global.pri: better warnings settings for clang <=9

global.pri

@@ -51,14 +51,18 @@ run-without-python {
 # QMAKE_LFLAGS_RELEASE_WITH_DEBUGINFO
 
     QMAKE_CFLAGS_WARN_ON += -Wall -Wextra -Wmissing-prototypes -Wmissing-declarations -Wno-multichar -Winit-self -Wno-long-long
-    QMAKE_CXXFLAGS_WARN_ON += -Wall -Wextra -Wno-multichar -Winit-self -Wno-long-long -Wno-deprecated-copy
+    QMAKE_CXXFLAGS_WARN_ON += -Wall -Wextra -Wno-multichar -Winit-self -Wno-long-long
     *clang* | *xcode* {
     	# In file included from <built-in>:1:
     	# In file included from /usr/local/Cellar/python@2/2.7.16/Frameworks/Python.framework/Versions/2.7/include/python2.7/Python.h:88:
     	# /usr/local/Cellar/python@2/2.7.16/Frameworks/Python.framework/Versions/2.7/include/python2.7/unicodeobject.h:534:5: warning: 'register' storage class specifier is deprecated and incompatible with C++17 [-Wdeprecated-register]
     	#     register PyObject *obj,     /* Object */
     	#     ^~~~~~~~~
         QMAKE_CXXFLAGS += -Wno-deprecated-register
+        # Silence clang-10 warnings about deprecated copy (there are too many of these)
+        QMAKE_CXXFLAGS += -Wno-deprecated-copy
+        # Do not warn about unknown warnings (including the one just above on clang <=9)
+        QMAKE_CXXFLAGS += -Wno-unknown-warning-option
     }
     #QMAKE_CFLAGS_WARN_ON += -pedantic
     #QMAKE_CXXFLAGS_WARN_ON += -pedantic