diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
index b13181f6e70894..0807d8877591a6 100644
--- a/clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -804,4 +804,7 @@ def warn_android_unversioned_fallback : Warning<
 
 def err_drv_triple_version_invalid : Error<
   "version '%0' in target triple '%1' is invalid">;
+
+def err_drv_installapi_unsupported : Error<
+  "InstallAPI is not supported for '%0'">;
 }
diff --git a/clang/include/clang/Driver/Action.h b/clang/include/clang/Driver/Action.h
index 04fa8b01b418f8..2768e2f5df1a9e 100644
--- a/clang/include/clang/Driver/Action.h
+++ b/clang/include/clang/Driver/Action.h
@@ -59,6 +59,7 @@ class Action {
     PreprocessJobClass,
     PrecompileJobClass,
     ExtractAPIJobClass,
+    InstallAPIJobClass,
     AnalyzeJobClass,
     MigrateJobClass,
     CompileJobClass,
@@ -448,6 +449,17 @@ class ExtractAPIJobAction : public JobAction {
   void addHeaderInput(Action *Input) { getInputs().push_back(Input); }
 };
 
+class InstallAPIJobAction : public JobAction {
+  void anchor() override;
+
+public:
+  InstallAPIJobAction(Action *Input, types::ID OutputType);
+
+  static bool classof(const Action *A) {
+    return A->getKind() == InstallAPIJobClass;
+  }
+};
+
 class AnalyzeJobAction : public JobAction {
   void anchor() override;
 
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index c625d0dd1c0c72..95b464e7d61834 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -309,6 +309,8 @@ class AnalyzerOpts<string base>
   : KeyPathAndMacro<"AnalyzerOpts->", base, "ANALYZER_"> {}
 class MigratorOpts<string base>
   : KeyPathAndMacro<"MigratorOpts.", base, "MIGRATOR_"> {}
+class InstallAPIOpts<string base>
+  : KeyPathAndMacro<"InstallAPIOpts.", base, "INSTALLAPI_"> {}
 
 // A boolean option which is opt-in in CC1. The positive option exists in CC1 and
 // Args.hasArg(OPT_ffoo) can be used to check that the flag is enabled.
@@ -1114,7 +1116,8 @@ def config_user_dir_EQ : Joined<["--"], "config-user-dir=">,
 def coverage : Flag<["-", "--"], "coverage">, Group<Link_Group>,
   Visibility<[ClangOption, CLOption]>;
 def cpp_precomp : Flag<["-"], "cpp-precomp">, Group<clang_ignored_f_Group>;
-def current__version : JoinedOrSeparate<["-"], "current_version">;
+def current__version : JoinedOrSeparate<["-"], "current_version">,
+  Visibility<[ClangOption, CC1Option]>;
 def cxx_isystem : JoinedOrSeparate<["-"], "cxx-isystem">, Group<clang_i_Group>,
   HelpText<"Add directory to the C++ SYSTEM include search path">,
   Visibility<[ClangOption, CC1Option]>,
@@ -1529,6 +1532,9 @@ def static_libsan : Flag<["-"], "static-libsan">,
   HelpText<"Statically link the sanitizer runtime (Not supported for ASan, TSan or UBSan on darwin)">;
 def : Flag<["-"], "shared-libasan">, Alias<shared_libsan>;
 def fasm : Flag<["-"], "fasm">, Group<f_Group>;
+def installapi : Flag<["-"], "installapi">,
+  Visibility<[ClangOption, CC1Option]>, Group<Action_Group>,
+  HelpText<"Create a text-based stub file by scanning header files">;
 
