summaryrefslogtreecommitdiff
path: root/diff-cache.c
blob: 10d5c955743d5095b114185e06ba6724c5919e3e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
#include "cache.h"
#include "diff.h"
 
static int cached_only = 0;
static int diff_output_format = DIFF_FORMAT_HUMAN;
static int match_nonexisting = 0;
static int detect_rename = 0;
static int reverse_diff = 0;
static int diff_score_opt = 0;
static const char *pickaxe = NULL;
 
/* A file entry went away or appeared */
static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
{
	diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
}
 
static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
{
	unsigned char *sha1 = ce->sha1;
	unsigned int mode = ce->ce_mode;
 
	if (!cached_only) {
		static unsigned char no_sha1[20];
		int changed;
		struct stat st;
		if (lstat(ce->name, &st) < 0) {
			if (errno == ENOENT && match_nonexisting) {
				*sha1p = sha1;
				*modep = mode;
				return 0;
			}
			return -1;
		}
		changed = ce_match_stat(ce, &st);
		if (changed) {
			mode = create_ce_mode(st.st_mode);
			sha1 = no_sha1;
		}
	}
 
	*sha1p = sha1;
	*modep = mode;
	return 0;
}
 
static void show_new_file(struct cache_entry *new)
{
	unsigned char *sha1;
	unsigned int mode;
 
	/* New file in the index: it might actually be different in the working copy */
	if (get_stat_data(new, &sha1, &mode) < 0)
		return;
 
	show_file("+", new, sha1, mode);
}
 
static int show_modified(struct cache_entry *old,
			 struct cache_entry *new,
			 int report_missing)
{
	unsigned int mode, oldmode;
	unsigned char *sha1;
 
	if (get_stat_data(new, &sha1, &mode) < 0) {
		if (report_missing)
			show_file("-", old, old->sha1, old->ce_mode);
		return -1;
	}
 
	oldmode = old->ce_mode;
	if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
	    detect_rename < DIFF_DETECT_COPY)
		return 0;
 
	mode = ntohl(mode);
	oldmode = ntohl(oldmode);
 
	diff_change(oldmode, mode,
		    old->sha1, sha1, old->name, NULL);
	return 0;
}
 
static int diff_cache(struct cache_entry **ac, int entries)
{
	while (entries) {
		struct cache_entry *ce = *ac;
		int same = (entries > 1) && ce_same_name(ce, ac[1]);
 
		switch (ce_stage(ce)) {
		case 0:
			/* No stage 1 entry? That means it's a new file */
			if (!same) {
				show_new_file(ce);
				break;
			}
			/* Show difference between old and new */
			show_modified(ac[1], ce, 1);
			break;
		case 1:
			/* No stage 3 (merge) entry? That means it's been deleted */
			if (!same) {
				show_file("-", ce, ce->sha1, ce->ce_mode);
				break;
			}
			/* We come here with ce pointing at stage 1
			 * (original tree) and ac[1] pointing at stage
			 * 3 (unmerged).  show-modified with
			 * report-mising set to false does not say the
			 * file is deleted but reports true if work
			 * tree does not have it, in which case we
			 * fall through to report the unmerged state.
			 * Otherwise, we show the differences between
			 * the original tree and the work tree.
			 */
			if (!cached_only && !show_modified(ce, ac[1], 0))
				break;
			/* fallthru */
		case 3:
			diff_unmerge(ce->name);
			break;
 
		default:
			die("impossible cache entry stage");
		}
 
		/*
		 * Ignore all the different stages for this file,
		 * we've handled the relevant cases now.
		 */
		do {
			ac++;
			entries--;
		} while (entries && ce_same_name(ce, ac[0]));
	}
	return 0;
}
 
/*
 * This turns all merge entries into "stage 3". That guarantees that
 * when we read in the new tree (into "stage 1"), we won't lose sight
 * of the fact that we had unmerged entries.
 */
static void mark_merge_entries(void)
{
	int i;
	for (i = 0; i < active_nr; i++) {
		struct cache_entry *ce = active_cache[i];
		if (!ce_stage(ce))
			continue;
		ce->ce_flags |= htons(CE_STAGEMASK);
	}
}
 
static char *diff_cache_usage =
"git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [--cached] <tree-ish>";
 
int main(int argc, const char **argv)
{
	unsigned char tree_sha1[20];
	void *tree;
	unsigned long size;
	int ret;
 
	read_cache();
	while (argc > 2) {
		const char *arg = argv[1];
		argv++;
		argc--;
		if (!strcmp(arg, "-r")) {
			/* We accept the -r flag just to look like git-diff-tree */
			continue;
		}
		if (!strcmp(arg, "-p")) {
			diff_output_format = DIFF_FORMAT_PATCH;
			continue;
		}
		if (!strncmp(arg, "-M", 2)) {
			detect_rename = DIFF_DETECT_RENAME;
			diff_score_opt = diff_scoreopt_parse(arg);
			continue;
		}
		if (!strncmp(arg, "-C", 2)) {
			detect_rename = DIFF_DETECT_COPY;
			diff_score_opt = diff_scoreopt_parse(arg);
			continue;
		}
		if (!strcmp(arg, "-z")) {
			diff_output_format = DIFF_FORMAT_MACHINE;
			continue;
		}
		if (!strcmp(arg, "-R")) {
			reverse_diff = 1;
			continue;
		}
		if (!strcmp(arg, "-S")) {
			pickaxe = arg + 2;
			continue;
		}
		if (!strcmp(arg, "-m")) {
			match_nonexisting = 1;
			continue;
		}
		if (!strcmp(arg, "--cached")) {
			cached_only = 1;
			continue;
		}
		usage(diff_cache_usage);
	}
 
	if (argc < 2 || get_sha1(argv[1], tree_sha1))
		usage(diff_cache_usage);
	argv++;
	argc--;
 
	/* The rest is for paths restriction. */
 
	diff_setup(reverse_diff);
 
	mark_merge_entries();
 
	tree = read_object_with_reference(tree_sha1, "tree", &size, NULL);
	if (!tree)
		die("bad tree object %s", argv[1]);
	if (read_tree(tree, size, 1))
		die("unable to read tree object %s", argv[1]);
 
	ret = diff_cache(active_cache, active_nr);
	if (detect_rename)
		diffcore_rename(detect_rename, diff_score_opt);
	diffcore_prune();
	if (pickaxe)
		diffcore_pickaxe(pickaxe);
	if (2 <= argc)
		diffcore_pathspec(argv + 1);
	diff_flush(diff_output_format, 1);
	return ret;
}