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git/grep.h
Ævar Arnfjörð Bjarmason db84376f98 grep.c: remove "extended" in favor of "pattern_expression", fix segfault
Since 79d3696cfb (git-grep: boolean expression on pattern matching.,
2006-06-30) the "pattern_expression" member has been used for complex
queries (AND/OR...), with "pattern_list" being used for the simple OR
queries. Since then we've used both "pattern_expression" and its
associated boolean "extended" member to see if we have a complex
expression.

Since f41fb662f5 (revisions API: have release_revisions() release
"grep_filter", 2022-04-13) we've had a subtle bug relating to that: If
we supplied options that were only used for "complex queries", but
didn't supply the query itself we'd set "opt->extended", but would
have a NULL "pattern_expression". As a result these would segfault as
we tried to call "free_grep_patterns()" from "release_revisions()":

	git -P log -1 --invert-grep
	git -P log -1 --all-match

The root cause of this is that we were conflating the state management
we needed in "compile_grep_patterns()" itself with whether or not we
had an "opt->pattern_expression" later on.

In this cases as we're going through "compile_grep_patterns()" we have
no "opt->pattern_list" but have "opt->no_body_match" or
"opt->all_match". So we'd set "opt->extended = 1", but not "return" on
"opt->extended" as that's an "else if" in the same "if" statement.

That behavior is intentional and required, as the common case is that
we have an "opt->pattern_list" that we're about to parse into the
"opt->pattern_expression".

But we don't need to keep track of this "extended" flag beyond the
state management in compile_grep_patterns() itself. It needs it, but
once we're out of that function we can rely on
"opt->pattern_expression" being non-NULL instead for using these
extended patterns.

As 79d3696cfb itself shows we've assumed that there's a one-to-one
mapping between the two since the very beginning. I.e. "match_line()"
would check "opt->extended" to see if it should call "match_expr()",
and the first thing we do in that function is assume that we have a
"opt->pattern_expression". We'd then call "match_expr_eval()", which
would have died if that "opt->pattern_expression" was NULL.

The "die" was added in c922b01f54 (grep: fix segfault when "git grep
'('" is given, 2009-04-27), and can now be removed as it's now clearly
unreachable. We still do the right thing in the case that prompted
that fix:

	git grep '('
	fatal: unmatched parenthesis

Arguably neither the "--invert-grep" option added in [1] nor the
earlier "--all-match" option added in [2] were intended to be used
stand-alone, and another approach[3] would be to error out in those
cases. But since we've been treating them as a NOOP when given without
--grep for a long time let's keep doing that.

We could also return in "free_pattern_expr()" if the argument is
non-NULL, as an alternative fix for this segfault does [4]. That would
be more elegant in making the "free_*()" function behave like
"free()", but it would also remove a sanity check: The
"free_pattern_expr()" function calls itself recursively, and only the
top-level is allowed to be NULL, let's not conflate those two
conditions.

1. 22dfa8a23d (log: teach --invert-grep option, 2015-01-12)
2. 0ab7befa31 (grep --all-match, 2006-09-27)
3. https://lore.kernel.org/git/patch-1.1-f4b90799fce-20221010T165711Z-avarab@gmail.com/
4. http://lore.kernel.org/git/7e094882c2a71894416089f894557a9eae07e8f8.1665423686.git.me@ttaylorr.com

Reported-by: orygaw <orygaw@protonmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-11 08:48:54 -07:00

