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git/dir.h
Jeff King eed1fbe73b dir.c: always copy input to add_pattern()
The add_pattern() function has a subtle and undocumented gotcha: the
pattern string you pass in must remain valid as long as the pattern_list
is in use (and nor do we take ownership of it). This is easy to get
wrong, causing either subtle bugs (because you free or reuse the string
buffer) or leaks (because you copy the string, but don't track ownership
separately).

All of this "pattern" code was originally the "exclude" mechanism. So
this _usually_ works OK because you add entries in one of two ways:

  1. From the command-line (e.g., "--exclude"), in which case we're
     pointing to an argv entry which remains valid for the lifetime of
     the program.

  2. From a file (e.g., ".gitignore"), in which case we read the whole
     file into a buffer, attach it to the pattern_list's "filebuf"
     entry, then parse the buffer in-place (adding NULs). The strings
     point into the filebuf, which is cleaned up when the whole
     pattern_list goes away.

But other code, like sparse-checkout, reads individual lines from stdin
and passes them one by one to add_pattern(), leaking each. We could fix
this by refactoring it to take in the whole buffer at once, like (2)
above, and stuff it in "filebuf". But given how subtle the interface is,
let's just fix it to always copy the string.

That seems at first like we'd be wasting extra memory, but we can
mitigate that:

  a. The path_pattern struct already uses a FLEXPTR, since we sometimes
     make a copy (when we see "foo/", we strip off the trailing slash,
     requiring a modifiable copy of the string).

     Since we'll now always embed the string inside the struct, we can
     switch to the regular FLEX_ARRAY pattern, saving us 8 bytes of
     pointer. So patterns with a trailing slash and ones under 8 bytes
     actually get smaller.

  b. Now that we don't need the original string to hang around, we can
     get rid of the "filebuf" mechanism entirely, and just free the file
     contents after parsing. Since files are the sources we'd expect to
     have the largest pattern sets, we should mostly break even on
     stuffing the same data into the individual structs.

This patch just adjusts the add_pattern() interface; it doesn't fix any
leaky callers yet.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-05 09:51:42 -07:00

