[THRIFT-5550] error: an inner attribute is not permitted in this context

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Rust - Compiler
• Assignee: Unassigned
• Reporter: Francisco Ayala
• Created: 10/Apr/22 10:19
• Updated: 10/Apr/22 10:19

Description

Right now the compiler generates inner attributes at the top of each generated source file:

#![allow(unused_imports)]
#![allow(unused_extern_crates)]
#![allow(clippy::too_many_arguments, clippy::type_complexity, clippy::vec_box)]
#![cfg_attr(rustfmt, rustfmt_skip)]

If rust source files are generated by the project's build.rs file, then they must be included in the following way:

include!(concat!(env!("OUT_DIR"), "/service.rs")); 

However, doing this leads to errors of the following form:

error: an inner attribute is not permitted in this context
 --> /thrift-test/target/debug/build/thrift-test-345cae8ce43a395d/out/service.rs:4:1
  |
4 | #![allow(unused_imports)]
  | ^^^^^^^^^^^^^^^^^^^^^^^^^
...
9 | use std::cell::RefCell;
  | ----------------------- the inner attribute doesn't annotate this `use` import
  |
  = note: inner attributes, like `#![no_std]`, annotate the item enclosing them, and are usually found at the beginning of source files
help: to annotate the `use` import, change the attribute from inner to outer style
  |
4 - #![allow(unused_imports)]
4 + #[allow(unused_imports)] 

Related:

https://github.com/google/flatbuffers/issues/6261