[ASTImporter] Supporting CXXOperatorCallExpr, SizeOfPackExpr, DependentTemplateSpecializationType, DependentSizedArray, CXXTypeidExpr importing.

[xazax.hun]

Summary

Also fix a problem with CXXTemporaryObjectExpr.

Some of the changes based on https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/AST/ASTImporter.cpp

[a.sidorin]

Hello Peter,

Thank you for the patch! It is almost LGTM, just a few minor questions inline.
Am I understand correctly that it is partially based on https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/AST/ASTImporter.cpp?
Also, FYI: you can use ASTMerge and clang-import-test facilities for testing. ASTMatchers are completely fine, but usage of imported AST samples as Sema lookup source can uncover some subtle issues in the built AST.

lib/AST/ASTImporter.cpp

522

Redundant newline? (Same below).

5826

This can be merged with VisitCallExpr to avoid code duplication.

[xazax.hun]

• Address review comments.

[xazax.hun]

In D42335#983878, @a.sidorin wrote:

Hello Peter,

Thank you for the patch! It is almost LGTM, just a few minor questions inline.
Am I understand correctly that it is partially based on https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/AST/ASTImporter.cpp?
Also, FYI: you can use ASTMerge and clang-import-test facilities for testing. ASTMatchers are completely fine, but usage of imported AST samples as Sema lookup source can uncover some subtle issues in the built AST.

Yeah that is right. One reason I prefer matcher based tests because they tend to be more lightweight, but I think you are right, it is not a bad idea to utilize other tools as well.

[xazax.hun]

• Added import for CXXTypeidExpr. What is the best way to test this? <typeinfo> header is required for using the typeid operator, but relying on the presence of an STL library in tests is usually considered as a bad practice. Should we mock a typeinfo implementation just for this purpose?

[xazax.hun]

• Added test for CXXTypeIdExpr import.

[a.sidorin]

lib/AST/ASTImporter.cpp

6206

As I see from usage of getTypeOperandSourceInfo(), it cannot return nullptr. getExprOperand() is used unchecked sometimes too, but not everywhere.

unittests/AST/ASTImporterTest.cpp

653

This will find only the first typeid(). How about something like this:

void declToImport() {"
             "  int x;"
             " auto a = typeid(int), b = typeid(x);"
             "}",
             Lang_CXX, "", Lang_CXX, Verifier,
             functionDecl(has(varDecl(hasName("a"), hasInitializer(cxxTypeidExpr())),
                                      has(varDecl(hasName("b"), hasInitializer(cxxTypeidExpr())));

?

[xazax.hun]

• Address review comments.

[a.sidorin]

LGTM, thank you!

lib/AST/ASTImporter.cpp

public:
     QualType VisitPointerType(const PointerType *T);
     QualType VisitBlockPointerType(const BlockPointerType *T);
     QualType VisitLValueReferenceType(const LValueReferenceType *T);
     QualType VisitRValueReferenceType(const RValueReferenceType *T);
     QualType VisitMemberPointerType(const MemberPointerType *T);
     QualType VisitConstantArrayType(const ConstantArrayType *T);
     QualType VisitIncompleteArrayType(const IncompleteArrayType *T);
     QualType VisitVariableArrayType(const VariableArrayType *T);
-    // FIXME: DependentSizedArrayType
+    QualType VisitDependentSizedArrayType(const DependentSizedArrayType *T);
     // FIXME: DependentSizedExtVectorType
     QualType VisitVectorType(const VectorType *T);
     QualType VisitExtVectorType(const ExtVectorType *T);
     QualType VisitFunctionNoProtoType(const FunctionNoProtoType *T);
     QualType VisitFunctionProtoType(const FunctionProtoType *T);
     QualType VisitUnresolvedUsingType(const UnresolvedUsingType *T);
     QualType VisitParenType(const ParenType *T);
     QualType VisitTypedefType(const TypedefType *T);
public:
     QualType VisitEnumType(const EnumType *T);
     QualType VisitAttributedType(const AttributedType *T);
     QualType VisitTemplateTypeParmType(const TemplateTypeParmType *T);
     QualType VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T);
     QualType VisitTemplateSpecializationType(const TemplateSpecializationType *T);
     QualType VisitElaboratedType(const ElaboratedType *T);
     // FIXME: DependentNameType
     QualType VisitPackExpansionType(const PackExpansionType *T);
-    // FIXME: DependentTemplateSpecializationType
+    QualType VisitDependentTemplateSpecializationType(
+        const DependentTemplateSpecializationType *T);
     QualType VisitObjCInterfaceType(const ObjCInterfaceType *T);
     QualType VisitObjCObjectType(const ObjCObjectType *T);
     QualType VisitObjCObjectPointerType(const ObjCObjectPointerType *T);
                             
