[NFC] [Modules] Introduce 'DeclBase::isInNamedModule' interface

This patch introduces DeclBase::isInNamedModule API to ease the use
of modules slightly.

Author: ChuanqiXu9

clang/include/clang/AST/DeclBase.h

@@ -673,6 +673,9 @@ class alignas(8) Decl {
   /// Whether this declaration comes from explicit global module.
   bool isFromExplicitGlobalModule() const;
 
+  /// Whether this declaration comes from a named module.
+  bool isInNamedModule() const;
+
   /// Return true if this declaration has an attribute which acts as
   /// definition of the entity, such as 'alias' or 'ifunc'.
   bool hasDefiningAttr() const;

clang/lib/AST/Decl.cpp

@@ -1181,13 +1181,6 @@ Linkage NamedDecl::getLinkageInternal() const {
       .getLinkage();
 }
 
-/// Determine whether D is attached to a named module.
-static bool isInNamedModule(const NamedDecl *D) {
-  if (auto *M = D->getOwningModule())
-    return M->isNamedModule();
-  return false;
-}
-
 static bool isExportedFromModuleInterfaceUnit(const NamedDecl *D) {
   // FIXME: Handle isModulePrivate.
   switch (D->getModuleOwnershipKind()) {
@@ -1197,7 +1190,7 @@ static bool isExportedFromModuleInterfaceUnit(const NamedDecl *D) {
     return false;
   case Decl::ModuleOwnershipKind::Visible:
   case Decl::ModuleOwnershipKind::VisibleWhenImported:
-    return isInNamedModule(D);
+    return D->isInNamedModule();
   }
   llvm_unreachable("unexpected module ownership kind");
 }
@@ -1215,7 +1208,7 @@ Linkage NamedDecl::getFormalLinkage() const {
   // [basic.namespace.general]/p2
   //   A namespace is never attached to a named module and never has a name with
   //   module linkage.
-  if (isInNamedModule(this) && InternalLinkage == Linkage::External &&
+  if (isInNamedModule() && InternalLinkage == Linkage::External &&
       !isExportedFromModuleInterfaceUnit(
           cast<NamedDecl>(this->getCanonicalDecl())) &&
       !isa<NamespaceDecl>(this))

clang/lib/AST/DeclBase.cpp

@@ -1145,6 +1145,10 @@ bool Decl::isFromExplicitGlobalModule() const {
   return getOwningModule() && getOwningModule()->isExplicitGlobalModule();
 }
 
+bool Decl::isInNamedModule() const {
+  return getOwningModule() && getOwningModule()->isNamedModule();
+}
+
 static Decl::Kind getKind(const Decl *D) { return D->getKind(); }
 static Decl::Kind getKind(const DeclContext *DC) { return DC->getDeclKind(); }
 

clang/lib/Sema/SemaDecl.cpp

@@ -10094,7 +10094,7 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     // check at the end of the TU (or when the PMF starts) to see that we
     // have a definition at that point.
     if (isInline && !D.isFunctionDefinition() && getLangOpts().CPlusPlus20 &&
-        NewFD->hasOwningModule() && NewFD->getOwningModule()->isNamedModule()) {
+        NewFD->isInNamedModule()) {
       PendingInlineFuncDecls.insert(NewFD);
     }
   }