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-rw-r--r--versioncmp.c193
1 files changed, 193 insertions, 0 deletions
diff --git a/versioncmp.c b/versioncmp.c
new file mode 100644
index 0000000000..069ee94a4d
--- /dev/null
+++ b/versioncmp.c
@@ -0,0 +1,193 @@
+#include "cache.h"
+#include "config.h"
+#include "string-list.h"
+
+/*
+ * versioncmp(): copied from string/strverscmp.c in glibc commit
+ * ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding
+ * style. The implementation is under LGPL-2.1 and Git relicenses it
+ * to GPLv2.
+ */
+
+/*
+ * states: S_N: normal, S_I: comparing integral part, S_F: comparing
+ * fractionnal parts, S_Z: idem but with leading Zeroes only
+ */
+#define S_N 0x0
+#define S_I 0x3
+#define S_F 0x6
+#define S_Z 0x9
+
+/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
+#define CMP 2
+#define LEN 3
+
+static const struct string_list *prereleases;
+static int initialized;
+
+struct suffix_match {
+ int conf_pos;
+ int start;
+ int len;
+};
+
+static void find_better_matching_suffix(const char *tagname, const char *suffix,
+ int suffix_len, int start, int conf_pos,
+ struct suffix_match *match)
+{
+ /*
+ * A better match either starts earlier or starts at the same offset
+ * but is longer.
+ */
+ int end = match->len < suffix_len ? match->start : match->start-1;
+ int i;
+ for (i = start; i <= end; i++)
+ if (starts_with(tagname + i, suffix)) {
+ match->conf_pos = conf_pos;
+ match->start = i;
+ match->len = suffix_len;
+ break;
+ }
+}
+
+/*
+ * off is the offset of the first different character in the two strings
+ * s1 and s2. If either s1 or s2 contains a prerelease suffix containing
+ * that offset or a suffix ends right before that offset, then that
+ * string will be forced to be on top.
+ *
+ * If both s1 and s2 contain a (different) suffix around that position,
+ * their order is determined by the order of those two suffixes in the
+ * configuration.
+ * If any of the strings contains more than one different suffixes around
+ * that position, then that string is sorted according to the contained
+ * suffix which starts at the earliest offset in that string.
+ * If more than one different contained suffixes start at that earliest
+ * offset, then that string is sorted according to the longest of those
+ * suffixes.
+ *
+ * Return non-zero if *diff contains the return value for versioncmp()
+ */
+static int swap_prereleases(const char *s1,
+ const char *s2,
+ int off,
+ int *diff)
+{
+ int i;
+ struct suffix_match match1 = { -1, off, -1 };
+ struct suffix_match match2 = { -1, off, -1 };
+
+ for (i = 0; i < prereleases->nr; i++) {
+ const char *suffix = prereleases->items[i].string;
+ int start, suffix_len = strlen(suffix);
+ if (suffix_len < off)
+ start = off - suffix_len;
+ else
+ start = 0;
+ find_better_matching_suffix(s1, suffix, suffix_len, start,
+ i, &match1);
+ find_better_matching_suffix(s2, suffix, suffix_len, start,
+ i, &match2);
+ }
+ if (match1.conf_pos == -1 && match2.conf_pos == -1)
+ return 0;
+ if (match1.conf_pos == match2.conf_pos)
+ /* Found the same suffix in both, e.g. "-rc" in "v1.0-rcX"
+ * and "v1.0-rcY": the caller should decide based on "X"
+ * and "Y". */
+ return 0;
+
+ if (match1.conf_pos >= 0 && match2.conf_pos >= 0)
+ *diff = match1.conf_pos - match2.conf_pos;
+ else if (match1.conf_pos >= 0)
+ *diff = -1;
+ else /* if (match2.conf_pos >= 0) */
+ *diff = 1;
+ return 1;
+}
+
+/*
+ * Compare S1 and S2 as strings holding indices/version numbers,
+ * returning less than, equal to or greater than zero if S1 is less
+ * than, equal to or greater than S2 (for more info, see the texinfo
+ * doc).
+ */
+
+int versioncmp(const char *s1, const char *s2)
+{
+ const unsigned char *p1 = (const unsigned char *) s1;
+ const unsigned char *p2 = (const unsigned char *) s2;
+ unsigned char c1, c2;
+ int state, diff;
+
+ /*
+ * Symbol(s) 0 [1-9] others
+ * Transition (10) 0 (01) d (00) x
+ */
+ static const uint8_t next_state[] = {
+ /* state x d 0 */
+ /* S_N */ S_N, S_I, S_Z,
+ /* S_I */ S_N, S_I, S_I,
+ /* S_F */ S_N, S_F, S_F,
+ /* S_Z */ S_N, S_F, S_Z
+ };
+
+ static const int8_t result_type[] = {
+ /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
+
+ /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
+ /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
+ /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+ /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
+ };
+
+ if (p1 == p2)
+ return 0;
+
+ c1 = *p1++;
+ c2 = *p2++;
+ /* Hint: '0' is a digit too. */
+ state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
+
+ while ((diff = c1 - c2) == 0) {
+ if (c1 == '\0')
+ return diff;
+
+ state = next_state[state];
+ c1 = *p1++;
+ c2 = *p2++;
+ state += (c1 == '0') + (isdigit (c1) != 0);
+ }
+
+ if (!initialized) {
+ const struct string_list *deprecated_prereleases;
+ initialized = 1;
+ prereleases = git_config_get_value_multi("versionsort.suffix");
+ deprecated_prereleases = git_config_get_value_multi("versionsort.prereleasesuffix");
+ if (prereleases) {
+ if (deprecated_prereleases)
+ warning("ignoring versionsort.prereleasesuffix because versionsort.suffix is set");
+ } else
+ prereleases = deprecated_prereleases;
+ }
+ if (prereleases && swap_prereleases(s1, s2, (const char *) p1 - s1 - 1,
+ &diff))
+ return diff;
+
+ state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
+
+ switch (state) {
+ case CMP:
+ return diff;
+
+ case LEN:
+ while (isdigit (*p1++))
+ if (!isdigit (*p2++))
+ return 1;
+
+ return isdigit (*p2) ? -1 : diff;
+
+ default:
+ return state;
+ }
+}