678 lines
21 KiB
C

#ifndef DIR_H
#define DIR_H
#include "hash-ll.h"
#include "hashmap.h"
#include "pathspec.h"
#include "statinfo.h"
#include "strbuf.h"
struct repository;
/**
* The directory listing API is used to enumerate paths in the work tree,
* optionally taking `.git/info/exclude` and `.gitignore` files per directory
* into account.
*/
/**
* Calling sequence
* ----------------
*
* Note: The index may be checked for .gitignore files that are
* CE_SKIP_WORKTREE marked. If you want to exclude files, make sure you have
* loaded the index first.
*
* - Prepare `struct dir_struct dir` using `dir_init()` function.
*
* - To add single exclude pattern, call `add_pattern_list()` and then
* `add_pattern()`.
*
* - To add patterns from a file (e.g. `.git/info/exclude`), call
* `add_patterns_from_file()` , and/or set `dir.exclude_per_dir`.
*
* - A short-hand function `setup_standard_excludes()` can be used to set
* up the standard set of exclude settings, instead of manually calling
* the add_pattern*() family of functions.
*
* - Call `fill_directory()`.
*
* - Use `dir.entries[]` and `dir.ignored[]`.
*
* - Call `dir_clear()` when the contained elements are no longer in use.
*
*/
struct repository;
struct dir_entry {
unsigned int len;
char name[FLEX_ARRAY]; /* more */
};
#define PATTERN_FLAG_NODIR 1
#define PATTERN_FLAG_ENDSWITH 4
#define PATTERN_FLAG_MUSTBEDIR 8
#define PATTERN_FLAG_NEGATIVE 16
struct path_pattern {
/*
* This allows callers of last_matching_pattern() etc.
* to determine the origin of the matching pattern.
*/
struct pattern_list *pl;
int patternlen;
int nowildcardlen;
const char *base;
int baselen;
unsigned flags; /* PATTERN_FLAG_* */
/*
* Counting starts from 1 for line numbers in ignore files,
* and from -1 decrementing for patterns from CLI args.
*/
int srcpos;
char pattern[FLEX_ARRAY];
};
/* used for hashmaps for cone patterns */
struct pattern_entry {
struct hashmap_entry ent;
char *pattern;
size_t patternlen;
};
/*
* Each excludes file will be parsed into a fresh exclude_list which
* is appended to the relevant exclude_list_group (either EXC_DIRS or
* EXC_FILE). An exclude_list within the EXC_CMDL exclude_list_group
* can also be used to represent the list of --exclude values passed
* via CLI args.
*/
struct pattern_list {
int nr;
int alloc;
/* origin of list, e.g. path to filename, or descriptive string */
const char *src;
struct path_pattern **patterns;
/*
* While scanning the excludes, we attempt to match the patterns
* with a more restricted set that allows us to use hashsets for
* matching logic, which is faster than the linear lookup in the
* excludes array above. If non-zero, that check succeeded.
*/
unsigned use_cone_patterns;
unsigned full_cone;
/*
* Stores paths where everything starting with those paths
* is included.
*/
struct hashmap recursive_hashmap;
/*
* Used to check single-level parents of blobs.
*/
struct hashmap parent_hashmap;
};
/*
* The contents of the per-directory exclude files are lazily read on
* demand and then cached in memory, one per exclude_stack struct, in
* order to avoid opening and parsing each one every time that
* directory is traversed.
*/
struct exclude_stack {
struct exclude_stack *prev; /* the struct exclude_stack for the parent directory */
int baselen;
int exclude_ix; /* index of exclude_list within EXC_DIRS exclude_list_group */
struct untracked_cache_dir *ucd;
};
struct exclude_list_group {
int nr, alloc;
struct pattern_list *pl;
};
struct oid_stat {
struct stat_data stat;
struct object_id oid;
int valid;
};
/*
* Untracked cache
*
* The following inputs are sufficient to determine what files in a
* directory are excluded:
*
* - The list of files and directories of the directory in question
* - The $GIT_DIR/index
* - dir_struct flags
* - The content of $GIT_DIR/info/exclude
* - The content of core.excludesfile
* - The content (or the lack) of .gitignore of all parent directories
* from $GIT_WORK_TREE
* - The check_only flag in read_directory_recursive (for
* DIR_HIDE_EMPTY_DIRECTORIES)
*
