git-diff-tree: clean up output
[git] / diff-tree.c
1 #include <ctype.h>
2 #include "cache.h"
3 #include "diff.h"
4
5 static int silent = 0;
6 static int ignore_merges = 1;
7 static int recursive = 0;
8 static int read_stdin = 0;
9 static int line_termination = '\n';
10 static int generate_patch = 0;
11 static const char *header = NULL;
12
13 // What paths are we interested in?
14 static int nr_paths = 0;
15 static char **paths = NULL;
16 static int *pathlens = NULL;
17
18 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
19
20 static void update_tree_entry(void **bufp, unsigned long *sizep)
21 {
22         void *buf = *bufp;
23         unsigned long size = *sizep;
24         int len = strlen(buf) + 1 + 20;
25
26         if (size < len)
27                 die("corrupt tree file");
28         *bufp = buf + len;
29         *sizep = size - len;
30 }
31
32 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
33 {
34         int len = strlen(tree)+1;
35         const unsigned char *sha1 = tree + len;
36         const char *path = strchr(tree, ' ');
37
38         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
39                 die("corrupt tree file");
40         *pathp = path+1;
41         return sha1;
42 }
43
44 static char *malloc_base(const char *base, const char *path, int pathlen)
45 {
46         int baselen = strlen(base);
47         char *newbase = xmalloc(baselen + pathlen + 2);
48         memcpy(newbase, base, baselen);
49         memcpy(newbase + baselen, path, pathlen);
50         memcpy(newbase + baselen + pathlen, "/", 2);
51         return newbase;
52 }
53
54 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
55
56 /* A whole sub-tree went away or appeared */
57 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
58 {
59         while (size) {
60                 show_file(prefix, tree, size, base);
61                 update_tree_entry(&tree, &size);
62         }
63 }
64
65 /* A file entry went away or appeared */
66 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
67 {
68         unsigned mode;
69         const char *path;
70         const unsigned char *sha1 = extract(tree, size, &path, &mode);
71
72         if (header) {
73                 printf("%s", header);
74                 header = NULL;
75         }
76
77         if (silent)
78                 return;
79
80         if (recursive && S_ISDIR(mode)) {
81                 char type[20];
82                 unsigned long size;
83                 char *newbase = malloc_base(base, path, strlen(path));
84                 void *tree;
85
86                 tree = read_sha1_file(sha1, type, &size);
87                 if (!tree || strcmp(type, "tree"))
88                         die("corrupt tree sha %s", sha1_to_hex(sha1));
89
90                 show_tree(prefix, tree, size, newbase);
91                 
92                 free(tree);
93                 free(newbase);
94                 return;
95         }
96
97         if (generate_patch) {
98                 if (!S_ISDIR(mode))
99                         diff_addremove(prefix[0], mode, sha1, base, path);
100         }
101         else
102                 printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
103                        S_ISDIR(mode) ? "tree" : "blob",
104                        sha1_to_hex(sha1), base, path,
105                        line_termination);
106 }
107
108 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
109 {
110         unsigned mode1, mode2;
111         const char *path1, *path2;
112         const unsigned char *sha1, *sha2;
113         int cmp, pathlen1, pathlen2;
114         char old_sha1_hex[50];
115
116         sha1 = extract(tree1, size1, &path1, &mode1);
117         sha2 = extract(tree2, size2, &path2, &mode2);
118
119         pathlen1 = strlen(path1);
120         pathlen2 = strlen(path2);
121         cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
122         if (cmp < 0) {
123                 show_file("-", tree1, size1, base);
124                 return -1;
125         }
126         if (cmp > 0) {
127                 show_file("+", tree2, size2, base);
128                 return 1;
129         }
130         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
131                 return 0;
132
133         /*
134          * If the filemode has changed to/from a directory from/to a regular
135          * file, we need to consider it a remove and an add.
