This commit improves formatting and style of the documentation for the
general-purpose compiler check macros:
CHECK_C_COMPILER_FLAG
CHECK_C_SOURCE_COMPILES
CHECK_C_SOURCE_RUNS
CHECK_CXX_COMPILER_FLAG
CHECK_CXX_SOURCE_COMPILES
CHECK_CXX_SOURCE_RUNS
This sytle is more consistent with CMake command documentation.
It also looks nicer in the generated documentation text files.
the main project. I think it doesn't make sense if a project disables
RPATH, uses CHECK_C_SOURCE_RUNS() to see if something is able to run, and
this succeeds because it has been built with RPATH, but an executable built
within the project won't be able to run since it has been built without
RPATH.
Alex
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