In commit 'Create KWSYS_PLATFORM_INFO_TEST macro' (2009-11-20) we
implemented the macro to use a cache entry to avoid re-running the
try_compile(). However, the output copied from the try_compile is
needed on every configure. If the user wipes out the build tree but not
the cache file then the try_compile() will not re-run to recreate the
needed file. We address the problem by teaching the macro to run the
try_compile() whenever its output file does not exist.
We store custom command rule hashes in CMakeFiles/CMakeRuleHashes.txt
persistently across CMake runs. When the rule hash changes we delete
the custom command output file and write a new hash into the persistence
file.
This functionality was first added by the commit 'Introduce "rule
hashes" to help rebuild files when rules change.' (2008-06-02).
However, the implementation in cmGlobalGenerator::CheckRuleHashes kept
the file open for read when attempting to rewrite a new file. On
Windows filesystems this prevented the new version of the file from
being written! This caused the first set of rule hashes to be used
forever within a build tree, meaning that all custom commands whose
rules changed would be rebuilt every time CMake regenerated the build
tree.
In this commit we address the problem by splitting the read and write
operations into separate methods. This ensures that the input stream is
closed before the output stream opens the file.
Commit "Teach CTest.Update tests to strongly check entries" (2010-02-09)
started checking Update.xml entries strongly. This revealed that some
cvs clients report "U CTestConfig.cmake" during update even though the
file did not change and it selects the same revision. As a result the
test fails with
Update.xml has extra unexpected entries:
Updated{CTestConfig.cmake}
We fix the test to tolerate this particular extra entry without failing.
In the CTest module we previously warned if the source directory did not
contain known version control directories. The message was:
"CTest cannot determine repository type. Please set UPDATE_TYPE
to 'cvs' or 'svn'. CTest update will not work."
This was confusing when building sources from a tarball. Furthermore,
we now support many more version control tools. This feature is now
mature enough that the warning causes confusion more than it provides
real help. We simply remove it.
We wrap the git executable in a shell script that touches one source
file after 'git pull'. This makes the file newer than the index even
though it has not actually changed. If CTest does not refresh the index
properly then the test will fail with a bogus modified file.
We use 'git diff-index' to detect local modifications after pull. On
some filesystems the work tree timestamps of a few files may be dated
after the index, making them appear as locally modified. We address the
problem by using 'git update-index --refresh' to refresh the index and
avoid false local modifications.
Previously these tests just checked for matching file names in the
Update.xml files. Now we check the update types (Updated, Modified, or
Conflicting) and reject unexpected extra entries.
Our internal path processing methods assume no trailing slashes, but bzr
adds trailing slashes to updated directories. This can lead to empty
entries in Update.xml files. We address the problem by stripping the
slashes as soon as they are parsed.
The compiler documents symbols _DF_VERSION_ and _VF_VERSION_ but they do
not seem to be available to the preprocessor. Instead we add a vendor
query table entry for Compaq. Running "f90 -what" produces
Compaq Visual Fortran Optimizing Compiler Version ...
This clearly identifies the compiler.
At least one Fortran compiler does not provide a preprocessor symbol to
identify itself. Instead we try running unknown compilers with version
query flags known for each vendor and look for known output. Future
commits will add vendor-specific flags/output table entries.
The PathScale compiler silently accepts unknown options that start in
more than one '-':
$ touch foo.c
$ pathcc -c foo.c --junk
$ echo $?
0
$ pathcc -c foo.c ---junk
$ echo $?
0
$ pathcc -c foo.c -junk
pathcc ERROR parsing -junk: unknown flag
$ echo $?
2
We teach the TryCompile to pass a bogus flag with only one '-' instead
of three '-'s for this compiler.