diff options
Diffstat (limited to 'll-merge.c')
| -rw-r--r-- | ll-merge.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/ll-merge.c b/ll-merge.c new file mode 100644 index 0000000000..da59738c9b --- /dev/null +++ b/ll-merge.c @@ -0,0 +1,396 @@ +/* + * Low level 3-way in-core file merge. + * + * Copyright (c) 2007 Junio C Hamano + */ + +#include "cache.h" +#include "attr.h" +#include "xdiff-interface.h" +#include "run-command.h" +#include "ll-merge.h" + +struct ll_merge_driver; + +typedef int (*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; +}; + +/* + * Built-in low-levels + */ +static int ll_binary_merge(const struct ll_merge_driver *drv_unused, + mmbuffer_t *result, + const char *path_unused, + 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) +{ + mmfile_t *stolen; + assert(opts); + + /* + * The tentative merge result is "ours" for the final round, + * or common ancestor for an internal merge. Still return + * "conflicted merge" status. + */ + stolen = opts->virtual_ancestor ? orig : src1; + + result->ptr = stolen->ptr; + result->size = stolen->size; + stolen->ptr = NULL; + return 1; +} + +static int 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) +{ + xmparam_t xmp; + assert(opts); + + if (buffer_is_binary(orig->ptr, orig->size) || + buffer_is_binary(src1->ptr, src1->size) || + buffer_is_binary(src2->ptr, src2->size)) { + warning("Cannot merge binary files: %s (%s vs. %s)\n", + path, name1, name2); + 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; + return xdl_merge(orig, src1, src2, &xmp, result); +} + +static int ll_union_merge(const struct ll_merge_driver *drv_unused, + mmbuffer_t *result, + const char *path_unused, + 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_unused, + orig, NULL, src1, NULL, src2, NULL, + &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) +{ + int fd; + + strcpy(path, ".merge_file_XXXXXX"); + fd = xmkstemp(path); + if (write_in_full(fd, src->ptr, src->size) != src->size) + die_errno("unable to write temp-file"); + close(fd); +} + +/* + * User defined low-level merge driver support. + */ +static int ll_ext_merge(const struct ll_merge_driver *fn, + 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) +{ + char temp[4][50]; + struct strbuf cmd = STRBUF_INIT; + struct strbuf_expand_dict_entry dict[5]; + const char *args[] = { NULL, NULL }; + int status, fd, i; + struct stat st; + assert(opts); + + 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 = NULL; dict[4].value = NULL; + + if (fn->cmdline == NULL) + die("custom merge driver %s lacks command line.", fn->name); + + result->ptr = NULL; + result->size = 0; + create_temp(orig, temp[0]); + create_temp(src1, temp[1]); + create_temp(src2, temp[2]); + sprintf(temp[3], "%d", marker_size); + + strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict); + + args[0] = cmd.buf; + status = run_command_v_opt(args, RUN_USING_SHELL); + 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 = xmalloc(result->size + 1); + if (read_in_full(fd, result->ptr, result->size) != result->size) { + free(result->ptr); + result->ptr = NULL; + result->size = 0; + } + close_bad: + close(fd); + bad: + for (i = 0; i < 3; i++) + unlink_or_warn(temp[i]); + strbuf_release(&cmd); + return status; +} + +/* + * 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) +{ + struct ll_merge_driver *fn; + const char *ep, *name; + int namelen; + + if (!strcmp(var, "merge.default")) { + if (value) + default_ll_merge = xstrdup(value); + return 0; + } + + /* + * 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 (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5) + return 0; + + /* + * Find existing one as we might be processing merge.<name>.var2 + * after seeing merge.<name>.var1. + */ + name = var + 6; + namelen = ep - name; + for (fn = ll_user_merge; fn; fn = fn->next) + if (!strncmp(fn->name, name, namelen) && !fn->name[namelen]) + break; + if (!fn) { + fn = xcalloc(1, sizeof(struct ll_merge_driver)); + fn->name = xmemdupz(name, namelen); + fn->fn = ll_ext_merge; + *ll_user_merge_tail = fn; + ll_user_merge_tail = &(fn->next); + } + + ep++; + + if (!strcmp("name", ep)) { + if (!value) + return error("%s: lacks value", var); + fn->description = xstrdup(value); + return 0; + } + + if (!strcmp("driver", ep)) { + 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 + * + * 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", ep)) { + if (!value) + return error("%s: lacks value", var); + fn->recursive = xstrdup(value); + return 0; + } + + 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 int git_path_check_merge(const char *path, struct git_attr_check check[2]) +{ + if (!check[0].attr) { + check[0].attr = git_attr("merge"); + check[1].attr = git_attr("conflict-marker-size"); + } + return git_check_attr(path, 2, check); +} + +static void normalize_file(mmfile_t *mm, const char *path) +{ + struct strbuf strbuf = STRBUF_INIT; + if (renormalize_buffer(path, mm->ptr, mm->size, &strbuf)) { + free(mm->ptr); + mm->size = strbuf.len; + mm->ptr = strbuf_detach(&strbuf, NULL); + } +} + +int 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, + const struct ll_merge_options *opts) +{ + static struct git_attr_check check[2]; + 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); + normalize_file(ours, path); + normalize_file(theirs, path); + } + if (!git_path_check_merge(path, check)) { + ll_driver_name = check[0].value; + if (check[1].value) { + marker_size = atoi(check[1].value); + if (marker_size <= 0) + marker_size = DEFAULT_CONFLICT_MARKER_SIZE; + } + } + driver = find_ll_merge_driver(ll_driver_name); + if (opts->virtual_ancestor && driver->recursive) + driver = find_ll_merge_driver(driver->recursive); + return driver->fn(driver, result_buf, path, ancestor, ancestor_label, + ours, our_label, theirs, their_label, + opts, marker_size); +} + +int ll_merge_marker_size(const char *path) +{ + static struct git_attr_check check; + int marker_size = DEFAULT_CONFLICT_MARKER_SIZE; + + if (!check.attr) + check.attr = git_attr("conflict-marker-size"); + if (!git_check_attr(path, 1, &check) && check.value) { + marker_size = atoi(check.value); + if (marker_size <= 0) + marker_size = DEFAULT_CONFLICT_MARKER_SIZE; + } + return marker_size; +} |