mirror of
https://github.com/rkd77/elinks.git
synced 2024-11-01 08:47:24 -04:00
acf2ec806b
A left over from the CVS Id removal. Also, for a few files, normalize the order in which things are declared in headers.
244 lines
8.0 KiB
C
244 lines
8.0 KiB
C
#ifndef EL__UTIL_SCANNER_H
|
|
#define EL__UTIL_SCANNER_H
|
|
|
|
#include "util/error.h"
|
|
|
|
/* Define if you want a talking scanner */
|
|
/* #define DEBUG_SCANNER */
|
|
|
|
/* The {struct scanner_token} describes one scanner state. There are two kinds
|
|
* of tokens: char and non-char tokens. Char tokens contains only one char and
|
|
* simply have their char value as type. They are tokens having special control
|
|
* meaning in the code, like ':', ';', '{', '}' and '*'. Non char tokens has
|
|
* one or more chars and contain stuff like number or indentifier strings. */
|
|
struct scanner_token {
|
|
/* The type the token */
|
|
int type;
|
|
|
|
/* Some precedence value */
|
|
int precedence;
|
|
|
|
/* The start of the token string and the token length */
|
|
unsigned char *string;
|
|
int length;
|
|
};
|
|
|
|
/* The naming of these two macros is a bit odd .. we compare often with
|
|
* "static" strings (I don't have a better word) so the macro name should
|
|
* be short. --jonas */
|
|
|
|
/* Compare the string of @token with @string */
|
|
#define scanner_token_strlcasecmp(token, str, len) \
|
|
((token) && !strlcasecmp((token)->string, (token)->length, str, len))
|
|
|
|
/* Also compares the token string but using a "static" string */
|
|
#define scanner_token_contains(token, str) \
|
|
scanner_token_strlcasecmp(token, str, sizeof(str) - 1)
|
|
|
|
|
|
struct scan_table_info {
|
|
enum { SCAN_RANGE, SCAN_STRING, SCAN_END } type;
|
|
union scan_table_data {
|
|
struct { unsigned char *source; long length; } string;
|
|
struct { unsigned char *start; long end; } range;
|
|
} data;
|
|
int bits;
|
|
};
|
|
|
|
#define SCAN_TABLE_SIZE 256
|
|
|
|
#define SCAN_TABLE_INFO(type, data1, data2, bits) \
|
|
{ (type), { { (data1), (data2) } }, (bits) }
|
|
|
|
#define SCAN_TABLE_RANGE(from, to, bits) SCAN_TABLE_INFO(SCAN_RANGE, from, to, bits)
|
|
#define SCAN_TABLE_STRING(str, bits) SCAN_TABLE_INFO(SCAN_STRING, str, sizeof(str) - 1, bits)
|
|
#define SCAN_TABLE_END SCAN_TABLE_INFO(SCAN_END, 0, 0, 0)
|
|
|
|
struct scanner_string_mapping {
|
|
unsigned char *name;
|
|
int type;
|
|
int base_type;
|
|
};
|
|
|
|
struct scanner;
|
|
|
|
struct scanner_info {
|
|
/* Table containing how to map strings to token types */
|
|
const struct scanner_string_mapping *mappings;
|
|
|
|
/* Information for how to initialize the scanner table */
|
|
const struct scan_table_info *scan_table_info;
|
|
|
|
/* Fills the scanner with tokens. Already scanned tokens which have not
|
|
* been requested remain and are moved to the start of the scanners
|
|
* token table. */
|
|
/* Returns the current token or NULL if there are none. */
|
|
struct scanner_token *(*scan)(struct scanner *scanner);
|
|
|
|
/* The scanner table */
|
|
/* Contains bitmaps for the various characters groups.
|
|
* Idea sync'ed from mozilla browser. */
|
|
int scan_table[SCAN_TABLE_SIZE];
|
|
|
|
/* Has the scanner info been initialized? */
|
|
unsigned int initialized:1;
|
|
};
|
|
|
|
|
|
/* Initializes the scanner. */
|
|
void init_scanner(struct scanner *scanner, struct scanner_info *scanner_info,
|
|
unsigned char *string, unsigned char *end);
|
|
|
|
/* The number of tokens in the scanners token table:
|
|
* At best it should be big enough to contain properties with space separated
|
|
* values and function calls with up to 3 variables like rgb(). At worst it
|
|
* should be no less than 2 in order to be able to peek at the next token in
|
|
* the scanner. */
|
|
#define SCANNER_TOKENS 10
|
|
|
|
/* The {struct scanner} describes the current state of the scanner. */
|
|
struct scanner {
|
|
/* The very start of the scanned string, the position in the string
|
|
* where to scan next and the end of the string. If position is NULL it
|
|
* means that no more tokens can be retrieved from the string. */
|
|
unsigned char *string, *position, *end;
|
|
|
|
/* The current token and number of scanned tokens in the table.
