Revert "Fix regression in behavior of clang -x c++-header -fmodule-name=XXX"

This reverts commit r345803 and r345915 (a follow-up fix to r345803).

Reason: r345803 blocks our internal integrate because of the new
warnings showing up in too many places. The fix is actually correct,
we will reland it after figuring out how to integrate properly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@345963 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Driver/ToolChains/Clang.cpp

@@ -3250,15 +3250,18 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   bool IsCuda = JA.isOffloading(Action::OFK_Cuda);
   bool IsHIP = JA.isOffloading(Action::OFK_HIP);
   bool IsOpenMPDevice = JA.isDeviceOffloading(Action::OFK_OpenMP);
+  bool IsModulePrecompile =
+      isa<PrecompileJobAction>(JA) && JA.getType() == types::TY_ModuleFile;
   bool IsHeaderModulePrecompile = isa<HeaderModulePrecompileJobAction>(JA);
 
   // A header module compilation doesn't have a main input file, so invent a
   // fake one as a placeholder.
+  // FIXME: Pick the language based on the header file language.
   const char *ModuleName = [&]{
     auto *ModuleNameArg = Args.getLastArg(options::OPT_fmodule_name_EQ);
     return ModuleNameArg ? ModuleNameArg->getValue() : "";
   }();
-  InputInfo HeaderModuleInput(Inputs[0].getType(), ModuleName, ModuleName);
+  InputInfo HeaderModuleInput(types::TY_CXXModule, ModuleName, ModuleName);
 
   const InputInfo &Input =
       IsHeaderModulePrecompile ? HeaderModuleInput : Inputs[0];
@@ -3269,9 +3272,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   for (const InputInfo &I : Inputs) {
     if (&I == &Input) {
       // This is the primary input.
-    } else if (IsHeaderModulePrecompile &&
+    } else if (IsModulePrecompile &&
                types::getPrecompiledType(I.getType()) == types::TY_PCH) {
-      types::ID Expected = HeaderModuleInput.getType();
+      types::ID Expected =
+          types::lookupHeaderTypeForSourceType(Inputs[0].getType());
       if (I.getType() != Expected) {
         D.Diag(diag::err_drv_module_header_wrong_kind)
             << I.getFilename() << types::getTypeName(I.getType())

lib/Frontend/CompilerInstance.cpp

@@ -372,9 +372,6 @@ static void InitializeFileRemapping(DiagnosticsEngine &Diags,
 void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
   const PreprocessorOptions &PPOpts = getPreprocessorOpts();
 
-  // The module manager holds a reference to the old preprocessor (if any).
-  ModuleManager.reset();
-
   // Create a PTH manager if we are using some form of a token cache.
   PTHManager *PTHMgr = nullptr;
   if (!PPOpts.TokenCache.empty())

lib/Lex/ModuleMap.cpp

@@ -523,7 +523,7 @@ void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
 
   // At this point, only non-modular includes remain.
 
-  if (RequestingModule && LangOpts.ModulesStrictDeclUse) {
+  if (LangOpts.ModulesStrictDeclUse) {
     Diags.Report(FilenameLoc, diag::err_undeclared_use_of_module)
         << RequestingModule->getTopLevelModule()->Name << Filename;
   } else if (RequestingModule && RequestingModuleIsModuleInterface &&

test/Driver/header-module.cpp

@@ -7,18 +7,7 @@
 // CHECK-PRECOMPILE-SAME: -fno-implicit-modules
 // CHECK-PRECOMPILE-SAME: -fmodule-name=foobar
 // CHECK-PRECOMPILE-SAME: -o {{.*}}.pcm
-// CHECK-PRECOMPILE-SAME: -x c++-header
+// CHECK-PRECOMPILE-SAME: -x c++
 // CHECK-PRECOMPILE-SAME: header1.h
 // CHECK-PRECOMPILE-SAME: header2.h
 // CHECK-PRECOMPILE-SAME: header3.h
-//
-// RUN: %clang -fmodules-ts -fmodule-name=foobar -x c++-header -fsyntax-only %S/Inputs/header1.h %S/Inputs/header2.h %S/Inputs/header3.h -v 2>&1 | FileCheck %s --check-prefix=CHECK-SYNTAX-ONLY
-// CHECK-SYNTAX-ONLY: -cc1 {{.*}} -fsyntax-only
-// CHECK-SYNTAX-ONLY-SAME: -fmodules-ts
-// CHECK-SYNTAX-ONLY-SAME: -fno-implicit-modules
-// CHECK-SYNTAX-ONLY-SAME: -fmodule-name=foobar
-// CHECK-SYNTAX-ONLY-NOT: -o{{ }}
-// CHECK-SYNTAX-ONLY-SAME: -x c++-header
-// CHECK-SYNTAX-ONLY-SAME: header1.h
-// CHECK-SYNTAX-ONLY-SAME: header2.h
-// CHECK-SYNTAX-ONLY-SAME: header3.h

test/Modules/strict-decluse-headers.cpp

@@ -1,17 +0,0 @@
-// RUN: rm -rf %t
-// RUN: mkdir %t
-// RUN: touch %t/foo.h
-// RUN: echo '#include "foo.h"' > %t/bar.h
-// RUN: touch %t/baz.h
-// RUN: echo 'module X { header "bar.h" header "baz.h" }' > %t/map
-//
-// RUN: not %clang_cc1 -fsyntax-only -fmodules -fmodule-map-file=%t/map -I%t -fmodules-strict-decluse -fmodule-name=X -x c++ %t/bar.h %t/baz.h 2>&1 | FileCheck %s
-// RUN: not %clang_cc1 -fsyntax-only -fmodules -fmodule-map-file=%t/map -I%t -fmodules-strict-decluse -fmodule-name=X -x c++ %t/baz.h %t/bar.h 2>&1 | FileCheck %s
-//
-// Don't crash on this: (FIXME: we should produce an error that the specified module name is not known)
-// RUN: %clang_cc1 -fsyntax-only -fmodules -I%t -fmodules-strict-decluse -fmodule-name=X -x c++ %t/baz.h %t/bar.h
-//
-// Don't crash on this: (FIXME: we should produce an error that the specified file is not part of the specified module)
-// RUN: %clang_cc1 -fsyntax-only -fmodules -fmodule-map-file=%t/map -I%t -fmodules-strict-decluse -fmodule-name=X -x c++ %t/foo.h
-//
-// CHECK: module X does not depend on a module exporting 'foo.h'