merge-ll: rename from ll-merge

A long term (but rather minor) pet-peeve of mine was the name
ll-merge.[ch].  I thought it made it harder to realize what stuff was
related to merging when I was working on the merge machinery and trying
to improve it.

Further, back in d1cbe1e6d8a ("hash-ll.h: split out of hash.h to remove
dependency on repository.h", 2023-04-22), we have split the portions of
hash.h that do not depend upon repository.h into a "hash-ll.h" (due to
the recommendation to use "ll" for "low-level" in its name[1], but which
I used as a suffix precisely because of my distaste for "ll-merge").
When we discussed adding additional "*-ll.h" files, a request was made
that we use "ll" consistently as either a prefix or a suffix.  Since it
is already in use as both a prefix and a suffix, the only way to do so
is to rename some files.

Besides my distaste for the ll-merge.[ch] name, let me also note that
the files
  ll-fsmonitor.h, ll-hash.h, ll-merge.h, ll-object-store.h, ll-read-cache.h
would have essentially nothing to do with each other and make no sense
to group.  But giving them the common "ll-" prefix would group them.  Using
"-ll" as a suffix thus seems just much more logical to me.  Rename
ll-merge.[ch] to merge-ll.[ch] to achieve this consistency, and to
ensure we get a more logical grouping of files.

[1] https://lore.kernel.org/git/kl6lsfcu1g8w.fsf@chooglen-macbookpro.roam.corp.google.com/

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 0 insertions, 432 deletions

diff --git a/ll-merge.c b/ll-merge.c
deleted file mode 100644
index 07ec16e8e5..0000000000
--- a/ll-merge.c
+++ /dev/null
@@ -1,432 +0,0 @@
-/*
- * Low level 3-way in-core file merge.
- *
- * Copyright (c) 2007 Junio C Hamano
- */
-
-#include "git-compat-util.h"
-#include "config.h"
-#include "convert.h"
-#include "attr.h"
-#include "xdiff-interface.h"
-#include "run-command.h"
-#include "ll-merge.h"
-#include "quote.h"
-#include "strbuf.h"
-#include "wrapper.h"
-
-struct ll_merge_driver;
-
-typedef enum ll_merge_result (*ll_merge_fn)(const struct ll_merge_driver *,
-			   mmbuffer_t *result,
-			   const char *path,
-			   mmfile_t *orig, const char *orig_name,
-			   mmfile_t *src1, const char *name1,
-			   mmfile_t *src2, const char *name2,
-			   const struct ll_merge_options *opts,
-			   int marker_size);
-
-struct ll_merge_driver {
-	const char *name;
-	const char *description;
-	ll_merge_fn fn;
-	const char *recursive;
-	struct ll_merge_driver *next;
-	char *cmdline;
-};
-
-static struct attr_check *merge_attributes;
-static struct attr_check *load_merge_attributes(void)
-{
-	if (!merge_attributes)
-		merge_attributes = attr_check_initl("merge", "conflict-marker-size", NULL);
-	return merge_attributes;
-}
-
-void reset_merge_attributes(void)
-{
-	attr_check_free(merge_attributes);
-	merge_attributes = NULL;
-}
-
-/*
- * Built-in low-levels
- */
-static enum ll_merge_result ll_binary_merge(const struct ll_merge_driver *drv UNUSED,
-			   mmbuffer_t *result,
-			   const char *path UNUSED,
-			   mmfile_t *orig, const char *orig_name UNUSED,
-			   mmfile_t *src1, const char *name1 UNUSED,
-			   mmfile_t *src2, const char *name2 UNUSED,
-			   const struct ll_merge_options *opts,
-			   int marker_size UNUSED)
-{
-	enum ll_merge_result ret;
-	mmfile_t *stolen;
-	assert(opts);
-
-	/*
-	 * The tentative merge result is the common ancestor for an
-	 * internal merge.  For the final merge, it is "ours" by
-	 * default but -Xours/-Xtheirs can tweak the choice.
