+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <limits.h>
#include "cache.h"
#include "diff.h"
-static char *diff_cmd = "diff -L 'k/%s' -L 'l/%s' ";
-static char *diff_opts = "-p -u";
-static char *diff_arg_forward = " - '%s'";
-static char *diff_arg_reverse = " '%s' -";
+static const char *diff_opts = "-pu";
-void prepare_diff_cmd(void)
+static const char *external_diff(void)
{
+ static const char *external_diff_cmd = NULL;
+ static int done_preparing = 0;
+
+ if (done_preparing)
+ return external_diff_cmd;
+
/*
* Default values above are meant to match the
* Linux kernel development style. Examples of
* alternative styles you can specify via environment
* variables are:
*
- * GIT_DIFF_CMD="diff -L '%s' -L '%s'"
* GIT_DIFF_OPTS="-c";
*/
- diff_cmd = getenv("GIT_DIFF_CMD") ? : diff_cmd;
- diff_opts = getenv("GIT_DIFF_OPTS") ? : diff_opts;
+ if (gitenv("GIT_EXTERNAL_DIFF"))
+ external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
+
+ /* In case external diff fails... */
+ diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
+
+ done_preparing = 1;
+ return external_diff_cmd;
}
/* Help to copy the thing properly quoted for the shell safety.
if (*cp == '\'')
cnt += 3;
- if (! (buf = malloc(cnt)))
- return buf;
+ buf = xmalloc(cnt);
bp = buf;
while ((c = *src++)) {
if (c != '\'')
return buf;
}
-void show_differences(const char *name, /* filename on the filesystem */
- const char *label, /* diff label to use */
- void *old_contents, /* contents in core */
- unsigned long long old_size, /* size in core */
- int reverse /* 0: diff core file
- 1: diff file core */)
+static struct diff_tempfile {
+ const char *name;
+ char hex[41];
+ char mode[10];
+ char tmp_path[50];
+} diff_temp[2];
+
+static void builtin_diff(const char *name,
+ struct diff_tempfile *temp)
+{
+ int i, next_at;
+ const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
+ const char *diff_arg = "'%s' '%s'||:"; /* "||:" is to return 0 */
+ const char *input_name_sq[2];
+ const char *path0[2];
+ const char *path1[2];
+ const char *name_sq = sq_expand(name);
+ char *cmd;
+
+ /* diff_cmd and diff_arg have 6 %s in total which makes
+ * the sum of these strings 12 bytes larger than required.
+ * we use 2 spaces around diff-opts, and we need to count
+ * terminating NUL, so we subtract 9 here.
+ */
+ int cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
+ strlen(diff_arg) - 9);
+ for (i = 0; i < 2; i++) {
+ input_name_sq[i] = sq_expand(temp[i].name);
+ if (!strcmp(temp[i].name, "/dev/null")) {
+ path0[i] = "/dev/null";
+ path1[i] = "";
+ } else {
+ path0[i] = i ? "b/" : "a/";
+ path1[i] = name_sq;
+ }
+ cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
+ strlen(input_name_sq[i]));
+ }
+
+ cmd = xmalloc(cmd_size);
+
+ next_at = 0;
+ next_at += snprintf(cmd+next_at, cmd_size-next_at,
+ diff_cmd,
+ path0[0], path1[0], path0[1], path1[1]);
+ next_at += snprintf(cmd+next_at, cmd_size-next_at,
+ " %s ", diff_opts);
+ next_at += snprintf(cmd+next_at, cmd_size-next_at,
+ diff_arg, input_name_sq[0], input_name_sq[1]);
+
+ if (!path1[0][0])
+ printf("Created: %s (mode:%s)\n", name, temp[1].mode);
+ else if (!path1[1][0])
+ printf("Deleted: %s\n", name);
+ else if (strcmp(temp[0].mode, temp[1].mode)) {
+ printf("Mode changed: %s (%s->%s)\n", name,
+ temp[0].mode, temp[1].mode);
+ /* Be careful. We do not want to diff between
+ * symlink and a file.
+ */
+ if (strncmp(temp[0].mode, "120", 3) !=
+ strncmp(temp[1].mode, "120", 3))
+ exit(0);
+ }
+ fflush(NULL);
+ execlp("/bin/sh","sh", "-c", cmd, NULL);
+}
+
+/*
+ * Given a name and sha1 pair, if the dircache tells us the file in
+ * the work tree has that object contents, return true, so that
+ * prepare_temp_file() does not have to inflate and extract.
