X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=diff.c;h=e496905bad9853f912e1bbcc081c544524f8cb77;hb=23091e954c968282d4d9087da00f60c2f02aecc5;hp=804c08c2cf64b84dd259d0c9308818c9dfe59d6d;hpb=2e12a089ff1e011689f609aa1a687050a9de2ee4;p=git.git

diff --git a/diff.c b/diff.c
index 804c08c2..e496905b 100644
--- a/diff.c
+++ b/diff.c
@@ -8,8 +8,7 @@
 #include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
-
-static const char *diff_opts = "-pu";
+#include "xdiff/xdiff.h"
 
 static int use_size_cache;
 
@@ -69,25 +68,10 @@ static const char *external_diff(void)
 {
 	static const char *external_diff_cmd = NULL;
 	static int done_preparing = 0;
-	const char *env_diff_opts;
 
 	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_OPTS="-c";
-	 */
 	external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
-
-	/* In case external diff fails... */
-	env_diff_opts = getenv("GIT_DIFF_OPTS");
-	if (env_diff_opts) diff_opts = env_diff_opts;
-
 	done_preparing = 1;
 	return external_diff_cmd;
 }
@@ -101,13 +85,12 @@ static struct diff_tempfile {
 	char tmp_path[TEMPFILE_PATH_LEN];
 } diff_temp[2];
 
-static int count_lines(const char *filename)
+static int count_lines(const char *data, int size)
 {
-	FILE *in;
 	int count, ch, completely_empty = 1, nl_just_seen = 0;
-	in = fopen(filename, "r");
 	count = 0;
-	while ((ch = fgetc(in)) != EOF)
+	while (0 < size--) {
+		ch = *data++;
 		if (ch == '\n') {
 			count++;
 			nl_just_seen = 1;
@@ -117,7 +100,7 @@ static int count_lines(const char *filename)
 			nl_just_seen = 0;
 			completely_empty = 0;
 		}
-	fclose(in);
+	}
 	if (completely_empty)
 		return 0;
 	if (!nl_just_seen)
@@ -140,12 +123,11 @@ static void print_line_count(int count)
 	}
 }
 
-static void copy_file(int prefix, const char *filename)
+static void copy_file(int prefix, const char *data, int size)
 {
-	FILE *in;
 	int ch, nl_just_seen = 1;
-	in = fopen(filename, "r");
-	while ((ch = fgetc(in)) != EOF) {
+	while (0 < size--) {
+		ch = *data++;
 		if (nl_just_seen)
 			putchar(prefix);
 		putchar(ch);
@@ -154,107 +136,153 @@ static void copy_file(int prefix, const char *filename)
 		else
 			nl_just_seen = 0;
 	}
-	fclose(in);
 	if (!nl_just_seen)
 		printf("\n\\ No newline at end of file\n");
 }
 
 static void emit_rewrite_diff(const char *name_a,
 			      const char *name_b,
-			      struct diff_tempfile *temp)
+			      struct diff_filespec *one, 
+			      struct diff_filespec *two)
 {
 	/* Use temp[i].name as input, name_a and name_b as labels */
 	int lc_a, lc_b;
-	lc_a = count_lines(temp[0].name);
-	lc_b = count_lines(temp[1].name);
+	lc_a = count_lines(one->data, one->size);
+	lc_b = count_lines(two->data, two->size);
 	printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 	print_line_count(lc_a);
 	printf(" +");
 	print_line_count(lc_b);
 	printf(" @@\n");
 	if (lc_a)
-		copy_file('-', temp[0].name);
+		copy_file('-', one->data, one->size);
 	if (lc_b)
-		copy_file('+', temp[1].name);
+		copy_file('+', two->data, two->size);
+}
+
+static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
+{
+	if (!DIFF_FILE_VALID(one)) {
+		mf->ptr = ""; /* does not matter */
+		mf->size = 0;
+		return 0;
+	}
+	else if (diff_populate_filespec(one, 0))
+		return -1;
+	mf->ptr = one->data;
+	mf->size = one->size;
+	return 0;
+}
+
+struct emit_callback {
+	const char **label_path;
+};
+
+static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
+{
+	int i;
+	struct emit_callback *ecbdata = priv;
+
+	if (ecbdata->label_path[0]) {
+		printf("--- %s\n", ecbdata->label_path[0]);
+		printf("+++ %s\n", ecbdata->label_path[1]);
+		ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
+	}
+	for (i = 0; i < nbuf; i++)
+		if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
+			return -1;
+	return 0;
+}
+
+#define FIRST_FEW_BYTES 8000
+static int mmfile_is_binary(mmfile_t *mf)
+{
+	long sz = mf->size;
+	if (FIRST_FEW_BYTES < sz)
+		sz = FIRST_FEW_BYTES;
+	if (memchr(mf->ptr, 0, sz))
+		return 1;
+	return 0;
 }
 
