Code

pickaxe: plug regex leak
[git.git] / diffcore-pickaxe.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  * Copyright (C) 2010 Google Inc.
4  */
5 #include "cache.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "xdiff-interface.h"
9 #include "kwset.h"
11 struct diffgrep_cb {
12         regex_t *regexp;
13         int hit;
14 };
16 static void diffgrep_consume(void *priv, char *line, unsigned long len)
17 {
18         struct diffgrep_cb *data = priv;
19         regmatch_t regmatch;
20         int hold;
22         if (line[0] != '+' && line[0] != '-')
23                 return;
24         if (data->hit)
25                 /*
26                  * NEEDSWORK: we should have a way to terminate the
27                  * caller early.
28                  */
29                 return;
30         /* Yuck -- line ought to be "const char *"! */
31         hold = line[len];
32         line[len] = '\0';
33         data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
34         line[len] = hold;
35 }
37 static void fill_one(struct diff_filespec *one,
38                      mmfile_t *mf, struct userdiff_driver **textconv)
39 {
40         if (DIFF_FILE_VALID(one)) {
41                 *textconv = get_textconv(one);
42                 mf->size = fill_textconv(*textconv, one, &mf->ptr);
43         } else {
44                 memset(mf, 0, sizeof(*mf));
45         }
46 }
48 static int diff_grep(struct diff_filepair *p, regex_t *regexp, struct diff_options *o)
49 {
50         regmatch_t regmatch;
51         struct userdiff_driver *textconv_one = NULL;
52         struct userdiff_driver *textconv_two = NULL;
53         mmfile_t mf1, mf2;
54         int hit;
56         if (diff_unmodified_pair(p))
57                 return 0;
59         fill_one(p->one, &mf1, &textconv_one);
60         fill_one(p->two, &mf2, &textconv_two);
62         if (!mf1.ptr) {
63                 if (!mf2.ptr)
64                         return 0; /* ignore unmerged */
65                 /* created "two" -- does it have what we are looking for? */
66                 hit = !regexec(regexp, p->two->data, 1, &regmatch, 0);
67         } else if (!mf2.ptr) {
68                 /* removed "one" -- did it have what we are looking for? */
69                 hit = !regexec(regexp, p->one->data, 1, &regmatch, 0);
70         } else {
71                 /*
72                  * We have both sides; need to run textual diff and see if
73                  * the pattern appears on added/deleted lines.
74                  */
75                 struct diffgrep_cb ecbdata;
76                 xpparam_t xpp;
77                 xdemitconf_t xecfg;
79                 memset(&xpp, 0, sizeof(xpp));
80                 memset(&xecfg, 0, sizeof(xecfg));
81                 ecbdata.regexp = regexp;
82                 ecbdata.hit = 0;
83                 xecfg.ctxlen = o->context;
84                 xecfg.interhunkctxlen = o->interhunkcontext;
85                 xdi_diff_outf(&mf1, &mf2, diffgrep_consume, &ecbdata,
86                               &xpp, &xecfg);
87                 hit = ecbdata.hit;
88         }
89         if (textconv_one)
90                 free(mf1.ptr);
91         if (textconv_two)
92                 free(mf2.ptr);
93         return hit;
94 }
96 static void diffcore_pickaxe_grep(struct diff_options *o)
97 {
98         struct diff_queue_struct *q = &diff_queued_diff;
99         int i, err;
100         regex_t regex;
101         struct diff_queue_struct outq;
102         outq.queue = NULL;
103         outq.nr = outq.alloc = 0;
105         err = regcomp(&regex, o->pickaxe, REG_EXTENDED | REG_NEWLINE);
106         if (err) {
107                 char errbuf[1024];
108                 regerror(err, &regex, errbuf, 1024);
109                 regfree(&regex);
110                 die("invalid log-grep regex: %s", errbuf);
111         }
113         if (o->pickaxe_opts & DIFF_PICKAXE_ALL) {
114                 /* Showing the whole changeset if needle exists */
115                 for (i = 0; i < q->nr; i++) {
116                         struct diff_filepair *p = q->queue[i];
117                         if (diff_grep(p, &regex, o))
118                                 goto out; /* do not munge the queue */
119                 }
121                 /*
122                  * Otherwise we will clear the whole queue by copying
123                  * the empty outq at the end of this function, but
124                  * first clear the current entries in the queue.
