[C++20] [Modules] Allow export from language linkage

Close https://github.com/llvm/llvm-project/issues/71347

Previously I misread the concept of module purview. I thought if a
declaration attached to a unnamed module, it can't be part of the module
purview. But after the issue report, I recognized that module purview is
more of a concept about locations instead of semantics.

Concretely, the things in the language linkage after module declarations
can be exported.

This patch refactors `Module::isModulePurview()` and introduces some
possible code cleanups.

1 files changed, 6 insertions, 6 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index e4f3cdd..00e13c9 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -881,17 +881,17 @@ Module *ModuleMap::createGlobalModuleFragmentForModuleUnit(SourceLocation Loc,
   return Result;
 }
 
-Module *ModuleMap::createImplicitGlobalModuleFragmentForModuleUnit(
-    SourceLocation Loc, bool IsExported, Module *Parent) {
+Module *
+ModuleMap::createImplicitGlobalModuleFragmentForModuleUnit(SourceLocation Loc,
+                                                           Module *Parent) {
   assert(Parent && "We should only create an implicit global module fragment "
                    "in a module purview");
   // Note: Here the `IsExplicit` parameter refers to the semantics in clang
   // modules. All the non-explicit submodules in clang modules will be exported
   // too. Here we simplify the implementation by using the concept.
-  auto *Result = new Module(IsExported ? "<exported implicit global>"
-                                       : "<implicit global>",
-                            Loc, Parent, /*IsFramework*/ false,
-                            /*IsExplicit*/ !IsExported, NumCreatedModules++);
+  auto *Result =
+      new Module("<implicit global>", Loc, Parent, /*IsFramework=*/false,
+                 /*IsExplicit=*/false, NumCreatedModules++);
   Result->Kind = Module::ImplicitGlobalModuleFragment;
   return Result;
 }