* The first input can be checked using directory mtime. In many
* filesystems, directory mtime (stat_data field) is updated when its
* files or direct subdirs are added or removed.
*
* The second one can be hooked from cache_tree_invalidate_path().
* Whenever a file (or a submodule) is added or removed from a
* directory, we invalidate that directory.
*
* The remaining inputs are easy, their SHA-1 could be used to verify
* their contents (exclude_sha1[], info_exclude_sha1[] and
* excludes_file_sha1[])
*/
struct untracked_cache_dir {
struct untracked_cache_dir **dirs;
char **untracked;
struct stat_data stat_data;
unsigned int untracked_alloc, dirs_nr, dirs_alloc;
unsigned int untracked_nr;
unsigned int check_only : 1;
/* all data except 'dirs' in this struct are good */
unsigned int valid : 1;
unsigned int recurse : 1;
/* null object ID means this directory does not have .gitignore */
struct object_id exclude_oid;
char name[FLEX_ARRAY];
};
struct untracked_cache {
struct oid_stat ss_info_exclude;
struct oid_stat ss_excludes_file;
const char *exclude_per_dir;
char *exclude_per_dir_to_free;
struct strbuf ident;
/*
* dir_struct#flags must match dir_flags or the untracked
* cache is ignored.
*/
unsigned dir_flags;
struct untracked_cache_dir *root;
/* Statistics */
int dir_created;
int gitignore_invalidated;
int dir_invalidated;
int dir_opened;
/* fsmonitor invalidation data */
unsigned int use_fsmonitor : 1;
};
/**
* structure is used to pass directory traversal options to the library and to
* record the paths discovered. A single `struct dir_struct` is used regardless
* of whether or not the traversal recursively descends into subdirectories.
*/
struct dir_struct {
/* bit-field of options */
enum {
/**
* Return just ignored files in `entries[]`, not untracked files.
* This flag is mutually exclusive with `DIR_SHOW_IGNORED_TOO`.
*/
DIR_SHOW_IGNORED = 1<<0,
/* Include a directory that is not tracked. */
DIR_SHOW_OTHER_DIRECTORIES = 1<<1,
/* Do not include a directory that is not tracked and is empty. */
DIR_HIDE_EMPTY_DIRECTORIES = 1<<2,
/**
* If set, recurse into a directory that looks like a Git directory.
* Otherwise it is shown as a directory.
*/
DIR_NO_GITLINKS = 1<<3,
/**
* Special mode for git-add. Return ignored files in `ignored[]` and
* untracked files in `entries[]`. Only returns ignored files that match
* pathspec exactly (no wildcards). Does not recurse into ignored
* directories.
*/
DIR_COLLECT_IGNORED = 1<<4,
/**
* Similar to `DIR_SHOW_IGNORED`, but return ignored files in
* `ignored[]` in addition to untracked files in `entries[]`.
* This flag is mutually exclusive with `DIR_SHOW_IGNORED`.
*/
DIR_SHOW_IGNORED_TOO = 1<<5,
DIR_COLLECT_KILLED_ONLY = 1<<6,
/**
* Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is
* set, the untracked contents of untracked directories are also
* returned in `entries[]`.
*/
DIR_KEEP_UNTRACKED_CONTENTS = 1<<7,
/**
* Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is
* set, returns ignored files and directories that match an exclude
* pattern. If a directory matches an exclude pattern, then the
* directory is returned and the contained paths are not. A directory
* that does not match an exclude pattern will not be returned even if
* all of its contents are ignored. In this case, the contents are
* returned as individual entries.
*
* If this is set, files and directories that explicitly match an ignore
* pattern are reported. Implicitly ignored directories (directories that
* do not match an ignore pattern, but whose contents are all ignored)
* are not reported, instead all of the contents are reported.
*/
DIR_SHOW_IGNORED_TOO_MODE_MATCHING = 1<<8,
DIR_SKIP_NESTED_GIT = 1<<9
} flags;
/* The number of members in `entries[]` array. */
int nr; /* output only */
/* The number of members in `ignored[]` array. */
int ignored_nr; /* output only */
/* An array of `struct dir_entry`, each element of which describes a path. */
struct dir_entry **entries; /* output only */
/**
* used for ignored paths with the `DIR_SHOW_IGNORED_TOO` and
* `DIR_COLLECT_IGNORED` flags.
*/
