Git 2.23
[gitweb.git] / builtin / difftool.c
index d13350ce832cd8c0064c8a5b2d3c9be64f876b8d..16eb8b70ea33eb00516d7ab035a90df9728d5296 100644 (file)
  *
  * Copyright (C) 2016 Johannes Schindelin
  */
+#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "config.h"
 #include "builtin.h"
 #include "run-command.h"
-#include "exec_cmd.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[] = {
@@ -31,11 +33,6 @@ static const char *const builtin_difftool_usage[] = {
 
 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;
@@ -62,14 +59,12 @@ static int parse_index_info(char *p, int *mode1, int *mode2,
        *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 (parse_oid_hex(++p, oid1, (const char **)&p))
+               return error("expected object ID, got '%s'", p);
        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 (parse_oid_hex(++p, oid2, (const char **)&p))
+               return error("expected object ID, got '%s'", p);
        if (*p != ' ')
                return error("expected ' ', got '%c'", *p);
        *status = *++p;
@@ -110,11 +105,11 @@ static int use_wt_file(const char *workdir, const char *name,
                int fd = open(buf.buf, O_RDONLY);
 
                if (fd >= 0 &&
-                   !index_fd(wt_oid.hash, fd, &st, OBJ_BLOB, name, 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 (!oidcmp(oid, &wt_oid))
+                       } else if (oideq(oid, &wt_oid))
                                use = 1;
                }
        }
@@ -129,9 +124,13 @@ struct working_tree_entry {
        char path[FLEX_ARRAY];
 };
 
-static int working_tree_entry_cmp(struct working_tree_entry *a,
-                                 struct working_tree_entry *b, void *keydata)
+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);
 }
 
@@ -145,8 +144,14 @@ struct pair_entry {
        const char path[FLEX_ARRAY];
 };
 
-static int pair_cmp(struct pair_entry *a, struct pair_entry *b, void *keydata)
+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);
 }
 
@@ -173,8 +178,14 @@ struct path_entry {
        char path[FLEX_ARRAY];
 };
 
-static int path_entry_cmp(struct path_entry *a, struct path_entry *b, void *key)
+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);
 }
 
@@ -226,6 +237,7 @@ static void changed_files(struct hashmap *result, const char *index_path,
                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);
@@ -254,6 +266,62 @@ static int ensure_leading_directories(char *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, 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)
 {
@@ -262,16 +330,14 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        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;
-       struct cache_entry *ce = xcalloc(1, sizeof(ce) + PATH_MAX + 1);
        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;
-       enum object_type type;
-       unsigned long size;
        struct index_state wtindex;
        struct checkout lstate, rstate;
        int rc, flags = RUN_GIT_CMD, err = 0;
@@ -298,11 +364,11 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        memset(&wtindex, 0, sizeof(wtindex));
 
        memset(&lstate, 0, sizeof(lstate));
-       lstate.base_dir = ldir.buf;
+       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 = rdir.buf;
+       rstate.base_dir = rbase_dir = xstrdup(rdir.buf);
        rstate.base_dir_len = rdir.len;
        rstate.force = 1;
 
@@ -310,10 +376,9 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        rdir_len = rdir.len;
        wtdir_len = wtdir.len;
 
-       hashmap_init(&working_tree_dups,
-                    (hashmap_cmp_fn)working_tree_entry_cmp, 0);
-       hashmap_init(&submodules, (hashmap_cmp_fn)pair_cmp, 0);
-       hashmap_init(&symlinks2, (hashmap_cmp_fn)pair_cmp, 0);
+       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;
@@ -336,7 +401,6 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                struct object_id loid, roid;
                char status;
                const char *src_path, *dst_path;
-               size_t src_path_len, dst_path_len;
 
                if (starts_with(info.buf, "::"))
                        die(N_("combined diff formats('-c' and '--cc') are "
@@ -349,17 +413,14 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                if (strbuf_getline_nul(&lpath, fp))
                        break;
                src_path = lpath.buf;
-               src_path_len = lpath.len;
 
                i++;
                if (status != 'C' && status != 'R') {
                        dst_path = src_path;
-                       dst_path_len = src_path_len;
                } else {
                        if (strbuf_getline_nul(&rpath, fp))
                                break;
                        dst_path = rpath.buf;
-                       dst_path_len = rpath.len;
                }
 
                if (S_ISGITLINK(lmode) || S_ISGITLINK(rmode)) {
@@ -370,34 +431,32 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                        strbuf_reset(&buf);
                        strbuf_addf(&buf, "Subproject commit %s",
                                    oid_to_hex(&roid));
-                       if (!oidcmp(&loid, &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 = read_sha1_file(loid.hash, &type, &size);
+                       char *content = get_symlink(&loid, src_path);
                        add_left_or_right(&symlinks2, src_path, content, 0);
                        free(content);
                }
 
