[CMake] Link options not transitive

[Martin Krošlák]

Hi,

I have recently encountered what I believe might be a bug, where
INTERFACE_LINK_OPTIONS are not carried over static libraries.
Following is the simplest CMakeLists.txt that demonstrates the
problem:

cmake_minimum_required(VERSION 3.16)
project(LinkOptionsNotTransitive)
add_library(A SHARED A.cpp)
add_library(B STATIC B.cpp)
add_executable(C C.cpp)
target_link_options(A INTERFACE "/DELAYLOAD:A.dll")
target_link_libraries(B PRIVATE A)
target_link_libraries(C PRIVATE B)

I tested this with Visual Studio 2017 generator and both cmake 3.15.4
and 3.16.0-rc4, with the same result.

When inspecting generated solution, C is linking both A.lib and B.lib
(as it should), but /DELAYLOAD flag is not applied to it. If B has
PUBLIC dependency on A, then /DELAYLOAD flag is also correctly carried
over. I get the impression that target_link_options behaves as eg.
target_include_directories, which are not carried over PRIVATE
dependencies. Given that these are linker options, I would expect them
to follow same rules as target_link_libraries, which will carry over
until nearest linker invocation. Is there any reason for this
inconsistency, or is it just a bug and if so, what would be the best
way to report it?

-- 
Sincerely,
Martin Krošlák