Skip to content

Commit

Permalink
Cleanup dead code in hir::map::blocks.
Browse files Browse the repository at this point in the history
  • Loading branch information
@cjgillot
cjgillot committed Oct 19, 2021
1 parent c2452de commit 05eb6f3
Showing 1 changed file with 14 additions and 172 deletions.
186 changes: 14 additions & 172 deletions compiler/rustc_middle/src/hir/map/blocks.rs
View file
Expand Up @@ -11,12 +11,9 @@
//! nested within a uniquely determined `FnLike`), and users can ask
//! for the `Code` associated with a particular NodeId.

use crate::hir::map::Map;
use rustc_hir as hir;
use rustc_hir::intravisit::FnKind;
use rustc_hir::{Expr, FnDecl, Node};
use rustc_span::symbol::Ident;
use rustc_span::Span;
use rustc_hir::Node;

/// An FnLikeNode is a Node that is like a fn, in that it has a decl
/// and a body (as well as a NodeId, a span, etc).
Expand All @@ -33,139 +30,21 @@ pub struct FnLikeNode<'a> {
node: Node<'a>,
}

/// MaybeFnLike wraps a method that indicates if an object
/// corresponds to some FnLikeNode.
trait MaybeFnLike {
fn is_fn_like(&self) -> bool;
}

impl MaybeFnLike for hir::Item<'_> {
fn is_fn_like(&self) -> bool {
matches!(self.kind, hir::ItemKind::Fn(..))
}
}

impl MaybeFnLike for hir::ImplItem<'_> {
fn is_fn_like(&self) -> bool {
matches!(self.kind, hir::ImplItemKind::Fn(..))
}
}

impl MaybeFnLike for hir::TraitItem<'_> {
fn is_fn_like(&self) -> bool {
matches!(self.kind, hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(_)))
}
}

impl MaybeFnLike for hir::Expr<'_> {
fn is_fn_like(&self) -> bool {
matches!(self.kind, hir::ExprKind::Closure(..))
}
}

/// Carries either an FnLikeNode or an Expr, as these are the two
/// constructs that correspond to "code" (as in, something from which
/// we can construct a control-flow graph).
#[derive(Copy, Clone)]
pub enum Code<'a> {
FnLike(FnLikeNode<'a>),
Expr(&'a Expr<'a>),
}

impl<'a> Code<'a> {
pub fn id(&self) -> hir::HirId {
match *self {
Code::FnLike(node) => node.id(),
Code::Expr(block) => block.hir_id,
}
}

/// Attempts to construct a Code from presumed FnLike or Expr node input.
pub fn from_node(map: &Map<'a>, id: hir::HirId) -> Option<Code<'a>> {
match map.get(id) {
Node::Block(_) => {
// Use the parent, hopefully an expression node.
Code::from_node(map, map.get_parent_node(id))
}
Node::Expr(expr) => Some(Code::Expr(expr)),
node => FnLikeNode::from_node(node).map(Code::FnLike),
}
}
}

/// These are all the components one can extract from a fn item for
/// use when implementing FnLikeNode operations.
struct ItemFnParts<'a> {
ident: Ident,
decl: &'a hir::FnDecl<'a>,
header: hir::FnHeader,
vis: &'a hir::Visibility<'a>,
generics: &'a hir::Generics<'a>,
body: hir::BodyId,
id: hir::HirId,
span: Span,
}

/// These are all the components one can extract from a closure expr
/// for use when implementing FnLikeNode operations.
struct ClosureParts<'a> {
decl: &'a FnDecl<'a>,
body: hir::BodyId,
id: hir::HirId,
span: Span,
}

impl<'a> ClosureParts<'a> {
fn new(d: &'a FnDecl<'a>, b: hir::BodyId, id: hir::HirId, s: Span) -> Self {
ClosureParts { decl: d, body: b, id, span: s }
}
}

impl<'a> FnLikeNode<'a> {
/// Attempts to construct a FnLikeNode from presumed FnLike node input.
pub fn from_node(node: Node<'_>) -> Option<FnLikeNode<'_>> {
let fn_like = match node {
Node::Item(item) => item.is_fn_like(),
Node::TraitItem(tm) => tm.is_fn_like(),
Node::ImplItem(it) => it.is_fn_like(),
Node::Expr(e) => e.is_fn_like(),
Node::Item(item) => matches!(item.kind, hir::ItemKind::Fn(..)),
Node::TraitItem(tm) => {
matches!(tm.kind, hir::TraitItemKind::Fn(_, hir::TraitFn::Provided(_)))
}
Node::ImplItem(it) => matches!(it.kind, hir::ImplItemKind::Fn(..)),
Node::Expr(e) => matches!(e.kind, hir::ExprKind::Closure(..)),
_ => false,
};
fn_like.then_some(FnLikeNode { node })
}

