Re: [PATCH v2 3/7] unit-tests: do show relative file paths

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> Visual C interpolates `__FILE__` with the absolute _Windows_ path of
> the source file. GCC interpolates it with the relative path, and the
> tests even verify that.
> 
> So let's make sure that the unit tests only emit such paths.

> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>   t/unit-tests/test-lib.c | 52 +++++++++++++++++++++++++++++++++++++----
>   1 file changed, 48 insertions(+), 4 deletions(-)
> 
> diff --git a/t/unit-tests/test-lib.c b/t/unit-tests/test-lib.c
> index 70030d587ff..744e223ee98 100644
> --- a/t/unit-tests/test-lib.c
> +++ b/t/unit-tests/test-lib.c
> @@ -21,6 +21,46 @@ static struct {
>   	.result = RESULT_NONE,
>   };
>   
> +#ifndef _MSC_VER
> +#define make_relative(location) location
> +#else
> +/*
> + * Visual C interpolates the absolute Windows path for `__FILE__`,
> + * but we want to see relative paths, as verified by t0080.
> + */
> +#include "dir.h"
> +
> +static const char *make_relative(const char *location)
> +{
> +	static char prefix[] = __FILE__, buf[PATH_MAX], *p;
> +	static size_t prefix_len;
> +
> +	if (!prefix_len) {
> +		size_t len = strlen(prefix);
> +		const char *needle = "\\t\\unit-tests\\test-lib.c";
> +		size_t needle_len = strlen(needle);
> +
> +		if (len < needle_len || strcmp(needle, prefix + len - needle_len))
> +			die("unexpected suffix of '%s'", prefix);
> +
> +		/* let it end in a directory separator */
> +		prefix_len = len - needle_len + 1;
> +	}
> +
> +	/* 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 = '/';
> +
> +	return buf;
> +}
> +#endif
> +
>   static void msg_with_prefix(const char *prefix, const char *format, va_list ap)
>   {
>   	fflush(stderr);
> @@ -147,7 +187,8 @@ int test__run_end(int was_run UNUSED, const char *location, const char *format,
>   			break;
>   
>   		case RESULT_NONE:
> -			test_msg("BUG: test has no checks at %s", location);
> +			test_msg("BUG: test has no checks at %s",
> +				 make_relative(location));
>   			printf("not ok %d", ctx.count);
>   			print_description(format, ap);
>   			ctx.result = RESULT_FAILURE;
> @@ -193,13 +234,15 @@ int test_assert(const char *location, const char *check, int ok)
>   	assert(ctx.running);
>   
>   	if (ctx.result == RESULT_SKIP) {
> -		test_msg("skipping check '%s' at %s", check, location);
> +		test_msg("skipping check '%s' at %s", check,
> +			 make_relative(location));
>   		return 0;
>   	} else if (!ctx.todo) {
>   		if (ok) {
>   			test_pass();
>   		} else {
> -			test_msg("check \"%s\" failed at %s", check, location);
> +			test_msg("check \"%s\" failed at %s", check,
> +				 make_relative(location));
>   			test_fail();
>   		}
>   	}
> @@ -224,7 +267,8 @@ int test__todo_end(const char *location, const char *check, int res)
>   	if (ctx.result == RESULT_SKIP)
>   		return 0;
>   	if (!res) {
> -		test_msg("todo check '%s' succeeded at %s", check, location);
> +		test_msg("todo check '%s' succeeded at %s", check,
> +			 make_relative(location));
>   		test_fail();
>   	} else {
>   		test_todo();