Merge branch 'ab/pickaxe-pcre2'

Rewrite the backend for "diff -G/-S" to use pcre2 engine when
available.

* ab/pickaxe-pcre2: (22 commits)
  xdiff-interface: replace discard_hunk_line() with a flag
  xdiff users: use designated initializers for out_line
  pickaxe -G: don't special-case create/delete
  pickaxe -G: terminate early on matching lines
  xdiff-interface: allow early return from xdiff_emit_line_fn
  xdiff-interface: prepare for allowing early return
  pickaxe -S: slightly optimize contains()
  pickaxe: rename variables in has_changes() for brevity
  pickaxe -S: support content with NULs under --pickaxe-regex
  pickaxe: assert that we must have a needle under -G or -S
  pickaxe: refactor function selection in diffcore-pickaxe()
  perf: add performance test for pickaxe
  pickaxe/style: consolidate declarations and assignments
  diff.h: move pickaxe fields together again
  pickaxe: die when --find-object and --pickaxe-all are combined
  pickaxe: die when -G and --pickaxe-regex are combined
  pickaxe tests: add missing test for --no-pickaxe-regex being an error
  pickaxe tests: test for -G, -S and --find-object incompatibility
  pickaxe tests: add test for "log -S" not being a regex
  pickaxe tests: add test for diffgrep_consume() internals
  ...

builtin/merge-tree.c

@@ -107,15 +107,12 @@ static void show_diff(struct merge_list *entry)
 	mmfile_t src, dst;
 	xpparam_t xpp;
 	xdemitconf_t xecfg;
-	xdemitcb_t ecb;
+	xdemitcb_t ecb = { .out_line = show_outf };
 
 	memset(&xpp, 0, sizeof(xpp));
 	xpp.flags = 0;
 	memset(&xecfg, 0, sizeof(xecfg));
 	xecfg.ctxlen = 3;
-	ecb.out_hunk = NULL;
-	ecb.out_line = show_outf;
-	ecb.priv = NULL;
 
 	src.ptr = origin(entry, &size);
 	if (!src.ptr)

builtin/rerere.c

@@ -28,7 +28,7 @@ static int diff_two(const char *file1, const char *label1,
 {
 	xpparam_t xpp;
 	xdemitconf_t xecfg;
-	xdemitcb_t ecb;
+	xdemitcb_t ecb = { .out_line = outf };
 	mmfile_t minus, plus;
 	int ret;
 
@@ -41,8 +41,6 @@ static int diff_two(const char *file1, const char *label1,
 	xpp.flags = 0;
 	memset(&xecfg, 0, sizeof(xecfg));
 	xecfg.ctxlen = 3;
-	ecb.out_hunk = NULL;
-	ecb.out_line = outf;
 	ret = xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 
 	free(minus.ptr);

combine-diff.c

@@ -403,11 +403,11 @@ static void consume_hunk(void *state_,
 	state->sline[state->nb-1].p_lno[state->n] = state->ob;
 }
 
-static void consume_line(void *state_, char *line, unsigned long len)
+static int consume_line(void *state_, char *line, unsigned long len)
 {
 	struct combine_diff_state *state = state_;
 	if (!state->lost_bucket)
-		return; /* not in any hunk yet */
+		return 0; /* not in any hunk yet */
 	switch (line[0]) {
 	case '-':
 		append_lost(state->lost_bucket, state->n, line+1, len-1);
@@ -417,6 +417,7 @@ static void consume_line(void *state_, char *line, unsigned long len)
 		state->lno++;
 		break;
 	}
+	return 0;
 }
 
 static void combine_diff(struct repository *r,

diff.c

@@ -2340,7 +2340,7 @@ static void find_lno(const char *line, struct emit_callback *ecbdata)
 	ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 }
 
-static void fn_out_consume(void *priv, char *line, unsigned long len)
+static int fn_out_consume(void *priv, char *line, unsigned long len)
 {
 	struct emit_callback *ecbdata = priv;
 	struct diff_options *o = ecbdata->opt;
@@ -2376,7 +2376,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 		len = sane_truncate_line(line, len);
 		find_lno(line, ecbdata);
 		emit_hunk_header(ecbdata, line, len);
-		return;
+		return 0;
 	}
 
 	if (ecbdata->diff_words) {
@@ -2386,11 +2386,11 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 		if (line[0] == '-') {
 			diff_words_append(line, len,
 					  &ecbdata->diff_words->minus);
-			return;
+			return 0;
 		} else if (line[0] == '+') {
 			diff_words_append(line, len,
 					  &ecbdata->diff_words->plus);
-			return;
+			return 0;
 		} else if (starts_with(line, "\\ ")) {
 			/*
 			 * Eat the "no newline at eof" marker as if we
@@ -2399,11 +2399,11 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 			 * defer processing. If this is the end of
 			 * preimage, more "+" lines may come after it.
 			 */
-			return;
+			return 0;
 		}
 		diff_words_flush(ecbdata);
 		emit_diff_symbol(o, s, line, len, 0);
-		return;
+		return 0;
 	}
 
 	switch (line[0]) {
@@ -2427,6 +2427,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 				 line, len, 0);
 		break;
 	}
+	return 0;
 }
 
 static void pprint_rename(struct strbuf *name, const char *a, const char *b)
@@ -2526,7 +2527,7 @@ static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 	return x;
 }
 
