diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -39,6 +39,7 @@
 #include "clang/Basic/SanitizerBlacklist.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
+#include "clang/Basic/TargetCXXABI.h"
 #include "clang/Basic/XRayLists.h"
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -697,6 +698,11 @@
     return FullSourceLoc(Loc,SourceMgr);
   }
 
+  /// Return the C++ ABI kind that should be used. This is located here so the
+  /// ABI can be overriden by Clang-specific flags at compile-time. If there are
+  /// no overrides, we instead use the default ABI specified by the target.
+  TargetCXXABI::Kind getCXXABIKind(const TargetInfo *T = nullptr) const;
+
   /// All comments in this translation unit.
   RawCommentList Comments;
 
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -327,6 +327,11 @@
   /// input is a header file (i.e. -x c-header).
   bool IsHeaderFile = false;
 
+  /// Indicates that the Fuchsia C++ ABI is being used, either by default
+  /// through the target triple (ARCH-VENDOR-fuchsia) or explicitly through
+  /// the -ffuchsia-c++-abi flag.
+  bool UseFuchsiaCXXABI;
+
   LangOptions();
 
   // Define accessors/mutators for language options of enumeration type.
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1370,6 +1370,11 @@
 def fsymbol_partition_EQ : Joined<["-"], "fsymbol-partition=">, Group<f_Group>,
   Flags<[CC1Option]>, MarshallingInfoString<"CodeGenOpts.SymbolPartition">;
 
+def ffuchsia_cxx_abi : Flag<["-"], "ffuchsia-c++-abi">, Flags<[CC1Option]>,
+             Group<f_Group>, HelpText<"Explicitly use the Fuchsia C++ ABI">;
+def fno_fuchsia_cxx_abi : Flag<["-"], "fno-fuchsia-c++-abi">, Flags<[CC1Option]>,
+             Group<f_Group>, HelpText<"Do not explicitly use the Fuchsia C++ ABI. Instead use the default C++ ABI indicated by the target">;
+
 defm memory_profile : OptInFFlag<"memory-profile", "Enable", "Disable", " heap memory profiling">;
 def fmemory_profile_EQ : Joined<["-"], "fmemory-profile=">,
     Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<directory>">,
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -879,10 +879,18 @@
   return CanonTTP;
 }
 
+TargetCXXABI::Kind ASTContext::getCXXABIKind(const TargetInfo *T) const {
+  if (getLangOpts().UseFuchsiaCXXABI)
+    return TargetCXXABI::Fuchsia;
+  if (T)
+    return T->getCXXABI().getKind();
+  return getTargetInfo().getCXXABI().getKind();
+}
+
 CXXABI *ASTContext::createCXXABI(const TargetInfo &T) {
   if (!LangOpts.CPlusPlus) return nullptr;
 
-  switch (T.getCXXABI().getKind()) {
+  switch (getCXXABIKind(&T)) {
   case TargetCXXABI::AppleARM64:
   case TargetCXXABI::Fuchsia:
   case TargetCXXABI::GenericARM: // Same as Itanium at this level
@@ -10875,7 +10883,7 @@
 MangleContext *ASTContext::createMangleContext(const TargetInfo *T) {
   if (!T)
     T = Target;
-  switch (T->getCXXABI().getKind()) {
+  switch (getCXXABIKind(T)) {
   case TargetCXXABI::AppleARM64:
   case TargetCXXABI::Fuchsia:
   case TargetCXXABI::GenericAArch64:
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -75,7 +75,7 @@
 static const char AnnotationSection[] = "llvm.metadata";
 
 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
-  switch (CGM.getTarget().getCXXABI().getKind()) {
+  switch (CGM.getContext().getCXXABIKind()) {
   case TargetCXXABI::AppleARM64:
   case TargetCXXABI::Fuchsia:
   case TargetCXXABI::GenericAArch64:
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -543,7 +543,7 @@
 }
 
 CodeGen::CGCXXABI *CodeGen::CreateItaniumCXXABI(CodeGenModule &CGM) {
-  switch (CGM.getTarget().getCXXABI().getKind()) {
+  switch (CGM.getContext().getCXXABIKind()) {
   // For IR-generation purposes, there's no significant difference
   // between the ARM and iOS ABIs.
   case TargetCXXABI::GenericARM:
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5120,6 +5120,11 @@
                    /*Default=*/false))
     Args.AddLastArg(CmdArgs, options::OPT_ffixed_point);
 
+  if (Args.hasFlag(options::OPT_ffuchsia_cxx_abi,
+                   options::OPT_fno_fuchsia_cxx_abi,
+                   /*Default=*/false))
+    Args.AddLastArg(CmdArgs, options::OPT_ffuchsia_cxx_abi);
+
   // Handle -{std, ansi, trigraphs} -- take the last of -{std, ansi}
   // (-ansi is equivalent to -std=c89 or -std=c++98).
   //
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2831,6 +2831,10 @@
     }
   }
 
+  Opts.UseFuchsiaCXXABI =
+      Args.hasFlag(OPT_ffuchsia_cxx_abi, OPT_fno_fuchsia_cxx_abi,
+                   /*default=*/T.isOSFuchsia());
+
   std::string ThreadModel =
       std::string(Args.getLastArgValue(OPT_mthread_model, "posix"));
   if (ThreadModel != "posix" && ThreadModel != "single")
diff --git a/clang/test/CodeGenCXX/constructor-destructor-return-this.cpp b/clang/test/CodeGenCXX/constructor-destructor-return-this.cpp
--- a/clang/test/CodeGenCXX/constructor-destructor-return-this.cpp
+++ b/clang/test/CodeGenCXX/constructor-destructor-return-this.cpp
@@ -5,6 +5,8 @@
 //RUN:   | FileCheck --check-prefix=CHECKARM %s
 //RUN: %clang_cc1 %s -emit-llvm -o - -triple=x86_64-unknown-fuchsia | FileCheck --check-prefix=CHECKFUCHSIA %s
 //RUN: %clang_cc1 %s -emit-llvm -o - -triple=aarch64-unknown-fuchsia | FileCheck --check-prefix=CHECKFUCHSIA %s
+//RUN: %clang_cc1 %s -emit-llvm -o - -triple=x86_64-unknown-linux-gnu -ffuchsia-c++-abi | FileCheck --check-prefix=CHECKFUCHSIA %s
+//RUN: %clang_cc1 %s -emit-llvm -o - -triple=x86_64-unknown-fuchsia -fno-fuchsia-c++-abi| FileCheck --check-prefix=CHECKFUCHSIA %s
 //RUN: %clang_cc1 %s -emit-llvm -o - -triple=i386-pc-win32 -fno-rtti | FileCheck --check-prefix=CHECKMS %s
 // FIXME: these tests crash on the bots when run with -triple=x86_64-pc-win32