rust/src/libsyntax/attr/mod.rs

757 lines
24 KiB
Rust
Raw Normal View History

//! Functions dealing with attributes and meta items
mod builtin;
2019-02-07 02:33:01 +09:00
pub use builtin::{
cfg_matches, contains_feature_attr, eval_condition, find_crate_name, find_deprecation,
find_repr_attrs, find_stability, find_unwind_attr, Deprecation, InlineAttr, OptimizeAttr,
IntType, ReprAttr, RustcDeprecation, Stability, StabilityLevel, UnwindAttr,
};
2019-02-07 02:33:01 +09:00
pub use IntType::*;
pub use ReprAttr::*;
pub use StabilityLevel::*;
2019-02-07 02:33:01 +09:00
use crate::ast;
use crate::ast::{AttrId, Attribute, AttrStyle, Name, Ident, Path, PathSegment};
use crate::ast::{MetaItem, MetaItemKind, NestedMetaItem};
use crate::ast::{Lit, LitKind, Expr, Item, Local, Stmt, StmtKind, GenericParam};
2019-02-07 02:33:01 +09:00
use crate::mut_visit::visit_clobber;
2019-05-09 02:00:29 +03:00
use crate::source_map::{BytePos, Spanned, dummy_spanned};
2019-02-07 02:33:01 +09:00
use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
use crate::parse::parser::Parser;
use crate::parse::{self, ParseSess, PResult};
use crate::parse::token::{self, TokenKind};
2019-02-07 02:33:01 +09:00
use crate::ptr::P;
use crate::symbol::{sym, Symbol};
2019-02-07 02:33:01 +09:00
use crate::ThinVec;
use crate::tokenstream::{TokenStream, TokenTree, DelimSpan};
use crate::GLOBALS;
use log::debug;
use syntax_pos::{FileName, Span};
use std::iter;
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
use std::ops::DerefMut;
2014-05-20 00:07:24 -07:00
pub fn mark_used(attr: &Attribute) {
debug!("Marking {:?} as used.", attr);
GLOBALS.with(|globals| {
globals.used_attrs.lock().insert(attr.id);
});
2014-05-20 00:07:24 -07:00
}
pub fn is_used(attr: &Attribute) -> bool {
GLOBALS.with(|globals| {
globals.used_attrs.lock().contains(attr.id)
})
2014-05-20 00:07:24 -07:00
}
pub fn mark_known(attr: &Attribute) {
debug!("Marking {:?} as known.", attr);
GLOBALS.with(|globals| {
globals.known_attrs.lock().insert(attr.id);
});
}
pub fn is_known(attr: &Attribute) -> bool {
GLOBALS.with(|globals| {
globals.known_attrs.lock().contains(attr.id)
})
}
pub fn is_known_lint_tool(m_item: Ident) -> bool {
["clippy"].contains(&m_item.as_str().as_ref())
2018-07-03 13:50:48 +02:00
}
impl NestedMetaItem {
/// Returns the MetaItem if self is a NestedMetaItem::MetaItem.
pub fn meta_item(&self) -> Option<&MetaItem> {
match *self {
NestedMetaItem::MetaItem(ref item) => Some(item),
_ => None
}
}
/// Returns the Lit if self is a NestedMetaItem::Literal.
pub fn literal(&self) -> Option<&Lit> {
match *self {
NestedMetaItem::Literal(ref lit) => Some(lit),
_ => None
}
}
2019-02-08 14:53:55 +01:00
/// Returns `true` if this list item is a MetaItem with a name of `name`.
pub fn check_name(&self, name: Symbol) -> bool {
self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
}
/// For a single-segment meta-item returns its name, otherwise returns `None`.
pub fn ident(&self) -> Option<Ident> {
self.meta_item().and_then(|meta_item| meta_item.ident())
}
pub fn name_or_empty(&self) -> Symbol {
2019-05-11 17:41:37 +03:00
self.ident().unwrap_or(Ident::invalid()).name
}
/// Gets the string value if self is a MetaItem and the MetaItem is a
/// MetaItemKind::NameValue variant containing a string, otherwise None.
pub fn value_str(&self) -> Option<Symbol> {
self.meta_item().and_then(|meta_item| meta_item.value_str())
}
/// Returns a name and single literal value tuple of the MetaItem.
pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
self.meta_item().and_then(
|meta_item| meta_item.meta_item_list().and_then(
|meta_item_list| {
if meta_item_list.len() == 1 {
if let Some(ident) = meta_item.ident() {
if let Some(lit) = meta_item_list[0].literal() {
return Some((ident.name, lit));
}
}
}
None
}))
}
/// Gets a list of inner meta items from a list MetaItem type.
pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
}
/// Returns `true` if the variant is MetaItem.
pub fn is_meta_item(&self) -> bool {
self.meta_item().is_some()
}
/// Returns `true` if the variant is Literal.
pub fn is_literal(&self) -> bool {
self.literal().is_some()
}
/// Returns `true` if self is a MetaItem and the meta item is a word.
pub fn is_word(&self) -> bool {
self.meta_item().map_or(false, |meta_item| meta_item.is_word())
}
/// Returns `true` if self is a MetaItem and the meta item is a ValueString.
pub fn is_value_str(&self) -> bool {
self.value_str().is_some()
}
/// Returns `true` if self is a MetaItem and the meta item is a list.
pub fn is_meta_item_list(&self) -> bool {
self.meta_item_list().is_some()
}
}
2016-08-23 03:54:53 +00:00
impl Attribute {
/// Returns `true` if the attribute's path matches the argument. If it matches, then the
/// attribute is marked as used.
///
/// To check the attribute name without marking it used, use the `path` field directly.
pub fn check_name(&self, name: Symbol) -> bool {
let matches = self.path == name;
if matches {
mark_used(self);
}
matches
}
/// For a single-segment attribute returns its name, otherwise returns `None`.
pub fn ident(&self) -> Option<Ident> {
if self.path.segments.len() == 1 {
Some(self.path.segments[0].ident)
} else {
None
}
}
pub fn name_or_empty(&self) -> Symbol {
2019-05-11 17:41:37 +03:00
self.ident().unwrap_or(Ident::invalid()).name
}
pub fn value_str(&self) -> Option<Symbol> {
self.meta().and_then(|meta| meta.value_str())
}
pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
match self.meta() {
Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
_ => None
}
}
pub fn is_word(&self) -> bool {
self.tokens.is_empty()
}
2016-08-23 03:54:53 +00:00
pub fn is_meta_item_list(&self) -> bool {
self.meta_item_list().is_some()
}
/// Indicates if the attribute is a Value String.
pub fn is_value_str(&self) -> bool {
self.value_str().is_some()
}
}
2016-08-23 03:54:53 +00:00
impl MetaItem {
/// For a single-segment meta-item returns its name, otherwise returns `None`.
pub fn ident(&self) -> Option<Ident> {
if self.path.segments.len() == 1 {
Some(self.path.segments[0].ident)
} else {
None
}
}
pub fn name_or_empty(&self) -> Symbol {
self.ident().unwrap_or(Ident::invalid()).name
2018-01-30 14:30:39 +09:00
}
// #[attribute(name = "value")]
// ^^^^^^^^^^^^^^
pub fn name_value_literal(&self) -> Option<&Lit> {
match &self.node {
MetaItemKind::NameValue(v) => Some(v),
_ => None,
}
}
pub fn value_str(&self) -> Option<Symbol> {
match self.node {
MetaItemKind::NameValue(ref v) => {
match v.node {
LitKind::Str(ref s, _) => Some(*s),
_ => None,
}
},
_ => None
}
}
2016-08-23 03:54:53 +00:00
pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
match self.node {
MetaItemKind::List(ref l) => Some(&l[..]),
_ => None
}
}
2016-08-23 03:54:53 +00:00
pub fn is_word(&self) -> bool {
match self.node {
MetaItemKind::Word => true,
_ => false,
}
}
pub fn check_name(&self, name: Symbol) -> bool {
self.path == name
}
2016-08-23 03:54:53 +00:00
pub fn is_value_str(&self) -> bool {
self.value_str().is_some()
}
pub fn is_meta_item_list(&self) -> bool {
self.meta_item_list().is_some()
}
}
2016-08-23 03:39:04 +00:00
impl Attribute {
2019-02-08 14:53:55 +01:00
/// Extracts the MetaItem from inside this Attribute.
