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Diffstat (limited to 'lib/exclude.c')
| -rw-r--r-- | lib/exclude.c | 578 |
1 files changed, 578 insertions, 0 deletions
diff --git a/lib/exclude.c b/lib/exclude.c new file mode 100644 index 0000000..df49714 --- /dev/null +++ b/lib/exclude.c @@ -0,0 +1,578 @@ +/* exclude.c -- exclude file names + + Copyright (C) 1992-1994, 1997, 1999-2007, 2009-2011 Free Software + Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert <eggert@twinsun.com> + and Sergey Poznyakoff <gray@gnu.org>. + Thanks to Phil Proudman <phil@proudman51.freeserve.co.uk> + for improvement suggestions. */ + +#include <config.h> + +#include <stdbool.h> + +#include <ctype.h> +#include <errno.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <wctype.h> + +#include "exclude.h" +#include "hash.h" +#include "mbuiter.h" +#include "fnmatch.h" +#include "xalloc.h" +#include "verify.h" + +#if USE_UNLOCKED_IO +# include "unlocked-io.h" +#endif + +/* Non-GNU systems lack these options, so we don't need to check them. */ +#ifndef FNM_CASEFOLD +# define FNM_CASEFOLD 0 +#endif +#ifndef FNM_EXTMATCH +# define FNM_EXTMATCH 0 +#endif +#ifndef FNM_LEADING_DIR +# define FNM_LEADING_DIR 0 +#endif + +verify (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS) + & (FNM_PATHNAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR + | FNM_CASEFOLD | FNM_EXTMATCH)) + == 0); + + +/* Exclusion patterns are grouped into a singly-linked list of + "exclusion segments". Each segment represents a set of patterns + that can be matches using the same algorithm. Non-wildcard + patterns are kept in hash tables, to speed up searches. Wildcard + patterns are stored as arrays of patterns. */ + + +/* An exclude pattern-options pair. The options are fnmatch options + ORed with EXCLUDE_* options. */ + +struct patopts + { + char const *pattern; + int options; + }; + +/* An array of pattern-options pairs. */ + +struct exclude_pattern + { + struct patopts *exclude; + size_t exclude_alloc; + size_t exclude_count; + }; + +enum exclude_type + { + exclude_hash, /* a hash table of excluded names */ + exclude_pattern /* an array of exclude patterns */ + }; + +struct exclude_segment + { + struct exclude_segment *next; /* next segment in list */ + enum exclude_type type; /* type of this segment */ + int options; /* common options for this segment */ + union + { + Hash_table *table; /* for type == exclude_hash */ + struct exclude_pattern pat; /* for type == exclude_pattern */ + } v; + }; + +/* The exclude structure keeps a singly-linked list of exclude segments */ +struct exclude + { + struct exclude_segment *head, *tail; + }; + +/* Return true if str has wildcard characters */ +bool +fnmatch_pattern_has_wildcards (const char *str, int options) +{ + const char *cset = "\\?*[]"; + if (options & FNM_NOESCAPE) + cset++; + while (*str) + { + size_t n = strcspn (str, cset); + if (str[n] == 0) + break; + else if (str[n] == '\\') + { + str += n + 1; + if (*str) + str++; + } + else + return true; + } + return false; +} + +static void +unescape_pattern (char *str) +{ + int inset = 0; + char *q = str; + do + { + if (inset) + { + if (*q == ']') + inset = 0; + } + else if (*q == '[') + inset = 1; + else if (*q == '\\') + q++; + } + while ((*str++ = *q++)); +} + +/* Return a newly allocated and empty exclude list. */ + +struct exclude * +new_exclude (void) +{ + return xzalloc (sizeof *new_exclude ()); +} + +/* Calculate the hash of string. */ +static size_t +string_hasher (void const *data, size_t n_buckets) +{ + char const *p = data; + return hash_string (p, n_buckets); +} + +/* Ditto, for case-insensitive hashes */ +static size_t +string_hasher_ci (void const *data, size_t n_buckets) +{ + char const *p = data; + mbui_iterator_t iter; + size_t value = 0; + + for (mbui_init (iter, p); mbui_avail (iter); mbui_advance (iter)) + { + mbchar_t m = mbui_cur (iter); + wchar_t wc; + + if (m.wc_valid) + wc = towlower (m.wc); + else + wc = *m.ptr; + + value = (value * 31 + wc) % n_buckets; + } + + return value; +} + +/* compare two strings for equality */ +static bool +string_compare (void const *data1, void const *data2) +{ + char