diff --git a/include/clang/Basic/DiagnosticCommonKinds.td b/include/clang/Basic/DiagnosticCommonKinds.td
index 711204a790f8..82ca27b7345e 100644
--- a/include/clang/Basic/DiagnosticCommonKinds.td
+++ b/include/clang/Basic/DiagnosticCommonKinds.td
@@ -94,9 +94,6 @@ def remark_module_lock_failure : Remark<
   "could not acquire lock file for module '%0': %1">, InGroup<ModuleBuild>;
 def remark_module_lock_timeout : Remark<
   "timed out waiting to acquire lock file for module '%0'">, InGroup<ModuleBuild>;
-def err_module_shadowed : Error<"import of shadowed module '%0'">, DefaultFatal;
-def err_module_build_shadowed_submodule : Error<
-  "build a shadowed submodule '%0'">, DefaultFatal;
 def err_module_cycle : Error<"cyclic dependency in module '%0': %1">, 
   DefaultFatal;
 def err_module_prebuilt : Error<
diff --git a/include/clang/Basic/Module.h b/include/clang/Basic/Module.h
index 3725fcb06db9..6631721e3531 100644
--- a/include/clang/Basic/Module.h
+++ b/include/clang/Basic/Module.h
@@ -197,9 +197,6 @@ class Module {
   /// will be false to indicate that this (sub)module is not available.
   SmallVector<Requirement, 2> Requirements;
 
-  /// \brief A module with the same name that shadows this module.
-  Module *ShadowingModule = nullptr;
-
   /// \brief Whether this module is missing a feature from \c Requirements.
   unsigned IsMissingRequirement : 1;
 
@@ -378,20 +375,13 @@ class Module {
   ///
   /// \param Target The target options used for the current translation unit.
   ///
-  /// \param Req If this module is unavailable because of a missing requirement,
-  /// this parameter will be set to one of the requirements that is not met for
-  /// use of this module.
-  ///
-  /// \param MissingHeader If this module is unavailable because of a missing
-  /// header, this parameter will be set to one of the missing headers.
-  ///
-  /// \param ShadowingModule If this module is unavailable because it is
-  /// shadowed, this parameter will be set to the shadowing module.
+  /// \param Req If this module is unavailable, this parameter
+  /// will be set to one of the requirements that is not met for use of
+  /// this module.
   bool isAvailable(const LangOptions &LangOpts, 
                    const TargetInfo &Target,
                    Requirement &Req,
-                   UnresolvedHeaderDirective &MissingHeader,
-                   Module *&ShadowingModule) const;
+                   UnresolvedHeaderDirective &MissingHeader) const;
 
   /// \brief Determine whether this module is a submodule.
   bool isSubModule() const { return Parent != nullptr; }
diff --git a/include/clang/Lex/HeaderSearch.h b/include/clang/Lex/HeaderSearch.h
index 73a5af1913ff..6b9dbfcd1e93 100644
--- a/include/clang/Lex/HeaderSearch.h
+++ b/include/clang/Lex/HeaderSearch.h
@@ -726,7 +726,6 @@ class HeaderSearch {
   LoadModuleMapResult loadModuleMapFileImpl(const FileEntry *File,
                                             bool IsSystem,
                                             const DirectoryEntry *Dir,
-                                            bool IsExplicitlyProvided,
                                             FileID ID = FileID(),
                                             unsigned *Offset = nullptr);
 
diff --git a/include/clang/Lex/ModuleMap.h b/include/clang/Lex/ModuleMap.h
index 1f3377e5214d..41ed8e49b6c1 100644
--- a/include/clang/Lex/ModuleMap.h
+++ b/include/clang/Lex/ModuleMap.h
@@ -195,17 +195,6 @@ class ModuleMap {
   /// header.
   llvm::DenseMap<const DirectoryEntry *, Module *> UmbrellaDirs;
 
