src/glsl/pp/sl_pp_token_util.h

   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
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  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
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  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #ifndef SL_PP_TOKEN_UTIL_H
  29 #define SL_PP_TOKEN_UTIL_H
  30
  31 #include <assert.h>
  32 #include <stdlib.h>
  33 #include "sl_pp_token.h"
  34
  35
  36 struct sl_pp_context;
  37
  38 /*
  39  * A token buffer allows one to get and unget a token
  40  * from a preprocessor context.
  41  */
  42 struct sl_pp_token_buffer {
  43    struct sl_pp_context *context;
  44    unsigned int size;
  45    unsigned int capacity;
  46    struct sl_pp_token_info *tokens;
  47 };
  48
  49 static int
  50 sl_pp_token_buffer_init(struct sl_pp_token_buffer *buffer,
  51                         struct sl_pp_context *context)
  52 {
  53    buffer->context = context;
  54    buffer->size = 0;
  55    buffer->capacity = 64;
  56    buffer->tokens = malloc(buffer->capacity * sizeof(struct sl_pp_token_info));
  57    if (!buffer->tokens) {
  58       return -1;
  59    }
  60    return 0;
  61 }
  62
  63 static void
  64 sl_pp_token_buffer_destroy(struct sl_pp_token_buffer *buffer)
  65 {
  66    free(buffer->tokens);
  67 }
  68
  69 static int
  70 sl_pp_token_buffer_get(struct sl_pp_token_buffer *buffer,
  71                        struct sl_pp_token_info *out)
  72 {
  73    /* Pop from stack first if not empty. */
  74    if (buffer->size) {
  75       *out = buffer->tokens[--buffer->size];
  76       return 0;
  77    }
  78
  79    assert(buffer->context);
  80    return sl_pp_token_get(buffer->context, out);
  81 }
  82
  83 static void
  84 sl_pp_token_buffer_unget(struct sl_pp_token_buffer *buffer,
  85                          const struct sl_pp_token_info *in)
  86 {
  87    /* Resize if needed. */
  88    if (buffer->size == buffer->capacity) {
  89       buffer->capacity += 64;
  90       buffer->tokens = realloc(buffer->tokens,
  91                                buffer->capacity * sizeof(struct sl_pp_token_info));
  92       assert(buffer->tokens);
  93    }
  94
  95    /* Push token on stack. */
  96    buffer->tokens[buffer->size++] = *in;
  97 }
  98
  99 static int
 100 sl_pp_token_buffer_skip_white(struct sl_pp_token_buffer *buffer,
 101                               struct sl_pp_token_info *out)
 102 {
 103    if (sl_pp_token_buffer_get(buffer, out)) {
 104       return -1;
 105    }
 106
 107    while (out->token == SL_PP_WHITESPACE) {
 108       if (sl_pp_token_buffer_get(buffer, out)) {
 109          return -1;
 110       }
 111    }
 112
 113    return 0;
 114 }
 115
 116
 117 /*
 118  * A token peek allows one to get a number of tokens from a buffer
 119  * and then either commit the operation or abort it,
 120  * effectively ungetting the peeked tokens.
 121  */
 122 struct sl_pp_token_peek {
 123    struct sl_pp_token_buffer *buffer;
 124    unsigned int size;
 125    unsigned int capacity;
 126    struct sl_pp_token_info *tokens;
 127 };
 128
 129 static int
 130 sl_pp_token_peek_init(struct sl_pp_token_peek *peek,
 131                       struct sl_pp_token_buffer *buffer)
 132 {
 133    peek->buffer = buffer;
 134    peek->size = 0;
 135    peek->capacity = 64;
 136    peek->tokens = malloc(peek->capacity * sizeof(struct sl_pp_token_info));
 137    if (!peek->tokens) {
 138       return -1;
 139    }
 140    return 0;
 141 }
 142
 143 static void
 144 sl_pp_token_peek_destroy(struct sl_pp_token_peek *peek)
 145 {
 146    /* Abort. */
 147    while (peek->size) {
 148       sl_pp_token_buffer_unget(peek->buffer, &peek->tokens[--peek->size]);
 149    }
 150    free(peek->tokens);
 151 }
 152
 153 static int
 154 sl_pp_token_peek_get(struct sl_pp_token_peek *peek,
 155                      struct sl_pp_token_info *out)
 156 {
 157    /* Get token from buffer. */
 158    if (sl_pp_token_buffer_get(peek->buffer, out)) {
 159       return -1;
 160    }
 161
 162    /* Save it. */
 163    if (peek->size == peek->capacity) {
 164       peek->capacity += 64;
 165       peek->tokens = realloc(peek->tokens,
 166                              peek->capacity * sizeof(struct sl_pp_token_info));
 167       assert(peek->tokens);
 168    }
 169    peek->tokens[peek->size++] = *out;
 170    return 0;
 171 }
 172
 173 static void
 174 sl_pp_token_peek_commit(struct sl_pp_token_peek *peek)
 175 {
 176    peek->size = 0;
 177 }
 178
 179 static int
 180 sl_pp_token_peek_to_buffer(const struct sl_pp_token_peek *peek,
 181                            struct sl_pp_token_buffer *buffer)
 182 {
 183    unsigned int i;
 184
 185    if (sl_pp_token_buffer_init(buffer, NULL)) {
 186       return -1;
 187    }
 188    for (i = peek->size; i > 0; i--) {
 189       sl_pp_token_buffer_unget(buffer, &peek->tokens[i - 1]);
 190    }
 191    return 0;
 192 }
 193
 194 static int
 195 sl_pp_token_peek_skip_white(struct sl_pp_token_peek *peek,
 196                             struct sl_pp_token_info *out)
 197 {
 198    if (sl_pp_token_peek_get(peek, out)) {
 199       return -1;
 200    }
 201
 202    while (out->token == SL_PP_WHITESPACE) {
 203       if (sl_pp_token_peek_get(peek, out)) {
 204          return -1;
 205       }
 206    }
 207
 208    return 0;
 209 }
 210
 211 #endif /* SL_PP_TOKEN_UTIL_H */