src/glsl/pp/sl_pp_if.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include "sl_pp_expression.h"
  31 #include "sl_pp_process.h"
  32
  33
  34 static int
  35 _macro_is_defined(struct sl_pp_context *context,
  36                   int macro_name)
  37 {
  38    unsigned int i;
  39    struct sl_pp_macro *macro;
  40
  41    for (i = 0; i < context->num_extensions; i++) {
  42       if (macro_name == context->extensions[i].name) {
  43          return 1;
  44       }
  45    }
  46
  47    for (macro = context->macro; macro; macro = macro->next) {
  48       if (macro_name == macro->name) {
  49          return 1;
  50       }
  51    }
  52
  53    return 0;
  54 }
  55
  56 static int
  57 _parse_defined(struct sl_pp_context *context,
  58                struct sl_pp_token_buffer *buffer,
  59                struct sl_pp_process_state *state)
  60 {
  61    struct sl_pp_token_info input;
  62    int parens = 0;
  63    int defined;
  64    struct sl_pp_token_info result;
  65
  66    if (sl_pp_token_buffer_skip_white(buffer, &input)) {
  67       return -1;
  68    }
  69
  70    if (input.token == SL_PP_LPAREN) {
  71       if (sl_pp_token_buffer_skip_white(buffer, &input)) {
  72          return -1;
  73       }
  74       parens = 1;
  75    }
  76
  77    if (input.token != SL_PP_IDENTIFIER) {
  78       strcpy(context->error_msg, "expected an identifier");
  79       return -1;
  80    }
  81
  82    defined = _macro_is_defined(context, input.data.identifier);
  83
  84    if (parens) {
  85       if (sl_pp_token_buffer_skip_white(buffer, &input)) {
  86          return -1;
  87       }
  88       if (input.token != SL_PP_RPAREN) {
  89          strcpy(context->error_msg, "expected `)'");
  90          return -1;
  91       }
  92    }
  93
  94    result.token = SL_PP_UINT;
  95    result.data._uint = (defined ? context->dict._1 : context->dict._0);
  96
  97    if (sl_pp_process_out(state, &result)) {
  98       strcpy(context->error_msg, "out of memory");
  99       return -1;
 100    }
 101
 102    return 0;
 103 }
 104
 105 static unsigned int
 106 _evaluate_if_stack(struct sl_pp_context *context)
 107 {
 108    unsigned int i;
 109
 110    for (i = context->if_ptr; i < SL_PP_MAX_IF_NESTING; i++) {
 111       if (!context->if_stack[i].u.condition) {
 112          return 0;
 113       }
 114    }
 115    return 1;
 116 }
 117
 118 static int
 119 _parse_if(struct sl_pp_context *context,
 120           struct sl_pp_token_buffer *buffer)
 121 {
 122    struct sl_pp_process_state state;
 123    int found_end = 0;
 124    struct sl_pp_token_info eof;
 125    int result;
 126
 127    if (!context->if_ptr) {
 128       strcpy(context->error_msg, "`#if' nesting too deep");
 129       return -1;
 130    }
 131
 132    memset(&state, 0, sizeof(state));
 133    while (!found_end) {
 134       struct sl_pp_token_info input;
 135
 136       sl_pp_token_buffer_get(buffer, &input);
 137       switch (input.token) {
 138       case SL_PP_WHITESPACE:
 139          break;
 140
 141       case SL_PP_IDENTIFIER:
 142          if (input.data.identifier == context->dict.defined) {
 143             if (_parse_defined(context, buffer, &state)) {
 144                free(state.out);
 145                return -1;
 146             }
 147          } else {
 148             sl_pp_token_buffer_unget(buffer, &input);
 149             if (sl_pp_macro_expand(context, buffer, NULL, &state, sl_pp_macro_expand_unknown_to_0)) {
 150                free(state.out);
 151                return -1;
 152             }
 153          }
 154          break;
 155
 156       case SL_PP_NEWLINE:
 157       case SL_PP_EOF:
 158          found_end = 1;
 159          break;
 160
 161       default:
 162          if (sl_pp_process_out(&state, &input)) {
 163             strcpy(context->error_msg, "out of memory");
 164             free(state.out);
 165             return -1;
 166          }
 167       }
 168    }
 169
 170    eof.token = SL_PP_EOF;
 171    if (sl_pp_process_out(&state, &eof)) {
 172       strcpy(context->error_msg, "out of memory");
 173       free(state.out);
 174       return -1;
 175    }
 176
 177    if (sl_pp_execute_expression(context, state.out, &result)) {
 178       free(state.out);
 179       return -1;
 180    }
 181
 182    free(state.out);
 183
 184    context->if_ptr--;
 185    context->if_stack[context->if_ptr].value = 0;
 186    context->if_stack[context->if_ptr].u.condition = result ? 1 : 0;
 187    context->if_value = _evaluate_if_stack(context);
 188
 189    return 0;
 190 }