|
|
* If the number of scanned tokens is less than SCANNER_TOKENS
|
|
* it is because there are no more tokens in the string. */
|
|
struct scanner_token *current;
|
|
int tokens;
|
|
|
|
/* The 'meta' scanner information */
|
|
struct scanner_info *info;
|
|
|
|
#ifdef DEBUG_SCANNER
|
|
/* Debug info about the caller. */
|
|
unsigned char *file;
|
|
int line;
|
|
#endif
|
|
|
|
/* Some state indicator only meaningful to the scanner internals */
|
|
int state;
|
|
|
|
/* The table contain already scanned tokens. It is maintained in
|
|
* order to optimize the scanning a bit and make it possible to look
|
|
* ahead at the next token. You should always use the accessors
|
|
* (defined below) for getting tokens from the scanner. */
|
|
struct scanner_token table[SCANNER_TOKENS];
|
|
};
|
|
|
|
#define scanner_has_tokens(scanner) \
|
|
((scanner)->tokens > 0 && (scanner)->current < (scanner)->table + (scanner)->tokens)
|
|
|
|
/* This macro checks if the current scanner state is valid. Meaning if the
|
|
* scanners table is full the last token skipping or get_next_scanner_token()
|
|
* call made it possible to get the type of the next token. */
|
|
#define check_scanner(scanner) \
|
|
(scanner->tokens < SCANNER_TOKENS \
|
|
|| scanner->current + 1 < scanner->table + scanner->tokens)
|
|
|
|
|
|
/* Scanner table accessors and mutators */
|
|
|
|
/* Checks the type of the next token */
|
|
#define check_next_scanner_token(scanner, token_type) \
|
|
(scanner_has_tokens(scanner) \
|
|
&& ((scanner)->current + 1 < (scanner)->table + (scanner)->tokens) \
|
|
&& (scanner)->current[1].type == (token_type))
|
|
|
|
/* Access current and next token. Getting the next token might cause
|
|
* a rescan so any token pointers that has been stored in a local variable
|
|
* might not be valid after the call. */
|
|
static inline struct scanner_token *
|
|
get_scanner_token(struct scanner *scanner)
|
|
{
|
|
return scanner_has_tokens(scanner) ? scanner->current : NULL;
|
|
}
|
|
|
|
/* Do a scanning if we do not have also have access to next token. */
|
|
static inline struct scanner_token *
|
|
get_next_scanner_token(struct scanner *scanner)
|
|
{
|
|
return (scanner_has_tokens(scanner)
|
|
&& (++scanner->current + 1 >= scanner->table + scanner->tokens)
|
|
? scanner->info->scan(scanner) : get_scanner_token(scanner));
|
|
}
|
|
|
|
/* This should just make the code more understandable .. hopefully */
|
|
#define skip_scanner_token(scanner) get_next_scanner_token(scanner)
|
|
|
|
/* Removes tokens from the scanner until it meets a token of the given type.
|
|
* This token will then also be skipped. */
|
|
struct scanner_token *
|
|
skip_scanner_tokens(struct scanner *scanner, int skipto, int precedence);
|
|
|
|
/* Looks up the string from @ident to @end to in the scanners string mapping
|
|
* table */
|
|
int
|
|
map_scanner_string(struct scanner *scanner,
|
|
unsigned char *ident, unsigned char *end, int base_type);
|
|
|
|
#ifdef DEBUG_SCANNER
|
|
void dump_scanner(struct scanner *scanner);
|
|
#endif
|
|
|
|
/* The begin_token_scanning() and end_token_scanning() functions provide the
|
|
* basic setup and teardown for the rescan function made public via the
|
|
* scanner_info->scan member. */
|
|
|
|
/* Returns NULL if it is not necessary to try to scan for more tokens */
|
|
static inline struct scanner_token *
|
|
begin_token_scanning(struct scanner *scanner)
|
|
{
|
|
struct scanner_token *table = scanner->table;
|
|
struct scanner_token *table_end = table + scanner->tokens;
|
|
int move_to_front = int_max(table_end - scanner->current, 0);
|
|
struct scanner_token *current = move_to_front ? scanner->current : table;
|
|
size_t moved_size = 0;
|
|
|
|
assert(scanner->current);
|
|
|
|
/* Move any untouched tokens */
|
|
if (move_to_front) {
|
|
moved_size = move_to_front * sizeof(*table);
|
|
memmove(table, current, moved_size);
|
|
current = &table[move_to_front];
|
|
}
|
|
|
|
/* Clear all unused tokens */
|
|
memset(current, 0, sizeof(*table) * SCANNER_TOKENS - moved_size);
|
|
|
|
if (!scanner->position) {
|
|
scanner->tokens = move_to_front ? move_to_front : -1;
|
|
scanner->current = table;
|
|
assert(check_scanner(scanner));
|
|
return NULL;
|
|
}
|
|
|
|
scanner->tokens = move_to_front;
|
|
|
|
return table;
|
|
}
|
|
|
|
/* Updates the @scanner struct after scanning has been done. The position
|
|
* _after_ the last valid token is taken as the @end argument. */
|
|
/* It is ok for @end to be < scanner->table since scanner->tokens will become
|
|
* <= 0 anyway. */
|
|
static inline struct scanner_token *
|
|
end_token_scanning(struct scanner *scanner, struct scanner_token *end)
|
|
{
|
|
assert(end <= scanner->table + SCANNER_TOKENS);
|
|
|
|
scanner->tokens = (end - scanner->table);
|
|
scanner->current = scanner->table;
|
|
if (scanner->position >= scanner->end)
|
|
scanner->position = NULL;
|
|
|
|
assert(check_scanner(scanner));
|
|
|
|
return get_scanner_token(scanner);
|
|
}
|
|
|
|
#endif
|