C++ eat_opt_white函数代码示例

/* parses a 4-touple of the form {x, y, z, w}
 * where x, y, z, w are numbers */
static boolean parse_immediate_data(struct translate_ctx *ctx,
                                    float *values)
{
   unsigned i;

   eat_opt_white( &ctx->cur );
   if (*ctx->cur != '{') {
      report_error( ctx, "Expected `{'" );
      return FALSE;
   }
   ctx->cur++;
   for (i = 0; i < 4; i++) {
      eat_opt_white( &ctx->cur );
      if (i > 0) {
         if (*ctx->cur != ',') {
            report_error( ctx, "Expected `,'" );
            return FALSE;
         }
         ctx->cur++;
         eat_opt_white( &ctx->cur );
      }
      if (!parse_float( &ctx->cur, &values[i] )) {
         report_error( ctx, "Expected literal floating point" );
         return FALSE;
      }
   }
   eat_opt_white( &ctx->cur );
   if (*ctx->cur != '}') {
      report_error( ctx, "Expected `}'" );
      return FALSE;
   }
   ctx->cur++;

   return TRUE;
}

/* parses a 4-touple of the form {x, y, z, w}
 * where x, y, z, w are numbers */
static boolean parse_immediate_data(struct translate_ctx *ctx, unsigned type,
                                    union tgsi_immediate_data *values)
{
   unsigned i;
   int ret;

   eat_opt_white( &ctx->cur );
   if (*ctx->cur != '{') {
      report_error( ctx, "Expected `{'" );
      return FALSE;
   }
   ctx->cur++;
   for (i = 0; i < 4; i++) {
      eat_opt_white( &ctx->cur );
      if (i > 0) {
         if (*ctx->cur != ',') {
            report_error( ctx, "Expected `,'" );
            return FALSE;
         }
         ctx->cur++;
         eat_opt_white( &ctx->cur );
      }

      switch (type) {
      case TGSI_IMM_FLOAT64:
         ret = parse_double(&ctx->cur, &values[i].Uint, &values[i+1].Uint);
         i++;
         break;
      case TGSI_IMM_FLOAT32:
         ret = parse_float(&ctx->cur, &values[i].Float);
         break;
      case TGSI_IMM_UINT32:
         ret = parse_uint(&ctx->cur, &values[i].Uint);
         break;
      case TGSI_IMM_INT32:
         ret = parse_int(&ctx->cur, &values[i].Int);
         break;
      default:
         assert(0);
         ret = FALSE;
         break;
      }

      if (!ret) {
         report_error( ctx, "Expected immediate constant" );
         return FALSE;
      }
   }
   eat_opt_white( &ctx->cur );
   if (*ctx->cur != '}') {
      report_error( ctx, "Expected `}'" );
      return FALSE;
   }
   ctx->cur++;

   return TRUE;
}

static boolean
parse_register_dcl_bracket(
   struct translate_ctx *ctx,
   struct parsed_dcl_bracket *bracket)
{
   uint uindex;
   memset(bracket, 0, sizeof(struct parsed_dcl_bracket));

   eat_opt_white( &ctx->cur );

   if (!parse_uint( &ctx->cur, &uindex )) {
      /* it can be an empty bracket [] which means its range
       * is from 0 to some implied size */
      if (ctx->cur[0] == ']' && ctx->implied_array_size != 0) {
         bracket->first = 0;
         bracket->last = ctx->implied_array_size - 1;
         goto cleanup;
      }
      report_error( ctx, "Expected literal unsigned integer" );
      return FALSE;
   }
   bracket->first = uindex;

   eat_opt_white( &ctx->cur );

   if (ctx->cur[0] == '.' && ctx->cur[1] == '.') {
      uint uindex;

      ctx->cur += 2;
      eat_opt_white( &ctx->cur );
      if (!parse_uint( &ctx->cur, &uindex )) {
         report_error( ctx, "Expected literal integer" );
         return FALSE;
      }
      bracket->last = (int) uindex;
      eat_opt_white( &ctx->cur );
   }
   else {
      bracket->last = bracket->first;
   }

cleanup:
   if (*ctx->cur != ']') {
      report_error( ctx, "Expected `]' or `..'" );
      return FALSE;
   }
   ctx->cur++;
   return TRUE;
}

/* Eat one or more whitespaces.
 * Return TRUE if at least one whitespace eaten.
 */
static boolean eat_white( const char **pcur )
{
   const char *cur = *pcur;

   eat_opt_white( pcur );
   return *pcur > cur;
}

static boolean
parse_opt_writemask(
   struct translate_ctx *ctx,
   uint *writemask )
{
   const char *cur;

   cur = ctx->cur;
   eat_opt_white( &cur );
   if (*cur == '.') {
      cur++;
      *writemask = TGSI_WRITEMASK_NONE;
      eat_opt_white( &cur );
      if (uprcase( *cur ) == 'X') {
         cur++;
         *writemask |= TGSI_WRITEMASK_X;
      }
      if (uprcase( *cur ) == 'Y') {
         cur++;
         *writemask |= TGSI_WRITEMASK_Y;
      }
      if (uprcase( *cur ) == 'Z') {
         cur++;
         *writemask |= TGSI_WRITEMASK_Z;
      }
      if (uprcase( *cur ) == 'W') {
         cur++;
         *writemask |= TGSI_WRITEMASK_W;
      }

