From 0074aba1c0d3b073c635fdc1d5754dc6a6b6b7b9 Mon Sep 17 00:00:00 2001 From: Jakub Narebski Date: Thu, 26 Oct 2006 05:44:49 +0200 Subject: diff-format.txt: Combined diff format documentation supplement Update example combined diff format to the current version $ git diff-tree -p -c fec9ebf16c948bcb4a8b88d0173ee63584bcde76 and provide complete first chunk in example. Document combined diff format headers: how "diff header" look like, which of "extended diff headers" are used with combined diff and how they look like, differences in two-line from-file/to-file header from non-combined diff format, chunk header format. It should be noted that combined diff format was designed for quick _content_ inspection and renames would work correctly to pick which blobs from each tree to compare but otherwise not reflected in the output (the pathnames are not shown). [jc: with minimum copyediting] Signed-off-by: Jakub Narebski Signed-off-by: Junio C Hamano --- Documentation/diff-format.txt | 76 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 68 insertions(+), 8 deletions(-) (limited to 'Documentation/diff-format.txt') diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt index 617d8f526f..174d63a1ee 100644 --- a/Documentation/diff-format.txt +++ b/Documentation/diff-format.txt @@ -156,31 +156,91 @@ to produce 'combined diff', which looks like this: ------------ diff --combined describe.c -@@@ +98,7 @@@ - return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1; +index fabadb8,cc95eb0..4866510 +--- a/describe.c ++++ b/describe.c +@@@ -98,20 -98,12 +98,20 @@@ + return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1; } - + - static void describe(char *arg) -static void describe(struct commit *cmit, int last_one) ++static void describe(char *arg, int last_one) { - + unsigned char sha1[20]; - + struct commit *cmit; + + unsigned char sha1[20]; + + struct commit *cmit; + struct commit_list *list; + static int initialized = 0; + struct commit_name *n; + + + if (get_sha1(arg, sha1) < 0) + + usage(describe_usage); + + cmit = lookup_commit_reference(sha1); + + if (!cmit) + + usage(describe_usage); + + + if (!initialized) { + initialized = 1; + for_each_ref(get_name); ------------ +1. It is preceded with a "git diff" header, that looks like + this (when '-c' option is used): + + diff --combined file ++ +or like this (when '--cc' option is used): + + diff --c file + +2. It is followed by one or more extended header lines + (this example shows a merge with two parents): + + index ,.. + mode ,.. + new file mode + deleted file mode , ++ +The `mode ,..` line appears only if at least one of +the is diferent from the rest. Extended headers with +information about detected contents movement (renames and +copying detection) are designed to work with diff of two + and are not used by combined diff format. + +3. It is followed by two-line from-file/to-file header + + --- a/file + +++ b/file ++ +Contrary to two-line header for traditional 'unified' diff +format, and similar to filenames in ordinary "diff header", +/dev/null is not used for creation or deletion. + +4. Chunk header format is modified to prevent people from + accidentally feeding it to `patch -p1`. Combined diff format + was created for review of merge commit changes, and was not + meant for apply. The change is similar to the change in the + extended 'index' header: + + @@@ @@@ ++ +There are (number of parents + 1) `@` characters in the chunk +header for combined diff format. + Unlike the traditional 'unified' diff format, which shows two files A and B with a single column that has `-` (minus -- appears in A but removed in B), `+` (plus -- missing in A but -added to B), or ` ` (space -- unchanged) prefix, this format +added to B), or `" "` (space -- unchanged) prefix, this format compares two or more files file1, file2,... with one file X, and shows how X differs from each of fileN. One column for each of fileN is prepended to the output line to note how X's line is different from it. A `-` character in the column N means that the line appears in -fileN but it does not appear in the last file. A `+` character +fileN but it does not appear in the result. A `+` character in the column N means that the line appears in the last file, -and fileN does not have that line. +and fileN does not have that line (in other words, the line was +added, from the point of view of that parent). In the above example output, the function signature was changed from both files (hence two `-` removals from both file1 and -- cgit v1.3 From d5f6a01af0658bc0ec5f068d81ba321be94526d5 