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1 #define DISABLE_SIGN_COMPARE_WARNINGS
2
3 #include "git-compat-util.h"
4 #include "environment.h"
5 #include "gettext.h"
6 #include "config.h"
7 #include "hex.h"
8 #include "odb.h"
9 #include "strbuf.h"
10 #include "xdiff-interface.h"
11 #include "xdiff/xtypes.h"
12 #include "xdiff/xdiffi.h"
13 #include "xdiff/xutils.h"
14
15 struct xdiff_emit_state {
16 xdiff_emit_hunk_fn hunk_fn;
17 xdiff_emit_line_fn line_fn;
18 void *consume_callback_data;
19 struct strbuf remainder;
20 };
21
22 static int xdiff_out_hunk(void *priv_,
23 long old_begin, long old_nr,
24 long new_begin, long new_nr,
25 const char *func, long funclen)
26 {
27 struct xdiff_emit_state *priv = priv_;
28
29 if (priv->remainder.len)
30 BUG("xdiff emitted hunk in the middle of a line");
31
32 priv->hunk_fn(priv->consume_callback_data,
33 old_begin, old_nr, new_begin, new_nr,
34 func, funclen);
35 return 0;
36 }
37
38 static int consume_one(void *priv_, char *s, unsigned long size)
39 {
40 struct xdiff_emit_state *priv = priv_;
41 char *ep;
42 while (size) {
43 unsigned long this_size;
44 int ret;
45 ep = memchr(s, '\n', size);
46 this_size = (ep == NULL) ? size : (ep - s + 1);
47 ret = priv->line_fn(priv->consume_callback_data, s, this_size);
48 if (ret)
49 return ret;
50 size -= this_size;
51 s += this_size;
52 }
53 return 0;
54 }
55
56 static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
57 {
58 struct xdiff_emit_state *priv = priv_;
59 int i;
60 int stop = 0;
61
62 if (!priv->line_fn)
63 return 0;
64
65 for (i = 0; i < nbuf; i++) {
66 if (stop)
67 return 1;
68 if (mb[i].ptr[mb[i].size-1] != '\n') {
69 /* Incomplete line */
70 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
71 continue;
72 }
73
74 /* we have a complete line */
75 if (!priv->remainder.len) {
76 stop = consume_one(priv, mb[i].ptr, mb[i].size);
77 continue;
78 }
79 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
80 stop = consume_one(priv, priv->remainder.buf, priv->remainder.len);
81 strbuf_reset(&priv->remainder);
82 }
83 if (stop)
84 return -1;
85 if (priv->remainder.len) {
86 stop = consume_one(priv, priv->remainder.buf, priv->remainder.len);
87 strbuf_reset(&priv->remainder);
88 }
89 if (stop)
90 return -1;
91 return 0;
92 }
93
94 static int strbuf_out_line(void *priv, mmbuffer_t *mb, int nbuf)
95 {
96 struct strbuf *out = priv;
97 int i;
98 for (i = 0; i < nbuf; i++)
99 strbuf_add(out, mb[i].ptr, mb[i].size);
100 return 0;
101 }
102
103 void xdiff_emit_hunk_header(struct strbuf *out,
104 long old_begin, long old_count,
105 long new_begin, long new_count,
106 const char *func, long funclen)
107 {
108 xdemitcb_t ecb = { .priv = out, .out_line = strbuf_out_line };
109 xdl_emit_hunk_hdr(old_begin, old_count, new_begin, new_count,
110 func, funclen, &ecb);
111 }
112
113 /*
114 * Trim down common substring at the end of the buffers,
115 * but end on a complete line.
116 */
117 static void trim_common_tail(mmfile_t *a, mmfile_t *b)
118 {
119 const int blk = 1024;
120 long trimmed = 0, recovered = 0;
121 char *ap = a->size ? a->ptr + a->size : a->ptr;
122 char *bp = b->size ? b->ptr + b->size : b->ptr;
123 long smaller = (a->size < b->size) ? a->size : b->size;
124
125 while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
126 trimmed += blk;
127 ap -= blk;
128 bp -= blk;
129 }
130
131 while (recovered < trimmed)
132 if (ap[recovered++] == '\n')
133 break;
134 a->size -= trimmed - recovered;
135 b->size -= trimmed - recovered;
136 }
137
138 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
139 {
140 mmfile_t a = *mf1;
141 mmfile_t b = *mf2;
142
143 if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
144 return -1;
145
146 if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
147 trim_common_tail(&a, &b);
148
149 return xdl_diff(&a, &b, xpp, xecfg, xecb);
150 }
151
152 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
153 xdiff_emit_hunk_fn hunk_fn,
154 xdiff_emit_line_fn line_fn,
155 void *consume_callback_data,
156 xpparam_t const *xpp, xdemitconf_t const *xecfg)
157 {
158 int ret;
159 struct xdiff_emit_state state;
160 xdemitcb_t ecb;
161
162 memset(&state, 0, sizeof(state));
163 state.hunk_fn = hunk_fn;
164 state.line_fn = line_fn;
165 state.consume_callback_data = consume_callback_data;
166 memset(&ecb, 0, sizeof(ecb));
167 if (hunk_fn)
168 ecb.out_hunk = xdiff_out_hunk;
169 ecb.out_line = xdiff_outf;
170 ecb.priv = &state;
171 strbuf_init(&state.remainder, 0);
172 ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
173 strbuf_release(&state.remainder);
174 return ret;
175 }
176
177 int read_mmfile(mmfile_t *ptr, const char *filename)
178 {
179 struct stat st;
180 FILE *f;
181 size_t sz;
182
183 if (stat(filename, &st))
184 return error_errno("Could not stat %s", filename);
