libguile/instructions.c

   1 /* Copyright (C) 2001, 2009, 2010, 2011 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
  25 #include "_scm.h"
  26 #include "threads.h"
  27 #include "instructions.h"
  28
  29
  30 struct scm_instruction {
  31   enum scm_opcode opcode;       /* opcode */
  32   const char *name;             /* instruction name */
  33   signed char len;              /* Instruction length.  This may be -1 for
  34                                    the loader (see the `VM_LOADER'
  35                                    macro).  */
  36   signed char npop;             /* The number of values popped.  This may be
  37                                    -1 for insns like `call' which can take
  38                                    any number of arguments.  */
  39   char npush;                   /* the number of values pushed */
  40   SCM symname;                  /* filled in later */
  41 };
  42
  43 #define SCM_VALIDATE_LOOKUP_INSTRUCTION(pos, var, cvar)               \
  44   do {                                                                \
  45     cvar = scm_lookup_instruction_by_name (var);                      \
  46     SCM_ASSERT_TYPE (cvar, var, pos, FUNC_NAME, "INSTRUCTION_P");     \
  47   } while (0)
  48
  49
  50 static scm_i_pthread_mutex_t itable_lock = SCM_I_PTHREAD_MUTEX_INITIALIZER;
  51
  52
  53 static struct scm_instruction*
  54 fetch_instruction_table ()
  55 {
  56   static struct scm_instruction *table = NULL;
  57
  58   scm_i_pthread_mutex_lock (&itable_lock);
  59   if (SCM_UNLIKELY (!table))
  60     {
  61       size_t bytes = SCM_VM_NUM_INSTRUCTIONS * sizeof(struct scm_instruction);
  62       int i;
  63       table = malloc (bytes);
  64       memset (table, 0, bytes);
  65 #define VM_INSTRUCTION_TO_TABLE 1
  66 #include <libguile/vm-expand.h>
  67 #include <libguile/vm-i-system.i>
  68 #include <libguile/vm-i-scheme.i>
  69 #include <libguile/vm-i-loader.i>
  70 #undef VM_INSTRUCTION_TO_TABLE
  71       for (i = 0; i < SCM_VM_NUM_INSTRUCTIONS; i++)
  72         {
  73           table[i].opcode = i;
  74           if (table[i].name)
  75             table[i].symname = scm_from_locale_symbol (table[i].name);
  76           else
  77             table[i].symname = SCM_BOOL_F;
  78         }
  79     }
  80   scm_i_pthread_mutex_unlock (&itable_lock);
  81
  82   return table;
  83 }
  84
  85 static struct scm_instruction *
  86 scm_lookup_instruction_by_name (SCM name)
  87 {
  88   static SCM instructions_by_name = SCM_BOOL_F;
  89   struct scm_instruction *table = fetch_instruction_table ();
  90   SCM op;
  91
  92   if (SCM_UNLIKELY (scm_is_false (instructions_by_name)))
  93     {
  94       unsigned int i;
  95
  96       instructions_by_name =
  97         scm_make_hash_table (SCM_I_MAKINUM (SCM_VM_NUM_INSTRUCTIONS));
  98
  99       for (i = 0; i < SCM_VM_NUM_INSTRUCTIONS; i++)
 100         if (scm_is_true (table[i].symname))
 101           scm_hashq_set_x (instructions_by_name, table[i].symname,
 102                            SCM_I_MAKINUM (i));
 103     }
 104
 105   op = scm_hashq_ref (instructions_by_name, name, SCM_UNDEFINED);
 106   if (SCM_I_INUMP (op))
 107     return &table[SCM_I_INUM (op)];
 108
 109   return NULL;
 110 }
 111
 112
