diff --git a/llvm/include/llvm/ADT/PointerIntPair.h b/llvm/include/llvm/ADT/PointerIntPair.h
index 0299a83c4411..0cfd470003af 100644
--- a/llvm/include/llvm/ADT/PointerIntPair.h
+++ b/llvm/include/llvm/ADT/PointerIntPair.h
@@ -14,6 +14,7 @@
 #ifndef LLVM_ADT_POINTERINTPAIR_H
 #define LLVM_ADT_POINTERINTPAIR_H
 
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
 #include <cassert>
 
@@ -40,7 +41,7 @@ template <typename PointerTy, unsigned IntBits, typename IntType=unsigned,
           typename PtrTraits = PointerLikeTypeTraits<PointerTy> >
 class PointerIntPair {
   intptr_t Value;
-  enum {
+  enum LLVM_ENUM_INT_TYPE(uintptr_t) {
     /// PointerBitMask - The bits that come from the pointer.
     PointerBitMask =
       ~(uintptr_t)(((intptr_t)1 << PtrTraits::NumLowBitsAvailable)-1),
diff --git a/llvm/include/llvm/IR/Attributes.h b/llvm/include/llvm/IR/Attributes.h
index ebee637004b6..c23ba0f73c58 100644
--- a/llvm/include/llvm/IR/Attributes.h
+++ b/llvm/include/llvm/IR/Attributes.h
@@ -18,6 +18,7 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/FoldingSet.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
 #include <bitset>
 #include <cassert>
@@ -200,7 +201,7 @@ public:
 /// index `1'.
 class AttributeSet {
 public:
-  enum AttrIndex {
+  enum AttrIndex LLVM_ENUM_INT_TYPE(unsigned) {
     ReturnIndex = 0U,
     FunctionIndex = ~0U
   };
diff --git a/llvm/include/llvm/IR/InlineAsm.h b/llvm/include/llvm/IR/InlineAsm.h
index 33e4ab8522d1..3398a83e365e 100644
--- a/llvm/include/llvm/IR/InlineAsm.h
+++ b/llvm/include/llvm/IR/InlineAsm.h
@@ -197,7 +197,7 @@ public:
   // These are helper methods for dealing with flags in the INLINEASM SDNode
   // in the backend.
   
-  enum {
+  enum LLVM_ENUM_INT_TYPE(uint32_t) {
     // Fixed operands on an INLINEASM SDNode.
     Op_InputChain = 0,
     Op_AsmString = 1,
diff --git a/llvm/include/llvm/MC/MCSectionMachO.h b/llvm/include/llvm/MC/MCSectionMachO.h
index b68bd8596801..d7e88ea56124 100644
--- a/llvm/include/llvm/MC/MCSectionMachO.h
+++ b/llvm/include/llvm/MC/MCSectionMachO.h
@@ -41,7 +41,7 @@ public:
 
   /// These are the section type and attributes fields.  A MachO section can
   /// have only one Type, but can have any of the attributes specified.
-  enum {
+  enum LLVM_ENUM_INT_TYPE(uint32_t) {
     // TypeAndAttributes bitmasks.
     SECTION_TYPE       = 0x000000FFU,
     SECTION_ATTRIBUTES = 0xFFFFFF00U,
diff --git a/llvm/include/llvm/MC/MachineLocation.h b/llvm/include/llvm/MC/MachineLocation.h
index 7d9abc3587df..b3fbee77021d 100644
--- a/llvm/include/llvm/MC/MachineLocation.h
+++ b/llvm/include/llvm/MC/MachineLocation.h
@@ -16,6 +16,9 @@
 #ifndef LLVM_MC_MACHINELOCATION_H
 #define LLVM_MC_MACHINELOCATION_H
 
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DataTypes.h"
+
 namespace llvm {
   class MCSymbol;
 
@@ -25,7 +28,7 @@ private:
   unsigned Register;                    // gcc/gdb register number.
   int Offset;                           // Displacement if not register.
 public:
-  enum {
+  enum LLVM_ENUM_INT_TYPE(uint32_t) {
     // The target register number for an abstract frame pointer. The value is
     // an arbitrary value that doesn't collide with any real target register.
     VirtualFP = ~0U
diff --git a/llvm/include/llvm/Object/ObjectFile.h b/llvm/include/llvm/Object/ObjectFile.h
index f434d63736f6..6973c6713b52 100644
--- a/llvm/include/llvm/Object/ObjectFile.h
+++ b/llvm/include/llvm/Object/ObjectFile.h
@@ -192,7 +192,7 @@ public:
     ST_Other
   };
 