 defm assume_unique_vtables : BoolFOption<"assume-unique-vtables",
   CodeGenOpts<"AssumeUniqueVTables">, DefaultTrue,
@@ -4291,7 +4297,9 @@ def verify_pch : Flag<["-"], "verify-pch">, Group<Action_Group>,
   Visibility<[ClangOption, CC1Option]>,
   HelpText<"Load and verify that a pre-compiled header file is not stale">;
 def init : Separate<["-"], "init">;
-def install__name : Separate<["-"], "install_name">;
+def install__name : Separate<["-"], "install_name">,
+  Visibility<[ClangOption, CC1Option]>,
+  MarshallingInfoString<InstallAPIOpts<"InstallName">>;
 def iprefix : JoinedOrSeparate<["-"], "iprefix">, Group<clang_i_Group>,
   Visibility<[ClangOption, CC1Option]>,
   HelpText<"Set the -iwithprefix/-iwithprefixbefore prefix">, MetaVarName<"<dir>">;
diff --git a/clang/include/clang/Driver/Types.def b/clang/include/clang/Driver/Types.def
index f72c27e1ee7019..570a53441d1c74 100644
--- a/clang/include/clang/Driver/Types.def
+++ b/clang/include/clang/Driver/Types.def
@@ -94,6 +94,7 @@ TYPE("lto-bc",                   LTO_BC,       INVALID,         "o",      phases
 TYPE("ast",                      AST,          INVALID,         "ast",    phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("ifs",                      IFS,          INVALID,         "ifs",    phases::IfsMerge)
 TYPE("ifs-cpp",                  IFS_CPP,      INVALID,         "ifs",    phases::Compile, phases::IfsMerge)
+TYPE("tbd",                      TextAPI,      INVALID,         "tbd",    phases::Precompile)
 TYPE("pcm",                      ModuleFile,   INVALID,         "pcm",    phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("header-unit",              HeaderUnit,   INVALID,         "pcm",    phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("plist",                    Plist,        INVALID,         "plist",  phases::Compile, phases::Backend, phases::Assemble, phases::Link)
diff --git a/clang/include/clang/Frontend/CompilerInstance.h b/clang/include/clang/Frontend/CompilerInstance.h
index ac2f940769fbe9..6eb7972f86ca5b 100644
--- a/clang/include/clang/Frontend/CompilerInstance.h
+++ b/clang/include/clang/Frontend/CompilerInstance.h
@@ -294,6 +294,13 @@ class CompilerInstance : public ModuleLoader {
     return Invocation->getFrontendOpts();
   }
 
+  InstallAPIOptions &getInstallAPIOpts() {
+    return Invocation->getInstallAPIOpts();
+  }
+  const InstallAPIOptions &getInstallAPIOpts() const {
+    return Invocation->getInstallAPIOpts();
+  }
+
   HeaderSearchOptions &getHeaderSearchOpts() {
     return Invocation->getHeaderSearchOpts();
   }
diff --git a/clang/include/clang/Frontend/CompilerInvocation.h b/clang/include/clang/Frontend/CompilerInvocation.h
index c6528779bde7b2..a01d9695dce203 100644
--- a/clang/include/clang/Frontend/CompilerInvocation.h
+++ b/clang/include/clang/Frontend/CompilerInvocation.h
@@ -18,11 +18,12 @@
 #include "clang/Basic/LangStandard.h"
 #include "clang/Frontend/DependencyOutputOptions.h"
 #include "clang/Frontend/FrontendOptions.h"
+#include "clang/Frontend/InstallAPIOptions.h"
 #include "clang/Frontend/MigratorOptions.h"
 #include "clang/Frontend/PreprocessorOutputOptions.h"
 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
-#include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include <memory>
 #include <string>
 
@@ -111,6 +112,9 @@ class CompilerInvocationBase {
   /// Options controlling preprocessed output.
   std::shared_ptr<PreprocessorOutputOptions> PreprocessorOutputOpts;
 
+  /// Options controlling InstallAPI operations and output.
+  std::shared_ptr<InstallAPIOptions> InstallAPIOpts;
+
   /// Dummy tag type whose instance can be passed into the constructor to
   /// prevent creation of the reference-counted option objects.
   struct EmptyConstructor {};
@@ -145,6 +149,7 @@ class CompilerInvocationBase {
   const PreprocessorOutputOptions &getPreprocessorOutputOpts() const {
     return *PreprocessorOutputOpts;
   }
+  const InstallAPIOptions &getInstallAPIOpts() const { return *InstallAPIOpts; }
   /// @}
 
   /// Command line generation.
@@ -237,6 +242,7 @@ class CompilerInvocation : public CompilerInvocationBase {
   using CompilerInvocationBase::getFrontendOpts;
   using CompilerInvocationBase::getDependencyOutputOpts;
   using CompilerInvocationBase::getPreprocessorOutputOpts;
+  using CompilerInvocationBase::getInstallAPIOpts;
   /// @}
 