-  /// \brief The set of modules provided explicitly (e.g. by -fmodule-map-file),
-  /// which are allowed to shadow other implicitly discovered modules.
-  llvm::DenseSet<const Module *> ExplicitlyProvidedModules;
-
-  bool mayShadowModuleBeingParsed(Module *ExistingModule,
-                                  bool IsExplicitlyProvided) {
-    assert(!ExistingModule->Parent && "expected top-level module");
-    return !IsExplicitlyProvided &&
-           ExplicitlyProvidedModules.count(ExistingModule);
-  }
-
   /// \brief The set of attributes that can be attached to a module.
   struct Attributes {
     /// \brief Whether this is a system module.
@@ -486,9 +475,9 @@ class ModuleMap {
   ///
   /// \returns The found or newly-created module, along with a boolean value
   /// that will be true if the module is newly-created.
-  std::pair<Module *, bool>
-  findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
-                     bool IsExplicit, bool UsesExplicitModuleMapFile = false);
+  std::pair<Module *, bool> findOrCreateModule(StringRef Name, Module *Parent,
+                                               bool IsFramework,
+                                               bool IsExplicit);
 
   /// \brief Create a 'global module' for a C++ Modules TS module interface
   /// unit.
@@ -513,11 +502,6 @@ class ModuleMap {
   Module *inferFrameworkModule(const DirectoryEntry *FrameworkDir,
                                bool IsSystem, Module *Parent);
 
-  /// \brief Create a new top-level module that is shadowed by
-  /// \p ShadowingModule.
-  Module *createShadowedModule(StringRef Name, bool IsFramework,
-                               Module *ShadowingModule);
-
   /// \brief Retrieve the module map file containing the definition of the given
   /// module.
   ///
@@ -603,8 +587,6 @@ class ModuleMap {
   /// \brief Marks this header as being excluded from the given module.
   void excludeHeader(Module *Mod, Module::Header Header);
 
-  void setExplicitlyProvided(Module *Mod);
-
   /// \brief Parse the given module map file, and record any modules we 
   /// encounter.
   ///
@@ -624,15 +606,10 @@ class ModuleMap {
   /// \param ExternModuleLoc The location of the "extern module" declaration
   ///        that caused us to load this module map file, if any.
   ///
-  /// \param IsExplicitlyProvided Whether this module map file was provided
-  /// explicitly by the user (e.g. -fmodule-map-file), rather than found
-  /// implicitly.
-  ///
   /// \returns true if an error occurred, false otherwise.
   bool parseModuleMapFile(const FileEntry *File, bool IsSystem,
-                          const DirectoryEntry *HomeDir,
-                          bool IsExplicitlyProvided = false,
-                          FileID ID = FileID(), unsigned *Offset = nullptr,
+                          const DirectoryEntry *HomeDir, FileID ID = FileID(),
+                          unsigned *Offset = nullptr,
                           SourceLocation ExternModuleLoc = SourceLocation());
 
   /// \brief Dump the contents of the module map, for debugging purposes.
diff --git a/lib/Basic/Module.cpp b/lib/Basic/Module.cpp
index 692e138f6c15..7124184865c6 100644
--- a/lib/Basic/Module.cpp
+++ b/lib/Basic/Module.cpp
@@ -95,16 +95,11 @@ static bool hasFeature(StringRef Feature, const LangOptions &LangOpts,
 
 bool Module::isAvailable(const LangOptions &LangOpts, const TargetInfo &Target,
                          Requirement &Req,
-                         UnresolvedHeaderDirective &MissingHeader,
-                         Module *&ShadowingModule) const {
+                         UnresolvedHeaderDirective &MissingHeader) const {
   if (IsAvailable)
     return true;
 
   for (const Module *Current = this; Current; Current = Current->Parent) {
-    if (Current->ShadowingModule) {
-      ShadowingModule = Current->ShadowingModule;
-      return false;
-    }
     for (unsigned I = 0, N = Current->Requirements.size(); I != N; ++I) {
       if (hasFeature(Current->Requirements[I].first, LangOpts, Target) !=
               Current->Requirements[I].second) {
diff --git a/lib/Lex/HeaderSearch.cpp b/lib/Lex/HeaderSearch.cpp
index ec8175470632..6976294a2eaf 100644
--- a/lib/Lex/HeaderSearch.cpp
+++ b/lib/Lex/HeaderSearch.cpp
@@ -1367,8 +1367,7 @@ bool HeaderSearch::loadModuleMapFile(const FileEntry *File, bool IsSystem,
     }
   }
 
