qt: Qt 4 compatibility with gcc 9 and later

2 files changed, 65 insertions, 0 deletions

diff --git a/src/qt-3-gcc9.patch b/src/qt-3-gcc9.patch
new file mode 100644
index 0000000..ae54cdb
--- /dev/null
+++ b/src/qt-3-gcc9.patch
@@ -0,0 +1,64 @@
+From c35a3f519007af44c3b364b9af86f6a336f6411b Mon Sep 17 00:00:00 2001
+From: Thiago Macieira <thiago.macieira@intel.com>
+Date: Tue, 11 Feb 2014 16:17:46 -0800
+Subject: [PATCH] Redo the Q_FOREACH loop control without GCC statement
+ expressions
+
+It's possible to do without them, which probably makes the number of
+supported compilers a lot bigger: they just need to support decltype()
+or __typeof__.
+
+That includes the Intel compiler. The old code was also apparently
+working, but no one had realized the old workaround for some old version
+was still in place.
+
+The loop overhead is more or less the same. I have not done benchmarks,
+but inspection of the generated assembly shows more or less the same
+number of instructions.
+
+Change-Id: I32d499c84a6ddd19d994b49f17a469acb5c3a3f1
+Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
+Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
+
+Backported to Qt 4
+
+--- a/src/corelib/global/qglobal.h
++++ b/src/corelib/global/qglobal.h
+@@ -2482,22 +2482,32 @@ typedef uint Flags;
+ 
+ #endif /* Q_NO_TYPESAFE_FLAGS */
+ 
+-#if defined(Q_CC_GNU) && !defined(Q_CC_INTEL) && !defined(Q_CC_RVCT)
++#if (defined(Q_CC_GNU) && !defined(Q_CC_RVCT))
+ /* make use of typeof-extension */
+ template <typename T>
+ class QForeachContainer {
+ public:
+-    inline QForeachContainer(const T& t) : c(t), brk(0), i(c.begin()), e(c.end()) { }
++    inline QForeachContainer(const T& t) : c(t), i(c.begin()), e(c.end()), control(1) { }
+     const T c;
+     int brk;
+     typename T::const_iterator i, e;
++    int control;
+ };
+ 
++// Explanation of the control word:
++//  - it's initialized to 1
++//  - that means both the inner and outer loops start
++//  - if there were no breaks, at the end of the inner loop, it's set to 0, which
++//    causes it to exit (the inner loop is run exactly once)
++//  - at the end of the outer loop, it's inverted, so it becomes 1 again, allowing
++//    the outer loop to continue executing
++//  - if there was a break inside the inner loop, it will exit with control still
++//    set to 1; in that case, the outer loop will invert it to 0 and will exit too
+ #define Q_FOREACH(variable, container)                                \
+ for (QForeachContainer<__typeof__(container)> _container_(container); \
+-     !_container_.brk && _container_.i != _container_.e;              \
+-     __extension__  ({ ++_container_.brk; ++_container_.i; }))                       \
+-    for (variable = *_container_.i;; __extension__ ({--_container_.brk; break;}))
++     _container_.control && _container_.i != _container_.e;         \
++     ++_container_.i, _container_.control ^= 1)                     \
++    for (variable = *_container_.i; _container_.control; _container_.control = 0)
+ 
+ #else
+ 
diff --git a/src/qt.mk b/src/qt.mk
index 9bc512c..a8268ac 100644
--- a/src/qt.mk
+++ b/src/qt.mk
@@ -131,6 +131,7 @@ define $(PKG)_BUILD
     '$(PREFIX)/$(TARGET)/qt/bin/rcc' -name qt-test -o '$(1)/test-$(PKG)-pkgconfig/qrc_qt-test.cpp' '$(TOP_DIR)/src/qt-test.qrc'
     '$(TARGET)-g++' \
         -W -Wall -Werror -std=c++0x -pedantic \
+        -Wno-deprecated-copy \
         '$(TOP_DIR)/src/qt-test.cpp' \
         '$(1)/test-$(PKG)-pkgconfig/moc_qt-test.cpp' \
         '$(1)/test-$(PKG)-pkgconfig/qrc_qt-test.cpp' \