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 #include <apr_strings.h>
  41 #include "sig/parse.hpp"
  42 #include "Error.hpp"
  43
  44 #include <cstdio>
  45 #include <cstdlib>
  46 #include <cstring>
  47
  48 namespace sig {
  49
  50 void Parse_(apr_pool_t *pool, struct Signature *signature, const char **name, char eos, Callback callback);
  51 struct Type *Parse_(apr_pool_t *pool, const char **name, char eos, bool named, Callback callback);
  52
  53
  54 /* XXX: I really screwed up this time */
  55 void *prealloc_(apr_pool_t *pool, void *odata, size_t osize, size_t nsize) {
  56     void *ndata = apr_palloc(pool, nsize);
  57     memcpy(ndata, odata, osize);
  58     return ndata;
  59 }
  60
  61 void Parse_(apr_pool_t *pool, struct Signature *signature, const char **name, char eos, Callback callback) {
  62     _assert(*name != NULL);
  63
  64     // XXX: this is just a stupid check :(
  65     bool named(**name == '"');
  66
  67     signature->elements = NULL;
  68     signature->count = 0;
  69
  70     for (;;) {
  71         if (**name == eos) {
  72             ++*name;
  73             return;
  74         }
  75
  76         signature->elements = (struct Element *) prealloc_(pool, signature->elements, signature->count * sizeof(struct Element), (signature->count + 1) * sizeof(struct Element));
  77         _assert(signature->elements != NULL);
  78
  79         struct Element *element = &signature->elements[signature->count++];
  80
  81         if (**name != '"')
  82             element->name = NULL;
  83         else {
  84             char *quote = strchr(++*name, '"');
  85             element->name = apr_pstrmemdup(pool, *name, quote - *name);
  86             *name = quote + 1;
  87         }
  88
  89         element->type = Parse_(pool, name, eos, named, callback);
  90
  91         if (**name < '0' || **name > '9')
  92             element->offset = _not(size_t);
  93         else {
  94             element->offset = 0;
  95
  96             do
  97                 element->offset = element->offset * 10 + (*(*name)++ - '0');
  98             while (**name >= '0' && **name <= '9');
  99         }
 100     }
 101 }
 102
 103 struct Type *Parse_(apr_pool_t *pool, const char **name, char eos, bool named, Callback callback) {
 104     char next = *(*name)++;
 105     if (next == '?')
 106         return NULL;
 107
 108     struct Type *type = (struct Type *) apr_palloc(pool, sizeof(struct Type));
 109     _assert(type != NULL);
 110     memset(type, 0, sizeof(struct Type));
 111
 112   parse:
 113     switch (next) {
 114         case '#': type->primitive = typename_P; break;
 115
 116         case '(':
 117             if (type->data.signature.count < 2)
 118                 type->primitive = struct_P;
 119             else
 120                 type->primitive = union_P;
 121             next = ')';
 122         goto aggregate;
 123
 124         case '*': type->primitive = string_P; break;
 125         case ':': type->primitive = selector_P; break;
 126
 127         case '@':
 128             if (**name == '"') {
 129                 char *quote = strchr(*name + 1, '"');
 130                 if (!named || quote[1] == eos || quote[1] == '"') {
 131                     type->name = apr_pstrmemdup(pool, *name + 1, quote - *name - 1);
 132                     *name = quote + 1;
 133                 }
 134             }
 135
 136             type->primitive = object_P;
 137         break;
 138
 139         case 'B': type->primitive = boolean_P; break;
 140         case 'C': type->primitive = uchar_P; break;
 141         case 'I': type->primitive = uint_P; break;
 142         case 'L': type->primitive = ulong_P; break;
 143         case 'Q': type->primitive = ulonglong_P; break;
 144         case 'S': type->primitive = ushort_P; break;
 145
 146         case '[':
 147             type->primitive = array_P;
 148             type->data.data.size = strtoul(*name, (char **) name, 10);
 149             type->data.data.type = Parse_(pool, name, eos, false, callback);
 150             if (**name != ']') {
 151                 printf("']' != \"%s\"\n", *name);
 152                 _assert(false);
 153             }
 154             ++*name;
 155         break;
 156
 157         case '^':
 158             type->primitive = pointer_P;
 159             if (**name == '"') {
 160                 type->data.data.type = NULL;
 161             } else {
 162                 type->data.data.type = Parse_(pool, name, eos, named, callback);
 163                 sig::Type *&target(type->data.data.type);
 164                 if (target != NULL && target->primitive == void_P)
 165                     target = NULL;
