libguile/inline.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_INLINE_H
   4 #define SCM_INLINE_H
   5
   6 /* Copyright (C) 2001, 2002, 2003, 2004, 2006, 2008 Free Software Foundation, Inc.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /* This file is for inline functions.  On platforms that don't support
  24    inlining functions, they are turned into ordinary functions.  See
  25    "inline.c".
  26 */
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30
  31 #include "libguile/__scm.h"
  32
  33 #include "libguile/pairs.h"
  34 #include "libguile/gc.h"
  35 #include "libguile/threads.h"
  36 #include "libguile/unif.h"
  37 #include "libguile/ports.h"
  38 #include "libguile/error.h"
  39
  40
  41 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
  42
  43 /* GCC has `__inline__' in all modes, including strict ansi.  GCC 4.3 and
  44    above with `-std=c99' or `-std=gnu99' implements ISO C99 inline semantics,
  45    unless `-fgnu89-inline' is used.  Here we want GNU "extern inline"
  46    semantics, hence the `__gnu_inline__' attribute, in accordance with:
  47    http://gcc.gnu.org/gcc-4.3/porting_to.html .
  48
  49    With GCC 4.2, `__GNUC_STDC_INLINE__' is never defined (because C99 inline
  50    semantics are not supported), but a warning is issued in C99 mode if
  51    `__gnu_inline__' is not used.
  52
  53    Apple's GCC build >5400 (since Xcode 3.0) doesn't support GNU inline in
  54    C99 mode and doesn't define `__GNUC_STDC_INLINE__'.  Fall back to "static
  55    inline" in that case.  */
  56
  57 # if (defined __GNUC__) && (!(((defined __APPLE_CC__) && (__APPLE_CC__ > 5400)) && __STDC_VERSION__ >= 199901L))
  58 #  define SCM_C_USE_EXTERN_INLINE 1
  59 #  if (defined __GNUC_STDC_INLINE__) || (__GNUC__ == 4 && __GNUC_MINOR__ == 2)
  60 #   define SCM_C_EXTERN_INLINE                                  \
  61            extern __inline__ __attribute__ ((__gnu_inline__))
  62 #  else
  63 #   define SCM_C_EXTERN_INLINE extern __inline__
  64 #  endif
  65 # elif (defined SCM_C_INLINE)
  66 #  define SCM_C_EXTERN_INLINE static SCM_C_INLINE
  67 # endif
  68
  69 #endif /* SCM_INLINE_C_INCLUDING_INLINE_H */
  70
  71
  72 #if (!defined SCM_C_INLINE) || (defined SCM_INLINE_C_INCLUDING_INLINE_H) \
  73     || (defined SCM_C_USE_EXTERN_INLINE)
  74
  75 /* The `extern' declarations.  They should only appear when used from
  76    "inline.c", when `inline' is not supported at all or when "extern inline"
  77    is used.  */
  78
  79 #include "libguile/boehm-gc.h"
  80
  81
  82 SCM_API SCM scm_cell (scm_t_bits car, scm_t_bits cdr);
  83 SCM_API SCM scm_immutable_cell (scm_t_bits car, scm_t_bits cdr);
  84 SCM_API SCM scm_double_cell (scm_t_bits car, scm_t_bits cbr,
  85                              scm_t_bits ccr, scm_t_bits cdr);
  86 SCM_API SCM scm_immutable_double_cell (scm_t_bits car, scm_t_bits cbr,
  87                                        scm_t_bits ccr, scm_t_bits cdr);
  88
  89 SCM_API SCM scm_array_handle_ref (scm_t_array_handle *h, ssize_t pos);
  90 SCM_API void scm_array_handle_set (scm_t_array_handle *h, ssize_t pos, SCM val);
  91
  92 SCM_API int scm_is_pair (SCM x);
  93
  94 SCM_API int scm_getc (SCM port);
  95 SCM_API void scm_putc (char c, SCM port);
  96 SCM_API void scm_puts (const char *str_data, SCM port);
  97
  98 #endif
  99
 100
 101 #if defined SCM_C_EXTERN_INLINE || defined SCM_INLINE_C_INCLUDING_INLINE_H
 102 /* either inlining, or being included from inline.c.  We use (and
 103    repeat) this long #if test here and below so that we don't have to
 104    introduce any extraneous symbols into the public namespace.  We
 105    only need SCM_C_INLINE to be seen publically . */
 106
 107 extern unsigned scm_newcell2_count;
 108 extern unsigned scm_newcell_count;
 109
 110
 111 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 112 SCM_C_EXTERN_INLINE
 113 #endif
 114
 115 SCM
 116 scm_cell (scm_t_bits car, scm_t_bits cdr)
 117 {
 118   SCM cell = SCM_PACK ((scm_t_bits) (GC_MALLOC (sizeof (scm_t_cell))));
 119
 120   /* Initialize the type slot last so that the cell is ignored by the GC
 121      until it is completely initialized.  This is only relevant when the GC
 122      can actually run during this code, which it can't since the GC only runs