+ */
+static int work_tree_matches(const char *name, const unsigned char *sha1)
{
- FILE *f;
- char *name_sq = sq_expand(name);
- const char *label_sq = (name != label) ? sq_expand(label) : name_sq;
- char *diff_arg = reverse ? diff_arg_reverse : diff_arg_forward;
- int cmd_size = strlen(name_sq) + strlen(label_sq) * 2 +
- strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg);
- char *cmd = malloc(cmd_size);
- int next_at;
-
- fflush(stdout);
- next_at = snprintf(cmd, cmd_size, diff_cmd, label_sq, label_sq);
- next_at += snprintf(cmd+next_at, cmd_size-next_at, "%s", diff_opts);
- next_at += snprintf(cmd+next_at, cmd_size-next_at, diff_arg, name_sq);
- f = popen(cmd, "w");
- if (old_size)
- fwrite(old_contents, old_size, 1, f);
- pclose(f);
- if (label_sq != name_sq)
- free((void*)label_sq); /* constness */
- free(name_sq);
- free(cmd);
+ struct cache_entry *ce;
+ struct stat st;
+ int pos, len;
+
+ /* We do not read the cache ourselves here, because the
+ * benchmark with my previous version that always reads cache
+ * shows that it makes things worse for diff-tree comparing
+ * two linux-2.6 kernel trees in an already checked out work
+ * tree. This is because most diff-tree comparison deals with
+ * only a small number of files, while reading the cache is
+ * expensive for a large project, and its cost outweighs the
+ * savings we get by not inflating the object to a temporary
+ * file. Practically, this code only helps when we are used
+ * by diff-cache --cached, which does read the cache before
+ * calling us.
+ */
+ if (!active_cache)
+ return 0;
+
+ len = strlen(name);
+ pos = cache_name_pos(name, len);
+ if (pos < 0)
+ return 0;
+ ce = active_cache[pos];
+ if ((lstat(name, &st) < 0) ||
+ !S_ISREG(st.st_mode) ||
+ cache_match_stat(ce, &st) ||
+ memcmp(sha1, ce->sha1, 20))
+ return 0;
+ return 1;
}
-void show_diff_empty(const unsigned char *sha1,
- const char *name,
- int reverse)
+static void prep_temp_blob(struct diff_tempfile *temp,
+ void *blob,
+ unsigned long size,
+ unsigned char *sha1,
+ int mode)
{
- char *old;
- unsigned long int size;
- unsigned char type[20];
-
- old = read_sha1_file(sha1, type, &size);
- if (! old) {
- error("unable to read blob object for %s (%s)", name,
- sha1_to_hex(sha1));
+ int fd;
+
+ strcpy(temp->tmp_path, ".diff_XXXXXX");
+ fd = mkstemp(temp->tmp_path);
+ if (fd < 0)
+ die("unable to create temp-file");
+ if (write(fd, blob, size) != size)
+ die("unable to write temp-file");
+ close(fd);
+ temp->name = temp->tmp_path;
+ strcpy(temp->hex, sha1_to_hex(sha1));
+ temp->hex[40] = 0;
+ sprintf(temp->mode, "%06o", mode);
+}
+
+static void prepare_temp_file(const char *name,
+ struct diff_tempfile *temp,
+ struct diff_spec *one)
+{
+ static unsigned char null_sha1[20] = { 0, };
+ int use_work_tree = 0;
+
+ if (!one->file_valid) {
+ not_a_valid_file:
+ /* A '-' entry produces this for file-2, and
+ * a '+' entry produces this for file-1.
+ */
+ temp->name = "/dev/null";
+ strcpy(temp->hex, ".");
+ strcpy(temp->mode, ".");
return;
}
- show_differences("/dev/null", name, old, size, reverse);
+
+ if (one->sha1_valid &&
+ (!memcmp(one->blob_sha1, null_sha1, sizeof(null_sha1)) ||
+ work_tree_matches(name, one->blob_sha1)))
+ use_work_tree = 1;
+
+ if (!one->sha1_valid || use_work_tree) {
+ struct stat st;
+ temp->name = name;
+ if (lstat(temp->name, &st) < 0) {
+ if (errno == ENOENT)
+ goto not_a_valid_file;
+ die("stat(%s): %s", temp->name, strerror(errno));
+ }
+ if (S_ISLNK(st.st_mode)) {
+ int ret;
+ char *buf, buf_[1024];
+ buf = ((sizeof(buf_) < st.st_size) ?
+ xmalloc(st.st_size) : buf_);
+ ret = readlink(name, buf, st.st_size);
+ if (ret < 0)
+ die("readlink(%s)", name);
+ prep_temp_blob(temp, buf, st.st_size,
+ (one->sha1_valid ?
+ one->blob_sha1 : null_sha1),
+ (one->sha1_valid ?
