diff options
| -rw-r--r-- | Documentation/diff-config.txt | 5 | ||||
| -rw-r--r-- | Documentation/diff-options.txt | 6 | ||||
| -rw-r--r-- | diff.c | 11 | ||||
| -rw-r--r-- | xdiff/xdiff.h | 2 | ||||
| -rw-r--r-- | xdiff/xdiffi.c | 26 |
5 files changed, 50 insertions, 0 deletions
diff --git a/Documentation/diff-config.txt b/Documentation/diff-config.txt index 6eaa45271c..9bf3e923cf 100644 --- a/Documentation/diff-config.txt +++ b/Documentation/diff-config.txt @@ -166,6 +166,11 @@ diff.tool:: include::mergetools-diff.txt[] +diff.compactionHeuristic:: + Set this option to enable an experimental heuristic that + shifts the hunk boundary in an attempt to make the resulting + patch easier to read. + diff.algorithm:: Choose a diff algorithm. The variants are as follows: + diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt index 3ad6404dbc..b513023cd7 100644 --- a/Documentation/diff-options.txt +++ b/Documentation/diff-options.txt @@ -63,6 +63,12 @@ ifndef::git-format-patch[] Synonym for `-p --raw`. endif::git-format-patch[] +--compaction-heuristic:: +--no-compaction-heuristic:: + These are to help debugging and tuning an experimental + heuristic that shifts the hunk boundary in an attempt to + make the resulting patch easier to read. + --minimal:: Spend extra time to make sure the smallest possible diff is produced. @@ -25,6 +25,7 @@ #endif static int diff_detect_rename_default; +static int diff_compaction_heuristic = 1; static int diff_rename_limit_default = 400; static int diff_suppress_blank_empty; static int diff_use_color_default = -1; @@ -183,6 +184,10 @@ int git_diff_ui_config(const char *var, const char *value, void *cb) diff_detect_rename_default = git_config_rename(var, value); return 0; } + if (!strcmp(var, "diff.compactionheuristic")) { + diff_compaction_heuristic = git_config_bool(var, value); + return 0; + } if (!strcmp(var, "diff.autorefreshindex")) { diff_auto_refresh_index = git_config_bool(var, value); return 0; @@ -3235,6 +3240,8 @@ void diff_setup(struct diff_options *options) options->use_color = diff_use_color_default; options->detect_rename = diff_detect_rename_default; options->xdl_opts |= diff_algorithm; + if (diff_compaction_heuristic) + DIFF_XDL_SET(options, COMPACTION_HEURISTIC); options->orderfile = diff_order_file_cfg; @@ -3712,6 +3719,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac) DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL); else if (!strcmp(arg, "--ignore-blank-lines")) DIFF_XDL_SET(options, IGNORE_BLANK_LINES); + else if (!strcmp(arg, "--compaction-heuristic")) + DIFF_XDL_SET(options, COMPACTION_HEURISTIC); + else if (!strcmp(arg, "--no-compaction-heuristic")) + DIFF_XDL_CLR(options, COMPACTION_HEURISTIC); else if (!strcmp(arg, "--patience")) options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF); else if (!strcmp(arg, "--histogram")) diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h index c0339919cc..d1dbb2750a 100644 --- a/xdiff/xdiff.h +++ b/xdiff/xdiff.h @@ -41,6 +41,8 @@ extern "C" { #define XDF_IGNORE_BLANK_LINES (1 << 7) +#define XDF_COMPACTION_HEURISTIC (1 << 8) + #define XDL_EMIT_FUNCNAMES (1 << 0) #define XDL_EMIT_COMMON (1 << 1) #define XDL_EMIT_FUNCCONTEXT (1 << 2) diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c index 748eeb9919..b3c6848875 100644 --- a/xdiff/xdiffi.c +++ b/xdiff/xdiffi.c @@ -400,6 +400,11 @@ static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1, } +static int is_blank_line(xrecord_t **recs, long ix, long flags) +{ + return xdl_blankline(recs[ix]->ptr, recs[ix]->size, flags); +} + static int recs_match(xrecord_t **recs, long ixs, long ix, long flags) { return (recs[ixs]->ha == recs[ix]->ha && @@ -411,6 +416,7 @@ static int recs_match(xrecord_t **recs, long ixs, long ix, long flags) int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) { long ix, ixo, ixs, ixref, grpsiz, nrec = xdf->nrec; char *rchg = xdf->rchg, *rchgo = xdfo->rchg; + unsigned int blank_lines; xrecord_t **recs = xdf->recs; /* @@ -444,6 +450,7 @@ int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) { do { grpsiz = ix - ixs; + blank_lines = 0; /* * If the line before the current change group, is equal to @@ -478,6 +485,8 @@ int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) { * the group. */ while (ix < nrec && recs_match(recs, ixs, ix, flags)) { + blank_lines += is_blank_line(recs, ix, flags); + rchg[ixs++] = 0; rchg[ix++] = 1; @@ -504,6 +513,23 @@ int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) { rchg[--ix] = 0; while (rchgo[--ixo]); } + + /* + * If a group can be moved back and forth, see if there is a + * blank line in the moving space. If there is a blank line, + * make sure the last blank line is the end of the group. + * + * As we already shifted the group forward as far as possible + * in the earlier loop, we need to shift it back only if at all. + */ + if ((flags & XDF_COMPACTION_HEURISTIC) && blank_lines) { + while (ixs > 0 && + !is_blank_line(recs, ix - 1, flags) && + recs_match(recs, ixs - 1, ix - 1, flags)) { + rchg[--ixs] = 1; + rchg[--ix] = 0; + } + } } return 0; |