Build: Use imported target `ZLIB::ZLIB` instead of variables

Source/CMakeLists.txt

@@ -743,7 +743,6 @@ target_include_directories(
     "${CMake_BINARY_DIR}/Source"
     "${CMake_SOURCE_DIR}/Source"
     "${CMake_SOURCE_DIR}/Source/LexerParser"
-    ${CMAKE_ZLIB_INCLUDES}
     ${CMAKE_EXPAT_INCLUDES}
     ${CMAKE_TAR_INCLUDES}
     ${CMake_HAIKU_INCLUDE_DIRS}
@@ -753,8 +752,8 @@ target_link_libraries(
   PUBLIC
     cmstd
     cmsys
+    ZLIB::ZLIB
     ${CMAKE_EXPAT_LIBRARIES}
-    ${CMAKE_ZLIB_LIBRARIES}
     ${CMAKE_TAR_LIBRARIES}
     ${CMAKE_CURL_LIBRARIES}
     ${CMAKE_JSONCPP_LIBRARIES}

Source/Modules/CMakeBuildUtilities.cmake

@@ -114,18 +114,20 @@ endif()
 
 #---------------------------------------------------------------------
 # Build zlib library for Curl, CMake, and CTest.
-set(CMAKE_ZLIB_HEADER "cm_zlib.h")
 if(CMAKE_USE_SYSTEM_ZLIB)
   find_package(ZLIB)
   if(NOT ZLIB_FOUND)
     message(FATAL_ERROR
       "CMAKE_USE_SYSTEM_ZLIB is ON but a zlib is not found!")
   endif()
-  set(CMAKE_ZLIB_INCLUDES ${ZLIB_INCLUDE_DIR})
-  set(CMAKE_ZLIB_LIBRARIES ${ZLIB_LIBRARIES})
 else()
-  set(CMAKE_ZLIB_INCLUDES ${CMake_SOURCE_DIR}/Utilities)
-  set(CMAKE_ZLIB_LIBRARIES cmzlib)
+  if(NOT POLICY CMP0102) # CMake < 3.17
+    # Store in cache to protect from mark_as_advanced.
+    set(ZLIB_INCLUDE_DIR ${CMake_SOURCE_DIR}/Utilities CACHE PATH "")
+  else()
+    set(ZLIB_INCLUDE_DIR ${CMake_SOURCE_DIR}/Utilities)
+  endif()
+  set(ZLIB_LIBRARY cmzlib)
   set(WITHOUT_ZLIB_DLL "")
   set(WITHOUT_ZLIB_DLL_WITH_LIB cmzlib)
   set(ZLIB_DLL "")
@@ -134,6 +136,7 @@ else()
   set(ZLIB_WINAPI_COMPILED 0)
   set(ZLIB_WINAPI_WITH_LIB cmzlib)
   add_subdirectory(Utilities/cmzlib)
+  add_library(ZLIB::ZLIB ALIAS cmzlib)
   CMAKE_SET_TARGET_FOLDER(cmzlib "Utilities/3rdParty")
 endif()
 
@@ -148,9 +151,6 @@ if(CMAKE_USE_SYSTEM_CURL)
   set(CMAKE_CURL_INCLUDES ${CURL_INCLUDE_DIRS})
   set(CMAKE_CURL_LIBRARIES ${CURL_LIBRARIES})
 else()
-  set(CURL_SPECIAL_ZLIB_H ${CMAKE_ZLIB_HEADER})
-  set(CURL_SPECIAL_LIBZ_INCLUDES ${CMAKE_ZLIB_INCLUDES})
-  set(CURL_SPECIAL_LIBZ ${CMAKE_ZLIB_LIBRARIES})
   set(CMAKE_CURL_INCLUDES)
   set(CMAKE_CURL_LIBRARIES cmcurl)
   if(CMAKE_TESTS_CDASH_SERVER)
@@ -263,8 +263,6 @@ if(CMAKE_USE_SYSTEM_LIBARCHIVE)
 else()
   set(EXPAT_INCLUDE_DIR ${CMAKE_EXPAT_INCLUDES})
   set(EXPAT_LIBRARY ${CMAKE_EXPAT_LIBRARIES})
-  set(ZLIB_INCLUDE_DIR ${CMAKE_ZLIB_INCLUDES})
-  set(ZLIB_LIBRARY ${CMAKE_ZLIB_LIBRARIES})
   add_compile_definitions(LIBARCHIVE_STATIC)
   set(ENABLE_MBEDTLS OFF)
   set(ENABLE_NETTLE OFF)

Utilities/cmcurl/CMakeLists.txt

@@ -852,11 +852,11 @@ endif()
 # Check for symbol dlopen (same as HAVE_LIBDL)
 check_library_exists("${CURL_LIBS}" dlopen "" HAVE_DLOPEN)
 
-if(0) # This code not needed for building within CMake.
 set(HAVE_LIBZ OFF)
 set(HAVE_ZLIB_H OFF)
 set(USE_ZLIB OFF)
-optional_dependency(ZLIB)
+#optional_dependency(ZLIB)
+find_package(ZLIB)
 if(ZLIB_FOUND)
   set(HAVE_ZLIB_H ON)
   set(HAVE_LIBZ ON)
@@ -870,19 +870,8 @@ if(ZLIB_FOUND)
   else()
     list(APPEND CURL_LIBS ${ZLIB_LIBRARIES})
     include_directories(${ZLIB_INCLUDE_DIRS})
+    list(APPEND CMAKE_REQUIRED_INCLUDES ${ZLIB_INCLUDE_DIRS})
   endif()
-  list(APPEND CMAKE_REQUIRED_INCLUDES ${ZLIB_INCLUDE_DIRS})
-endif()
-endif()
-
-#-----------------------------------------------------------------------------
-# CMake-specific curl code.
-
-if(CURL_SPECIAL_LIBZ)
-  set(CURL_LIBS ${CURL_LIBS} "${CURL_SPECIAL_LIBZ}")
-  include_directories(${CURL_SPECIAL_LIBZ_INCLUDES})
-  set(HAVE_LIBZ 0)
-  set(HAVE_ZLIB_H 0)
 endif()
 
 option(CURL_BROTLI "Set to ON to enable building curl with brotli support." OFF)

Utilities/cmcurl/lib/content_encoding.c

@@ -27,7 +27,7 @@
 #include <stddef.h>
 
 #ifdef HAVE_ZLIB_H
-#include <zlib.h>
+#include <cm3p/zlib.h>
 #endif
 
 #ifdef HAVE_BROTLI

Utilities/cmcurl/lib/version.c

@@ -51,7 +51,7 @@
 #endif
 
 #ifdef HAVE_ZLIB_H
-#include <zlib.h>
+#include <cm3p/zlib.h>
 #endif
 
 #ifdef HAVE_BROTLI

Utilities/cmlibarchive/CMakeLists.txt

@@ -442,6 +442,8 @@ SET(ADDITIONAL_LIBS "")
 #
 IF(ENABLE_ZLIB)
   FIND_PACKAGE(ZLIB)
+  SET(ZLIB_INCLUDE_DIR "")
+  SET(ZLIB_LIBRARIES ZLIB::ZLIB)
 ELSE()
   SET(ZLIB_FOUND FALSE) # Override cached value
 ENDIF()