libclang: how to visit implicit declarations.

[phadej]

Consider simple u.h header

union u {
        int big;
        struct {
                char small1;
                char small2;
        };
};

clang -Xclang -ast-dump -fsyntax-only prints

`-RecordDecl 0xeba4a10 <u.h:1:1, line:7:1> line:1:7 union u definition
  |-FieldDecl 0xeba4ac8 <line:2:2, col:6> col:6 big 'int'
  |-RecordDecl 0xeba4b18 <line:3:2, line:6:2> line:3:2 struct definition
  | |-FieldDecl 0xeba4bd0 <line:4:3, col:8> col:8 small1 'char'
  | `-FieldDecl 0xeba4c30 <line:5:3, col:8> col:8 small2 'char'
  |-FieldDecl 0xeba4cd8 <line:3:2> col:2 implicit 'struct u::(anonymous at u.h:3:2)'
  |-IndirectFieldDecl 0xeba4d38 <line:4:8> col:8 implicit small1 'char'
  | |-Field 0xeba4cd8 '' 'struct u::(anonymous at u.h:3:2)'
  | `-Field 0xeba4bd0 'small1' 'char'
  `-IndirectFieldDecl 0xeba4d90 <line:5:8> col:8 implicit small2 'char'
    |-Field 0xeba4cd8 '' 'struct u::(anonymous at u.h:3:2)'
    `-Field 0xeba4c30 'small2' 'char'

Notice, there is implicit fielddecl for struct u::(anonymous ...) as well as (implicit?) IndirectFieldDecls.

However, when using libclang interface, in particular, clang_visitChildren only explicit declarations are visiible. I.e. we can only see first two declarations, big 'int' and struct definition.

In some cases it's very inconvenient to work with source code with tagless and/or field-nameless substructures.

Is there a way to also traverse implicit declarations?