+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
#include "cache.h"
#include "diff.h"
+#include "diffcore.h"
+
+static const char *diff_opts = "-pu";
+static unsigned char null_sha1[20] = { 0, };
-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 int reverse_diff;
+static int use_size_cache;
-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.
const char *cp;
char *bp;
- /* count bytes needed to store the quoted string. */
+ /* count bytes needed to store the quoted string. */
for (cnt = 1, cp = src; *cp; cnt++, cp++)
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 */)
-{
- 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);
-}
-
-void show_diff_empty(const unsigned char *sha1,
- const char *name,
- int reverse)
-{
- 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 struct diff_tempfile {
+ const char *name; /* filename external diff should read from */
+ char hex[41];
+ char mode[10];
+ char tmp_path[50];
+} diff_temp[2];
+
+static void builtin_diff(const char *name_a,
+ const char *name_b,
+ struct diff_tempfile *temp,
+ const char *xfrm_msg)
+{
+ int i, next_at, cmd_size;
+ 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[2];
+ char *cmd;
+
+ name_sq[0] = sq_expand(name_a);
+ name_sq[1] = sq_expand(name_b);
+
+ /* 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.
+ */
+ 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[i];
+ }
+ 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]);
+
+ printf("diff --git a/%s b/%s\n", name_a, name_b);
+ if (!path1[0][0]) {
+ printf("new file mode %s\n", temp[1].mode);
+ if (xfrm_msg && xfrm_msg[0])
+ puts(xfrm_msg);
+ }
+ else if (!path1[1][0]) {
+ printf("deleted file mode %s\n", temp[0].mode);
+ if (xfrm_msg && xfrm_msg[0])
+ puts(xfrm_msg);
+ }
+ else {
+ if (strcmp(temp[0].mode, temp[1].mode)) {
+ printf("old mode %s\n", temp[0].mode);
+ printf("new mode %s\n", temp[1].mode);
+ }
+ if (xfrm_msg && xfrm_msg[0])
+ puts(xfrm_msg);
+
+ if (strncmp(temp[0].mode, temp[1].mode, 3))
+ /* we do not run diff between different kind
+ * of objects.
+ */
+ exit(0);
+ }
+ fflush(NULL);
+ execlp("/bin/sh","sh", "-c", cmd, NULL);
+}
+
+struct diff_filespec *alloc_filespec(const char *path)
+{
+ int namelen = strlen(path);
+ struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+ spec->path = (char *)(spec + 1);
+ strcpy(spec->path, path);
+ spec->should_free = spec->should_munmap = 0;
+ spec->xfrm_flags = 0;
+ spec->size = 0;
+ spec->data = NULL;
+ spec->mode = 0;
+ memset(spec->sha1, 0, 20);
+ return spec;
+}
+
+void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
+ unsigned short mode)
+{
+ if (mode) {
+ spec->mode = DIFF_FILE_CANON_MODE(mode);
+ memcpy(spec->sha1, sha1, 20);
+ spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
+ }
+}
+
+/*
+ * 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)
+{
+ 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 comparisons deal 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) || /* careful! */
+ ce_match_stat(ce, &st) ||
+ memcmp(sha1, ce->sha1, 20))
+ return 0;
+ /* we return 1 only when we can stat, it is a regular file,
+ * stat information matches, and sha1 recorded in the cache
+ * matches. I.e. we know the file in the work tree really is
+ * the same as the <name, sha1> pair.
+ */
+ return 1;
+}
+
+static struct sha1_size_cache {
+ unsigned char sha1[20];
+ unsigned long size;
+} **sha1_size_cache;
+static int sha1_size_cache_nr, sha1_size_cache_alloc;
+
+static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
+ int find_only,
+ unsigned long size)
+{
+ int first, last;
+ struct sha1_size_cache *e;
+
+ first = 0;
+ last = sha1_size_cache_nr;
+ while (last > first) {
+ int cmp, next = (last + first) >> 1;
+ e = sha1_size_cache[next];
+ cmp = memcmp(e->sha1, sha1, 20);
+ if (!cmp)
+ return e;
+ if (cmp < 0) {
+ last = next;
+ continue;
+ }
+ first = next+1;
+ }
+ /* not found */
+ if (find_only)
+ return NULL;
+ /* insert to make it at "first" */
+ if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
+ sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
+ sha1_size_cache = xrealloc(sha1_size_cache,
+ sha1_size_cache_alloc *
+ sizeof(*sha1_size_cache));
+ }
+ sha1_size_cache_nr++;
+ if (first < sha1_size_cache_nr)
+ memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
+ (sha1_size_cache_nr - first - 1) *
+ sizeof(*sha1_size_cache));
+ e = xmalloc(sizeof(struct sha1_size_cache));
+ sha1_size_cache[first] = e;
+ memcpy(e->sha1, sha1, 20);
+ e->size = size;
+ return e;
+}
+
+/*
+ * While doing rename detection and pickaxe operation, we may need to
+ * grab the data for the blob (or file) for our own in-core comparison.
