Build Qt (and client apps using it) with /permissive-

*Not* using /permissive- exposes Qt and client apps to interesting bugs and/or build failures, (e.g. QTBUG-87225, or 19b5520). We demand strict conformance by any other compiler, it's time to demand it from MSVC too. The Windows headers themselves are clean starting from the Windows Fall Creators SDK (10.0.16299.0), and moreover Qt 6 will drop WinRT; therefore, the comment in the mkspecs does not apply any more. Since /permissive- implies /Zc:referenceBinding, drop that option. The other implied options are set on MSVC < 2017, but I leave them in to avoid tinkering with the fragile lists of C/C++ flags. Rename the CMake internal helper function to better describe what it does. Fixes: QTBUG-85633 Fixes: QTBUG-85637 Fixes: QTBUG-85635 Fixes: QTBUG-88244 Change-Id: Ie03fddb61aa066fdc14b7231c22e7108b4a02fbb Reviewed-by: Friedemann Kleint <[email protected]> Reviewed-by: Kai Koehne <[email protected]> Reviewed-by: Volker Hilsheimer <[email protected]>
fwcd · Nov 10, 2020 · 8780fbb · 8780fbb
1 parent ef051a6
commit 8780fbb
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Showing 5 changed files with 6 additions and 11 deletions.
diff --git a/cmake/QtFlagHandlingHelpers.cmake b/cmake/QtFlagHandlingHelpers.cmake
@@ -228,11 +228,11 @@ function(qt_set_language_standards_interface_compile_features target)
     target_compile_features("${target}" INTERFACE ${cpp_feature})
 endfunction()
 
-function(qt_enable_msvc_cplusplus_define target visibility)
+function(qt_set_msvc_cplusplus_options target visibility)
     # For MSVC we need to explicitly pass -Zc:__cplusplus to get correct __cplusplus.
     # Check qt_config_compile_test for more info.
     if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" AND MSVC_VERSION GREATER_EQUAL 1913)
-        target_compile_options("${target}" ${visibility} "-Zc:__cplusplus")
+        target_compile_options("${target}" ${visibility} "-Zc:__cplusplus" "-permissive-")
     endif()
 endfunction()
 

diff --git a/cmake/QtPublicTargetsHelpers.cmake b/cmake/QtPublicTargetsHelpers.cmake
@@ -20,7 +20,7 @@ function(qt_internal_setup_public_platform_target)
         target_link_libraries(Platform INTERFACE log)
     endif()
 
-    qt_enable_msvc_cplusplus_define(Platform INTERFACE)
+    qt_set_msvc_cplusplus_options(Platform INTERFACE)
 
     # Propagate minimum C++ 17 via Platform to Qt consumers (apps), after the global features
     # are computed.

diff --git a/mkspecs/common/msvc-version.conf b/mkspecs/common/msvc-version.conf
@@ -78,7 +78,7 @@ greaterThan(QMAKE_MSC_VER, 1909) {
     # Visual Studio 2017 (15.0) / Visual C++ 19.10 and up
     MSVC_VER            = 15.0
     COMPAT_MKSPEC       = win32-msvc2017
-    QMAKE_CXXFLAGS     += -Zc:referenceBinding
+    QMAKE_CXXFLAGS     += -permissive-
 
     # Only Visual Studio 2017 version 15.3 / Visual C++ 19.11 & up have support
     # for AVX-512. We enable the switches anyway and let configure check if they
@@ -93,11 +93,6 @@ greaterThan(QMAKE_MSC_VER, 1909) {
     QMAKE_CFLAGS_AVX512IFMA = -arch:AVX512
     QMAKE_CFLAGS_AVX512VBMI = -arch:AVX512
 
-    # For now permissive fails as soon as UWP API comes into play. In qtbase this
-    # API is used in direct2d, but also in multimedia, positioning and sensors.
-    # We can try again with a later version of Visual Studio.
-    # QMAKE_CXXFLAGS_STRICTCXX = -permissive-
-
     # MSVC partially supports the following, but '__cplusplus' definition is set
     # as for C++98 until MSVC fully conforms with C++14, see
     # https://developercommunity.visualstudio.com/content/problem/139261/msvc-incorrectly-defines-cplusplus.html

diff --git a/qmake/CMakeLists.txt b/qmake/CMakeLists.txt
@@ -275,7 +275,7 @@ set_target_properties(${target_name} PROPERTIES
 
 qt_internal_apply_gc_binaries(${target_name} PRIVATE) # special case
 
-qt_enable_msvc_cplusplus_define(${target_name} PUBLIC) # special case
+qt_set_msvc_cplusplus_options(${target_name} PUBLIC) # special case
 qt_skip_warnings_are_errors(${target_name}) # special case
 qt_internal_apply_intel_cet(Bootstrap PUBLIC) # special case
 

diff --git a/src/tools/bootstrap/CMakeLists.txt b/src/tools/bootstrap/CMakeLists.txt
@@ -265,6 +265,6 @@ target_link_libraries(Bootstrap PRIVATE PlatformCommonInternal)
 qt_internal_apply_gc_binaries(Bootstrap PUBLIC)
 set_target_properties(Bootstrap PROPERTIES AUTOMOC OFF AUTOUIC OFF AUTORCC OFF)
 qt_internal_add_target_aliases(Bootstrap)
-qt_enable_msvc_cplusplus_define(Bootstrap PUBLIC)
+qt_set_msvc_cplusplus_options(Bootstrap PUBLIC)
 qt_internal_apply_intel_cet(Bootstrap PUBLIC)
 # special case end