diff options
Diffstat (limited to 'line-range.c')
| -rw-r--r-- | line-range.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/line-range.c b/line-range.c new file mode 100644 index 0000000..955a8a9 --- /dev/null +++ b/line-range.c @@ -0,0 +1,295 @@ +#include "git-compat-util.h" +#include "line-range.h" +#include "xdiff-interface.h" +#include "strbuf.h" +#include "userdiff.h" + +/* + * Parse one item in the -L option + * + * 'begin' is applicable only to relative range anchors. Absolute anchors + * ignore this value. + * + * When parsing "-L A,B", parse_loc() is called once for A and once for B. + * + * When parsing A, 'begin' must be a negative number, the absolute value of + * which is the line at which relative start-of-range anchors should be + * based. Beginning of file is represented by -1. + * + * When parsing B, 'begin' must be the positive line number immediately + * following the line computed for 'A'. + */ +static const char *parse_loc(const char *spec, nth_line_fn_t nth_line, + void *data, long lines, long begin, long *ret) +{ + char *term; + const char *line; + long num; + int reg_error; + regex_t regexp; + regmatch_t match[1]; + + /* Allow "-L <something>,+20" to mean starting at <something> + * for 20 lines, or "-L <something>,-5" for 5 lines ending at + * <something>. + */ + if (1 <= begin && (spec[0] == '+' || spec[0] == '-')) { + num = strtol(spec + 1, &term, 10); + if (term != spec + 1) { + if (!ret) + return term; + if (num == 0) + die("-L invalid empty range"); + if (spec[0] == '-') + num = 0 - num; + if (0 < num) + *ret = begin + num - 2; + else if (!num) + *ret = begin; + else + *ret = begin + num > 0 ? begin + num : 1; + return term; + } + return spec; + } + num = strtol(spec, &term, 10); + if (term != spec) { + if (ret) { + if (num <= 0) + die("-L invalid line number: %ld", num); + *ret = num; + } + return term; + } + + if (begin < 0) { + if (spec[0] != '^') + begin = -begin; + else { + begin = 1; + spec++; + } + } + + if (spec[0] != '/') + return spec; + + /* it could be a regexp of form /.../ */ + for (term = (char *) spec + 1; *term && *term != '/'; term++) { + if (*term == '\\') + term++; + } + if (*term != '/') + return spec; + + /* in the scan-only case we are not interested in the regex */ + if (!ret) + return term+1; + + /* try [spec+1 .. term-1] as regexp */ + *term = 0; + begin--; /* input is in human terms */ + line = nth_line(data, begin); + + if (!(reg_error = regcomp(®exp, spec + 1, REG_NEWLINE)) && + !(reg_error = regexec(®exp, line, 1, match, 0))) { + const char *cp = line + match[0].rm_so; + const char *nline; + + while (begin++ < lines) { + nline = nth_line(data, begin); + if (line <= cp && cp < nline) + break; + line = nline; + } + *ret = begin; + regfree(®exp); + *term++ = '/'; + return term; + } + else { + char errbuf[1024]; + regerror(reg_error, ®exp, errbuf, 1024); + die("-L parameter '%s' starting at line %ld: %s", + spec + 1, begin + 1, errbuf); + } +} + +static int match_funcname(xdemitconf_t *xecfg, const char *bol, const char *eol) +{ + if (xecfg) { + char buf[1]; + return xecfg->find_func(bol, eol - bol, buf, 1, + xecfg->find_func_priv) >= 0; + } + + if (bol == eol) + return 0; + if (isalpha(*bol) || *bol == '_' || *bol == '$') + return 1; + return 0; +} + +static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char *start, + regex_t *regexp) +{ + int reg_error; + regmatch_t match[1]; + while (1) { + const char *bol, *eol; + reg_error = regexec(regexp, start, 1, match, 0); + if (reg_error == REG_NOMATCH) + return NULL; + else if (reg_error) { + char errbuf[1024]; + regerror(reg_error, regexp, errbuf, 1024); + die("-L parameter: regexec() failed: %s", errbuf); + } + /* determine extent of line matched */ + bol = start+match[0].rm_so; + eol = start+match[0].rm_eo; + while (bol > start && *bol != '\n') + bol--; + if (*bol == '\n') + bol++; + while (*eol && *eol != '\n') + eol++; + if (*eol == '\n') + eol++; + /* is it a funcname line? */ + if (match_funcname(xecfg, (char*) bol, (char*) eol)) + return bol; + start = eol; + } +} + +static const char *parse_range_funcname( + const char *arg, nth_line_fn_t nth_line_cb, + void *cb_data, long lines, long anchor, long *begin, long *end, + const char *path, struct index_state *istate) +{ + char *pattern; + const char *term; + struct userdiff_driver *drv; + xdemitconf_t *xecfg = NULL; + const char *start; + const char *p; + int reg_error; + regex_t regexp; + + if (*arg == '^') { + anchor = 1; + arg++; + } + + assert(*arg == ':'); + term = arg+1; + while (*term && *term != ':') { + if (*term == '\\' && *(term+1)) + term++; + term++; + } + if (term == arg+1) + return NULL; + if (!begin) /* skip_range_arg case */ + return term; + + pattern = xstrndup(arg+1, term-(arg+1)); + + anchor--; /* input is in human terms */ + start = nth_line_cb(cb_data, anchor); + + drv = userdiff_find_by_path(istate, path); + if (drv && drv->funcname.pattern) { + const struct userdiff_funcname *pe = &drv->funcname; + CALLOC_ARRAY(xecfg, 1); + xdiff_set_find_func(xecfg, pe->pattern, pe->cflags); + } + + reg_error = regcomp(®exp, pattern, REG_NEWLINE); + if (reg_error) { + char errbuf[1024]; + regerror(reg_error, ®exp, errbuf, 1024); + die("-L parameter '%s': %s", pattern, errbuf); + } + + p = find_funcname_matching_regexp(xecfg, (char*) start, ®exp); + if (!p) + die("-L parameter '%s' starting at line %ld: no match", + pattern, anchor + 1); + *begin = 0; + while (p > nth_line_cb(cb_data, *begin)) + (*begin)++; + + if (*begin >= lines) + die("-L parameter '%s' matches at EOF", pattern); + + *end = *begin+1; + while (*end < lines) { + const char *bol = nth_line_cb(cb_data, *end); + const char *eol = nth_line_cb(cb_data, *end+1); + if (match_funcname(xecfg, bol, eol)) + break; + (*end)++; + } + + regfree(®exp); + free(xecfg); + free(pattern); + + /* compensate for 1-based numbering */ + (*begin)++; + + return term; +} + +int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb, + void *cb_data, long lines, long anchor, + long *begin, long *end, + const char *path, struct index_state *istate) +{ + *begin = *end = 0; + + if (anchor < 1) + anchor = 1; + if (anchor > lines) + anchor = lines + 1; + + if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':')) { + arg = parse_range_funcname(arg, nth_line_cb, cb_data, + lines, anchor, begin, end, + path, istate); + if (!arg || *arg) + return -1; + return 0; + } + + arg = parse_loc(arg, nth_line_cb, cb_data, lines, -anchor, begin); + + if (*arg == ',') + arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end); + + if (*arg) + return -1; + + if (*begin && *end && *end < *begin) { + SWAP(*end, *begin); + } + + return 0; +} + +const char *skip_range_arg(const char *arg, struct index_state *istate) +{ + if (*arg == ':' || (*arg == '^' && *(arg + 1) == ':')) + return parse_range_funcname(arg, NULL, NULL, + 0, 0, NULL, NULL, + NULL, istate); + + arg = parse_loc(arg, NULL, NULL, 0, -1, NULL); + + if (*arg == ',') + arg = parse_loc(arg+1, NULL, NULL, 0, 0, NULL); + + return arg; +} |