+ * diff_filespec has data and size fields for this purpose.
+ */
+int diff_populate_filespec(struct diff_filespec *s, int size_only)
+{
+ int err = 0;
+ if (!DIFF_FILE_VALID(s))
+ die("internal error: asking to populate invalid file.");
+ if (S_ISDIR(s->mode))
+ return -1;
+
+ if (!use_size_cache)
+ size_only = 0;
+
+ if (s->data)
+ return err;
+ if (!s->sha1_valid ||
+ work_tree_matches(s->path, s->sha1)) {
+ struct stat st;
+ int fd;
+ if (lstat(s->path, &st) < 0) {
+ if (errno == ENOENT) {
+ err_empty:
+ err = -1;
+ empty:
+ s->data = "";
+ s->size = 0;
+ return err;
+ }
+ }
+ s->size = st.st_size;
+ if (!s->size)
+ goto empty;
+ if (size_only)
+ return 0;
+ if (S_ISLNK(st.st_mode)) {
+ int ret;
+ s->data = xmalloc(s->size);
+ s->should_free = 1;
+ ret = readlink(s->path, s->data, s->size);
+ if (ret < 0) {
+ free(s->data);
+ goto err_empty;
+ }
+ return 0;
+ }
+ fd = open(s->path, O_RDONLY);
+ if (fd < 0)
+ goto err_empty;
+ s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
+ s->should_munmap = 1;
+ close(fd);
+ }
+ else {
+ char type[20];
+ struct sha1_size_cache *e;
+
+ if (size_only) {
+ e = locate_size_cache(s->sha1, 1, 0);
+ if (e) {
+ s->size = e->size;
+ return 0;
+ }
+ if (!sha1_file_size(s->sha1, &s->size))
+ locate_size_cache(s->sha1, 0, s->size);
+ }
+ else {
+ s->data = read_sha1_file(s->sha1, type, &s->size);
+ s->should_free = 1;
+ }
+ }
+ return 0;
+}
+
+void diff_free_filespec_data(struct diff_filespec *s)
+{
+ if (s->should_free)
+ free(s->data);
+ else if (s->should_munmap)
+ munmap(s->data, s->size);
+ s->should_free = s->should_munmap = 0;
+ s->data = NULL;
+}
+
+static void prep_temp_blob(struct diff_tempfile *temp,
+ void *blob,
+ unsigned long size,
+ unsigned char *sha1,
+ int mode)
+{
+ 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_filespec *one)
+{
+ if (!DIFF_FILE_VALID(one)) {
+ 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 ||
+ work_tree_matches(name, one->sha1)) {
+ struct stat st;
+ if (lstat(name, &st) < 0) {
+ if (errno == ENOENT)
+ goto not_a_valid_file;
+ die("stat(%s): %s", 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->sha1 : null_sha1),
+ (one->sha1_valid ?
+ one->mode : S_IFLNK));
+ }
+ else {
+ /* we can borrow from the file in the work tree */
+ temp->name = name;
+ if (!one->sha1_valid)
+ strcpy(temp->hex, sha1_to_hex(null_sha1));
+ else
+ strcpy(temp->hex, sha1_to_hex(one->sha1));
+ /* Even though we may sometimes borrow the
+ * contents from the work tree, we always want
+ * one->mode. mode is trustworthy even when
+ * !(one->sha1_valid), as long as
+ * DIFF_FILE_VALID(one).
