1 files changed, 60 insertions, 23 deletions
diff --git a/JavaScriptCore/wtf/StdLibExtras.h b/JavaScriptCore/wtf/StdLibExtras.h
index 9dfb969..4bb0076 100644
--- a/JavaScriptCore/wtf/StdLibExtras.h
+++ b/JavaScriptCore/wtf/StdLibExtras.h
@@ -26,7 +26,6 @@
 #ifndef WTF_StdLibExtras_h
 #define WTF_StdLibExtras_h
 
-#include <wtf/Platform.h>
 #include <wtf/Assertions.h>
 
 // Use these to declare and define a static local variable (static T;) so that
@@ -52,31 +51,69 @@
 #define STRINGIZE(exp) #exp
 #define STRINGIZE_VALUE_OF(exp) STRINGIZE(exp)
 
+/*
+ * The reinterpret_cast<Type1*>([pointer to Type2]) expressions - where
+ * sizeof(Type1) > sizeof(Type2) - cause the following warning on ARM with GCC:
+ * increases required alignment of target type.
+ *
+ * An implicit or an extra static_cast<void*> bypasses the warning.
+ * For more info see the following bugzilla entries:
+ * - https://bugs.webkit.org/show_bug.cgi?id=38045
+ * - http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43976
+ */
+#if (CPU(ARM) || CPU(MIPS)) && COMPILER(GCC)
+template<typename Type>
+bool isPointerTypeAlignmentOkay(Type* ptr)
+{
+    return !(reinterpret_cast<intptr_t>(ptr) % __alignof__(Type));
+}
+
+template<typename TypePtr>
+TypePtr reinterpret_cast_ptr(void* ptr)
+{
+    ASSERT(isPointerTypeAlignmentOkay(reinterpret_cast<TypePtr>(ptr)));
+    return reinterpret_cast<TypePtr>(ptr);
+}
+
+template<typename TypePtr>
+TypePtr reinterpret_cast_ptr(const void* ptr)
+{
+    ASSERT(isPointerTypeAlignmentOkay(reinterpret_cast<TypePtr>(ptr)));
+    return reinterpret_cast<TypePtr>(ptr);
+}
+#else
+#define reinterpret_cast_ptr reinterpret_cast
+#endif
+
 namespace WTF {
 
-    /*
-     * C++'s idea of a reinterpret_cast lacks sufficient cojones.
-     */
-    template<typename TO, typename FROM>
-    TO bitwise_cast(FROM from)
-    {
-        COMPILE_ASSERT(sizeof(TO) == sizeof(FROM), WTF_bitwise_cast_sizeof_casted_types_is_equal);
-        union {
-            FROM from;
-            TO to;
-        } u;
-        u.from = from;
-        return u.to;
-    }
+/*
+ * C++'s idea of a reinterpret_cast lacks sufficient cojones.
+ */
+template<typename TO, typename FROM>
+inline TO bitwise_cast(FROM from)
+{
+    COMPILE_ASSERT(sizeof(TO) == sizeof(FROM), WTF_bitwise_cast_sizeof_casted_types_is_equal);
+    union {
+        FROM from;
+        TO to;
+    } u;
+    u.from = from;
+    return u.to;
+}
+
+// Returns a count of the number of bits set in 'bits'.
+inline size_t bitCount(unsigned bits)
+{
+    bits = bits - ((bits >> 1) & 0x55555555);
+    bits = (bits & 0x33333333) + ((bits >> 2) & 0x33333333);
+    return (((bits + (bits >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
+}
 
-    // Returns a count of the number of bits set in 'bits'.
-    inline size_t bitCount(unsigned bits)
-    {
-        bits = bits - ((bits >> 1) & 0x55555555);
-        bits = (bits & 0x33333333) + ((bits >> 2) & 0x33333333);
-        return (((bits + (bits >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
-    }
+// Macro that returns a compile time constant with the length of an array, but gives an error if passed a non-array.
+template<typename T, size_t Size> char (&ArrayLengthHelperFunction(T (&)[Size]))[Size];
+#define WTF_ARRAY_LENGTH(array) sizeof(::WTF::ArrayLengthHelperFunction(array))
 
 } // namespace WTF
 
-#endif
+#endif // WTF_StdLibExtras_h