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rustdoc: Fix doctest heuristic for main fn wrapping

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This commit is contained in:
León Orell Valerian Liehr 2025-04-29 02:11:41 +02:00
parent 25cdf1f674
commit 714ea10ea4
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GPG key ID: D17A07215F68E713
12 changed files with 183 additions and 89 deletions
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67
src/librustdoc/doctest/make.rs
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@ -301,8 +301,6 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
let filename = FileName::anon_source_code(&wrapped_source);
// Any errors in parsing should also appear when the doctest is compiled for real, so just
// send all the errors that librustc_ast emits directly into a `Sink` instead of stderr.
let sm = Arc::new(SourceMap::new(FilePathMapping::empty()));
let fallback_bundle = rustc_errors::fallback_fluent_bundle(
rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(),
@ -311,7 +309,8 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
info.supports_color =
HumanEmitter::new(stderr_destination(ColorConfig::Auto), fallback_bundle.clone())
.supports_color();
// Any errors in parsing should also appear when the doctest is compiled for real, so just
// send all the errors that the parser emits directly into a `Sink` instead of stderr.
let emitter = HumanEmitter::new(Box::new(io::sink()), fallback_bundle);
// FIXME(misdreavus): pass `-Z treat-err-as-bug` to the doctest parser
@ -339,9 +338,6 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
*prev_span_hi = hi;
}
// Recurse through functions body. It is necessary because the doctest source code is
// wrapped in a function to limit the number of AST errors. If we don't recurse into
// functions, we would thing all top-level items (so basically nothing).
fn check_item(item: &ast::Item, info: &mut ParseSourceInfo, crate_name: &Option<&str>) -> bool {
let mut is_extern_crate = false;
if !info.has_global_allocator
@ -351,8 +347,6 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
}
match item.kind {
ast::ItemKind::Fn(ref fn_item) if !info.has_main_fn => {
// We only push if it's the top item because otherwise, we would duplicate
// its content since the top-level item was already added.
if fn_item.ident.name == sym::main {
info.has_main_fn = true;
}
@ -412,7 +406,32 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
let mut is_extern_crate = false;
match stmt.kind {
StmtKind::Item(ref item) => {
is_extern_crate = check_item(&item, &mut info, crate_name);
is_extern_crate = check_item(item, &mut info, crate_name);
}
// We assume that the macro calls will expand to item(s) even though they could
// expand to statements and expressions.
StmtKind::MacCall(ref mac_call) => {
if !info.has_main_fn {
// For backward compatibility, we look for the token sequence `fn main(…)`
// in the macro input (!) to crudely detect main functions "masked by a
// wrapper macro". For the record, this is a horrible heuristic!
// See <https://github.com/rust-lang/rust/issues/56898>.
let mut iter = mac_call.mac.args.tokens.iter();
while let Some(token) = iter.next() {
if let TokenTree::Token(token, _) = token
&& let TokenKind::Ident(kw::Fn, _) = token.kind
&& let Some(TokenTree::Token(ident, _)) = iter.peek()
&& let TokenKind::Ident(sym::main, _) = ident.kind
&& let Some(TokenTree::Delimited(.., Delimiter::Parenthesis, _)) = {
iter.next();
iter.peek()
}
{
info.has_main_fn = true;
break;
}
}
}
}
StmtKind::Expr(ref expr) => {
if matches!(expr.kind, ast::ExprKind::Err(_)) {
@ -421,35 +440,7 @@ fn parse_source(source: &str, crate_name: &Option<&str>) -> Result<ParseSourceIn
}
has_non_items = true;
}
// We assume that the macro calls will expand to item(s) even though they could
// expand to statements and expressions. And the simple fact that we're trying
// to retrieve a `main` function inside it is a terrible idea.
StmtKind::MacCall(ref mac_call) => {
if info.has_main_fn {
continue;
}
let mut iter = mac_call.mac.args.tokens.iter();
while let Some(token) = iter.next() {
if let TokenTree::Token(token, _) = token
&& let TokenKind::Ident(name, _) = token.kind
&& name == kw::Fn
&& let Some(TokenTree::Token(fn_token, _)) = iter.peek()
&& let TokenKind::Ident(fn_name, _) = fn_token.kind
&& fn_name == sym::main
&& let Some(TokenTree::Delimited(_, _, Delimiter::Parenthesis, _)) = {
iter.next();
iter.peek()
}
{
info.has_main_fn = true;
break;
}
}
}
_ => {
has_non_items = true;
}
StmtKind::Let(_) | StmtKind::Semi(_) | StmtKind::Empty => has_non_items = true,
}
// Weirdly enough, the `Stmt` span doesn't include its attributes, so we need to