line-range.c

   1 #include "git-compat-util.h"
   2 #include "line-range.h"
   3 #include "xdiff-interface.h"
   4 #include "strbuf.h"
   5 #include "userdiff.h"
   6
   7 /*
   8  * Parse one item in the -L option
   9  */
  10 static const char *parse_loc(const char *spec, nth_line_fn_t nth_line,
  11                              void *data, long lines, long begin, long *ret)
  12 {
  13         char *term;
  14         const char *line;
  15         long num;
  16         int reg_error;
  17         regex_t regexp;
  18         regmatch_t match[1];
  19
  20         /* Allow "-L <something>,+20" to mean starting at <something>
  21          * for 20 lines, or "-L <something>,-5" for 5 lines ending at
  22          * <something>.
  23          */
  24         if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
  25                 num = strtol(spec + 1, &term, 10);
  26                 if (term != spec + 1) {
  27                         if (!ret)
  28                                 return term;
  29                         if (spec[0] == '-')
  30                                 num = 0 - num;
  31                         if (0 < num)
  32                                 *ret = begin + num - 2;
  33                         else if (!num)
  34                                 *ret = begin;
  35                         else
  36                                 *ret = begin + num;
  37                         return term;
  38                 }
  39                 return spec;
  40         }
  41         num = strtol(spec, &term, 10);
  42         if (term != spec) {
  43                 if (ret)
  44                         *ret = num;
  45                 return term;
  46         }
  47         if (spec[0] != '/')
  48                 return spec;
  49
  50         /* it could be a regexp of form /.../ */
  51         for (term = (char *) spec + 1; *term && *term != '/'; term++) {
  52                 if (*term == '\\')
  53                         term++;
  54         }
  55         if (*term != '/')
  56                 return spec;
  57
  58         /* in the scan-only case we are not interested in the regex */
  59         if (!ret)
  60                 return term+1;
  61
  62         /* try [spec+1 .. term-1] as regexp */
  63         *term = 0;
  64         begin--; /* input is in human terms */
  65         line = nth_line(data, begin);
  66
  67         if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
  68             !(reg_error = regexec(&regexp, line, 1, match, 0))) {
  69                 const char *cp = line + match[0].rm_so;
  70                 const char *nline;
  71
  72                 while (begin++ < lines) {
  73                         nline = nth_line(data, begin);
  74                         if (line <= cp && cp < nline)
  75                                 break;
  76                         line = nline;
  77                 }
  78                 *ret = begin;
  79                 regfree(&regexp);
  80                 *term++ = '/';
  81                 return term;
  82         }
  83         else {
  84                 char errbuf[1024];
  85                 regerror(reg_error, &regexp, errbuf, 1024);
  86                 die("-L parameter '%s': %s", spec + 1, errbuf);
  87         }
  88 }
  89
  90 static int match_funcname(xdemitconf_t *xecfg, const char *bol, const char *eol)
  91 {
  92         if (xecfg) {
  93                 char buf[1];
  94                 return xecfg->find_func(bol, eol - bol, buf, 1,
  95                                         xecfg->find_func_priv) >= 0;
  96         }
  97
  98         if (bol == eol)
  99                 return 0;
 100         if (isalpha(*bol) || *bol == '_' || *bol == '$')
 101                 return 1;
 102         return 0;
 103 }
 104
 105 static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char *start,
 106                                                  regex_t *regexp)
 107 {
 108         int reg_error;
 109         regmatch_t match[1];
 110         while (1) {
 111                 const char *bol, *eol;
 112                 reg_error = regexec(regexp, start, 1, match, 0);
 113                 if (reg_error == REG_NOMATCH)
 114                         return NULL;
 115                 else if (reg_error) {
 116                         char errbuf[1024];
 117                         regerror(reg_error, regexp, errbuf, 1024);
 118                         die("-L parameter: regexec() failed: %s", errbuf);