-	 */
-	if (opts->virtual_ancestor) {
-		stolen = orig;
-		ret = LL_MERGE_OK;
-	} else {
-		switch (opts->variant) {
-		default:
-			ret = LL_MERGE_BINARY_CONFLICT;
-			stolen = src1;
-			break;
-		case XDL_MERGE_FAVOR_OURS:
-			ret = LL_MERGE_OK;
-			stolen = src1;
-			break;
-		case XDL_MERGE_FAVOR_THEIRS:
-			ret = LL_MERGE_OK;
-			stolen = src2;
-			break;
-		}
-	}
-
-	result->ptr = stolen->ptr;
-	result->size = stolen->size;
-	stolen->ptr = NULL;
-
-	return ret;
-}
-
-static enum ll_merge_result ll_xdl_merge(const struct ll_merge_driver *drv_unused,
-			mmbuffer_t *result,
-			const char *path,
-			mmfile_t *orig, const char *orig_name,
-			mmfile_t *src1, const char *name1,
-			mmfile_t *src2, const char *name2,
-			const struct ll_merge_options *opts,
-			int marker_size)
-{
-	enum ll_merge_result ret;
-	xmparam_t xmp;
-	int status;
-	assert(opts);
-
-	if (orig->size > MAX_XDIFF_SIZE ||
-	    src1->size > MAX_XDIFF_SIZE ||
-	    src2->size > MAX_XDIFF_SIZE ||
-	    buffer_is_binary(orig->ptr, orig->size) ||
-	    buffer_is_binary(src1->ptr, src1->size) ||
-	    buffer_is_binary(src2->ptr, src2->size)) {
-		return ll_binary_merge(drv_unused, result,
-				       path,
-				       orig, orig_name,
-				       src1, name1,
-				       src2, name2,
-				       opts, marker_size);
-	}
-
-	memset(&xmp, 0, sizeof(xmp));
-	xmp.level = XDL_MERGE_ZEALOUS;
-	xmp.favor = opts->variant;
-	xmp.xpp.flags = opts->xdl_opts;
-	if (git_xmerge_style >= 0)
-		xmp.style = git_xmerge_style;
-	if (marker_size > 0)
-		xmp.marker_size = marker_size;
-	xmp.ancestor = orig_name;
-	xmp.file1 = name1;
-	xmp.file2 = name2;
-	status = xdl_merge(orig, src1, src2, &xmp, result);
-	ret = (status > 0) ? LL_MERGE_CONFLICT : status;
-	return ret;
-}
-
-static enum ll_merge_result ll_union_merge(const struct ll_merge_driver *drv_unused,
-			  mmbuffer_t *result,
-			  const char *path,
-			  mmfile_t *orig, const char *orig_name,
-			  mmfile_t *src1, const char *name1,
-			  mmfile_t *src2, const char *name2,
-			  const struct ll_merge_options *opts,
-			  int marker_size)
-{
-	/* Use union favor */
-	struct ll_merge_options o;
-	assert(opts);
-	o = *opts;
-	o.variant = XDL_MERGE_FAVOR_UNION;
-	return ll_xdl_merge(drv_unused, result, path,
-			    orig, orig_name, src1, name1, src2, name2,
-			    &o, marker_size);
-}
-
-#define LL_BINARY_MERGE 0
-#define LL_TEXT_MERGE 1
-#define LL_UNION_MERGE 2
-static struct ll_merge_driver ll_merge_drv[] = {
-	{ "binary", "built-in binary merge", ll_binary_merge },
-	{ "text", "built-in 3-way text merge", ll_xdl_merge },
-	{ "union", "built-in union merge", ll_union_merge },
-};
-
-static void create_temp(mmfile_t *src, char *path, size_t len)
-{
-	int fd;
-
-	xsnprintf(path, len, ".merge_file_XXXXXX");
-	fd = xmkstemp(path);
-	if (write_in_full(fd, src->ptr, src->size) < 0)
-		die_errno("unable to write temp-file");
-	close(fd);
-}
-
-/*
- * User defined low-level merge driver support.