136          */
137         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
138                 show_file("-", tree1, size1, base);
139                 show_file("+", tree2, size2, base);
140                 return 0;
141         }
142
143         if (recursive && S_ISDIR(mode1)) {
144                 int retval;
145                 char *newbase = malloc_base(base, path1, pathlen1);
146                 retval = diff_tree_sha1(sha1, sha2, newbase);
147                 free(newbase);
148                 return retval;
149         }
150
151         if (header) {
152                 printf("%s", header);
153                 header = NULL;
154         }
155         if (silent)
156                 return 0;
157
158         if (generate_patch) {
159                 if (!S_ISDIR(mode1))
160                         diff_change(mode1, mode2, sha1, sha2, base, path1);
161         }
162         else {
163                 strcpy(old_sha1_hex, sha1_to_hex(sha1));
164                 printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
165                        S_ISDIR(mode1) ? "tree" : "blob",
166                        old_sha1_hex, sha1_to_hex(sha2), base, path1,
167                        line_termination);
168         }
169         return 0;
170 }
171
172 static int interesting(void *tree, unsigned long size, const char *base)
173 {
174         const char *path;
175         unsigned mode;
176         int i;
177         int baselen, pathlen;
178
179         if (!nr_paths)
180                 return 1;
181
182         (void)extract(tree, size, &path, &mode);
183
184         pathlen = strlen(path);
185         baselen = strlen(base);
186
187         for (i=0; i < nr_paths; i++) {
188                 const char *match = paths[i];
189                 int matchlen = pathlens[i];
190
191                 if (baselen >= matchlen) {
192                         /* If it doesn't match, move along... */
193                         if (strncmp(base, match, matchlen))
194                                 continue;
195
196                         /* The base is a subdirectory of a path which was specified. */
197                         return 1;
198                 }
199
200                 /* Does the base match? */
201                 if (strncmp(base, match, baselen))
202                         continue;
203
204                 match += baselen;
205                 matchlen -= baselen;
206
207                 if (pathlen > matchlen)
208                         continue;
209
210                 if (strncmp(path, match, pathlen))
211                         continue;
212
213                 return 1;
214         }
215         return 0; /* No matches */
216 }
217
218 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
219 {
220         while (size1 | size2) {
221                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
222                         update_tree_entry(&tree1, &size1);
223                         continue;
224                 }
225                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
226                         update_tree_entry(&tree2, &size2);
227                         continue;
228                 }
229                 if (!size1) {
230                         show_file("+", tree2, size2, base);
231                         update_tree_entry(&tree2, &size2);
232                         continue;
233                 }
234                 if (!size2) {
235                         show_file("-", tree1, size1, base);
236                         update_tree_entry(&tree1, &size1);
237                         continue;
238                 }
239                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
240                 case -1:
241                         update_tree_entry(&tree1, &size1);
242                         continue;
243                 case 0:
244                         update_tree_entry(&tree1, &size1);
245                         /* Fallthrough */
246                 case 1:
247                         update_tree_entry(&tree2, &size2);
248                         continue;
249                 }
250                 die("diff-tree: internal error");
251         }
252         return 0;
253 }
254
255 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
256 {
257         void *tree1, *tree2;
258         unsigned long size1, size2;
259         int retval;
260
261         tree1 = read_object_with_reference(old, "tree", &size1, 0);
262         if (!tree1)
263                 die("unable to read source tree (%s)", sha1_to_hex(old));
264         tree2 = read_object_with_reference(new, "tree", &size2, 0);
265         if (!tree2)
266                 die("unable to read destination tree (%s)", sha1_to_hex(new));
267         retval = diff_tree(tree1, size1, tree2, size2, base);
268         free(tree1);
269         free(tree2);
270         return retval;
271 }
272
273 static int diff_tree_stdin(char *line)
274 {
275         int len = strlen(line);
276         unsigned char commit[20], parent[20];
277         unsigned long size, offset;
278         static char this_header[100];
279         char *buf;
280
281         if (!len || line[len-1] != '\n')
282                 return -1;
283         line[len-1] = 0;
284         if (get_sha1_hex(line, commit))
285                 return -1;
286         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
287                 line[40] = 0;
288                 line[81] = 0;
289                 sprintf(this_header, "%s (from %s)\n", line, line+41);
290                 header = this_header;
291                 return diff_tree_sha1(parent, commit, "");
292         }
293         buf = read_object_with_reference(commit, "commit", &size, NULL);
294         if (!buf)
295                 return -1;
296
297         /* More than one parent? */
298         if (ignore_merges) {
299                 if (!memcmp(buf + 46 + 48, "parent ", 7))
300                         return 0;
301         }
302
303         line[40] = 0;
304         offset = 46;
305         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
306                 if (get_sha1_hex(buf + offset + 7, parent))
307                         return -1;
308                 sprintf(this_header, "%s (from %s)\n", line, sha1_to_hex(parent));
309                 header = this_header;
310                 diff_tree_sha1(parent, commit, "");
311                 offset += 48;
312         }
313         return -1;
314 }
315
316 static char *diff_tree_usage = "diff-tree [-p] [-r] [-z] <tree sha1> <tree sha1>";
317
318 int main(int argc, char **argv)
319 {
320         char line[1000];
321         unsigned char old[20], new[20];
322
323         for (;;) {
324                 char *arg;
325
326                 argv++;
327                 argc--;
328                 arg = *argv;
329                 if (!arg || *arg != '-')
330                         break;
331
332                 if (!strcmp(arg, "-")) {
333                         argv++;
334                         argc--;
335                         break;
336                 }
337                 if (!strcmp(arg, "-r")) {
338                         recursive = 1;
339                         continue;
340                 }
341                 if (!strcmp(arg, "-p")) {
342                         recursive = generate_patch = 1;
343                         continue;
344                 }
345                 if (!strcmp(arg, "-z")) {
346                         line_termination = '\0';
347                         continue;
348                 }
349                 if (!strcmp(arg, "-m")) {
350                         ignore_merges = 0;
351                         continue;
352                 }
353                 if (!strcmp(arg, "-s")) {
354                         silent = 1;
355                         continue;
356                 }
357                 if (!strcmp(arg, "--stdin")) {
358                         read_stdin = 1;
359                         continue;
360                 }
361                 usage(diff_tree_usage);
362         }
363
364         if (!read_stdin) {
365                 if (argc < 2 || get_sha1(argv[0], old) || get_sha1(argv[1], new))
366                         usage(diff_tree_usage);
367                 argv += 2;
368                 argc -= 2;
369         }
370
371         if (argc > 0) {
372                 int i;
373
374                 paths = argv;
375                 nr_paths = argc;
376                 pathlens = xmalloc(nr_paths * sizeof(int));
377                 for (i=0; i<nr_paths; i++)
378                         pathlens[i] = strlen(paths[i]);
379         }
380
381         if (!read_stdin)
382                 return diff_tree_sha1(old, new, "");
383
384         while (fgets(line, sizeof(line), stdin))
385                 diff_tree_stdin(line);
386
387         return 0;
388 }