sig/parse.cpp

   1 /* Cycript - Remove Execution Server and Disassembler
   2  * Copyright (C) 2009  Jay Freeman (saurik)
   3 */
   4
   5 /* Modified BSD License {{{ */
   6 /*
   7  *        Redistribution and use in source and binary
   8  * forms, with or without modification, are permitted
   9  * provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the
  12  *    above copyright notice, this list of conditions
  13  *    and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the
  15  *    above copyright notice, this list of conditions
  16  *    and the following disclaimer in the documentation
  17  *    and/or other materials provided with the
  18  *    distribution.
  19  * 3. The name of the author may not be used to endorse
  20  *    or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS''
  24  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
  25  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  34  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  35  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  36  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37 */
  38 /* }}} */
  39
  40 #ifndef _GNU_SOURCE
  41 #define _GNU_SOURCE
  42 #endif
  43
  44 #include "minimal/stdlib.h"
  45
  46 #include <apr-1/apr_strings.h>
  47
  48 #include <string.h>
  49
  50 #include "sig/parse.hpp"
  51
  52 namespace sig {
  53
  54 void Parse_(apr_pool_t *pool, struct Signature *signature, const char **name, char eos, Callback callback);
  55 struct Type *Parse_(apr_pool_t *pool, const char **name, char eos, bool named, Callback callback);
  56
  57
  58 /* XXX: I really screwed up this time */
  59 void *prealloc_(apr_pool_t *pool, void *odata, size_t osize, size_t nsize) {
  60     void *ndata = apr_palloc(pool, nsize);
  61     memcpy(ndata, odata, osize);
  62     return ndata;
  63 }
  64
  65 void Parse_(apr_pool_t *pool, struct Signature *signature, const char **name, char eos, Callback callback) {
  66     _assert(*name != NULL);
  67
  68     // XXX: this is just a stupid check :(
  69     bool named(**name == '"');
  70
  71     signature->elements = NULL;
  72     signature->count = 0;
  73
  74     for (;;) {
  75         if (**name == eos) {
  76             ++*name;
  77             return;
  78         }
  79
  80         signature->elements = (struct Element *) prealloc_(pool, signature->elements, signature->count * sizeof(struct Element), (signature->count + 1) * sizeof(struct Element));
  81         _assert(signature->elements != NULL);
  82
  83         struct Element *element = &signature->elements[signature->count++];
  84
  85         if (**name != '"')
  86             element->name = NULL;
  87         else {
  88             char *quote = strchr(++*name, '"');
  89             element->name = apr_pstrmemdup(pool, *name, quote - *name);
  90             *name = quote + 1;
  91         }
  92
  93         element->type = Parse_(pool, name, eos, named, callback);
  94
  95         if (**name < '0' || **name > '9')
  96             element->offset = _not(size_t);
  97         else {
  98             element->offset = 0;
  99
 100             do
 101                 element->offset = element->offset * 10 + (*(*name)++ - '0');
 102             while (**name >= '0' && **name <= '9');
 103         }
 104     }
 105 }
 106
 107 struct Type *Parse_(apr_pool_t *pool, const char **name, char eos, bool named, Callback callback) {
 108     char next = *(*name)++;
 109     if (next == '?')
 110         return NULL;
 111
 112     struct Type *type = (struct Type *) apr_palloc(pool, sizeof(struct Type));
 113     _assert(type != NULL);
 114     memset(type, 0, sizeof(struct Type));
 115
 116   parse:
 117     switch (next) {
 118         case '#': type->primitive = typename_P; break;
 119
 120         case '(':
 121             if (type->data.signature.count < 2)
 122                 type->primitive = struct_P;
 123             else
 124                 type->primitive = union_P;
 125             next = ')';
 126         goto aggregate;
 127
 128         case '*': type->primitive = string_P; break;
 129         case ':': type->primitive = selector_P; break;
 130
 131         case '@':
 132             if (**name == '"') {
 133                 char *quote = strchr(*name + 1, '"');
 134                 if (!named || quote[1] == eos || quote[1] == '"') {
 135                     type->name = apr_pstrmemdup(pool, *name + 1, quote - *name - 1);
 136                     *name = quote + 1;
 137                 }
 138             }
 139
 140             type->primitive = object_P;
 141         break;
 142
 143         case 'B': type->primitive = boolean_P; break;
 144         case 'C': type->primitive = uchar_P; break;
 145         case 'I': type->primitive = uint_P; break;
 146         case 'L': type->primitive = ulong_P; break;
 147         case 'Q': type->primitive = ulonglong_P; break;
 148         case 'S': type->primitive = ushort_P; break;
 149
 150         case '[':
 151             type->primitive = array_P;
 152             type->data.data.size = strtoul(*name, (char **) name, 10);
 153             type->data.data.type = Parse_(pool, name, eos, false, callback);
 154             if (**name != ']') {
 155                 printf("']' != \"%s\"\n", *name);
 156                 _assert(false);
 157             }
 158             ++*name;
