[libcxx-commits] [PATCH] D120719: [runtimes] Always configure libc++abi before libc++

[Petr Hosek via Phabricator via libcxx-commits]

phosek added a comment.

In D120719#3380448 <https://reviews.llvm.org/D120719#3380448>, @ldionne wrote:

> In D120719#3376333 <https://reviews.llvm.org/D120719#3376333>, @phosek wrote:
>
>> @ldionne this is what I had in mind:
>>
>>   cmake_minimum_required(VERSION 3.13.4)
>>   project(Test C)
>>   
>>   add_library(A STATIC a.c)
>>   
>>   add_library(C SHARED c.c)
>>   target_link_libraries(C PRIVATE "$<GENEX_EVAL:$<TARGET_LINKER_FILE:B>>")
>>   
>>   add_library(B IMPORTED STATIC)
>>   set_target_properties(B PROPERTIES IMPORTED_LOCATION "$<TARGET_LINKER_FILE:A>")
>>
>> It seems to be working as expected in this minimal example.
>
> This is really clever, but the problem is that when you do `target_link_libraries(C PRIVATE "$<GENEX_EVAL:$<TARGET_LINKER_FILE:B>>")`, you lose the property of linking against the `B` target itself -- you're only linking against a specific `.dylib` or `.a` file, but you don't get all the target-level stuff like transitive `target_compile_definitions`, `target_include_directories` and so on, right? So for example, below `C` won't get the includes added by `B`:
>
>   cmake_minimum_required(VERSION 3.13.4)
>   project(Test C)
>   
>   add_library(A STATIC a.c)
>   
>   add_library(C SHARED c.c)
>   target_link_libraries(C PRIVATE "$<GENEX_EVAL:$<TARGET_LINKER_FILE:B>>") # This doesn't get `-I some/path/include`
>   
>   add_library(B IMPORTED STATIC)
>   target_include_directories(B INTERFACE "some/path/include")
>   set_target_properties(B PROPERTIES IMPORTED_LOCATION "$<TARGET_LINKER_FILE:A>")

You can use the same technique for include directories:

  cmake_minimum_required(VERSION 3.13.4)
  project(Test C)
  
  add_library(A STATIC a.c)
  target_include_directories(A PUBLIC "include/a")
  
  add_library(C SHARED c.c)
  target_link_libraries(C PRIVATE "$<GENEX_EVAL:$<TARGET_LINKER_FILE:B>>")
  target_include_directories(C PRIVATE "$<GENEX_EVAL:$<TARGET_PROPERTY:B,INCLUDE_DIRECTORIES>>")
  
  add_library(B IMPORTED STATIC)
  set_target_properties(B PROPERTIES IMPORTED_LOCATION "$<TARGET_LINKER_FILE:A>")
  set_target_properties(B PROPERTIES INCLUDE_DIRECTORIES "$<TARGET_PROPERTY:A,INCLUDE_DIRECTORIES>")

Is that what you had in mind?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D120719/new/

https://reviews.llvm.org/D120719