     // Importing declarations                            
     bool ImportDeclParts(NamedDecl *D, DeclContext *&DC, 
                          DeclContext *&LexicalDC, DeclarationName &Name, 
                          NamedDecl *&ToD, SourceLocation &Loc);
public:
     Expr *VisitCXXThrowExpr(CXXThrowExpr *E);
     Expr *VisitCXXNoexceptExpr(CXXNoexceptExpr *E);
     Expr *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E);
     Expr *VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
     Expr *VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
     Expr *VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *CE);
     Expr *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
     Expr *VisitPackExpansionExpr(PackExpansionExpr *E);
+    Expr *VisitSizeOfPackExpr(SizeOfPackExpr *E);
     Expr *VisitCXXNewExpr(CXXNewExpr *CE);
     Expr *VisitCXXDeleteExpr(CXXDeleteExpr *E);
     Expr *VisitCXXConstructExpr(CXXConstructExpr *E);
     Expr *VisitCXXMemberCallExpr(CXXMemberCallExpr *E);
     Expr *VisitCXXDependentScopeMemberExpr(CXXDependentScopeMemberExpr *E);
     Expr *VisitCXXUnresolvedConstructExpr(CXXUnresolvedConstructExpr *CE);
     Expr *VisitUnresolvedLookupExpr(UnresolvedLookupExpr *E);
     Expr *VisitExprWithCleanups(ExprWithCleanups *EWC);
QualType ASTNodeImporter::VisitVariableArrayType(const VariableArrayType *T) {
   
   SourceRange Brackets = Importer.Import(T->getBracketsRange());
   return Importer.getToContext().getVariableArrayType(ToElementType, Size,
                                                       T->getSizeModifier(),
                                                 T->getIndexTypeCVRQualifiers(),
                                                       Brackets);
 }
 
+QualType ASTNodeImporter::VisitDependentSizedArrayType(
+    const DependentSizedArrayType *T) {
+  QualType ToElementType = Importer.Import(T->getElementType());
+  if (ToElementType.isNull())
+    return QualType();
+
+  // SizeExpr may be null if size is not specified directly.
+  // For example, 'int a[]'.
+  Expr *Size = Importer.Import(T->getSizeExpr());
+  if (!Size && T->getSizeExpr())
+    return QualType();
+
+  SourceRange Brackets = Importer.Import(T->getBracketsRange());
+  return Importer.getToContext().getDependentSizedArrayType(
+      ToElementType, Size, T->getSizeModifier(), T->getIndexTypeCVRQualifiers(),
+      Brackets);
+}
+
 QualType ASTNodeImporter::VisitVectorType(const VectorType *T) {
   QualType ToElementType = Importer.Import(T->getElementType());
   if (ToElementType.isNull())
     return QualType();
   
   return Importer.getToContext().getVectorType(ToElementType, 
                                                T->getNumElements(),
                                                T->getVectorKind());
QualType ASTNodeImporter::VisitPackExpansionType(const PackExpansionType *T) {
   QualType Pattern = Importer.Import(T->getPattern());
   if (Pattern.isNull())
     return QualType();
 
   return Importer.getToContext().getPackExpansionType(Pattern,
                                                       T->getNumExpansions());
 }
 
+QualType ASTNodeImporter::VisitDependentTemplateSpecializationType(
+    const DependentTemplateSpecializationType *T) {
+  NestedNameSpecifier *Qualifier = Importer.Import(T->getQualifier());
+  if (!Qualifier && T->getQualifier())
+    return QualType();
+
+  IdentifierInfo *Name = Importer.Import(T->getIdentifier());
+  if (!Name && T->getIdentifier())
+    return QualType();
+
+  SmallVector<TemplateArgument, 2> ToPack;
+  ToPack.reserve(T->getNumArgs());
+  if (ImportTemplateArguments(T->getArgs(), T->getNumArgs(), ToPack))
+    return QualType();
+
+  return Importer.getToContext().getDependentTemplateSpecializationType(
+        T->getKeyword(), Qualifier, Name, ToPack);
+}
+
 QualType ASTNodeImporter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
   ObjCInterfaceDecl *Class
     = dyn_cast_or_null<ObjCInterfaceDecl>(Importer.Import(T->getDecl()));
   if (!Class)
     return QualType();
 
   return Importer.getToContext().getObjCInterfaceType(Class);
 }
Expr *ASTNodeImporter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
   return CXXBindTemporaryExpr::Create(ToCtx, Temp, SubExpr);
 }
 