+ */
+ sprintf(temp->mode, "%06o", one->mode);
+ }
+ return;
+ }
+ else {
+ if (diff_populate_filespec(one, 0))
+ die("cannot read data blob for %s", one->path);
+ prep_temp_blob(temp, one->data, one->size,
+ one->sha1, 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;
+ }
+}
+
+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 [ rename-to ]
+ *
+ */
+static void run_external_diff(const char *pgm,
+ const char *name,
+ const char *other,
+ struct diff_filespec *one,
+ struct diff_filespec *two,
+ const char *xfrm_msg)
+{
+ 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(other ? : 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) {
+ if (pgm) {
+ if (one && two) {
+ const char *exec_arg[10];
+ const char **arg = &exec_arg[0];
+ *arg++ = pgm;
+ *arg++ = name;
+ *arg++ = temp[0].name;
+ *arg++ = temp[0].hex;
+ *arg++ = temp[0].mode;
+ *arg++ = temp[1].name;
+ *arg++ = temp[1].hex;
+ *arg++ = temp[1].mode;
+ if (other) {
+ *arg++ = other;
+ *arg++ = xfrm_msg;
+ }
+ *arg = NULL;
+ execvp(pgm, (char *const*) exec_arg);
+ }
+ else
+ execlp(pgm, pgm, name, NULL);
+ }
+ /*
+ * otherwise we use the built-in one.
+ */
+ if (one && two)
+ builtin_diff(name, other ? : name, temp, xfrm_msg);
+ 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();
+}
+
+static void run_diff(const char *name,
+ const char *other,
+ struct diff_filespec *one,
+ struct diff_filespec *two,
+ const char *xfrm_msg)
+{
+ const char *pgm = external_diff();
+ if (!pgm &&
+ DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
+ (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
+ /* a filepair that changes between file and symlink
+ * needs to be split into deletion and creation.
+ */
+ struct diff_filespec *null = alloc_filespec(two->path);
+ run_external_diff(NULL, name, other, one, null, xfrm_msg);
+ free(null);
+ null = alloc_filespec(one->path);
+ run_external_diff(NULL, name, other, null, two, xfrm_msg);
+ free(null);
+ }
+ else
+ run_external_diff(pgm, name, other, one, two, xfrm_msg);
+}
+
+void diff_setup(int flags)
+{
+ if (flags & DIFF_SETUP_REVERSE)
+ reverse_diff = 1;
+ if (flags & DIFF_SETUP_USE_CACHE) {
+ if (!active_cache)
+ /* read-cache does not die even when it fails
+ * so it is safe for us to do this here. Also
+ * it does not smudge active_cache or active_nr
+ * when it fails, so we do not have to worry about
+ * cleaning it up oufselves either.
+ */
+ read_cache();
+ }
+ if (flags & DIFF_SETUP_USE_SIZE_CACHE)
+ use_size_cache = 1;
+
+}
+
+static int parse_num(const char **cp_p)
+{
+ int num, scale, ch, cnt;
+ const char *cp = *cp_p;
+
+ cnt = num = 0;
+ scale = 1;
+ while ('0' <= (ch = *cp) && ch <= '9') {
+ if (cnt++ < 5) {
+ /* We simply ignore more than 5 digits precision. */
+ scale *= 10;
+ num = num * 10 + ch - '0';
+ }
+ *cp++;
+ }
+ *cp_p = cp;
+
+ /* user says num divided by scale and we say internally that
+ * is MAX_SCORE * num / scale.
