Merge branch 'bc/master-diff-hunk-header-fix'
[git/git.git] / xdiff-interface.c
1 #include "cache.h"
2 #include "xdiff-interface.h"
3 #include "strbuf.h"
4
5 struct xdiff_emit_state {
6 xdiff_emit_consume_fn consume;
7 void *consume_callback_data;
8 struct strbuf remainder;
9 };
10
11 static int parse_num(char **cp_p, int *num_p)
12 {
13 char *cp = *cp_p;
14 int num = 0;
15 int read_some;
16
17 while ('0' <= *cp && *cp <= '9')
18 num = num * 10 + *cp++ - '0';
19 if (!(read_some = cp - *cp_p))
20 return -1;
21 *cp_p = cp;
22 *num_p = num;
23 return 0;
24 }
25
26 int parse_hunk_header(char *line, int len,
27 int *ob, int *on,
28 int *nb, int *nn)
29 {
30 char *cp;
31 cp = line + 4;
32 if (parse_num(&cp, ob)) {
33 bad_line:
34 return error("malformed diff output: %s", line);
35 }
36 if (*cp == ',') {
37 cp++;
38 if (parse_num(&cp, on))
39 goto bad_line;
40 }
41 else
42 *on = 1;
43 if (*cp++ != ' ' || *cp++ != '+')
44 goto bad_line;
45 if (parse_num(&cp, nb))
46 goto bad_line;
47 if (*cp == ',') {
48 cp++;
49 if (parse_num(&cp, nn))
50 goto bad_line;
51 }
52 else
53 *nn = 1;
54 return -!!memcmp(cp, " @@", 3);
55 }
56
57 static void consume_one(void *priv_, char *s, unsigned long size)
58 {
59 struct xdiff_emit_state *priv = priv_;
60 char *ep;
61 while (size) {
62 unsigned long this_size;
63 ep = memchr(s, '\n', size);
64 this_size = (ep == NULL) ? size : (ep - s + 1);
65 priv->consume(priv->consume_callback_data, s, this_size);
66 size -= this_size;
67 s += this_size;
68 }
69 }
70
71 static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
72 {
73 struct xdiff_emit_state *priv = priv_;
74 int i;
75
76 for (i = 0; i < nbuf; i++) {
77 if (mb[i].ptr[mb[i].size-1] != '\n') {
78 /* Incomplete line */
79 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
80 continue;
81 }
82
83 /* we have a complete line */
84 if (!priv->remainder.len) {
85 consume_one(priv, mb[i].ptr, mb[i].size);
86 continue;
87 }
88 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
89 consume_one(priv, priv->remainder.buf, priv->remainder.len);
90 strbuf_reset(&priv->remainder);
91 }
92 if (priv->remainder.len) {
93 consume_one(priv, priv->remainder.buf, priv->remainder.len);
94 strbuf_reset(&priv->remainder);
95 }
96 return 0;
97 }
98
99 /*
100 * Trim down common substring at the end of the buffers,
101 * but leave at least ctx lines at the end.
