1 files changed, 59 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/fuzzer/FuzzerBuiltinsMsvc.h b/contrib/compiler-rt/lib/fuzzer/FuzzerBuiltinsMsvc.h
new file mode 100644
index 000000000000..67dd57ff9a93
--- /dev/null
+++ b/contrib/compiler-rt/lib/fuzzer/FuzzerBuiltinsMsvc.h
@@ -0,0 +1,59 @@
+//===- FuzzerBuiltinsMSVC.h - Internal header for builtins ------*- C++ -* ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Wrapper functions and marcos that use intrinsics instead of builtin functions
+// which cannot be compiled by MSVC.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FUZZER_BUILTINS_MSVC_H
+#define LLVM_FUZZER_BUILTINS_MSVC_H
+
+#include "FuzzerDefs.h"
+
+#if LIBFUZZER_MSVC
+#if !defined(_M_ARM) && !defined(_M_X64)
+#error "_BitScanReverse64 unavailable on this platform so MSVC is unsupported."
+#endif
+#include <intrin.h>
+#include <cstdint>
+#include <cstdlib>
+
+// __builtin_return_address() cannot be compiled with MSVC. Use the equivalent
+// from <intrin.h>
+#define GET_CALLER_PC() reinterpret_cast<uintptr_t>(_ReturnAddress())
+
+namespace fuzzer {
+
+inline uint8_t  Bswap(uint8_t x)  { return x; }
+// Use alternatives to __builtin functions from <stdlib.h> and <intrin.h> on
+// Windows since the builtins are not supported by MSVC.
+inline uint16_t Bswap(uint16_t x) { return _byteswap_ushort(x); }
+inline uint32_t Bswap(uint32_t x) { return _byteswap_ulong(x); }
+inline uint64_t Bswap(uint64_t x) { return _byteswap_uint64(x); }
+
+// The functions below were mostly copied from
+// compiler-rt/lib/builtins/int_lib.h which defines the __builtin functions used
+// outside of Windows.
+inline uint32_t Clzll(uint64_t X) {
+  unsigned long LeadZeroIdx = 0;
+  if (_BitScanReverse64(&LeadZeroIdx, X)) return 63 - LeadZeroIdx;
+  return 64;
+}
+
+inline uint32_t Clz(uint32_t X) {
+  unsigned long LeadZeroIdx = 0;
+  if (_BitScanReverse(&LeadZeroIdx, X)) return 31 - LeadZeroIdx;
+  return 32;
+}
+
+inline int Popcountll(unsigned long long X) { return __popcnt64(X); }
+
+}  // namespace fuzzer
+
+#endif  // LIBFUZER_MSVC
+#endif  // LLVM_FUZZER_BUILTINS_MSVC_H