rust/src/test/ui/proc-macro/nested-item-spans.rs

// aux-build:nested-item-spans.rs

extern crate nested_item_spans;

use nested_item_spans::foo;

#[foo]
fn another() {
    fn bar() {
        let x: u32 = "x"; //~ ERROR: mismatched types
    }

    bar();
}

fn main() {
    #[foo]
    fn bar() {
        let x: u32 = "x"; //~ ERROR: mismatched types
    }

    bar();
    another();
}
rustc: Implement tokenization of nested items Ever plagued by #43081 the compiler can return surprising spans in situations related to procedural macros. This is exhibited by #47983 where whenever a procedural macro is invoked in a nested item context it would fail to have correct span information. While #43230 provided a "hack" to cache the token stream used for each item in the compiler it's not a full-blown solution. This commit continues to extend this "hack" a bit more to work for nested items. Previously in the parser the `parse_item` method would collect the tokens for an item into a cache on the item itself. It turned out, however, that nested items were parsed through the `parse_item_` method, so they didn't receive similar treatment. To remedy this situation the hook for collecting tokens was moved into `parse_item_` instead of `parse_item`. Afterwards the token collection scheme was updated to support nested collection of tokens. This is implemented by tracking `TokenStream` tokens instead of `TokenTree` to allow for collecting items into streams at intermediate layers and having them interleaved in the upper layers. All in all, this... Closes #47983 2018-07-22 15:48:29 +00:00			`// aux-build:nested-item-spans.rs`

			`extern crate nested_item_spans;`

			`use nested_item_spans::foo;`

			`#[foo]`
			`fn another() {`
			`fn bar() {`
			`let x: u32 = "x"; //~ ERROR: mismatched types`
			`}`

			`bar();`
			`}`

			`fn main() {`
			`#[foo]`
			`fn bar() {`
			`let x: u32 = "x"; //~ ERROR: mismatched types`
			`}`

			`bar();`
			`another();`
			`}`