- */
-static enum ll_merge_result ll_ext_merge(const struct ll_merge_driver *fn,
-			mmbuffer_t *result,
-			const char *path,
-			mmfile_t *orig, const char *orig_name UNUSED,
-			mmfile_t *src1, const char *name1 UNUSED,
-			mmfile_t *src2, const char *name2 UNUSED,
-			const struct ll_merge_options *opts,
-			int marker_size)
-{
-	char temp[4][50];
-	struct strbuf cmd = STRBUF_INIT;
-	struct strbuf_expand_dict_entry dict[6];
-	struct strbuf path_sq = STRBUF_INIT;
-	struct child_process child = CHILD_PROCESS_INIT;
-	int status, fd, i;
-	struct stat st;
-	enum ll_merge_result ret;
-	assert(opts);
-
-	sq_quote_buf(&path_sq, path);
-	dict[0].placeholder = "O"; dict[0].value = temp[0];
-	dict[1].placeholder = "A"; dict[1].value = temp[1];
-	dict[2].placeholder = "B"; dict[2].value = temp[2];
-	dict[3].placeholder = "L"; dict[3].value = temp[3];
-	dict[4].placeholder = "P"; dict[4].value = path_sq.buf;
-	dict[5].placeholder = NULL; dict[5].value = NULL;
-
-	if (!fn->cmdline)
-		die("custom merge driver %s lacks command line.", fn->name);
-
-	result->ptr = NULL;
-	result->size = 0;
-	create_temp(orig, temp[0], sizeof(temp[0]));
-	create_temp(src1, temp[1], sizeof(temp[1]));
-	create_temp(src2, temp[2], sizeof(temp[2]));
-	xsnprintf(temp[3], sizeof(temp[3]), "%d", marker_size);
-
-	strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict);
-
-	child.use_shell = 1;
-	strvec_push(&child.args, cmd.buf);
-	status = run_command(&child);
-	fd = open(temp[1], O_RDONLY);
-	if (fd < 0)
-		goto bad;
-	if (fstat(fd, &st))
-		goto close_bad;
-	result->size = st.st_size;
-	result->ptr = xmallocz(result->size);
-	if (read_in_full(fd, result->ptr, result->size) != result->size) {
-		FREE_AND_NULL(result->ptr);
-		result->size = 0;
-	}
- close_bad:
-	close(fd);
- bad:
-	for (i = 0; i < 3; i++)
-		unlink_or_warn(temp[i]);
-	strbuf_release(&cmd);
-	strbuf_release(&path_sq);
-	ret = (status > 0) ? LL_MERGE_CONFLICT : status;
-	return ret;
-}
-
-/*
- * merge.default and merge.driver configuration items
- */
-static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
-static const char *default_ll_merge;
-
-static int read_merge_config(const char *var, const char *value,
-			     void *cb UNUSED)
-{
-	struct ll_merge_driver *fn;
-	const char *key, *name;
-	size_t namelen;
-
-	if (!strcmp(var, "merge.default"))
-		return git_config_string(&default_ll_merge, var, value);
-
-	/*
-	 * We are not interested in anything but "merge.<name>.variable";
-	 * especially, we do not want to look at variables such as
-	 * "merge.summary", "merge.tool", and "merge.verbosity".
-	 */
-	if (parse_config_key(var, "merge", &name, &namelen, &key) < 0 || !name)
-		return 0;
-
-	/*
-	 * Find existing one as we might be processing merge.<name>.var2
-	 * after seeing merge.<name>.var1.
-	 */
-	for (fn = ll_user_merge; fn; fn = fn->next)
-		if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
-			break;
-	if (!fn) {
-		CALLOC_ARRAY(fn, 1);
-		fn->name = xmemdupz(name, namelen);
-		fn->fn = ll_ext_merge;
-		*ll_user_merge_tail = fn;
-		ll_user_merge_tail = &(fn->next);
-	}
-
-	if (!strcmp("name", key))
-		return git_config_string(&fn->description, var, value);
-
-	if (!strcmp("driver", key)) {
-		if (!value)
-			return error("%s: lacks value", var);
-		/*
-		 * merge.<name>.driver specifies the command line:
-		 *
-		 *	command-line
-		 *
-		 * The command-line will be interpolated with the following
-		 * tokens and is given to the shell:
-		 *
-		 *    %O - temporary file name for the merge base.