-  enum Flags {
+  enum Flags LLVM_ENUM_INT_TYPE(unsigned) {
     SF_None            = 0,
     SF_Undefined       = 1U << 0,  // Symbol is defined in another object file
     SF_Global          = 1U << 1,  // Global symbol
diff --git a/llvm/include/llvm/Support/COFF.h b/llvm/include/llvm/Support/COFF.h
index 541d563cef49..9cc3989df043 100644
--- a/llvm/include/llvm/Support/COFF.h
+++ b/llvm/include/llvm/Support/COFF.h
@@ -222,7 +222,7 @@ namespace COFF {
     uint32_t Characteristics;
   };
 
-  enum SectionCharacteristics {
+  enum SectionCharacteristics LLVM_ENUM_INT_TYPE(uint32_t) {
     SC_Invalid = 0xffffffff,
 
     IMAGE_SCN_TYPE_NO_PAD            = 0x00000008,
diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h
index c32a48546ce2..13920fcc5a89 100644
--- a/llvm/include/llvm/Support/Compiler.h
+++ b/llvm/include/llvm/Support/Compiler.h
@@ -391,4 +391,16 @@
 # define LLVM_STATIC_ASSERT(expr, msg)
 #endif
 
+/// \macro LLVM_ENUM_INT_TYPE
+/// \brief Expands to colon followed by the given integral type on compilers
+/// which support C++11 strong enums.  This can be used to make enums unsigned
+/// with MSVC.
+#if __has_feature(cxx_strong_enums)
+# define LLVM_ENUM_INT_TYPE(intty) : intty
+#elif defined(_MSC_VER) && _MSC_VER >= 1600  // Added in MSVC 2010.
+# define LLVM_ENUM_INT_TYPE(intty) : intty
+#else
+# define LLVM_ENUM_INT_TYPE(intty)
+#endif
+
 #endif
diff --git a/llvm/include/llvm/Support/Dwarf.h b/llvm/include/llvm/Support/Dwarf.h
index 70c46db0e97b..0f3354143849 100644
--- a/llvm/include/llvm/Support/Dwarf.h
+++ b/llvm/include/llvm/Support/Dwarf.h
@@ -16,6 +16,7 @@
 #ifndef LLVM_SUPPORT_DWARF_H
 #define LLVM_SUPPORT_DWARF_H
 
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/DataTypes.h"
 
 namespace llvm {
@@ -23,7 +24,7 @@ namespace llvm {
 //===----------------------------------------------------------------------===//
 // Debug info constants.
 
-enum {
+enum LLVM_ENUM_INT_TYPE(uint32_t) {
   LLVMDebugVersion = (12 << 16),    // Current version of debug information.
   LLVMDebugVersion11 = (11 << 16),  // Constant for version 11.
   LLVMDebugVersion10 = (10 << 16),  // Constant for version 10.
@@ -46,7 +47,7 @@ namespace dwarf {
 // Do not mix the following two enumerations sets.  DW_TAG_invalid changes the
 // enumeration base type.
 
-enum LLVMConstants {
+enum LLVMConstants LLVM_ENUM_INT_TYPE(uint32_t) {
   // llvm mock tags
   DW_TAG_invalid = ~0U, // Tag for invalid results.
 
diff --git a/llvm/include/llvm/Support/ELF.h b/llvm/include/llvm/Support/ELF.h
index 8f92832795b7..61d1a0d5cbd9 100644
--- a/llvm/include/llvm/Support/ELF.h
+++ b/llvm/include/llvm/Support/ELF.h
@@ -650,7 +650,7 @@ enum {
 };
 
 // ARM Specific e_flags
-enum {
+enum LLVM_ENUM_INT_TYPE(unsigned) {
   EF_ARM_SOFT_FLOAT =     0x00000200U,
   EF_ARM_VFP_FLOAT =      0x00000400U,
   EF_ARM_EABI_UNKNOWN =   0x00000000U,
@@ -800,7 +800,7 @@ enum {
 };
 
 // Mips Specific e_flags
-enum {
+enum LLVM_ENUM_INT_TYPE(unsigned) {
   EF_MIPS_NOREORDER = 0x00000001, // Don't reorder instructions
   EF_MIPS_PIC       = 0x00000002, // Position independent code
   EF_MIPS_CPIC      = 0x00000004, // Call object with Position independent code
@@ -1116,7 +1116,7 @@ enum {
 };
 
 // Section types.
-enum {
+enum LLVM_ENUM_INT_TYPE(unsigned) {
   SHT_NULL          = 0,  // No associated section (inactive entry).
   SHT_PROGBITS      = 1,  // Program-defined contents.
   SHT_SYMTAB        = 2,  // Symbol table.
@@ -1164,7 +1164,7 @@ enum {
 };
 
