diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -19,14 +19,15 @@
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/TargetCXXABI.h"
 #include "clang/Basic/TargetOptions.h"
+#include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
-#include "llvm/IR/DataLayout.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/VersionTuple.h"
 #include <cassert>
@@ -35,6 +36,7 @@
 
 namespace llvm {
 struct fltSemantics;
+class DataLayout;
 }
 
 namespace clang {
@@ -198,9 +200,7 @@
   // TargetInfo Constructor.  Default initializes all fields.
   TargetInfo(const llvm::Triple &T);
 
-  void resetDataLayout(StringRef DL) {
-    DataLayout.reset(new llvm::DataLayout(DL));
-  }
+  void resetDataLayout(StringRef DL);
 
 public:
   /// Construct a target for the given options.
diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp
--- a/clang/lib/Basic/TargetInfo.cpp
+++ b/clang/lib/Basic/TargetInfo.cpp
@@ -17,6 +17,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/DataLayout.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TargetParser.h"
 #include <cstdlib>
@@ -136,6 +137,10 @@
 // Out of line virtual dtor for TargetInfo.
 TargetInfo::~TargetInfo() {}
 
+void TargetInfo::resetDataLayout(StringRef DL) {
+  DataLayout.reset(new llvm::DataLayout(DL));
+}
+
 bool
 TargetInfo::checkCFProtectionBranchSupported(DiagnosticsEngine &Diags) const {
   Diags.Report(diag::err_opt_not_valid_on_target) << "cf-protection=branch";
diff --git a/clang/lib/Basic/Targets/AMDGPU.cpp b/clang/lib/Basic/Targets/AMDGPU.cpp
--- a/clang/lib/Basic/Targets/AMDGPU.cpp
+++ b/clang/lib/Basic/Targets/AMDGPU.cpp
@@ -17,6 +17,7 @@
 #include "clang/Basic/MacroBuilder.h"
 #include "clang/Basic/TargetBuiltins.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/IR/DataLayout.h"
 
 using namespace clang;
 using namespace clang::targets;
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -24,6 +24,7 @@
 #include "clang/Lex/PreprocessorOptions.h"
 #include "clang/Serialization/ASTReader.h"
 #include "llvm/ADT/APFloat.h"
+#include "llvm/IR/DataLayout.h"
 using namespace clang;
 
 static bool MacroBodyEndsInBackslash(StringRef MacroBody) {
diff --git a/clang/unittests/AST/DeclTest.cpp b/clang/unittests/AST/DeclTest.cpp
--- a/clang/unittests/AST/DeclTest.cpp
+++ b/clang/unittests/AST/DeclTest.cpp
@@ -16,6 +16,7 @@
 #include "clang/Basic/LLVM.h"
 #include "clang/Tooling/Tooling.h"
 #include "gtest/gtest.h"
+#include "llvm/IR/DataLayout.h"
 
 using namespace clang::ast_matchers;
 using namespace clang::tooling;