   /// Mutable getters.
@@ -258,6 +264,7 @@ class CompilerInvocation : public CompilerInvocationBase {
   PreprocessorOutputOptions &getPreprocessorOutputOpts() {
     return *PreprocessorOutputOpts;
   }
+  InstallAPIOptions &getInstallAPIOpts() { return *InstallAPIOpts; }
   /// @}
 
   /// Base class internals.
diff --git a/clang/include/clang/Frontend/FrontendActions.h b/clang/include/clang/Frontend/FrontendActions.h
index fcce31ac0590ff..b8229252f5ed22 100644
--- a/clang/include/clang/Frontend/FrontendActions.h
+++ b/clang/include/clang/Frontend/FrontendActions.h
@@ -130,6 +130,16 @@ class GenerateModuleAction : public ASTFrontendAction {
   bool shouldEraseOutputFiles() override;
 };
 
+class InstallAPIAction : public ASTFrontendAction {
+protected:
+  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
+                                                 StringRef InFile) override;
+
+public:
+  static std::unique_ptr<llvm::raw_pwrite_stream>
+  CreateOutputFile(CompilerInstance &CI, StringRef InFile);
+};
+
 class GenerateInterfaceStubsAction : public ASTFrontendAction {
 protected:
   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
index 53a8681cfdbba0..62d16ba542ea4d 100644
--- a/clang/include/clang/Frontend/FrontendOptions.h
+++ b/clang/include/clang/Frontend/FrontendOptions.h
@@ -100,6 +100,9 @@ enum ActionKind {
   /// Only execute frontend initialization.
   InitOnly,
 
+  // Create TextAPI stub.
+  InstallAPI,
+
   /// Dump information about a module file.
   ModuleFileInfo,
 
