diff: add option to show whole functions as context
[git/git.git] / xdiff / xemit.c
CommitLineData
3443546f
LT
1/*
2 * LibXDiff by Davide Libenzi ( File Differential Library )
3 * Copyright (C) 2003 Davide Libenzi
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 * Davide Libenzi <davidel@xmailserver.org>
20 *
21 */
22
23#include "xinclude.h"
24
25
26
27
28static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec);
29static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb);
3443546f
LT
30
31
32
33
34static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
35
36 *rec = xdf->recs[ri]->ptr;
37
38 return xdf->recs[ri]->size;
39}
40
41
42static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
43 long size, psize = strlen(pre);
44 char const *rec;
45
46 size = xdl_get_rec(xdf, ri, &rec);
47 if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
48
49 return -1;
50 }
51
52 return 0;
53}
54
55
56/*
57 * Starting at the passed change atom, find the latest change atom to be included
58 * inside the differential hunk according to the specified configuration.
59 */
ef2e62fe 60xdchange_t *xdl_get_hunk(xdchange_t *xscr, xdemitconf_t const *xecfg) {
3443546f 61 xdchange_t *xch, *xchp;
6d0e674a 62 long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
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LT
63
64 for (xchp = xscr, xch = xscr->next; xch; xchp = xch, xch = xch->next)
6d0e674a 65 if (xch->i1 - (xchp->i1 + xchp->chg1) > max_common)
3443546f
LT
66 break;
67
68 return xchp;
69}
70
71
f258475a
JH
72static long def_ff(const char *rec, long len, char *buf, long sz, void *priv)
73{
74 if (len > 0 &&
75 (isalpha((unsigned char)*rec) || /* identifier? */
76 *rec == '_' || /* also identifier? */
77 *rec == '$')) { /* identifiers from VMS and other esoterico */
78 if (len > sz)
79 len = sz;
80 while (0 < len && isspace((unsigned char)rec[len - 1]))
81 len--;
82 memcpy(buf, rec, len);
83 return len;
84 }
85 return -1;
86}
87
52fae7de
PH
88static int xdl_emit_common(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
89 xdemitconf_t const *xecfg) {
a9ed376b
LT
90 xdfile_t *xdf = &xe->xdf1;
91 const char *rchg = xdf->rchg;
92 long ix;
93
94 for (ix = 0; ix < xdf->nrec; ix++) {
95 if (rchg[ix])
96 continue;
97 if (xdl_emit_record(xdf, ix, "", ecb))
98 return -1;
99 }
100 return 0;
101}
102
f99f4b36
RS
103struct func_line {
104 long len;
105 char buf[80];
106};
107
14937c2c 108static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
f99f4b36
RS
109 struct func_line *func_line, long start, long limit)
110{
111 find_func_t ff = xecfg->find_func ? xecfg->find_func : def_ff;
14937c2c
RS
112 long l, size, step = (start > limit) ? -1 : 1;
113 char *buf, dummy[1];
f99f4b36 114
14937c2c
RS
115 buf = func_line ? func_line->buf : dummy;
116 size = func_line ? sizeof(func_line->buf) : sizeof(dummy);
117
118 for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
f99f4b36
RS
119 const char *rec;
120 long reclen = xdl_get_rec(&xe->xdf1, l, &rec);
121 long len = ff(rec, reclen, buf, size, xecfg->find_func_priv);
122 if (len >= 0) {
14937c2c
RS
123 if (func_line)
124 func_line->len = len;
125 return l;
f99f4b36
RS
126 }
127 }
14937c2c 128 return -1;
f99f4b36
RS
129}
130
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LT
131int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
132 xdemitconf_t const *xecfg) {
133 long s1, s2, e1, e2, lctx;
134 xdchange_t *xch, *xche;
c099789b 135 long funclineprev = -1;
f99f4b36 136 struct func_line func_line = { 0 };
3443546f 137
a9ed376b
LT
138 if (xecfg->flags & XDL_EMIT_COMMON)
139 return xdl_emit_common(xe, xscr, ecb, xecfg);
140
8e24cbae 141 for (xch = xscr; xch; xch = xche->next) {
3443546f
LT
142 xche = xdl_get_hunk(xch, xecfg);
143
144 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
145 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
146
14937c2c
RS
147 if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
148 long fs1 = get_func_line(xe, xecfg, NULL, xch->i1, -1);
149 if (fs1 < 0)
150 fs1 = 0;
151 if (fs1 < s1) {
152 s2 -= s1 - fs1;
153 s1 = fs1;
154 }
155 }
156
157 again:
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LT
158 lctx = xecfg->ctxlen;
159 lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
160 lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
161
162 e1 = xche->i1 + xche->chg1 + lctx;
163 e2 = xche->i2 + xche->chg2 + lctx;
164
14937c2c
RS
165 if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
166 long fe1 = get_func_line(xe, xecfg, NULL,
167 xche->i1 + xche->chg1,
168 xe->xdf1.nrec);
169 if (fe1 < 0)
170 fe1 = xe->xdf1.nrec;
171 if (fe1 > e1) {
172 e2 += fe1 - e1;
173 e1 = fe1;
174 }
175
176 /*
177 * Overlap with next change? Then include it
178 * in the current hunk and start over to find
179 * its new end.
180 */
181 if (xche->next) {
182 long l = xche->next->i1;
183 if (l <= e1 ||
184 get_func_line(xe, xecfg, NULL, l, e1) < 0) {
185 xche = xche->next;
186 goto again;
187 }
188 }
189 }
190
3443546f
LT
191 /*
192 * Emit current hunk header.
193 */
acb72577
MW
194
195 if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
f99f4b36
RS
196 get_func_line(xe, xecfg, &func_line,
197 s1 - 1, funclineprev);
c099789b 198 funclineprev = s1 - 1;
acb72577
MW
199 }
200 if (xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
f99f4b36 201 func_line.buf, func_line.len, ecb) < 0)
3443546f
LT
202 return -1;
203
204 /*
205 * Emit pre-context.
206 */
207 for (; s1 < xch->i1; s1++)
208 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
209 return -1;
210
211 for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
212 /*
213 * Merge previous with current change atom.
214 */
215 for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
216 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
217 return -1;
218
219 /*
220 * Removes lines from the first file.
221 */
222 for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
223 if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
224 return -1;
225
226 /*
227 * Adds lines from the second file.
228 */
229 for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
230 if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
231 return -1;
232
233 if (xch == xche)
234 break;
235 s1 = xch->i1 + xch->chg1;
236 s2 = xch->i2 + xch->chg2;
237 }
238
239 /*
240 * Emit post-context.
241 */
242 for (s1 = xche->i1 + xche->chg1; s1 < e1; s1++)
243 if (xdl_emit_record(&xe->xdf1, s1, " ", ecb) < 0)
244 return -1;
245 }
246
247 return 0;
248}