| /* |
| * 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 "merge-ll.h" |
| #include "quote.h" |
| #include "strbuf.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[3][50]; |
| struct strbuf cmd = STRBUF_INIT; |
| const char *format = fn->cmdline; |
| struct child_process child = CHILD_PROCESS_INIT; |
| int status, fd, i; |
| struct stat st; |
| enum ll_merge_result ret; |
| assert(opts); |
| |
| 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])); |
| |
| while (strbuf_expand_step(&cmd, &format)) { |
| if (skip_prefix(format, "%", &format)) |
| strbuf_addch(&cmd, '%'); |
| else if (skip_prefix(format, "O", &format)) |
| strbuf_addstr(&cmd, temp[0]); |
| else if (skip_prefix(format, "A", &format)) |
| strbuf_addstr(&cmd, temp[1]); |
| else if (skip_prefix(format, "B", &format)) |
| strbuf_addstr(&cmd, temp[2]); |
| else if (skip_prefix(format, "L", &format)) |
| strbuf_addf(&cmd, "%d", marker_size); |
| else if (skip_prefix(format, "P", &format)) |
| sq_quote_buf(&cmd, path); |
| else |
| strbuf_addch(&cmd, '%'); |
| } |
| |
| 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); |
| if (!status) |
| ret = LL_MERGE_OK; |
| else if (status <= 128) |
| ret = LL_MERGE_CONFLICT; |
| else |
| /* died due to a signal: WTERMSIG(status) + 128 */ |
| ret = LL_MERGE_ERROR; |
| 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, |
| const struct config_context *ctx UNUSED, |
| 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; |
| } |