pub fn body(self) -> hir::BodyId {
self.handle(
|i: ItemFnParts<'a>| i.body,
|_, _, _: &'a hir::FnSig<'a>, _, body: hir::BodyId, _| body,
|c: ClosureParts<'a>| c.body,
)
}

pub fn decl(self) -> &'a FnDecl<'a> {
self.handle(
|i: ItemFnParts<'a>| &*i.decl,
|_, _, sig: &'a hir::FnSig<'a>, _, _, _| &sig.decl,
|c: ClosureParts<'a>| c.decl,
)
}

pub fn span(self) -> Span {
self.handle(
|i: ItemFnParts<'_>| i.span,
|_, _, _: &'a hir::FnSig<'a>, _, _, span| span,
|c: ClosureParts<'_>| c.span,
)
}

pub fn id(self) -> hir::HirId {
self.handle(
|i: ItemFnParts<'_>| i.id,
|id, _, _: &'a hir::FnSig<'a>, _, _, _| id,
|c: ClosureParts<'_>| c.id,
)
}

pub fn constness(self) -> hir::Constness {
self.kind().header().map_or(hir::Constness::NotConst, |header| header.constness)
}
Expand All @@ -174,63 +53,26 @@ impl<'a> FnLikeNode<'a> {
self.kind().header().map_or(hir::IsAsync::NotAsync, |header| header.asyncness)
}

pub fn unsafety(self) -> hir::Unsafety {
self.kind().header().map_or(hir::Unsafety::Normal, |header| header.unsafety)
}

pub fn kind(self) -> FnKind<'a> {
let item = |p: ItemFnParts<'a>| -> FnKind<'a> {
FnKind::ItemFn(p.ident, p.generics, p.header, p.vis)
};
let closure = |_: ClosureParts<'a>| FnKind::Closure;
let method =
|_, ident: Ident, sig: &'a hir::FnSig<'a>, vis, _, _| FnKind::Method(ident, sig, vis);
self.handle(item, method, closure)
}

fn handle<A, I, M, C>(self, item_fn: I, method: M, closure: C) -> A
where
I: FnOnce(ItemFnParts<'a>) -> A,
M: FnOnce(
hir::HirId,
Ident,
&'a hir::FnSig<'a>,
Option<&'a hir::Visibility<'a>>,
hir::BodyId,
Span,
) -> A,
C: FnOnce(ClosureParts<'a>) -> A,
{
match self.node {
Node::Item(i) => match i.kind {
hir::ItemKind::Fn(ref sig, ref generics, block) => item_fn(ItemFnParts {
id: i.hir_id(),
ident: i.ident,
decl: &sig.decl,
body: block,
vis: &i.vis,
span: i.span,
header: sig.header,
generics,
}),
hir::ItemKind::Fn(ref sig, ref generics, _) => {
FnKind::ItemFn(i.ident, generics, sig.header, &i.vis)
}
_ => bug!("item FnLikeNode that is not fn-like"),
},
Node::TraitItem(ti) => match ti.kind {
hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
method(ti.hir_id(), ti.ident, sig, None, body, ti.span)
hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(_)) => {
FnKind::Method(ti.ident, sig, None)
}
_ => bug!("trait method FnLikeNode that is not fn-like"),
},
Node::ImplItem(ii) => match ii.kind {
hir::ImplItemKind::Fn(ref sig, body) => {
method(ii.hir_id(), ii.ident, sig, Some(&ii.vis), body, ii.span)
}
hir::ImplItemKind::Fn(ref sig, _) => FnKind::Method(ii.ident, sig, Some(&ii.vis)),
_ => bug!("impl method FnLikeNode that is not fn-like"),
},
Node::Expr(e) => match e.kind {
hir::ExprKind::Closure(_, ref decl, block, _fn_decl_span, _gen) => {
closure(ClosureParts::new(&decl, block, e.hir_id, e.span))
}
hir::ExprKind::Closure(..) => FnKind::Closure,
_ => bug!("expr FnLikeNode that is not fn-like"),
},
_ => bug!("other FnLikeNode that is not fn-like"),
Expand Down

0 comments on commit 05eb6f3

Please sign in to comment.