"Modernize" FindZlib

Summary: reserved

Differential Revision: D68047031

CMakeLists.txt

@@ -132,7 +132,7 @@ target_link_libraries(redex-all
         ${STATIC_LINK_FLAG}
         ${Boost_LIBRARIES}
         ${REDEX_JSONCPP_LIBRARY}
-        ${REDEX_ZLIB_LIBRARY}
+        ZLIB::ZLIB
         ${CMAKE_DL_LIBS}
         redex
         resource

cmake_modules/Commons.cmake

@@ -45,8 +45,14 @@ macro(add_dependent_packages_for_redex)
             set(Boost_USE_STATIC_RUNTIME ON)
         endif()
         set(Boost_USE_MULTITHREADED ON)
+        set(ZLIB_USE_STATIC_LIBS ON)
     endif()
 
+    find_package(Zlib REQUIRED)
+
+    print_dirs("${ZLIB_INCLUDE_DIRS}" "ZLIB_INCLUDE_DIRS")
+    print_dirs("${ZLIB_LIBRARIES}" "ZLIB_LIBRARIES")
+
     find_package(Boost 1.71.0 REQUIRED COMPONENTS regex filesystem program_options iostreams thread)
     print_dirs("${Boost_INCLUDE_DIRS}" "Boost_INCLUDE_DIRS")
     print_dirs("${Boost_LIBRARIES}" "Boost_LIBRARIES")
@@ -73,20 +79,6 @@ macro(add_dependent_packages_for_redex)
         set(ZLIB_HOME "/usr/local/opt/zlib/")
     endif ()
 
-    find_package(Zlib REQUIRED)
-
-    print_dirs(${ZLIB_STATIC_LIB} "ZLIB_STATIC_LIB")
-    print_dirs(${ZLIB_SHARED_LIB} "ZLIB_SHARED_LIB")
-
-    if (ENABLE_STATIC)
-        set(REDEX_ZLIB_LIBRARY ${ZLIB_STATIC_LIB})
-    else ()
-        set(REDEX_ZLIB_LIBRARY ${ZLIB_SHARED_LIB})
-    endif ()
-
-    print_dirs("${ZLIB_INCLUDE_DIRS}" "ZLIB_INCLUDE_DIRS")
-    print_dirs("${REDEX_ZLIB_LIBRARY}" "REDEX_ZLIB_LIBRARY")
-
 endmacro()
 
 function(set_link_whole target_name lib_name)

cmake_modules/FindZlib.cmake

@@ -83,6 +83,24 @@ if (ZLIB_FOUND)
       message(STATUS "Found the ZLIB library: ${ZLIB_LIBRARIES}")
     endif ()
   endif ()
+
+  # Need to export as target as modern cmake does it.
+  set(ZLIB_INCLUDE_DIRS ${ZLIB_INCLUDE_DIR})
+
+  # Fix up ZLIB_LIBRARIES for the static result if necessary.
+  if (ZLIB_USE_STATIC_LIBS)
+    set(ZLIB_LIBRARIES ${ZLIB_STATIC_LIB})
+  else()
+    set(ZLIB_LIBRARIES ${ZLIB_SHARED_LIB})
+  endif()
+
+  if(NOT TARGET ZLIB::ZLIB)
+    add_library(ZLIB::ZLIB UNKNOWN IMPORTED)
+    set_target_properties(ZLIB::ZLIB PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES "${ZLIB_INCLUDE_DIRS}")
+    set_property(TARGET ZLIB::ZLIB APPEND PROPERTY
+      IMPORTED_LOCATION "${ZLIB_LIBRARIES}")
+  endif()
 else ()
   if (NOT ZLIB_FIND_QUIETLY)
     set(ZLIB_ERR_MSG "Could not find the ZLIB library. Looked in ")