+ */
+ return (MAX_SCORE * num / scale);
+}
+
+int diff_scoreopt_parse(const char *opt)
+{
+ int opt1, opt2, cmd;
+
+ if (*opt++ != '-')
+ return -1;
+ cmd = *opt++;
+ if (cmd != 'M' && cmd != 'C' && cmd != 'B')
+ return -1; /* that is not a -M, -C nor -B option */
+
+ opt1 = parse_num(&opt);
+ if (cmd != 'B')
+ opt2 = 0;
+ else {
+ if (*opt == 0)
+ opt2 = 0;
+ else if (*opt != '/')
+ return -1; /* we expect -B80/99 or -B80 */
+ else {
+ opt++;
+ opt2 = parse_num(&opt);
+ }
+ }
+ if (*opt != 0)
+ return -1;
+ return opt1 | (opt2 << 16);
+}
+
+struct diff_queue_struct diff_queued_diff;
+
+void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
+{
+ if (queue->alloc <= queue->nr) {
+ queue->alloc = alloc_nr(queue->alloc);
+ queue->queue = xrealloc(queue->queue,
+ sizeof(dp) * queue->alloc);
+ }
+ queue->queue[queue->nr++] = dp;
+}
+
+struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
+ struct diff_filespec *one,
+ struct diff_filespec *two)
+{
+ struct diff_filepair *dp = xmalloc(sizeof(*dp));
+ dp->one = one;
+ dp->two = two;
+ dp->score = 0;
+ dp->source_stays = 0;
+ dp->broken_pair = 0;
+ diff_q(queue, dp);
+ return dp;
+}
+
+void diff_free_filepair(struct diff_filepair *p)
+{
+ diff_free_filespec_data(p->one);
+ diff_free_filespec_data(p->two);
+ free(p);
+}
+
+static void diff_flush_raw(struct diff_filepair *p,
+ int line_termination,
+ int inter_name_termination)
+{
+ int two_paths;
+ char status[10];
+
+ if (line_termination) {
+ const char *err = "path %s cannot be expressed without -z";
+ if (strchr(p->one->path, line_termination) ||
+ strchr(p->one->path, inter_name_termination))
+ die(err, p->one->path);
+ if (strchr(p->two->path, line_termination) ||
+ strchr(p->two->path, inter_name_termination))
+ die(err, p->two->path);
+ }
+
+ switch (p->status) {
+ case 'C': case 'R':
+ two_paths = 1;
+ sprintf(status, "%c%03d", p->status,
+ (int)(0.5 + p->score * 100.0/MAX_SCORE));
+ break;
+ case 'N': case 'D':
+ two_paths = 0;
+ if (p->score)
+ sprintf(status, "%c%03d", p->status,
+ (int)(0.5 + p->score * 100.0/MAX_SCORE));
+ else {
+ status[0] = p->status;
+ status[1] = 0;
+ }
+ break;
+ default:
+ two_paths = 0;
+ status[0] = p->status;
+ status[1] = 0;
+ break;
+ }
+ printf(":%06o %06o %s ",
+ p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
+ printf("%s %s%c%s",
+ sha1_to_hex(p->two->sha1),
+ status,
+ inter_name_termination,
+ p->one->path);
+ if (two_paths)
+ printf("%c%s", inter_name_termination, p->two->path);
+ putchar(line_termination);
+}
+
+int diff_unmodified_pair(struct diff_filepair *p)
+{
+ /* This function is written stricter than necessary to support
+ * the currently implemented transformers, but the idea is to
+ * let transformers to produce diff_filepairs any way they want,
+ * and filter and clean them up here before producing the output.
+ */
+ struct diff_filespec *one, *two;
+
+ if (DIFF_PAIR_UNMERGED(p))
+ return 0; /* unmerged is interesting */
+
+ one = p->one;
+ two = p->two;
+
+ /* deletion, addition, mode or type change
+ * and rename are all interesting.
+ */
+ if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
+ DIFF_PAIR_MODE_CHANGED(p) ||
+ strcmp(one->path, two->path))
+ return 0;
+
+ /* both are valid and point at the same path. that is, we are
+ * dealing with a change.
