promisor-remote: skip move_to_tail when no-op
[git/git.git] / line-range.c
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1#include "git-compat-util.h"
2#include "line-range.h"
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3#include "xdiff-interface.h"
4#include "strbuf.h"
5#include "userdiff.h"
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6
7/*
8 * Parse one item in the -L option
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9 *
10 * 'begin' is applicable only to relative range anchors. Absolute anchors
11 * ignore this value.
12 *
13 * When parsing "-L A,B", parse_loc() is called once for A and once for B.
14 *
15 * When parsing A, 'begin' must be a negative number, the absolute value of
16 * which is the line at which relative start-of-range anchors should be
17 * based. Beginning of file is represented by -1.
18 *
19 * When parsing B, 'begin' must be the positive line number immediately
20 * following the line computed for 'A'.
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21 */
22static const char *parse_loc(const char *spec, nth_line_fn_t nth_line,
23 void *data, long lines, long begin, long *ret)
24{
25 char *term;
26 const char *line;
27 long num;
28 int reg_error;
29 regex_t regexp;
30 regmatch_t match[1];
31
32 /* Allow "-L <something>,+20" to mean starting at <something>
33 * for 20 lines, or "-L <something>,-5" for 5 lines ending at
34 * <something>.
35 */
5d57cac6 36 if (1 <= begin && (spec[0] == '+' || spec[0] == '-')) {
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37 num = strtol(spec + 1, &term, 10);
38 if (term != spec + 1) {
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39 if (!ret)
40 return term;
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41 if (num == 0)
42 die("-L invalid empty range");
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43 if (spec[0] == '-')
44 num = 0 - num;
45 if (0 < num)
46 *ret = begin + num - 2;
47 else if (!num)
48 *ret = begin;
49 else
96cfa94e 50 *ret = begin + num > 0 ? begin + num : 1;
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51 return term;
52 }
53 return spec;
54 }
55 num = strtol(spec, &term, 10);
56 if (term != spec) {
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57 if (ret) {
58 if (num <= 0)
59 die("-L invalid line number: %ld", num);
12da1d1f 60 *ret = num;
5ce922a0 61 }
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62 return term;
63 }
815834e9 64
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65 if (begin < 0) {
66 if (spec[0] != '^')
67 begin = -begin;
68 else {
69 begin = 1;
70 spec++;
71 }
72 }
815834e9 73
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74 if (spec[0] != '/')
75 return spec;
76
77 /* it could be a regexp of form /.../ */
78 for (term = (char *) spec + 1; *term && *term != '/'; term++) {
79 if (*term == '\\')
80 term++;
81 }
82 if (*term != '/')
83 return spec;
84
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85 /* in the scan-only case we are not interested in the regex */
86 if (!ret)
87 return term+1;
88
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89 /* try [spec+1 .. term-1] as regexp */
90 *term = 0;
91 begin--; /* input is in human terms */
92 line = nth_line(data, begin);
93
94 if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
95 !(reg_error = regexec(&regexp, line, 1, match, 0))) {
96 const char *cp = line + match[0].rm_so;
97 const char *nline;
98
99 while (begin++ < lines) {
100 nline = nth_line(data, begin);
101 if (line <= cp && cp < nline)
102 break;
103 line = nline;
104 }
105 *ret = begin;
106 regfree(&regexp);
107 *term++ = '/';
108 return term;
109 }
110 else {
111 char errbuf[1024];
112 regerror(reg_error, &regexp, errbuf, 1024);
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113 die("-L parameter '%s' starting at line %ld: %s",
114 spec + 1, begin + 1, errbuf);
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115 }
116}
117
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118static int match_funcname(xdemitconf_t *xecfg, const char *bol, const char *eol)
119{
120 if (xecfg) {
121 char buf[1];
122 return xecfg->find_func(bol, eol - bol, buf, 1,
123 xecfg->find_func_priv) >= 0;
124 }
125
126 if (bol == eol)
127 return 0;
128 if (isalpha(*bol) || *bol == '_' || *bol == '$')
129 return 1;
130 return 0;
131}
132
133static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char *start,
134 regex_t *regexp)
135{
136 int reg_error;
137 regmatch_t match[1];
138 while (1) {
139 const char *bol, *eol;
140 reg_error = regexec(regexp, start, 1, match, 0);
141 if (reg_error == REG_NOMATCH)
142 return NULL;
143 else if (reg_error) {
144 char errbuf[1024];
145 regerror(reg_error, regexp, errbuf, 1024);
146 die("-L parameter: regexec() failed: %s", errbuf);