                if (S_ISLNK(rmode)) {
-                       char *content = read_sha1_file(roid.hash, &type, &size);
+                       char *content = get_symlink(&roid, dst_path);
                        add_left_or_right(&symlinks2, dst_path, content, 1);
                        free(content);
                }
 
                if (lmode && status != 'C') {
-                       ce->ce_mode = lmode;
-                       oidcpy(&ce->oid, &loid);
-                       strcpy(ce->name, src_path);
-                       ce->ce_namelen = src_path_len;
-                       if (checkout_entry(ce, &lstate, NULL))
-                               return error("could not write '%s'", src_path);
+                       if (checkout_path(lmode, &loid, src_path, &lstate)) {
+                               ret = error("could not write '%s'", src_path);
+                               goto finish;
+                       }
                }
 
-               if (rmode) {
+               if (rmode && !S_ISLNK(rmode)) {
                        struct working_tree_entry *entry;
 
                        /* Avoid duplicate working_tree entries */
@@ -410,13 +469,12 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                        hashmap_add(&working_tree_dups, entry);
 
                        if (!use_wt_file(workdir, dst_path, &roid)) {
-                               ce->ce_mode = rmode;
-                               oidcpy(&ce->oid, &roid);
-                               strcpy(ce->name, dst_path);
-                               ce->ce_namelen = dst_path_len;
-                               if (checkout_entry(ce, &rstate, NULL))
-                                       return error("could not write '%s'",
-                                                    dst_path);
+                               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
@@ -424,17 +482,19 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                                 * index.
                                 */
                                struct cache_entry *ce2 =
-                                       make_cache_entry(rmode, roid.hash,
+                                       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))
-                                       return error("could not create "
-                                                    "directory for '%s'",
-                                                    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)) {
@@ -455,13 +515,15 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                }
        }
 
+       fclose(fp);
+       fp = NULL;
        if (finish_command(&child)) {
                ret = error("error occurred running diff --raw");
                goto finish;
        }
 
        if (!i)
-               return 0;
+               goto finish;
 
        /*
         * Changes to submodules require special treatment.This loop writes a
@@ -526,10 +588,8 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
         * in the common case of --symlinks and the difftool updating
         * files through the symlink.
         */
-       hashmap_init(&wt_modified, (hashmap_cmp_fn)path_entry_cmp,
-                    wtindex.cache_nr);
-       hashmap_init(&tmp_modified, (hashmap_cmp_fn)path_entry_cmp,
-                    wtindex.cache_nr);
+       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;
@@ -544,13 +604,12 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                        continue;
 
                if (!indices_loaded) {
-                       static struct lock_file lock;
+                       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);
-                               rollback_lock_file(&lock);
                                goto finish;
                        }
                        changed_files(&wt_modified, buf.buf, workdir);
@@ -584,7 +643,11 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                exit_cleanup(tmpdir, rc);
 
 finish:
-       free(ce);
+       if (fp)
+               fclose(fp);
+
+       free(lbase_dir);
+       free(rbase_dir);
        strbuf_release(&ldir);
        strbuf_release(&rdir);
        strbuf_release(&wtdir);
@@ -619,22 +682,21 @@ static int run_file_diff(int prompt, const char *prefix,
 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;
+           tool_help = 0, no_index = 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")),
-               { OPTION_SET_INT, 'y', "no-prompt", &prompt, NULL,
+               OPT_SET_INT_F('y', "no-prompt", &prompt,
                        N_("do not prompt before launching a diff tool"),
-                       PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 0},
-               { OPTION_SET_INT, 0, "prompt", &prompt, NULL, NULL,
-                       PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_HIDDEN,
-                       NULL, 1 },
+                       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>"),
+               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 "
@@ -642,8 +704,9 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
                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>"),
+               OPT_STRING('x', "extcmd", &extcmd, N_("command"),
                           N_("specify a custom command for viewing diffs")),
+               OPT_ARGUMENT("no-index", &no_index, N_("passed to `diff`")),
                OPT_END()
        };
 
@@ -657,12 +720,21 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
        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 (!no_index && !startup_info->have_repository)
+               die(_("difftool requires worktree or --no-index"));
+
+       if (!no_index){
+               setup_work_tree();
+               setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1);
+               setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
+       } else if (dir_diff)
+               die(_("--dir-diff is incompatible with --no-index"));
+
+       if (use_gui_tool + !!difftool_cmd + !!extcmd > 1)
+               die(_("--gui, --tool and --extcmd are mutually exclusive"));
 
-       if (use_gui_tool && diff_gui_tool && *diff_gui_tool)
-               setenv("GIT_DIFF_TOOL", diff_gui_tool, 1);
+       if (use_gui_tool)
+               setenv("GIT_MERGETOOL_GUI", "true", 1);
        else if (difftool_cmd) {
                if (*difftool_cmd)
                        setenv("GIT_DIFF_TOOL", difftool_cmd, 1);