125                  */
126                 for (i = 0; i < q->nr; i++)
127                         diff_free_filepair(q->queue[i]);
128         } else {
129                 /* Showing only the filepairs that has the needle */
130                 for (i = 0; i < q->nr; i++) {
131                         struct diff_filepair *p = q->queue[i];
132                         if (diff_grep(p, &regex, o))
133                                 diff_q(&outq, p);
134                         else
135                                 diff_free_filepair(p);
136                 }
137         }
139         free(q->queue);
140         *q = outq;
142  out:
143         regfree(&regex);
144         return;
147 static unsigned int contains(struct diff_filespec *one,
148                              const char *needle, unsigned long len,
149                              regex_t *regexp, kwset_t kws)
151         unsigned int cnt;
152         unsigned long sz;
153         const char *data;
154         if (!len)
155                 return 0;
156         if (diff_populate_filespec(one, 0))
157                 return 0;
159         sz = one->size;
160         data = one->data;
161         cnt = 0;
163         if (regexp) {
164                 regmatch_t regmatch;
165                 int flags = 0;
167                 assert(data[sz] == '\0');
168                 while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
169                         flags |= REG_NOTBOL;
170                         data += regmatch.rm_eo;
171                         if (*data && regmatch.rm_so == regmatch.rm_eo)
172                                 data++;
173                         cnt++;
174                 }
176         } else { /* Classic exact string match */
177                 while (sz) {
178                         size_t offset = kwsexec(kws, data, sz, NULL);
179                         const char *found;
180                         if (offset == -1)
181                                 break;
182                         else
183                                 found = data + offset;
184                         sz -= found - data + len;
185                         data = found + len;
186                         cnt++;
187                 }
188         }
189         diff_free_filespec_data(one);
190         return cnt;
193 static void diffcore_pickaxe_count(struct diff_options *o)
195         const char *needle = o->pickaxe;
196         int opts = o->pickaxe_opts;
197         struct diff_queue_struct *q = &diff_queued_diff;
198         unsigned long len = strlen(needle);
199         int i, has_changes;
200         regex_t regex, *regexp = NULL;
201         kwset_t kws = NULL;
202         struct diff_queue_struct outq;
203         DIFF_QUEUE_CLEAR(&outq);
205         if (opts & DIFF_PICKAXE_REGEX) {
206                 int err;
207                 err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
208                 if (err) {
209                         /* The POSIX.2 people are surely sick */
210                         char errbuf[1024];
211                         regerror(err, &regex, errbuf, 1024);
212                         regfree(&regex);
213                         die("invalid pickaxe regex: %s", errbuf);
214                 }
215                 regexp = &regex;
216         } else {
217                 kws = kwsalloc(NULL);
218                 kwsincr(kws, needle, len);
219                 kwsprep(kws);
220         }
222         if (opts & DIFF_PICKAXE_ALL) {
223                 /* Showing the whole changeset if needle exists */
224                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
225                         struct diff_filepair *p = q->queue[i];
226                         if (!DIFF_FILE_VALID(p->one)) {
227                                 if (!DIFF_FILE_VALID(p->two))
228                                         continue; /* ignore unmerged */
229                                 /* created */
230                                 if (contains(p->two, needle, len, regexp, kws))
231                                         has_changes++;
232                         }
233                         else if (!DIFF_FILE_VALID(p->two)) {
234                                 if (contains(p->one, needle, len, regexp, kws))
235                                         has_changes++;
236                         }
237                         else if (!diff_unmodified_pair(p) &&
238                                  contains(p->one, needle, len, regexp, kws) !=
239                                  contains(p->two, needle, len, regexp, kws))
240                                 has_changes++;
241                 }
242                 if (has_changes)
243                         return; /* not munge the queue */
245                 /* otherwise we will clear the whole queue
246                  * by copying the empty outq at the end of this
247                  * function, but first clear the current entries
248                  * in the queue.
249                  */
250                 for (i = 0; i < q->nr; i++)
251                         diff_free_filepair(q->queue[i]);
252         }
253         else
254                 /* Showing only the filepairs that has the needle */
255                 for (i = 0; i < q->nr; i++) {
256                         struct diff_filepair *p = q->queue[i];
257                         has_changes = 0;
258                         if (!DIFF_FILE_VALID(p->one)) {
259                                 if (!DIFF_FILE_VALID(p->two))
260                                         ; /* ignore unmerged */
261                                 /* created */
262                                 else if (contains(p->two, needle, len, regexp,
263                                                   kws))
264                                         has_changes = 1;
265                         }
266                         else if (!DIFF_FILE_VALID(p->two)) {
267                                 if (contains(p->one, needle, len, regexp, kws))
268                                         has_changes = 1;
269                         }
270                         else if (!diff_unmodified_pair(p) &&
271                                  contains(p->one, needle, len, regexp, kws) !=
272                                  contains(p->two, needle, len, regexp, kws))
273                                 has_changes = 1;
275                         if (has_changes)
276                                 diff_q(&outq, p);
277                         else
278                                 diff_free_filepair(p);
279                 }
281         if (opts & DIFF_PICKAXE_REGEX)
282                 regfree(&regex);
283         else
284                 kwsfree(kws);
286         free(q->queue);
287         *q = outq;
288         return;
291 void diffcore_pickaxe(struct diff_options *o)
293         /* Might want to warn when both S and G are on; I don't care... */
294         if (o->pickaxe_opts & DIFF_PICKAXE_KIND_G)
295                 diffcore_pickaxe_grep(o);
296         else
297                 diffcore_pickaxe_count(o);