The Config and IMPORTED_ variants may also contain generator
expressions.
If 'the implementation is the interface', then the result of
evaluating the expressions at generate time is used to populate
the IMPORTED_LINK_INTERFACE_LIBRARIES property.
1) In the case of non-static libraries, this is fine because the
user still has the option to populate the LINK_INTERFACE_LIBRARIES
with generator expressions if that is what is wanted.
2) In the case of static libraries, this prevents a footgun,
enforcing that the interface and the implementation are really
the same.
Otherwise, the LINK_LIBRARIES could contain a generator
expression which is evaluated with a different context at build
time, and when used as an imported target. That would mean that the
result of evaluating the INTERFACE_LINK_LIBRARIES property for
a static library would not necessarily be the 'link implementation'.
For example:
add_library(libone STATIC libone.cpp)
add_library(libtwo STATIC libtwo.cpp)
add_library(libthree STATIC libthree.cpp)
target_link_libraries(libtwo
$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,STATIC_LIBRARY>:libone>)
target_link_libraries(libthree libtwo)
If the LINK_LIBRARIES content was simply copied to the
IMPORTED_LINK_INTERFACE_LIBRARIES, then libthree links to libone, but
executables linking to libthree will not link to libone.
3) As the 'implementation is the interface' concept is to be
deprecated in the future anyway, this should be fine.
Now that we're processing a LINK_INTERFACE_LIBRARIES string, it
can contain targets. Make sure they are extracted for
namespacing purposes.
This needs to be restricted to strings which can actually have
targets named in them. For example, this is not done for
INTERFACE_COMPILE_DEFINITIONS, because even if there is a target
named 'foo', the string 'foo' in that property means that '-Dfoo'
will be set when compiling.
3581b96 Process the INTERFACE_PIC property from linked dependencies
042ecf0 Add API to calculate link-interface-dependent bool properties or error.
bf5ece5 Keep track of properties used to determine linker libraries.
0380f36 FindOpenGL: add Haiku paths
8e9630c FindGLUT: BeOS does not have libXi and libXmu
50bfedf FindLua51: do not try to link libm on BeOS
3d2e6a0 check for Haiku only with __HAIKU__
7a1b961 Haiku no longer defines __BEOS__
ed96d9a bootstrap: use better defaults for Haiku
This allows a dependee to inform a target that it should have its
POSITION_INDEPENDENT_CODE property set to ON, or OFF. The value of
the POSITION_INDEPENDENT_CODE property, if set, must be consistent
with any INTERFACE_POSITION_INDEPENDENT_CODE properties on dependees.
Add a test covering the consistency checks on platforms where they run.
This new method checks that the property FOO on a target is consistent
with the INTERFACE_FOO properties of its dependees. If they are not the
consistent, an error is reported. 'Consistent' means that iff the
property is set, it must have the same boolean value as all other
related properties.
This makes
set(CMAKE_BUILD_INTERFACE_INCLUDES ON)
add the equivalent of
set_property(TARGET tgt APPEND PROPERTY
INTERFACE_INCLUDE_DIRECTORIES
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR};${CMAKE_CURRENT_BINARY_DIR}>
)
to every target.
If the headers are in CMAKE_CURRENT_SOURCE_DIR, and the generated headers
are in CMAKE_CURRENT_BINARY_DIR, this is a convenient way to build a target
bar, which depends on foo, just by using target_link_libraries() and adding
the INTERFACE_INCLUDE_DIRECTORIES to the INCLUDE_DIRECTORIES of the target
being linked. There will be more-convenient porcelain API to consume the
property in the future.
This makes it possible to use:
target_link_libraries(foo LINK_INTERFACE_LIBRARIES bar)
where foo is an IMPORTED target. Other tll() signatures are not
allowed.
Previously we kept direct link dependencies in OriginalLinkLibraries.
The property exposes the information in the CMake language through the
get/set_property commands. We preserve the OriginalLinkLibraries value
internally to support old APIs like that for CMP0003's OLD behavior, but
the property is now authoritative. This follows up from commit d5cf644a
(Split link information processing into two steps, 2012-11-01).
This will be used later to populate the link interface properties when
exporting targets, and will later allow use of generator expressions
when linking to libraries with target_link_libraries.
Also make targets depend on the (config-specific) union of dependencies.
CMake now allows linking to dependencies or not depending on the config.
However, generated build systems are not all capable of processing
config-specific dependencies, so the targets depend on the union of
dependencies for all configs.
The 'head' is the dependent target to be linked with the current target.
It will be used to evaluate generator expressions with proper handling
of mapped configurations and is used as the source target of properties.
This requires that memoization is done with a key of a pair of target
and config, instead of just config, because now the result also depends
on the target. Removing the memoization entirely is not an option
because it slows cmake down considerably.
cc676c3 OS X: Detect implicit linker framework search paths
2dd67c7 OS X: Detect implicit link directories on modern toolchains
ba58d0c OS X: Link with all framework search paths, not just the last
894f52f Handle INTERFACE properties transitively for includes and defines.
f5b1980 Populate the ExportedTargets member early in GenerateMainFile
c67b812 Make cycles in target properties ignored, not an error.
d0f950f Use mapped config properties to evaluate $<CONFIG>
26def17 Make all relevant targets available in the genex context.
0c657dc Add API to populate INTERFACE properties in exported targets.
e04f737 Add API to extract target names from a genex string.
b0c8f73 Add the TARGET_NAME generator expression.
77475fe Allow generator expressions to require literals.
b2f1700 GenEx: Add expressions to specify build- or install-only values
Since commit 9a6ff950 (Fix for bug where VS2010 did not use .obj files as
part of the build, 2011-04-01) and commit b291d9e7 (VS10: Fix external
objects generated outside target, 2012-03-19) we try to detect whether an
external object file is also a custom command output in the same target.
This is because VS10 includes .obj custom command outputs on the link line
by default.
VS 11 supports a "<LinkObjects ...>false</LinkObjects>" setting in custom
command rules to tell VS not to link the outputs. From the VS help:
Specify whether the Inputs and output files with specific extensions (.obj,
.lib, .res, .rsc) are passed to the linker.
Treat all external object files the same and add "<Object>" settings for them.
The member variable is checked to determine whether to call
HandleMissingTarget(). As that could be called during the loop in
the comming commits, ensure that it contains all targets being
exported.
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>)
The TARGET_NAME expression, which requires a literal, provides
target names. $<TARGET_PROPERTY:tgt,prop> also provides target
names in the cases where tgt is a literal, so that TARGET_NAME is
not needed then in addition.
This is for specifying INCLUDE_DIRECTORIES relevant to the build-location
or the install location for example:
set_property(TARGET foo PROPERTY
INTERFACE_INCLUDE_DIRECTORIES
"$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR};${CMAKE_CURRENT_SOURCE_DIR}>"
"$<INSTALL_INTERFACE:${CMAKE_INSTALL_PREFIX}/include>"
)
A 'bar' target can then use:
set_property(TARGET bar PROPERTY
INCLUDE_DIRECTORIES
"$<TARGET_PROPERTY:foo,INTERFACE_INCLUDE_DIRECTORIES>"
)
and it will work whether foo is in the same project, or an imported target
from an installation location, or an imported target from a build location
generated by the export() command.
Because the generator expressions are only evaluated at build-time, these
new expressions are equivalent to the ZeroNode and OneNode.
The GeneratorExpression test is split into parts. Some shells can't run
the custom command as it is getting too long.
Stephen Kelly
Brad King
Kitware Robot
Rolf Eike Beer
Peter Kümmel