3 files changed, 39 insertions, 8 deletions

diff --git a/src/common/bit_field.h b/src/common/bit_field.h
index dfd00d198..b6f0179c6 100644
--- a/src/common/bit_field.h
+++ b/src/common/bit_field.h
@@ -124,14 +124,35 @@ public:
     // so that we can use this within unions
     BitField() = default;
 
+#ifndef _WIN32
+    // We explicitly delete the copy assigment operator here, because the
+    // default copy assignment would copy the full storage value, rather than
+    // just the bits relevant to this particular bit field.
+    // Ideally, we would just implement the copy assignment to copy only the
+    // relevant bits, but this requires compiler support for unrestricted
+    // unions.
+    // MSVC 2013 has no support for this, hence we disable this code on
+    // Windows (so that the default copy assignment operator will be used).
+    // For any C++11 conformant compiler we delete the operator to make sure
+    // we never use this inappropriate operator to begin with.
+    // TODO: Implement this operator properly once all target compilers
+    // support unrestricted unions.
+    BitField& operator=(const BitField&) = delete;
+#endif
+
     __forceinline BitField& operator=(T val)
     {
-        storage = (storage & ~GetMask()) | ((val << position) & GetMask());
+        storage = (storage & ~GetMask()) | (((StorageType)val << position) & GetMask());
         return *this;
     }
 
     __forceinline operator T() const
     {
+        return Value();
+    }
+
+    __forceinline T Value() const
+    {
         if (std::numeric_limits<T>::is_signed)
         {
             std::size_t shift = 8 * sizeof(T)-bits;
@@ -168,5 +189,6 @@ private:
     static_assert(position < 8 * sizeof(T), "Invalid position");
     static_assert(bits <= 8 * sizeof(T), "Invalid number of bits");
     static_assert(bits > 0, "Invalid number of bits");
+    static_assert(std::is_standard_layout<T>::value, "Invalid base type");
 };
 #pragma pack()
diff --git a/src/common/register_set.h b/src/common/register_set.h
index 0418551b3..ba19a2614 100644
--- a/src/common/register_set.h
+++ b/src/common/register_set.h
@@ -34,7 +34,7 @@
 /*
  * Standardized way to define a group of registers and corresponding data structures. To define
  * a new register set, first define struct containing an enumeration called "Id" containing
- * all register IDs and a template union called "Struct". Specialize the Struct union for any
+ * all register IDs and a template struct called "Struct". Specialize the Struct struct for any
  * register ID which needs to be accessed in a specialized way. You can then declare the object
  * containing all register values using the RegisterSet<BaseType, DefiningStruct> type, where
  * BaseType is the underlying type of each register (e.g. u32).
@@ -54,7 +54,7 @@
  *
  *         // declare register definition structures
  *         template<Id id>
- *         union Struct;
+ *         struct Struct;
  *     };
  *
  *     // Define register set object
@@ -62,9 +62,11 @@
  *
  *     // define register definition structures
  *     template<>
- *     union Regs::Struct<Regs::Value1> {
- *         BitField<0, 4, u32> some_field;
- *         BitField<4, 3, u32> some_other_field;
+ *     struct Regs::Struct<Regs::Value1> {
+ *         union {
+ *             BitField<0, 4, u32> some_field;
+ *             BitField<4, 3, u32> some_other_field;
+ *         };
  *     };
  *
  * Usage in external code (within SomeNamespace scope):
@@ -77,7 +79,7 @@
  *
  *
  * @tparam BaseType Base type used for storing individual registers, e.g. u32
- * @tparam RegDefinition Class defining an enumeration called "Id" and a template<Id id> union, as described above.
+ * @tparam RegDefinition Class defining an enumeration called "Id" and a template<Id id> struct, as described above.
  * @note RegDefinition::Id needs to have an enum value called NumIds defining the number of registers to be allocated.
  */
 template<typename BaseType, typename RegDefinition>
diff --git a/src/common/scm_rev_gen.js b/src/common/scm_rev_gen.js
index 29c913b85..98313e376 100644
--- a/src/common/scm_rev_gen.js
+++ b/src/common/scm_rev_gen.js
@@ -6,8 +6,15 @@ var cmd_revision    = " rev-parse HEAD";
 var cmd_describe    = " describe --always --long --dirty";
 var cmd_branch      = " rev-parse --abbrev-ref HEAD";
 
+var git_search_paths = {
+    "git.cmd": 1,
+    "git": 1,
+    "C:\\Program Files (x86)\\Git\\bin\\git.exe": 1,
+    "C:\\Program Files\\Git\\bin\\git.exe": 1
+};
+
 function GetGitExe() {
-    for (var gitexe in { "git.cmd": 1, "git": 1 }) {
+    for (var gitexe in git_search_paths) {
         try {
             wshShell.Exec(gitexe);
             return gitexe;