cmake: Create imported target for Boost, if it doesn't exist yet

Older versions of CMake's FindBoost.cmake don't create imported
targets for the library. Create it ourselves if necessary.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a27d1a6..9037c89 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -335,6 +335,14 @@ set_package_properties(Boost PROPERTIES TYPE REQUIRED
     URL "https://www.boost.org/"
     DESCRIPTION "Boost libraries for C++"
 )
     URL "https://www.boost.org/"
     DESCRIPTION "Boost libraries for C++"
 )

+# Older versions don't define the imported target
+if (NOT TARGET Boost::boost)
+    add_library(Boost::boost INTERFACE IMPORTED GLOBAL)
+    if (Boost_INCLUDE_DIRS)
+        set_target_properties(Boost::boost PROPERTIES
+            INTERFACE_INCLUDE_DIRECTORIES "${Boost_INCLUDE_DIRS}")
+    endif()
+endif()

 
 find_package(ZLIB REQUIRED)
 set_package_properties(ZLIB PROPERTIES TYPE REQUIRED
 
 find_package(ZLIB REQUIRED)
 set_package_properties(ZLIB PROPERTIES TYPE REQUIRED