 Expr *ASTNodeImporter::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *CE) {
   QualType T = Importer.Import(CE->getType());
   if (T.isNull())
     return nullptr;
 
+
+  TypeSourceInfo *TInfo = Importer.Import(CE->getTypeSourceInfo());
+  if (!TInfo)
+    return nullptr;
+
   SmallVector<Expr *, 8> Args(CE->getNumArgs());
   if (ImportContainerChecked(CE->arguments(), Args))
     return nullptr;
 
   auto *Ctor = cast_or_null<CXXConstructorDecl>(
         Importer.Import(CE->getConstructor()));
   if (!Ctor)
     return nullptr;
 
-  return CXXTemporaryObjectExpr::Create(
-        Importer.getToContext(), T,
-        Importer.Import(CE->getLocStart()),
-        Ctor,
-        CE->isElidable(),
-        Args,
-        CE->hadMultipleCandidates(),
-        CE->isListInitialization(),
-        CE->isStdInitListInitialization(),
-        CE->requiresZeroInitialization(),
-        CE->getConstructionKind(),
-        Importer.Import(CE->getParenOrBraceRange()));
+  return new (Importer.getToContext()) CXXTemporaryObjectExpr(
+      Importer.getToContext(), Ctor, T, TInfo, Args,
+      Importer.Import(CE->getParenOrBraceRange()), CE->hadMultipleCandidates(),
+      CE->isListInitialization(), CE->isStdInitListInitialization(),
+      CE->requiresZeroInitialization());
 }
 
 Expr *
 ASTNodeImporter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) {
   QualType T = Importer.Import(E->getType());
   if (T.isNull())
     return nullptr;
 
Expr *ASTNodeImporter::VisitPackExpansionExpr(PackExpansionExpr *E) {
   if (!Pattern)
     return nullptr;
 
   return new (Importer.getToContext()) PackExpansionExpr(
         T, Pattern, Importer.Import(E->getEllipsisLoc()),
         E->getNumExpansions());
 }
 
+Expr *ASTNodeImporter::VisitSizeOfPackExpr(SizeOfPackExpr *E) {
+  auto *Pack = cast_or_null<NamedDecl>(Importer.Import(E->getPack()));
+  if (!Pack)
+    return nullptr;
+
+  Optional<unsigned> Length;
+
+  if (!E->isValueDependent())
+    Length = E->getPackLength();
+
+  SmallVector<TemplateArgument, 8> PartialArguments;
+  if (E->isPartiallySubstituted()) {
+    if (ImportTemplateArguments(E->getPartialArguments().data(),
+                                E->getPartialArguments().size(),
+                                PartialArguments))
+      return nullptr;
+  }
+
+  return SizeOfPackExpr::Create(
+      Importer.getToContext(), Importer.Import(E->getOperatorLoc()), Pack,
+      Importer.Import(E->getPackLoc()), Importer.Import(E->getRParenLoc()),
+      Length, PartialArguments);
+}
+
+
 Expr *ASTNodeImporter::VisitCXXNewExpr(CXXNewExpr *CE) {
   QualType T = Importer.Import(CE->getType());
   if (T.isNull())
     return nullptr;
 
   SmallVector<Expr *, 4> PlacementArgs(CE->getNumPlacementArgs());
   if (ImportContainerChecked(CE->placement_arguments(), PlacementArgs))
     return nullptr;
Expr *ASTNodeImporter::VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
   if (ImportContainerChecked(E->arguments(), ToArgs))
     return nullptr;
 
   return new (Importer.getToContext()) CXXMemberCallExpr(
         Importer.getToContext(), ToFn, ToArgs, T, E->getValueKind(),
         Importer.Import(E->getRParenLoc()));
 }
 
