fix bug for static init
Ugh! Static initialization of instance variables is a very bad idea.
This fix is taken from the Chromium code-base. It includes their
double-fix for ARM.
* https://codereview.chromium.org/24984004
* https://src.chromium.org/viewvc/chrome?revision=226099&view=revision
* https://code.google.com/p/webrtc/issues/detail?id=1777
diff --git a/include/json/value.h b/include/json/value.h
index 92526a4..1ad006f 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -133,7 +133,7 @@
typedef Json::LargestUInt LargestUInt;
typedef Json::ArrayIndex ArrayIndex;
- static const Value null;
+ static const Value& null;
/// Minimum signed integer value that can be stored in a Json::Value.
static const LargestInt minLargestInt;
/// Maximum signed integer value that can be stored in a Json::Value.
diff --git a/src/lib_json/json_value.cpp b/src/lib_json/json_value.cpp
index 29380e1..5e78065 100644
--- a/src/lib_json/json_value.cpp
+++ b/src/lib_json/json_value.cpp
@@ -25,7 +25,17 @@
namespace Json {
-const Value Value::null;
+// This is a walkaround to avoid the static initialization of Value::null.
+// kNull must be word-aligned to avoid crashing on ARM. We use an alignment of
+// 8 (instead of 4) as a bit of future-proofing.
+#if defined(__ARMEL__)
+#define ALIGNAS(byte_alignment) __attribute__((aligned(byte_alignment)))
+#else
+#define ALIGNAS(byte_alignment)
+#endif
+static const unsigned char ALIGNAS(8) kNull[sizeof(Value)] = {0};
+const Value& Value::null = reinterpret_cast<const Value&>(kNull);
+
const Int Value::minInt = Int(~(UInt(-1) / 2));
const Int Value::maxInt = Int(UInt(-1) / 2);
const UInt Value::maxUInt = UInt(-1);