struct dir_entry **ignored; /* output only */
/* Enable/update untracked file cache if set */
struct untracked_cache *untracked;
/**
* Deprecated: ls-files is the only allowed caller; all other callers
* should leave this as NULL; it pre-dated the
* setup_standard_excludes() mechanism that replaces this.
*
* This field tracks the name of the file to be read in each directory
* for excluded files (typically `.gitignore`).
*/
const char *exclude_per_dir;
struct dir_struct_internal {
/* Keeps track of allocation of `entries[]` array.*/
int alloc;
/* Keeps track of allocation of `ignored[]` array. */
int ignored_alloc;
/*
* We maintain three groups of exclude pattern lists:
*
* EXC_CMDL lists patterns explicitly given on the command line.
* EXC_DIRS lists patterns obtained from per-directory ignore
* files.
* EXC_FILE lists patterns from fallback ignore files, e.g.
* - .git/info/exclude
* - core.excludesfile
*
* Each group contains multiple exclude lists, a single list
* per source.
*/
#define EXC_CMDL 0
#define EXC_DIRS 1
#define EXC_FILE 2
struct exclude_list_group exclude_list_group[3];
/*
* Temporary variables which are used during loading of the
* per-directory exclude lists.
*
* exclude_stack points to the top of the exclude_stack, and
* basebuf contains the full path to the current
* (sub)directory in the traversal. Exclude points to the
* matching exclude struct if the directory is excluded.
*/
struct exclude_stack *exclude_stack;
struct path_pattern *pattern;
struct strbuf basebuf;
/* Additional metadata related to 'untracked' */
struct oid_stat ss_info_exclude;
struct oid_stat ss_excludes_file;
unsigned unmanaged_exclude_files;
/* Stats about the traversal */
unsigned visited_paths;
unsigned visited_directories;
} internal;
};
#define DIR_INIT { 0 }
struct dirent *readdir_skip_dot_and_dotdot(DIR *dirp);
/*
* Get the d_type of a dirent. If the d_type is unknown, derive it from
* stat.st_mode using the path to the dirent's containing directory (path) and
* the name of the dirent itself.
*
* If 'follow_symlink' is 1, this function will attempt to follow DT_LNK types
* using 'stat'. Links are *not* followed recursively, so a symlink pointing
* to another symlink will still resolve to 'DT_LNK'.
*
* Note that 'path' is assumed to have a trailing slash. It is also modified
* in-place during the execution of the function, but is then reverted to its
* original value before returning.
*/
unsigned char get_dtype(struct dirent *e, struct strbuf *path,
int follow_symlink);
/*Count the number of slashes for string s*/
int count_slashes(const char *s);
/*
* The ordering of these constants is significant, with
* higher-numbered match types signifying "closer" (i.e. more
* specific) matches which will override lower-numbered match types
* when populating the seen[] array.
*/
#define MATCHED_RECURSIVELY 1
#define MATCHED_RECURSIVELY_LEADING_PATHSPEC 2
#define MATCHED_FNMATCH 3
#define MATCHED_EXACTLY 4
int simple_length(const char *match);
int no_wildcard(const char *string);
char *common_prefix(const struct pathspec *pathspec);
int report_path_error(const char *ps_matched, const struct pathspec *pathspec);
int within_depth(const char *name, int namelen, int depth, int max_depth);
int fill_directory(struct dir_struct *dir,
struct index_state *istate,
const struct pathspec *pathspec);
int read_directory(struct dir_struct *, struct index_state *istate,
const char *path, int len,
const struct pathspec *pathspec);
enum pattern_match_result {
UNDECIDED = -1,
NOT_MATCHED = 0,
MATCHED = 1,
MATCHED_RECURSIVE = 2,
};
/*
* Scan the list of patterns to determine if the ordered list
* of patterns matches on 'pathname'.
*
* Return 1 for a match, 0 for not matched and -1 for undecided.
*/
enum pattern_match_result path_matches_pattern_list(const char *pathname,
int pathlen,
const char *basename, int *dtype,
struct pattern_list *pl,
struct index_state *istate);
int init_sparse_checkout_patterns(struct index_state *state);
int path_in_sparse_checkout(const char *path,
struct index_state *istate);
