#[doc ="..."] comments no longer allow escaped newlines

[siefkenj]

In rust-analyzer rust-analyzer version: 0.3.1885-standalone (b6d1887bc 2024-03-17) in vscode, when writing a doc comment

#[doc = "\n\nThis is a \"quote\".\n\nFoo"]
fn main() {}

hovering over main() shows the doc comment as expected, with newlines. However, in rust-analyzer rust-analyzer version: 0.3.1896-standalone, while the quote characters display correctly, literal \n (backslash n) tokens appear in the tooltip.

[roife]

It might be caused by #16909.

update:

rust-analyzer/crates/hir-expand/src/attrs.rs

Lines 232 to 236 in f5a9250

	let input = if let Some(ast::Expr::Literal(lit)) = ast.expr() {
	Some(Interned::new(AttrInput::Literal(tt::Literal {
	text: lit.token().text().into(),
	span,
	})))

rust-analyzer/crates/hir-expand/src/attrs.rs

Lines 290 to 295 in e4a405f

	AttrInput::Literal(it) => match it.text.strip_prefix('r') {
	Some(it) => it.trim_matches('#'),
	None => it.text.as_str(),
	}
	.strip_prefix('"')?
	.strip_suffix('"'),

I guess we keep the whole token text to match spans. But I don't think using strip to get the string is a good approach since we can't distinguish between a raw-string and a normal string (in which characters can be escaped). And I found that when doc comments are within #[doc], \n should be escaped; whereas within /// it won't be escaped, the current code cannot handle this situation.

[roife]

@rustbot claim