--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/updaterevision/updaterevision.c Thu Feb 06 22:11:45 2014 +0200
@@ -0,0 +1,136 @@
+/* updaterevision.c
+ *
+ * Public domain. This program uses git commands command to get
+ * various bits of repository status for a particular directory
+ * and writes it into a header file so that it can be used for a
+ * project's versioning.
+ */
+
+#define _CRT_SECURE_NO_DEPRECATE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+
+#ifdef _WIN32
+#define popen _popen
+#define pclose _pclose
+#endif
+
+// Used to strip newline characters from lines read by fgets.
+void stripnl(char *str)
+{
+ if (*str != '\0')
+ {
+ size_t len = strlen(str);
+ if (str[len - 1] == '\n')
+ {
+ str[len - 1] = '\0';
+ }
+ }
+}
+
+int main(int argc, char **argv)
+{
+ char vertag[64], lastlog[64], lasthash[64], *hash = NULL;
+ FILE *stream = NULL;
+ int gotrev = 0, needupdate = 1;
+
+ vertag[0] = '\0';
+ lastlog[0] = '\0';
+
+ if (argc != 2)
+ {
+ fprintf(stderr, "Usage: %s <path to gitinfo.h>\n", argv[0]);
+ return 1;
+ }
+
+ // Use git describe --tags to get a version string. If we are sitting directly
+ // on a tag, it returns that tag. Otherwise it returns <most recent tag>-<number of
+ // commits since the tag>-<short hash>.
+ // Use git log to get the time of the latest commit in ISO 8601 format and its full hash.
+ stream = popen("git describe --tags && git log -1 --format=%ai*%H", "r");
+
+ if (NULL != stream)
+ {
+ if (fgets(vertag, sizeof vertag, stream) == vertag &&
+ fgets(lastlog, sizeof lastlog, stream) == lastlog)
+ {
+ stripnl(vertag);
+ stripnl(lastlog);
+ gotrev = 1;
+ }
+
+ pclose(stream);
+ }
+
+ if (gotrev)
+ {
+ hash = strchr(lastlog, '*');
+ if (hash != NULL)
+ {
+ *hash = '\0';
+ hash++;
+ }
+ }
+ if (hash == NULL)
+ {
+ fprintf(stderr, "Failed to get commit info: %s\n", strerror(errno));
+ strcpy(vertag, "<unknown version>");
+ lastlog[0] = '\0';
+ lastlog[1] = '0';
+ lastlog[2] = '\0';
+ hash = lastlog + 1;
+ }
+
+ stream = fopen (argv[1], "r");
+ if (stream != NULL)
+ {
+ if (!gotrev)
+ { // If we didn't get a revision but the file does exist, leave it alone.
+ fclose (stream);
+ return 0;
+ }
+ // Read the revision that's in this file already. If it's the same as
+ // what we've got, then we don't need to modify it and can avoid rebuilding
+ // dependant files.
+ if (fgets(lasthash, sizeof lasthash, stream) == lasthash)
+ {
+ stripnl(lasthash);
+ if (strcmp(hash, lasthash + 3) == 0)
+ {
+ needupdate = 0;
+ }
+ }
+ fclose (stream);
+ }
+
+ if (needupdate)
+ {
+ stream = fopen (argv[1], "w");
+ if (stream == NULL)
+ {
+ return 1;
+ }
+ fprintf(stream,
+"// %s\n"
+"//\n"
+"// This file was automatically generated by the\n"
+"// updaterevision tool. Do not edit by hand.\n"
+"\n"
+"#define GIT_DESCRIPTION \"%s\"\n"
+"#define GIT_HASH \"%s\"\n"
+"#define GIT_TIME \"%s\"\n",
+ hash, vertag, hash, lastlog);
+ fclose(stream);
+ fprintf(stderr, "%s updated to commit %s.\n", argv[1], vertag);
+ }
+ else
+ {
+ fprintf (stderr, "%s is up to date at commit %s.\n", argv[1], vertag);
+ }
+
+ return 0;
+}