diff --git a/compiler-rt/include/sanitizer/msan_interface.h b/compiler-rt/include/sanitizer/msan_interface.h
new file mode 100644
index 000000000000..1a76dd60599f
--- /dev/null
+++ b/compiler-rt/include/sanitizer/msan_interface.h
@@ -0,0 +1,124 @@
+//===-- msan_interface.h --------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of MemorySanitizer.
+//
+// Public interface header.
+//===----------------------------------------------------------------------===//
+#ifndef MSAN_INTERFACE_H
+#define MSAN_INTERFACE_H
+
+#include <sanitizer/common_interface_defs.h>
+
+using __sanitizer::uptr;
+using __sanitizer::sptr;
+using __sanitizer::u32;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// FIXME: document all interface functions.
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __msan_get_track_origins();
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_init();
+
+// Print a warning and maybe return.
+// This function can die based on flags()->exit_code.
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_warning();
+
+// Print a warning and die.
+// Intrumentation inserts calls to this function when building in "fast" mode
+// (i.e. -mllvm -msan-keep-going)
+SANITIZER_INTERFACE_ATTRIBUTE __attribute__((noreturn))
+void __msan_warning_noreturn();
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_unpoison(void *a, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_clear_and_unpoison(void *a, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void* __msan_memcpy(void *dst, const void *src, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void* __msan_memset(void *s, int c, uptr n);
+SANITIZER_INTERFACE_ATTRIBUTE
+void* __msan_memmove(void* dest, const void* src, uptr n);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_copy_poison(void *dst, const void *src, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_copy_origin(void *dst, const void *src, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_move_poison(void *dst, const void *src, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_poison(void *a, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_poison_stack(void *a, uptr size);
+
+// Copy size bytes from src to dst and unpoison the result.
+// Useful to implement unsafe loads.
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_load_unpoisoned(void *src, uptr size, void *dst);
+
+// Returns the offset of the first (at least partially) poisoned byte,
+// or -1 if the whole range is good.
+SANITIZER_INTERFACE_ATTRIBUTE
+sptr __msan_test_shadow(const void *x, uptr size);
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_set_origin(void *a, uptr size, u32 origin);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_set_alloca_origin(void *a, uptr size, const char *descr);
+SANITIZER_INTERFACE_ATTRIBUTE
+u32 __msan_get_origin(void *a);
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_clear_on_return();
+
+// Default: -1 (don't exit on error).
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_set_exit_code(int exit_code);
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __msan_set_poison_in_malloc(int do_poison);
+
+// For testing.
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_set_expect_umr(int expect_umr);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_break_optimization(void *x);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_print_shadow(const void *x, uptr size);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_print_param_shadow();
+SANITIZER_INTERFACE_ATTRIBUTE
+int  __msan_has_dynamic_component();
+
+// Returns x such that %fs:x is the first byte of __msan_retval_tls.
+SANITIZER_INTERFACE_ATTRIBUTE
+int __msan_get_retval_tls_offset();
+SANITIZER_INTERFACE_ATTRIBUTE
+int __msan_get_param_tls_offset();
+
+// For testing.
+SANITIZER_INTERFACE_ATTRIBUTE
+u32 __msan_get_origin_tls();
+SANITIZER_INTERFACE_ATTRIBUTE
+const char *__msan_get_origin_descr_if_stack(u32 id);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_partial_poison(void* data, void* shadow, uptr size);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif