From 07924d4d50e5304fb53eb60aaba8aef31d4c4e5e Mon Sep 17 00:00:00 2001 From: Michal Privoznik Date: Wed, 16 Jan 2013 08:51:58 +0100 Subject: [PATCH] diff: Introduce --diff-algorithm command line option Since command line options have higher priority than config file variables and taking previous commit into account, we need a way how to specify myers algorithm on command line. However, inventing `--myers` is not the right answer. We need far more general option, and that is `--diff-algorithm`. Signed-off-by: Michal Privoznik Signed-off-by: Junio C Hamano --- Documentation/diff-options.txt | 20 ++++++++++++++++++++ contrib/completion/git-completion.bash | 11 +++++++++++ diff.c | 12 +++++++++++- diff.h | 2 ++ merge-recursive.c | 9 +++++++++ 5 files changed, 53 insertions(+), 1 deletion(-) diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt index 39f2c5074..81e5be13d 100644 --- a/Documentation/diff-options.txt +++ b/Documentation/diff-options.txt @@ -55,6 +55,26 @@ endif::git-format-patch[] --histogram:: Generate a diff using the "histogram diff" algorithm. +--diff-algorithm={patience|minimal|histogram|myers}:: + Choose a diff algorithm. The variants are as follows: ++ +-- +`default`, `myers`;; + The basic greedy diff algorithm. Currently, this is the default. +`minimal`;; + Spend extra time to make sure the smallest possible diff is + produced. +`patience`;; + Use "patience diff" algorithm when generating patches. +`histogram`;; + This algorithm extends the patience algorithm to "support + low-occurrence common elements". +-- ++ +For instance, if you configured diff.algorithm variable to a +non-default value and want to use the default one, then you +have to use `--diff-algorithm=default` option. + --stat[=[,[,]]]:: Generate a diffstat. By default, as much space as necessary will be used for the filename part, and the rest for the graph diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash index 33e25dc08..d592cf9be 100644 --- a/contrib/completion/git-completion.bash +++ b/contrib/completion/git-completion.bash @@ -1021,6 +1021,8 @@ _git_describe () __gitcomp_nl "$(__git_refs)" } +__git_diff_algorithms="myers minimal patience histogram" + __git_diff_common_options="--stat --numstat --shortstat --summary --patch-with-stat --name-only --name-status --color --no-color --color-words --no-renames --check @@ -1035,6 +1037,7 @@ __git_diff_common_options="--stat --numstat --shortstat --summary --raw --dirstat --dirstat= --dirstat-by-file --dirstat-by-file= --cumulative + --diff-algorithm= " _git_diff () @@ -1042,6 +1045,10 @@ _git_diff () __git_has_doubledash && return case "$cur" in + --diff-algorithm=*) + __gitcomp "$__git_diff_algorithms" "" "${cur##--diff-algorithm=}" + return + ;; --*) __gitcomp "--cached --staged --pickaxe-all --pickaxe-regex --base --ours --theirs --no-index @@ -2114,6 +2121,10 @@ _git_show () " "" "${cur#*=}" return ;; + --diff-algorithm=*) + __gitcomp "$__git_diff_algorithms" "" "${cur##--diff-algorithm=}" + return + ;; --*) __gitcomp "--pretty= --format= --abbrev-commit --oneline $__git_diff_common_options diff --git a/diff.c b/diff.c index d2be77779..0724fa6ff 100644 --- a/diff.c +++ b/diff.c @@ -144,7 +144,7 @@ static int git_config_rename(const char *var, const char *value) return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0; } -static long parse_algorithm_value(const char *value) +long parse_algorithm_value(const char *value) { if (!value) return -1; @@ -3634,6 +3634,16 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac) options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF); else if (!strcmp(arg, "--histogram")) options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF); + else if (!prefixcmp(arg, "--diff-algorithm=")) { + long value = parse_algorithm_value(arg+17); + if (value < 0) + return error("option diff-algorithm accepts \"myers\", " + "\"minimal\", \"patience\" and \"histogram\""); + /* clear out previous settings */ + DIFF_XDL_CLR(options, NEED_MINIMAL); + options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK; + options->xdl_opts |= value; + } /* flags options */ else if (!strcmp(arg, "--binary")) { diff --git a/diff.h b/diff.h index a47bae48d..54c2590b4 100644 --- a/diff.h +++ b/diff.h @@ -333,6 +333,8 @@ extern struct userdiff_driver *get_textconv(struct diff_filespec *one); extern int parse_rename_score(const char **cp_p); +extern long parse_algorithm_value(const char *value); + extern int print_stat_summary(FILE *fp, int files, int insertions, int deletions); extern void setup_diff_pager(struct diff_options *); diff --git a/merge-recursive.c b/merge-recursive.c index 33ba5dc07..ea9dbd307 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -2068,6 +2068,15 @@ int parse_merge_opt(struct merge_options *o, const char *s) o->xdl_opts = DIFF_WITH_ALG(o, PATIENCE_DIFF); else if (!strcmp(s, "histogram")) o->xdl_opts = DIFF_WITH_ALG(o, HISTOGRAM_DIFF); + else if (!strcmp(s, "diff-algorithm=")) { + long value = parse_algorithm_value(s+15); + if (value < 0) + return -1; + /* clear out previous settings */ + DIFF_XDL_CLR(o, NEED_MINIMAL); + o->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK; + o->xdl_opts |= value; + } else if (!strcmp(s, "ignore-space-change")) o->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE; else if (!strcmp(s, "ignore-all-space")) -- 2.26.2