FILE_SET is incompatible with frameworks. Revert back to target_include_directories. :`(

Author: cboulay

cmake/Installation.cmake

@@ -4,11 +4,6 @@ include(CMakePackageConfigHelpers)
 # Paths
 if(LSL_UNIXFOLDERS)
     include(GNUInstallDirs)
-    if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
-        set(FRAMEWORK_DIR_DEFAULT Library/Frameworks)
-    else()
-        set(FRAMEWORK_DIR_DEFAULT Frameworks)
-    endif()
     set(CMAKE_INSTALL_FRAMEWORK_DIR ${FRAMEWORK_DIR_DEFAULT} CACHE PATH "Install directory for frameworks on macOS")
 else()
     set(CMAKE_INSTALL_BINDIR LSL)
@@ -48,8 +43,13 @@ install(TARGETS ${LSLTargets}
     LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
     ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
     FRAMEWORK DESTINATION ${CMAKE_INSTALL_FRAMEWORK_DIR}
-    FILE_SET HEADERS DESTINATION ${LSL_INSTALL_INCLUDEDIR}
 )
+# Unfortunately, `INCLUDES DESTINATION` does not work.
+# PUBLIC_HEADER does not work because it flattens the tree.
+# FILE_SET is preferable but does not work with frameworks.
+# So we are stuck manually specifying the headers to be installed.
+install(DIRECTORY include/lsl DESTINATION ${LSL_INSTALL_INCLUDEDIR})
+install(FILES include/lsl_c.h include/lsl_cpp.h DESTINATION ${LSL_INSTALL_INCLUDEDIR})
 
 # Generate the LSLConfig.cmake file and mark it for installation
 install(EXPORT LSLTargets

cmake/ProjectOptions.cmake

@@ -11,3 +11,11 @@ option(LSL_TOOLS "Build some experimental tools for in-depth tests" OFF)
 option(LSL_UNITTESTS "Build LSL library unit tests" OFF)
 option(LSL_FORCE_FANCY_LIBNAME "Add library name decorations (32/64/-debug)" OFF)
 mark_as_advanced(LSL_FORCE_FANCY_LIBNAME)
+
+# If we install to the system then we want the framework to land in
+# `Library/Frameworks`, otherwise (e.g., Homebrew) we want `Frameworks`
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+    set(FRAMEWORK_DIR_DEFAULT Library/Frameworks)
+else()
+    set(FRAMEWORK_DIR_DEFAULT Frameworks)
+endif()

cmake/TargetLib.cmake

@@ -31,12 +31,20 @@ target_link_libraries(lsl PRIVATE lslobj)
 
 # Set the include directories for the lsl target.
 # Note: We had to link lslobj as a PRIVATE dependency, therefore we must manually expose the include directories
-get_target_property(LSLOBJ_HEADERS lslobj HEADER_SET)
-target_sources(lsl
-    INTERFACE
-        FILE_SET HEADERS
-        BASE_DIRS include
-        FILES ${LSLOBJ_HEADERS}
+if(APPLE AND LSL_FRAMEWORK)
+    # For frameworks, the install interface needs to point into the framework bundle
+    if(LSL_UNIXFOLDERS)
+        set(LSL_INSTALL_INTERFACE_INCLUDE_DIR "${FRAMEWORK_DIR_DEFAULT}/lsl.framework/Versions/A/Headers")
+    else()
+        set(LSL_INSTALL_INTERFACE_INCLUDE_DIR "LSL/Frameworks/lsl.framework/Versions/A/Headers")
+    endif()
+else()
+    set(LSL_INSTALL_INTERFACE_INCLUDE_DIR "include")
+endif()
+target_include_directories(lsl
+    PUBLIC
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+        $<INSTALL_INTERFACE:${LSL_INSTALL_INTERFACE_INCLUDE_DIR}>
 )
 
 # Set compile definitions for lsl

cmake/TargetObjLib.cmake

@@ -1,18 +1,16 @@
 # Create object library so all files are only compiled once
 add_library(lslobj OBJECT
         ${lslsources}
-#        ${lslheaders}  # Headers are added later using FILE_SET
+        ${lslheaders}
 )
 
 # Set the includes/headers for the lslobj target
-# Note: We cannot use the PUBLIC_HEADER property of the target,
-#  because it flattens the include directories.
-# Note: IME, this approach is less error prone than target_include_directories
-target_sources(lslobj
-    INTERFACE
-        FILE_SET HEADERS  # special set name; implies TYPE.
-        BASE_DIRS include
-        FILES ${lslheaders}
+# Note: We cannot use PUBLIC_HEADER because it flattens the include tree upon install
+# Note: We cannot use FILE_SET because it is not compatible with HEADERS.
+target_include_directories(lslobj
+    PUBLIC
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+        $<INSTALL_INTERFACE:include> # For targets that link to the installed lslobj
 )
 
 # Link system libs