      if (*writemask == TGSI_WRITEMASK_NONE) {
         report_error( ctx, "Writemask expected" );
         return FALSE;
      }

      ctx->cur = cur;
   }
   else {
      *writemask = TGSI_WRITEMASK_XYZW;
   }
   return TRUE;
}

static boolean parse_label( struct translate_ctx *ctx, uint *val )
{
   const char *cur = ctx->cur;

   if (parse_uint( &cur, val )) {
      eat_opt_white( &cur );
      if (*cur == ':') {
         cur++;
         ctx->cur = cur;
         return TRUE;
      }
   }
   return FALSE;
}

static boolean
parse_optional_swizzle(
   struct translate_ctx *ctx,
   uint *swizzle,
   boolean *parsed_swizzle,
   int components)
{
   const char *cur = ctx->cur;

   *parsed_swizzle = FALSE;

   eat_opt_white( &cur );
   if (*cur == '.') {
      uint i;

      cur++;
      eat_opt_white( &cur );
      for (i = 0; i < components; i++) {
         if (uprcase( *cur ) == 'X')
            swizzle[i] = TGSI_SWIZZLE_X;
         else if (uprcase( *cur ) == 'Y')
            swizzle[i] = TGSI_SWIZZLE_Y;
         else if (uprcase( *cur ) == 'Z')
            swizzle[i] = TGSI_SWIZZLE_Z;
         else if (uprcase( *cur ) == 'W')
            swizzle[i] = TGSI_SWIZZLE_W;
         else {
	    report_error( ctx, "Expected register swizzle component `x', `y', `z' or `w'" );
	    return FALSE;
         }
         cur++;
      }
      *parsed_swizzle = TRUE;
      ctx->cur = cur;
   }
   return TRUE;
}

static boolean
parse_dst_operand(
   struct translate_ctx *ctx,
   struct tgsi_full_dst_register *dst )
{
   uint file;
   uint writemask;
   const char *cur;
   struct parsed_bracket bracket[2];
   int parsed_opt_brackets;

   if (!parse_register_dst( ctx, &file, &bracket[0] ))
      return FALSE;
   if (!parse_opt_register_src_bracket(ctx, &bracket[1], &parsed_opt_brackets))
      return FALSE;

   cur = ctx->cur;
   eat_opt_white( &cur );

   if (!parse_opt_writemask( ctx, &writemask ))
      return FALSE;

   dst->Register.File = file;
   if (parsed_opt_brackets) {
      dst->Register.Dimension = 1;
      dst->Dimension.Indirect = 0;
      dst->Dimension.Dimension = 0;
      dst->Dimension.Index = bracket[0].index;

      if (bracket[0].ind_file != TGSI_FILE_NULL) {
         dst->Dimension.Indirect = 1;
         dst->DimIndirect.File = bracket[0].ind_file;
         dst->DimIndirect.Index = bracket[0].ind_index;
         dst->DimIndirect.Swizzle = bracket[0].ind_comp;
         dst->DimIndirect.ArrayID = bracket[0].ind_array;
      }
      bracket[0] = bracket[1];
   }
   dst->Register.Index = bracket[0].index;
   dst->Register.WriteMask = writemask;
   if (bracket[0].ind_file != TGSI_FILE_NULL) {
      dst->Register.Indirect = 1;
      dst->Indirect.File = bracket[0].ind_file;
      dst->Indirect.Index = bracket[0].ind_index;
      dst->Indirect.Swizzle = bracket[0].ind_comp;
      dst->Indirect.ArrayID = bracket[0].ind_array;
   }
   return TRUE;
}

/* Parse simple 1d register operand.
 *    <register_dst> ::= <register_file_bracket_index> `]'
 */
static boolean
parse_register_1d(struct translate_ctx *ctx,
                  uint *file,
                  int *index )
{
   if (!parse_register_file_bracket_index( ctx, file, index ))
      return FALSE;
   eat_opt_white( &ctx->cur );
   if (*ctx->cur != ']') {
      report_error( ctx, "Expected `]'" );
      return FALSE;
   }
   ctx->cur++;
   return TRUE;
}

/* Parse register declaration.
 *    <register_dcl> ::= <register_file_bracket_index> `]' |
 *                       <register_file_bracket_index> `..' <index> `]'
 */
static boolean
parse_register_dcl(
   struct translate_ctx *ctx,
   uint *file,
   struct parsed_dcl_bracket *brackets,
   int *num_brackets)
{
   const char *cur;

   *num_brackets = 0;

   if (!parse_register_file_bracket( ctx, file ))
      return FALSE;
   if (!parse_register_dcl_bracket( ctx, &brackets[0] ))
      return FALSE;

