| /* |
| * 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, |
| mmfile_t *src1, const char *name1, |
| mmfile_t *src2, const char *name2, |
| int virtual_ancestor); |
| |
| 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, |
| mmfile_t *src1, const char *name1, |
| mmfile_t *src2, const char *name2, |
| int virtual_ancestor) |
| { |
| /* |
| * The tentative merge result is "ours" for the final round, |
| * or common ancestor for an internal merge. Still return |
| * "conflicted merge" status. |
| */ |
| mmfile_t *stolen = 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, |
| mmfile_t *src1, const char *name1, |
| mmfile_t *src2, const char *name2, |
| int virtual_ancestor) |
| { |
| xpparam_t xpp; |
| int style = 0; |
| |
| 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, src1, name1, |
| src2, name2, |
| virtual_ancestor); |
| } |
| |
| memset(&xpp, 0, sizeof(xpp)); |
| if (git_xmerge_style >= 0) |
| style = git_xmerge_style; |
| return xdl_merge(orig, |
| src1, name1, |
| src2, name2, |
| &xpp, XDL_MERGE_ZEALOUS | style, |
| result); |
| } |
| |
| static int ll_union_merge(const struct ll_merge_driver *drv_unused, |
| mmbuffer_t *result, |
| const char *path_unused, |
| mmfile_t *orig, |
| mmfile_t *src1, const char *name1, |
| mmfile_t *src2, const char *name2, |
| int virtual_ancestor) |
| { |
| char *src, *dst; |
| long size; |
| const int marker_size = 7; |
| int status, saved_style; |
| |
| /* We have to force the RCS "merge" style */ |
| saved_style = git_xmerge_style; |
| git_xmerge_style = 0; |
| status = ll_xdl_merge(drv_unused, result, path_unused, |
| orig, src1, NULL, src2, NULL, |
| virtual_ancestor); |
| git_xmerge_style = saved_style; |
| if (status <= 0) |
| return status; |
| size = result->size; |
| src = dst = result->ptr; |
| while (size) { |
| char ch; |
| if ((marker_size < size) && |
| (*src == '<' || *src == '=' || *src == '>')) { |
| int i; |
| ch = *src; |
| for (i = 0; i < marker_size; i++) |
| if (src[i] != ch) |
| goto not_a_marker; |
| if (src[marker_size] != '\n') |
| goto not_a_marker; |
| src += marker_size + 1; |
| size -= marker_size + 1; |
| continue; |
| } |
| not_a_marker: |
| do { |
| ch = *src++; |
| *dst++ = ch; |
| size--; |
| } while (ch != '\n' && size); |
| } |
| result->size = dst - result->ptr; |
| return 0; |
| } |
| |
| #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, |
| mmfile_t *src1, const char *name1, |
| mmfile_t *src2, const char *name2, |
| int virtual_ancestor) |
| { |
| char temp[3][50]; |
| struct strbuf cmd = STRBUF_INIT; |
| struct strbuf_expand_dict_entry dict[] = { |
| { "O", temp[0] }, |
| { "A", temp[1] }, |
| { "B", temp[2] }, |
| { NULL } |
| }; |
| const char *args[] = { "sh", "-c", NULL, NULL }; |
| int status, fd, i; |
| struct stat st; |
| |
| 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]); |
| |
| strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict); |
| |
| args[2] = cmd.buf; |
| status = run_command_v_opt(args, 0); |
| 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. |
| * |
| * 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 const char *git_path_check_merge(const char *path) |
| { |
| static struct git_attr_check attr_merge_check; |
| |
| if (!attr_merge_check.attr) |
| attr_merge_check.attr = git_attr("merge", 5); |
| |
| if (git_checkattr(path, 1, &attr_merge_check)) |
| return NULL; |
| return attr_merge_check.value; |
| } |
| |
| int ll_merge(mmbuffer_t *result_buf, |
| const char *path, |
| mmfile_t *ancestor, |
| mmfile_t *ours, const char *our_label, |
| mmfile_t *theirs, const char *their_label, |
| int virtual_ancestor) |
| { |
| const char *ll_driver_name; |
| const struct ll_merge_driver *driver; |
| |
| ll_driver_name = git_path_check_merge(path); |
| driver = find_ll_merge_driver(ll_driver_name); |
| |
| if (virtual_ancestor && driver->recursive) |
| driver = find_ll_merge_driver(driver->recursive); |
| return driver->fn(driver, result_buf, path, |
| ancestor, |
| ours, our_label, |
| theirs, their_label, virtual_ancestor); |
| } |