67 lines
2.7 KiB
Diff
67 lines
2.7 KiB
Diff
# reason: FTBFS with gcc9
|
|
# src: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925811
|
|
|
|
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
|
|
|