react to errors in xdi_diff
[git/git.git] / xdiff-interface.c
CommitLineData
d9ea73e0
JH
1#include "cache.h"
2#include "xdiff-interface.h"
86295bb6
RS
3#include "xdiff/xtypes.h"
4#include "xdiff/xdiffi.h"
5#include "xdiff/xemit.h"
6#include "xdiff/xmacros.h"
8a3f524b
JH
7
8struct xdiff_emit_state {
9 xdiff_emit_consume_fn consume;
10 void *consume_callback_data;
11 struct strbuf remainder;
12};
d9ea73e0 13
a0fd3146 14static int parse_num(char **cp_p, int *num_p)
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JH
15{
16 char *cp = *cp_p;
a0fd3146 17 int num = 0;
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JH
18
19 while ('0' <= *cp && *cp <= '9')
20 num = num * 10 + *cp++ - '0';
eb3a9dd3 21 if (!(cp - *cp_p))
c1e335a4
JH
22 return -1;
23 *cp_p = cp;
24 *num_p = num;
25 return 0;
26}
27
28int parse_hunk_header(char *line, int len,
a0fd3146
JH
29 int *ob, int *on,
30 int *nb, int *nn)
c1e335a4
JH
31{
32 char *cp;
33 cp = line + 4;
34 if (parse_num(&cp, ob)) {
35 bad_line:
36 return error("malformed diff output: %s", line);
37 }
38 if (*cp == ',') {
39 cp++;
40 if (parse_num(&cp, on))
41 goto bad_line;
42 }
43 else
44 *on = 1;
45 if (*cp++ != ' ' || *cp++ != '+')
46 goto bad_line;
47 if (parse_num(&cp, nb))
48 goto bad_line;
49 if (*cp == ',') {
50 cp++;
51 if (parse_num(&cp, nn))
52 goto bad_line;
53 }
54 else
55 *nn = 1;
56 return -!!memcmp(cp, " @@", 3);
57}
58
d9ea73e0
JH
59static void consume_one(void *priv_, char *s, unsigned long size)
60{
61 struct xdiff_emit_state *priv = priv_;
62 char *ep;
63 while (size) {
64 unsigned long this_size;
65 ep = memchr(s, '\n', size);
66 this_size = (ep == NULL) ? size : (ep - s + 1);
8a3f524b 67 priv->consume(priv->consume_callback_data, s, this_size);
d9ea73e0
JH
68 size -= this_size;
69 s += this_size;
70 }
71}
72
c99db9d2 73static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
d9ea73e0
JH
74{
75 struct xdiff_emit_state *priv = priv_;
76 int i;
77
78 for (i = 0; i < nbuf; i++) {
79 if (mb[i].ptr[mb[i].size-1] != '\n') {
80 /* Incomplete line */
b4637760 81 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
d9ea73e0
JH
82 continue;
83 }
84
85 /* we have a complete line */
b4637760 86 if (!priv->remainder.len) {
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JH
87 consume_one(priv, mb[i].ptr, mb[i].size);
88 continue;
89 }
b4637760
BD
90 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
91 consume_one(priv, priv->remainder.buf, priv->remainder.len);
92 strbuf_reset(&priv->remainder);
d9ea73e0 93 }
b4637760
BD
94 if (priv->remainder.len) {
95 consume_one(priv, priv->remainder.buf, priv->remainder.len);
96 strbuf_reset(&priv->remainder);
d9ea73e0
JH
97 }
98 return 0;
99}
7cab5883 100
913b45f5
JH
101/*
102 * Trim down common substring at the end of the buffers,
103 * but leave at least ctx lines at the end.
104 */
29ab27f4 105static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
913b45f5
JH
106{
107 const int blk = 1024;
52499977 108 long trimmed = 0, recovered = 0;
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JH
109 char *ap = a->ptr + a->size;
110 char *bp = b->ptr + b->size;
111 long smaller = (a->size < b->size) ? a->size : b->size;
112
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LT
113 if (ctx)
114 return;
115
913b45f5
JH
116 while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
117 trimmed += blk;
118 ap -= blk;
119 bp -= blk;
120 }
121
d2f82950 122 while (recovered < trimmed)
52499977 123 if (ap[recovered++] == '\n')
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LT
124 break;
125 a->size -= trimmed - recovered;
126 b->size -= trimmed - recovered;
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JH
127}
128
c279d7e9
JH
129int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
130{
913b45f5
JH
131 mmfile_t a = *mf1;
132 mmfile_t b = *mf2;
133
134 trim_common_tail(&a, &b, xecfg->ctxlen);
135
136 return xdl_diff(&a, &b, xpp, xecfg, xecb);
c279d7e9
JH
137}
138
c99db9d2 139int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
8a3f524b 140 xdiff_emit_consume_fn fn, void *consume_callback_data,
dfea7900 141 xpparam_t const *xpp, xdemitconf_t const *xecfg)
c99db9d2
BD
142{
143 int ret;
8a3f524b 144 struct xdiff_emit_state state;
dfea7900 145 xdemitcb_t ecb;
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JH
146
147 memset(&state, 0, sizeof(state));
148 state.consume = fn;
149 state.consume_callback_data = consume_callback_data;
dfea7900
RS
150 memset(&ecb, 0, sizeof(ecb));
151 ecb.outf = xdiff_outf;
152 ecb.priv = &state;
8a3f524b 153 strbuf_init(&state.remainder, 0);
dfea7900 154 ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
