cmake: better zlib-ng / zlib handling

CMakeLists.txt

@@ -39,6 +39,16 @@ message(STATUS "Using CMake version ${CMAKE_VERSION}")
 option(MZ_COMPAT "Enables compatibility layer" ON)
 # Compression library options
 option(MZ_ZLIB "Enables ZLIB compression" ON)
+
+# Controls to select either zlib-ng or zlib
+set(MZ_ZLIB_FLAVOR "auto" CACHE STRING "Select the preferred zlib flavor - auto searches for zlib-ng then zlib")
+set(MZ_ZLIB_FLAVORS "auto" "zlib-ng" "zlib")
+set_property(CACHE MZ_ZLIB_FLAVOR PROPERTY STRINGS ${MZ_ZLIB_FLAVORS})
+
+if(NOT MZ_ZLIB_FLAVOR IN_LIST MZ_ZLIB_FLAVORS)
+    message(FATAL_ERROR "MZ_ZLIB_FLAVOR must be one of ${MZ_ZLIB_FLAVORS}")
+endif()
+
 option(MZ_BZIP2 "Enables BZIP2 compression" ON)
 option(MZ_LZMA "Enables LZMA & XZ compression" ON)
 option(MZ_ZSTD "Enables ZSTD compression" ON)
@@ -173,17 +183,21 @@ endif()
 if(MZ_ZLIB)
     # Check if zlib is present
     if(NOT MZ_FORCE_FETCH_LIBS)
-        find_package(ZLIBNG QUIET)
-        find_package(ZLIB QUIET)
+        if (MZ_ZLIB_FLAVOR STREQUAL "zlib-ng" OR MZ_ZLIB_FLAVOR STREQUAL "auto")
+            find_package(ZLIB-NG QUIET)
+        endif()
+        if (MZ_ZLIB_FLAVOR STREQUAL "zlib" OR MZ_ZLIB_FLAVOR STREQUAL "auto")
+            find_package(ZLIB QUIET)
+        endif()
         set(ZLIB_VERSION ${ZLIB_VERSION_STRING})
     endif()
 
-    if(ZLIBNG_FOUND AND NOT MZ_FORCE_FETCH_LIBS)
-        message(STATUS "Using ZLIBNG")
+    if(ZLIB-NG_FOUND AND NOT MZ_FORCE_FETCH_LIBS)
+        message(STATUS "Using ZLIB-NG")
 
-        list(APPEND MINIZIP_INC ${ZLIBNG_INCLUDE_DIRS})
-        list(APPEND MINIZIP_LIB ${ZLIBNG_LIBRARIES})
-        list(APPEND MINIZIP_LBD ${ZLIBNG_LIBRARY_DIRS})
+        list(APPEND MINIZIP_INC ${ZLIB-NG_INCLUDE_DIRS})
+        list(APPEND MINIZIP_LIB ${ZLIB-NG_LIBRARIES})
+        list(APPEND MINIZIP_LBD ${ZLIB-NG_LIBRARY_DIRS})
 
         set(PC_PRIVATE_DEPS "zlib-ng")
         set(ZLIB_COMPAT OFF)
@@ -215,7 +229,7 @@ if(MZ_ZLIB)
         endif()
 
         if(EXISTS "${ZLIB_BINARY_DIR}/zlib-ng.h")
-            message(STATUS "ZLIB repository detected as ZLIBNG")
+            message(STATUS "ZLIB repository detected as ZLIB-NG")
             set(ZLIB_COMPAT OFF)
         else()
             set(ZLIB_COMPAT ON)
@@ -231,8 +245,8 @@ if(MZ_ZLIB)
         if(ZLIB_COMPAT)
             list(APPEND MINIZIP_DEF -DZLIB_COMPAT)
         endif()
-        if(ZLIBNG_FOUND OR NOT ZLIB_COMPAT)
-            list(APPEND MINIZIP_DEP_PKG ZLIBNG)
+        if(ZLIB-NG_FOUND OR NOT ZLIB_COMPAT)
+            list(APPEND MINIZIP_DEP_PKG ZLIB-NG)
         elseif(ZLIB_FOUND)
             list(APPEND MINIZIP_DEP_PKG ZLIB)
         endif()

cmake/FindZLIB-NG.cmake

@@ -0,0 +1,32 @@
+find_path(ZLIB-NG_INCLUDE_DIRS NAMES zlib-ng.h)
+
+if(ZLIB_INCLUDE_DIRS)
+    set(ZLIB-NG_LIBRARY_DIRS ${ZLIB-NG_INCLUDE_DIRS})
+
+    if("${ZLIB-NG_LIBRARY_DIRS}" MATCHES "/include$")
+        # Strip off the trailing "/include" in the path.
+        get_filename_component(ZLIB-NG_LIBRARY_DIRS ${ZLIB-NG_LIBRARY_DIRS} PATH)
+    endif()
+
+    if(EXISTS "${ZLIB-NG_LIBRARY_DIRS}/lib")
+        set(ZLIB-NG_LIBRARY_DIRS ${ZLIB-NG_LIBRARY_DIRS}/lib)
+    endif()
+endif()
+
+find_library(ZLIB-NG_LIBRARY NAMES z-ng libz-ng libz-ng.a)
+
+set(ZLIB-NG_LIBRARIES ${ZLIB-NG_LIBRARY})
+set(ZLIB-NG_INCLUDE_DIRS ${ZLIB-NG_INCLUDE_DIRS})
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(ZLIB-NG DEFAULT_MSG ZLIB-NG_LIBRARY ZLIB-NG_INCLUDE_DIRS)
+
+if(ZLIB-NG_INCLUDE_DIRS AND ZLIB-NG_LIBRARIES)
+    set(ZLIB-NG_FOUND ON)
+else(ZLIB-NG_INCLUDE_DIRS AND ZLIB-NG_LIBRARIES)
+    set(ZLIB-NG_FOUND OFF)
+endif()
+
+if(ZLIB-NG_FOUND)
+    message(STATUS "Found zlib-ng: ${ZLIB-NG_LIBRARIES}, ${ZLIB-NG_INCLUDE_DIRS}")
+endif()