Refactor parse_loc

We want to use the same style of -L n,m argument for 'git log -L' as
for git-blame.  Refactor the argument parsing of the range arguments
from builtin/blame.c to the (new) file that will hold the 'git log -L'
logic.

To accommodate different data structures in blame and log -L, the file
contents are abstracted away; parse_range_arg takes a callback that it
uses to get the contents of a line of the (notional) file.

The new test is for a case that made me pause during debugging: the
'blame -L with invalid end' test was the only one that noticed an
outright failure to parse the end *at all*.  So make a more explicit
test for that.

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Bo Yang 2013-03-28 17:47:30 +01:00 committed by Junio C Hamano
parent 443d803e0d
commit 25ed3412f8
7 changed files with 151 additions and 109 deletions

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@ -13,24 +13,7 @@
Annotate only the given line range. <start> and <end> can take
one of these forms:
- number
+
If <start> or <end> is a number, it specifies an
absolute line number (lines count from 1).
+
- /regex/
+
This form will use the first line matching the given
POSIX regex. If <end> is a regex, it will search
starting at the line given by <start>.
+
- +offset or -offset
+
This is only valid for <end> and will specify a number
of lines before or after the line given by <start>.
+
include::line-range-format.txt[]
-l::
Show long rev (Default: off).

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@ -0,0 +1,18 @@
- number
+
If <start> or <end> is a number, it specifies an
absolute line number (lines count from 1).
+
- /regex/
+
This form will use the first line matching the given
POSIX regex. If <end> is a regex, it will search
starting at the line given by <start>.
+
- +offset or -offset
+
This is only valid for <end> and will specify a number
of lines before or after the line given by <start>.
+

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@ -683,6 +683,7 @@ LIB_H += help.h
LIB_H += http.h
LIB_H += kwset.h
LIB_H += levenshtein.h
LIB_H += line-range.h
LIB_H += list-objects.h
LIB_H += ll-merge.h
LIB_H += log-tree.h
@ -798,6 +799,7 @@ LIB_OBJS += hex.o
LIB_OBJS += ident.o
LIB_OBJS += kwset.o
LIB_OBJS += levenshtein.o
LIB_OBJS += line-range.o
LIB_OBJS += list-objects.o
LIB_OBJS += ll-merge.o
LIB_OBJS += lockfile.o

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@ -21,6 +21,7 @@
#include "parse-options.h"
#include "utf8.h"
#include "userdiff.h"
#include "line-range.h"
static char blame_usage[] = N_("git blame [options] [rev-opts] [rev] [--] file");
@ -566,11 +567,16 @@ static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
dst->score = 0;
}
static const char *nth_line(struct scoreboard *sb, int lno)
static const char *nth_line(struct scoreboard *sb, long lno)
{
return sb->final_buf + sb->lineno[lno];
}
static const char *nth_line_cb(void *data, long lno)
{
return nth_line((struct scoreboard *)data, lno);
}
/*
* It is known that lines between tlno to same came from parent, and e
* has an overlap with that range. it also is known that parent's
@ -1926,83 +1932,6 @@ static const char *add_prefix(const char *prefix, const char *path)
return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
}
/*
* Parsing of (comma separated) one item in the -L option
*/
static const char *parse_loc(const char *spec,
struct scoreboard *sb, long lno,
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 (spec[0] == '-')
num = 0 - num;
if (0 < num)
*ret = begin + num - 2;
else if (!num)
*ret = begin;
else
*ret = begin + num;
return term;
}
return spec;
}
num = strtol(spec, &term, 10);
if (term != spec) {
*ret = num;
return term;
}
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;
/* try [spec+1 .. term-1] as regexp */
*term = 0;
begin--; /* input is in human terms */
line = nth_line(sb, begin);
if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
!(reg_error = regexec(&regexp, line, 1, match, 0))) {
const char *cp = line + match[0].rm_so;
const char *nline;
while (begin++ < lno) {
nline = nth_line(sb, begin);
if (line <= cp && cp < nline)
break;
line = nline;
}
*ret = begin;
regfree(&regexp);
*term++ = '/';
return term;
}
else {
char errbuf[1024];
regerror(reg_error, &regexp, errbuf, 1024);
die("-L parameter '%s': %s", spec + 1, errbuf);
}
}
/*
* Parsing of -L option
*/
@ -2011,15 +1940,7 @@ static void prepare_blame_range(struct scoreboard *sb,
long lno,
long *bottom, long *top)
{
const char *term;
term = parse_loc(bottomtop, sb, lno, 1, bottom);
if (*term == ',') {
term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
if (*term)
usage(blame_usage);
}
if (*term)
if (parse_range_arg(bottomtop, nth_line_cb, sb, lno, bottom, top))
usage(blame_usage);
}
@ -2569,10 +2490,6 @@ parse_done:
bottom = top = 0;
if (bottomtop)
prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
if (bottom && top && top < bottom) {
long tmp;
tmp = top; top = bottom; bottom = tmp;
}
if (bottom < 1)
bottom = 1;
if (top < 1)

92
line-range.c Normal file
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@ -0,0 +1,92 @@
#include "git-compat-util.h"
#include "line-range.h"
/*
* Parse one item in the -L option
*/
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 (spec[0] == '-')
num = 0 - num;
if (0 < num)
*ret = begin + num - 2;
else if (!num)
*ret = begin;
else
*ret = begin + num;
return term;
}
return spec;
}
num = strtol(spec, &term, 10);
if (term != spec) {
*ret = num;
return term;
}
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;
/* try [spec+1 .. term-1] as regexp */
*term = 0;
begin--; /* input is in human terms */
line = nth_line(data, begin);
if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
!(reg_error = regexec(&regexp, 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(&regexp);
*term++ = '/';
return term;
}
else {
char errbuf[1024];
regerror(reg_error, &regexp, errbuf, 1024);
die("-L parameter '%s': %s", spec + 1, errbuf);
}
}
int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
void *cb_data, long lines, long *begin, long *end)
{
arg = parse_loc(arg, nth_line_cb, cb_data, lines, 1, begin);
if (*arg == ',')
arg = parse_loc(arg + 1, nth_line_cb, cb_data, lines, *begin + 1, end);
if (*arg)
return -1;
return 0;
}

24
line-range.h Normal file
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@ -0,0 +1,24 @@
#ifndef LINE_RANGE_H
#define LINE_RANGE_H
/*
* Parse one item in an -L begin,end option w.r.t. the notional file
* object 'cb_data' consisting of 'lines' lines.
*
* The 'nth_line_cb' callback is used to determine the start of the
* line 'lno' inside the 'cb_data'. The caller is expected to already
* have a suitable map at hand to make this a constant-time lookup.
*
* Returns 0 in case of success and -1 if there was an error. The
* actual range is stored in *begin and *end. The counting starts
* at 1! In case of error, the caller should show usage message.
*/
typedef const char *(*nth_line_fn_t)(void *data, long lno);
extern int parse_range_arg(const char *arg,
nth_line_fn_t nth_line_cb,
void *cb_data, long lines,
long *begin, long *end);
#endif /* LINE_RANGE_H */

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@ -175,6 +175,12 @@ test_expect_success 'blame -L with invalid end' '
grep "has only 2 lines" errors
'
test_expect_success 'blame parses <end> part of -L' '
git blame -L1,1 tres >out &&
cat out &&
test $(wc -l < out) -eq 1
'
test_expect_success 'indent of line numbers, nine lines' '
git blame nine_lines >actual &&
test $(grep -c " " actual) = 0