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/*************************************************************************
* Copyright (C) 2010 Tavian Barnes <tavianator@gmail.com> *
* *
* This file is part of Dimension. *
* *
* Dimension is free software; you can redistribute it and/or modify it *
* under the terms of the GNU General Public License as published by the *
* Free Software Foundation; either version 3 of the License, or (at *
* your option) any later version. *
* *
* Dimension is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
*************************************************************************/
#include "tokenize.h"
#include "directives.h"
#include "utility.h"
typedef struct dmnsn_buffered_token {
int type;
dmnsn_parse_item lval;
dmnsn_parse_location lloc;
} dmnsn_buffered_token;
typedef struct dmnsn_yylex_extra {
int type;
/* Indicate that the first token should be returned as-is */
#define DMNSN_T_LEX_VERBATIM DMNSN_T_EOF
dmnsn_array *buffered;
unsigned int i;
struct dmnsn_yylex_extra *prev;
} dmnsn_yylex_extra;
dmnsn_yylex_extra *
dmnsn_new_yylex_extra(int type)
{
dmnsn_yylex_extra *extra = malloc(sizeof(dmnsn_yylex_extra));
if (!extra) {
dmnsn_error(DMNSN_SEVERITY_HIGH, "Failed to allocate token buffer.");
}
extra->type = type;
extra->buffered = dmnsn_new_array(sizeof(dmnsn_buffered_token));
extra->i = 0;
extra->prev = NULL;
return extra;
}
void
dmnsn_delete_yylex_extra(dmnsn_yylex_extra *extra)
{
if (extra) {
dmnsn_delete_array(extra->buffered);
free(extra);
}
}
int dmnsn_yylex_impl(dmnsn_parse_item *lvalp, dmnsn_parse_location *llocp,
const char *filename, void *yyscanner);
int dmnsn_ld_yyparse(const char *filename, void *yyscanner,
dmnsn_symbol_table *symtable);
int
dmnsn_yylex(dmnsn_parse_item *lvalp, dmnsn_parse_location *llocp,
const char *filename, dmnsn_symbol_table *symtable, void *yyscanner)
{
/*
* So... this is kind of ugly. POV-Ray's language directives are not parsable
* by reasonable bison grammar, since some require skipping arbitrary amounts
* of tokens, or repeatedly parsing tokens. Instead, they are implemented
* transparently by the lexer. The lexing function calls a separate parser
* to handle language directives as they arrise, and returns only non-
* directive tokens.
*
* Ideally we'd use a push parser for the language directives, but bison
* doesn't support GLR push parsers.
*/
dmnsn_yylex_extra *extra = dmnsn_yyget_extra(yyscanner);
int token;
while (1) {
if (extra) {
/* We are returning buffered tokens */
dmnsn_buffered_token buffered;
if (extra->i < dmnsn_array_size(extra->buffered)) {
dmnsn_array_get(extra->buffered, extra->i, &buffered);
token = buffered.type;
*lvalp = buffered.lval;
*llocp = buffered.lloc;
++extra->i;
if (extra->type == DMNSN_T_LEX_VERBATIM && extra->i == 1) {
/* Don't reprocess the first token in some situations */
return token;
}
} else {
dmnsn_yyset_extra(extra->prev, yyscanner);
dmnsn_delete_yylex_extra(extra);
extra = dmnsn_yyget_extra(yyscanner);
continue;
}
} else {
token = dmnsn_yylex_impl(lvalp, llocp, filename, yyscanner);
}
switch (token) {
case DMNSN_T_DECLARE:
case DMNSN_T_LOCAL:
{
dmnsn_yylex_extra *ex = dmnsn_new_yylex_extra(DMNSN_T_LEX_VERBATIM);
ex->prev = extra;
/* Buffer the current token */
dmnsn_buffered_token buffered = {
.type = token,
.lval = *lvalp,
.lloc = *llocp
};
dmnsn_array_push(ex->buffered, &buffered);
/* Grab all the tokens belonging to the #declare/#local */
int bracelevel = -1;
while (1) {
/* Recursive call */
buffered.type = dmnsn_yylex(&buffered.lval, &buffered.lloc,
filename, symtable, yyscanner);
if (buffered.type == DMNSN_T_EOF) {
dmnsn_diagnostic(filename, buffered.lloc.first_line,
buffered.lloc.first_column,
"unexpected end-of-file");
dmnsn_delete_yylex_extra(ex);
return DMNSN_T_LEX_ERROR;
} else if (buffered.type == DMNSN_T_LEX_ERROR) {
dmnsn_delete_yylex_extra(ex);
return DMNSN_T_LEX_ERROR;
}
dmnsn_array_push(ex->buffered, &buffered);
if (buffered.type == DMNSN_T_LBRACE) {
if (bracelevel < 0)
bracelevel = 1;
else
++bracelevel;
} else if (buffered.type == DMNSN_T_RBRACE) {
--bracelevel;
if (bracelevel == 0) {
break;
}
} else if (buffered.type == DMNSN_T_SEMICOLON) {
break;
}
}
/* Fake EOF */
buffered.type = DMNSN_T_EOF;
dmnsn_array_push(ex->buffered, &buffered);
dmnsn_yyset_extra(ex, yyscanner);
if (dmnsn_ld_yyparse(filename, yyscanner, symtable) != 0) {
dmnsn_yyset_extra(ex->prev, yyscanner);
dmnsn_delete_yylex_extra(ex);
return DMNSN_T_LEX_ERROR;
}
/* Restore the previous extra pointer */
dmnsn_yyset_extra(ex->prev, yyscanner);
dmnsn_delete_yylex_extra(ex);
break;
}
case DMNSN_T_UNDEF:
{
dmnsn_yylex_extra *ex = dmnsn_new_yylex_extra(DMNSN_T_LEX_VERBATIM);
ex->prev = extra;
/* Buffer the current token */
dmnsn_buffered_token buffered = {
.type = token,
.lval = *lvalp,
.lloc = *llocp
};
dmnsn_array_push(ex->buffered, &buffered);
/* Recursive call */
buffered.type = dmnsn_yylex(&buffered.lval, &buffered.lloc,
filename, symtable, yyscanner);
if (buffered.type == DMNSN_T_EOF) {
dmnsn_diagnostic(filename, buffered.lloc.first_line,
buffered.lloc.first_column,
"unexpected end-of-file");
dmnsn_delete_yylex_extra(ex);
return DMNSN_T_LEX_ERROR;
} else if (buffered.type == DMNSN_T_LEX_ERROR) {
dmnsn_delete_yylex_extra(ex);
return DMNSN_T_LEX_ERROR;
}
/* Buffer the next token */
dmnsn_array_push(ex->buffered, &buffered);
/* Fake EOF */
buffered.type = DMNSN_T_EOF;
dmnsn_array_push(ex->buffered, &buffered);
dmnsn_yyset_extra(ex, yyscanner);
if (dmnsn_ld_yyparse(filename, yyscanner, symtable) != 0) {
dmnsn_yyset_extra(ex->prev, yyscanner);
dmnsn_delete_yylex_extra(ex);
return DMNSN_T_LEX_ERROR;
}
/* Restore the previous extra pointer */
dmnsn_yyset_extra(ex->prev, yyscanner);
dmnsn_delete_yylex_extra(ex);
break;
}
default:
return token;
}
}
}
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