Add "cvs2git" program to convert a CVS archive into a GIT archive
[git] / cvs2git.c
1 /*
2  * cvs2git
3  *
4  * Copyright (C) Linus Torvalds 2005
5  */
6
7 #include <stdio.h>
8 #include <ctype.h>
9 #include <string.h>
10 #include <stdlib.h>
11 #include <unistd.h>
12
13 static int verbose = 0;
14
15 /*
16  * This is a really stupid program that takes cvsps output, and
17  * generates a a long _shell_script_ that will create the GIT archive
18  * from it. 
19  *
20  * You've been warned. I told you it was stupid.
21  *
22  * NOTE NOTE NOTE! In order to do branches correctly, this needs
23  * the fixed cvsps that has the "Ancestor branch" tag output.
24  * Hopefully David Mansfield will update his distribution soon
25  * enough (he's the one who wrote the patch, so at least we don't
26  * have to figt maintainer issues ;)
27  */
28 enum state {
29         Header,
30         Log,
31         Members
32 };
33
34 static char *rcsdir;
35
36 static char date[100];
37 static char author[100];
38 static char branch[100];
39 static char ancestor[100];
40 static char tag[100];
41 static char log[32768];
42 static int loglen = 0;
43 static int initial_commit = 1;
44
45 static void lookup_author(char *n, char **name, char **email)
46 {
47         /*
48          * FIXME!!! I'm lazy and stupid.
49          *
50          * This could be something like
51          *
52          *      printf("lookup_author '%s'\n", n);
53          *      *name = "$author_name";
54          *      *email = "$author_email";
55          *
56          * and that would allow the script to do its own
57          * lookups at run-time.
58          */
59         *name = n;
60         *email = n;
61 }
62
63 static void prepare_commit(void)
64 {
65         char *author_name, *author_email;
66         char *src_branch;
67
68         lookup_author(author, &author_name, &author_email);
69
70         printf("export GIT_COMMITTER_NAME=%s\n", author_name);
71         printf("export GIT_COMMITTER_EMAIL=%s\n", author_email);
72
73         printf("export GIT_AUTHOR_NAME=%s\n", author_name);
74         printf("export GIT_AUTHOR_EMAIL=%s\n", author_email);
75
76         printf("export GIT_AUTHOR_DATE='%s'\n", date);
77
78         if (initial_commit)
79                 return;
80
81         src_branch = *ancestor ? ancestor : branch;
82         if (!strcmp(src_branch, "HEAD"))
83                 src_branch = "master";
84         printf("ln -sf refs/heads/'%s' .git/HEAD\n", src_branch);
85         printf("git-read-tree -m HEAD\n");
86         printf("git-checkout-cache -f -u -a\n");
87 }
88
89 static void commit(void)
90 {
91         const char *cmit_parent = initial_commit ? "" : "-p HEAD";
92
93         printf("tree=$(git-write-tree)\n");
94         printf("cat > .cmitmsg <<EOFMSG\n%s\nEOFMSG\n", log);
95         printf("commit=$(cat .cmitmsg | git-commit-tree $tree %s)\n", cmit_parent);
96         printf("echo $commit > .git/HEAD\n");
97
98         *date = 0;
99         *author = 0;
100         *branch = 0;
101         *ancestor = 0;
102         *tag = 0;
103         loglen = 0;
104
105         initial_commit = 0;
106 }
107
108 static void get_rcs_name(char *rcspathname, char *name, char *dir)
109 {
110         sprintf(rcspathname, "%s/%s,v", rcsdir, name);
111         if (!access(rcspathname, R_OK))
112                 return;
113
114         sprintf(rcspathname, "%s/Attic/%s,v", rcsdir, name);
115         if (!access(rcspathname, R_OK))
116                 return;
117
118         if (dir) {
119                 sprintf(rcspathname, "%s/%.*s/Attic/%s,v", rcsdir, (int)(dir - name), name, dir+1);
120                 if (!access(rcspathname, R_OK))
121                         return;
122         }
123         fprintf(stderr, "Unable to find RCS file for %s\n", name);
124         exit(1);
125 }
126
127 static void update_file(char *line)
128 {
129         static char rcspathname[4096];
130         char *name, *version;
131         char *dir;
132
133         while (isspace(*line))
134                 line++;
135         name = line;
136         line = strchr(line, ':');
137         if (!line)
138                 return;
139         *line++ = 0;
140         line = strchr(line, '>');
141         if (!line)
142                 return;
143         *line++ = 0;
144         version = line;
