[PGO] Simplify computehash interface (NFC)

[oota-llvm.git] / include / llvm / Support / AlignOf.h

diff --git a/include/llvm/Support/AlignOf.h b/include/llvm/Support/AlignOf.h
index 061d5acf2322b570ad197b753db150d10c2f1b4b..07da02d063c7d863b7848c83a5e9ca93398aa9cc 100644 (file)
--- a/include/llvm/Support/AlignOf.h
+++ b/include/llvm/Support/AlignOf.h
@@ -22,6 +22,14 @@ namespace llvm {
 template <typename T>
 struct AlignmentCalcImpl {
   char x;
+#if defined(_MSC_VER)
+// Disables "structure was padded due to __declspec(align())" warnings that are
+// generated by any class using AlignOf<T> with a manually specified alignment.
+// Although the warning is disabled in the LLVM project we need this pragma
+// as AlignOf.h is a published support header that's available for use
+// out-of-tree, and we would like that to compile cleanly at /W4.
+#pragma warning(suppress : 4324)
+#endif
   T t;
 private:
   AlignmentCalcImpl() {} // Never instantiate.
@@ -36,9 +44,18 @@ private:
 ///  compile-time constant (e.g., for template instantiation).
 template <typename T>
 struct AlignOf {
+#ifndef _MSC_VER
+  // Avoid warnings from GCC like:
+  //   comparison between 'enum llvm::AlignOf<X>::<anonymous>' and 'enum
+  //   llvm::AlignOf<Y>::<anonymous>' [-Wenum-compare]
+  // by using constexpr instead of enum.
+  // (except on MSVC, since it doesn't support constexpr yet).
+  static constexpr unsigned Alignment =
+      static_cast<unsigned int>(sizeof(AlignmentCalcImpl<T>) - sizeof(T));
+#else
   enum { Alignment =
          static_cast<unsigned int>(sizeof(AlignmentCalcImpl<T>) - sizeof(T)) };
-
+#endif
   enum { Alignment_GreaterEqual_2Bytes = Alignment >= 2 ? 1 : 0 };
   enum { Alignment_GreaterEqual_4Bytes = Alignment >= 4 ? 1 : 0 };
   enum { Alignment_GreaterEqual_8Bytes = Alignment >= 8 ? 1 : 0 };
@@ -50,6 +67,10 @@ struct AlignOf {
   enum { Alignment_LessEqual_16Bytes = Alignment <= 16 ? 1 : 0 };
 };
 
+#ifndef _MSC_VER
+template <typename T> constexpr unsigned AlignOf<T>::Alignment;
+#endif
+
 /// alignOf - A templated function that returns the minimum alignment of
 ///  of a type.  This provides no extra functionality beyond the AlignOf
 ///  class besides some cosmetic cleanliness.  Example usage:
@@ -190,12 +211,12 @@ union SizerImpl {
 } // end namespace detail
 
 /// \brief This union template exposes a suitably aligned and sized character
-/// array member which can hold elements of any of up to four types.
+/// array member which can hold elements of any of up to ten types.
 ///
 /// These types may be arrays, structs, or any other types. The goal is to
 /// expose a char array buffer member which can be used as suitable storage for
-/// a placement new of any of these types. Support for more than seven types can
-/// be added at the cost of more boiler plate.
+/// a placement new of any of these types. Support for more than ten types can
+/// be added at the cost of more boilerplate.
 template <typename T1,
           typename T2 = char, typename T3 = char, typename T4 = char,
           typename T5 = char, typename T6 = char, typename T7 = char,