 Expr *ASTNodeImporter::VisitCXXThisExpr(CXXThisExpr *E) {
   QualType T = Importer.Import(E->getType());
   if (T.isNull())
     return nullptr;
   
   return new (Importer.getToContext())
   CXXThisExpr(Importer.Import(E->getLocation()), T, E->isImplicit());
 }
 
Expr *ASTNodeImporter::VisitCallExpr(CallExpr *E) {
   if (T.isNull())
     return nullptr;
 
   Expr *ToCallee = Importer.Import(E->getCallee());
   if (!ToCallee && E->getCallee())
     return nullptr;
 
   unsigned NumArgs = E->getNumArgs();
-
   llvm::SmallVector<Expr *, 2> ToArgs(NumArgs);
-
-  for (unsigned ai = 0, ae = NumArgs; ai != ae; ++ai) {
-    Expr *FromArg = E->getArg(ai);
-    Expr *ToArg = Importer.Import(FromArg);
-    if (!ToArg)
-      return nullptr;
-    ToArgs[ai] = ToArg;
-  }
+  if (ImportContainerChecked(E->arguments(), ToArgs))
 
   Expr **ToArgs_Copied = new (Importer.getToContext()) 
     Expr*[NumArgs];
 
   for (unsigned ai = 0, ae = NumArgs; ai != ae; ++ai)
     ToArgs_Copied[ai] = ToArgs[ai];
 
+  if (const auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
+    return new (Importer.getToContext()) CXXOperatorCallExpr(
+          Importer.getToContext(), OCE->getOperator(), ToCallee, ToArgs, T,
+          OCE->getValueKind(), Importer.Import(OCE->getRParenLoc()),
+          OCE->getFPFeatures());
+  }
+
   return new (Importer.getToContext())
     CallExpr(Importer.getToContext(), ToCallee, 
              llvm::makeArrayRef(ToArgs_Copied, NumArgs), T, E->getValueKind(),
              Importer.Import(E->getRParenLoc()));
 }
 
 Expr *ASTNodeImporter::VisitInitListExpr(InitListExpr *ILE) {
   QualType T = Importer.Import(ILE->getType());

 
 void ASTNodeImporter::ImportOverrides(CXXMethodDecl *ToMethod,
                                       CXXMethodDecl *FromMethod) {
   for (auto *FromOverriddenMethod : FromMethod->overridden_methods())
     ToMethod->addOverriddenMethod(
       cast<CXXMethodDecl>(Importer.Import(const_cast<CXXMethodDecl*>(
                                             FromOverriddenMethod))));
 }
 
 ASTImporter::ASTImporter(ASTContext &ToContext, FileManager &ToFileManager,
                          ASTContext &FromContext, FileManager &FromFileManager,
                          bool MinimalImport)
   : ToContext(ToContext), FromContext(FromContext),
     ToFileManager(ToFileManager), FromFileManager(FromFileManager),
     Minimal(MinimalImport), LastDiagFromFrom(false)
 {
   ImportedDecls[FromContext.getTranslationUnitDecl()]

unittests/AST/ASTImporterTest.cpp

testImport("void declToImport(__builtin_va_list list, ...) {"
                hasBody(
                  compoundStmt(
                    has(
                      cStyleCastExpr(
                        hasSourceExpression(
                          vaArgExpr())))))));
 }
 
+TEST(ImportExpr, CXXTemporaryObjectExpr) {
+  MatchVerifier<Decl> Verifier;
+  testImport("struct C {};"
+             "void declToImport() { C c = C(); }",
+             Lang_CXX, "", Lang_CXX, Verifier,
+             functionDecl(hasBody(compoundStmt(has(
+                 declStmt(has(varDecl(has(exprWithCleanups(has(cxxConstructExpr(
+                     has(materializeTemporaryExpr(has(implicitCastExpr(
+                         has(cxxTemporaryObjectExpr())))))))))))))))));
+}
 
 TEST(ImportType, ImportAtomicType) {
   MatchVerifier<Decl> Verifier;
   testImport("void declToImport() { typedef _Atomic(int) a_int; }",
              Lang_CXX11, "", Lang_CXX11, Verifier,
              functionDecl(
                hasBody(
                  compoundStmt(
testImport("template <typename... Args>"
                    has(
                      returnStmt(
                        has(
                          implicitCastExpr(
                            has(
                              declRefExpr())))))))));
 }
 