 113 /* Scheme interface */
 114
 115 SCM_DEFINE (scm_instruction_list, "instruction-list", 0, 0, 0,
 116             (void),
 117             "")
 118 #define FUNC_NAME s_scm_instruction_list
 119 {
 120   SCM list = SCM_EOL;
 121   int i;
 122   struct scm_instruction *ip = fetch_instruction_table ();
 123   for (i = 0; i < SCM_VM_NUM_INSTRUCTIONS; i++)
 124     if (ip[i].name)
 125       list = scm_cons (ip[i].symname, list);
 126   return scm_reverse_x (list, SCM_EOL);
 127 }
 128 #undef FUNC_NAME
 129
 130 SCM_DEFINE (scm_instruction_p, "instruction?", 1, 0, 0,
 131             (SCM obj),
 132             "")
 133 #define FUNC_NAME s_scm_instruction_p
 134 {
 135   return scm_from_bool (scm_lookup_instruction_by_name (obj) != NULL);
 136 }
 137 #undef FUNC_NAME
 138
 139 SCM_DEFINE (scm_instruction_length, "instruction-length", 1, 0, 0,
 140             (SCM inst),
 141             "")
 142 #define FUNC_NAME s_scm_instruction_length
 143 {
 144   struct scm_instruction *ip;
 145   SCM_VALIDATE_LOOKUP_INSTRUCTION (1, inst, ip);
 146   return SCM_I_MAKINUM (ip->len);
 147 }
 148 #undef FUNC_NAME
 149
 150 SCM_DEFINE (scm_instruction_pops, "instruction-pops", 1, 0, 0,
 151             (SCM inst),
 152             "")
 153 #define FUNC_NAME s_scm_instruction_pops
 154 {
 155   struct scm_instruction *ip;
 156   SCM_VALIDATE_LOOKUP_INSTRUCTION (1, inst, ip);
 157   return SCM_I_MAKINUM (ip->npop);
 158 }
 159 #undef FUNC_NAME
 160
 161 SCM_DEFINE (scm_instruction_pushes, "instruction-pushes", 1, 0, 0,
 162             (SCM inst),
 163             "")
 164 #define FUNC_NAME s_scm_instruction_pushes
 165 {
 166   struct scm_instruction *ip;
 167   SCM_VALIDATE_LOOKUP_INSTRUCTION (1, inst, ip);
 168   return SCM_I_MAKINUM (ip->npush);
 169 }
 170 #undef FUNC_NAME
 171
 172 SCM_DEFINE (scm_instruction_to_opcode, "instruction->opcode", 1, 0, 0,
 173             (SCM inst),
 174             "")
 175 #define FUNC_NAME s_scm_instruction_to_opcode
 176 {
 177   struct scm_instruction *ip;
 178   SCM_VALIDATE_LOOKUP_INSTRUCTION (1, inst, ip);
 179   return SCM_I_MAKINUM (ip->opcode);
 180 }
 181 #undef FUNC_NAME
 182
 183 SCM_DEFINE (scm_opcode_to_instruction, "opcode->instruction", 1, 0, 0,
 184             (SCM op),
 185             "")
 186 #define FUNC_NAME s_scm_opcode_to_instruction
 187 {
 188   scm_t_signed_bits opcode;
 189   SCM ret = SCM_BOOL_F;
 190
 191   SCM_MAKE_VALIDATE (1, op, I_INUMP);
 192   opcode = SCM_I_INUM (op);
 193
 194   if (opcode >= 0 && opcode < SCM_VM_NUM_INSTRUCTIONS)
 195     ret = fetch_instruction_table ()[opcode].symname;
 196
 197   if (scm_is_false (ret))
 198     scm_wrong_type_arg_msg (FUNC_NAME, 1, op, "INSTRUCTION_P");
 199
 200   return ret;
 201 }
 202 #undef FUNC_NAME
 203
 204 void
 205 scm_bootstrap_instructions (void)
 206 {
 207   scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION,
 208                             "scm_init_instructions",
 209                             (scm_t_extension_init_func)scm_init_instructions,
 210                             NULL);
 211 }
 212
 213 void
 214 scm_init_instructions (void)
 215 {
 216 #ifndef SCM_MAGIC_SNARFER
 217 #include "libguile/instructions.x"
 218 #endif
 219 }
 220
 221 /*
 222   Local Variables:
 223   c-file-style: "gnu"
 224   End:
 225 */