[clang][ASTImporter] Add import API for 'const Type *' (NFC).

[balazske]

Summary

There was only an Import function for QualType but not for Type.
For correct import of some AST nodes where not QualType is used
an import of Type * is needed. (It is the case with
FieldDecl::getCapturedVLAType.)

[teemperor]

LGTM, thanks!

[shafik]

Can we add a test for the getCapturedVLAType case?

[balazske]

In D98951#2637807, @shafik wrote:

Can we add a test for the getCapturedVLAType case?

The test is added here: D99062

[martong]

LG! Thanks!

[shafik]

Thank you for adding the test!

clang/include/clang/AST/ASTImporter.h

LLVM_NODISCARD llvm::Error importInto(ImportT &To, const ImportT &From) {
       return ToOrErr.takeError();
     }
 
     /// Import cleanup objects owned by ExprWithCleanup.
     llvm::Expected<ExprWithCleanups::CleanupObject>
     Import(ExprWithCleanups::CleanupObject From);
 
     /// Import the given type from the "from" context into the "to"
+    /// context.
+    ///
+    /// \returns The equivalent type in the "to" context, or the import error.
+    llvm::Expected<const Type *> Import(const Type *FromT);
+
+    /// Import the given qualified type from the "from" context into the "to"
     /// context. A null type is imported as a null type (no error).
     ///
     /// \returns The equivalent type in the "to" context, or the import error.
     llvm::Expected<QualType> Import(QualType FromT);
 
     /// Import the given type source information from the
     /// "from" context into the "to" context.
     ///

clang/lib/AST/ASTImporter.cpp

if (Expected<Expr *> R = Import(CLE))
       return ExprWithCleanups::CleanupObject(cast<CompoundLiteralExpr>(*R));
   }
 
   // FIXME: Handle BlockDecl when we implement importing BlockExpr in
   //        ASTNodeImporter.
   return make_error<ImportError>(ImportError::UnsupportedConstruct);
 }
 
-Expected<QualType> ASTImporter::Import(QualType FromT) {
-  if (FromT.isNull())
-    return QualType{};
-
-  const Type *FromTy = FromT.getTypePtr();
+Expected<const Type *> ASTImporter::Import(const Type *FromT) {
+  if (!FromT)
+    return FromT;
 
   // Check whether we've already imported this type.
-  llvm::DenseMap<const Type *, const Type *>::iterator Pos
-    = ImportedTypes.find(FromTy);
+  llvm::DenseMap<const Type *, const Type *>::iterator Pos =
+      ImportedTypes.find(FromT);
   if (Pos != ImportedTypes.end())
-    return ToContext.getQualifiedType(Pos->second, FromT.getLocalQualifiers());
+    return Pos->second;
 
   // Import the type
   ASTNodeImporter Importer(*this);
-  ExpectedType ToTOrErr = Importer.Visit(FromTy);
+  ExpectedType ToTOrErr = Importer.Visit(FromT);
   if (!ToTOrErr)
     return ToTOrErr.takeError();
 
   // Record the imported type.
-  ImportedTypes[FromTy] = (*ToTOrErr).getTypePtr();
+  ImportedTypes[FromT] = ToTOrErr->getTypePtr();
+
+  return ToTOrErr->getTypePtr();
+}
+
+Expected<QualType> ASTImporter::Import(QualType FromT) {
+  if (FromT.isNull())
+    return QualType{};
+
+  Expected<const Type *> ToTyOrErr = Import(FromT.getTypePtr());
+  if (!ToTyOrErr)
+    return ToTyOrErr.takeError();
 
-  return ToContext.getQualifiedType(*ToTOrErr, FromT.getLocalQualifiers());
+  return ToContext.getQualifiedType(*ToTyOrErr, FromT.getLocalQualifiers());
 }
 
 Expected<TypeSourceInfo *> ASTImporter::Import(TypeSourceInfo *FromTSI) {
   if (!FromTSI)
     return FromTSI;
 
   // FIXME: For now we just create a "trivial" type source info based
   // on the type and a single location. Implement a real version of this.