[ASTImporter] Fix crash caused by unset AttributeSpellingListIndex

During the import of attributes we forgot to set the spelling list
index. This caused a segfault when we wanted to traverse the AST
(e.g. by the dump() method).

Differential Revision: https://reviews.llvm.org/D89318

Author: Gabor Marton

clang/lib/AST/ASTImporter.cpp

@@ -8094,9 +8094,6 @@ Expected<Attr *> ASTImporter::Import(const Attr *FromAttr) {
       else
         return ToTOrErr.takeError();
     }
-    To->setInherited(From->isInherited());
-    To->setPackExpansion(From->isPackExpansion());
-    To->setImplicit(From->isImplicit());
     ToAttr = To;
     break;
   }
@@ -8106,7 +8103,6 @@ Expected<Attr *> ASTImporter::Import(const Attr *FromAttr) {
     IdentifierInfo *ToAttrType = Import(From->getType());
     To = FormatAttr::Create(ToContext, ToAttrType, From->getFormatIdx(),
                             From->getFirstArg(), ToRange, From->getSyntax());
-    To->setInherited(From->isInherited());
     ToAttr = To;
     break;
   }
@@ -8117,8 +8113,15 @@ Expected<Attr *> ASTImporter::Import(const Attr *FromAttr) {
     ToAttr->setRange(ToRange);
     break;
   }
+
   assert(ToAttr && "Attribute should be created.");
-  
+  if (const auto *InheritableFromAttr = dyn_cast<InheritableAttr>(FromAttr))
+    cast<InheritableAttr>(ToAttr)->setInherited(
+        InheritableFromAttr->isInherited());
+  ToAttr->setAttributeSpellingListIndex(
+      FromAttr->getAttributeSpellingListIndex());
+  ToAttr->setPackExpansion(FromAttr->isPackExpansion());
+  ToAttr->setImplicit(FromAttr->isImplicit());
   return ToAttr;
 }
 

clang/test/ASTMerge/attr/Inputs/RestrictAttr.cpp

@@ -0,0 +1 @@
+void *foo(unsigned, unsigned) __attribute__((__malloc__));

clang/test/ASTMerge/attr/testRestrictAttr.cpp

@@ -0,0 +1,2 @@
+// RUN: %clang -x c++-header -o %t.a.ast %S/Inputs/RestrictAttr.cpp
+// RUN: %clang_cc1 -x c++ -ast-merge %t.a.ast /dev/null -ast-dump

clang/unittests/AST/ASTImporterTest.cpp

@@ -5767,11 +5767,35 @@ TEST_P(ASTImporterOptionSpecificTestBase, ImportExprOfAlignmentAttr) {
   EXPECT_TRUE(ToA);
 }
 
+TEST_P(ASTImporterOptionSpecificTestBase, ImportRestrictAttr) {
+  Decl *FromTU = getTuDecl(
+      R"(
+      void *foo(unsigned, unsigned) __attribute__((__malloc__));
+      )",
+      Lang_CXX03, "input.cc");
+  auto *FromD = FirstDeclMatcher<FunctionDecl>().match(
+      FromTU, functionDecl(hasName("foo")));
+  ASSERT_TRUE(FromD);
+
+  auto *ToD = Import(FromD, Lang_CXX03);
+  ASSERT_TRUE(ToD);
+  ToD->dump(); // Should not crash!
+
+  auto *FromAttr = FromD->getAttr<RestrictAttr>();
+  auto *ToAttr = ToD->getAttr<RestrictAttr>();
+  EXPECT_EQ(FromAttr->isInherited(), ToAttr->isInherited());
+  EXPECT_EQ(FromAttr->isPackExpansion(), ToAttr->isPackExpansion());
+  EXPECT_EQ(FromAttr->isImplicit(), ToAttr->isImplicit());
+  EXPECT_EQ(FromAttr->getSyntax(), ToAttr->getSyntax());
+  EXPECT_EQ(FromAttr->getAttributeSpellingListIndex(),
+            ToAttr->getAttributeSpellingListIndex());
+}
+
 TEST_P(ASTImporterOptionSpecificTestBase, ImportFormatAttr) {
   Decl *FromTU = getTuDecl(
       R"(
       int foo(const char * fmt, ...)
-      __attribute__ ((__format__ (__scanf__, 1, 2)));
+          __attribute__ ((__format__ (__scanf__, 1, 2)));
       )",
       Lang_CXX03, "input.cc");
   auto *FromD = FirstDeclMatcher<FunctionDecl>().match(
@@ -5792,6 +5816,7 @@ TEST_P(ASTImporterOptionSpecificTestBase, ImportFormatAttr) {
             ToAttr->getAttributeSpellingListIndex());
   EXPECT_EQ(FromAttr->getType()->getName(), ToAttr->getType()->getName());
 }
+
 template <typename T>
 auto ExtendWithOptions(const T &Values, const std::vector<std::string> &Args) {
   auto Copy = Values;