-  switch (loadModuleMapFileImpl(File, IsSystem, Dir,
-                                /*IsExplictlyProvided=*/true, ID, Offset)) {
+  switch (loadModuleMapFileImpl(File, IsSystem, Dir, ID, Offset)) {
   case LMM_AlreadyLoaded:
   case LMM_NewlyLoaded:
     return false;
@@ -1379,9 +1378,10 @@ bool HeaderSearch::loadModuleMapFile(const FileEntry *File, bool IsSystem,
   llvm_unreachable("Unknown load module map result");
 }
 
-HeaderSearch::LoadModuleMapResult HeaderSearch::loadModuleMapFileImpl(
-    const FileEntry *File, bool IsSystem, const DirectoryEntry *Dir,
-    bool IsExplicitlyProvided, FileID ID, unsigned *Offset) {
+HeaderSearch::LoadModuleMapResult
+HeaderSearch::loadModuleMapFileImpl(const FileEntry *File, bool IsSystem,
+                                    const DirectoryEntry *Dir, FileID ID,
+                                    unsigned *Offset) {
   assert(File && "expected FileEntry");
 
   // Check whether we've already loaded this module map, and mark it as being
@@ -1390,16 +1390,14 @@ HeaderSearch::LoadModuleMapResult HeaderSearch::loadModuleMapFileImpl(
   if (!AddResult.second)
     return AddResult.first->second ? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
 
-  if (ModMap.parseModuleMapFile(File, IsSystem, Dir, IsExplicitlyProvided, ID,
-                                Offset)) {
+  if (ModMap.parseModuleMapFile(File, IsSystem, Dir, ID, Offset)) {
     LoadedModuleMaps[File] = false;
     return LMM_InvalidModuleMap;
   }
 
   // Try to load a corresponding private module map.
   if (const FileEntry *PMMFile = getPrivateModuleMap(File, FileMgr)) {
-    if (ModMap.parseModuleMapFile(PMMFile, IsSystem, Dir,
-                                  IsExplicitlyProvided)) {
+    if (ModMap.parseModuleMapFile(PMMFile, IsSystem, Dir)) {
       LoadedModuleMaps[File] = false;
       return LMM_InvalidModuleMap;
     }
@@ -1470,8 +1468,8 @@ HeaderSearch::loadModuleMapFile(const DirectoryEntry *Dir, bool IsSystem,
     return KnownDir->second ? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
 
   if (const FileEntry *ModuleMapFile = lookupModuleMapFile(Dir, IsFramework)) {
-    LoadModuleMapResult Result = loadModuleMapFileImpl(
-        ModuleMapFile, IsSystem, Dir, /*IsExplicitlyProvided=*/false);
+    LoadModuleMapResult Result =
+        loadModuleMapFileImpl(ModuleMapFile, IsSystem, Dir);
     // Add Dir explicitly in case ModuleMapFile is in a subdirectory.
     // E.g. Foo.framework/Modules/module.modulemap
     //      ^Dir                  ^ModuleMapFile
diff --git a/lib/Lex/ModuleMap.cpp b/lib/Lex/ModuleMap.cpp
index c2ea64fcd125..b3ac10c5c5ae 100644
--- a/lib/Lex/ModuleMap.cpp
+++ b/lib/Lex/ModuleMap.cpp
@@ -744,13 +744,14 @@ Module *ModuleMap::lookupModuleQualified(StringRef Name, Module *Context) const{
   return Context->findSubmodule(Name);
 }
 