 166             }
 167         break;
 168
 169         case 'b':
 170             type->primitive = bit_P;
 171             type->data.data.size = strtoul(*name, (char **) name, 10);
 172         break;
 173
 174         case 'c': type->primitive = char_P; break;
 175         case 'd': type->primitive = double_P; break;
 176         case 'f': type->primitive = float_P; break;
 177         case 'i': type->primitive = int_P; break;
 178         case 'l': type->primitive = long_P; break;
 179         case 'q': type->primitive = longlong_P; break;
 180         case 's': type->primitive = short_P; break;
 181         case 'v': type->primitive = void_P; break;
 182
 183         case '{':
 184             type->primitive = struct_P;
 185             next = '}';
 186         goto aggregate;
 187
 188         aggregate: {
 189             char end = next;
 190             const char *begin = *name;
 191             do next = *(*name)++;
 192             while (
 193                 next != '=' &&
 194                 next != '}'
 195             );
 196             size_t length = *name - begin - 1;
 197             if (strncmp(begin, "?", length) != 0)
 198                 type->name = (char *) apr_pstrmemdup(pool, begin, length);
 199             else
 200                 type->name = NULL;
 201
 202             // XXX: this types thing is a throwback to JocStrap
 203
 204             if (next == '=')
 205                 Parse_(pool, &type->data.signature, name, end, callback);
 206         } break;
 207
 208         case 'N': type->flags |= JOC_TYPE_INOUT; goto next;
 209         case 'n': type->flags |= JOC_TYPE_IN; goto next;
 210         case 'O': type->flags |= JOC_TYPE_BYCOPY; goto next;
 211         case 'o': type->flags |= JOC_TYPE_OUT; goto next;
 212         case 'R': type->flags |= JOC_TYPE_BYREF; goto next;
 213         case 'r': type->flags |= JOC_TYPE_CONST; goto next;
 214         case 'V': type->flags |= JOC_TYPE_ONEWAY; goto next;
 215
 216         next:
 217             next = *(*name)++;
 218             goto parse;
 219         break;
 220
 221         default:
 222             printf("invalid type character: '%c' {%s}\n", next, *name - 10);
 223             _assert(false);
 224     }
 225
 226     if (callback != NULL)
 227         (*callback)(pool, type);
 228
 229     return type;
 230 }
 231
 232 void Parse(apr_pool_t *pool, struct Signature *signature, const char *name, Callback callback) {
 233     const char *temp = name;
 234     Parse_(pool, signature, &temp, '\0', callback);
 235     _assert(temp[-1] == '\0');
 236 }
 237
 238 const char *Unparse(apr_pool_t *pool, struct Signature *signature) {
 239     const char *value = "";
 240     size_t offset;
 241
 242     for (offset = 0; offset != signature->count; ++offset) {
 243         const char *type = Unparse(pool, signature->elements[offset].type);
 244         value = apr_pstrcat(pool, value, type, NULL);
 245     }
 246
 247     return value;
 248 }
 249
 250 const char *Unparse(apr_pool_t *pool, struct Type *type) {
 251     if (type == NULL)
 252         return "?";
 253     else switch (type->primitive) {
 254         case typename_P: return "#";
 255         case union_P: return apr_psprintf(pool, "(%s)", Unparse(pool, &type->data.signature));
 256         case string_P: return "*";
 257         case selector_P: return ":";
 258         case object_P: return type->name == NULL ? "@" : apr_psprintf(pool, "@\"%s\"", type->name);
 259         case boolean_P: return "B";
 260         case uchar_P: return "C";
 261         case uint_P: return "I";
 262         case ulong_P: return "L";
 263         case ulonglong_P: return "Q";
 264         case ushort_P: return "S";
 265
 266         case array_P: {
 267             const char *value = Unparse(pool, type->data.data.type);
 268             return apr_psprintf(pool, "[%zu%s]", type->data.data.size, value);
 269         } break;
 270
 271         case pointer_P: return apr_psprintf(pool, "^%s", type->data.data.type == NULL ? "v" : Unparse(pool, type->data.data.type));
 272         case bit_P: return apr_psprintf(pool, "b%zu", type->data.data.size);
 273         case char_P: return "c";
 274         case double_P: return "d";
 275         case float_P: return "f";
 276         case int_P: return "i";
 277         case long_P: return "l";
 278         case longlong_P: return "q";
 279         case short_P: return "s";
 280         case void_P: return "v";
 281         case struct_P: return apr_psprintf(pool, "{%s=%s}", type->name == NULL ? "?" : type->name, Unparse(pool, &type->data.signature));
 282     }
 283
 284     _assert(false);
 285     return NULL;
 286 }
 287
 288 }