145         line = strchr(line, '(');
146         if (line) {     /* "(DEAD)" */
147                 printf("git-update-cache --force-remove '%s'\n", name);
148                 return;
149         }
150
151         dir = strrchr(name, '/');
152         if (dir)
153                 printf("mkdir -p %.*s\n", (int)(dir - name), name);
154
155         get_rcs_name(rcspathname, name, dir);
156                 
157         printf("co -p -r%s '%s' > '%s'\n", version, rcspathname, name);
158         printf("git-update-cache --add -- '%s'\n", name);
159 }
160
161 struct hdrentry {
162         const char *name;
163         char *dest;
164 } hdrs[] = {
165         { "Date:", date },
166         { "Author:", author },
167         { "Branch:", branch },
168         { "Ancestor branch:", ancestor },
169         { "Tag:", tag },
170         { "Log:", NULL },
171         { NULL, NULL }
172 };
173
174 int main(int argc, char **argv)
175 {
176         static char line[1000];
177         enum state state = Header;
178
179         rcsdir = getenv("RCSDIR");
180         if (!rcsdir) {
181                 fprintf(stderr, "I need an $RCSDIR\n");
182                 exit(1);
183         }
184
185         printf("[ -d .git ] && exit 1\n");
186         printf("git-init-db\n");
187         printf("mkdir -p .git/refs/heads\n");
188         printf("mkdir -p .git/refs/tags\n");
189         printf("ln -sf refs/heads/master .git/HEAD\n");
190
191         while (fgets(line, sizeof(line), stdin) != NULL) {
192                 int linelen = strlen(line);
193
194                 while (linelen && isspace(line[linelen-1]))
195                         line[--linelen] = 0;
196
197                 switch (state) {
198                 struct hdrentry *entry;
199
200                 case Header:
201                         if (verbose)
202                                 printf("# H: %s\n", line);
203                         for (entry = hdrs ; entry->name ; entry++) {
204                                 int len = strlen(entry->name);
205                                 char *val;
206
207                                 if (memcmp(entry->name, line, len))
208                                         continue;
209                                 if (!entry->dest) {
210                                         state = Log;
211                                         break;
212                                 }
213                                 val = line + len;
214                                 linelen -= len;
215                                 while (isspace(*val)) {
216                                         val++;
217                                         linelen--;
218                                 }
219                                 memcpy(entry->dest, val, linelen+1);
220                                 break;
221                         }
222                         continue;
223
224                 case Log:
225                         if (verbose)
226                                 printf("# L: %s\n", line);
227                         if (!strcmp(line, "Members:")) {
228                                 while (loglen && isspace(log[loglen-1]))
229                                         log[--loglen] = 0;
230                                 prepare_commit();
231                                 state = Members;
232                                 continue;
233                         }
234                                 
235                         if (loglen + linelen + 5 > sizeof(log))
236                                 continue;
237                         memcpy(log + loglen, line, linelen);
238                         loglen += linelen;
239                         log[loglen++] = '\n';
240                         continue;
241
242                 case Members:
243                         if (verbose)
244                                 printf("# M: %s\n", line);
245                         if (!linelen) {
246                                 commit();
247                                 state = Header;
248                                 continue;
249                         }
250                         update_file(line);
251                         continue;
252                 }
253         }
254         return 0;
255 }