102 */
103 static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
104 {
105 const int blk = 1024;
106 long trimmed = 0, recovered = 0;
107 char *ap = a->ptr + a->size;
108 char *bp = b->ptr + b->size;
109 long smaller = (a->size < b->size) ? a->size : b->size;
110
111 if (ctx)
112 return;
113
114 while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
115 trimmed += blk;
116 ap -= blk;
117 bp -= blk;
118 }
119
120 while (recovered < trimmed)
121 if (ap[recovered++] == '\n')
122 break;
123 a->size -= trimmed - recovered;
124 b->size -= trimmed - recovered;
125 }
126
127 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
128 {
129 mmfile_t a = *mf1;
130 mmfile_t b = *mf2;
131
132 trim_common_tail(&a, &b, xecfg->ctxlen);
133
134 return xdl_diff(&a, &b, xpp, xecfg, xecb);
135 }
136
137 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
138 xdiff_emit_consume_fn fn, void *consume_callback_data,
139 xpparam_t const *xpp,
140 xdemitconf_t const *xecfg, xdemitcb_t *xecb)
141 {
142 int ret;
143 struct xdiff_emit_state state;
144
145 memset(&state, 0, sizeof(state));
146 state.consume = fn;
147 state.consume_callback_data = consume_callback_data;
148 xecb->outf = xdiff_outf;
149 xecb->priv = &state;
150 strbuf_init(&state.remainder, 0);
151 ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
152 strbuf_release(&state.remainder);
153 return ret;
154 }
155
156 int read_mmfile(mmfile_t *ptr, const char *filename)
157 {
158 struct stat st;
159 FILE *f;
160 size_t sz;
161
162 if (stat(filename, &st))
163 return error("Could not stat %s", filename);
164 if ((f = fopen(filename, "rb")) == NULL)
165 return error("Could not open %s", filename);
166 sz = xsize_t(st.st_size);
167 ptr->ptr = xmalloc(sz ? sz : 1);
168 if (sz && fread(ptr->ptr, sz, 1, f) != 1)
169 return error("Could not read %s", filename);
170 fclose(f);
171 ptr->size = sz;
172 return 0;
173 }
174
175 #define FIRST_FEW_BYTES 8000
176 int buffer_is_binary(const char *ptr, unsigned long size)
177 {
178 if (FIRST_FEW_BYTES < size)
179 size = FIRST_FEW_BYTES;
180 return !!memchr(ptr, 0, size);
181 }
182
183 struct ff_regs {
184 int nr;
185 struct ff_reg {
186 regex_t re;
187 int negate;
188 } *array;
189 };
190
191 static long ff_regexp(const char *line, long len,
192 char *buffer, long buffer_size, void *priv)
193 {
194 char *line_buffer = xstrndup(line, len); /* make NUL terminated */
195 struct ff_regs *regs = priv;
196 regmatch_t pmatch[2];
197 int i;
198 int result = -1;
199
200 for (i = 0; i < regs->nr; i++) {
201 struct ff_reg *reg = regs->array + i;
202 if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
203 if (reg->negate)
204 goto fail;
205 break;
206 }
207 }
208 if (regs->nr <= i)
209 goto fail;
210 i = pmatch[1].rm_so >= 0 ? 1 : 0;
211 line += pmatch[i].rm_so;
212 result = pmatch[i].rm_eo - pmatch[i].rm_so;
213 if (result > buffer_size)
214 result = buffer_size;
215 else
216 while (result > 0 && (isspace(line[result - 1])))
217 result--;
218 memcpy(buffer, line, result);
219 fail:
220 free(line_buffer);
221 return result;
222 }
223
224 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
225 {
226 int i;
227 struct ff_regs *regs;
228
229 xecfg->find_func = ff_regexp;
230 regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
231 for (i = 0, regs->nr = 1; value[i]; i++)
232 if (value[i] == '\n')
233 regs->nr++;
234 regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
235 for (i = 0; i < regs->nr; i++) {
236 struct ff_reg *reg = regs->array + i;
237 const char *ep = strchr(value, '\n'), *expression;
238 char *buffer = NULL;
239
240 reg->negate = (*value == '!');
241 if (reg->negate && i == regs->nr - 1)
242 die("Last expression must not be negated: %s", value);
243 if (*value == '!')
244 value++;
245 if (ep)
246 expression = buffer = xstrndup(value, ep - value);
247 else
248 expression = value;
249 if (regcomp(&reg->re, expression, cflags))
250 die("Invalid regexp to look for hunk header: %s", expression);
251 free(buffer);
252 value = ep + 1;
253 }
254 }
255
256 int git_xmerge_style = -1;
257
258 int git_xmerge_config(const char *var, const char *value, void *cb)
259 {
260 if (!strcasecmp(var, "merge.conflictstyle")) {
261 if (!value)
262 die("'%s' is not a boolean", var);
263 if (!strcmp(value, "diff3"))
264 git_xmerge_style = XDL_MERGE_DIFF3;
265 else if (!strcmp(value, "merge"))
266 git_xmerge_style = 0;
267 else
268 die("unknown style '%s' given for '%s'",
269 value, var);
270 return 0;
271 }
272 return git_default_config(var, value, cb);
273 }
274