const *p1 = data1; + char const *p2 = data2; + return strcmp (p1, p2) == 0; +} + +/* compare two strings for equality, case-insensitive */ +static bool +string_compare_ci (void const *data1, void const *data2) +{ + char const *p1 = data1; + char const *p2 = data2; + return mbscasecmp (p1, p2) == 0; +} + +static void +string_free (void *data) +{ + free (data); +} + +/* Create new exclude segment of given TYPE and OPTIONS, and attach it + to the tail of list in EX */ +static struct exclude_segment * +new_exclude_segment (struct exclude *ex, enum exclude_type type, int options) +{ + struct exclude_segment *sp = xzalloc (sizeof (struct exclude_segment)); + sp->type = type; + sp->options = options; + switch (type) + { + case exclude_pattern: + break; + + case exclude_hash: + sp->v.table = hash_initialize (0, NULL, + (options & FNM_CASEFOLD) ? + string_hasher_ci + : string_hasher, + (options & FNM_CASEFOLD) ? + string_compare_ci + : string_compare, + string_free); + break; + } + if (ex->tail) + ex->tail->next = sp; + else + ex->head = sp; + ex->tail = sp; + return sp; +} + +/* Free a single exclude segment */ +static void +free_exclude_segment (struct exclude_segment *seg) +{ + switch (seg->type) + { + case exclude_pattern: + free (seg->v.pat.exclude); + break; + + case exclude_hash: + hash_free (seg->v.table); + break; + } + free (seg); +} + +/* Free the storage associated with an exclude list. */ +void +free_exclude (struct exclude *ex) +{ + struct exclude_segment *seg; + for (seg = ex->head; seg; ) + { + struct exclude_segment *next = seg->next; + free_exclude_segment (seg); + seg = next; + } + free (ex); +} + +/* Return zero if PATTERN matches F, obeying OPTIONS, except that + (unlike fnmatch) wildcards are disabled in PATTERN. */ + +static int +fnmatch_no_wildcards (char const *pattern, char const *f, int options) +{ + if (! (options & FNM_LEADING_DIR)) + return ((options & FNM_CASEFOLD) + ? mbscasecmp (pattern, f) + : strcmp (pattern, f)); + else if (! (options & FNM_CASEFOLD)) + { + size_t patlen = strlen (pattern); + int r = strncmp (pattern, f, patlen); + if (! r) + { + r = f[patlen]; + if (r == '/') + r = 0; + } + return r; + } + else + { + /* Walk through a copy of F, seeing whether P matches any prefix + of F. + + FIXME: This is an O(N**2) algorithm; it should be O(N). + Also, the copy should not be necessary. However, fixing this + will probably involve a change to the mbs* API. */ + + char *fcopy = xstrdup (f); + char *p; + int r; + for (p = fcopy; ; *p++ = '/') + { + p = strchr (p, '/'); + if (p) + *p = '\0'; + r = mbscasecmp (pattern, fcopy); + if (!p || r <= 0) + break; + } + free (fcopy); + return r; + } +} + +bool +exclude_fnmatch (char const *pattern, char const *f, int options) +{ + int (*matcher) (char const *, char const *, int) = + (options & EXCLUDE_WILDCARDS + ? fnmatch + : fnmatch_no_wildcards); + bool matched = ((*matcher) (pattern, f, options) == 0); + char const *p; + + if (! (options & EXCLUDE_ANCHORED)) + for (p = f; *p && ! matched; p++) + if (*p == '/' && p[1] != '/') + matched = ((*matcher) (pattern, p + 1, options) == 0); + + return matched; +} + +/* Return true if the exclude_pattern segment SEG excludes F. */ + +static bool +excluded_file_pattern_p (struct exclude_segment const *seg, char const *f) +{ + size_t exclude_count = seg->v.pat.exclude_count; + struct patopts const *exclude = seg->v.pat.exclude; + size_t i; + bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE); + + /* Scan through the options, until they change excluded */ + for (i = 0; i < exclude_count; i++) + { + char const *pattern = exclude[i].pattern; + int options = exclude[i].options; + if (exclude_fnmatch (pattern, f, options)) + return !excluded; + } + return excluded; +} + +/* Return true if the exclude_hash segment SEG excludes F. + BUFFER is an auxiliary storage of the same length as F (with nul + terminator included) */ +static bool +excluded_file_name_p (struct exclude_segment const *seg, char const *f, + char *buffer) +{ + int options = seg->options; + bool excluded = !! (options & EXCLUDE_INCLUDE); + Hash_table *table = seg->v.table; + + do + { + /* initialize the pattern */ + strcpy (buffer, f); + + while (1) + { + if (hash_lookup (table, buffer)) + return !excluded; + if (options & FNM_LEADING_DIR) + { + char *p = strrchr (buffer, '/'); + if (p) + { + *p = 0; + continue; + } + } + break; + } + + if (!