`decl_macro` can call `pub fn` methods of private types.

I tried this code:

#![feature(decl_macro)]
macro my_macro($val:expr) {
    $val.method()
}

pub mod module {
    struct Thing;
    impl Thing {
        pub fn method(&self) -> bool {
            true
        }
    }
    pub fn weird() -> bool {
        super::my_macro!(Thing)
    }
}

The method is a pub fn. However, it is implemented on a private type. Therefore, it should not be callable from outside the module. So, this code shouldn't compile. Instead, this code compiles without errors.

Changing pub fn method to fn method causes the following error, as expected:

error[E0624]: method `method` is private
  --> src/lib.rs:3:10
   |
 3 |     $val.method()
   |          ^^^^^^ private method
...
 9 |         fn method(&self) -> bool {
   |         ------------------------ private method defined here
...
14 |         super::my_macro!(Thing)
   |         ----------------------- in this macro invocation
   |
   = note: this error originates in the macro `super::my_macro` (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try `rustc --explain E0624`.

This behavior also seems to apply to built-in macros. See https://github.com/rust-lang/rust/pull/155598#discussion_r3121501324

Meta

Reproducible on the playground with 1.97.0-nightly (2026-04-20 66da6cae1a6f12e95854)

Start with the provided playground reproduction using decl_macro, then trace the compiler's macro expansion and privacy checking for the pub fn method on the private Thing type. Compare the behavior with the non-public method and the mentioned built-in macro case; done means the reproduction is rejected for the expected privacy violation without regressing valid macro calls.