A slightly more concise AST dump :)

[merrymeerkat]

Summary

If the modifiedType and the minimally desugared type of an AttributedType are the same, then we do not need to show both in an AST dump.

Here, we change VisitAttributedType to only visit the modifiedType when it is different from the equivalentType (the minimally desugared type), because the latter is already visited by default.

[sammccall]

clang/test/AST/ast-dump-attr-type.cpp

13

Can you add a second example where the attribute is not mere sugar, showing that both types get printed?

The example from the AttributedType doc is vector_size, which would work

[gribozavr2]

clang/test/AST/ast-dump-attr-type.cpp

13

Please replace the exact pointer value with a regex.

[sammccall]

clang/test/AST/ast-dump-attr-type.cpp

13

Oops, yes. In fact just CHECK-NOT: PointerType seems like enough

[merrymeerkat]

Addressing review comments (improve tests)

[merrymeerkat]

thank you @sammccall @gribozavr2 for spotting these issues!

clang/include/clang/AST/ASTNodeTraverser.h

public:
   void VisitDecltypeType(const DecltypeType *T) {
     Visit(T->getUnderlyingExpr());
   }
   void VisitUnaryTransformType(const UnaryTransformType *T) {
     Visit(T->getBaseType());
   }
   void VisitAttributedType(const AttributedType *T) {
     // FIXME: AttrKind
+    if (T->getModifiedType() != T->getEquivalentType())
       Visit(T->getModifiedType());
   }
   void VisitBTFTagAttributedType(const BTFTagAttributedType *T) {
     Visit(T->getWrappedType());
   }
   void VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *) {}
   void
   VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
     Visit(T->getArgumentPack());

clang/test/AST/ast-dump-attr-type.cpp

+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -ast-dump %s | FileCheck %s
+
+int * _Nonnull x;
+using Ty = decltype(x);
+
+// CHECK: TypeAliasDecl 0x{{[^ ]*}}  <line:4:1, col:22> col:7 Ty 'decltype(x)':'int *'
+// CHECK-NEXT:  `-DecltypeType 0x{{[^ ]*}} 'decltype(x)' sugar
+// CHECK-NEXT:     |-DeclRefExpr 0x{{[^ ]*}} <col:21> 'int * _Nonnull':'int *' lvalue Var 0x{{[^ ]*}} 'x' 'int * _Nonnull':'int *' non_odr_use_unevaluated
+// CHECK-NEXT:    `-AttributedType 0x{{[^ ]*}} 'int * _Nonnull' sugar
+// CHECK-NEXT:      `-PointerType 0x{{[^ ]*}} 'int *'
+// CHECK-NEXT:        `-BuiltinType 0x{{[^ ]*}} 'int'
+// CHECK-NOT:       `-PointerType
+
+[[clang::address_space(3)]] int *y;
+using Ty1 = decltype(y);
+
+// CHECK: TypeAliasDecl 0x{{[^ ]*}} <line:15:1, col:23> col:7 Ty1 'decltype(y)':'__attribute__((address_space(3))) int *'
+// CHECK-NEXT: `-DecltypeType 0x{{[^ ]*}} 'decltype(y)' sugar
+// CHECK-NEXT:   |-DeclRefExpr 0x{{[^ ]*}} <col:22> '__attribute__((address_space(3))) int *' lvalue Var 0x{{[^ ]*}} 'y' '__attribute__((address_space(3))) int *' non_odr_use_unevaluated
+// CHECK-NEXT:     `-PointerType 0x{{[^ ]*}} '__attribute__((address_space(3))) int *'
+// CHECK-NEXT:       `-AttributedType 0x{{[^ ]*}} '__attribute__((address_space(3))) int' sugar
+// CHECK-NEXT          |-BuiltinType 0x{{[^ ]*}} 'int'
+// CHECK-NEXT          `-QualType 0x{{[^ ]*}} '__attribute__((address_space(3))) int' __attribute__((address_space(3)))
+// CHECK-NEXT            `-BuiltinType 0x{{[^ ]*}} 'int'

clang/test/AST/ast-dump-types-json.cpp

 // CHECK-NEXT:              "kind": "BuiltinType",
 // CHECK-NEXT:              "type": {
 // CHECK-NEXT:               "qualType": "void"
 // CHECK-NEXT:              }
 // CHECK-NEXT:             }
 // CHECK-NEXT:            ]
 // CHECK-NEXT:           }
 // CHECK-NEXT:          ]
-// CHECK-NEXT:         },
-// CHECK-NEXT:         {
-// CHECK-NEXT:          "id": "0x{{.*}}",
-// CHECK-NEXT:          "kind": "ParenType",
-// CHECK-NEXT:          "type": {
-// CHECK-NEXT:           "qualType": "void ()"
-// CHECK-NEXT:          },
-// CHECK-NEXT:          "inner": [
-// CHECK-NEXT:           {
-// CHECK-NEXT:            "id": "0x{{.*}}",
-// CHECK-NEXT:            "kind": "FunctionProtoType",
-// CHECK-NEXT:            "type": {
-// CHECK-NEXT:             "qualType": "void ()"
-// CHECK-NEXT:            },
-// CHECK-NEXT:            "cc": "cdecl",
-// CHECK-NEXT:            "inner": [
-// CHECK-NEXT:             {
-// CHECK-NEXT:              "id": "0x{{.*}}",
-// CHECK-NEXT:              "kind": "BuiltinType",
-// CHECK-NEXT:              "type": {
-// CHECK-NEXT:               "qualType": "void"
-// CHECK-NEXT:              }
-// CHECK-NEXT:             }
-// CHECK-NEXT:            ]
-// CHECK-NEXT:           }
-// CHECK-NEXT:          ]
 // CHECK-NEXT:         }
 // CHECK-NEXT:        ]
 // CHECK-NEXT:       }
 // CHECK-NEXT:      ]
 // CHECK-NEXT:     }
 // CHECK-NEXT:    ]
 // CHECK-NEXT:   }
 // CHECK-NEXT:  ]