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Diffstat (limited to 'expr.h')
-rw-r--r-- | expr.h | 225 |
1 files changed, 225 insertions, 0 deletions
@@ -0,0 +1,225 @@ +/**************************************************************************** + * bfs * + * Copyright (C) 2015-2017 Tavian Barnes <tavianator@tavianator.com> * + * * + * Permission to use, copy, modify, and/or distribute this software for any * + * purpose with or without fee is hereby granted. * + * * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * + ****************************************************************************/ + +#ifndef EXPR_H +#define EXPR_H + +#include "color.h" +#include "exec.h" +#include "printf.h" +#include <regex.h> +#include <stdbool.h> +#include <stddef.h> +#include <sys/types.h> +#include <time.h> + +/** + * A command line expression. + */ +struct expr; + +/** + * Ephemeral state for evaluating an expression. + */ +struct eval_state; + +/** + * Expression evaluation function. + * + * @param expr + * The current expression. + * @param state + * The current evaluation state. + * @return + * The result of the test. + */ +typedef bool eval_fn(const struct expr *expr, struct eval_state *state); + +/** + * Possible types of numeric comparison. + */ +enum cmp_flag { + /** Exactly n. */ + CMP_EXACT, + /** Less than n. */ + CMP_LESS, + /** Greater than n. */ + CMP_GREATER, +}; + +/** + * Possible types of mode comparison. + */ +enum mode_cmp { + /** Mode is an exact match (MODE). */ + MODE_EXACT, + /** Mode has all these bits (-MODE). */ + MODE_ALL, + /** Mode has any of these bits (/MODE). */ + MODE_ANY, +}; + +/** + * Available struct stat time fields. + */ +enum time_field { + /** Access time. */ + ATIME, + /** Status change time. */ + CTIME, + /** Modification time. */ + MTIME, +}; + +/** + * Possible time units. + */ +enum time_unit { + /** Minutes. */ + MINUTES, + /** Days. */ + DAYS, +}; + +/** + * Possible file size units. + */ +enum size_unit { + /** 512-byte blocks. */ + SIZE_BLOCKS, + /** Single bytes. */ + SIZE_BYTES, + /** Two-byte words. */ + SIZE_WORDS, + /** Kibibytes. */ + SIZE_KB, + /** Mebibytes. */ + SIZE_MB, + /** Gibibytes. */ + SIZE_GB, + /** Tebibytes. */ + SIZE_TB, + /** Pebibytes. */ + SIZE_PB, +}; + +struct expr { + /** The function that evaluates this expression. */ + eval_fn *eval; + + /** The left hand side of the expression. */ + struct expr *lhs; + /** The right hand side of the expression. */ + struct expr *rhs; + + /** Whether this expression has no side effects. */ + bool pure; + /** Whether this expression always evaluates to true. */ + bool always_true; + /** Whether this expression always evaluates to false. */ + bool always_false; + + /** Estimated cost. */ + double cost; + /** Estimated probability of success. */ + double probability; + /** Number of times this predicate was executed. */ + size_t evaluations; + /** Number of times this predicate succeeded. */ + size_t successes; + /** Total time spent running this predicate. */ + struct timespec elapsed; + + /** The number of command line arguments for this expression. */ + size_t argc; + /** The command line arguments comprising this expression. */ + char **argv; + + /** The optional comparison flag. */ + enum cmp_flag cmp_flag; + + /** The mode comparison flag. */ + enum mode_cmp mode_cmp; + /** Mode to use for files. */ + mode_t file_mode; + /** Mode to use for directories (different due to X). */ + mode_t dir_mode; + + /** The optional reference time. */ + struct timespec reftime; + /** The optional time field. */ + enum time_field time_field; + /** The optional time unit. */ + enum time_unit time_unit; + + /** The optional size unit. */ + enum size_unit size_unit; + + /** Optional device number for a target file. */ + dev_t dev; + /** Optional inode number for a target file. */ + ino_t ino; + + /** File to output to. */ + CFILE *cfile; + + /** Optional compiled regex. */ + regex_t *regex; + + /** Optional exec command. */ + struct bfs_exec *execbuf; + + /** Optional printf command. */ + struct bfs_printf *printf; + + /** Optional integer data for this expression. */ + long long idata; + + /** Optional string data for this expression. */ + const char *sdata; +}; + +/** Singleton true expression instance. */ +extern struct expr expr_true; +/** Singleton false expression instance. */ +extern struct expr expr_false; + +/** + * Create a new expression. + */ +struct expr *new_expr(eval_fn *eval, size_t argc, char **argv); + +/** + * @return Whether expr is known to always quit. + */ +bool expr_never_returns(const struct expr *expr); + +/** + * @return The result of the comparison for this expression. + */ +bool expr_cmp(const struct expr *expr, long long n); + +/** + * Dump a parsed expression. + */ +void dump_expr(CFILE *cfile, const struct expr *expr, bool verbose); + +/** + * Free an expression tree. + */ +void free_expr(struct expr *expr); + +#endif // EXPR_H |