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Factor out the two entry_point_type functions.
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They are very similar, and each one has a comment about the importance
of being kept in sync with the other. This commit removes the
duplication.
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nnethercote committed Oct 1, 2023
1 parent 373cc21 commit 7326cd9
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Showing 3 changed files with 36 additions and 42 deletions.
27 changes: 27 additions & 0 deletions compiler/rustc_ast/src/entry.rs
Original file line number Diff line number Diff line change
@@ -1,3 +1,7 @@
use crate::{attr, Attribute};
use rustc_span::symbol::sym;
use rustc_span::Symbol;

#[derive(Debug)]
pub enum EntryPointType {
None,
Expand All @@ -6,3 +10,26 @@ pub enum EntryPointType {
Start,
OtherMain, // Not an entry point, but some other function named main
}

pub fn entry_point_type(
attrs: &[Attribute],
at_root: bool,
name: Option<Symbol>,
) -> EntryPointType {
if attr::contains_name(attrs, sym::start) {
EntryPointType::Start
} else if attr::contains_name(attrs, sym::rustc_main) {
EntryPointType::RustcMainAttr
} else {
if let Some(name) = name && name == sym::main {
if at_root {
// This is a top-level function so it can be `main`.
EntryPointType::MainNamed
} else {
EntryPointType::OtherMain
}
} else {
EntryPointType::None
}
}
}
18 changes: 2 additions & 16 deletions compiler/rustc_builtin_macros/src/test_harness.rs
Original file line number Diff line number Diff line change
Expand Up @@ -169,29 +169,15 @@ impl<'a> Visitor<'a> for InnerItemLinter<'_> {
}
}

// Beware, this is duplicated in librustc_passes/entry.rs (with
// `rustc_hir::Item`), so make sure to keep them in sync.
fn entry_point_type(item: &ast::Item, at_root: bool) -> EntryPointType {
match item.kind {
ast::ItemKind::Fn(..) => {
if attr::contains_name(&item.attrs, sym::start) {
EntryPointType::Start
} else if attr::contains_name(&item.attrs, sym::rustc_main) {
EntryPointType::RustcMainAttr
} else if item.ident.name == sym::main {
if at_root {
// This is a top-level function so can be 'main'
EntryPointType::MainNamed
} else {
EntryPointType::OtherMain
}
} else {
EntryPointType::None
}
rustc_ast::entry::entry_point_type(&item.attrs, at_root, Some(item.ident.name))
}
_ => EntryPointType::None,
}
}

/// A folder used to remove any entry points (like fn main) because the harness
/// generator will provide its own
struct EntryPointCleaner<'a> {
Expand Down
33 changes: 7 additions & 26 deletions compiler/rustc_passes/src/entry.rs
Original file line number Diff line number Diff line change
Expand Up @@ -52,31 +52,6 @@ fn entry_fn(tcx: TyCtxt<'_>, (): ()) -> Option<(DefId, EntryFnType)> {
configure_main(tcx, &ctxt)
}

// Beware, this is duplicated in `librustc_builtin_macros/test_harness.rs`
// (with `ast::Item`), so make sure to keep them in sync.
// A small optimization was added so that hir::Item is fetched only when needed.
// An equivalent optimization was not applied to the duplicated code in test_harness.rs.
fn entry_point_type(ctxt: &EntryContext<'_>, id: ItemId, at_root: bool) -> EntryPointType {
let attrs = ctxt.tcx.hir().attrs(id.hir_id());
if attr::contains_name(attrs, sym::start) {
EntryPointType::Start
} else if attr::contains_name(attrs, sym::rustc_main) {
EntryPointType::RustcMainAttr
} else {
if let Some(name) = ctxt.tcx.opt_item_name(id.owner_id.to_def_id())
&& name == sym::main {
if at_root {
// This is a top-level function so can be `main`.
EntryPointType::MainNamed
} else {
EntryPointType::OtherMain
}
} else {
EntryPointType::None
}
}
}

fn attr_span_by_symbol(ctxt: &EntryContext<'_>, id: ItemId, sym: Symbol) -> Option<Span> {
let attrs = ctxt.tcx.hir().attrs(id.hir_id());
attr::find_by_name(attrs, sym).map(|attr| attr.span)
Expand All @@ -85,7 +60,13 @@ fn attr_span_by_symbol(ctxt: &EntryContext<'_>, id: ItemId, sym: Symbol) -> Opti
fn find_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
let at_root = ctxt.tcx.opt_local_parent(id.owner_id.def_id) == Some(CRATE_DEF_ID);

match entry_point_type(ctxt, id, at_root) {
let attrs = ctxt.tcx.hir().attrs(id.hir_id());
let entry_point_type = rustc_ast::entry::entry_point_type(
attrs,
at_root,
ctxt.tcx.opt_item_name(id.owner_id.to_def_id()),
);
match entry_point_type {
EntryPointType::None => {
if let Some(span) = attr_span_by_symbol(ctxt, id, sym::unix_sigpipe) {
ctxt.tcx.sess.emit_err(AttrOnlyOnMain { span, attr: sym::unix_sigpipe });
Expand Down

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