[ASTImporter] Typedef import brings in the complete type

Summary:
When we already have an incomplete underlying type of a typedef in the
"To" context, and the "From" context has the same typedef, but the
underlying type is complete, then the imported type should be complete.

Fixes an assertion in CTU analysis of Xerces:
Assertion `DD && "queried property of class with no definition"' failed.
This assert is happening in the analyzer engine, because that attempts
to query an underlying type of a typedef, which happens to be
incomplete.

Reviewers: a_sidorin, a.sidorin

Subscribers: rnkovacs, dkrupp, Szelethus, cfe-commits

Differential Revision: https://reviews.llvm.org/D53693

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@347648 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 77a1a7f4990aa6833ad6c03f7314e750cb2bfc8e..67feef16f26ef57143829f2bcffde8eded5ae743 100644 (file)
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -2311,9 +2311,16 @@ ASTNodeImporter::VisitTypedefNameDecl(TypedefNameDecl *D, bool IsAlias) {
       if (!FoundDecl->isInIdentifierNamespace(IDNS))
         continue;
       if (auto *FoundTypedef = dyn_cast<TypedefNameDecl>(FoundDecl)) {
-        if (Importer.IsStructurallyEquivalent(
-                D->getUnderlyingType(), FoundTypedef->getUnderlyingType()))
+        QualType FromUT = D->getUnderlyingType();
+        QualType FoundUT = FoundTypedef->getUnderlyingType();
+        if (Importer.IsStructurallyEquivalent(FromUT, FoundUT)) {
+          // If the "From" context has a complete underlying type but we
+          // already have a complete underlying type then return with that.
+          if (!FromUT->isIncompleteType() && !FoundUT->isIncompleteType())
             return Importer.MapImported(D, FoundTypedef);
+        }
+        // FIXME Handle redecl chain.
+        break;
       }
 
       ConflictingDecls.push_back(FoundDecl);

diff --git a/unittests/AST/ASTImporterTest.cpp b/unittests/AST/ASTImporterTest.cpp
index 3a0ee5d129c5f6862b308c1699c7168577fe445c..0450cb41a408e111a14e66b38d0e2f665ab9e201 100644 (file)
--- a/unittests/AST/ASTImporterTest.cpp
+++ b/unittests/AST/ASTImporterTest.cpp
@@ -3764,6 +3764,38 @@ TEST_P(ASTImporterTestBase,
   }
 }
 
+TEST_P(ASTImporterTestBase, ImportingTypedefShouldImportTheCompleteType) {
+  // We already have an incomplete underlying type in the "To" context.
+  auto Code =
+      R"(
+      template <typename T>
+      struct S {
+        void foo();
+      };
+      using U = S<int>;
+      )";
+  Decl *ToTU = getToTuDecl(Code, Lang_CXX11);
+  auto *ToD = FirstDeclMatcher<TypedefNameDecl>().match(ToTU,
+      typedefNameDecl(hasName("U")));
+  ASSERT_TRUE(ToD->getUnderlyingType()->isIncompleteType());
+
+  // The "From" context has the same typedef, but the underlying type is
+  // complete this time.
+  Decl *FromTU = getTuDecl(std::string(Code) +
+      R"(
+      void foo(U* u) {
+        u->foo();
+      }
+      )", Lang_CXX11);
+  auto *FromD = FirstDeclMatcher<TypedefNameDecl>().match(FromTU,
+      typedefNameDecl(hasName("U")));
+  ASSERT_FALSE(FromD->getUnderlyingType()->isIncompleteType());
+
+  // The imported type should be complete.
+  auto *ImportedD = cast<TypedefNameDecl>(Import(FromD, Lang_CXX11));
+  EXPECT_FALSE(ImportedD->getUnderlyingType()->isIncompleteType());
+}
+
 INSTANTIATE_TEST_CASE_P(ParameterizedTests, DeclContextTest,
                         ::testing::Values(ArgVector()), );