Merge pull request #895 from mavlink/revert-libz-cmake

Revert zlib patch for cmake config

third_party/zlib/CMakeLists.txt

@@ -18,9 +18,7 @@ ExternalProject_add(
     zlib
     GIT_REPOSITORY https://github.com/madler/zlib
     GIT_TAG v1.2.11
-    # Patch taken from: https://github.com/madler/zlib/pull/337/files
-    # Thanks to @Mizux
-    PATCH_COMMAND git apply ${PROJECT_SOURCE_DIR}/pr-337-cmake-update.patch
+    PREFIX zlib
+    PATCH_COMMAND git apply ${PROJECT_SOURCE_DIR}/build_shared_libs.patch
     CMAKE_ARGS "${CMAKE_ARGS}"
     )
-

third_party/zlib/build_shared_libs.patch

@@ -0,0 +1,89 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 0fe939d..1873459 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -123,7 +123,7 @@ set(ZLIB_SRCS
+     zutil.c
+ )
+
+-if(NOT MINGW)
++if(BUILD_SHARED_LIBS AND NOT MINGW)
+     set(ZLIB_DLL_SRCS
+         win32/zlib1.rc # If present will override custom build rule below.
+     )
+@@ -167,7 +167,7 @@ file(READ ${CMAKE_CURRENT_SOURCE_DIR}/zlib.h _zlib_h_contents)
+ string(REGEX REPLACE ".*#define[ \t]+ZLIB_VERSION[ \t]+\"([-0-9A-Za-z.]+)\".*"
+     "\\1" ZLIB_FULL_VERSION ${_zlib_h_contents})
+
+-if(MINGW)
++if(BUILD_SHARED_LIBS AND MINGW)
+     # This gets us DLL resource information when compiling on MinGW.
+     if(NOT CMAKE_RC_COMPILER)
+         set(CMAKE_RC_COMPILER windres.exe)
+@@ -181,37 +181,42 @@ if(MINGW)
+                             -o ${CMAKE_CURRENT_BINARY_DIR}/zlib1rc.obj
+                             -i ${CMAKE_CURRENT_SOURCE_DIR}/win32/zlib1.rc)
+     set(ZLIB_DLL_SRCS ${CMAKE_CURRENT_BINARY_DIR}/zlib1rc.obj)
+-endif(MINGW)
+-
+-add_library(zlib SHARED ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_DLL_SRCS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
+-add_library(zlibstatic STATIC ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
+-set_target_properties(zlib PROPERTIES DEFINE_SYMBOL ZLIB_DLL)
+-set_target_properties(zlib PROPERTIES SOVERSION 1)
+-
+-if(NOT CYGWIN)
+-    # This property causes shared libraries on Linux to have the full version
+-    # encoded into their final filename.  We disable this on Cygwin because
+-    # it causes cygz-${ZLIB_FULL_VERSION}.dll to be created when cygz.dll
+-    # seems to be the default.
+-    #
+-    # This has no effect with MSVC, on that platform the version info for
+-    # the DLL comes from the resource file win32/zlib1.rc
+-    set_target_properties(zlib PROPERTIES VERSION ${ZLIB_FULL_VERSION})
+ endif()
+
++add_library(zlib ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_DLL_SRCS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
++
+ if(UNIX)
+     # On unix-like platforms the library is almost always called libz
+-   set_target_properties(zlib zlibstatic PROPERTIES OUTPUT_NAME z)
+-   if(NOT APPLE)
+-     set_target_properties(zlib PROPERTIES LINK_FLAGS "-Wl,--version-script,\"${CMAKE_CURRENT_SOURCE_DIR}/zlib.map\"")
+-   endif()
+-elseif(BUILD_SHARED_LIBS AND WIN32)
+-    # Creates zlib1.dll when building shared library version
+-    set_target_properties(zlib PROPERTIES SUFFIX "1.dll")
++   set_target_properties(zlib PROPERTIES OUTPUT_NAME z)
++endif()
++
++if(BUILD_SHARED_LIBS)
++    set_target_properties(zlib PROPERTIES DEFINE_SYMBOL ZLIB_DLL)
++    set_target_properties(zlib PROPERTIES SOVERSION 1)
++
++    if(NOT CYGWIN)
++        # This property causes shared libraries on Linux to have the full version
++        # encoded into their final filename.  We disable this on Cygwin because
++        # it causes cygz-${ZLIB_FULL_VERSION}.dll to be created when cygz.dll
++        # seems to be the default.
++        #
++        # This has no effect with MSVC, on that platform the version info for
++        # the DLL comes from the resource file win32/zlib1.rc
++        set_target_properties(zlib PROPERTIES VERSION ${ZLIB_FULL_VERSION})
++    endif()
++
++    if(UNIX AND NOT APPLE)
++        set_target_properties(zlib PROPERTIES LINK_FLAGS "-Wl,--version-script,\"${CMAKE_CURRENT_SOURCE_DIR}/zlib.map\"")
++    endif()
++
++    if(WIN32)
++        # Creates zlib1.dll when building shared library version
++        set_target_properties(zlib PROPERTIES SUFFIX "1.dll")
++    endif()
+ endif()
+
+ if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+-    install(TARGETS zlib zlibstatic
++    install(TARGETS zlib
+         RUNTIME DESTINATION "${INSTALL_BIN_DIR}"
+         ARCHIVE DESTINATION "${INSTALL_LIB_DIR}"
+         LIBRARY DESTINATION "${INSTALL_LIB_DIR}" )