   *num_brackets = 1;

   cur = ctx->cur;
   eat_opt_white( &cur );

   if (cur[0] == '[') {
      bool is_in = *file == TGSI_FILE_INPUT;
      bool is_out = *file == TGSI_FILE_OUTPUT;

      ++cur;
      ctx->cur = cur;
      if (!parse_register_dcl_bracket( ctx, &brackets[1] ))
         return FALSE;
      /* for geometry shader we don't really care about
       * the first brackets it's always the size of the
       * input primitive. so we want to declare just
       * the index relevant to the semantics which is in
       * the second bracket */

      /* tessellation has similar constraints to geometry shader */
      if ((ctx->processor == TGSI_PROCESSOR_GEOMETRY && is_in) ||
          (ctx->processor == TGSI_PROCESSOR_TESS_EVAL && is_in) ||
          (ctx->processor == TGSI_PROCESSOR_TESS_CTRL && (is_in || is_out))) {
         brackets[0] = brackets[1];
         *num_brackets = 1;
      } else {
         *num_brackets = 2;
      }
   }

   return TRUE;
}

/* <register_file_bracket> ::= <file> `['
 */
static boolean
parse_register_file_bracket(
   struct translate_ctx *ctx,
   uint *file )
{
   if (!parse_file( &ctx->cur, file )) {
      report_error( ctx, "Unknown register file" );
      return FALSE;
   }
   eat_opt_white( &ctx->cur );
   if (*ctx->cur != '[') {
      report_error( ctx, "Expected `['" );
      return FALSE;
   }
   ctx->cur++;
   return TRUE;
}

/* <register_file_bracket_index> ::= <register_file_bracket> <uint>
 */
static boolean
parse_register_file_bracket_index(
   struct translate_ctx *ctx,
   uint *file,
   int *index )
{
   uint uindex;

   if (!parse_register_file_bracket( ctx, file ))
      return FALSE;
   eat_opt_white( &ctx->cur );
   if (!parse_uint( &ctx->cur, &uindex )) {
      report_error( ctx, "Expected literal unsigned integer" );
      return FALSE;
   }
   *index = (int) uindex;
   return TRUE;
}

static boolean translate( struct translate_ctx *ctx )
{
   eat_opt_white( &ctx->cur );
   if (!parse_header( ctx ))
      return FALSE;

   if (ctx->processor == TGSI_PROCESSOR_TESS_CTRL ||
       ctx->processor == TGSI_PROCESSOR_TESS_EVAL)
       ctx->implied_array_size = 32;

   while (*ctx->cur != '\0') {
      uint label_val = 0;
      if (!eat_white( &ctx->cur )) {
         report_error( ctx, "Syntax error" );
         return FALSE;
      }

      if (*ctx->cur == '\0')
         break;
      if (parse_label( ctx, &label_val )) {
         if (!parse_instruction( ctx, TRUE ))
            return FALSE;
      }
      else if (str_match_nocase_whole( &ctx->cur, "DCL" )) {
         if (!parse_declaration( ctx ))
            return FALSE;
      }
      else if (str_match_nocase_whole( &ctx->cur, "IMM" )) {
         if (!parse_immediate( ctx ))
            return FALSE;
      }
      else if (str_match_nocase_whole( &ctx->cur, "PROPERTY" )) {
         if (!parse_property( ctx ))
            return FALSE;
      }
      else if (!parse_instruction( ctx, FALSE )) {
         return FALSE;
      }
   }

   return TRUE;
}

static boolean translate( struct translate_ctx *ctx )
{
   eat_opt_white( &ctx->cur );
   if (!parse_header( ctx ))
      return FALSE;

   while (*ctx->cur != '\0') {
      uint label_val = 0;
      if (!eat_white( &ctx->cur )) {
         report_error( ctx, "Syntax error" );
         return FALSE;
      }

      if (*ctx->cur == '\0')
         break;
      if (parse_label( ctx, &label_val )) {
         if (!parse_instruction( ctx, TRUE ))
            return FALSE;
      }
      else if (str_match_no_case( &ctx->cur, "DCL" )) {
         if (!parse_declaration( ctx ))
            return FALSE;
      }
      else if (str_match_no_case( &ctx->cur, "IMM" )) {
         if (!parse_immediate( ctx ))
            return FALSE;
      }
      else if (str_match_no_case( &ctx->cur, "PROPERTY" )) {
         if (!parse_property( ctx ))
            return FALSE;
      }
      else if (!parse_instruction( ctx, FALSE )) {
         return FALSE;
      }
   }

   return TRUE;
}

static boolean
parse_opt_register_src_bracket(
   struct translate_ctx *ctx,
   struct parsed_bracket *brackets,
   int *parsed_brackets)
{
   const char *cur = ctx->cur;

   *parsed_brackets = 0;

   eat_opt_white( &cur );
   if (cur[0] == '[') {
      ++cur;
      ctx->cur = cur;

      if (!parse_register_bracket(ctx, brackets))
         return FALSE;

      *parsed_brackets = 1;
   }

   return TRUE;
}