Otherwise, we get a separate IncludeDirectoriesEntry for each include,
and that causes unnecessary and confusing splitting in the output when
debugging the INCLUDE_DIRECTORIES property.
The cache here needs to be cleared if GetLinkInformation is called
at configure-time, such as during an export().
The next commit does exactly that, and without this patch,
the LinkLanguage test would fail.
It is not necessary and the current state is unintentional. Before
this patch,
target_link_libraries(foo bar)
causes the LINK_LIBRARIES property of foo to contain
$<TARGET_NAME:bar>
instead of just
bar
This new expression allows checking how a policy was set when a target
was created. That information is only recorded for a subset of policies,
so a whitelist is used.
1d74ba2 Test evaluation target via export for generator expressions
522bdac Export the INTERFACE_PIC property.
4ee872c Make the BUILD_INTERFACE of export()ed targets work.
1d47cd9 Add a test for the interfaces in targets exported from the build tree.
6c828f9 Move the exported check for file existence.
cfd4f0a Move the exported check for dependencies of targets
d8fe1fc Only generate one check per missing target.
f623d37 Don't write a comment in the export file without the code.
b279f2b Strip consecutive semicolons when preprocessing genex strings.
Don't add generator expressions to variables which are used
for CMP0003, CMP0004, and the old-style _LIB_DEPENDS content. They
will not be evaluated when read anyway and would probably confuse
the code reading them.
This makes it legitimate to use target_link_libraries with generator
expressions as arguments.
77d2646 Allow generator expressions in LINK_INTERFACE_LIBRARIES.
94aeaf7 Split LINK_INTERFACE_LIBRARIES export handling into dedicated method.
a3aedb8 Split the generator expression before extracting targets.
b6036d1 Extract the AddTargetNamespace method.
cb1afbf Don't pass a position when determining if a target name is a literal.
f99196d Add cmGeneratorExpression::Split() API.
In the implementation of "cmake -E cmake_link_script", skip lines from
the input file that are empty or contain only whitespace. Do not try to
run a child with no command line.
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.
