/* * "git difftool" builtin command * * This is a wrapper around the GIT_EXTERNAL_DIFF-compatible * git-difftool--helper script. * * This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git. * The GIT_DIFF* variables are exported for use by git-difftool--helper. * * Any arguments that are unknown to this script are forwarded to 'git diff'. * * Copyright (C) 2016 Johannes Schindelin */ #include "cache.h" #include "config.h" #include "builtin.h" #include "run-command.h" #include "exec-cmd.h" #include "parse-options.h" #include "argv-array.h" #include "strbuf.h" #include "lockfile.h" #include "object-store.h" #include "dir.h" static char *diff_gui_tool; static int trust_exit_code; static const char *const builtin_difftool_usage[] = { N_("git difftool [<options>] [<commit> [<commit>]] [--] [<path>...]"), NULL }; static int difftool_config(const char *var, const char *value, void *cb) { if (!strcmp(var, "diff.guitool")) { diff_gui_tool = xstrdup(value); return 0; } if (!strcmp(var, "difftool.trustexitcode")) { trust_exit_code = git_config_bool(var, value); return 0; } return git_default_config(var, value, cb); } static int print_tool_help(void) { const char *argv[] = { "mergetool", "--tool-help=diff", NULL }; return run_command_v_opt(argv, RUN_GIT_CMD); } static int parse_index_info(char *p, int *mode1, int *mode2, struct object_id *oid1, struct object_id *oid2, char *status) { if (*p != ':') return error("expected ':', got '%c'", *p); *mode1 = (int)strtol(p + 1, &p, 8); if (*p != ' ') return error("expected ' ', got '%c'", *p); *mode2 = (int)strtol(p + 1, &p, 8); if (*p != ' ') return error("expected ' ', got '%c'", *p); if (get_oid_hex(++p, oid1)) return error("expected object ID, got '%s'", p + 1); p += GIT_SHA1_HEXSZ; if (*p != ' ') return error("expected ' ', got '%c'", *p); if (get_oid_hex(++p, oid2)) return error("expected object ID, got '%s'", p + 1); p += GIT_SHA1_HEXSZ; if (*p != ' ') return error("expected ' ', got '%c'", *p); *status = *++p; if (!*status) return error("missing status"); if (p[1] && !isdigit(p[1])) return error("unexpected trailer: '%s'", p + 1); return 0; } /* * Remove any trailing slash from $workdir * before starting to avoid double slashes in symlink targets. */ static void add_path(struct strbuf *buf, size_t base_len, const char *path) { strbuf_setlen(buf, base_len); if (buf->len && buf->buf[buf->len - 1] != '/') strbuf_addch(buf, '/'); strbuf_addstr(buf, path); } /* * Determine whether we can simply reuse the file in the worktree. */ static int use_wt_file(const char *workdir, const char *name, struct object_id *oid) { struct strbuf buf = STRBUF_INIT; struct stat st; int use = 0; strbuf_addstr(&buf, workdir); add_path(&buf, buf.len, name); if (!lstat(buf.buf, &st) && !S_ISLNK(st.st_mode)) { struct object_id wt_oid; int fd = open(buf.buf, O_RDONLY); if (fd >= 0 && !index_fd(&the_index, &wt_oid, fd, &st, OBJ_BLOB, name, 0)) { if (is_null_oid(oid)) { oidcpy(oid, &wt_oid); use = 1; } else if (oideq(oid, &wt_oid)) use = 1; } } strbuf_release(&buf); return use; } struct working_tree_entry { struct hashmap_entry entry; char path[FLEX_ARRAY]; }; static int working_tree_entry_cmp(const void *unused_cmp_data, const void *entry, const void *entry_or_key, const void *unused_keydata) { const struct working_tree_entry *a = entry; const struct