From 6e0866987949be9d1300a82c957bb5c1cef79d58 Mon Sep 17 00:00:00 2001
From: Balazs Keri <1.int32@gmail.com>
Date: Mon, 2 Sep 2019 07:17:01 +0000
Subject: [PATCH] [ASTImporter] At import of records re-order indirect fields
 too.

Summary:
Correct order of fields and indirect fields in imported RecordDecl
is needed for correct work of record layout calculations.

Reviewers: martong, a.sidorin, shafik, a_sidorin

Reviewed By: martong, a_sidorin

Subscribers: rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66866

llvm-svn: 370621
---
 clang/lib/AST/ASTImporter.cpp           |  2 +-
 clang/unittests/AST/ASTImporterTest.cpp | 40 +++++++++++++++++++++----
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 5ee9f760b6a2..417a97c44d59 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -1702,7 +1702,7 @@ ASTNodeImporter::ImportDeclContext(DeclContext *FromDC, bool ForceImport) {
   // Remove all declarations, which may be in wrong order in the
   // lexical DeclContext and then add them in the proper order.
   for (auto *D : FromRD->decls()) {
-    if (isa<FieldDecl>(D) || isa<FriendDecl>(D)) {
+    if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D) || isa<FriendDecl>(D)) {
       assert(D && "DC contains a null decl");
       Decl *ToD = Importer.GetAlreadyImportedOrNull(D);
       // Remove only the decls which we successfully imported.
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index cfee284e6875..17696a38e94f 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -1421,12 +1421,15 @@ TEST_P(ASTImporterOptionSpecificTestBase,
 
 AST_MATCHER_P(RecordDecl, hasFieldOrder, std::vector<StringRef>, Order) {
   size_t Index = 0;
-  for (FieldDecl *Field : Node.fields()) {
-    if (Index == Order.size())
-      return false;
-    if (Field->getName() != Order[Index])
-      return false;
-    ++Index;
+  for (Decl *D : Node.decls()) {
+    if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) {
+      auto *ND = cast<NamedDecl>(D);
+      if (Index == Order.size())
+        return false;
+      if (ND->getName() != Order[Index])
+        return false;
+      ++Index;
+    }
   }
   return Index == Order.size();
 }
@@ -1493,6 +1496,31 @@ TEST_P(ASTImporterOptionSpecificTestBase,
       Verifier.match(To, cxxRecordDecl(hasFieldOrder({"a", "b", "c"}))));
 }
 
+TEST_P(ASTImporterOptionSpecificTestBase,
+       CXXRecordDeclFieldAndIndirectFieldOrder) {
+  Decl *From, *To;
+  std::tie(From, To) = getImportedDecl(
+      // First field is "a", then the field for unnamed union, then "b" and "c"
+      // from it (indirect fields), then "d".
+      R"s(
+      struct declToImport {
+        int a = d;
+        union { 
+          int b;
+          int c;
+        };
+        int d;
+      };
+      )s",
+      Lang_CXX11, "", Lang_CXX11);
+
+  MatchVerifier<Decl> Verifier;
+  ASSERT_TRUE(Verifier.match(
+      From, cxxRecordDecl(hasFieldOrder({"a", "", "b", "c", "d"}))));
+  EXPECT_TRUE(Verifier.match(
+      To, cxxRecordDecl(hasFieldOrder({"a", "", "b", "c", "d"}))));
+}
+
 TEST_P(ASTImporterOptionSpecificTestBase, ShouldImportImplicitCXXRecordDecl) {
   Decl *From, *To;
   std::tie(From, To) = getImportedDecl(