8a3f524b 155 strbuf_release(&state.remainder);
c99db9d2
BD
156 return ret;
157}
158
7cab5883
JS
159int read_mmfile(mmfile_t *ptr, const char *filename)
160{
161 struct stat st;
162 FILE *f;
dc49cd76 163 size_t sz;
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JS
164
165 if (stat(filename, &st))
166 return error("Could not stat %s", filename);
167 if ((f = fopen(filename, "rb")) == NULL)
168 return error("Could not open %s", filename);
dc49cd76 169 sz = xsize_t(st.st_size);
381b851c 170 ptr->ptr = xmalloc(sz ? sz : 1);
5fd89814
RS
171 if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
172 fclose(f);
7cab5883 173 return error("Could not read %s", filename);
5fd89814 174 }
7cab5883 175 fclose(f);
dc49cd76 176 ptr->size = sz;
7cab5883
JS
177 return 0;
178}
179
06b65939
ML
180void read_mmblob(mmfile_t *ptr, const unsigned char *sha1)
181{
182 unsigned long size;
183 enum object_type type;
184
185 if (!hashcmp(sha1, null_sha1)) {
186 ptr->ptr = xstrdup("");
187 ptr->size = 0;
188 return;
189 }
190
191 ptr->ptr = read_sha1_file(sha1, &type, &size);
192 if (!ptr->ptr || type != OBJ_BLOB)
193 die("unable to read blob object %s", sha1_to_hex(sha1));
194 ptr->size = size;
195}
196
6bfce93e
JS
197#define FIRST_FEW_BYTES 8000
198int buffer_is_binary(const char *ptr, unsigned long size)
199{
200 if (FIRST_FEW_BYTES < size)
201 size = FIRST_FEW_BYTES;
202 return !!memchr(ptr, 0, size);
203}
f258475a
JH
204
205struct ff_regs {
206 int nr;
207 struct ff_reg {
208 regex_t re;
209 int negate;
210 } *array;
211};
212
213static long ff_regexp(const char *line, long len,
214 char *buffer, long buffer_size, void *priv)
215{
a5a5a048 216 char *line_buffer;
f258475a
JH
217 struct ff_regs *regs = priv;
218 regmatch_t pmatch[2];
3d8dccd7
JH
219 int i;
220 int result = -1;
f258475a 221
a5a5a048
BC
222 /* Exclude terminating newline (and cr) from matching */
223 if (len > 0 && line[len-1] == '\n') {
46dc1b0e
JH
224 if (len > 1 && line[len-2] == '\r')
225 len -= 2;
226 else
227 len--;
228 }
229
230 line_buffer = xstrndup(line, len); /* make NUL terminated */
f258475a
JH
231
232 for (i = 0; i < regs->nr; i++) {
233 struct ff_reg *reg = regs->array + i;
3d8dccd7
JH
234 if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
235 if (reg->negate)
236 goto fail;
237 break;
f258475a
JH
238 }
239 }
3d8dccd7
JH
240 if (regs->nr <= i)
241 goto fail;
f258475a
JH
242 i = pmatch[1].rm_so >= 0 ? 1 : 0;
243 line += pmatch[i].rm_so;
244 result = pmatch[i].rm_eo - pmatch[i].rm_so;
245 if (result > buffer_size)
246 result = buffer_size;
1b6ecbad
BC
247 while (result > 0 && (isspace(line[result - 1])))
248 result--;
f258475a 249 memcpy(buffer, line, result);
3d8dccd7 250 fail:
f258475a
JH
251 free(line_buffer);
252 return result;
253}
254
a013585b 255void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
f258475a
JH
256{
257 int i;
258 struct ff_regs *regs;
259
260 xecfg->find_func = ff_regexp;
261 regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
262 for (i = 0, regs->nr = 1; value[i]; i++)
263 if (value[i] == '\n')
264 regs->nr++;
265 regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
266 for (i = 0; i < regs->nr; i++) {
267 struct ff_reg *reg = regs->array + i;
268 const char *ep = strchr(value, '\n'), *expression;
269 char *buffer = NULL;
270
271 reg->negate = (*value == '!');
272 if (reg->negate && i == regs->nr - 1)
273 die("Last expression must not be negated: %s", value);
274 if (*value == '!')
275 value++;
276 if (ep)
277 expression = buffer = xstrndup(value, ep - value);
278 else
279 expression = value;
a013585b 280 if (regcomp(&reg->re, expression, cflags))
f258475a 281 die("Invalid regexp to look for hunk header: %s", expression);
8e0f7003 282 free(buffer);
f258475a
JH
283 value = ep + 1;
284 }
285}
b5412484 286
8cfe5f1c
RS
287void xdiff_clear_find_func(xdemitconf_t *xecfg)
288{
289 if (xecfg->find_func) {
290 int i;
291 struct ff_regs *regs = xecfg->find_func_priv;
292
293 for (i = 0; i < regs->nr; i++)
294 regfree(&regs->array[i].re);
295 free(regs->array);
296 free(regs);
297 xecfg->find_func = NULL;
298 xecfg->find_func_priv = NULL;
299 }
300}
301
b5412484
JH
302int git_xmerge_style = -1;
303
304int git_xmerge_config(const char *var, const char *value, void *cb)
305{
8c2be75f 306 if (!strcmp(var, "merge.conflictstyle")) {
b5412484
JH
307 if (!value)
308 die("'%s' is not a boolean", var);
309 if (!strcmp(value, "diff3"))
310 git_xmerge_style = XDL_MERGE_DIFF3;
311 else if (!strcmp(value, "merge"))
312 git_xmerge_style = 0;
313 else
314 die("unknown style '%s' given for '%s'",
315 value, var);
316 return 0;
317 }
318 return git_default_config(var, value, cb);
319}