-		 *    %A - temporary file name for our version.
-		 *    %B - temporary file name for the other branches' version.
-		 *    %L - conflict marker length
-		 *    %P - the original path (safely quoted for the shell)
-		 *
-		 * The external merge driver should write the results in the
-		 * file named by %A, and signal that it has done with zero exit
-		 * status.
-		 */
-		fn->cmdline = xstrdup(value);
-		return 0;
-	}
-
-	if (!strcmp("recursive", key))
-		return git_config_string(&fn->recursive, var, value);
-
-	return 0;
-}
-
-static void initialize_ll_merge(void)
-{
-	if (ll_user_merge_tail)
-		return;
-	ll_user_merge_tail = &ll_user_merge;
-	git_config(read_merge_config, NULL);
-}
-
-static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
-{
-	struct ll_merge_driver *fn;
-	const char *name;
-	int i;
-
-	initialize_ll_merge();
-
-	if (ATTR_TRUE(merge_attr))
-		return &ll_merge_drv[LL_TEXT_MERGE];
-	else if (ATTR_FALSE(merge_attr))
-		return &ll_merge_drv[LL_BINARY_MERGE];
-	else if (ATTR_UNSET(merge_attr)) {
-		if (!default_ll_merge)
-			return &ll_merge_drv[LL_TEXT_MERGE];
-		else
-			name = default_ll_merge;
-	}
-	else
-		name = merge_attr;
-
-	for (fn = ll_user_merge; fn; fn = fn->next)
-		if (!strcmp(fn->name, name))
-			return fn;
-
-	for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
-		if (!strcmp(ll_merge_drv[i].name, name))
-			return &ll_merge_drv[i];
-
-	/* default to the 3-way */
-	return &ll_merge_drv[LL_TEXT_MERGE];
-}
-
-static void normalize_file(mmfile_t *mm, const char *path, struct index_state *istate)
-{
-	struct strbuf strbuf = STRBUF_INIT;
-	if (renormalize_buffer(istate, path, mm->ptr, mm->size, &strbuf)) {
-		free(mm->ptr);
-		mm->size = strbuf.len;
-		mm->ptr = strbuf_detach(&strbuf, NULL);
-	}
-}
-
-enum ll_merge_result ll_merge(mmbuffer_t *result_buf,
-	     const char *path,
-	     mmfile_t *ancestor, const char *ancestor_label,
-	     mmfile_t *ours, const char *our_label,
-	     mmfile_t *theirs, const char *their_label,
-	     struct index_state *istate,
-	     const struct ll_merge_options *opts)
-{
-	struct attr_check *check = load_merge_attributes();
-	static const struct ll_merge_options default_opts;
-	const char *ll_driver_name = NULL;
-	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
-	const struct ll_merge_driver *driver;
-
-	if (!opts)
-		opts = &default_opts;
-
-	if (opts->renormalize) {
-		normalize_file(ancestor, path, istate);
-		normalize_file(ours, path, istate);
-		normalize_file(theirs, path, istate);
-	}
-
-	git_check_attr(istate, path, check);
-	ll_driver_name = check->items[0].value;
-	if (check->items[1].value) {
-		marker_size = atoi(check->items[1].value);
-		if (marker_size <= 0)
-			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
-	}
-	driver = find_ll_merge_driver(ll_driver_name);
-
-	if (opts->virtual_ancestor) {
-		if (driver->recursive)
-			driver = find_ll_merge_driver(driver->recursive);
-	}
-	if (opts->extra_marker_size) {
-		marker_size += opts->extra_marker_size;
-	}
-	return driver->fn(driver, result_buf, path, ancestor, ancestor_label,
-			  ours, our_label, theirs, their_label,
-			  opts, marker_size);
-}
-
-int ll_merge_marker_size(struct index_state *istate, const char *path)
-{
-	static struct attr_check *check;
-	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
-
-	if (!check)
-		check = attr_check_initl("conflict-marker-size", NULL);
-	git_check_attr(istate, path, check);
-	if (check->items[0].value) {
-		marker_size = atoi(check->items[0].value);
-		if (marker_size <= 0)
-			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
-	}
-	return marker_size;
-}