diff --git a/clang/include/clang/Frontend/InstallAPIOptions.h b/clang/include/clang/Frontend/InstallAPIOptions.h
new file mode 100644
index 00000000000000..cf65a3350c6de6
--- /dev/null
+++ b/clang/include/clang/Frontend/InstallAPIOptions.h
@@ -0,0 +1,28 @@
+//===--- InstallAPIOptions.h ------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_FRONTEND_INSTALLAPIOPTIONS_H
+#define LLVM_CLANG_FRONTEND_INSTALLAPIOPTIONS_H
+
+#include "llvm/TextAPI/PackedVersion.h"
+
+namespace clang {
+
+/// InstallAPIOptions - Options for controlling InstallAPI verification and
+/// TextAPI output.
+class InstallAPIOptions {
+public:
+  /// The install name which is apart of the library's ID.
+  std::string InstallName;
+
+  /// The current version which is apart of the library's ID.
+  llvm::MachO::PackedVersion CurrentVersion;
+};
+} // namespace clang
+
+#endif
diff --git a/clang/include/clang/InstallAPI/Context.h b/clang/include/clang/InstallAPI/Context.h
new file mode 100644
index 00000000000000..a1ff7c12a2f835
--- /dev/null
+++ b/clang/include/clang/InstallAPI/Context.h
@@ -0,0 +1,65 @@
+//===- InstallAPI/Context.h -------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Top level types for interacting with the generic clang driver and frontend
+// for InstallAPI operations.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INSTALLAPI_CONTEXT_H
+#define LLVM_CLANG_INSTALLAPI_CONTEXT_H
+
+#include "clang/AST/ASTConsumer.h"
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/TextAPI/InterfaceFile.h"
+#include "llvm/TextAPI/RecordVisitor.h"
+#include "llvm/TextAPI/RecordsSlice.h"
+
+namespace clang {
+namespace installapi {
+
+/// Struct used for generating validating InstallAPI.
+/// The attributes captured represent all necessary information
+/// to generate TextAPI output.
+struct InstallAPIContext {
+
+  /// Library attributes that are typically passed as linker inputs.
+  llvm::MachO::RecordsSlice::BinaryAttrs BA;
+
+  /// Active target triple to parse.
+  llvm::Triple TargetTriple{};
+
+  /// Output stream to write TextAPI file to.
+  std::unique_ptr<llvm::raw_pwrite_stream> OS = nullptr;
+
+  /// DiagnosticsEngine to report errors.
+  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diags = nullptr;
+
+  /// File Path of output location.
+  StringRef OutputLoc{};
+
+  /// What encoding to write output as.
+  llvm::MachO::FileType FT = llvm::MachO::FileType::TBD_V5;
+};
+
+class InstallAPIConsumer : public ASTConsumer {
+public:
+  InstallAPIConsumer(InstallAPIContext InstallAPICtx)
+      : Ctx(std::move(InstallAPICtx)) {}
+
+  void HandleTranslationUnit(ASTContext &ASTContext) override;
+
+private:
+  InstallAPIContext Ctx;
+};
+
+} // namespace installapi
+} // namespace clang
+
+#endif // LLVM_CLANG_INSTALLAPI_CONTEXT_H
diff --git a/clang/lib/CMakeLists.txt b/clang/lib/CMakeLists.txt
index 1526d65795f8ad..0cac86451f39e4 100644
--- a/clang/lib/CMakeLists.txt
+++ b/clang/lib/CMakeLists.txt
@@ -23,6 +23,7 @@ add_subdirectory(Tooling)
 add_subdirectory(DirectoryWatcher)
 add_subdirectory(Index)
 add_subdirectory(IndexSerialization)
+add_subdirectory(InstallAPI)
 add_subdirectory(StaticAnalyzer)
 add_subdirectory(Format)
 if(CLANG_INCLUDE_TESTS)
diff --git a/clang/lib/Driver/Action.cpp b/clang/lib/Driver/Action.cpp
index 849bf6035ebd2e..7b1a1bb0228c41 100644
--- a/clang/lib/Driver/Action.cpp
+++ b/clang/lib/Driver/Action.cpp
@@ -32,6 +32,8 @@ const char *Action::getClassName(ActionClass AC) {
   case CompileJobClass: return "compiler";
   case BackendJobClass: return "backend";
   case AssembleJobClass: return "assembler";
+  case InstallAPIJobClass:
+    return "installapi";
   case IfsMergeJobClass: return "interface-stub-merger";
   case LinkJobClass: return "linker";
   case LipoJobClass: return "lipo";
@@ -362,6 +364,11 @@ void ExtractAPIJobAction::anchor() {}
 ExtractAPIJobAction::ExtractAPIJobAction(Action *Inputs, types::ID OutputType)
     : JobAction(ExtractAPIJobClass, Inputs, OutputType) {}
 
+void InstallAPIJobAction::anchor() {}
+
+InstallAPIJobAction::InstallAPIJobAction(Action *Inputs, types::ID OutputType)
+    : JobAction(InstallAPIJobClass, Inputs, OutputType) {}
+
 void AnalyzeJobAction::anchor() {}
 
 AnalyzeJobAction::AnalyzeJobAction(Action *Input, types::ID OutputType)
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 00e14071a4afec..cf84ef21dfa8ce 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -4189,6 +4189,11 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
         break;
       }
 
+      if (auto *IAA = dyn_cast<InstallAPIJobAction>(Current)) {
+        Current = nullptr;
+        break;
+      }
+
       // FIXME: Should we include any prior module file outputs as inputs of
       // later actions in the same command line?
 
@@ -4319,6 +4324,13 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
     if (!MergerInputs.empty())
       Actions.push_back(
           C.MakeAction<IfsMergeJobAction>(MergerInputs, types::TY_Image));
+  } else if (Args.hasArg(options::OPT_installapi)) {
+    // TODO: Lift restriction once operation can handle multiple inputs.
+    assert(Inputs.size() == 1 && "InstallAPI action can only handle 1 input");
+    const auto [InputType, InputArg] = Inputs.front();
+    Action *Current = C.MakeAction<InputAction>(*InputArg, InputType);
+    Actions.push_back(
+        C.MakeAction<InstallAPIJobAction>(Current, types::TY_TextAPI));
   }
 
   for (auto Opt : {options::OPT_print_supported_cpus,
@@ -4762,6 +4774,8 @@ Action *Driver::ConstructPhaseAction(
       return C.MakeAction<VerifyPCHJobAction>(Input, types::TY_Nothing);
     if (Args.hasArg(options::OPT_extract_api))
       return C.MakeAction<ExtractAPIJobAction>(Input, types::TY_API_INFO);
+    if (Args.hasArg(options::OPT_installapi))
+      return C.MakeAction<InstallAPIJobAction>(Input, types::TY_TextAPI);
     return C.MakeAction<CompileJobAction>(Input, types::TY_LLVM_BC);
   }
   case phases::Backend: {
@@ -6441,7 +6455,7 @@ bool Driver::ShouldUseClangCompiler(const JobAction &JA) const {
   // And say "no" if this is not a kind of action clang understands.
   if (!isa<PreprocessJobAction>(JA) && !isa<PrecompileJobAction>(JA) &&
       !isa<CompileJobAction>(JA) && !isa<BackendJobAction>(JA) &&
-      !isa<ExtractAPIJobAction>(JA))
+      !isa<ExtractAPIJobAction>(JA) && !isa<InstallAPIJobAction>(JA))
     return false;
 
   return true;
diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index 388030592b4836..657577cea6c7d8 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -532,6 +532,7 @@ Tool *ToolChain::getTool(Action::ActionClass AC) const {
   case Action::PrecompileJobClass:
   case Action::PreprocessJobClass:
   case Action::ExtractAPIJobClass:
+  case Action::InstallAPIJobClass:
   case Action::AnalyzeJobClass:
   case Action::MigrateJobClass:
   case Action::VerifyPCHJobClass:
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 4459d86e77d5d9..47305f798c5fee 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4939,6 +4939,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     if (Arg *ExtractAPIIgnoresFileArg =
             Args.getLastArg(options::OPT_extract_api_ignores_EQ))
       ExtractAPIIgnoresFileArg->render(Args, CmdArgs);
+  } else if (isa<InstallAPIJobAction>(JA)) {
+    if (!Triple.isOSDarwin())
+      D.Diag(diag::err_drv_installapi_unsupported) << Triple.str();
+
+    CmdArgs.push_back("-installapi");
+    // Add necessary library arguments for InstallAPI.
+    if (const Arg *A = Args.getLastArg(options::OPT_install__name))
+      A->render(Args, CmdArgs);
+    if (const Arg *A = Args.getLastArg(options::OPT_current__version))
+      A->render(Args, CmdArgs);
+
   } else {
     assert((isa<CompileJobAction>(JA) || isa<BackendJobAction>(JA)) &&
            "Invalid action for clang tool.");
diff --git a/clang/lib/Frontend/CMakeLists.txt b/clang/lib/Frontend/CMakeLists.txt
index a9166672088459..f443d88b5d30cb 100644
--- a/clang/lib/Frontend/CMakeLists.txt
+++ b/clang/lib/Frontend/CMakeLists.txt
@@ -7,6 +7,7 @@ set(LLVM_LINK_COMPONENTS
   ProfileData
   Support
   TargetParser
+  TextAPI
   )
 
 add_clang_library(clangFrontend
@@ -27,6 +28,7 @@ add_clang_library(clangFrontend
   HeaderIncludeGen.cpp
   InitPreprocessor.cpp
   LayoutOverrideSource.cpp
+  InstallAPIConsumer.cpp
   LogDiagnosticPrinter.cpp
   ModuleDependencyCollector.cpp
   MultiplexConsumer.cpp
@@ -53,6 +55,7 @@ add_clang_library(clangFrontend
   clangBasic
   clangDriver
   clangEdit
+  clangInstallAPI
   clangLex
   clangParse
   clangSema
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 8d7b75b56d6129..bcb31243056b7e 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -149,7 +149,8 @@ CompilerInvocationBase::CompilerInvocationBase()
       FSOpts(std::make_shared<FileSystemOptions>()),
       FrontendOpts(std::make_shared<FrontendOptions>()),
       DependencyOutputOpts(std::make_shared<DependencyOutputOptions>()),
-      PreprocessorOutputOpts(std::make_shared<PreprocessorOutputOptions>()) {}
+      PreprocessorOutputOpts(std::make_shared<PreprocessorOutputOptions>()),
+      InstallAPIOpts(std::make_shared<InstallAPIOptions>()) {}
 