 123      when all other threads are stopped.  */
 124   SCM_GC_SET_CELL_WORD (cell, 1, cdr);
 125   SCM_GC_SET_CELL_WORD (cell, 0, car);
 126
 127   return cell;
 128 }
 129
 130 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 131 SCM_C_EXTERN_INLINE
 132 #endif
 133 SCM
 134 scm_immutable_cell (scm_t_bits car, scm_t_bits cdr)
 135 {
 136   SCM cell = SCM_PACK ((scm_t_bits) (GC_MALLOC_STUBBORN (sizeof (scm_t_cell))));
 137
 138   /* Initialize the type slot last so that the cell is ignored by the GC
 139      until it is completely initialized.  This is only relevant when the GC
 140      can actually run during this code, which it can't since the GC only runs
 141      when all other threads are stopped.  */
 142   SCM_GC_SET_CELL_WORD (cell, 1, cdr);
 143   SCM_GC_SET_CELL_WORD (cell, 0, car);
 144
 145   GC_END_STUBBORN_CHANGE ((void *) cell);
 146
 147   return cell;
 148 }
 149
 150 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 151 SCM_C_EXTERN_INLINE
 152 #endif
 153 SCM
 154 scm_double_cell (scm_t_bits car, scm_t_bits cbr,
 155                  scm_t_bits ccr, scm_t_bits cdr)
 156 {
 157   SCM z;
 158
 159   z = SCM_PACK ((scm_t_bits) (GC_MALLOC (2 * sizeof (scm_t_cell))));
 160   /* Initialize the type slot last so that the cell is ignored by the
 161      GC until it is completely initialized.  This is only relevant
 162      when the GC can actually run during this code, which it can't
 163      since the GC only runs when all other threads are stopped.
 164   */
 165   SCM_GC_SET_CELL_WORD (z, 1, cbr);
 166   SCM_GC_SET_CELL_WORD (z, 2, ccr);
 167   SCM_GC_SET_CELL_WORD (z, 3, cdr);
 168   SCM_GC_SET_CELL_WORD (z, 0, car);
 169
 170   /* When this function is inlined, it's possible that the last
 171      SCM_GC_SET_CELL_WORD above will be adjacent to a following
 172      initialization of z.  E.g., it occurred in scm_make_real.  GCC
 173      from around version 3 (e.g., certainly 3.2) began taking
 174      advantage of strict C aliasing rules which say that it's OK to
 175      interchange the initialization above and the one below when the
 176      pointer types appear to differ sufficiently.  We don't want that,
 177      of course.  GCC allows this behaviour to be disabled with the
 178      -fno-strict-aliasing option, but would also need to be supplied
 179      by Guile users.  Instead, the following statements prevent the
 180      reordering.
 181    */
 182 #ifdef __GNUC__
 183   __asm__ volatile ("" : : : "memory");
 184 #else
 185   /* portable version, just in case any other compiler does the same
 186      thing.  */
 187   scm_remember_upto_here_1 (z);
 188 #endif
 189
 190   return z;
 191 }
 192
 193 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 194 SCM_C_EXTERN_INLINE
 195 #endif
 196 SCM
 197 scm_immutable_double_cell (scm_t_bits car, scm_t_bits cbr,
 198                            scm_t_bits ccr, scm_t_bits cdr)
 199 {
 200   SCM z;
 201
 202   z = SCM_PACK ((scm_t_bits) (GC_MALLOC_STUBBORN (2 * sizeof (scm_t_cell))));
 203   /* Initialize the type slot last so that the cell is ignored by the
 204      GC until it is completely initialized.  This is only relevant
 205      when the GC can actually run during this code, which it can't
 206      since the GC only runs when all other threads are stopped.
 207   */
 208   SCM_GC_SET_CELL_WORD (z, 1, cbr);
 209   SCM_GC_SET_CELL_WORD (z, 2, ccr);
 210   SCM_GC_SET_CELL_WORD (z, 3, cdr);
 211   SCM_GC_SET_CELL_WORD (z, 0, car);
 212
 213   GC_END_STUBBORN_CHANGE ((void *) z);
 214
 215   /* When this function is inlined, it's possible that the last
 216      SCM_GC_SET_CELL_WORD above will be adjacent to a following
 217      initialization of z.  E.g., it occurred in scm_make_real.  GCC
 218      from around version 3 (e.g., certainly 3.2) began taking
 219      advantage of strict C aliasing rules which say that it's OK to
 220      interchange the initialization above and the one below when the
 221      pointer types appear to differ sufficiently.  We don't want that,
 222      of course.  GCC allows this behaviour to be disabled with the
 223      -fno-strict-aliasing option, but would also need to be supplied
 224      by Guile users.  Instead, the following statements prevent the
 225      reordering.