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Thu, 26 Oct 2006 00:05:04 -0700 Subject: combine-diff: a few more finishing touches. "new file" and "deleted file" were already reported in the original code, but the logic was not as transparent as it could have. This uses a few variables and more comments to clarify the flow. The rule is: (1) if a path exists in the merge result when no parent had it, we report "new" (otherwise it came from the parents, as opposed to have added by the evil merge). (2) if the path does not exist in the merge result, it is "deleted". Since we can say "new" and "deleted", there is no reason not to follow the /dev/null convention. This fixes it. Appending function name after @@@ ... @@@ is trivial, so implement it. Signed-off-by: Junio C Hamano --- Documentation/diff-format.txt | 6 +++--- combine-diff.c | 48 ++++++++++++++++++++++++++++++++++++++----- 2 files changed, 46 insertions(+), 8 deletions(-) (limited to 'Documentation/diff-format.txt') diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt index 174d63a1ee..ed4ebcbab7 100644 --- a/Documentation/diff-format.txt +++ b/Documentation/diff-format.txt @@ -212,9 +212,9 @@ copying detection) are designed to work with diff of two --- a/file +++ b/file + -Contrary to two-line header for traditional 'unified' diff -format, and similar to filenames in ordinary "diff header", -/dev/null is not used for creation or deletion. +Similar to two-line header for traditional 'unified' diff +format, `/dev/null` is used to signal created or deleted +files. 4. Chunk header format is modified to prevent people from accidentally feeding it to `patch -p1`. Combined diff format diff --git a/combine-diff.c b/combine-diff.c index 46d9121baf..01a8437f5c 100644 --- a/combine-diff.c +++ b/combine-diff.c @@ -489,6 +489,12 @@ static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long printf(" -%lu,%lu", l0, l1-l0); } +static int hunk_comment_line(const char *bol) +{ + int ch = *bol & 0xff; + return (isalpha(ch) || ch == '_' || ch == '$'); +} + static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent, int use_color) { @@ -508,8 +514,13 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent, struct sline *sl = &sline[lno]; unsigned long hunk_end; unsigned long rlines; - while (lno <= cnt && !(sline[lno].flag & mark)) + const char *hunk_comment = NULL; + + while (lno <= cnt && !(sline[lno].flag & mark)) { + if (hunk_comment_line(sline[lno].bol)) + hunk_comment = sline[lno].bol; lno++; + } if (cnt < lno) break; else { @@ -526,6 +537,22 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent, show_parent_lno(sline, lno, hunk_end, i); printf(" +%lu,%lu ", lno+1, rlines); for (i = 0; i <= num_parent; i++) putchar(combine_marker); + + if (hunk_comment) { + int comment_end = 0; + for (i = 0; i < 40; i++) { + int ch = hunk_comment[i] & 0xff; + if (!ch || ch == '\n') + break; + if (!isspace(ch)) + comment_end = i; + } + if (comment_end) + putchar(' '); + for (i = 0; i < comment_end; i++) + putchar(hunk_comment[i]); + } + printf("%s\n", c_reset); while (lno < hunk_end) { struct lline *ll; @@ -707,6 +734,8 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, int use_color = opt->color_diff; const char *c_meta = diff_get_color(use_color, DIFF_METAINFO); const char *c_reset = diff_get_color(use_color, DIFF_RESET); + int added = 0; + int deleted = 0; if (rev->loginfo) show_log(rev, opt->msg_sep); @@ -722,7 +751,10 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, printf("..%s%s\n", abb, c_reset); if (mode_differs) { - int added = !!elem->mode; + deleted = !elem->mode; + + /* We say it was added if nobody had it */ + added = !deleted; for (i = 0; added && i < num_parent; i++) if (elem->parent[i].status != DIFF_STATUS_ADDED) @@ -731,7 +763,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, printf("%snew file mode %06o", c_meta, elem->mode); else { - if (!elem->mode) + if (deleted) printf("%sdeleted file ", c_meta); printf("mode "); for (i = 0; i < num_parent; i++) { @@ -743,8 +775,14 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, } printf("%s\n", c_reset); } - dump_quoted_path("--- a/", elem->path, c_meta, c_reset); - dump_quoted_path("+++ b/", elem->path, c_meta, c_reset); + if (added) + dump_quoted_path("--- /dev/", "null", c_meta, c_reset); + else + dump_quoted_path("--- a/", elem->path, c_meta, c_reset); + if (deleted) + dump_quoted_path("+++ /dev/", "null", c_meta, c_reset); + else + dump_quoted_path("+++ b/", elem->path, c_meta, c_reset); dump_sline(sline, cnt, num_parent, opt->color_diff); } free(result); -- cgit v1.3