+const internal::VariadicDynCastAllOfMatcher<Type,
+                                            DependentTemplateSpecializationType>
+    dependentTemplateSpecializationType;
+
+TEST(ImportType, ImportDependentTemplateSpecialization) {
+  MatchVerifier<Decl> Verifier;
+  testImport("template<typename T>"
+             "struct A;"
+             "template<typename T>"
+             "struct declToImport {"
+             "  typename A<T>::template B<T> a;"
+             "};",
+             Lang_CXX, "", Lang_CXX, Verifier,
+             classTemplateDecl(has(cxxRecordDecl(has(
+                 fieldDecl(hasType(dependentTemplateSpecializationType())))))));
+}
+
+const internal::VariadicDynCastAllOfMatcher<Stmt, SizeOfPackExpr>
+    sizeOfPackExpr;
+
+TEST(ImportExpr, ImportSizeOfPackExpr) {
+  MatchVerifier<Decl> Verifier;
+  testImport("template <typename... Ts>"
+             "void declToImport() {"
+             "  const int i = sizeof...(Ts);"
+             "};"
+             "void g() { declToImport<int>(); }",
+             Lang_CXX11, "", Lang_CXX11, Verifier,
+             functionTemplateDecl(has(functionDecl(
+                 hasBody(compoundStmt(has(declStmt(has(varDecl(hasInitializer(
+                     implicitCastExpr(has(sizeOfPackExpr())))))))))))));
+  testImport(
+      "template <typename... Ts>"
+      "using X = int[sizeof...(Ts)];"
+      "template <typename... Us>"
+      "struct Y {"
+      "  X<Us..., int, double, int, Us...> f;"
+      "};"
+      "Y<float, int> declToImport;",
+      Lang_CXX11, "", Lang_CXX11, Verifier,
+      varDecl(hasType(classTemplateSpecializationDecl(has(fieldDecl(hasType(
+          hasUnqualifiedDesugaredType(constantArrayType(hasSize(7))))))))));
+}
+
 /// \brief Matches __builtin_types_compatible_p:
 /// GNU extension to check equivalent types
 /// Given
 /// \code
 ///   __builtin_types_compatible_p(int, int)
 /// \endcode
 //  will generate TypeTraitExpr <...> 'int'
 const internal::VariadicDynCastAllOfMatcher<Stmt, TypeTraitExpr> typeTraitExpr;
TEST(ImportExpr, ImportTypeTraitExprValDep) {
   testImport("template<typename T> struct declToImport {"
              "  void m() { __is_pod(T); }"
              "};"
              "void f() { declToImport<int>().m(); }",
              Lang_CXX11, "", Lang_CXX11, Verifier,
              classTemplateDecl(
                has(
                  cxxRecordDecl(
                    has(
                      functionDecl(
                        hasBody(
                          compoundStmt(
                            has(
                              typeTraitExpr(
                                hasType(booleanType())
                                ))))))))));
 }
testImport("template <typename T> class C { T t; };"
              "  (&d)->t = T();"
              "}"
              "void instantiate() { declToImport<int>(); }",
              Lang_CXX, "", Lang_CXX, Verifier,
              functionTemplateDecl(has(functionDecl(has(compoundStmt(has(
                  binaryOperator(has(cxxUnresolvedConstructExpr())))))))));
 }
 
+TEST(ImportExpr, CXXOperatorCallExpr) {
+  MatchVerifier<Decl> Verifier;
+  testImport("class declToImport {"
+             "  void f() { *this = declToImport(); }"
+             "};",
+             Lang_CXX, "", Lang_CXX, Verifier,
+             cxxRecordDecl(has(cxxMethodDecl(hasBody(compoundStmt(
+                 has(exprWithCleanups(has(cxxOperatorCallExpr())))))))));
+}
+
+TEST(ImportExpr, DependentSizedArrayType) {
+  MatchVerifier<Decl> Verifier;
+  testImport("template<typename T, int Size> class declToImport {"
+             "  T data[Size];"
+             "};",
+             Lang_CXX, "", Lang_CXX, Verifier,
+             classTemplateDecl(has(cxxRecordDecl(
+                 has(fieldDecl(hasType(dependentSizedArrayType())))))));
+}
+
 } // end namespace ast_matchers
 } // end namespace clang