-static void diffstat_consume(void *priv, char *line, unsigned long len)
+static int diffstat_consume(void *priv, char *line, unsigned long len)
 {
 	struct diffstat_t *diffstat = priv;
 	struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
@@ -2535,6 +2536,7 @@ static void diffstat_consume(void *priv, char *line, unsigned long len)
 		x->added++;
 	else if (line[0] == '-')
 		x->deleted++;
+	return 0;
 }
 
 const char mime_boundary_leader[] = "------------";
@@ -3212,7 +3214,7 @@ static void checkdiff_consume_hunk(void *priv,
 	data->lineno = nb - 1;
 }
 
-static void checkdiff_consume(void *priv, char *line, unsigned long len)
+static int checkdiff_consume(void *priv, char *line, unsigned long len)
 {
 	struct checkdiff_t *data = priv;
 	int marker_size = data->conflict_marker_size;
@@ -3236,7 +3238,7 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
 		}
 		bad = ws_check(line + 1, len - 1, data->ws_rule);
 		if (!bad)
-			return;
+			return 0;
 		data->status |= bad;
 		err = whitespace_error_string(bad);
 		fprintf(data->o->file, "%s%s:%d: %s.\n",
@@ -3248,6 +3250,7 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
 	} else if (line[0] == ' ') {
 		data->lineno++;
 	}
+	return 0;
 }
 
 static unsigned char *deflate_it(char *data,
@@ -3726,7 +3729,8 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
 		xpp.anchors_nr = o->anchors_nr;
 		xecfg.ctxlen = o->context;
 		xecfg.interhunkctxlen = o->interhunkcontext;
-		if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
+		xecfg.flags = XDL_EMIT_NO_HUNK_HDR;
+		if (xdi_diff_outf(&mf1, &mf2, NULL,
 				  diffstat_consume, diffstat, &xpp, &xecfg))
 			die("unable to generate diffstat for %s", one->path);
 
@@ -4632,6 +4636,12 @@ void diff_setup_done(struct diff_options *options)
 	if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
 		die(_("-G, -S and --find-object are mutually exclusive"));
 
+	if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_G_REGEX_MASK))
+		die(_("-G and --pickaxe-regex are mutually exclusive, use --pickaxe-regex with -S"));
+
+	if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_ALL_OBJFIND_MASK))
+		die(_("---pickaxe-all and --find-object are mutually exclusive, use --pickaxe-all with -G and -S"));
+
 	/*
 	 * Most of the time we can say "there are changes"
 	 * only by checking if there are changed paths, but
@@ -6119,17 +6129,18 @@ void flush_one_hunk(struct object_id *result, git_hash_ctx *ctx)
 	}
 }
 
-static void patch_id_consume(void *priv, char *line, unsigned long len)
+static int patch_id_consume(void *priv, char *line, unsigned long len)
 {
 	struct patch_id_t *data = priv;
 	int new_len;
 
 	if (len > 12 && starts_with(line, "\\ "))
-		return;
+		return 0;
 	new_len = remove_space(line, len);
 
 	the_hash_algo->update_fn(data->ctx, line, new_len);
 	data->patchlen += new_len;
+	return 0;
 }
 
 static void patch_id_add_string(git_hash_ctx *ctx, const char *str)
@@ -6227,8 +6238,8 @@ static int diff_get_patch_id(struct diff_options *options, struct object_id *oid
 
 		xpp.flags = 0;
 		xecfg.ctxlen = 3;
-		xecfg.flags = 0;
-		if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
+		xecfg.flags = XDL_EMIT_NO_HUNK_HDR;
+		if (xdi_diff_outf(&mf1, &mf2, NULL,
 				  patch_id_consume, &data, &xpp, &xecfg))
 			return error("unable to generate patch-id diff for %s",
 				     p->one->path);

diff.h

@@ -265,6 +265,7 @@ struct diff_options {
 	 * postimage of the diff_queue.
 	 */
 	const char *pickaxe;
+	unsigned pickaxe_opts;
 
 	/* -I<regex> */
 	regex_t **ignore_regex;
@@ -304,8 +305,6 @@ struct diff_options {
 	/* The output format used when `diff_flush()` is run. */
 	int output_format;
 
-	unsigned pickaxe_opts;
-
 	/* Affects the way detection logic for complete rewrites, renames and
 	 * copies.
 	 */
@@ -556,6 +555,10 @@ int git_config_rename(const char *var, const char *value);
 #define DIFF_PICKAXE_KINDS_MASK (DIFF_PICKAXE_KIND_S | \
 				 DIFF_PICKAXE_KIND_G | \
 				 DIFF_PICKAXE_KIND_OBJFIND)
+#define DIFF_PICKAXE_KINDS_G_REGEX_MASK (DIFF_PICKAXE_KIND_G | \
+					 DIFF_PICKAXE_REGEX)
+#define DIFF_PICKAXE_KINDS_ALL_OBJFIND_MASK (DIFF_PICKAXE_ALL | \
+					     DIFF_PICKAXE_KIND_OBJFIND)
 
 #define DIFF_PICKAXE_IGNORE_CASE	32