 static void builtin_diff(const char *name_a,
 			 const char *name_b,
-			 struct diff_tempfile *temp,
+			 struct diff_filespec *one,
+			 struct diff_filespec *two,
 			 const char *xfrm_msg,
 			 int complete_rewrite)
 {
-	int i, next_at, cmd_size;
-	const char *const diff_cmd = "diff -L%s -L%s";
-	const char *const diff_arg  = "-- %s %s||:"; /* "||:" is to return 0 */
-	const char *input_name_sq[2];
-	const char *label_path[2];
-	char *cmd;
-
-	/* 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; we used to subtract 5 here, but we do not
-	 * care about small leaks in this subprocess that is about
-	 * to exec "diff" anymore.
-	 */
-	cmd_size = (strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg)
-		    + 128);
-
-	for (i = 0; i < 2; i++) {
-		input_name_sq[i] = sq_quote(temp[i].name);
-		if (!strcmp(temp[i].name, "/dev/null"))
-			label_path[i] = "/dev/null";
-		else if (!i)
-			label_path[i] = sq_quote(quote_two("a/", name_a));
-		else
-			label_path[i] = sq_quote(quote_two("b/", name_b));
-		cmd_size += (strlen(label_path[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, label_path[0], label_path[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 %s %s\n",
-	       quote_two("a/", name_a), quote_two("b/", name_b));
-	if (label_path[0][0] == '/') {
-		/* dev/null */
-		printf("new file mode %s\n", temp[1].mode);
+	mmfile_t mf1, mf2;
+	const char *lbl[2];
+	char *a_one, *b_two;
+
+	a_one = quote_two("a/", name_a);
+	b_two = quote_two("b/", name_b);
+	lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
+	lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
+	printf("diff --git %s %s\n", a_one, b_two);
+	if (lbl[0][0] == '/') {
+		/* /dev/null */
+		printf("new file mode %06o\n", two->mode);
 		if (xfrm_msg && xfrm_msg[0])
 			puts(xfrm_msg);
 	}
-	else if (label_path[1][0] == '/') {
-		printf("deleted file mode %s\n", temp[0].mode);
+	else if (lbl[1][0] == '/') {
+		printf("deleted file mode %06o\n", one->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 (one->mode != two->mode) {
+			printf("old mode %06o\n", one->mode);
+			printf("new mode %06o\n", two->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);
+		/*
+		 * we do not run diff between different kind
+		 * of objects.
+		 */
+		if ((one->mode ^ two->mode) & S_IFMT)
+			goto free_ab_and_return;
 		if (complete_rewrite) {
-			fflush(NULL);
-			emit_rewrite_diff(name_a, name_b, temp);
-			exit(0);
+			emit_rewrite_diff(name_a, name_b, one, two);
+			goto free_ab_and_return;
 		}
 	}
-	fflush(NULL);
-	execlp("/bin/sh","sh", "-c", cmd, NULL);
+
+	if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
+		die("unable to read files to diff");
+
+	if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
+		printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
+	else {
+		/* Crazy xdl interfaces.. */
+		const char *diffopts = getenv("GIT_DIFF_OPTS");
+		xpparam_t xpp;
+		xdemitconf_t xecfg;
+		xdemitcb_t ecb;
+		struct emit_callback ecbdata;
+
+		ecbdata.label_path = lbl;
+		xpp.flags = XDF_NEED_MINIMAL;
+		xecfg.ctxlen = 3;
+		xecfg.flags = XDL_EMIT_FUNCNAMES;
+		if (!diffopts)
+			;
+		else if (!strncmp(diffopts, "--unified=", 10))
+			xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
+		else if (!strncmp(diffopts, "-u", 2))
+			xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
+		ecb.outf = fn_out;
+		ecb.priv = &ecbdata;
+		xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+	}
+
+ free_ab_and_return:
+	free(a_one);
+	free(b_two);
+	return;
 }
 
