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authorJunio C Hamano <junkio@cox.net>2005-04-26 16:25:05 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-26 16:25:05 (GMT)
commitbe3cfa85f45e32722a65349d023667be906a66b6 (patch)
treea172f60b1266b028962753354a367142f34c090d /diff.c
parentd1df5743809614241883ecad51876607cf432034 (diff)
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[PATCH] Diff-tree-helper take two.
This reworks the diff-tree-helper and show-diff to further make external diff command interface simpler. These commands now honor GIT_EXTERNAL_DIFF environment variable which can point at an arbitrary program that takes 7 parameters: name file1 file1-sha1 file1-mode file2 file2-sha1 file2-mode The parameters for an external diff command are as follows: name this invocation of the command is to emit diff for the named cache/tree entry. file1 pathname that holds the contents of the first file. This can be a file inside the working tree, or a temporary file created from the blob object, or /dev/null. The command should not attempt to unlink it -- the temporary is unlinked by the caller. file1-sha1 sha1 hash if file1 is a blob object, or "." otherwise. file1-mode mode bits for file1, or "." for a deleted file. If GIT_EXTERNAL_DIFF environment variable is not set, the default is to invoke diff with the set of parameters old show-diff used to use. This built-in implementation honors the GIT_DIFF_CMD and GIT_DIFF_OPTS environment variables as before. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'diff.c')
-rw-r--r--diff.c248
1 files changed, 205 insertions, 43 deletions
diff --git a/diff.c b/diff.c
index dcefe98..9905cdb 100644
--- a/diff.c
+++ b/diff.c
@@ -1,13 +1,22 @@
+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include <sys/types.h>
+#include <sys/wait.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 char *diff_cmd = "diff -L'k/%s' -L'l/%s'";
+static char *diff_opts = "-pu";
-void prepare_diff_cmd(void)
+static const char *external_diff(void)
{
+ static 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
@@ -17,8 +26,15 @@ void prepare_diff_cmd(void)
* GIT_DIFF_CMD="diff -L '%s' -L '%s'"
* GIT_DIFF_OPTS="-c";
*/
+ if (getenv("GIT_EXTERNAL_DIFF"))
+ external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
+
+ /* In case external diff fails... */
diff_cmd = getenv("GIT_DIFF_CMD") ? : diff_cmd;
diff_opts = getenv("GIT_DIFF_OPTS") ? : diff_opts;
+
+ done_preparing = 1;
+ return external_diff_cmd;
}
/* Help to copy the thing properly quoted for the shell safety.
@@ -58,49 +74,195 @@ static char *sq_expand(const char *src)
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)
{
- 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);
+ static char *diff_arg = "'%s' '%s'";
+ const char *name_1_sq = sq_expand(temp[0].name);
+ const char *name_2_sq = sq_expand(temp[1].name);
+ const char *name_sq = sq_expand(name);
+
+ /* diff_cmd and diff_arg have 4 %s in total which makes
+ * the sum of these strings 8 bytes larger than required.
+ * we use 2 spaces around diff-opts, and we need to count
+ * terminating NUL, so we subtract 5 here.
+ */
+ int cmd_size = (strlen(diff_cmd) +
+ strlen(name_sq) * 2 +
+ strlen(diff_opts) +
+ strlen(diff_arg) +
+ strlen(name_1_sq) + strlen(name_2_sq)
+ - 5);
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);
+ int next_at = 0;
+
+ next_at += snprintf(cmd+next_at, cmd_size-next_at,
+ diff_cmd, name_sq, name_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_1_sq, name_2_sq);
+ execlp("/bin/sh","sh", "-c", cmd, NULL);
}
-void show_diff_empty(const unsigned char *sha1,
- const char *name,
- int reverse)
+static void prepare_temp_file(const char *name,
+ struct diff_tempfile *temp,
+ struct diff_spec *one)
{
- 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));
+ static unsigned char null_sha1[20] = { 0, };
+
+ if (!one->file_valid) {
+ not_a_valid_file:
+ 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->u.sha1, null_sha1, sizeof(null_sha1))) {
+ one->sha1_valid = 0;
+ one->u.name = name;
+ }
+
+ if (!one->sha1_valid) {
+ struct stat st;
+ temp->name = one->u.name;
+ if (stat(temp->name, &st) < 0) {
+ if (errno == ENOENT)
+ goto not_a_valid_file;
+ die("stat(%s): %s", temp->name, strerror(errno));
+ }
+ strcpy(temp->hex, ".");
+ sprintf(temp->mode, "%06o",
+ S_IFREG |ce_permissions(st.st_mode));
+ }
+ else {
+ int fd;
+ void *blob;
+ char type[20];
+ unsigned long size;
+
+ blob = read_sha1_file(one->u.sha1, type, &size);
+ if (!blob || strcmp(type, "blob"))
+ die("unable to read blob object for %s (%s)",
+ name, sha1_to_hex(one->u.sha1));
+
+ 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);
+ free(blob);
+ temp->name = temp->tmp_path;
+ strcpy(temp->hex, sha1_to_hex(one->u.sha1));
+ temp->hex[40] = 0;
+ sprintf(temp->mode, "%06o", one->mode);
+ }
+}
+
+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;
+ }
+}
+
+/* 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;
+ int pid, status;
+ static int atexit_asked = 0;
+
+ 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);
+ }
+
+ fflush(NULL);
+ pid = fork();
+ if (pid < 0)
+ die("unable to fork");
+ if (!pid) {
+ const char *pgm = external_diff();
+ if (pgm)
+ execlp(pgm, pgm,
+ name,
+ temp[0].name, temp[0].hex, temp[0].mode,
+ temp[1].name, temp[1].hex, temp[1].mode,
+ NULL);
+ /*
+ * otherwise we use the built-in one.
+ */
+ builtin_diff(name, temp);
+ exit(0);
+ }
+ if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status))
+ die("diff program failed");
+
+ remove_tempfile();
+}
+
+void show_diff_empty(const struct cache_entry *ce, int reverse)
+{
+ struct diff_spec spec[2], *one, *two;
+
+ memcpy(spec[0].u.sha1, ce->sha1, 20);
+ spec[0].mode = ntohl(ce->ce_mode);
+ spec[0].sha1_valid = spec[0].file_valid = 1;
+ spec[1].file_valid = 0;
+
+ if (reverse) {
+ one = spec + 1; two = spec;
+ } else {
+ one = spec; two = one + 1;
+ }
+
+ run_external_diff(ce->name, one, two);
+}
+
+void show_differences(const struct cache_entry *ce, int reverse)
+{
+ struct diff_spec spec[2], *one, *two;
+
+ memcpy(spec[0].u.sha1, ce->sha1, 20);
+ spec[0].mode = ntohl(ce->ce_mode);
+ spec[0].sha1_valid = spec[0].file_valid = 1;
+
+ spec[1].u.name = ce->name; /* the name we stated */
+ spec[1].sha1_valid = 0;
+ spec[1].file_valid = 1;
+
+ if (reverse) {
+ one = spec + 1; two = spec;
+ } else {
+ one = spec; two = one + 1;
+ }
+
+ run_external_diff(ce->name, one, two);
}