 226    */
 227 #ifdef __GNUC__
 228   __asm__ volatile ("" : : : "memory");
 229 #else
 230   /* portable version, just in case any other compiler does the same
 231      thing.  */
 232   scm_remember_upto_here_1 (z);
 233 #endif
 234
 235   return z;
 236 }
 237
 238 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 239 SCM_C_EXTERN_INLINE
 240 #endif
 241 SCM
 242 scm_array_handle_ref (scm_t_array_handle *h, ssize_t p)
 243 {
 244   return h->ref (h, p);
 245 }
 246
 247 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 248 SCM_C_EXTERN_INLINE
 249 #endif
 250 void
 251 scm_array_handle_set (scm_t_array_handle *h, ssize_t p, SCM v)
 252 {
 253   h->set (h, p, v);
 254 }
 255
 256 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 257 SCM_C_EXTERN_INLINE
 258 #endif
 259 int
 260 scm_is_pair (SCM x)
 261 {
 262   /* The following "workaround_for_gcc_295" avoids bad code generated by
 263      i386 gcc 2.95.4 (the Debian packaged 2.95.4-24 at least).
 264
 265      Under the default -O2 the inlined SCM_I_CONSP test gets "optimized" so
 266      the fetch of the tag word from x is done before confirming it's a
 267      non-immediate (SCM_NIMP).  Needless to say that bombs badly if x is a
 268      immediate.  This was seen to afflict scm_srfi1_split_at and something
 269      deep in the bowels of ceval().  In both cases segvs resulted from
 270      deferencing a random immediate value.  srfi-1.test exposes the problem
 271      through a short list, the immediate being SCM_EOL in that case.
 272      Something in syntax.test exposed the ceval() problem.
 273
 274      Just "volatile SCM workaround_for_gcc_295 = lst" is enough to avoid the
 275      problem, without even using that variable.  The "w=w" is just to
 276      prevent a warning about it being unused.
 277      */
 278 #if defined (__GNUC__) && __GNUC__ == 2 && __GNUC_MINOR__ == 95
 279   volatile SCM workaround_for_gcc_295 = x;
 280   workaround_for_gcc_295 = workaround_for_gcc_295;
 281 #endif
 282
 283   return SCM_I_CONSP (x);
 284 }
 285
 286
 287 /* Port I/O.  */
 288
 289 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 290 SCM_C_EXTERN_INLINE
 291 #endif
 292 int
 293 scm_getc (SCM port)
 294 {
 295   int c;
 296   scm_t_port *pt = SCM_PTAB_ENTRY (port);
 297
 298   if (pt->rw_active == SCM_PORT_WRITE)
 299     /* may be marginally faster than calling scm_flush.  */
 300     scm_ptobs[SCM_PTOBNUM (port)].flush (port);
 301
 302   if (pt->rw_random)
 303     pt->rw_active = SCM_PORT_READ;
 304
 305   if (pt->read_pos >= pt->read_end)
 306     {
 307       if (scm_fill_input (port) == EOF)
 308         return EOF;
 309     }
 310
 311   c = *(pt->read_pos++);
 312
 313   switch (c)
 314     {
 315       case '\a':
 316         break;
 317       case '\b':
 318         SCM_DECCOL (port);
 319         break;
 320       case '\n':
 321         SCM_INCLINE (port);
 322         break;
 323       case '\r':
 324         SCM_ZEROCOL (port);
 325         break;
 326       case '\t':
 327         SCM_TABCOL (port);
 328         break;
 329       default:
 330         SCM_INCCOL (port);
 331         break;
 332     }
 333
 334   return c;
 335 }
 336
 337 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 338 SCM_C_EXTERN_INLINE
 339 #endif
 340 void
 341 scm_putc (char c, SCM port)
 342 {
 343   SCM_ASSERT_TYPE (SCM_OPOUTPORTP (port), port, 0, NULL, "output port");
 344   scm_lfwrite (&c, 1, port);
 345 }
 346
 347 #ifndef SCM_INLINE_C_INCLUDING_INLINE_H
 348 SCM_C_EXTERN_INLINE
 349 #endif
 350 void
 351 scm_puts (const char *s, SCM port)
 352 {
 353   SCM_ASSERT_TYPE (SCM_OPOUTPORTP (port), port, 0, NULL, "output port");
 354   scm_lfwrite (s, strlen (s), port);
 355 }
 356
 357
 358 #endif
 359 #endif