Direct users of IMPORTED targets treat INTERFACE_INCLUDE_DIRECTORIES
as SYSTEM, after commit a63fcbcb (Always consider includes from IMPORTED
targets to be SYSTEM., 2013-08-29). It was intended that transitive
use of an IMPORTED target would have the same behavior, but that
did not work. The implementation processed only direct dependencies
in cmTarget::FinalizeSystemIncludeDirectories.
Implement transitive evaluation of dependencies by traversing the
link interface of each target in the link implementation.
Transitively consume the property from linked dependents.
Implement configuration-specific support by following the pattern
set out for compile definitions and includes in cmQtAutoGenerators.
Implement support for origin-tracking with CMAKE_DEBUG_TARGET_PROPERTIES.
This is motivated by the needs of KDE, which provides a separate
translation system based on gettext instead of the Qt linguist
translation system. The Qt uic tool provides command line options
for configuring the method used to translate text, and to add an
include directive to the generated file to provide the method.
http://thread.gmane.org/gmane.comp.kde.devel.frameworks/7930/focus=7992
Implement the interface to provide the uic options as a usage-requirement
on the KI18n target, as designed for KDE.
9cf3547 Add the INTERFACE_SYSTEM_INCLUDE_DIRECTORIES target property.
1925cff Add a SYSTEM parameter to target_include_directories (#14180)
286f227 Extend the cmTargetPropCommandBase interface property handling.
83498d4 Store system include directories in the cmTarget.
f1fcbe3 Add Target API to determine if an include is a system include.
2679a34 Remove unused variable.
Unlike other target properties, this does not have a corresponding
non-INTERFACE variant.
This allows propagation of system attribute on include directories
from link dependents.
This property replaces the properties which
match (IMPORTED_)?LINK_INTERFACE_LIBRARIES(_<CONFIG>)?, and is enabled
for IMPORTED targets, and for non-IMPORTED targets only with a policy.
For static libraries, the INTERFACE_LINK_LIBRARIES property is
also used as the source of transitive usage requirements content.
Static libraries still require users to link to all entries in
their LINK_LIBRARIES, but usage requirements such as INCLUDE_DIRECTORIES
COMPILE_DEFINITIONS and COMPILE_OPTIONS can be restricted to only
certain interface libraries.
Because the INTERFACE_LINK_LIBRARIES property is populated unconditionally,
we need to compare the evaluated result of it with the link implementation
to determine whether to issue the policy warning for static libraries. For
shared libraries, the policy warning is issued if the contents of
the INTERFACE_LINK_LIBRARIES property differs from the contents of the
relevant config-specific old LINK_INTERFACE_LIBRARIES property.
Commit 089fe1c1 (Optimize genex evaluation for includes and
defines., 2013-02-01) introduced an optimization on DAG processing
to not reprocess properties on targets which have already been seen.
This was refactored slightly in commit 8dfdf1c7 (Fix the tests for
evaluating includes and defines., 2013-02-18), but was not extended
to cover COMPILE_OPTIONS in commit 80ca9c4b (Add COMPILE_OPTIONS target
property., 2013-05-16).
This omission causes the same performance regression in running
cmake on LLVM which 089fe1c1 fixed before, but this time for the
transitive evaluation of the COMPILE_OPTIONS property.
We should also check whether the INTERFACE_ variant of a property
is being read, and in the case of the compile definitions, we should
test the _<CONFIG> suffixed variants. That is already available
through the use of the methods.
This way, we use the ALREADY_SEEN optimization when evaluating
the includes of a target in 'external' generator expressions, ie, those
used in a add_custom_command invokation, as opposed to evaluating the
INCLUDE_DIRECTORIES of a target itself via GetIncludeDirectories.
Before this patch, the following is reported falsely as a self-reference:
target_link_libraries(empty2 LINK_PUBLIC empty3)
target_link_libraries(empty3 LINK_PUBLIC empty2)
add_custom_target(...
-DINCLUDES=$<TARGET_PROPERTY:empty2,INTERFACE_INCLUDE_DIRECTORIES>
)
The reason is that the existing code assumed that all reading of
include directories would be done through cmTarget::GetIncludeDirectories()
and would therefore be initialized with a DagChecker. That is not the case
if reading the property with an 'external' generator expression.
While porting boost to use these features, the generation step took
too long (several minutes before I stopped it). The reason was that
the boost libraries form a large interdependent mesh. The libraries
list their dependencies in their INTERFACE such as:
$<LINKED:boost::core>;$<LINKED:boost::config>;$<LINKED:boost::mpl>
As boost::core already depends on the boost::config libraries, that
expression has no impact on the end-content, as it is removed after
the generation step. There is no DAG issue though, so the generator
expression evaluation would fully evaluate them. In the case of the
config library, it also depends on the core library, so all depends
are followed through that again, despite the fact that they've just
been evaluated. After this patch, the evaluation skips libraries if
they have already been seen via depends or directly in the content.
This patch keeps track of targets whose INTERFACE has been consumed
already. The INCLUDE_DIRECTORIES and COMPILE_DEFINITIONS properties
are whitelisted because repeated content will be stripped out later
during generation. For other properties now and in the future, that
may not be the case.
These interface-related link-libraries properties are used to determine
the value of the other INTERFACE properties, so we were getting infinite
recursion and segfaults otherwise.
Constructs such as these are an error as they are direct self-references:
set_property(TARGET foo APPEND PROPERTY
INCLUDE_DIRECTORIES $<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>)
set_property(TARGET foo APPEND PROPERTY
INCLUDE_DIRECTORIES $<TARGET_PROPERTY:INCLUDE_DIRECTORIES>)
However, this is an indirect self-reference in a cycle, and not an error:
set_property(TARGET foo APPEND PROPERTY
INCLUDE_DIRECTORIES $<TARGET_PROPERTY:bar,INCLUDE_DIRECTORIES>)
set_property(TARGET bar APPEND PROPERTY
INCLUDE_DIRECTORIES $<TARGET_PROPERTY:foo,INCLUDE_DIRECTORIES>)
Stephen Kelly
Brad King