 159         break;
 160
 161         case '^':
 162             type->primitive = pointer_P;
 163             if (**name == '"') {
 164                 type->data.data.type = NULL;
 165             } else {
 166                 type->data.data.type = Parse_(pool, name, eos, named, callback);
 167                 if (type->data.data.type->primitive == void_P)
 168                     type->data.data.type = NULL;
 169             }
 170         break;
 171
 172         case 'b':
 173             type->primitive = bit_P;
 174             type->data.data.size = strtoul(*name, (char **) name, 10);
 175         break;
 176
 177         case 'c': type->primitive = char_P; break;
 178         case 'd': type->primitive = double_P; break;
 179         case 'f': type->primitive = float_P; break;
 180         case 'i': type->primitive = int_P; break;
 181         case 'l': type->primitive = long_P; break;
 182         case 'q': type->primitive = longlong_P; break;
 183         case 's': type->primitive = short_P; break;
 184         case 'v': type->primitive = void_P; break;
 185
 186         case '{':
 187             type->primitive = struct_P;
 188             next = '}';
 189         goto aggregate;
 190
 191         aggregate: {
 192             char end = next;
 193             const char *begin = *name;
 194             do next = *(*name)++;
 195             while (
 196                 next != '=' &&
 197                 next != '}'
 198             );
 199             size_t length = *name - begin - 1;
 200             if (strncmp(begin, "?", length) != 0)
 201                 type->name = (char *) apr_pstrmemdup(pool, begin, length);
 202             else
 203                 type->name = NULL;
 204
 205             // XXX: this types thing is a throwback to JocStrap
 206
 207             char *types;
 208             if (next != '=') {
 209                 types = NULL;
 210             } else {
 211                 const char *temp(*name);
 212                 Parse_(pool, &type->data.signature, name, end, callback);
 213                 types = (char *) apr_pstrmemdup(pool, temp, *name - temp - 1);
 214             }
 215
 216             if (callback != NULL)
 217                 (*callback)(pool, type->name, types, type);
 218         } break;
 219
 220         case 'N': type->flags |= JOC_TYPE_INOUT; goto next;
 221         case 'n': type->flags |= JOC_TYPE_IN; goto next;
 222         case 'O': type->flags |= JOC_TYPE_BYCOPY; goto next;
 223         case 'o': type->flags |= JOC_TYPE_OUT; goto next;
 224         case 'R': type->flags |= JOC_TYPE_BYREF; goto next;
 225         case 'r': type->flags |= JOC_TYPE_CONST; goto next;
 226         case 'V': type->flags |= JOC_TYPE_ONEWAY; goto next;
 227
 228         next:
 229             next = *(*name)++;
 230             goto parse;
 231         break;
 232
 233         default:
 234             printf("invalid type character: '%c' {%s}\n", next, *name - 10);
 235             _assert(false);
 236     }
 237
 238     return type;
 239 }
 240
 241 void Parse(apr_pool_t *pool, struct Signature *signature, const char *name, Callback callback) {
 242     const char *temp = name;
 243     Parse_(pool, signature, &temp, '\0', callback);
 244     _assert(temp[-1] == '\0');
 245 }
 246
 247 const char *Unparse(apr_pool_t *pool, struct Signature *signature) {
 248     const char *value = "";
 249     size_t offset;
 250
 251     for (offset = 0; offset != signature->count; ++offset) {
 252         const char *type = Unparse(pool, signature->elements[offset].type);
 253         value = apr_pstrcat(pool, value, type, NULL);
 254     }
 255
 256     return value;
 257 }
 258
 259 const char *Unparse(apr_pool_t *pool, struct Type *type) {
 260     if (type == NULL)
 261         return "?";
 262     else switch (type->primitive) {
 263         case typename_P: return "#";
 264         case union_P: return apr_psprintf(pool, "(%s)", Unparse(pool, &type->data.signature));
 265         case string_P: return "*";
 266         case selector_P: return ":";
 267         case object_P: return type->name == NULL ? "@" : apr_psprintf(pool, "@\"%s\"", type->name);
 268         case boolean_P: return "B";
 269         case uchar_P: return "C";
 270         case uint_P: return "I";
 271         case ulong_P: return "L";
 272         case ulonglong_P: return "Q";
 273         case ushort_P: return "S";
 274
 275         case array_P: {
 276             const char *value = Unparse(pool, type->data.data.type);
 277             return apr_psprintf(pool, "[%lu%s]", type->data.data.size, value);
 278         } break;
 279
 280         case pointer_P: return apr_psprintf(pool, "^%s", type->data.data.type == NULL ? "" : Unparse(pool, type->data.data.type));
 281         case bit_P: return apr_psprintf(pool, "b%zu", type->data.data.size);
 282         case char_P: return "c";
 283         case double_P: return "d";
 284         case float_P: return "f";
 285         case int_P: return "i";
 286         case long_P: return "l";
 287         case longlong_P: return "q";
 288         case short_P: return "s";
 289         case void_P: return "v";
 290         case struct_P: return apr_psprintf(pool, "{%s=%s}", type->name == NULL ? "?" : type->name, Unparse(pool, &type->data.signature));
 291     }
 292
 293     _assert(false);
 294     return NULL;
 295 }
 296
 297 }