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/* SPDX-License-Identifier: GPL-2.0 */
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdbool.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <inttypes.h>
#include <fnmatch.h>
#include <regex.h>
#include <assert.h>
#include <lopsub.h>
#include "err.h"
/* Opaque, only known to ast.c. Passed to the generated txp_yyparse(). */
struct txp_context;
/*
* Since we use a reentrant lexer, all functions generated by flex(1)
* receive an additional argument of this type.
*/
typedef void *txp_yyscan_t;
/* Parsed regex pattern. */
struct txp_re_pattern {
regex_t preg; /* Pre-compiled regex. */
unsigned flags; /* Subset of the cflags described in regex(3). */
};
/*
* The possible values of a node in the abstract syntax tree (AST).
*
* Constant semantic values (string literals, numeric constants and regex
* patterns which are part of the tag expression) are determined during
* txp_init() while values which depend on the epigram (tags, number of lines,
* etc.) are determined during txp_eval_row().
*
* This union, and the txp_ast_node structure below are used extensively in
* txp.y. However, both need to be public because the lexer must be able to
* create AST nodes for the constant semantic values.
*/
union txp_semantic_value {
bool boolval; /* Comparators, =~ and =|. */
char *strval; /* String literals, tags, path. */
int64_t intval; /* Constants, bitrate, frequency, etc. */
struct txp_re_pattern re_pattern; /*< Right-hand side operand of =~. */
};
/*
* A node is either interior or a leaf node. Interior nodes have at least one
* child while leaf nodes have a semantic value and no children.
*
* Examples: (a) STRING_LITERAL has a semantic value (the unescaped string
* literal) and no children, (b) NEG (unary minus) has no semantic value but
* one child (the numeric expression that is to be negated), (c) LESS_OR_EQUAL
* has no semantic value and two children (the two numeric expressions being
* compared).
*/
struct txp_ast_node {
/* Corresponds to a token type, for example LESS_OR_EQUAL. */
int id;
union {
/* Pointers to the child nodes (interior nodes only). */
struct txp_ast_node **children;
/* Leaf nodes only. */
union txp_semantic_value sv;
};
/*
* The number of children is implicitly given by the id, but we include
* it here to avoid having to maintain a lookup table. The AST is
* usually small, so we can afford to waste a byte per node.
*/
uint8_t num_children;
};
enum loglevels {LOGLEVELS, NUM_LOGLEVELS};
#define DEBUG_LOG(f,...) txp_log(LL_DEBUG, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
#define INFO_LOG(f,...) txp_log(LL_INFO, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
#define NOTICE_LOG(f,...) txp_log(LL_NOTICE, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
#define WARNING_LOG(f,...) txp_log(LL_WARNING, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
#define ERROR_LOG(f,...) txp_log(LL_ERROR, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
#define CRIT_LOG(f,...) txp_log(LL_CRIT, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
#define EMERG_LOG(f,...) txp_log(LL_EMERG, "%s: " f, __FUNCTION__, ## __VA_ARGS__)
/* tfortune.c */
void txp_log(int ll, const char* fmt,...);
/* Called from both the lexer and the parser. */
__attribute__ ((format (printf, 3, 4)))
void txp_parse_error(int line, struct txp_context *ctx, const char *fmt, ...);
/* Helper functions for the lexer. */
unsigned parse_quoted_string(const char *src, const char quote_chars[2],
char **result);
int txp_parse_regex_pattern(const char *src, struct txp_re_pattern *result);
/* ast.c */
struct txp_ast_node *ast_node_new_unary(int id, struct txp_ast_node *child);
struct txp_ast_node *ast_node_new_binary(int id, struct txp_ast_node *left,
struct txp_ast_node *right);
/*
* Allocate a new leaf node for the abstract syntax tree.
*
* This returns a pointer to a node whose ->num_children field is initialized
* to zero. The ->id field is initialized with the given id. The caller is
* expected to initialize the ->sv field.
*/
struct txp_ast_node *txp_new_ast_leaf_node(int id);
/*
* Evaluate an abstract syntax tree, starting at the root node.
*
* The root node argument should be the pointer that was returned from an
* earlier call to txp_init() via the context pointer. The context contains the
* information about the epigram.
*
* Returns true if the AST evaluates to true, a non-empty string, or a non-zero
* number, false otherwise.
*/
bool txp_eval_ast(struct txp_ast_node *root, struct txp_context *ctx);
/*
* Deallocate an abstract syntax tree.
*
* This frees the memory occupied by the nodes of the AST, the child pointers
* of the internal nodes and the (constant) semantic values of the leaf nodes
* (string literals and pre-compiled regular expressions).
*/
void txp_free_ast(struct txp_ast_node *root);
/* util.c */
int atoi64(const char *str, int64_t *value);
unsigned xvasprintf(char **result, const char *fmt, va_list ap);
unsigned xasprintf(char **result, const char *fmt, ...);
void *xmalloc(size_t size);
void *xcalloc(size_t size);
int xregcomp(regex_t *preg, const char *regex, int cflags);
/* txp.c */
/* txp.y. */
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