[NFC] Remove unused codes after 4a7be42

There are still some unused codes remained after 4a7be42. And this
patch tries to remove them.

Author: ChuanqiXu9

clang/include/clang/Basic/DiagnosticFrontendKinds.td

@@ -213,9 +213,6 @@ def err_module_build_requires_fmodules : Error<
   "module compilation requires '-fmodules'">;
 def err_module_interface_requires_cpp_modules : Error<
   "module interface compilation requires '-std=c++20' or '-fmodules-ts'">;
-def err_header_module_requires_modules : Error<
-  "header module compilation requires '-fmodules', '-std=c++20', or "
-  "'-fmodules-ts'">;
 def warn_module_config_mismatch : Warning<
   "module file %0 cannot be loaded due to a configuration mismatch with the current "
   "compilation">, InGroup<DiagGroup<"module-file-config-mismatch">>, DefaultError;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -11095,7 +11095,7 @@ def err_invalid_type_for_program_scope_var : Error<
 let CategoryName = "Modules Issue" in {
 def err_module_decl_in_module_map_module : Error<
   "'module' declaration found while building module from module map">;
-def err_module_decl_in_header_module : Error<
+def err_module_decl_in_header_unit : Error<
   "'module' declaration found while building header unit">;
 def err_module_interface_implementation_mismatch : Error<
   "missing 'export' specifier in module declaration while "

clang/include/clang/Basic/LangOptions.h

@@ -110,9 +110,6 @@ class LangOptions : public LangOptionsBase {
     /// Compiling a module from a module map.
     CMK_ModuleMap,
 
-    /// Compiling a module from a list of header files.
-    CMK_HeaderModule,
-
     /// Compiling a module header unit.
     CMK_HeaderUnit,
 

clang/include/clang/Driver/Action.h

@@ -58,7 +58,6 @@ class Action {
     OffloadClass,
     PreprocessJobClass,
     PrecompileJobClass,
-    HeaderModulePrecompileJobClass,
     ExtractAPIJobClass,
     AnalyzeJobClass,
     MigrateJobClass,
@@ -431,8 +430,7 @@ class PrecompileJobAction : public JobAction {
   PrecompileJobAction(Action *Input, types::ID OutputType);
 
   static bool classof(const Action *A) {
-    return A->getKind() == PrecompileJobClass ||
-           A->getKind() == HeaderModulePrecompileJobClass;
+    return A->getKind() == PrecompileJobClass;
   }
 };
 

clang/lib/Driver/ToolChain.cpp

@@ -395,7 +395,6 @@ Tool *ToolChain::getTool(Action::ActionClass AC) const {
 
   case Action::CompileJobClass:
   case Action::PrecompileJobClass:
-  case Action::HeaderModulePrecompileJobClass:
   case Action::PreprocessJobClass:
   case Action::ExtractAPIJobClass:
   case Action::AnalyzeJobClass:

clang/lib/Driver/ToolChains/Clang.cpp

@@ -4558,11 +4558,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   InputInfo ExtractAPIPlaceholderInput(Inputs[0].getType(), "extract-api",
                                        "extract-api");
 
-  const InputInfo &Input = [&]() -> const InputInfo & {
-    if (IsExtractAPI)
-      return ExtractAPIPlaceholderInput;
-    return Inputs[0];
-  }();
+  const InputInfo &Input =
+      IsExtractAPI ? ExtractAPIPlaceholderInput : Inputs[0];
 
   InputInfoList ExtractAPIInputs;
   InputInfoList HostOffloadingInputs;

clang/lib/Sema/SemaModule.cpp

@@ -225,9 +225,8 @@ Sema::ActOnModuleDecl(SourceLocation StartLoc, SourceLocation ModuleLoc,
     Diag(ModuleLoc, diag::err_module_decl_in_module_map_module);
     return nullptr;
 
-  case LangOptions::CMK_HeaderModule:
   case LangOptions::CMK_HeaderUnit:
-    Diag(ModuleLoc, diag::err_module_decl_in_header_module);
+    Diag(ModuleLoc, diag::err_module_decl_in_header_unit);
     return nullptr;
   }