 CompilerInvocationBase &
 CompilerInvocationBase::deep_copy_assign(const CompilerInvocationBase &X) {
@@ -167,6 +168,7 @@ CompilerInvocationBase::deep_copy_assign(const CompilerInvocationBase &X) {
     FrontendOpts = make_shared_copy(X.getFrontendOpts());
     DependencyOutputOpts = make_shared_copy(X.getDependencyOutputOpts());
     PreprocessorOutputOpts = make_shared_copy(X.getPreprocessorOutputOpts());
+    InstallAPIOpts = make_shared_copy(X.getInstallAPIOpts());
   }
   return *this;
 }
@@ -187,6 +189,7 @@ CompilerInvocationBase::shallow_copy_assign(const CompilerInvocationBase &X) {
     FrontendOpts = X.FrontendOpts;
     DependencyOutputOpts = X.DependencyOutputOpts;
     PreprocessorOutputOpts = X.PreprocessorOutputOpts;
+    InstallAPIOpts = X.InstallAPIOpts;
   }
   return *this;
 }
@@ -2158,6 +2161,34 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
   return Diags.getNumErrors() == NumErrorsBefore;
 }
 
+static bool ParseInstallAPIArgs(InstallAPIOptions &Opts, ArgList &Args,
+                                DiagnosticsEngine &Diags,
+                                frontend::ActionKind Action) {
+  unsigned NumErrorsBefore = Diags.getNumErrors();
+
+  InstallAPIOptions &InstallAPIOpts = Opts;
+#define INSTALLAPI_OPTION_WITH_MARSHALLING(...)                                \
+  PARSE_OPTION_WITH_MARSHALLING(Args, Diags, __VA_ARGS__)
+#include "clang/Driver/Options.inc"
+#undef INSTALLAPI_OPTION_WITH_MARSHALLING
+  if (Arg *A = Args.getLastArg(options::OPT_current__version))
+    Opts.CurrentVersion.parse64(A->getValue());
+
+  return Diags.getNumErrors() == NumErrorsBefore;
+}
+
+static void GenerateInstallAPIArgs(const InstallAPIOptions &Opts,
+                                   ArgumentConsumer Consumer) {
+  const InstallAPIOptions &InstallAPIOpts = Opts;
+#define INSTALLAPI_OPTION_WITH_MARSHALLING(...)                                \
+  GENERATE_OPTION_WITH_MARSHALLING(Consumer, __VA_ARGS__)
+#include "clang/Driver/Options.inc"
+#undef INSTALLAPI_OPTION_WITH_MARSHALLING
+  if (!Opts.CurrentVersion.empty())
+    GenerateArg(Consumer, OPT_current__version,
+                std::string(Opts.CurrentVersion));
+}
+
 static void GenerateDependencyOutputArgs(const DependencyOutputOptions &Opts,
                                          ArgumentConsumer Consumer) {
   const DependencyOutputOptions &DependencyOutputOpts = Opts;
@@ -2557,6 +2588,7 @@ static const auto &getFrontendActionTable() {
       {frontend::GeneratePCH, OPT_emit_pch},
       {frontend::GenerateInterfaceStubs, OPT_emit_interface_stubs},
       {frontend::InitOnly, OPT_init_only},
+      {frontend::InstallAPI, OPT_installapi},
       {frontend::ParseSyntaxOnly, OPT_fsyntax_only},
       {frontend::ModuleFileInfo, OPT_module_file_info},
       {frontend::VerifyPCH, OPT_verify_pch},
@@ -4280,6 +4312,7 @@ static bool isStrictlyPreprocessorAction(frontend::ActionKind Action) {
   case frontend::GenerateHeaderUnit:
   case frontend::GeneratePCH:
   case frontend::GenerateInterfaceStubs:
+  case frontend::InstallAPI:
   case frontend::ParseSyntaxOnly:
   case frontend::ModuleFileInfo:
   case frontend::VerifyPCH:
@@ -4654,6 +4687,11 @@ bool CompilerInvocation::CreateFromArgsImpl(
       Res.getDependencyOutputOpts().Targets.empty())
     Diags.Report(diag::err_fe_dependency_file_requires_MT);
 