-std::pair<Module *, bool>
-ModuleMap::findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
-                              bool IsExplicit, bool UsesExplicitModuleMapFile) {
+std::pair<Module *, bool> ModuleMap::findOrCreateModule(StringRef Name,
+                                                        Module *Parent,
+                                                        bool IsFramework,
+                                                        bool IsExplicit) {
   // Try to find an existing module with this name.
   if (Module *Sub = lookupModuleQualified(Name, Parent))
     return std::make_pair(Sub, false);
-
+  
   // Create a new module with this name.
   Module *Result = new Module(Name, SourceLocation(), Parent, IsFramework,
                               IsExplicit, NumCreatedModules++);
@@ -758,8 +759,6 @@ ModuleMap::findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
     if (LangOpts.CurrentModule == Name)
       SourceModule = Result;
     Modules[Name] = Result;
-    if (UsesExplicitModuleMapFile)
-      ExplicitlyProvidedModules.insert(Result);
   }
   return std::make_pair(Result, true);
 }
@@ -1000,19 +999,6 @@ Module *ModuleMap::inferFrameworkModule(const DirectoryEntry *FrameworkDir,
   return Result;
 }
 
-Module *ModuleMap::createShadowedModule(StringRef Name, bool IsFramework,
-                                        Module *ShadowingModule) {
-
-  // Create a new module with this name.
-  Module *Result =
-      new Module(Name, SourceLocation(), /*Parent=*/nullptr, IsFramework,
-                 /*IsExplicit=*/false, NumCreatedModules++);
-  Result->ShadowingModule = ShadowingModule;
-  Result->IsAvailable = false;
-
-  return Result;
-}
-
 void ModuleMap::setUmbrellaHeader(Module *Mod, const FileEntry *UmbrellaHeader,
                                   Twine NameAsWritten) {
   Headers[UmbrellaHeader].push_back(KnownHeader(Mod, NormalHeader));
@@ -1130,11 +1116,6 @@ void ModuleMap::excludeHeader(Module *Mod, Module::Header Header) {
   Mod->Headers[Module::HK_Excluded].push_back(std::move(Header));
 }
 
-void ModuleMap::setExplicitlyProvided(Module *Mod) {
-  assert(Modules[Mod->Name] == Mod && "explicitly provided module is shadowed");
-  ExplicitlyProvidedModules.insert(Mod);
-}
-
 const FileEntry *
 ModuleMap::getContainingModuleMapFile(const Module *Module) const {
   if (Module->DefinitionLoc.isInvalid())
@@ -1338,9 +1319,7 @@ namespace clang {
 
     /// \brief Consume the current token and return its location.
     SourceLocation consumeToken();
-
-    bool UsesExplicitModuleMapFile = false;
-
+    
     /// \brief Skip tokens until we reach the a token with the given kind
     /// (or the end of the file).
     void skipUntil(MMToken::TokenKind K);
@@ -1366,19 +1345,20 @@ namespace clang {
     bool parseOptionalAttributes(Attributes &Attrs);
     
   public:
-    explicit ModuleMapParser(Lexer &L, SourceManager &SourceMgr,
-                             const TargetInfo *Target, DiagnosticsEngine &Diags,
-                             ModuleMap &Map, const FileEntry *ModuleMapFile,
-                             const DirectoryEntry *Directory, bool IsSystem,
-                             bool UsesExplicitModuleMapFile)
+    explicit ModuleMapParser(Lexer &L, SourceManager &SourceMgr, 
+                             const TargetInfo *Target,
+                             DiagnosticsEngine &Diags,
+                             ModuleMap &Map,
+                             const FileEntry *ModuleMapFile,
+                             const DirectoryEntry *Directory,
+                             bool IsSystem)
         : L(L), SourceMgr(SourceMgr), Target(Target), Diags(Diags), Map(Map),
           ModuleMapFile(ModuleMapFile), Directory(Directory),
-          IsSystem(IsSystem),
-          UsesExplicitModuleMapFile(UsesExplicitModuleMapFile) {
+          IsSystem(IsSystem) {
       Tok.clear();
       consumeToken();
     }
-
+    
     bool parseModuleMapFile();
 
     bool terminatedByDirective() { return false; }
@@ -1807,7 +1787,6 @@ void ModuleMapParser::parseModuleDecl() {
   SourceLocation LBraceLoc = consumeToken();
   