working_tree_entry *b = entry_or_key; return strcmp(a->path, b->path); } /* * The `left` and `right` entries hold paths for the symlinks hashmap, * and a SHA-1 surrounded by brief text for submodules. */ struct pair_entry { struct hashmap_entry entry; char left[PATH_MAX], right[PATH_MAX]; const char path[FLEX_ARRAY]; }; static int pair_cmp(const void *unused_cmp_data, const void *entry, const void *entry_or_key, const void *unused_keydata) { const struct pair_entry *a = entry; const struct pair_entry *b = entry_or_key; return strcmp(a->path, b->path); } static void add_left_or_right(struct hashmap *map, const char *path, const char *content, int is_right) { struct pair_entry *e, *existing; FLEX_ALLOC_STR(e, path, path); hashmap_entry_init(e, strhash(path)); existing = hashmap_get(map, e, NULL); if (existing) { free(e); e = existing; } else { e->left[0] = e->right[0] = '\0'; hashmap_add(map, e); } strlcpy(is_right ? e->right : e->left, content, PATH_MAX); } struct path_entry { struct hashmap_entry entry; char path[FLEX_ARRAY]; }; static int path_entry_cmp(const void *unused_cmp_data, const void *entry, const void *entry_or_key, const void *key) { const struct path_entry *a = entry; const struct path_entry *b = entry_or_key; return strcmp(a->path, key ? key : b->path); } static void changed_files(struct hashmap *result, const char *index_path, const char *workdir) { struct child_process update_index = CHILD_PROCESS_INIT; struct child_process diff_files = CHILD_PROCESS_INIT; struct strbuf index_env = STRBUF_INIT, buf = STRBUF_INIT; const char *git_dir = absolute_path(get_git_dir()), *env[] = { NULL, NULL }; FILE *fp; strbuf_addf(&index_env, "GIT_INDEX_FILE=%s", index_path); env[0] = index_env.buf; argv_array_pushl(&update_index.args, "--git-dir", git_dir, "--work-tree", workdir, "update-index", "--really-refresh", "-q", "--unmerged", NULL); update_index.no_stdin = 1; update_index.no_stdout = 1; update_index.no_stderr = 1; update_index.git_cmd = 1; update_index.use_shell = 0; update_index.clean_on_exit = 1; update_index.dir = workdir; update_index.env = env; /* Ignore any errors of update-index */ run_command(&update_index); argv_array_pushl(&diff_files.args, "--git-dir", git_dir, "--work-tree", workdir, "diff-files", "--name-only", "-z", NULL); diff_files.no_stdin = 1; diff_files.git_cmd = 1; diff_files.use_shell = 0; diff_files.clean_on_exit = 1; diff_files.out = -1; diff_files.dir = workdir; diff_files.env = env; if (start_command(&diff_files)) die("could not obtain raw diff"); fp = xfdopen(diff_files.out, "r"); while (!strbuf_getline_nul(&buf, fp)) { struct path_entry *entry; FLEX_ALLOC_STR(entry, path, buf.buf); hashmap_entry_init(entry, strhash(buf.buf)); hashmap_add(result, entry); } fclose(fp); if (finish_command(&diff_files)) die("diff-files did not exit properly"); strbuf_release(&index_env); strbuf_release(&buf); } static NORETURN void exit_cleanup(const char *tmpdir, int exit_code) { struct strbuf buf = STRBUF_INIT; strbuf_addstr(&buf, tmpdir); remove_dir_recursively(&buf, 0); if (exit_code) warning(_("failed: %d"), exit_code); exit(exit_code); } static int ensure_leading_directories(char *path) { switch (safe_create_leading_directories(path)) { case SCLD_OK: case SCLD_EXISTS: return 0; default: return error(_("could not create leading directories " "of '%s'"), path); } } /* * Unconditional writing of a plain regular file is what * "git difftool --dir-diff" wants to do for symlinks. We are preparing two * temporary directories to be fed to a Git-unaware tool that knows how to * show a diff of two directories (e.g. "diff -r A B"). * * Because the tool is Git-unaware, if a symbolic link appears in either of * these temporary directories, it will try to dereference and show the * difference of the target of the symbolic link, which is not what we want, * as the goal of the dir-diff mode is to produce an output that is logically * equivalent to what "git diff" produces. * * Most importantly, we want to get textual comparison of the result of the * readlink(2). get_symlink() provides that---it returns the contents of * the symlink that gets written to a regular file to force the external tool * to compare the readlink(2) result as text, even on a filesystem that is * capable of doing a symbolic link. */ static char *get_symlink(const struct object_id *oid, const char *path) { char *data; if (is_null_oid(oid)) { /* The symlink is unknown to Git so read from the filesystem */ struct strbuf link = STRBUF_INIT; if (has_symlinks) { if (strbuf_readlink(&link, path, strlen(path))) die(_("could not read symlink %s"), path); } else if (strbuf_read_file(&link, path, 128)) die(_("could not read symlink file %s"), path); data = strbuf_detach(&link, NULL); } else { enum object_type type; unsigned long size; data = read_object_file(oid, &type, &size); if (!data) die(_("could not read object %s for symlink %s"), oid_to_hex(oid), path); } return data; } static int checkout_path(unsigned mode, struct object_id *oid, const char *path, const struct checkout *state) { struct cache_entry *ce; int ret; ce = make_transient_cache_entry(mode, oid, path, 0); ret = checkout_entry(ce, state, NULL); discard_cache_entry(ce); return ret; } static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix, int argc, const char **argv) { char tmpdir[PATH_MAX]; struct strbuf info = STRBUF_INIT, lpath = STRBUF_INIT; struct strbuf rpath = STRBUF_INIT, buf = STRBUF_INIT; struct strbuf ldir = STRBUF_INIT, rdir = STRBUF_INIT; struct strbuf wtdir = STRBUF_INIT; char *lbase_dir, *rbase_dir; size_t ldir_len, rdir_len, wtdir_len; const char *workdir, *tmp; int ret = 0, i; FILE *fp; struct hashmap working_tree_dups, submodules, symlinks2; struct hashmap_iter iter; struct pair_entry *entry; struct index_state wtindex; struct checkout lstate, rstate; int rc, flags = RUN_GIT_CMD, err = 0; struct child_process child = CHILD_PROCESS_INIT; const char *helper_argv[] = { "difftool--helper", NULL, NULL, NULL }; struct hashmap wt_modified, tmp_modified; int indices_loaded = 0; workdir = get_git_work_tree(); /* Setup temp directories */ tmp = getenv("TMPDIR"); xsnprintf(tmpdir, sizeof(tmpdir), "%s/git-difftool.XXXXXX", tmp ? tmp : "/tmp"); if (!mkdtemp(tmpdir)) return error("could not create '%s'", tmpdir); strbuf_addf(&ldir, "%s/left/", tmpdir); strbuf_addf(&rdir, "%s/right/", tmpdir); strbuf_addstr(&wtdir, workdir); if (!wtdir.len || !is_dir_sep(wtdir.buf[wtdir.len - 1])) strbuf_addch(&wtdir, '/'); mkdir(ldir.buf, 0700); mkdir(rdir.buf, 0700); memset(&wtindex, 0, sizeof(wtindex)); memset(&lstate, 0, sizeof(lstate)); lstate.base_dir = lbase_dir = xstrdup(ldir.buf); lstate.base_dir_len = ldir.len; lstate.force = 1; memset(&rstate, 0, sizeof(rstate)); rstate.base_dir = rbase_dir = xstrdup(rdir.buf); rstate.base_dir_len = rdir.len; rstate.force = 1; ldir_len = ldir.len; rdir_len = rdir.len; wtdir_len = wtdir.len; hashmap_init(&working_tree_dups, working_tree_entry_cmp, NULL, 0); hashmap_init(&submodules, pair_cmp, NULL, 0); hashmap_init(&symlinks2, pair_cmp, NULL, 0); child.no_stdin = 1; child.git_cmd = 1; child.use_shell = 0; child.clean_on_exit = 1; child.dir = prefix; child.out = -1; argv_array_pushl(&child.args, "diff", "--raw", "--no-abbrev", "-z", NULL); for (i = 0; i < argc; i++) argv_array_push(&child.args, argv[i]); if (start_command(&child)) die("could not obtain raw diff"); fp = xfdopen(child.out, "r"); /* Build index info for left and right sides of the diff */ i = 0; while (!strbuf_getline_nul(&info, fp)) { int lmode, rmode; struct object_id loid, roid; char status; const char *src_path, *dst_path; if (starts_with(info.buf, "::")) die(N_("combined diff formats('-c' and '--cc') are " "not supported in\n" "directory diff mode('-d' and '--dir-diff').")); if (parse_index_info(info.buf, &lmode, &rmode, &loid, &roid, &status)) break; if (strbuf_getline_nul(&lpath, fp)) break; src_path = lpath.buf; i++; if (status != 'C' && status != 'R') { dst_path = src_path; } else { if (strbuf_getline_nul(&rpath, fp)) break; dst_path = rpath.buf; } if (S_ISGITLINK(lmode) || S_ISGITLINK(rmode)) { strbuf_reset(&buf); strbuf_addf(&buf, "Subproject commit %s", oid_to_hex(&loid)); add_left_or_right(&submodules, src_path, buf.buf, 0); strbuf_reset(&buf); strbuf_addf(&buf, "Subproject commit %s", oid_to_hex(&roid)); if (oideq(&loid, &roid)) strbuf_addstr(&buf, "-dirty"); add_left_or_right(&submodules, dst_path, buf.buf, 1); continue; } if (S_ISLNK(lmode)) { char *content = get_symlink(&loid, src_path); add_left_or_right(&symlinks2, src_path, content, 0); free(content); } if (S_ISLNK(rmode)) { char *content = get_symlink(&roid, dst_path); add_left_or_right(&symlinks2, dst_path, content, 1); free(content); } if (lmode && status != 'C') { if (checkout_path(lmode, &loid, src_path, &lstate)) { ret = error("could not write '%s'", src_path); goto finish; } } if (rmode && !S_ISLNK(rmode)) { struct working_tree_entry *entry; /* Avoid duplicate working_tree entries */ FLEX_ALLOC_STR(entry, path, dst_path); hashmap_entry_init(entry, strhash(dst_path)); if (hashmap_get(&working_tree_dups, entry, NULL)) { free(entry); continue; } hashmap_add(&working_tree_dups, entry); if (!use_wt_file(workdir, dst_path, &roid)) { if (checkout_path(rmode, &roid, dst_path, &rstate)) { ret = error("could not write '%s'", dst_path); goto finish; } } else if (!is_null_oid(&roid)) { /* * Changes in the working tree need special * treatment since they are not part of the * index. */ struct cache_entry *ce2 = make_cache_entry(&wtindex, rmode, &roid, dst_path, 0, 0); add_index_entry(&wtindex, ce2, ADD_CACHE_JUST_APPEND); add_path(&rdir, rdir_len, dst_path); if (ensure_leading_directories(rdir.buf)) { ret = error("could not create " "directory for '%s'", dst_path); goto finish; } add_path(&wtdir, wtdir_len, dst_path); if (symlinks) { if (symlink(wtdir.buf, rdir.buf)) { ret = error_errno("could not symlink '%s' to '%s'", wtdir.buf, rdir.buf); goto finish; } } else { struct stat st; if (stat(wtdir.buf, &st)) st.st_mode = 0644; if (copy_file(rdir.buf, wtdir.buf, st.st_mode)) { ret = error("could not copy '%s' to '%s'", wtdir.buf, rdir.buf); goto finish; } } } } } fclose(fp); fp = NULL; if (finish_command(&child)) { ret = error("error occurred running diff --raw"); goto finish; } if (!i) goto finish; /* * Changes to submodules require special treatment.This loop writes a * temporary file to both the left and right directories to show the * change in the recorded SHA1 for the submodule. */ hashmap_iter_init(&submodules, &iter); while ((entry = hashmap_iter_next(&iter))) { if (*entry->left) { add_path(&ldir, ldir_len, entry->path); ensure_leading_directories(ldir.buf); write_file(ldir.buf, "%s", entry->left); } if (*entry->right) { add_path(&rdir, rdir_len, entry->path); ensure_leading_directories(rdir.buf); write_file(rdir.buf, "%s", entry->right); } } /* * Symbolic links require special treatment.The standard "git diff" * shows only the link itself, not the contents of the link target. * This loop replicates that behavior. */ hashmap_iter_init(&symlinks2, &iter); while ((entry = hashmap_iter_next(&iter))) { if (*entry->left) { add_path(&ldir, ldir_len, entry->path); ensure_leading_directories(ldir.buf); write_file(ldir.buf, "%s", entry->left); } if (*entry->right) { add_path(&rdir, rdir_len, entry->path); ensure_leading_directories(rdir.buf); write_file(rdir.buf, "%s", entry->right); } } strbuf_release(&buf); strbuf_setlen(&ldir, ldir_len); helper_argv[1] = ldir.buf; strbuf_setlen(&rdir, rdir_len); helper_argv[2] = rdir.buf; if (extcmd) { helper_argv[0] = extcmd; flags = 0; } else setenv("GIT_DIFFTOOL_DIRDIFF", "true", 1); rc = run_command_v_opt(helper_argv, flags); /* * If the diff includes working copy files and those * files were modified during the diff, then the changes * should be copied back to the working tree. * Do not copy back files when symlinks are used and the * external tool did not replace the original link with a file. * * These hashes are loaded lazily since they aren't needed * in the common case of --symlinks and the difftool updating * files through the symlink. */ hashmap_init(&wt_modified, path_entry_cmp, NULL, wtindex.cache_nr); hashmap_init(&tmp_modified, path_entry_cmp, NULL, wtindex.cache_nr); for (i = 0; i < wtindex.cache_nr; i++) { struct hashmap_entry dummy; const char *name = wtindex.cache[i]->name; struct stat st; add_path(&rdir, rdir_len, name); if (lstat(rdir.buf, &st)) continue; if ((symlinks && S_ISLNK(st.st_mode)) || !S_ISREG(st.st_mode)) continue; if (!indices_loaded) { struct lock_file lock = LOCK_INIT; strbuf_reset(&buf); strbuf_addf(&buf, "%s/wtindex", tmpdir); if (hold_lock_file_for_update(&lock, buf.buf, 0) < 0 || write_locked_index(&wtindex, &lock, COMMIT_LOCK)) { ret = error("could not write %s", buf.buf); goto finish; } changed_files(&wt_modified, buf.buf, workdir); strbuf_setlen(&rdir, rdir_len); changed_files(&tmp_modified, buf.buf, rdir.buf); add_path(&rdir, rdir_len, name); indices_loaded = 1; } hashmap_entry_init(&dummy, strhash(name)); if (hashmap_get(&tmp_modified, &dummy, name)) { add_path(&wtdir, wtdir_len, name); if (hashmap_get(&wt_modified, &dummy, name)) { warning(_("both files modified: '%s' and '%s'."), wtdir.buf, rdir.buf); warning(_("working tree file has been left.")); warning("%s", ""); err = 1; } else