On Saturday, February 10, 2024 9:06 PM, Junio C Hamano wrote:
><rsbecker@xxxxxxxxxxxxx> writes:
>
>> The diff appears to have failed because of an assumption of how paths
>> are resolved during compilation. The assumption is that files remain
>> partially qualified, which is not the case in all C compilers. This is
>> c99. My experience with gcc is that it qualifies names differently
>> than other compilers.
>
>I just found this bit of gem in t/unit-tests/test-lib.c. I guess Visual C
falls into the
>same category as yours, while GCC and Clang are from different camps?
>
>The easiest way forward may be to build on top of it, perhaps like so, to
generalize
>the make_relative() to cover your case, too?
>
> t/unit-tests/test-lib.c | 63
+++++++++++++++++++++++++++++++++++++---------
>---
> 1 file changed, 48 insertions(+), 15 deletions(-)
>
>diff --git c/t/unit-tests/test-lib.c w/t/unit-tests/test-lib.c index
>7bf9dfdb95..69dbe1bbc7 100644
>--- c/t/unit-tests/test-lib.c
>+++ w/t/unit-tests/test-lib.c
>@@ -21,45 +21,78 @@ static struct {
> .result = RESULT_NONE,
> };
>
>-#ifndef _MSC_VER
>-#define make_relative(location) location -#else
>+#include "dir.h"
> /*
> * Visual C interpolates the absolute Windows path for `__FILE__`,
> * but we want to see relative paths, as verified by t0080.
>+ * There are other compilers that do the same, and are not for
>+ * Windows.
> */
>-#include "dir.h"
>-
> static const char *make_relative(const char *location) {
> static char prefix[] = __FILE__, buf[PATH_MAX], *p;
> static size_t prefix_len;
>+ static int need_bs_to_fs = -1;
>
>- if (!prefix_len) {
>+ /* one-time preparation */
>+ if (need_bs_to_fs < 0) {
> size_t len = strlen(prefix);
>- const char *needle = "\\t\\unit-tests\\test-lib.c";
>+ char needle[] = "t\\unit-tests\\test-lib.c";
> size_t needle_len = strlen(needle);
>
>- if (len < needle_len || strcmp(needle, prefix + len -
needle_len))
>+ if (len < needle_len)
>+ die("unexpected prefix '%s'", prefix);
>+
>+ /*
>+ * The path could be relative (t/unit-tests/test-lib.c)
>+ * or full (/home/user/git/t/unit-tests/test-lib.c).
>+ * Check the slash between "t" and "unit-tests".
>+ */
>+ prefix_len = len - needle_len;
>+ if (prefix[prefix_len + 1] == '/') {
>+ /* Oh, we're not Windows */
>+ for (size_t i = 0; i < needle_len; i++)
>+ if (needle[i] == '\\')
>+ needle[i] = '/';
>+ need_bs_to_fs = 0;
>+ } else {
>+ need_bs_to_fs = 1;
>+ }
>+
>+ /*
>+ * prefix_len == 0 if the compiler gives paths relative
>+ * to the root of the working tree. Otherwise, we want
>+ * to see that we did find the needle[] at a directory
>+ * boundary.
>+ */
>+ if (fspathcmp(needle, prefix + prefix_len) ||
>+ (prefix_len &&
>+ prefix[prefix_len - 1] != '/' &&
>+ prefix[prefix_len - 1] != '\\'))
> die("unexpected suffix of '%s'", prefix);
>
>- /* let it end in a directory separator */
>- prefix_len = len - needle_len + 1;
> }
>
>+ /*
>+ * If our compiler gives relative paths and we do not need
>+ * to munge directory separator, we can return location as-is.
>+ */
>+ if (!prefix_len && !need_bs_to_fs)
>+ return location;
>+
> /* Does it not start with the expected prefix? */
> if (fspathncmp(location, prefix, prefix_len))
> return location;
>
> strlcpy(buf, location + prefix_len, sizeof(buf));
> /* convert backslashes to forward slashes */
>- for (p = buf; *p; p++)
>- if (*p == '\\')
>- *p = '/';
>-
>+ if (need_bs_to_fs) {
>+ for (p = buf; *p; p++)
>+ if (*p == '\\')
>+ *p = '/';
>+ }
> return buf;
> }
>-#endif
>
> static void msg_with_prefix(const char *prefix, const char *format,
va_list ap) {
This looks like a good plan.
--Randall