+  if (Args.hasArg(OPT_installapi)) {
+    ParseInstallAPIArgs(Res.getInstallAPIOpts(), Args, Diags,
+                        Res.getFrontendOpts().ProgramAction);
+  }
+
   // If sanitizer is enabled, disable OPT_ffine_grained_bitfield_accesses.
   if (Res.getCodeGenOpts().FineGrainedBitfieldAccesses &&
       !Res.getLangOpts().Sanitize.empty()) {
@@ -4844,6 +4882,7 @@ void CompilerInvocationBase::generateCC1CommandLine(
   GeneratePreprocessorOutputArgs(getPreprocessorOutputOpts(), Consumer,
                                  getFrontendOpts().ProgramAction);
   GenerateDependencyOutputArgs(getDependencyOutputOpts(), Consumer);
+  GenerateInstallAPIArgs(getInstallAPIOpts(), Consumer);
 }
 
 std::vector<std::string> CompilerInvocationBase::getCC1CommandLine() const {
diff --git a/clang/lib/Frontend/InstallAPIConsumer.cpp b/clang/lib/Frontend/InstallAPIConsumer.cpp
new file mode 100644
index 00000000000000..c0f22c1a589f38
--- /dev/null
+++ b/clang/lib/Frontend/InstallAPIConsumer.cpp
@@ -0,0 +1,43 @@
+//===--- InstallAPIConsumer.cpp -------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/InstallAPI/Context.h"
+
+using namespace clang;
+using namespace clang::installapi;
+
+std::unique_ptr<ASTConsumer>
+InstallAPIAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
+  const InstallAPIOptions &Opts = CI.getInstallAPIOpts();
+  InstallAPIContext Ctx;
+  Ctx.BA.InstallName = Opts.InstallName;
+  Ctx.BA.AppExtensionSafe = CI.getLangOpts().AppExt;
+  Ctx.BA.CurrentVersion = Opts.CurrentVersion;
+  // InstallAPI requires two level namespacing.
+  Ctx.BA.TwoLevelNamespace = true;
+  Ctx.TargetTriple = CI.getTarget().getTriple();
+
+  Ctx.Diags = &CI.getDiagnostics();
+  Ctx.OutputLoc = CI.getFrontendOpts().OutputFile;
+  Ctx.OS = CreateOutputFile(CI, InFile);
+  if (!Ctx.OS)
+    return nullptr;
+  return std::make_unique<InstallAPIConsumer>(std::move(Ctx));
+}
+
+std::unique_ptr<llvm::raw_pwrite_stream>
+InstallAPIAction::CreateOutputFile(CompilerInstance &CI, StringRef InFile) {
+  std::unique_ptr<raw_pwrite_stream> OS =
+      CI.createDefaultOutputFile(/*Binary=*/false, InFile, /*Extension=*/"tbd",
+                                 /*RemoveFileOnSignal=*/false);
+  if (!OS)
+    return nullptr;
+  return OS;
+}
diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index 925879a68cbd09..a47c474e520a01 100644
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -71,6 +71,8 @@ CreateFrontendBaseAction(CompilerInstance &CI) {
   case GenerateInterfaceStubs:
     return std::make_unique<GenerateInterfaceStubsAction>();
   case InitOnly:               return std::make_unique<InitOnlyAction>();
+  case InstallAPI:
+    return std::make_unique<InstallAPIAction>();
   case ParseSyntaxOnly:        return std::make_unique<SyntaxOnlyAction>();
   case ModuleFileInfo:         return std::make_unique<DumpModuleInfoAction>();
   case VerifyPCH:              return std::make_unique<VerifyPCHAction>();
diff --git a/clang/lib/InstallAPI/CMakeLists.txt b/clang/lib/InstallAPI/CMakeLists.txt
new file mode 100644
index 00000000000000..b68d8fbbec1d37
--- /dev/null
+++ b/clang/lib/InstallAPI/CMakeLists.txt
@@ -0,0 +1,11 @@
+set(LLVM_LINK_COMPONENTS
+  Support
+  TextAPI
+  )
+
+add_clang_library(clangInstallAPI
+  Context.cpp
+
+  LINK_LIBS
+  clangAST
+  )
diff --git a/clang/lib/InstallAPI/Context.cpp b/clang/lib/InstallAPI/Context.cpp
