Since some of the tests inherently produce platform-specific
results, we have provided a way to supply platform-specific result
comparison files. Frequently, the same variation applies to
multiple platforms; rather than supplying a separate comparison
file for every platform, there is a mapping file that defines
which comparison file to use. So, to eliminate bogus test
"failures" for a particular platform, you must choose
or make a variant result file, and then add a line to the mapping
file, which is resultmap.
Each line in the mapping file is of the form
testname/platformpattern=comparisonfilename
The test name is just the name of the particular regression test
module. The platform pattern is a pattern in the style of
expr (that is, a regular expression with an implicit
^ anchor
at the start). It is matched against the platform name as printed
by config.guess followed by
:gcc or :cc, depending on
whether you use the GNU compiler or the system's native compiler
(on systems where there is a difference). The comparison file
name is the name of the substitute result comparison file.
For example: some systems using older time zone libraries fail to apply
daylight-saving corrections to dates before 1970, causing
pre-1970 PDT times to be displayed in PST instead. This causes a
few differences in the horology regression test.
Therefore, we provide a variant comparison file,
horology-no-DST-before-1970.out, which includes
the results to be expected on these systems. To silence the bogus
"failure" message on HPPA platforms, resultmap
includes
horology/hppa=horology-no-DST-before-1970
which will trigger on any machine for which the output of config.guess
begins with "hppa". Other lines
in resultmap select the variant comparison file for other
platforms where it's appropriate.