if (unlink(wtdir.buf) || copy_file(wtdir.buf, rdir.buf, st.st_mode)) warning_errno(_("could not copy '%s' to '%s'"), rdir.buf, wtdir.buf); } } if (err) { warning(_("temporary files exist in '%s'."), tmpdir); warning(_("you may want to cleanup or recover these.")); exit(1); } else exit_cleanup(tmpdir, rc); finish: if (fp) fclose(fp); free(lbase_dir); free(rbase_dir); strbuf_release(&ldir); strbuf_release(&rdir); strbuf_release(&wtdir); strbuf_release(&buf); return ret; } static int run_file_diff(int prompt, const char *prefix, int argc, const char **argv) { struct argv_array args = ARGV_ARRAY_INIT; const char *env[] = { "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL, NULL }; int ret = 0, i; if (prompt > 0) env[2] = "GIT_DIFFTOOL_PROMPT=true"; else if (!prompt) env[2] = "GIT_DIFFTOOL_NO_PROMPT=true"; argv_array_push(&args, "diff"); for (i = 0; i < argc; i++) argv_array_push(&args, argv[i]); ret = run_command_v_opt_cd_env(args.argv, RUN_GIT_CMD, prefix, env); exit(ret); } int cmd_difftool(int argc, const char **argv, const char *prefix) { int use_gui_tool = 0, dir_diff = 0, prompt = -1, symlinks = 0, tool_help = 0; static char *difftool_cmd = NULL, *extcmd = NULL; struct option builtin_difftool_options[] = { OPT_BOOL('g', "gui", &use_gui_tool, N_("use `diff.guitool` instead of `diff.tool`")), OPT_BOOL('d', "dir-diff", &dir_diff, N_("perform a full-directory diff")), OPT_SET_INT_F('y', "no-prompt", &prompt, N_("do not prompt before launching a diff tool"), 0, PARSE_OPT_NONEG), OPT_SET_INT_F(0, "prompt", &prompt, NULL, 1, PARSE_OPT_NONEG | PARSE_OPT_HIDDEN), OPT_BOOL(0, "symlinks", &symlinks, N_("use symlinks in dir-diff mode")), OPT_STRING('t', "tool", &difftool_cmd, N_("tool"), N_("use the specified diff tool")), OPT_BOOL(0, "tool-help", &tool_help, N_("print a list of diff tools that may be used with " "`--tool`")), OPT_BOOL(0, "trust-exit-code", &trust_exit_code, N_("make 'git-difftool' exit when an invoked diff " "tool returns a non - zero exit code")), OPT_STRING('x', "extcmd", &extcmd, N_("command"), N_("specify a custom command for viewing diffs")), OPT_END() }; git_config(difftool_config, NULL); symlinks = has_symlinks; argc = parse_options(argc, argv, prefix, builtin_difftool_options, builtin_difftool_usage, PARSE_OPT_KEEP_UNKNOWN | PARSE_OPT_KEEP_DASHDASH); if (tool_help) return print_tool_help(); /* NEEDSWORK: once we no longer spawn anything, remove this */ setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1); setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1); if (use_gui_tool && diff_gui_tool && *diff_gui_tool) setenv("GIT_DIFF_TOOL", diff_gui_tool, 1); else if (difftool_cmd) { if (*difftool_cmd) setenv("GIT_DIFF_TOOL", difftool_cmd, 1); else die(_("no <tool> given for --tool=<tool>")); } if (extcmd) { if (*extcmd) setenv("GIT_DIFFTOOL_EXTCMD", extcmd, 1); else die(_("no <cmd> given for --extcmd=<cmd>")); } setenv("GIT_DIFFTOOL_TRUST_EXIT_CODE", trust_exit_code ? "true" : "false", 1); /* * In directory diff mode, 'git-difftool--helper' is called once * to compare the a / b directories. In file diff mode, 'git diff' * will invoke a separate instance of 'git-difftool--helper' for * each file that changed. */ if (dir_diff) return run_dir_diff(extcmd, symlinks, prefix, argc, argv); return run_file_diff(prompt, prefix, argc, argv); }