 191
 192 static int
 193 _parse_else(struct sl_pp_context *context)
 194 {
 195    union sl_pp_if_state *state = &context->if_stack[context->if_ptr];
 196
 197    if (context->if_ptr == SL_PP_MAX_IF_NESTING) {
 198       strcpy(context->error_msg, "no matching `#if'");
 199       return -1;
 200    }
 201
 202    if (state->u.went_thru_else) {
 203       strcpy(context->error_msg, "no matching `#if'");
 204       return -1;
 205    }
 206
 207    /* Once we had a true condition, the subsequent #elifs should always be false. */
 208    state->u.had_true_cond |= state->u.condition;
 209
 210    /* Update current condition value and mark that we are in the #else block. */
 211    state->u.condition = !(state->u.had_true_cond | state->u.condition);
 212    state->u.went_thru_else = 1;
 213    context->if_value = _evaluate_if_stack(context);
 214
 215    return 0;
 216 }
 217
 218 int
 219 sl_pp_process_if(struct sl_pp_context *context,
 220                  struct sl_pp_token_buffer *buffer)
 221 {
 222    return _parse_if(context, buffer);
 223 }
 224
 225 int
 226 sl_pp_process_ifdef(struct sl_pp_context *context,
 227                     const struct sl_pp_token_info *input,
 228                     unsigned int first,
 229                     unsigned int last)
 230 {
 231    unsigned int i;
 232
 233    if (!context->if_ptr) {
 234       strcpy(context->error_msg, "`#if' nesting too deep");
 235       return -1;
 236    }
 237
 238    for (i = first; i < last; i++) {
 239       switch (input[i].token) {
 240       case SL_PP_IDENTIFIER:
 241          context->if_ptr--;
 242          context->if_stack[context->if_ptr].value = 0;
 243          context->if_stack[context->if_ptr].u.condition = _macro_is_defined(context, input[i].data.identifier);
 244          context->if_value = _evaluate_if_stack(context);
 245          return 0;
 246
 247       case SL_PP_WHITESPACE:
 248          break;
 249
 250       default:
 251          strcpy(context->error_msg, "expected an identifier");
 252          return -1;
 253       }
 254    }
 255
 256    strcpy(context->error_msg, "expected an identifier");
 257    return -1;
 258 }
 259
 260 int
 261 sl_pp_process_ifndef(struct sl_pp_context *context,
 262                      const struct sl_pp_token_info *input,
 263                      unsigned int first,
 264                      unsigned int last)
 265 {
 266    unsigned int i;
 267
 268    if (!context->if_ptr) {
 269       strcpy(context->error_msg, "`#if' nesting too deep");
 270       return -1;
 271    }
 272
 273    for (i = first; i < last; i++) {
 274       switch (input[i].token) {
 275       case SL_PP_IDENTIFIER:
 276          context->if_ptr--;
 277          context->if_stack[context->if_ptr].value = 0;
 278          context->if_stack[context->if_ptr].u.condition = !_macro_is_defined(context, input[i].data.identifier);
 279          context->if_value = _evaluate_if_stack(context);
 280          return 0;
 281
 282       case SL_PP_WHITESPACE:
 283          break;
 284
 285       default:
 286          strcpy(context->error_msg, "expected an identifier");
 287          return -1;
 288       }
 289    }
 290
 291    strcpy(context->error_msg, "expected an identifier");
 292    return -1;
 293 }
 294
 295 int
 296 sl_pp_process_elif(struct sl_pp_context *context,
 297                    struct sl_pp_token_buffer *buffer)
 298 {
 299    if (_parse_else(context)) {
 300       return -1;
 301    }
 302
 303    if (context->if_stack[context->if_ptr].u.condition) {
 304       context->if_ptr++;
 305       if (_parse_if(context, buffer)) {
 306          return -1;
 307       }
 308    }
 309
 310    /* We are still in the #if block. */
 311    context->if_stack[context->if_ptr].u.went_thru_else = 0;
 312
 313    return 0;
 314 }
 315
 316 int
 317 sl_pp_process_else(struct sl_pp_context *context,
 318                    const struct sl_pp_token_info *input,
 319                    unsigned int first,
 320                    unsigned int last)
 321 {
 322    return _parse_else(context);
 323 }
 324
 325 int
 326 sl_pp_process_endif(struct sl_pp_context *context,
 327                     const struct sl_pp_token_info *input,
 328                     unsigned int first,
 329                     unsigned int last)
 330 {
 331    if (context->if_ptr == SL_PP_MAX_IF_NESTING) {
 332       strcpy(context->error_msg, "no matching `#if'");
 333       return -1;
 334    }
 335
 336    context->if_ptr++;
 337    context->if_value = _evaluate_if_stack(context);
 338
 339    return 0;
 340 }