Remove use of UseObjectLibraries from Makefile and Ninja generators. It
is not needed now because those generators use GetExternalObjects
which already contains the objects from object libraries.
The VS10 generator calls both the UseObjectLibraries and the GetExternalObjects
methods. Ensure that duplicates are not created by skipping objects
from object libraries in handling of GetExternalObjects.
Similarly, fix VS6, VS7 and Xcode object handling by skipping
external objects from OBJECT_LIBRARY usage as appropriate.
The error message in the BadSourceExpression1 test is now reported
by the generator expression evaluator, so it has different text.
Teach cmGlobalGenerator::CheckTargets to include OBJECT_LIBRARY targets
in the check for source file existence.
Extend the RunCMake.ObjectLibrary test to cover this case.
It was a subtest of the RunCMake.ObjectLibrary test. However, we need
to test a build with ExternalProject after running CMake, which RunCMake tests
do not do.
Set the minimum required version of CMake high enough to avoid the
warning for CMAKE_LEGACY_CYGWIN_WIN32. The warning appears on stderr
and breaks the expected output matching.
Teach the RunCMake.ObjectLibrary test to verify that languages used in
an OBJECT library are propagated to targets that use it so that the
languages can be included in link analysis.
Add "RunCMake.ObjectLibrary" test to verify that unsupported use cases
are rejected with errors:
* An OBJECT library may not reference another object library
* An OBJECT library may not be referenced in target_link_libraries
* An OBJECT library may not contain non-compiling sources
* An OBJECT library may not have pre/post build/link commands
* An OBJECT library may not be installed, exported, or imported
Also verify that invalid $<TARGET_OBJECTS:...> expressions are
diagnosed.
Stephen Kelly
Brad King