Add Mac type conversion functions to QtCore

New API:
    static QString QString::fromCFString(CFStringRef string);
    CFStringRef QString::toCFString() const;
    static QString QString::fromNSString(const NSString *string);
    NSString *QString::toNSString() const;

    static QUrl QUrl::fromCFURL(CFURLRef url);
    CFURLRef QUrl::toCFURL() const;
    static QUrl QUrl::fromNSURL(const NSURL *url);
    NSURL * QUrl::toNSURL() const;

Add Q_OS_MAC-protected function declarations to header
files, add implementation to _mm files.

CF and NS types are forward-declared in the header
files to avoid including the CoreFoundation and Foundation
headers. This prevents accidental use of native types
in application code. Add helper macros for forward-
declaration to qglobal.h

Add cf_returns_retained/ns_returns_autoreleased attributes
to toCFString() and toNSURL(). These attributes assists
the clang static analyzer. Add Q_DECL_ helper macros
to qcompilerdetection.h.

Add test functions (in _mac.mm files) to the QString
and QUrl tests. Split out the test class declarations
into a separate headers files.

Change-Id: I60fd5e93f042316196284c3db0595835fe8c4ad4
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

3 files changed, 54 insertions, 0 deletions

diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 5306e432fd..a388bdb96f 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -620,6 +620,14 @@
 #  endif
 #endif // Q_CC_CLANG
 
+#if defined(Q_CC_CLANG) && defined(__APPLE__)
+/* Apple/clang specific features */
+#  define Q_DECL_CF_RETURNS_RETAINED __attribute__((cf_returns_retained))
+#  ifdef __OBJC__
+#    define Q_DECL_NS_RETURNS_AUTORELEASED __attribute__((ns_returns_autoreleased))
+#  endif
+#endif
+
 #if defined(Q_CC_GNU) && !defined(Q_CC_INTEL) && !defined(Q_CC_CLANG)
 #  if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
 #    if (__GNUC__ * 100 + __GNUC_MINOR__) >= 403
@@ -849,6 +857,12 @@
 #    define Q_FUNC_INFO __FILE__ ":" QT_STRINGIFY(__LINE__)
 #  endif
 #endif
+#ifndef Q_DECL_CF_RETURNS_RETAINED
+#  define Q_DECL_CF_RETURNS_RETAINED
+#endif
+#ifndef Q_DECL_NS_RETURNS_AUTORELEASED
+#  define Q_DECL_NS_RETURNS_AUTORELEASED
+#endif
 
 /*
    Workaround for static const members on MSVC++.
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index ce87e4bfd9..59bdecc868 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -3361,4 +3361,36 @@ bool QInternal::activateCallbacks(Callback cb, void **parameters)
     \sa Q_DECL_OVERRIDE
 */
 
+/*!
+    \macro Q_FORWARD_DECLARE_OBJC_CLASS(classname)
+    \since 5.2
+    \relates <QtGlobal>
+
+    Forward-declares an Objective-C \a classname in a manner such that it can be
+    compiled as either Objective-C or C++.
+
+    This is primarily intended for use in header files that may be included by
+    both Objective-C and C++ source files.
+*/
+
+/*!
+    \macro Q_FORWARD_DECLARE_CF_TYPE(type)
+    \since 5.2
+    \relates <QtGlobal>
+
+    Forward-declares a Core Foundation \a type. This includes the actual
+    type and the ref type. For example, Q_FORWARD_DECLARE_CF_TYPE(CFString)
+    declares __CFString and CFStringRef.
+*/
+
+/*!
+    \macro Q_FORWARD_DECLARE_MUTABLE_CF_TYPE(type)
+    \since 5.2
+    \relates <QtGlobal>
+
+    Forward-declares a mutable Core Foundation \a type. This includes the actual
+    type and the ref type. For example, Q_FORWARD_DECLARE_CF_TYPE(CFString)
+    declares __CFMutableString and CFMutableStringRef.
+*/
+
 QT_END_NAMESPACE
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h
index f38672bdc1..b4830bda1f 100644
--- a/src/corelib/global/qglobal.h
+++ b/src/corelib/global/qglobal.h
@@ -993,6 +993,14 @@ template <bool B, typename T = void> struct QEnableIf;
 template <typename T> struct QEnableIf<true, T> { typedef T Type; };
 }
 
+#ifdef __OBJC__
+#define Q_FORWARD_DECLARE_OBJC_CLASS(classname) @class classname
+#else
+#define Q_FORWARD_DECLARE_OBJC_CLASS(classname) typedef struct objc_object classname
+#endif
+#define Q_FORWARD_DECLARE_CF_TYPE(type) typedef const struct __ ## type * type ## Ref
+#define Q_FORWARD_DECLARE_MUTABLE_CF_TYPE(type) typedef struct __ ## type * type ## Ref
+
 QT_END_NAMESPACE
 // Q_GLOBAL_STATIC
 #include <QtCore/qglobalstatic.h>