From: Will Dyson Add documentation and comments to lib/parser.c and include/linux/parser.h include/linux/parser.h | 16 ++++++++- lib/parser.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 93 insertions(+), 2 deletions(-) diff -puN include/linux/parser.h~document-lib-parser include/linux/parser.h --- 25/include/linux/parser.h~document-lib-parser 2003-11-16 15:04:13.000000000 -0800 +++ 25-akpm/include/linux/parser.h 2003-11-16 15:04:13.000000000 -0800 @@ -1,3 +1,14 @@ +/* + * linux/include/linux/parser.h + * + * Header for lib/parser.c + * Intended use of these functions is parsing filesystem argument lists, + * but could potentially be used anywhere else that simple option=arg + * parsing is required. + */ + + +/* associates an integer enumerator with a pattern string. */ struct match_token { int token; char *pattern; @@ -5,15 +16,16 @@ struct match_token { typedef struct match_token match_table_t[]; +/* Maximum number of arguments that match_token will find in a pattern */ enum {MAX_OPT_ARGS = 3}; +/* Describe the location within a string of a substring */ typedef struct { char *from; char *to; } substring_t; -int match_token(char *s, match_table_t table, substring_t args[]); - +int match_token(char *, match_table_t table, substring_t args[]); int match_int(substring_t *, int *result); int match_octal(substring_t *, int *result); int match_hex(substring_t *, int *result); diff -puN lib/parser.c~document-lib-parser lib/parser.c --- 25/lib/parser.c~document-lib-parser 2003-11-16 15:04:13.000000000 -0800 +++ 25-akpm/lib/parser.c 2003-11-16 15:04:13.000000000 -0800 @@ -11,6 +11,17 @@ #include #include +/** + * match_one: - Determines if a string matches a simple pattern + * @s: the string to examine for presense of the pattern + * @p: the string containing the pattern + * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match + * locations. + * + * Description: Determines if the pattern @p is present in string @s. Can only + * match extremely simple token=arg style patterns. If the pattern is found, + * the location(s) of the arguments will be returned in the @args array. + */ static int match_one(char *s, char *p, substring_t args[]) { char *meta; @@ -74,6 +85,20 @@ static int match_one(char *s, char *p, s } } +/** + * match_token: - Find a token (and optional args) in a string + * @s: the string to examine for token/argument pairs + * @table: match_table_t describing the set of allowed option tokens and the + * arguments that may be associated with them. Must be terminated with a + * &struct match_token whose pattern is set to the NULL pointer. + * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match + * locations. + * + * Description: Detects which if any of a set of token strings has been passed + * to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style + * format identifiers which will be taken into account when matching the + * tokens, and whose locations will be returned in the @args array. + */ int match_token(char *s, match_table_t table, substring_t args[]) { struct match_token *p; @@ -84,6 +109,16 @@ int match_token(char *s, match_table_t t return p->token; } +/** + * match_number: scan a number in the given base from a substring_t + * @s: substring to be scanned + * @result: resulting integer on success + * @base: base to use when converting string + * + * Description: Given a &substring_t and a base, attempts to parse the substring + * as a number in that base. On success, sets @result to the integer represented + * by the string and returns 0. Returns either -ENOMEM or -EINVAL on failure. + */ static int match_number(substring_t *s, int *result, int base) { char *endp; @@ -103,27 +138,71 @@ static int match_number(substring_t *s, return ret; } +/** + * match_int: - scan a decimal representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as a decimal integer. On + * success, sets @result to the integer represented by the string and returns 0. + * Returns either -ENOMEM or -EINVAL on failure. + */ int match_int(substring_t *s, int *result) { return match_number(s, result, 0); } +/** + * match_octal: - scan an octal representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as an octal integer. On + * success, sets @result to the integer represented by the string and returns + * 0. Returns either -ENOMEM or -EINVAL on failure. + */ int match_octal(substring_t *s, int *result) { return match_number(s, result, 8); } +/** + * match_hex: - scan a hex representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as a hexadecimal integer. + * On success, sets @result to the integer represented by the string and + * returns 0. Returns either -ENOMEM or -EINVAL on failure. + */ int match_hex(substring_t *s, int *result) { return match_number(s, result, 16); } +/** + * match_strcpy: - copies the characters from a substring_t to a string + * @to: string to copy characters to. + * @s: &substring_t to copy + * + * Description: Copies the set of characters represented by the given + * &substring_t @s to the c-style string @to. Caller guarantees that @to is + * large enough to hold the characters of @s. + */ void match_strcpy(char *to, substring_t *s) { memcpy(to, s->from, s->to - s->from); to[s->to - s->from] = '\0'; } +/** + * match_strdup: - allocate a new string with the contents of a substring_t + * @s: &substring_t to copy + * + * Description: Allocates and returns a string filled with the contents of + * the &substring_t @s. The caller is responsible for freeing the returned + * string with kfree(). + */ char *match_strdup(substring_t *s) { char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL); _