cmake: Determine minimum deployment target for Qt

[quassel.git] / CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 80040cf..cebb61b 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -108,11 +108,6 @@ endif()
 
 # The following options are not for end-user consumption, so don't list them in the feature summary
 option(FATAL_WARNINGS "Make compile warnings fatal (most useful for CI builds)" OFF)
-option(WARN_QT_DEPRECATION "Warn about deprecated Qt functionality" OFF)
-if (WARN_QT_DEPRECATION)
-    # Enable Qt deprecation warnings for Qt < 5.13 (on by default in newer versions)
-    add_definitions("-DQT_DEPRECATED_WARNINGS")
-endif()
 cmake_dependent_option(DEPLOY "Add required libs to bundle resources and create a dmg" OFF "APPLE" OFF)
 
 # List of authenticators and the cmake flags to build them
@@ -155,14 +150,20 @@ endif()
 # Set up Qt
 #####################################################################
 
+set(QT_MIN_VERSION "5.5.0")
+
+# Enable Qt deprecation warnings for Qt < 5.13 (on by default in newer versions)
+add_definitions(-DQT_DEPRECATED_WARNINGS)
+
+# Disable all Qt APIs that were deprecated in 5.5 and before
+add_definitions(-DQT_DISABLE_DEPRECATED_BEFORE=0x050500)
+
 # Find package dependencies
 #
 # Note that you can forcefully disable optional packages
 # using -DCMAKE_DISABLE_FIND_PACKAGE_<PkgName>=TRUE
 #####################################################################
 
-set(QT_MIN_VERSION "5.5.0")
-
 # Required Qt components
 set(qt_components Core Network)
 if (BUILD_GUI)
@@ -179,6 +180,33 @@ set_package_properties(Qt5 PROPERTIES TYPE REQUIRED
 )
 message(STATUS "Found Qt ${Qt5Core_VERSION}")
 
+# Determine minimum deployment target for macOS supported by Qt
+if(APPLE)
+    if(NOT QMAKE_MACOSX_DEPLOYMENT_TARGET)
+        # qmake cannot be queried directly for QMAKE_MACOSX_DEPLOYMENT_TARGET (it is a mkspec, not a property).
+        # Instead, invoke qmake on an empty project file, which causes it to output the relevant keys and their values
+        # for subsequent parsing.
+        # A file named .qmake.stash is always created, so remove it (and empty.pro) afterwards.
+        set(qmakeEmptyProjectFile "${CMAKE_BINARY_DIR}/empty.pro")
+        set(qmakeStashFile "${CMAKE_BINARY_DIR}/.qmake.stash")
+        file(WRITE ${qmakeEmptyProjectFile} "")
+        get_target_property(QMAKE_EXECUTABLE Qt5::qmake IMPORTED_LOCATION)
+        execute_process(
+            COMMAND ${QMAKE_EXECUTABLE} -E ${qmakeEmptyProjectFile}
+            WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+            OUTPUT_VARIABLE qmakeOutput
+        )
+        file(REMOVE ${qmakeEmptyProjectFile} ${qmakeStashFile})
+        string(REGEX MATCH "QMAKE_MACOSX_DEPLOYMENT_TARGET[ ]*=[ ]*([0-9.]+)" foo ${qmakeOutput})
+        if(NOT CMAKE_MATCH_1)
+            message(FATAL_ERROR "Could not determine the deployment target for Qt")
+        endif()
+        set(QMAKE_MACOSX_DEPLOYMENT_TARGET ${CMAKE_MATCH_1} CACHE INTERNAL "")
+        mark_as_advanced(QMAKE_MACOSX_DEPLOYMENT_TARGET)
+    endif()
+    message(STATUS "Minimum macOS version supported by Qt: ${QMAKE_MACOSX_DEPLOYMENT_TARGET}")
+endif()
+
 # Check for SSL support in Qt
 cmake_push_check_state(RESET)
 set(CMAKE_REQUIRED_LIBRARIES Qt5::Core)