From 4a2d2666a700740b314a71e0586a479f4b6cbc67 Mon Sep 17 00:00:00 2001
From: Frank Bergmann <fbergman@caltech.edu>
Date: Fri, 9 Aug 2024 13:35:09 +0200
Subject: [PATCH] Detect ZLIB using find module

---
 CMakeLists.txt | 71 +++++++-------------------------------------------
 1 file changed, 10 insertions(+), 61 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b2e97c6f4..8e1aeba36 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -534,68 +534,25 @@ Separate multiple directories using semicolons." )
 #
 # Locate zlib
 #
-
-set(ZLIB_INITIAL_VALUE)
-if (NOT LIBZ_LIBRARY)
-find_library(LIBZ_LIBRARY
-    NAMES zdll.lib z zlib.lib
-    PATHS /usr/lib /usr/local/lib
-          ${CMAKE_OSX_SYSROOT}/usr/lib
-          ${LIBSBML_DEPENDENCY_DIR}/lib
-          NO_DEFAULT_PATH
-          NO_CMAKE_ENVIRONMENT_PATH
-          NO_CMAKE_PATH
-          NO_SYSTEM_ENVIRONMENT_PATH
-          NO_CMAKE_SYSTEM_PATH
-          DOC "The file name of the zip compression library."
-    )
-endif()
-if (NOT LIBZ_LIBRARY)
-find_library(LIBZ_LIBRARY
-    NAMES zdll.lib z zlib.lib
-    PATHS /usr/lib /usr/local/lib
-          ${CMAKE_OSX_SYSROOT}/usr/lib
-          ${LIBSBML_DEPENDENCY_DIR}/lib
-    DOC "The file name of the zip compression library."
-    )
+find_package(ZLIB QUIET)
+set(ZLIB_INITIAL_VALUE ON)
+if(NOT TARGET ZLIB::ZLIB)
+set(ZLIB_INITIAL_VALUE OFF)
 endif()
 
-if(EXISTS ${LIBZ_LIBRARY})
-    set(ZLIB_INITIAL_VALUE ON)
-else()
-    set(ZLIB_INITIAL_VALUE OFF)
-endif()
 option(WITH_ZLIB     "Enable the use of zip compression."    ${ZLIB_INITIAL_VALUE} )
 
 set(USE_ZLIB OFF)
 if(WITH_ZLIB)
 
-  if (NOT LIBZ_INCLUDE_DIR)
-    find_path(LIBZ_INCLUDE_DIR
-        NAMES zlib.h zlib/zlib.h
-        PATHS ${CMAKE_OSX_SYSROOT}/usr/include
-              /usr/include /usr/local/include
-              ${LIBSBML_DEPENDENCY_DIR}/include
-              NO_DEFAULT_PATH
-        DOC "The directory containing the zlib include files."
-              )
-  endif()
-    if (NOT LIBZ_INCLUDE_DIR)
-        find_path(LIBZ_INCLUDE_DIR
-        NAMES zlib.h zlib/zlib.h
-        PATHS ${CMAKE_OSX_SYSROOT}/usr/include
-              /usr/include /usr/local/include
-              ${LIBSBML_DEPENDENCY_DIR}/include
-        DOC "The directory containing the zlib include files."
-              )
-    endif()
-    set(USE_ZLIB ON)
-    add_definitions( -DUSE_ZLIB )
+  find_package(ZLIB REQUIRED)
+  set(USE_ZLIB ON)
+  add_definitions( -DUSE_ZLIB )
   list(APPEND SWIG_EXTRA_ARGS -DUSE_ZLIB)
 
     # make sure that we have a valid zip library
-    file(TO_CMAKE_PATH "${LIBZ_LIBRARY}" LIBZ_CMAKE_PATH)
-    check_library_exists("${LIBZ_CMAKE_PATH}" "gzopen" "" LIBZ_FOUND_SYMBOL)
+    file(TO_CMAKE_PATH "${ZLIB_LIBRARY}" LIBZ_CMAKE_PATH)
+    check_library_exists("${LIBZ_CMAKE_PATH}" "gzopen" "" LIBZ_CMAKE_PATH)
     if(NOT LIBZ_FOUND_SYMBOL)
         # this is odd, but on windows this check always fails! must be a
         # bug in the current cmake version so for now only issue this
@@ -609,20 +566,12 @@ ${LIBSBML_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log")
         endif()
     endif()
 
-    if(NOT EXISTS "${LIBZ_INCLUDE_DIR}/zlib.h")
+    if(NOT EXISTS "${ZLIB_INCLUDE_DIR}/zlib.h")
         message(FATAL_ERROR
 "The include directory specified for zlib does not appear to be
 valid. It should contain the file zlib.h, but it does not.")
     endif()
 
-  if(NOT TARGET ZLIB::ZLIB)
-    add_library(ZLIB::ZLIB UNKNOWN IMPORTED)
-    set_target_properties(ZLIB::ZLIB PROPERTIES
-      IMPORTED_LINK_INTERFACE_LANGUAGES "C"
-      IMPORTED_LOCATION "${LIBZ_LIBRARY}"
-      INTERFACE_INCLUDE_DIRECTORIES "${LIBZ_INCLUDE_DIR}")
-  endif()
-
   list(APPEND LIBSBML_FIND_MODULES "${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules/FindZLIB.cmake")
 
 endif(WITH_ZLIB)