+ */
+ if (one->sha1_valid && two->sha1_valid &&
+ !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
+ return 1; /* no change */
+ if (!one->sha1_valid && !two->sha1_valid)
+ return 1; /* both look at the same file on the filesystem. */
+ return 0;
+}
+
+static void diff_flush_patch(struct diff_filepair *p)
+{
+ const char *name, *other;
+ char msg_[PATH_MAX*2+200], *msg;
+
+ if (diff_unmodified_pair(p))
+ return;
+
+ name = p->one->path;
+ other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+ if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
+ (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
+ return; /* no tree diffs in patch format */
+
+ switch (p->status) {
+ case 'C':
+ sprintf(msg_,
+ "similarity index %d%%\n"
+ "copy from %s\n"
+ "copy to %s",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE),
+ p->one->path, p->two->path);
+ msg = msg_;
+ break;
+ case 'R':
+ sprintf(msg_,
+ "similarity index %d%%\n"
+ "rename from %s\n"
+ "rename to %s",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE),
+ p->one->path, p->two->path);
+ msg = msg_;
+ break;
+ case 'D': case 'N':
+ if (DIFF_PAIR_BROKEN(p)) {
+ sprintf(msg_,
+ "dissimilarity index %d%%",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE));
+ msg = msg_;
+ }
+ else
+ msg = NULL;
+ break;
+ default:
+ msg = NULL;
+ }
+
+ if (DIFF_PAIR_UNMERGED(p))
+ run_diff(name, NULL, NULL, NULL, NULL);
+ else
+ run_diff(name, other, p->one, p->two, msg);
+}
+
+int diff_queue_is_empty(void)
+{
+ struct diff_queue_struct *q = &diff_queued_diff;
+ int i;
+ for (i = 0; i < q->nr; i++)
+ if (!diff_unmodified_pair(q->queue[i]))
+ return 0;
+ return 1;
+}
+
+#if DIFF_DEBUG
+void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
+{
+ fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
+ x, one ? : "",
+ s->path,
+ DIFF_FILE_VALID(s) ? "valid" : "invalid",
+ s->mode,
+ s->sha1_valid ? sha1_to_hex(s->sha1) : "");
+ fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
+ x, one ? : "",
+ s->size, s->xfrm_flags);
+}
+
+void diff_debug_filepair(const struct diff_filepair *p, int i)
+{
+ diff_debug_filespec(p->one, i, "one");
+ diff_debug_filespec(p->two, i, "two");
+ fprintf(stderr, "score %d, status %c stays %d broken %d\n",
+ p->score, p->status ? : '?',
+ p->source_stays, p->broken_pair);
+}
+
+void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
+{
+ int i;
+ if (msg)
+ fprintf(stderr, "%s\n", msg);
+ fprintf(stderr, "q->nr = %d\n", q->nr);
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ diff_debug_filepair(p, i);
+ }
+}
+#endif
+
+static void diff_resolve_rename_copy(void)
+{
+ int i, j;
+ struct diff_filepair *p, *pp;
+ struct diff_queue_struct *q = &diff_queued_diff;
+
+ diff_debug_queue("resolve-rename-copy", q);
+
+ for (i = 0; i < q->nr; i++) {
+ p = q->queue[i];
+ p->status = 0; /* undecided */
+ if (DIFF_PAIR_UNMERGED(p))
+ p->status = 'U';
+ else if (!DIFF_FILE_VALID(p->one))
+ p->status = 'N';
+ else if (!DIFF_FILE_VALID(p->two))
+ p->status = 'D';
+ else if (DIFF_PAIR_TYPE_CHANGED(p))
+ p->status = 'T';
+
+ /* from this point on, we are dealing with a pair
+ * whose both sides are valid and of the same type, i.e.
+ * either in-place edit or rename/copy edit.
+ */
+ else if (DIFF_PAIR_RENAME(p)) {
+ if (p->source_stays) {
+ p->status = 'C';
+ continue;
+ }
+ /* See if there is some other filepair that
+ * copies from the same source as us. If so
+ * we are a copy. Otherwise we are a rename.
+ */
+ for (j = i + 1; j < q->nr; j++) {
+ pp = q->queue[j];
+ if (strcmp(pp->one->path, p->one->path))
+ continue; /* not us */
+ if (!DIFF_PAIR_RENAME(pp))
+ continue; /* not a rename/copy */
+ /* pp is a rename/copy from the same source */
+ p->status = 'C';
+ break;
+ }
+ if (!p->status)
+ p->status = 'R';
+ }
+ else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
+ p->one->mode != p->two->mode)
+ p->status = 'M';
+ else {
+ /* This is a "no-change" entry and should not
+ * happen anymore, but prepare for broken callers.