+ one->mode : S_IFLNK));
+ }
+ else {
+ if (!one->sha1_valid)
+ strcpy(temp->hex, sha1_to_hex(null_sha1));
+ else
+ strcpy(temp->hex, sha1_to_hex(one->blob_sha1));
+ sprintf(temp->mode, "%06o",
+ S_IFREG |ce_permissions(st.st_mode));
+ }
+ return;
+ }
+ else {
+ void *blob;
+ char type[20];
+ unsigned long size;
+
+ blob = read_sha1_file(one->blob_sha1, type, &size);
+ if (!blob || strcmp(type, "blob"))
+ die("unable to read blob object for %s (%s)",
+ name, sha1_to_hex(one->blob_sha1));
+ prep_temp_blob(temp, blob, size, one->blob_sha1, one->mode);
+ free(blob);
+ }
+}
+
+static void remove_tempfile(void)
+{
+ int i;
+
+ for (i = 0; i < 2; i++)
+ if (diff_temp[i].name == diff_temp[i].tmp_path) {
+ unlink(diff_temp[i].name);
+ diff_temp[i].name = NULL;
+ }
+}
+
+static void remove_tempfile_on_signal(int signo)
+{
+ remove_tempfile();
+}
+
+/* An external diff command takes:
+ *
+ * diff-cmd name infile1 infile1-sha1 infile1-mode \
+ * infile2 infile2-sha1 infile2-mode.
+ *
+ */
+void run_external_diff(const char *name,
+ struct diff_spec *one,
+ struct diff_spec *two)
+{
+ struct diff_tempfile *temp = diff_temp;
+ pid_t pid;
+ int status;
+ static int atexit_asked = 0;
+
+ if (one && two) {
+ prepare_temp_file(name, &temp[0], one);
+ prepare_temp_file(name, &temp[1], two);
+ if (! atexit_asked &&
+ (temp[0].name == temp[0].tmp_path ||
+ temp[1].name == temp[1].tmp_path)) {
+ atexit_asked = 1;
+ atexit(remove_tempfile);
+ }
+ signal(SIGINT, remove_tempfile_on_signal);
+ }
+
+ fflush(NULL);
+ pid = fork();
+ if (pid < 0)
+ die("unable to fork");
+ if (!pid) {
+ const char *pgm = external_diff();
+ if (pgm) {
+ if (one && two)
+ execlp(pgm, pgm,
+ name,
+ temp[0].name, temp[0].hex, temp[0].mode,
+ temp[1].name, temp[1].hex, temp[1].mode,
+ NULL);
+ else
+ execlp(pgm, pgm, name, NULL);
+ }
+ /*
+ * otherwise we use the built-in one.
+ */
+ if (one && two)
+ builtin_diff(name, temp);
+ else
+ printf("* Unmerged path %s\n", name);
+ exit(0);
+ }
+ if (waitpid(pid, &status, 0) < 0 ||
+ !WIFEXITED(status) || WEXITSTATUS(status)) {
+ /* Earlier we did not check the exit status because
+ * diff exits non-zero if files are different, and
+ * we are not interested in knowing that. It was a
+ * mistake which made it harder to quit a diff-*
+ * session that uses the git-apply-patch-script as
+ * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
+ * should also exit non-zero only when it wants to
+ * abort the entire diff-* session.
+ */
+ remove_tempfile();
+ fprintf(stderr, "external diff died, stopping at %s.\n", name);
+ exit(1);
+ }
+ remove_tempfile();
+}
+
+void diff_addremove(int addremove, unsigned mode,
+ const unsigned char *sha1,
+ const char *base, const char *path)
+{
+ char concatpath[PATH_MAX];
+ struct diff_spec spec[2], *one, *two;
+
+ memcpy(spec[0].blob_sha1, sha1, 20);
+ spec[0].mode = mode;
+ spec[0].sha1_valid = spec[0].file_valid = 1;
+ spec[1].file_valid = 0;
+
+ if (addremove == '+') {
+ one = spec + 1; two = spec;
+ } else {
+ one = spec; two = one + 1;
+ }
+
+ if (path) {
+ strcpy(concatpath, base);
+ strcat(concatpath, path);
+ }
+ run_external_diff(path ? concatpath : base, one, two);
+}
+
+void diff_change(unsigned old_mode, unsigned new_mode,
+ const unsigned char *old_sha1,
+ const unsigned char *new_sha1,
+ const char *base, const char *path) {
+ char concatpath[PATH_MAX];
+ struct diff_spec spec[2];
+
+ memcpy(spec[0].blob_sha1, old_sha1, 20);
+ spec[0].mode = old_mode;
+ memcpy(spec[1].blob_sha1, new_sha1, 20);
+ spec[1].mode = new_mode;
+ spec[0].sha1_valid = spec[0].file_valid = 1;
+ spec[1].sha1_valid = spec[1].file_valid = 1;
+
+ if (path) {
+ strcpy(concatpath, base);
+ strcat(concatpath, path);
+ }
+ run_external_diff(path ? concatpath : base, &spec[0], &spec[1]);
+}
+
+void diff_unmerge(const char *path)
+{
+ run_external_diff(path, NULL, NULL);
}
projects / git.git / blobdiff