int path_in_cone_mode_sparse_checkout(const char *path,
struct index_state *istate);
struct dir_entry *dir_add_ignored(struct dir_struct *dir,
struct index_state *istate,
const char *pathname, int len);
/*
* these implement the matching logic for dir.c:excluded_from_list and
* attr.c:path_matches()
*/
int match_basename(const char *, int,
const char *, int, int, unsigned);
int match_pathname(const char *, int,
const char *, int,
const char *, int, int);
struct path_pattern *last_matching_pattern(struct dir_struct *dir,
struct index_state *istate,
const char *name, int *dtype);
int is_excluded(struct dir_struct *dir,
struct index_state *istate,
const char *name, int *dtype);
int pl_hashmap_cmp(const void *unused_cmp_data,
const struct hashmap_entry *a,
const struct hashmap_entry *b,
const void *key);
int hashmap_contains_parent(struct hashmap *map,
const char *path,
struct strbuf *buffer);
struct pattern_list *add_pattern_list(struct dir_struct *dir,
int group_type, const char *src);
int add_patterns_from_file_to_list(const char *fname, const char *base, int baselen,
struct pattern_list *pl, struct index_state *istate,
unsigned flags);
void add_patterns_from_file(struct dir_struct *, const char *fname);
int add_patterns_from_blob_to_list(struct object_id *oid,
const char *base, int baselen,
struct pattern_list *pl);
void parse_path_pattern(const char **string, int *patternlen, unsigned *flags, int *nowildcardlen);
void add_pattern(const char *string, const char *base,
int baselen, struct pattern_list *pl, int srcpos);
void clear_pattern_list(struct pattern_list *pl);
void dir_clear(struct dir_struct *dir);
int repo_file_exists(struct repository *repo, const char *path);
int file_exists(const char *);
int is_inside_dir(const char *dir);
int dir_inside_of(const char *subdir, const char *dir);
static inline int is_dot_or_dotdot(const char *name)
{
return (name[0] == '.' &&
(name[1] == '\0' ||
(name[1] == '.' && name[2] == '\0')));
}
int is_empty_dir(const char *dir);
/*
* Retrieve the "humanish" basename of the given Git URL.
*
* For example:
* /path/to/repo.git => "repo"
* host.xz:foo/.git => "foo"
* http://example.com/user/bar.baz => "bar.baz"
*/
char *git_url_basename(const char *repo, int is_bundle, int is_bare);
void strip_dir_trailing_slashes(char *dir);
void setup_standard_excludes(struct dir_struct *dir);
char *get_sparse_checkout_filename(void);
int get_sparse_checkout_patterns(struct pattern_list *pl);
/* Constants for remove_dir_recursively: */
/*
* If a non-directory is found within path, stop and return an error.
* (In this case some empty directories might already have been
* removed.)
*/
#define REMOVE_DIR_EMPTY_ONLY 01
/*
* If any Git work trees are found within path, skip them without
* considering it an error.
*/
#define REMOVE_DIR_KEEP_NESTED_GIT 02
/* Remove the contents of path, but leave path itself. */
#define REMOVE_DIR_KEEP_TOPLEVEL 04
/* Remove the_original_cwd too */
#define REMOVE_DIR_PURGE_ORIGINAL_CWD 0x08
/*
* Remove path and its contents, recursively. flags is a combination
* of the above REMOVE_DIR_* constants. Return 0 on success.
*
* This function uses path as temporary scratch space, but restores it
* before returning.
*/
int remove_dir_recursively(struct strbuf *path, int flag);
/*
* Tries to remove the path, along with leading empty directories so long as
* those empty directories are not startup_info->original_cwd. Ignores
* ENOENT.
*/
int remove_path(const char *path);
int fspathcmp(const char *a, const char *b);
int fspatheq(const char *a, const char *b);
int fspathncmp(const char *a, const char *b, size_t count);
unsigned int fspathhash(const char *str);
/*
* Reports whether paths collide. This may be because the paths differ only in
* case on a case-sensitive filesystem, or that one path refers to a symlink
* that collides with one of the parent directories of the other.
*/
int paths_collide(const char *a, const char *b);
/*
* The prefix part of pattern must not contains wildcards.
*/
struct pathspec_item;
int git_fnmatch(const struct pathspec_item *item,
