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elinks/src/dom/scanner.c

180 lines
4.4 KiB
C

/* A pretty generic scanner */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include "elinks.h"
#include "dom/scanner.h"
#include "dom/string.h"
#include "util/error.h"
int
map_dom_scanner_string(struct dom_scanner *scanner,
unsigned char *ident, unsigned char *end, int base_type)
{
const struct dom_scanner_string_mapping *mappings = scanner->info->mappings;
struct dom_string name = INIT_DOM_STRING(ident, end - ident);
for (; is_dom_string_set(&mappings->name); mappings++) {
if (mappings->base_type == base_type
&& !dom_string_casecmp(&mappings->name, &name))
return mappings->type;
}
return base_type;
}
struct dom_scanner_token *
skip_dom_scanner_tokens(struct dom_scanner *scanner, int skipto, int precedence)
{
struct dom_scanner_token *token = get_dom_scanner_token(scanner);
/* Skip tokens while handling some basic precedens of special chars
* so we don't skip to long. */
while (token) {
if (token->type == skipto
|| token->precedence > precedence)
break;
token = get_next_dom_scanner_token(scanner);
}
return (token && token->type == skipto)
? get_next_dom_scanner_token(scanner) : NULL;
}
#ifdef DEBUG_SCANNER
void
dump_dom_scanner(struct dom_scanner *scanner)
{
unsigned char buffer[MAX_STR_LEN];
struct dom_scanner_token *token = scanner->current;
struct dom_scanner_token *table_end = scanner->table + scanner->tokens;
unsigned char *srcpos = token->string, *bufpos = buffer;
int src_lookahead = 50;
int token_lookahead = 4;
int srclen;
if (!dom_scanner_has_tokens(scanner)) return;
memset(buffer, 0, MAX_STR_LEN);
for (; token_lookahead > 0 && token < table_end; token++, token_lookahead--) {
int buflen = MAX_STR_LEN - (bufpos - buffer);
int added = snprintf(bufpos, buflen, "[%.*s] ", token->length, token->string);
bufpos += added;
}
if (scanner->tokens > token_lookahead) {
memcpy(bufpos, "... ", 4);
bufpos += 4;
}
srclen = strlen(srcpos);
int_upper_bound(&src_lookahead, srclen);
*bufpos++ = '[';
/* Compress the lookahead string */
for (; src_lookahead > 0; src_lookahead--, srcpos++, bufpos++) {
if (*srcpos == '\n' || *srcpos == '\r' || *srcpos == '\t') {
*bufpos++ = '\\';
*bufpos = *srcpos == '\n' ? 'n'
: (*srcpos == '\r' ? 'r' : 't');
} else {
*bufpos = *srcpos;
}
}
if (srclen > src_lookahead)
memcpy(bufpos, "...]", 4);
else
memcpy(bufpos, "]", 2);
errfile = scanner->file, errline = scanner->line;
elinks_wdebug("%s", buffer);
}
struct dom_scanner_token *
get_dom_scanner_token_debug(struct dom_scanner *scanner)
{
if (!dom_scanner_has_tokens(scanner)) return NULL;
dump_dom_scanner(scanner);
/* Make sure we do not return invalid tokens */
assert(!dom_scanner_has_tokens(scanner)
|| scanner->current->type != 0);
return get_dom_scanner_token(scanner);
}
#endif
/* Initializers */
static inline void
init_dom_scanner_info(struct dom_scanner_info *scanner_info)
{
const struct dom_scan_table_info *info = scanner_info->scan_table_info;
int *scan_table = scanner_info->scan_table;
int i;
if (!info) return;
for (i = 0; info[i].type != DOM_SCAN_END; i++) {
const struct dom_string *data = &info[i].data;
if (info[i].type == DOM_SCAN_RANGE) {
int index = *data->string;
assert(index > 0);
assert(data->length < DOM_SCAN_TABLE_SIZE);
assert(index <= data->length);
for (; index <= data->length; index++)
scan_table[index] |= info[i].bits;
} else {
unsigned char *string = info[i].data.string;
int pos = info[i].data.length - 1;
assert(info[i].type == DOM_SCAN_STRING && pos >= 0);
for (; pos >= 0; pos--)
scan_table[string[pos]] |= info[i].bits;
}
}
}
void
init_dom_scanner(struct dom_scanner *scanner, struct dom_scanner_info *scanner_info,
struct dom_string *string, int state, int count_lines, int complete,
int check_complete, int detect_errors)
{
if (!scanner_info->initialized) {
init_dom_scanner_info(scanner_info);
scanner_info->initialized = 1;
}
memset(scanner, 0, sizeof(*scanner));
scanner->string = string->string;
scanner->position = string->string;
scanner->end = string->string + string->length;
scanner->current = scanner->table;
scanner->info = scanner_info;
scanner->state = state;
scanner->count_lines = !!count_lines;
scanner->incomplete = !complete;
scanner->check_complete = !!check_complete;
scanner->detect_errors = !!detect_errors;
scanner->lineno = scanner->count_lines;
scanner->info->scan(scanner);
}