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"
  10
  11 typedef int (*pickaxe_fn)(struct diff_filepair *p, struct diff_options *o, regex_t *regexp, kwset_t kws);
  12
  13 static void pickaxe(struct diff_queue_struct *q, struct diff_options *o,
  14                     regex_t *regexp, kwset_t kws, pickaxe_fn fn)
  15 {
  16         int i;
  17         struct diff_queue_struct outq;
  18
  19         DIFF_QUEUE_CLEAR(&outq);
  20
  21         if (o->pickaxe_opts & DIFF_PICKAXE_ALL) {
  22                 /* Showing the whole changeset if needle exists */
  23                 for (i = 0; i < q->nr; i++) {
  24                         struct diff_filepair *p = q->queue[i];
  25                         if (fn(p, o, regexp, kws))
  26                                 return; /* do not munge the queue */
  27                 }
  28
  29                 /*
  30                  * Otherwise we will clear the whole queue by copying
  31                  * the empty outq at the end of this function, but
  32                  * first clear the current entries in the queue.
  33                  */
  34                 for (i = 0; i < q->nr; i++)
  35                         diff_free_filepair(q->queue[i]);
  36         } else {
  37                 /* Showing only the filepairs that has the needle */
  38                 for (i = 0; i < q->nr; i++) {
  39                         struct diff_filepair *p = q->queue[i];
  40                         if (fn(p, o, regexp, kws))
  41                                 diff_q(&outq, p);
  42                         else
  43                                 diff_free_filepair(p);
  44                 }
  45         }
  46
  47         free(q->queue);
  48         *q = outq;
  49 }
  50
  51 struct diffgrep_cb {
  52         regex_t *regexp;
  53         int hit;
  54 };
  55
  56 static void diffgrep_consume(void *priv, char *line, unsigned long len)
  57 {
  58         struct diffgrep_cb *data = priv;
  59         regmatch_t regmatch;
  60         int hold;
  61
  62         if (line[0] != '+' && line[0] != '-')
  63                 return;
  64         if (data->hit)
  65                 /*
  66                  * NEEDSWORK: we should have a way to terminate the
  67                  * caller early.
  68                  */
  69                 return;
  70         /* Yuck -- line ought to be "const char *"! */
  71         hold = line[len];
  72         line[len] = '\0';
  73         data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
  74         line[len] = hold;
  75 }
  76
  77 static void fill_one(struct diff_filespec *one,
  78                      mmfile_t *mf, struct userdiff_driver **textconv)
  79 {
  80         if (DIFF_FILE_VALID(one)) {
  81                 *textconv = get_textconv(one);
  82                 mf->size = fill_textconv(*textconv, one, &mf->ptr);
  83         } else {
  84                 memset(mf, 0, sizeof(*mf));
  85         }
  86 }
  87
  88 static int diff_grep(struct diff_filepair *p, struct diff_options *o,
  89                      regex_t *regexp, kwset_t kws)
  90 {
  91         regmatch_t regmatch;
  92         struct userdiff_driver *textconv_one = NULL;
  93         struct userdiff_driver *textconv_two = NULL;
  94         mmfile_t mf1, mf2;
  95         int hit;
  96
  97         if (diff_unmodified_pair(p))
  98                 return 0;
  99
 100         fill_one(p->one, &mf1, &textconv_one);
 101         fill_one(p->two, &mf2, &textconv_two);
 102
 103         if (!mf1.ptr) {
 104                 if (!mf2.ptr)
 105                         return 0; /* ignore unmerged */
 106                 /* created "two" -- does it have what we are looking for? */
 107                 hit = !regexec(regexp, mf2.ptr, 1, &regmatch, 0);
 108         } else if (!mf2.ptr) {
 109                 /* removed "one" -- did it have what we are looking for? */
 110                 hit = !regexec(regexp, mf1.ptr, 1, &regmatch, 0);
 111         } else {
 112                 /*
 113                  * We have both sides; need to run textual diff and see if
 114                  * the pattern appears on added/deleted lines.