185 if (!(f = fopen(filename, "rb")))
186 return error_errno("Could not open %s", filename);
187 sz = xsize_t(st.st_size);
188 ptr->ptr = xmalloc(sz ? sz : 1);
189 if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
190 fclose(f);
191 return error("Could not read %s", filename);
192 }
193 fclose(f);
194 ptr->size = sz;
195 return 0;
196 }
197
198 void read_mmblob(mmfile_t *ptr, struct object_database *odb,
199 const struct object_id *oid)
200 {
201 size_t size;
202 enum object_type type;
203
204 if (is_null_oid(oid)) {
205 ptr->ptr = xstrdup("");
206 ptr->size = 0;
207 return;
208 }
209
210 ptr->ptr = odb_read_object(odb, oid, &type, &size);
211 if (!ptr->ptr || type != OBJ_BLOB)
212 die("unable to read blob object %s", oid_to_hex(oid));
213 ptr->size = size;
214 }
215
216 #define FIRST_FEW_BYTES 8000
217 int buffer_is_binary(const char *ptr, unsigned long size)
218 {
219 if (FIRST_FEW_BYTES < size)
220 size = FIRST_FEW_BYTES;
221 return !!memchr(ptr, 0, size);
222 }
223
224 struct ff_regs {
225 int nr;
226 struct ff_reg {
227 regex_t re;
228 int negate;
229 } *array;
230 };
231
232 static long ff_regexp(const char *line, long len,
233 char *buffer, long buffer_size, void *priv)
234 {
235 struct ff_regs *regs = priv;
236 regmatch_t pmatch[2];
237 int i;
238 int result;
239
240 /* Exclude terminating newline (and cr) from matching */
241 if (len > 0 && line[len-1] == '\n') {
242 if (len > 1 && line[len-2] == '\r')
243 len -= 2;
244 else
245 len--;
246 }
247
248 for (i = 0; i < regs->nr; i++) {
249 struct ff_reg *reg = regs->array + i;
250 if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
251 if (reg->negate)
252 return -1;
253 break;
254 }
255 }
256 if (regs->nr <= i)
257 return -1;
258 i = pmatch[1].rm_so >= 0 ? 1 : 0;
259 line += pmatch[i].rm_so;
260 result = pmatch[i].rm_eo - pmatch[i].rm_so;
261 if (result > buffer_size)
262 result = buffer_size;
263 while (result > 0 && (isspace(line[result - 1])))
264 result--;
265 memcpy(buffer, line, result);
266 return result;
267 }
268
269 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
270 {
271 int i;
272 struct ff_regs *regs;
273
274 xecfg->find_func = ff_regexp;
275 regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
276 for (i = 0, regs->nr = 1; value[i]; i++)
277 if (value[i] == '\n')
278 regs->nr++;
279 ALLOC_ARRAY(regs->array, regs->nr);
280 for (i = 0; i < regs->nr; i++) {
281 struct ff_reg *reg = regs->array + i;
282 const char *ep, *expression;
283 char *buffer = NULL;
284
285 if (!value)
286 BUG("mismatch between line count and parsing");
287 ep = strchr(value, '\n');
288
289 reg->negate = (*value == '!');
290 if (reg->negate && i == regs->nr - 1)
291 die("Last expression must not be negated: %s", value);
292 if (*value == '!')
293 value++;
294 if (ep)
295 expression = buffer = xstrndup(value, ep - value);
296 else
297 expression = value;
298 if (regcomp(&reg->re, expression, cflags))
299 die("Invalid regexp to look for hunk header: %s", expression);
300 free(buffer);
301 value = ep ? ep + 1 : NULL;
302 }
303 }
304
305 void xdiff_clear_find_func(xdemitconf_t *xecfg)
306 {
307 if (xecfg->find_func) {
308 int i;
309 struct ff_regs *regs = xecfg->find_func_priv;
310
311 for (i = 0; i < regs->nr; i++)
312 regfree(&regs->array[i].re);
313 free(regs->array);
314 free(regs);
315 xecfg->find_func = NULL;
316 xecfg->find_func_priv = NULL;
317 }
318 }
319
320 unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
321 {
322 return xdl_hash_record((uint8_t const**)&s, (uint8_t const*)s + len, flags);
323 }
324
325 int xdiff_compare_lines(const char *l1, long s1,
326 const char *l2, long s2, long flags)
327 {
328 return xdl_recmatch(l1, s1, l2, s2, flags);
329 }
330
331 int parse_conflict_style_name(const char *value)
332 {
333 if (!strcmp(value, "diff3"))
334 return XDL_MERGE_DIFF3;
335 else if (!strcmp(value, "zdiff3"))
336 return XDL_MERGE_ZEALOUS_DIFF3;
337 else if (!strcmp(value, "merge"))
338 return 0;
339 /*
340 * Please update _git_checkout() in git-completion.bash when
341 * you add new merge config
342 */
343 else
344 return -1;
345 }
346
347 const char *conflict_style_name(int style)
348 {
349 switch (style) {
350 case XDL_MERGE_DIFF3:
351 return "diff3";
352 case XDL_MERGE_ZEALOUS_DIFF3:
353 return "zdiff3";
354 default:
355 return "merge";
356 }
357 }
358
359 int git_xmerge_style = -1;
360
361 int git_xmerge_config(const char *var, const char *value,
362 const struct config_context *ctx, void *cb)
363 {
364 if (!strcmp(var, "merge.conflictstyle")) {
365 if (!value)
366 return config_error_nonbool(var);
367 git_xmerge_style = parse_conflict_style_name(value);
368 if (git_xmerge_style == -1)
369 return error(_("unknown style '%s' given for '%s'"),
370 value, var);
371 return 0;
372 }
373 return git_default_config(var, value, ctx, cb);
374 }