260 lines
6.4 KiB
C

#ifndef GREP_H
#define GREP_H
#include "color.h"
#ifdef USE_LIBPCRE2
#define PCRE2_CODE_UNIT_WIDTH 8
#include <pcre2.h>
#if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 36) || PCRE2_MAJOR >= 11
#define GIT_PCRE2_VERSION_10_36_OR_HIGHER
#endif
#if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 34) || PCRE2_MAJOR >= 11
#define GIT_PCRE2_VERSION_10_34_OR_HIGHER
#endif
#else
typedef int pcre2_code;
typedef int pcre2_match_data;
typedef int pcre2_compile_context;
typedef int pcre2_general_context;
#endif
#ifndef PCRE2_MATCH_INVALID_UTF
/* PCRE2_MATCH_* dummy also with !USE_LIBPCRE2, for test-pcre2-config.c */
#define PCRE2_MATCH_INVALID_UTF 0
#endif
#include "thread-utils.h"
#include "userdiff.h"
struct repository;
enum grep_pat_token {
GREP_PATTERN,
GREP_PATTERN_HEAD,
GREP_PATTERN_BODY,
GREP_AND,
GREP_OPEN_PAREN,
GREP_CLOSE_PAREN,
GREP_NOT,
GREP_OR
};
enum grep_context {
GREP_CONTEXT_HEAD,
GREP_CONTEXT_BODY
};
enum grep_header_field {
GREP_HEADER_FIELD_MIN = 0,
GREP_HEADER_AUTHOR = GREP_HEADER_FIELD_MIN,
GREP_HEADER_COMMITTER,
GREP_HEADER_REFLOG,
/* Must be at the end of the enum */
GREP_HEADER_FIELD_MAX
};
enum grep_color {
GREP_COLOR_CONTEXT,
GREP_COLOR_FILENAME,
GREP_COLOR_FUNCTION,
GREP_COLOR_LINENO,
GREP_COLOR_COLUMNNO,
GREP_COLOR_MATCH_CONTEXT,
GREP_COLOR_MATCH_SELECTED,
GREP_COLOR_SELECTED,
GREP_COLOR_SEP,
NR_GREP_COLORS
};
struct grep_pat {
struct grep_pat *next;
const char *origin;
int no;
enum grep_pat_token token;
char *pattern;
size_t patternlen;
enum grep_header_field field;
regex_t regexp;
pcre2_code *pcre2_pattern;
pcre2_match_data *pcre2_match_data;
pcre2_compile_context *pcre2_compile_context;
pcre2_general_context *pcre2_general_context;
const uint8_t *pcre2_tables;
uint32_t pcre2_jit_on;
unsigned fixed:1;
unsigned is_fixed:1;
unsigned ignore_case:1;
unsigned word_regexp:1;
};
enum grep_expr_node {
GREP_NODE_ATOM,
GREP_NODE_NOT,
GREP_NODE_AND,
GREP_NODE_TRUE,
GREP_NODE_OR
};
enum grep_pattern_type {
GREP_PATTERN_TYPE_UNSPECIFIED = 0,
GREP_PATTERN_TYPE_BRE,
GREP_PATTERN_TYPE_ERE,
GREP_PATTERN_TYPE_FIXED,
GREP_PATTERN_TYPE_PCRE
};
struct grep_expr {
enum grep_expr_node node;
unsigned hit;
union {
struct grep_pat *atom;
struct grep_expr *unary;
struct {
struct grep_expr *left;
struct grep_expr *right;
} binary;
} u;
};
struct grep_opt {
struct grep_pat *pattern_list;
struct grep_pat **pattern_tail;
struct grep_pat *header_list;
struct grep_pat **header_tail;
struct grep_expr *pattern_expression;
/*
* NEEDSWORK: See if we can remove this field, because the repository
* should probably be per-source. That is, grep.c functions using this
* field should probably start using "repo" in "struct grep_source"
* instead.
*
* This is potentially the cause of at least one bug - "git grep"
* using the textconv attributes from the superproject on the
* submodules. See the failing "git grep --textconv" tests in
* t7814-grep-recurse-submodules.sh for more information.
*/
struct repository *repo;
int linenum;
int columnnum;
int invert;
int ignore_case;
int status_only;
int name_only;
int unmatch_name_only;
int count;
int word_regexp;
int all_match;
int no_body_match;
int body_hit;
#define GREP_BINARY_DEFAULT 0
#define GREP_BINARY_NOMATCH 1
#define GREP_BINARY_TEXT 2
int binary;
int allow_textconv;
int use_reflog_filter;
int relative;
int pathname;
int null_following_name;
int only_matching;
int color;
int max_depth;
int funcname;
int funcbody;
int extended_regexp_option;
enum grep_pattern_type pattern_type_option;
int ignore_locale;
char colors[NR_GREP_COLORS][COLOR_MAXLEN];
unsigned pre_context;
unsigned post_context;
unsigned last_shown;
int show_hunk_mark;
int file_break;
int heading;
void *priv;
void (*output)(struct grep_opt *opt, const void *data, size_t size);
void *output_priv;
};
#define GREP_OPT_INIT { \
.relative = 1, \
.pathname = 1, \
.max_depth = -1, \
.pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED, \
.colors = { \
[GREP_COLOR_CONTEXT] = "", \
[GREP_COLOR_FILENAME] = GIT_COLOR_MAGENTA, \
[GREP_COLOR_FUNCTION] = "", \
[GREP_COLOR_LINENO] = GIT_COLOR_GREEN, \
[GREP_COLOR_COLUMNNO] = GIT_COLOR_GREEN, \
[GREP_COLOR_MATCH_CONTEXT] = GIT_COLOR_BOLD_RED, \
[GREP_COLOR_MATCH_SELECTED] = GIT_COLOR_BOLD_RED, \
[GREP_COLOR_SELECTED] = "", \
[GREP_COLOR_SEP] = GIT_COLOR_CYAN, \
}, \
.only_matching = 0, \
.color = -1, \
.output = std_output, \
}
int grep_config(const char *var, const char *value, void *);
void grep_init(struct grep_opt *, struct repository *repo);
void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen, const char *origin, int no, enum grep_pat_token t);
void append_grep_pattern(struct grep_opt *opt, const char *pat, const char *origin, int no, enum grep_pat_token t);
void append_header_grep_pattern(struct grep_opt *, enum grep_header_field, const char *);
void compile_grep_patterns(struct grep_opt *opt);
void free_grep_patterns(struct grep_opt *opt);
int grep_buffer(struct grep_opt *opt, const char *buf, unsigned long size);
/* The field parameter is only used to filter header patterns
* (where appropriate). If filtering isn't desirable
* GREP_HEADER_FIELD_MAX should be supplied.
*/
int grep_next_match(struct grep_opt *opt,
const char *bol, const char *eol,
enum grep_context ctx, regmatch_t *pmatch,
enum grep_header_field field, int eflags);
struct grep_source {
char *name;
enum grep_source_type {
GREP_SOURCE_OID,
GREP_SOURCE_FILE,
GREP_SOURCE_BUF,
} type;
void *identifier;
struct repository *repo; /* if GREP_SOURCE_OID */
const char *buf;
unsigned long size;
char *path; /* for attribute lookups */
struct userdiff_driver *driver;
};
void grep_source_init_file(struct grep_source *gs, const char *name,
const char *path);
void grep_source_init_oid(struct grep_source *gs, const char *name,
const char *path, const struct object_id *oid,
struct repository *repo);
void grep_source_clear_data(struct grep_source *gs);
void grep_source_clear(struct grep_source *gs);
void grep_source_load_driver(struct grep_source *gs,
struct index_state *istate);
int grep_source(struct grep_opt *opt, struct grep_source *gs);
struct grep_opt *grep_opt_dup(const struct grep_opt *opt);
/*
* Mutex used around access to the attributes machinery if
* opt->use_threads. Must be initialized/destroyed by callers!
*/
extern int grep_use_locks;
extern pthread_mutex_t grep_attr_mutex;
#endif