 115                  */
 116                 struct diffgrep_cb ecbdata;
 117                 xpparam_t xpp;
 118                 xdemitconf_t xecfg;
 119
 120                 memset(&xpp, 0, sizeof(xpp));
 121                 memset(&xecfg, 0, sizeof(xecfg));
 122                 ecbdata.regexp = regexp;
 123                 ecbdata.hit = 0;
 124                 xecfg.ctxlen = o->context;
 125                 xecfg.interhunkctxlen = o->interhunkcontext;
 126                 xdi_diff_outf(&mf1, &mf2, diffgrep_consume, &ecbdata,
 127                               &xpp, &xecfg);
 128                 hit = ecbdata.hit;
 129         }
 130         if (textconv_one)
 131                 free(mf1.ptr);
 132         if (textconv_two)
 133                 free(mf2.ptr);
 134         return hit;
 135 }
 136
 137 static void diffcore_pickaxe_grep(struct diff_options *o)
 138 {
 139         int err;
 140         regex_t regex;
 141         int cflags = REG_EXTENDED | REG_NEWLINE;
 142
 143         if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE))
 144                 cflags |= REG_ICASE;
 145
 146         err = regcomp(&regex, o->pickaxe, cflags);
 147         if (err) {
 148                 char errbuf[1024];
 149                 regerror(err, &regex, errbuf, 1024);
 150                 regfree(&regex);
 151                 die("invalid log-grep regex: %s", errbuf);
 152         }
 153
 154         pickaxe(&diff_queued_diff, o, &regex, NULL, diff_grep);
 155
 156         regfree(&regex);
 157         return;
 158 }
 159
 160 static unsigned int contains(mmfile_t *mf, struct diff_options *o,
 161                              regex_t *regexp, kwset_t kws)
 162 {
 163         unsigned int cnt;
 164         unsigned long sz;
 165         const char *data;
 166
 167         sz = mf->size;
 168         data = mf->ptr;
 169         cnt = 0;
 170
 171         if (regexp) {
 172                 regmatch_t regmatch;
 173                 int flags = 0;
 174
 175                 assert(data[sz] == '\0');
 176                 while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
 177                         flags |= REG_NOTBOL;
 178                         data += regmatch.rm_eo;
 179                         if (*data && regmatch.rm_so == regmatch.rm_eo)
 180                                 data++;
 181                         cnt++;
 182                 }
 183
 184         } else { /* Classic exact string match */
 185                 while (sz) {
 186                         struct kwsmatch kwsm;
 187                         size_t offset = kwsexec(kws, data, sz, &kwsm);
 188                         const char *found;
 189                         if (offset == -1)
 190                                 break;
 191                         else
 192                                 found = data + offset;
 193                         sz -= found - data + kwsm.size[0];
 194                         data = found + kwsm.size[0];
 195                         cnt++;
 196                 }
 197         }
 198         return cnt;
 199 }
 200
 201 static int has_changes(struct diff_filepair *p, struct diff_options *o,
 202                        regex_t *regexp, kwset_t kws)
 203 {
 204         struct userdiff_driver *textconv_one = get_textconv(p->one);
 205         struct userdiff_driver *textconv_two = get_textconv(p->two);
 206         mmfile_t mf1, mf2;
 207         int ret;
 208
 209         if (!o->pickaxe[0])
 210                 return 0;
 211
 212         /*
 213          * If we have an unmodified pair, we know that the count will be the
 214          * same and don't even have to load the blobs. Unless textconv is in
 215          * play, _and_ we are using two different textconv filters (e.g.,
 216          * because a pair is an exact rename with different textconv attributes
 217          * for each side, which might generate different content).
 218          */
 219         if (textconv_one == textconv_two && diff_unmodified_pair(p))
 220                 return 0;
 221
 222         fill_one(p->one, &mf1, &textconv_one);
 223         fill_one(p->two, &mf2, &textconv_two);
 224
 225         if (!mf1.ptr) {
 226                 if (!mf2.ptr)
 227                         ret = 0; /* ignore unmerged */
 228                 /* created */
 229                 ret = contains(&mf2, o, regexp, kws) != 0;
 230         }
 231         else if (!mf2.ptr) /* removed */
 232                 ret = contains(&mf1, o, regexp, kws) != 0;
 233         else
 234                 ret = contains(&mf1, o, regexp, kws) !=
 235                       contains(&mf2, o, regexp, kws);
 236
 237         if (textconv_one)
 238                 free(mf1.ptr);
 239         if (textconv_two)
 240                 free(mf2.ptr);
 241         diff_free_filespec_data(p->one);
 242         diff_free_filespec_data(p->two);
 243
 244         return ret;
 245 }
 246
 247 static void diffcore_pickaxe_count(struct diff_options *o)
 248 {
 249         const char *needle = o->pickaxe;
 250         int opts = o->pickaxe_opts;
 251         unsigned long len = strlen(needle);
 252         regex_t regex, *regexp = NULL;
 253         kwset_t kws = NULL;
 254
 255         if (opts & DIFF_PICKAXE_REGEX) {
 256                 int err;
 257                 err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
 258                 if (err) {
 259                         /* The POSIX.2 people are surely sick */
 260                         char errbuf[1024];
 261                         regerror(err, &regex, errbuf, 1024);
 262                         regfree(&regex);
 263                         die("invalid pickaxe regex: %s", errbuf);
 264                 }
 265                 regexp = &regex;
 266         } else {
 267                 kws = kwsalloc(DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE)
 268                                ? tolower_trans_tbl : NULL);
 269                 kwsincr(kws, needle, len);
 270                 kwsprep(kws);
 271         }
 272
 273         pickaxe(&diff_queued_diff, o, regexp, kws, has_changes);
 274
 275         if (opts & DIFF_PICKAXE_REGEX)
 276                 regfree(&regex);
 277         else
 278                 kwsfree(kws);
 279         return;
 280 }
 281
 282 void diffcore_pickaxe(struct diff_options *o)
 283 {
 284         /* Might want to warn when both S and G are on; I don't care... */
 285         if (o->pickaxe_opts & DIFF_PICKAXE_KIND_G)
 286                 diffcore_pickaxe_grep(o);
 287         else
 288                 diffcore_pickaxe_count(o);
 289 }