_source_whash, obj,
 314                          scm_make_srcprops (scm_to_int (datum), 0,
 315                                             SCM_UNDEFINED, SCM_UNDEFINED, p));
 316     }
 317   else if (scm_is_eq (scm_sym_column, key))
 318     {
 319       if (SRCPROPSP (p))
 320         SETSRCPROPCOL (p, scm_to_int (datum));
 321       else
 322         scm_hashq_set_x (scm_source_whash, obj,
 323                          scm_make_srcprops (0, scm_to_int (datum),
 324                                             SCM_UNDEFINED, SCM_UNDEFINED, p));
 325     }
 326   else if (scm_is_eq (scm_sym_copy, key))
 327     {
 328       if (SRCPROPSP (p))
 329         SETSRCPROPCOPY (p, datum);
 330       else
 331         scm_hashq_set_x (scm_source_whash, obj,
 332                          scm_make_srcprops (0, 0, SCM_UNDEFINED, datum, p));
 333     }
 334   else
 335     {
 336       if (SRCPROPSP (p))
 337         SETSRCPROPALIST (p, scm_acons (key, datum, SRCPROPALIST (p)));
 338       else
 339         scm_hashq_set_x (scm_source_whash, obj,
 340                          scm_acons (key, datum, p));
 341     }
 342   scm_i_pthread_mutex_unlock (&source_lock);
 343
 344   return SCM_UNSPECIFIED;
 345 }
 346 #undef FUNC_NAME
 347
 348
 349 SCM_DEFINE (scm_cons_source, "cons-source", 3, 0, 0,
 350             (SCM xorig, SCM x, SCM y),
 351             "Create and return a new pair whose car and cdr are @var{x} and @var{y}.\n"
 352             "Any source properties associated with @var{xorig} are also associated\n"
 353             "with the new pair.")
 354 #define FUNC_NAME s_scm_cons_source
 355 {
 356   SCM p, z;
 357   z = scm_cons (x, y);
 358   scm_i_pthread_mutex_lock (&source_lock);
 359   /* Copy source properties possibly associated with xorig. */
 360   p = scm_hashq_ref (scm_source_whash, xorig, SCM_BOOL_F);
 361   if (scm_is_true (p))
 362     scm_hashq_set_x (scm_source_whash, z, p);
 363   scm_i_pthread_mutex_unlock (&source_lock);
 364   return z;
 365 }
 366 #undef FUNC_NAME
 367
 368
 369 void
 370 scm_init_srcprop ()
 371 {
 372   scm_tc16_srcprops = scm_make_smob_type ("srcprops", 0);
 373   scm_set_smob_print (scm_tc16_srcprops, srcprops_print);
 374
 375   scm_source_whash = scm_make_weak_key_hash_table (scm_from_int (2047));
 376   scm_c_define ("source-whash", scm_source_whash);
 377
 378   scm_last_alist_filename = scm_cons (SCM_EOL,
 379                                       scm_acons (SCM_EOL, SCM_EOL, SCM_EOL));
 380
 381 #include "libguile/srcprop.x"
 382 }
 383
 384
 385 /*
 386   Local Variables:
 387   c-file-style: "gnu"
 388   End:
 389 */