   // Determine whether this (sub)module has already been defined.
-  Module *ShadowingModule = nullptr;
   if (Module *Existing = Map.lookupModuleQualified(ModuleName, ActiveModule)) {
     // We might see a (re)definition of a module that we already have a
     // definition for in two cases:
@@ -1833,36 +1812,23 @@ void ModuleMapParser::parseModuleDecl() {
       }
       return;
     }
-
-    if (!Existing->Parent &&
-        Map.mayShadowModuleBeingParsed(Existing, UsesExplicitModuleMapFile)) {
-      ShadowingModule = Existing;
-    } else {
-      // This is not a shawdowed module decl, it is an illegal redefinition.
-      Diags.Report(ModuleNameLoc, diag::err_mmap_module_redefinition)
-          << ModuleName;
-      Diags.Report(Existing->DefinitionLoc, diag::note_mmap_prev_definition);
-
-      // Skip the module definition.
-      skipUntil(MMToken::RBrace);
-      if (Tok.is(MMToken::RBrace))
-        consumeToken();
-
-      HadError = true;
-      return;
-    }
+    
+    Diags.Report(ModuleNameLoc, diag::err_mmap_module_redefinition)
+      << ModuleName;
+    Diags.Report(Existing->DefinitionLoc, diag::note_mmap_prev_definition);
+    
+    // Skip the module definition.
+    skipUntil(MMToken::RBrace);
+    if (Tok.is(MMToken::RBrace))
+      consumeToken();
+    
+    HadError = true;
+    return;
   }
 
   // Start defining this module.
-  if (ShadowingModule) {
-    ActiveModule =
-        Map.createShadowedModule(ModuleName, Framework, ShadowingModule);
-  } else {
-    ActiveModule = Map.findOrCreateModule(ModuleName, ActiveModule, Framework,
-                                          Explicit, UsesExplicitModuleMapFile)
-                       .first;
-  }
-
+  ActiveModule = Map.findOrCreateModule(ModuleName, ActiveModule, Framework,
+                                        Explicit).first;
   ActiveModule->DefinitionLoc = ModuleNameLoc;
   if (Attrs.IsSystem || IsSystem)
     ActiveModule->IsSystem = true;
@@ -2038,7 +2004,7 @@ void ModuleMapParser::parseExternModuleDecl() {
         Map.HeaderInfo.getHeaderSearchOpts().ModuleMapFileHomeIsCwd
             ? Directory
             : File->getDir(),
-        false /*IsExplicitlyProvided*/, FileID(), nullptr, ExternLoc);
+        FileID(), nullptr, ExternLoc);
 }
 
 /// Whether to add the requirement \p Feature to the module \p M.
@@ -2845,8 +2811,7 @@ bool ModuleMapParser::parseModuleMapFile() {
 }
 
 bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem,
-                                   const DirectoryEntry *Dir,
-                                   bool IsExplicitlyProvided, FileID ID,
+                                   const DirectoryEntry *Dir, FileID ID,
                                    unsigned *Offset,
                                    SourceLocation ExternModuleLoc) {
   assert(Target && "Missing target information");
@@ -2876,7 +2841,7 @@ bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem,
           Buffer->getBufferEnd());
   SourceLocation Start = L.getSourceLocation();
   ModuleMapParser Parser(L, SourceMgr, Target, Diags, *this, File, Dir,
-                         IsSystem, IsExplicitlyProvided);
+                         IsSystem);
   bool Result = Parser.parseModuleMapFile();
   ParsedModuleMap[File] = Result;
 
@@ -2889,6 +2854,5 @@ bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem,
   // Notify callbacks that we parsed it.
   for (const auto &Cb : Callbacks)
     Cb->moduleMapFileRead(Start, *File, IsSystem);
-
   return Result;
 }
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 77ee1faf283f..ca3e70fd1060 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -1655,18 +1655,12 @@ bool Preprocessor::checkModuleIsAvailable(const LangOptions &LangOpts,
                                           DiagnosticsEngine &Diags, Module *M) {
   Module::Requirement Requirement;
   Module::UnresolvedHeaderDirective MissingHeader;
-  Module *ShadowingModule = nullptr;
-  if (M->isAvailable(LangOpts, TargetInfo, Requirement, MissingHeader,
-                     ShadowingModule))
+  if (M->isAvailable(LangOpts, TargetInfo, Requirement, MissingHeader))
     return false;
 
   if (MissingHeader.FileNameLoc.isValid()) {
     Diags.Report(MissingHeader.FileNameLoc, diag::err_module_header_missing)
         << MissingHeader.IsUmbrella << MissingHeader.FileName;
-  } else if (ShadowingModule) {
-    Diags.Report(M->DefinitionLoc, diag::err_module_shadowed) << M->Name;
-    Diags.Report(ShadowingModule->DefinitionLoc,
-                 diag::note_previous_definition);
   } else {
     // FIXME: Track the location at which the requirement was specified, and
     // use it here.
@@ -2030,15 +2024,6 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
 
