const field inside class is not handled correctly on Windows

[upsuper]

Test code:

class A {
  const size_t count;
};

On Windows, it generates:

#[repr(C)]
#[derive(Debug, Copy)]
pub struct A {
    pub count: A_size_t,
}

where A_size_t is never defined.

[emilio]

I don't think this would reproduce if size_t was defined, does it?

i.e., I can't reproduce if I instead:

typedef unsigned size_t; // Or define it in some other way.

class A {
  const size_t count;
};

[upsuper]

It doesn't matter.

typedef unsigned long long size_t;
class A {
  const size_t count;
};

still gives me

#[repr(C)]
#[derive(Debug, Copy)]
pub struct A {
    pub count: A_size_t,
}

FWIW, I can only reproduce this on Windows. It works fine on my macOS. I have no idea why...

[emilio]

Gah, github-debugging time again :).

Can you use --emit-clang-ast and paste it here?

[emilio]

The bindgen logs will also help, I guess.

[upsuper]

This is the log with RUST_LOG=bindgen cargo run -- test.h --emit-clang-ast -- -x c++ -std=c++14, and test.h is the file I pasted in my previous comment.

[emilio]

Can you use RUST_LOG=libbindgen (the crate was split in #204)? Also, it seems clang is ignoring the -x c++ argument, per the first warning, does it reproduce if instead of test.h it you call the file test.hpp?

[upsuper]

This is log.txt from RUST_LOG=bindgen,libbindgen cargo run -- test.hpp --emit-clang-ast -- -std=c++14.

[emilio]

So it's again an MSVC backend bug, where they report no USR for the typedef declaration, so we don't find it and assume that "const size_t" is a type declared inside of A...

[emilio]

@upsuper, does the following patch make it work for you?

diff --git a/libbindgen/src/ir/context.rs b/libbindgen/src/ir/context.rs
index a1ec8c7..bda3e3c 100644
--- a/libbindgen/src/ir/context.rs
+++ b/libbindgen/src/ir/context.rs
@@ -222,7 +222,7 @@ impl<'ctx> BindgenContext<'ctx> {
                 error!("Valid declaration with no USR: {:?}, {:?}",
                        declaration,
                        location);
-                return;
+                TypeKey::Declaration(declaration)
             };

             let old = self.types.insert(key, id);

[upsuper]

Yes, it seems to work. Thanks.

[emilio]

I added the fix in #260, should be merged soon.

Thank you for reporting it :)