 119                 }
 120                 /* determine extent of line matched */
 121                 bol = start+match[0].rm_so;
 122                 eol = start+match[0].rm_eo;
 123                 while (bol > start && *bol != '\n')
 124                         bol--;
 125                 if (*bol == '\n')
 126                         bol++;
 127                 while (*eol && *eol != '\n')
 128                         eol++;
 129                 if (*eol == '\n')
 130                         eol++;
 131                 /* is it a funcname line? */
 132                 if (match_funcname(xecfg, (char*) bol, (char*) eol))
 133                         return bol;
 134                 start = eol;
 135         }
 136 }
 137
 138 static const char *parse_range_funcname(const char *arg, nth_line_fn_t nth_line_cb,
 139                                         void *cb_data, long lines, long *begin, long *end,
 140                                         const char *path)
 141 {
 142         char *pattern;
 143         const char *term;
 144         struct userdiff_driver *drv;
 145         xdemitconf_t *xecfg = NULL;
 146         const char *start;
 147         const char *p;
 148         int reg_error;
 149         regex_t regexp;
 150
 151         assert(*arg == ':');
 152         term = arg+1;
 153         while (*term && *term != ':') {
 154                 if (*term == '\\' && *(term+1))
 155                         term++;
 156                 term++;
 157         }
 158         if (term == arg+1)
 159                 return NULL;
 160         if (!begin) /* skip_range_arg case */
 161                 return term;
 162
 163         pattern = xstrndup(arg+1, term-(arg+1));
 164
 165         start = nth_line_cb(cb_data, 0);
 166
 167         drv = userdiff_find_by_path(path);
 168         if (drv && drv->funcname.pattern) {
 169                 const struct userdiff_funcname *pe = &drv->funcname;
 170                 xecfg = xcalloc(1, sizeof(*xecfg));
 171                 xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
 172         }
 173
 174         reg_error = regcomp(&regexp, pattern, REG_NEWLINE);
 175         if (reg_error) {
 176                 char errbuf[1024];
 177                 regerror(reg_error, &regexp, errbuf, 1024);
 178                 die("-L parameter '%s': %s", pattern, errbuf);
 179         }
 180
 181         p = find_funcname_matching_regexp(xecfg, (char*) start, &regexp);
 182         if (!p)
 183                 die("-L parameter '%s': no match", pattern);
 184         *begin = 0;
 185         while (p > nth_line_cb(cb_data, *begin))
 186                 (*begin)++;
 187
 188         if (*begin >= lines)
 189                 die("-L parameter '%s' matches at EOF", pattern);
 190
 191         *end = *begin+1;
 192         while (*end < lines) {
 193                 const char *bol = nth_line_cb(cb_data, *end);
 194                 const char *eol = nth_line_cb(cb_data, *end+1);
 195                 if (match_funcname(xecfg, bol, eol))
 196                         break;
 197                 (*end)++;
 198         }
 199
 200         regfree(&regexp);
 201         free(xecfg);
 202         free(pattern);
 203
 204         /* compensate for 1-based numbering */
 205         (*begin)++;
 206
 207         return term;
 208 }
 209
 210 int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
 211                     void *cb_data, long lines, long *begin, long *end,
 212                     const char *path)
 213 {
 214         if (*arg == ':') {
 215                 arg = parse_range_funcname(arg, nth_line_cb, cb_data, lines, begin, end, path);
 216                 if (!arg || *arg)
 217                         return -1;
 218                 return 0;
 219         }
 220
 221         arg = parse_loc(arg, nth_line_cb, cb_data, lines, 1, begin);
 222
 223         if (*arg == ',')
 224                 arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end);
 225
 226         if (*arg)
 227                 return -1;
 228
 229         return 0;
 230 }
 231
 232 const char *skip_range_arg(const char *arg)
 233 {
 234         if (*arg == ':')
 235                 return parse_range_funcname(arg, NULL, NULL, 0, NULL, NULL, NULL);
 236
 237         arg = parse_loc(arg, NULL, NULL, 0, -1, NULL);
 238
 239         if (*arg == ',')
 240                 arg = parse_loc(arg+1, NULL, NULL, 0, 0, NULL);
 241
 242         return arg;
 243 }