   // Determine if we're switching to building a new submodule, and which one.
   if (auto *M = SuggestedModule.getModule()) {
-    if (M->getTopLevelModule()->ShadowingModule) {
-      // We are building a submodule that belongs to a shadowed module. This
-      // means we find header files in the shadowed module.
-      Diag(M->DefinitionLoc, diag::err_module_build_shadowed_submodule)
-        << M->getFullModuleName();
-      Diag(M->getTopLevelModule()->ShadowingModule->DefinitionLoc,
-           diag::note_previous_definition);
-      return;
-    }
     // When building a pch, -fmodule-name tells the compiler to textually
     // include headers in the specified module. We are not building the
     // specified module.
diff --git a/test/Modules/Inputs/shadow/A1/A.h b/test/Modules/Inputs/shadow/A1/A.h
deleted file mode 100644
index f07c681c2aa5..000000000000
--- a/test/Modules/Inputs/shadow/A1/A.h
+++ /dev/null
@@ -1 +0,0 @@
-#define A1_A_h
diff --git a/test/Modules/Inputs/shadow/A1/module.modulemap b/test/Modules/Inputs/shadow/A1/module.modulemap
deleted file mode 100644
index 9439a431b1db..000000000000
--- a/test/Modules/Inputs/shadow/A1/module.modulemap
+++ /dev/null
@@ -1,5 +0,0 @@
-module A {
-  header "A.h"
-}
-
-module A1 {}
diff --git a/test/Modules/Inputs/shadow/A2/A.h b/test/Modules/Inputs/shadow/A2/A.h
deleted file mode 100644
index 9880ed010f56..000000000000
--- a/test/Modules/Inputs/shadow/A2/A.h
+++ /dev/null
@@ -1 +0,0 @@
-#define A2_A_h
diff --git a/test/Modules/Inputs/shadow/A2/module.modulemap b/test/Modules/Inputs/shadow/A2/module.modulemap
deleted file mode 100644
index 935d89bb425e..000000000000
--- a/test/Modules/Inputs/shadow/A2/module.modulemap
+++ /dev/null
@@ -1,5 +0,0 @@
-module A {
-  header "A.h"
-}
-
-module A2 {}
diff --git a/test/Modules/Inputs/shadowed-submodule/A1/Foo.h b/test/Modules/Inputs/shadowed-submodule/A1/Foo.h
deleted file mode 100644
index 57775d1a29dd..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A1/Foo.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <stdarg.h> // expected-error {{could not build module 'A'}}
diff --git a/test/Modules/Inputs/shadowed-submodule/A1/module.modulemap b/test/Modules/Inputs/shadowed-submodule/A1/module.modulemap
deleted file mode 100644
index 7afbc4713617..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A1/module.modulemap
+++ /dev/null
@@ -1,14 +0,0 @@
-module A [system] { // expected-note {{previous definition is here}}
-  module sub {
-    header "sys/A.h"
-  }
-  module sub2 {
-    header "sys/A2.h"
-  }
-  module stdarg {
-    header "stdarg.h"
-    export *
-  }
-}
-
-module A2 {}
diff --git a/test/Modules/Inputs/shadowed-submodule/A1/sys/A.h b/test/Modules/Inputs/shadowed-submodule/A1/sys/A.h
deleted file mode 100644
index 4fc3e8ea9e63..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A1/sys/A.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <sys/A2.h>
diff --git a/test/Modules/Inputs/shadowed-submodule/A1/sys/A2.h b/test/Modules/Inputs/shadowed-submodule/A1/sys/A2.h
deleted file mode 100644
index e9b6a44cfe21..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A1/sys/A2.h
+++ /dev/null
@@ -1 +0,0 @@
-// nothing
diff --git a/test/Modules/Inputs/shadowed-submodule/A2/Foo.h b/test/Modules/Inputs/shadowed-submodule/A2/Foo.h
deleted file mode 100644
