Misleading error message for bad export statement

[brson]

export output_format::{};
export output_styl::{};
export config;

#[doc = "The type of document to output"]
enum output_format {
    #[doc = "Markdown"]
    markdown,
    #[doc = "HTML, via markdown and pandoc"]
    pandoc_html
}

#[doc = "How to organize the output"]
enum output_style {
    #[doc = "All in a single document"]
    one_doc,
    #[doc = "Each module in its own document"]
    doc_per_mod
}

#[doc = "The configuration for this rustdoc session"]
type config = {
    output_dir: str,
    output_format: output_format,
    output_style: output_style,
    pandoc_cmd: option<str>
};

../src/rustdoc/config.rs:2:7: 2:23 error: error: undefined id output_styl in an export
../src/rustdoc/config.rs:2 export output_styl::{};

An 'id' isn't a language concept so probably shouldn't appear in the UI. Maybe 'identifier', or even 'enum' if we actually know this is checking enums.

[brson]

Also, we don't need to write 'error' a second time.

[kud1ing]

And maybe also enclose the id in backticks, like in undefined id output_styl in an export.

[brson]

Yeah, should use backticks. I happened to remove the extra 'error' in a cleanup fit yesterday.

[catamorphism]

The error message comes from resolve, so assigning @marijnh

[bstrie]

Had to make some changes to keep the example up to date, but note that it compiles despite the fact that it exports something that doesn't exist.

export output_format;
export output_styl;
export config;

#[doc = "The type of document to output"]
enum output_format {
    #[doc = "Markdown"]
    markdown,
    #[doc = "HTML, via markdown and pandoc"]
    pandoc_html
}

#[doc = "How to organize the output"]
enum output_style {
    #[doc = "All in a single document"]
    one_doc,
    #[doc = "Each module in its own document"]
    doc_per_mod
}

#[doc = "The configuration for this rustdoc session"]
type config = {
    output_dir: &str,
    output_format: output_format,
    output_style: output_style,
    pandoc_cmd: option<&str>
};

Compiled with rustc --lib 1908.rs.

[catamorphism]

Blocked on #1893 (export statements will go away altogether).

[catamorphism]

Since exports are on the way out, this is obsolete.