(options & EXCLUDE_ANCHORED)) + { + f = strchr (f, '/'); + if (f) + f++; + } + else + break; + } + while (f); + return excluded; +} + +/* Return true if EX excludes F. */ + +bool +excluded_file_name (struct exclude const *ex, char const *f) +{ + struct exclude_segment *seg; + bool excluded; + char *filename = NULL; + + /* If no patterns are given, the default is to include. */ + if (!ex->head) + return false; + + /* Otherwise, the default is the opposite of the first option. */ + excluded = !! (ex->head->options & EXCLUDE_INCLUDE); + /* Scan through the segments, seeing whether they change status from + excluded to included or vice versa. */ + for (seg = ex->head; seg; seg = seg->next) + { + bool rc; + + switch (seg->type) + { + case exclude_pattern: + rc = excluded_file_pattern_p (seg, f); + break; + + case exclude_hash: + if (!filename) + filename = xmalloc (strlen (f) + 1); + rc = excluded_file_name_p (seg, f, filename); + break; + + default: + abort (); + } + if (rc != excluded) + { + excluded = rc; + break; + } + } + free (filename); + return excluded; +} + +/* Append to EX the exclusion PATTERN with OPTIONS. */ + +void +add_exclude (struct exclude *ex, char const *pattern, int options) +{ + struct exclude_segment *seg; + + if ((options & EXCLUDE_WILDCARDS) + && fnmatch_pattern_has_wildcards (pattern, options)) + { + struct exclude_pattern *pat; + struct patopts *patopts; + + if (ex->tail && ex->tail->type == exclude_pattern + && ((ex->tail->options & EXCLUDE_INCLUDE) == + (options & EXCLUDE_INCLUDE))) + seg = ex->tail; + else + seg = new_exclude_segment (ex, exclude_pattern, options); + + pat = &seg->v.pat; + if (pat->exclude_count == pat->exclude_alloc) + pat->exclude = x2nrealloc (pat->exclude, &pat->exclude_alloc, + sizeof *pat->exclude); + patopts = &pat->exclude[pat->exclude_count++]; + patopts->pattern = pattern; + patopts->options = options; + } + else + { + char *str, *p; +#define EXCLUDE_HASH_FLAGS (EXCLUDE_INCLUDE|EXCLUDE_ANCHORED|\ + FNM_LEADING_DIR|FNM_CASEFOLD) + if (ex->tail && ex->tail->type == exclude_hash + && ((ex->tail->options & EXCLUDE_HASH_FLAGS) == + (options & EXCLUDE_HASH_FLAGS))) + seg = ex->tail; + else + seg = new_exclude_segment (ex, exclude_hash, options); + + str = xstrdup (pattern); + if (options & EXCLUDE_WILDCARDS) + unescape_pattern (str); + p = hash_insert (seg->v.table, str); + if (p != str) + free (str); + } +} + +/* Use ADD_FUNC to append to EX the patterns in FILE_NAME, each with + OPTIONS. LINE_END terminates each pattern in the file. If + LINE_END is a space character, ignore trailing spaces and empty + lines in FILE. Return -1 on failure, 0 on success. */ + +int +add_exclude_file (void (*add_func) (struct exclude *, char const *, int), + struct exclude *ex, char const *file_name, int options, + char line_end) +{ + bool use_stdin = file_name[0] == '-' && !file_name[1]; + FILE *in; + char *buf = NULL; + char *p; + char const *pattern; + char const *lim; + size_t buf_alloc = 0; + size_t buf_count = 0; + int c; + int e = 0; + + if (use_stdin) + in = stdin; + else if (! (in = fopen (file_name, "r"))) + return -1; + + while ((c = getc (in)) != EOF) + { + if (buf_count == buf_alloc) + buf = x2realloc (buf, &buf_alloc); + buf[buf_count++] = c; + } + + if (ferror (in)) + e = errno; + + if (!use_stdin && fclose (in) != 0) + e = errno; + + buf = xrealloc (buf, buf_count + 1); + buf[buf_count] = line_end; + lim = buf + buf_count + ! (buf_count == 0 || buf[buf_count - 1] == line_end); + pattern = buf; + + for (p = buf; p < lim; p++) + if (*p == line_end) + { + char *pattern_end = p; + + if (isspace ((unsigned char) line_end)) + { + for (; ; pattern_end--) + if (pattern_end == pattern) + goto next_pattern; + else if (! isspace ((unsigned char) pattern_end[-1])) + break; + } + + *pattern_end = '\0'; + (*add_func) (ex, pattern, options); + + next_pattern: + pattern = p + 1; + } + + errno = e; + return e ? -1 : 0; +} |