index 38ade6d9f505..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A2/Foo.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <stdarg.h>
diff --git a/test/Modules/Inputs/shadowed-submodule/A2/module.modulemap b/test/Modules/Inputs/shadowed-submodule/A2/module.modulemap
deleted file mode 100644
index c4e44b074aa1..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A2/module.modulemap
+++ /dev/null
@@ -1,14 +0,0 @@
-module A [system] {
-  module sub {
-    header "sys/A.h"
-  }
-  module sub2 { // expected-error {{build a shadowed submodule 'A.sub2'}}
-    header "sys/A2.h"
-  }
-  module stdarg {
-    header "stdarg.h"
-    export *
-  }
-}
-
-module A2 {}
diff --git a/test/Modules/Inputs/shadowed-submodule/A2/sys/A.h b/test/Modules/Inputs/shadowed-submodule/A2/sys/A.h
deleted file mode 100644
index 4fc3e8ea9e63..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A2/sys/A.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <sys/A2.h>
diff --git a/test/Modules/Inputs/shadowed-submodule/A2/sys/A2.h b/test/Modules/Inputs/shadowed-submodule/A2/sys/A2.h
deleted file mode 100644
index e9b6a44cfe21..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/A2/sys/A2.h
+++ /dev/null
@@ -1 +0,0 @@
-// nothing
diff --git a/test/Modules/Inputs/shadowed-submodule/Foo/module.modulemap b/test/Modules/Inputs/shadowed-submodule/Foo/module.modulemap
deleted file mode 100644
index 11db9cb05da2..000000000000
--- a/test/Modules/Inputs/shadowed-submodule/Foo/module.modulemap
+++ /dev/null
@@ -1,3 +0,0 @@
-module Foo {
-  header "../A1/Foo.h"
-}
diff --git a/test/Modules/shadow.m b/test/Modules/shadow.m
deleted file mode 100644
index 44320af2b0c6..000000000000
--- a/test/Modules/shadow.m
+++ /dev/null
@@ -1,21 +0,0 @@
-// RUN: rm -rf %t
-// RUN: not %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I %S/Inputs/shadow/A1 -I %S/Inputs/shadow/A2 %s -fsyntax-only 2>&1 | FileCheck %s -check-prefix=REDEFINITION
-// RUN: not %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fmodule-map-file=%S/Inputs/shadow/A1/module.modulemap -fmodule-map-file=%S/Inputs/shadow/A2/module.modulemap %s -fsyntax-only 2>&1 | FileCheck %s -check-prefix=REDEFINITION
-// REDEFINITION: error: redefinition of module 'A'
-// REDEFINITION: note: previously defined
-
-// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -fmodule-map-file=%S/Inputs/shadow/A1/module.modulemap -I %S/Inputs/shadow %s -verify
-
-@import A1;
-@import A2;
-@import A;
-
-#import "A2/A.h" // expected-note {{implicitly imported}}
-// expected-error@A2/module.modulemap:1 {{import of shadowed module 'A'}}
-// expected-note@A1/module.modulemap:1 {{previous definition}}
-
-#if defined(A2_A_h)
-#error got the wrong definition of module A
-#elif !defined(A1_A_h)
-#error missing definition from A1
-#endif
diff --git a/test/Modules/shadowed-submodule.m b/test/Modules/shadowed-submodule.m
deleted file mode 100644
index c9c77bd13a1c..000000000000
--- a/test/Modules/shadowed-submodule.m
+++ /dev/null
@@ -1,5 +0,0 @@
-// RUN: rm -rf %t
-// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I %S/Inputs/shadowed-submodule/Foo -I %S/Inputs/shadowed-submodule/A2 %s -verify
-
-@import Foo; // expected-error {{module 'A' was built in directory}}
-             // expected-note@shadowed-submodule.m:4 {{imported by module 'Foo'}}