FindThreads.h
BUG: improve CheckC(XX)SourceRuns.cmake so that it works with cross
compiling, the return value has to go in the cache but shouldn't overwrite
the actual return value, and it should go only in the cache if we have a
result from try_run() otherwise we won't get here again if we have a result
later on
Alex
variable is already added to the cache inside cmTryRunCommand.cxx, so the
value used here was ignored. Additionally the INTERNAL made it internal,
which shouldn't be done when cross compiling, since here the user is
required to edit this variable manually e.g. using ccmake.
Alex
creates two cache variables, one for the RUN_RESULT, one for the RUN_OUTPUT
(if required), which can be set or preset by the user. It has now also two
new arguments: RUN_OUTPUT_VARIABLE and COMPILE_OUTPUT_VARIABLE (the old
OUTPUT_VARIABLE merges both), so if only COMPILE_OUTPUT_VARIABLE is used the
run time output of the TRY_RUN is unused and the user doesn't have to care
about the output when crosscompiling. This is now used in FindThreads.cmake,
CheckC/CXXSourceRuns.cmake and TestBigEndian.cmake, which used the output
only for the logfile (compile output is still there). Test/TryCompile/ now
also tests the behaviour of OUTPUT_VARIABLE, RUN_OUTPUT_VARIABLE and
COMPILE_OUTPUT_VARIABLE.
Alex
Alexander Neundorf
Bill Hoffman