diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -15,6 +15,7 @@
 #ifndef LLVM_C_CORE_H
 #define LLVM_C_CORE_H
 
+#include "llvm-c/Deprecated.h"
 #include "llvm-c/ErrorHandling.h"
 #include "llvm-c/ExternC.h"
 #include "llvm-c/Types.h"
@@ -2378,9 +2379,10 @@
  * @{
  */
 
-/** Deprecated: Use LLVMAddAlias2 instead. */
-LLVMValueRef LLVMAddAlias(LLVMModuleRef M, LLVMTypeRef Ty, LLVMValueRef Aliasee,
-                          const char *Name);
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMAddAlias(LLVMModuleRef M, LLVMTypeRef Ty,
+                              LLVMValueRef Aliasee, const char *Name),
+    "Use LLVMAddAlias2 instead to support opaque pointers");
 
 /**
  * Add a GlobalAlias with the given value type, address space and aliasee.
@@ -3681,12 +3683,12 @@
                              LLVMBasicBlockRef Else, unsigned NumCases);
 LLVMValueRef LLVMBuildIndirectBr(LLVMBuilderRef B, LLVMValueRef Addr,
                                  unsigned NumDests);
-// LLVMBuildInvoke is deprecated in favor of LLVMBuildInvoke2, in preparation
-// for opaque pointer types.
-LLVMValueRef LLVMBuildInvoke(LLVMBuilderRef, LLVMValueRef Fn,
-                             LLVMValueRef *Args, unsigned NumArgs,
-                             LLVMBasicBlockRef Then, LLVMBasicBlockRef Catch,
-                             const char *Name);
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMBuildInvoke(LLVMBuilderRef, LLVMValueRef Fn,
+                                 LLVMValueRef *Args, unsigned NumArgs,
+                                 LLVMBasicBlockRef Then,
+                                 LLVMBasicBlockRef Catch, const char *Name),
+    "Use LLVMBuildInvoke2 instead to support opaque pointers");
 LLVMValueRef LLVMBuildInvoke2(LLVMBuilderRef, LLVMTypeRef Ty, LLVMValueRef Fn,
                               LLVMValueRef *Args, unsigned NumArgs,
                               LLVMBasicBlockRef Then, LLVMBasicBlockRef Catch,
@@ -3880,23 +3882,27 @@
 LLVMValueRef LLVMBuildArrayAlloca(LLVMBuilderRef, LLVMTypeRef Ty,
                                   LLVMValueRef Val, const char *Name);
 LLVMValueRef LLVMBuildFree(LLVMBuilderRef, LLVMValueRef PointerVal);
-// LLVMBuildLoad is deprecated in favor of LLVMBuildLoad2, in preparation for
-// opaque pointer types.
-LLVMValueRef LLVMBuildLoad(LLVMBuilderRef, LLVMValueRef PointerVal,
-                           const char *Name);
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMBuildLoad(LLVMBuilderRef, LLVMValueRef PointerVal,
+                               const char *Name),
+    "Use LLVMBuildLoad2 instead to support opaque pointers");
 LLVMValueRef LLVMBuildLoad2(LLVMBuilderRef, LLVMTypeRef Ty,
                             LLVMValueRef PointerVal, const char *Name);
 LLVMValueRef LLVMBuildStore(LLVMBuilderRef, LLVMValueRef Val, LLVMValueRef Ptr);
-// LLVMBuildGEP, LLVMBuildInBoundsGEP, and LLVMBuildStructGEP are deprecated in
-// favor of LLVMBuild*GEP2, in preparation for opaque pointer types.
-LLVMValueRef LLVMBuildGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
-                          LLVMValueRef *Indices, unsigned NumIndices,
-                          const char *Name);
-LLVMValueRef LLVMBuildInBoundsGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
-                                  LLVMValueRef *Indices, unsigned NumIndices,
-                                  const char *Name);
-LLVMValueRef LLVMBuildStructGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
-                                unsigned Idx, const char *Name);
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMBuildGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
+                              LLVMValueRef *Indices, unsigned NumIndices,
+                              const char *Name),
+    "Use LLVMBuildGEP2 instead to support opaque pointers");
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMBuildInBoundsGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
+                                      LLVMValueRef *Indices,
+                                      unsigned NumIndices, const char *Name),
+    "Use LLVMBuildInBoundsGEP2 instead to support opaque pointers");
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMBuildStructGEP(LLVMBuilderRef B, LLVMValueRef Pointer,
+                                    unsigned Idx, const char *Name),
+    "Use LLVMBuildStructGEP2 instead to support opaque pointers");
 LLVMValueRef LLVMBuildGEP2(LLVMBuilderRef B, LLVMTypeRef Ty,
                            LLVMValueRef Pointer, LLVMValueRef *Indices,
                            unsigned NumIndices, const char *Name);
@@ -3976,11 +3982,11 @@
 
 /* Miscellaneous instructions */
 LLVMValueRef LLVMBuildPhi(LLVMBuilderRef, LLVMTypeRef Ty, const char *Name);
-// LLVMBuildCall is deprecated in favor of LLVMBuildCall2, in preparation for
-// opaque pointer types.
-LLVMValueRef LLVMBuildCall(LLVMBuilderRef, LLVMValueRef Fn,
-                           LLVMValueRef *Args, unsigned NumArgs,
-                           const char *Name);
+LLVM_ATTRIBUTE_C_DEPRECATED(
+    LLVMValueRef LLVMBuildCall(LLVMBuilderRef, LLVMValueRef Fn,
+                               LLVMValueRef *Args, unsigned NumArgs,
+                               const char *Name),
+    "Use LLVMBuildCall2 instead to support opaque pointers");
 LLVMValueRef LLVMBuildCall2(LLVMBuilderRef, LLVMTypeRef, LLVMValueRef Fn,
                             LLVMValueRef *Args, unsigned NumArgs,
                             const char *Name);
diff --git a/llvm/include/llvm-c/Deprecated.h b/llvm/include/llvm-c/Deprecated.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm-c/Deprecated.h
@@ -0,0 +1,38 @@
+/*===-- llvm-c/Deprecated.h - Deprecation macro -------------------*- C -*-===*\
+|*                                                                            *|
+|* Part of the LLVM Project, under the Apache License v2.0 with LLVM          *|
+|* Exceptions.                                                                *|
+|* See https://llvm.org/LICENSE.txt for license information.                  *|
+|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception                    *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* This header declares LLVM_ATTRIBUTE_C_DEPRECATED() macro, which can be     *|
+|* used to deprecate functions in the C interface.                            *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#ifndef LLVM_C_DEPRECATED_H
+#define LLVM_C_DEPRECATED_H
+
+#ifndef __has_feature
+# define __has_feature(x) 0
+#endif
+
+// This is a variant of LLVM_ATTRIBUTE_DEPRECATED() that is compatible with
+// C compilers.
+#if __has_feature(attribute_deprecated_with_message)
+# define LLVM_ATTRIBUTE_C_DEPRECATED(decl, message) \
+  decl __attribute__((deprecated(message)))
+#elif defined(__GNUC__)
+# define LLVM_ATTRIBUTE_C_DEPRECATED(decl, message) \
+  decl __attribute__((deprecated))
+#elif defined(_MSC_VER)
+# define LLVM_ATTRIBUTE_C_DEPRECATED(decl, message) \
+  __declspec(deprecated(message)) decl
+#else
+# define LLVM_ATTRIBUTE_C_DEPRECATED(decl, message) \
+  decl
+#endif
+
+#endif /* LLVM_C_DEPRECATED_H */