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.
When building on Cygwin without -mwin32, the _WIN32 macro may not be
defined. SharedForward must still set the PATH environment variable to
ensure runtime dependencies are found.
The 'ldd' wrapping feature uses 'cygcheck' for now since a real ldd tool
is not available in Cygwin 1.5. We can change to use the real ldd when
we choose to stop supporting legacy Cygwin and require 1.7.
When kwsys is built using GCC visibility support can be used. This is similar
to the way that Windows exports symbols in DLLs, and requires projects that
build kwsys to change the default visibility using some compiler flags. See
http://gcc.gnu.org/wiki/Visibility for more details about GCC visibility.
The SharedForward header contains a preprocessor table mapping from
platform to equivalents for ldd and LD_LIBRARY_PATH. This commit fixes
the table preprocessor directives to guarantee at most one platform.
This generalizes the commit "Fix compilation of VTK on debian/sparc".
The TestSharedForward executable and TestDynload module do not actually
link to a KWSys library, but it is nice to build them after the
libraries just like all other test binaries.
This also works around a universal binary bug in Xcode 2.x. It forgets
to create the output directory for the executable before linking it. We
avoid the problem by putting the library in the directory first.
KWSys should not set variables outside its namespace. It can honor the
EXECUTABLE_OUTPUT_PATH set by a host project, but tere is no need for it
to set a default in the host project cache.
In order to kill process trees we need to list all processes to find
those whose parent we are killing. We implement process listing on
OpenSolaris by using "ps -ef" and parsing the resulting format:
UID PID PPID C STIME TTY TIME CMD
%*s %d %d %*[^\n]\n
In order to kill process trees we need to list all processes to find
those whose parent we are killing. We implement process listing on QNX
using "ps -Af" and parsing the resulting format:
UID PID PPID C STIME TTY TIME CMD
%*d %d %d %*[^\n]\n
We enumerate processes to identify those whose parent is being killed so
that we can recursively kill the children. Enumeration uses the
Process32(First|Next) windows API functions, which accept PROCESSENTRY32
objects to be filled. This commit corrects the declaration of the entry
structure to account for its size on 64-bit Windows.
On UNIX systems we kill a tree of processes by performing a DFS walk of
the tree. We send SIGSTOP to each process encountered, recursively
handle its children, and then send SIGKILL.
We once used the above approach in the past, but it was removed by the
commit "Do not send both SIGSTOP and SIGKILL when killing a process".
The commit was meant to work-around an OS X 10.3 bug in which the child
would not always honor SIGKILL after SIGSTOP. At the time we wrongly
assumed that the process tree remains intact after SIGKILL and before
the child is reaped. In fact the grandchildren may be re-parented to
ppid=1 even before the child is reaped, which causes the DFS walk to
miss them.
KWSys Robot
Brad King
Dave Partyka
Marcus Hanwell
David Cole