 struct diff_filespec *alloc_filespec(const char *path)
@@ -272,7 +300,7 @@ void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 		   unsigned short mode)
 {
 	if (mode) {
-		spec->mode = DIFF_FILE_CANON_MODE(mode);
+		spec->mode = canon_mode(mode);
 		memcpy(spec->sha1, sha1, 20);
 		spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 	}
@@ -457,6 +485,8 @@ void diff_free_filespec_data(struct diff_filespec *s)
 		munmap(s->data, s->size);
 	s->should_free = s->should_munmap = 0;
 	s->data = NULL;
+	free(s->cnt_data);
+	s->cnt_data = NULL;
 }
 
 static void prep_temp_blob(struct diff_tempfile *temp,
@@ -559,6 +589,40 @@ static void remove_tempfile_on_signal(int signo)
 	raise(signo);
 }
 
+static int spawn_prog(const char *pgm, const char **arg)
+{
+	pid_t pid;
+	int status;
+
+	fflush(NULL);
+	pid = fork();
+	if (pid < 0)
+		die("unable to fork");
+	if (!pid) {
+		execvp(pgm, (char *const*) arg);
+		exit(255);
+	}
+
+	while (waitpid(pid, &status, 0) < 0) {
+		if (errno == EINTR)
+			continue;
+		return -1;
+	}
+
+	/* 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.
+	 */
+	if (WIFEXITED(status) && !WEXITSTATUS(status))
+		return 0;
+	return -1;
+}
+
 /* An external diff command takes:
  *
  * diff-cmd name infile1 infile1-sha1 infile1-mode \
@@ -573,11 +637,12 @@ static void run_external_diff(const char *pgm,
 			      const char *xfrm_msg,
 			      int complete_rewrite)
 {
+	const char *spawn_arg[10];
 	struct diff_tempfile *temp = diff_temp;
-	pid_t pid;
-	int status;
+	int retval;
 	static int atexit_asked = 0;
 	const char *othername;
+	const char **arg = &spawn_arg[0];
 
 	othername = (other? other : name);
 	if (one && two) {
@@ -592,59 +657,50 @@ static void run_external_diff(const char *pgm,
 		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);
+	if (one && two) {
+		*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;
 		}
-		/*
-		 * otherwise we use the built-in one.
-		 */
-		if (one && two)
-			builtin_diff(name, othername, temp, xfrm_msg,
-				     complete_rewrite);
-		else
-			printf("* Unmerged path %s\n", name);
-		exit(0);
+	} else {
+		*arg++ = pgm;
+		*arg++ = name;
 	}
-	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();
+	*arg = NULL;
+	retval = spawn_prog(pgm, spawn_arg);
+	remove_tempfile();
+	if (retval) {
 		fprintf(stderr, "external diff died, stopping at %s.\n", name);
 		exit(1);
 	}
-	remove_tempfile();
+}
+
+static void run_diff_cmd(const char *pgm,
+			 const char *name,
+			 const char *other,
+			 struct diff_filespec *one,
+			 struct diff_filespec *two,
+			 const char *xfrm_msg,
+			 int complete_rewrite)
+{
+	if (pgm) {
+		run_external_diff(pgm, name, other, one, two, xfrm_msg,
+				  complete_rewrite);
+		return;
+	}
+	if (one && two)
+		builtin_diff(name, other ? other : name,
+			     one, two, xfrm_msg, complete_rewrite);
+	else
+		printf("* Unmerged path %s\n", name);
 }
 
 static void diff_fill_sha1_info(struct diff_filespec *one)
@@ -676,8 +732,7 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 
 	if (DIFF_PAIR_UNMERGED(p)) {
 		/* unmerged */
-		run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
-				  0);
+		run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
 		return;
 	}
 
@@ -749,15 +804,15 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 		 * 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, 0);
+		run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
 		free(null);
 		null = alloc_filespec(one->path);
-		run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
+		run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
 		free(null);
 	}
 	else
-		run_external_diff(pgm, name, other, one, two, xfrm_msg,
-				  complete_rewrite);
+		run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
+			     complete_rewrite);
 
 	free(name_munged);
 	free(other_munged);