147 }
148 /* determine extent of line matched */
149 bol = start+match[0].rm_so;
150 eol = start+match[0].rm_eo;
151 while (bol > start && *bol != '\n')
152 bol--;
153 if (*bol == '\n')
154 bol++;
155 while (*eol && *eol != '\n')
156 eol++;
157 if (*eol == '\n')
158 eol++;
159 /* is it a funcname line? */
160 if (match_funcname(xecfg, (char*) bol, (char*) eol))
161 return bol;
162 start = eol;
163 }
164}
165
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166static const char *parse_range_funcname(
167 const char *arg, nth_line_fn_t nth_line_cb,
168 void *cb_data, long lines, long anchor, long *begin, long *end,
169 const char *path, struct index_state *istate)
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170{
171 char *pattern;
172 const char *term;
173 struct userdiff_driver *drv;
174 xdemitconf_t *xecfg = NULL;
175 const char *start;
176 const char *p;
177 int reg_error;
178 regex_t regexp;
179
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180 if (*arg == '^') {
181 anchor = 1;
182 arg++;
183 }
184
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185 assert(*arg == ':');
186 term = arg+1;
187 while (*term && *term != ':') {
188 if (*term == '\\' && *(term+1))
189 term++;
190 term++;
191 }
192 if (term == arg+1)
193 return NULL;
194 if (!begin) /* skip_range_arg case */
195 return term;
196
197 pattern = xstrndup(arg+1, term-(arg+1));
198
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199 anchor--; /* input is in human terms */
200 start = nth_line_cb(cb_data, anchor);
13b8f68c 201
80e03855 202 drv = userdiff_find_by_path(istate, path);
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203 if (drv && drv->funcname.pattern) {
204 const struct userdiff_funcname *pe = &drv->funcname;
205 xecfg = xcalloc(1, sizeof(*xecfg));
206 xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
207 }
208
209 reg_error = regcomp(&regexp, pattern, REG_NEWLINE);
210 if (reg_error) {
211 char errbuf[1024];
212 regerror(reg_error, &regexp, errbuf, 1024);
213 die("-L parameter '%s': %s", pattern, errbuf);
214 }
215
216 p = find_funcname_matching_regexp(xecfg, (char*) start, &regexp);
217 if (!p)
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218 die("-L parameter '%s' starting at line %ld: no match",
219 pattern, anchor + 1);
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220 *begin = 0;
221 while (p > nth_line_cb(cb_data, *begin))
222 (*begin)++;
223
224 if (*begin >= lines)
225 die("-L parameter '%s' matches at EOF", pattern);
226
227 *end = *begin+1;
228 while (*end < lines) {
229 const char *bol = nth_line_cb(cb_data, *end);
230 const char *eol = nth_line_cb(cb_data, *end+1);
231 if (match_funcname(xecfg, bol, eol))
232 break;
233 (*end)++;
234 }
235
236 regfree(&regexp);
237 free(xecfg);
238 free(pattern);
239
240 /* compensate for 1-based numbering */
241 (*begin)++;
242
243 return term;
244}
245
25ed3412 246int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
815834e9 247 void *cb_data, long lines, long anchor,
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248 long *begin, long *end,
249 const char *path, struct index_state *istate)
25ed3412 250{
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251 *begin = *end = 0;
252
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253 if (anchor < 1)
254 anchor = 1;
255 if (anchor > lines)
256 anchor = lines + 1;
257
215e76c7 258 if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':')) {
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259 arg = parse_range_funcname(arg, nth_line_cb, cb_data,
260 lines, anchor, begin, end,
261 path, istate);
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262 if (!arg || *arg)
263 return -1;
264 return 0;
265 }
266
815834e9 267 arg = parse_loc(arg, nth_line_cb, cb_data, lines, -anchor, begin);
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268
269 if (*arg == ',')
270 arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end);
271
272 if (*arg)
273 return -1;
274
3bf65f9e 275 if (*begin && *end && *end < *begin) {
35d803bc 276 SWAP(*end, *begin);
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277 }
278
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279 return 0;
280}
12da1d1f 281
80e03855 282const char *skip_range_arg(const char *arg, struct index_state *istate)
12da1d1f 283{
215e76c7 284 if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':'))
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285 return parse_range_funcname(arg, NULL, NULL,
286 0, 0, NULL, NULL,
287 NULL, istate);
13b8f68c 288
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289 arg = parse_loc(arg, NULL, NULL, 0, -1, NULL);
290
291 if (*arg == ',')
292 arg = parse_loc(arg+1, NULL, NULL, 0, 0, NULL);
293
294 return arg;
295}