From 606924132ff1f11b9d7b4357251f07ccabb8bdb6 Mon Sep 17 00:00:00 2001 From: Lars Knoll Date: Thu, 18 Aug 2016 22:24:26 +0200 Subject: Add support for safe feature checking at compile time Added a qtConfig(feature) function to qmake, and a QT_CONFIG(feature) macro. These can safely check whether a certain compile time feature of Qt is enabled or not. For this to work the feature has to have a publicFeature or privateFeature output in the configure.json file. In pro files, please use the qtConfig(feature) test function instead of checking contains(QT_CONFIG, feature), as the latter will be unreliable with the upcoming modularization (it requires a load(qt_module_config) before doing any such checks). Note that feature names are now lowercase, and identical (except for hyphens versus underscores currently) in the pro and c++ files. This makes the logic easier to follow, as we avoid all double negations, and most importantly, QT_CONFIG and qtConfig are implemented in a way that you'll get a build error for a mistyped or non-existent feature. This will also prevent accidental use of a widget feature in gui in the future. This gives us complete symmetry between the handling in pro and c++ files. Change-Id: I60404f97953724e639ffb6386cce2e8b1e4b735a Reviewed-by: Lars Knoll Reviewed-by: Oswald Buddenhagen --- src/corelib/global/qglobal.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h index d9ffca3810..e6d65b0f99 100644 --- a/src/corelib/global/qglobal.h +++ b/src/corelib/global/qglobal.h @@ -62,13 +62,23 @@ #endif // The QT_SUPPORTS macro is deprecated. Don't use it in new code. -// Instead, use #ifdef/ndef QT_NO_feature. +// Instead, use QT_CONFIG(feature) // ### Qt6: remove macro #ifdef _MSC_VER # define QT_SUPPORTS(FEATURE) (!defined QT_NO_##FEATURE) #else # define QT_SUPPORTS(FEATURE) (!defined(QT_NO_##FEATURE)) #endif + +/* + The QT_CONFIG macro implements a safe compile time check for features of Qt. + Features can be in three states: + 0 or undefined: This will lead to a compile error when testing for it + -1: The feature is not available + 1: The feature is available +*/ +#define QT_CONFIG(feature) (1/QT_FEATURE_##feature == 1) + #if QT_VERSION >= QT_VERSION_CHECK(6,0,0) # define QT_NO_UNSHARABLE_CONTAINERS #endif -- cgit v1.2.3