+ */
+ error("feeding unmodified %s to diffcore",
+ p->one->path);
+ p->status = 'X';
+ }
+ }
+ diff_debug_queue("resolve-rename-copy done", q);
+}
+
+void diff_flush(int diff_output_style, int resolve_rename_copy)
+{
+ struct diff_queue_struct *q = &diff_queued_diff;
+ int i;
+ int line_termination = '\n';
+ int inter_name_termination = '\t';
+
+ if (diff_output_style == DIFF_FORMAT_MACHINE)
+ line_termination = inter_name_termination = 0;
+ if (resolve_rename_copy)
+ diff_resolve_rename_copy();
+
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
+ (p->status == 'X'))
+ continue;
+ if (p->status == 0)
+ die("internal error in diff-resolve-rename-copy");
+ switch (diff_output_style) {
+ case DIFF_FORMAT_PATCH:
+ diff_flush_patch(p);
+ break;
+ case DIFF_FORMAT_HUMAN:
+ case DIFF_FORMAT_MACHINE:
+ diff_flush_raw(p, line_termination,
+ inter_name_termination);
+ break;
+ }
+ }
+ for (i = 0; i < q->nr; i++)
+ diff_free_filepair(q->queue[i]);
+ free(q->queue);
+ q->queue = NULL;
+ q->nr = q->alloc = 0;
+}
+
+void diffcore_std(const char **paths,
+ int detect_rename, int rename_score,
+ const char *pickaxe, int pickaxe_opts,
+ int break_opt,
+ const char *orderfile)
+{
+ if (paths && paths[0])
+ diffcore_pathspec(paths);
+ if (break_opt != -1)
+ diffcore_break(break_opt);
+ if (detect_rename)
+ diffcore_rename(detect_rename, rename_score);
+ if (break_opt != -1)
+ diffcore_merge_broken();
+ if (pickaxe)
+ diffcore_pickaxe(pickaxe, pickaxe_opts);
+ if (orderfile)
+ diffcore_order(orderfile);
+}
+
+void diff_addremove(int addremove, unsigned mode,
+ const unsigned char *sha1,
+ const char *base, const char *path)
+{
+ char concatpath[PATH_MAX];
+ struct diff_filespec *one, *two;
+
+ /* This may look odd, but it is a preparation for
+ * feeding "there are unchanged files which should
+ * not produce diffs, but when you are doing copy
+ * detection you would need them, so here they are"
+ * entries to the diff-core. They will be prefixed
+ * with something like '=' or '*' (I haven't decided
+ * which but should not make any difference).
+ * Feeding the same new and old to diff_change()
+ * also has the same effect.
+ * Before the final output happens, they are pruned after
+ * merged into rename/copy pairs as appropriate.
+ */
+ if (reverse_diff)
+ addremove = (addremove == '+' ? '-' :
+ addremove == '-' ? '+' : addremove);
+
+ if (!path) path = "";
+ sprintf(concatpath, "%s%s", base, path);
+ one = alloc_filespec(concatpath);
+ two = alloc_filespec(concatpath);
+
+ if (addremove != '+')
+ fill_filespec(one, sha1, mode);
+ if (addremove != '-')
+ fill_filespec(two, sha1, mode);
+
+ diff_queue(&diff_queued_diff, one, two);
+}
+
+void diff_helper_input(unsigned old_mode,
+ unsigned new_mode,
+ const unsigned char *old_sha1,
+ const unsigned char *new_sha1,
+ const char *old_path,
+ int status,
+ int score,
+ const char *new_path)
+{
+ struct diff_filespec *one, *two;
+ struct diff_filepair *dp;
+
+ one = alloc_filespec(old_path);
+ two = alloc_filespec(new_path);
+ if (old_mode)
+ fill_filespec(one, old_sha1, old_mode);
+ if (new_mode)
+ fill_filespec(two, new_sha1, new_mode);
+ dp = diff_queue(&diff_queued_diff, one, two);
+ dp->score = score * MAX_SCORE / 100;
+ dp->status = status;
+}
+
+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_filespec *one, *two;
+
+ if (reverse_diff) {
+ unsigned tmp;
+ const unsigned char *tmp_c;
+ tmp = old_mode; old_mode = new_mode; new_mode = tmp;
+ tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
+ }
+ if (!path) path = "";
+ sprintf(concatpath, "%s%s", base, path);
+ one = alloc_filespec(concatpath);
+ two = alloc_filespec(concatpath);
+ fill_filespec(one, old_sha1, old_mode);
+ fill_filespec(two, new_sha1, new_mode);
+
+ diff_queue(&diff_queued_diff, one, two);
+}
+
+void diff_unmerge(const char *path)
+{
+ struct diff_filespec *one, *two;
+ one = alloc_filespec(path);
+ two = alloc_filespec(path);
+ diff_queue(&diff_queued_diff, one, two);
}