const char *pattern, const char *string,
int prefix);
int submodule_path_match(struct index_state *istate,
const struct pathspec *ps,
const char *submodule_name,
char *seen);
static inline int dir_path_match(struct index_state *istate,
const struct dir_entry *ent,
const struct pathspec *pathspec,
int prefix, char *seen)
{
int has_trailing_dir = ent->len && ent->name[ent->len - 1] == '/';
int len = has_trailing_dir ? ent->len - 1 : ent->len;
return match_pathspec(istate, pathspec, ent->name, len, prefix, seen,
has_trailing_dir);
}
int cmp_dir_entry(const void *p1, const void *p2);
int check_dir_entry_contains(const struct dir_entry *out, const struct dir_entry *in);
void untracked_cache_invalidate_path(struct index_state *, const char *, int safe_path);
/*
* Invalidate the untracked-cache for this path, but first strip
* off a trailing slash, if present.
*/
void untracked_cache_invalidate_trimmed_path(struct index_state *,
const char *path,
int safe_path);
void untracked_cache_remove_from_index(struct index_state *, const char *);
void untracked_cache_add_to_index(struct index_state *, const char *);
void free_untracked_cache(struct untracked_cache *);
struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz);
void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked);
void add_untracked_cache(struct index_state *istate);
void remove_untracked_cache(struct index_state *istate);
/*
* Connect a worktree to a git directory by creating (or overwriting) a
* '.git' file containing the location of the git directory. In the git
* directory set the core.worktree setting to indicate where the worktree is.
* When `recurse_into_nested` is set, recurse into any nested submodules,
* connecting them as well.
*/
void connect_work_tree_and_git_dir(const char *work_tree,
const char *git_dir,
int recurse_into_nested);
void relocate_gitdir(const char *path,
const char *old_git_dir,
const char *new_git_dir);
/**
* The "enum path_matches_kind" determines how path_match_flags() will
* behave. The flags come in sets, and one (and only one) must be
* provided out of each "set":
*
* PATH_MATCH_NATIVE:
* Path separator is is_dir_sep()
* PATH_MATCH_XPLATFORM:
* Path separator is is_xplatform_dir_sep()
*
* Do we use is_dir_sep() to check for a directory separator
* (*_NATIVE), or do we always check for '/' or '\' (*_XPLATFORM). The
* "*_NATIVE" version on Windows is the same as "*_XPLATFORM",
* everywhere else "*_NATIVE" means "only /".
*
* PATH_MATCH_STARTS_WITH_DOT_SLASH:
* Match a path starting with "./"
* PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH:
* Match a path starting with "../"
*
* The "/" in the above is adjusted based on the "*_NATIVE" and
* "*_XPLATFORM" flags.
*/
enum path_match_flags {
PATH_MATCH_NATIVE = 1 << 0,
PATH_MATCH_XPLATFORM = 1 << 1,
PATH_MATCH_STARTS_WITH_DOT_SLASH = 1 << 2,
PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH = 1 << 3,
};
#define PATH_MATCH_KINDS_MASK (PATH_MATCH_STARTS_WITH_DOT_SLASH | \
PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH)
#define PATH_MATCH_PLATFORM_MASK (PATH_MATCH_NATIVE | PATH_MATCH_XPLATFORM)
/**
* path_match_flags() checks if a given "path" matches a given "enum
* path_match_flags" criteria.
*/
int path_match_flags(const char *const path, const enum path_match_flags f);
/**
* starts_with_dot_slash_native(): convenience wrapper for
* path_match_flags() with PATH_MATCH_STARTS_WITH_DOT_SLASH and
* PATH_MATCH_NATIVE.
*/
static inline int starts_with_dot_slash_native(const char *const path)
{
const enum path_match_flags what = PATH_MATCH_STARTS_WITH_DOT_SLASH;
return path_match_flags(path, what | PATH_MATCH_NATIVE);
}
/**
* starts_with_dot_slash_native(): convenience wrapper for
* path_match_flags() with PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH and
* PATH_MATCH_NATIVE.
*/
static inline int starts_with_dot_dot_slash_native(const char *const path)
{
const enum path_match_flags what = PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH;
return path_match_flags(path, what | PATH_MATCH_NATIVE);
}
#endif