new file mode 100644
index 00000000000000..d4df52f66560c1
--- /dev/null
+++ b/clang/lib/InstallAPI/Context.cpp
@@ -0,0 +1,27 @@
+//===--- InstallAPI/Context.cpp -------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/InstallAPI/Context.h"
+#include "clang/AST/ASTContext.h"
+#include "llvm/TextAPI/TextAPIWriter.h"
+
+using namespace clang;
+using namespace clang::installapi;
+using namespace llvm::MachO;
+
+void InstallAPIConsumer::HandleTranslationUnit(ASTContext &Context) {
+  if (Context.getDiagnostics().hasErrorOccurred())
+    return;
+  InterfaceFile IF;
+  // Set library attributes captured through cc1 args.
+  Target T(Ctx.TargetTriple);
+  IF.addTarget(T);
+  IF.setFromBinaryAttrs(Ctx.BA, T);
+  if (auto Err = TextAPIWriter::writeToStream(*Ctx.OS, IF, Ctx.FT))
+    Ctx.Diags->Report(diag::err_cannot_open_file) << Ctx.OutputLoc;
+}
diff --git a/clang/test/CMakeLists.txt b/clang/test/CMakeLists.txt
index f17ded42a019c2..841317cef880a2 100644
--- a/clang/test/CMakeLists.txt
+++ b/clang/test/CMakeLists.txt
@@ -131,6 +131,7 @@ if( NOT CLANG_BUILT_STANDALONE )
     llvm-rc
     llvm-readelf
     llvm-readobj
+    llvm-readtapi
     llvm-strip
     llvm-symbolizer
     llvm-windres
diff --git a/clang/test/Driver/installapi.h b/clang/test/Driver/installapi.h
new file mode 100644
index 00000000000000..99379b44d1379c
--- /dev/null
+++ b/clang/test/Driver/installapi.h
@@ -0,0 +1,13 @@
+// Check non-darwin triple is rejected.
+// RUN: not %clang -target x86_64-unknown-unknown -installapi %s 2> %t 
+// RUN: FileCheck --check-prefix INVALID_INSTALLAPI -input-file %t %s
+
+// INVALID_INSTALLAPI: error: InstallAPI is not supported for 'x86_64-unknown-unknown'
+
+// Check installapi phases.
+// RUN: %clang -target x86_64-apple-macos11 -ccc-print-phases -installapi %s 2> %t 
+// RUN: FileCheck --check-prefix INSTALLAPI_PHASES -input-file %t %s
+
+// INSTALLAPI_PHASES: 0: input,
+// INSTALLAPI_PHASES: installapi,
+// INSTALLAPI_PHASES-SAME: tbd 
diff --git a/clang/test/InstallAPI/installapi-basic.test b/clang/test/InstallAPI/installapi-basic.test
new file mode 100644
index 00000000000000..8035166d076dab
--- /dev/null
+++ b/clang/test/InstallAPI/installapi-basic.test
@@ -0,0 +1,34 @@
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: %clang_cc1 -x objective-c -triple arm64-apple-ios13.0.0 -installapi \
+// RUN: -fapplication-extension -current_version 1 -install_name /usr/lib/basic.dylib \
+// RUN: %t/basic_inputs.json -o %t/basic.tbd 2>&1 | FileCheck %s --allow-empty
+// RUN: llvm-readtapi -compare %t/basic.tbd %t/expected.tbd 2>&1 | FileCheck %s --allow-empty
+
+// CHECK-NOT: error:  
+// CHECK-NOT: warning:  
+
+//--- basic_inputs.json
+
+//--- expected.tbd
+{
+  "main_library": {
+    "compatibility_versions": [
+      {
+        "version": "0"
+      }
+    ],
+    "install_names": [
+      {
+        "name": "/usr/lib/basic.dylib"
+      }
+    ],
+    "target_info": [
+      {
+        "min_deployment": "13.0.0",
+        "target": "arm64-ios"
+      }
+    ]
+  },
+  "tapi_tbd_version": 5
+}
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index 271372b928ac55..f93b5d9c945886 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -97,6 +97,7 @@
     "llvm-lto",
     "llvm-lto2",
     "llvm-profdata",
+    "llvm-readtapi",
     ToolSubst(
         "%clang_extdef_map",
         command=FindTool("clang-extdef-mapping"),