From a27a17f883864c1c44a0ba3fb01bbf1c89110b82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?= <1.int32@gmail.com>
Date: Fri, 2 Jul 2021 09:08:54 +0200
Subject: [PATCH] [clang][AST] Add support for BindingDecl to ASTImporter.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D102492
---
 clang/lib/AST/ASTImporter.cpp           | 30 ++++++++++++++++
 clang/unittests/AST/ASTImporterTest.cpp | 46 +++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 0d0cabc96556..8fb55488e836 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -496,6 +496,7 @@ namespace clang {
     ExpectedDecl VisitAccessSpecDecl(AccessSpecDecl *D);
     ExpectedDecl VisitStaticAssertDecl(StaticAssertDecl *D);
     ExpectedDecl VisitTranslationUnitDecl(TranslationUnitDecl *D);
+    ExpectedDecl VisitBindingDecl(BindingDecl *D);
     ExpectedDecl VisitNamespaceDecl(NamespaceDecl *D);
     ExpectedDecl VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
     ExpectedDecl VisitTypedefNameDecl(TypedefNameDecl *D, bool IsAlias);
@@ -2291,6 +2292,35 @@ ExpectedDecl ASTNodeImporter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
   return ToD;
 }
 
+ExpectedDecl ASTNodeImporter::VisitBindingDecl(BindingDecl *D) {
+  DeclContext *DC, *LexicalDC;
+  DeclarationName Name;
+  SourceLocation Loc;
+  NamedDecl *ToND;
+  if (Error Err = ImportDeclParts(D, DC, LexicalDC, Name, ToND, Loc))
+    return std::move(Err);
+  if (ToND)
+    return ToND;
+
+  Error Err = Error::success();
+  QualType ToType = importChecked(Err, D->getType());
+  Expr *ToBinding = importChecked(Err, D->getBinding());
+  ValueDecl *ToDecomposedDecl = importChecked(Err, D->getDecomposedDecl());
+  if (Err)
+    return std::move(Err);
+
+  BindingDecl *ToD;
+  if (GetImportedOrCreateDecl(ToD, D, Importer.getToContext(), DC, Loc,
+                              Name.getAsIdentifierInfo()))
+    return ToD;
+
+  ToD->setBinding(ToType, ToBinding);
+  ToD->setDecomposedDecl(ToDecomposedDecl);
+  addDeclToContexts(D, ToD);
+
+  return ToD;
+}
+
 ExpectedDecl ASTNodeImporter::VisitAccessSpecDecl(AccessSpecDecl *D) {
   ExpectedSLoc LocOrErr = import(D->getLocation());
   if (!LocOrErr)
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index da4bce16d23b..3536b1cfcbff 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -3679,6 +3679,52 @@ TEST_P(ImportVariables, InitAndDefinitionAreInTheFromContext) {
   EXPECT_TRUE(ImportedD->getDefinition());
 }
 
+TEST_P(ImportVariables, ImportBindingDecl) {
+  Decl *From, *To;
+  std::tie(From, To) = getImportedDecl(
+      R"(
+      void declToImport() {
+        int a[2] = {1,2};
+        auto [x1,y1] = a;
+        auto& [x2,y2] = a;
+        
+        struct S {
+          mutable int x1 : 2;
+          volatile double y1;
+        };
+        S b;
+        const auto [x3, y3] = b;
+      };
+      )",
+      Lang_CXX17, "", Lang_CXX17);
+
+  TranslationUnitDecl *FromTU = From->getTranslationUnitDecl();
+  auto *FromF = FirstDeclMatcher<FunctionDecl>().match(
+      FromTU, functionDecl(hasName("declToImport")));
+  auto *ToF = Import(FromF, Lang_CXX17);
+  EXPECT_TRUE(ToF);
+
+  auto VerifyImport = [&](llvm::StringRef BindName) {
+    auto *FromB = FirstDeclMatcher<BindingDecl>().match(
+        FromF, bindingDecl(hasName(BindName)));
+    ASSERT_TRUE(FromB);
+    auto *ToB = Import(FromB, Lang_CXX17);
+    EXPECT_TRUE(ToB);
+    EXPECT_EQ(FromB->getBinding() != nullptr, ToB->getBinding() != nullptr);
+    EXPECT_EQ(FromB->getDecomposedDecl() != nullptr,
+              ToB->getDecomposedDecl() != nullptr);
+    EXPECT_EQ(FromB->getHoldingVar() != nullptr,
+              ToB->getHoldingVar() != nullptr);
+  };
+
+  VerifyImport("x1");
+  VerifyImport("y1");
+  VerifyImport("x2");
+  VerifyImport("y2");
+  VerifyImport("x3");
+  VerifyImport("y3");
+}
+
 struct ImportClasses : ASTImporterOptionSpecificTestBase {};
 
 TEST_P(ImportClasses, ImportDefinitionWhenProtoIsInNestedToContext) {