 // Section flags.
-enum {
+enum LLVM_ENUM_INT_TYPE(unsigned) {
   // Section data should be writable during execution.
   SHF_WRITE = 0x1,
 
@@ -1234,7 +1234,7 @@ enum {
 };
 
 // Section Group Flags
-enum {
+enum LLVM_ENUM_INT_TYPE(unsigned) {
   GRP_COMDAT = 0x1,
   GRP_MASKOS = 0x0ff00000,
   GRP_MASKPROC = 0xf0000000
@@ -1451,7 +1451,7 @@ enum {
 };
 
 // Segment flag bits.
-enum {
+enum LLVM_ENUM_INT_TYPE(unsigned) {
   PF_X        = 1,         // Execute
   PF_W        = 2,         // Write
   PF_R        = 4,         // Read
diff --git a/llvm/include/llvm/Support/MachO.h b/llvm/include/llvm/Support/MachO.h
index 59998ada0204..b2ac6b3b5b67 100644
--- a/llvm/include/llvm/Support/MachO.h
+++ b/llvm/include/llvm/Support/MachO.h
@@ -14,13 +14,14 @@
 #ifndef LLVM_SUPPORT_MACHO_H
 #define LLVM_SUPPORT_MACHO_H
 
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/Host.h"
 
 namespace llvm {
   namespace MachO {
     // Enums from <mach-o/loader.h>
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Constants for the "magic" field in llvm::MachO::mach_header and
       // llvm::MachO::mach_header_64
       MH_MAGIC    = 0xFEEDFACEu,
@@ -75,12 +76,12 @@ namespace llvm {
       MH_DEAD_STRIPPABLE_DYLIB   = 0x00400000u
     };
 
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Flags for the "cmd" field in llvm::MachO::load_command
       LC_REQ_DYLD    = 0x80000000u
     };
 
-    enum LoadCommandType {
+    enum LoadCommandType LLVM_ENUM_INT_TYPE(uint32_t) {
       // Constants for the "cmd" field in llvm::MachO::load_command
       LC_SEGMENT              = 0x00000001u,
       LC_SYMTAB               = 0x00000002u,
@@ -130,7 +131,7 @@ namespace llvm {
       LC_LINKER_OPTIONS       = 0x0000002Du
     };
 
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Constant bits for the "flags" field in llvm::MachO::segment_command
       SG_HIGHVM              = 0x1u,
       SG_FVMLIB              = 0x2u,
@@ -173,7 +174,7 @@ namespace llvm {
       S_THREAD_LOCAL_INIT_FUNCTION_POINTERS = 0x15u
     };
 
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Constant masks for the "flags[31:24]" field in llvm::MachO::section and
       // llvm::MachO::section_64 (mask "flags" with SECTION_ATTRIBUTES_USR)
       S_ATTR_PURE_INSTRUCTIONS   = 0x80000000u,
@@ -235,9 +236,9 @@ namespace llvm {
     };
 
     enum BindSpecialDylib {
-      BIND_SPECIAL_DYLIB_SELF            =  0u,
-      BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE = -1u,
-      BIND_SPECIAL_DYLIB_FLAT_LOOKUP     = -2u
+      BIND_SPECIAL_DYLIB_SELF            =  0,
+      BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE = -1,
+      BIND_SPECIAL_DYLIB_FLAT_LOOKUP     = -2
     };
 
     enum {
@@ -347,7 +348,7 @@ namespace llvm {
       N_LENG    = 0xFEu
     };
 
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Constant values for the r_symbolnum field in an
       // llvm::MachO::relocation_info structure when r_extern is 0.
       R_ABS = 0,
@@ -892,7 +893,7 @@ namespace llvm {
     }
 
     // Enums from <mach/machine.h>
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Capability bits used in the definition of cpu_type.
       CPU_ARCH_MASK  = 0xff000000,   // Mask for architecture bits
       CPU_ARCH_ABI64 = 0x01000000    // 64 bit ABI
@@ -912,13 +913,13 @@ namespace llvm {
       CPU_TYPE_POWERPC64 = CPU_TYPE_POWERPC | CPU_ARCH_ABI64
     };
 
-    enum {
+    enum LLVM_ENUM_INT_TYPE(uint32_t) {
       // Capability bits used in the definition of cpusubtype.
       CPU_SUB_TYPE_MASK  = 0xff000000,   // Mask for architecture bits
       CPU_SUB_TYPE_LIB64 = 0x80000000,   // 64 bit libraries
 
       // Special CPU subtype constants.
-      CPU_SUBTYPE_MULTIPLE = -1
+      CPU_SUBTYPE_MULTIPLE = ~0u
     };
 
     // Constants for the cpusubtype field.