[NFC] [C++20] [Modules] Refactor Module::getGlobalModuleFragment and Module::getPrivateModuleFragment

The original implementation of `Module::getGlobalModuleFragment` and
`Module::getPrivateModuleFragment` tried to find the global module
fragment and the private module fragment by comparing strings, which
smells bad. This patch tries to improve this.

1 files changed, 22 insertions, 0 deletions

diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index 4ffdb6a..4e6fbfc 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -370,6 +370,28 @@ Module *Module::findOrInferSubmodule(StringRef Name) {
   return Result;
 }
 
+Module *Module::getGlobalModuleFragment() const {
+  assert(isNamedModuleUnit() && "We should only query the global module "
+                                "fragment from the C++ 20 Named modules");
+
+  for (auto *SubModule : SubModules)
+    if (SubModule->isExplicitGlobalModule())
+      return SubModule;
+
+  return nullptr;
+}
+
+Module *Module::getPrivateModuleFragment() const {
+  assert(isNamedModuleUnit() && "We should only query the private module "
+                                "fragment from the C++ 20 Named modules");
+
+  for (auto *SubModule : SubModules)
+    if (SubModule->isPrivateModule())
+      return SubModule;
+
+  return nullptr;
+}
+
 void Module::getExportedModules(SmallVectorImpl<Module *> &Exported) const {
   // All non-explicit submodules are exported.
   for (std::vector<Module *>::const_iterator I = SubModules.begin(),