pub fn meta(&self) -> Option<MetaItem> {
let mut tokens = self.tokens.trees().peekable();
Some(MetaItem {
path: self.path.clone(),
node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
if tokens.peek().is_some() {
return None;
}
node
} else {
return None;
},
span: self.span,
})
}
2017-03-08 23:13:35 +00:00
pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
{
let mut parser = Parser::new(
sess,
self.tokens.clone(),
None,
false,
false,
Some("attribute"),
);
2017-03-08 23:13:35 +00:00
let result = f(&mut parser)?;
if parser.token != token::Eof {
parser.unexpected()?;
}
Ok(result)
}
pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
{
if self.tokens.is_empty() {
return Ok(Vec::new());
}
self.parse(sess, |parser| {
parser.expect(&token::OpenDelim(token::Paren))?;
let mut list = Vec::new();
while !parser.eat(&token::CloseDelim(token::Paren)) {
list.push(f(parser)?);
if !parser.eat(&token::Comma) {
parser.expect(&token::CloseDelim(token::Paren))?;
break
}
}
Ok(list)
})
}
pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
Ok(MetaItem {
path: self.path.clone(),
2017-03-08 23:13:35 +00:00
node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
span: self.span,
})
}
2019-02-08 14:53:55 +01:00
/// Converts self to a normal #[doc="foo"] comment, if it is a
/// comment like `///` or `/** */`. (Returns self unchanged for
/// non-sugared doc attributes.)
2016-08-23 03:39:04 +00:00
pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
2014-12-08 13:28:32 -05:00
F: FnOnce(&Attribute) -> T,
{
2016-11-14 12:00:25 +00:00
if self.is_sugared_doc {
let comment = self.value_str().unwrap();
let meta = mk_name_value_item_str(
Ident::with_empty_ctxt(sym::doc),
dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str()))));
let mut attr = if self.style == ast::AttrStyle::Outer {
mk_attr_outer(self.span, self.id, meta)
} else {
mk_attr_inner(self.span, self.id, meta)
};
attr.is_sugared_doc = true;
f(&attr)
} else {
2014-09-13 19:06:01 +03:00
f(self)
}
}
}
/* Constructors */
pub fn mk_name_value_item_str(ident: Ident, value: Spanned<Symbol>) -> MetaItem {
let lit_kind = LitKind::Str(value.node, ast::StrStyle::Cooked);
mk_name_value_item(ident.span.to(value.span), ident, lit_kind, value.span)
}
pub fn mk_name_value_item(span: Span, ident: Ident, lit_kind: LitKind, lit_span: Span) -> MetaItem {
let lit = Lit::from_lit_kind(lit_kind, lit_span);
MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::NameValue(lit) }
}
pub fn mk_list_item(span: Span, ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::List(items) }
}
pub fn mk_word_item(ident: Ident) -> MetaItem {
MetaItem { path: Path::from_ident(ident), span: ident.span, node: MetaItemKind::Word }
}
2018-01-30 14:30:39 +09:00
pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem {
NestedMetaItem::MetaItem(mk_word_item(ident))
}
2017-12-03 14:03:28 +01:00
pub fn mk_attr_id() -> AttrId {
use std::sync::atomic::AtomicUsize;
use std::sync::atomic::Ordering;
2017-12-03 14:03:28 +01:00
static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
2017-12-03 14:03:28 +01:00
let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
assert!(id != ::std::usize::MAX);
2014-05-20 00:07:24 -07:00
AttrId(id)
}
/// Returns an inner attribute with the given value.
pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
mk_spanned_attr_inner(span, id, item)
}
2017-08-11 00:16:18 +02:00
/// Returns an inner attribute with the given value and span.
pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
2016-11-14 12:00:25 +00:00
Attribute {
id,
2016-11-14 12:00:25 +00:00
style: ast::AttrStyle::Inner,
path: item.path,
tokens: item.node.tokens(item.span),
2016-11-14 12:00:25 +00:00
is_sugared_doc: false,
span: sp,
}
}
/// Returns an outer attribute with the given value.
pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
mk_spanned_attr_outer(span, id, item)
}
/// Returns an outer attribute with the given value and span.
pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
2016-11-14 12:00:25 +00:00
Attribute {
id,
2016-11-14 12:00:25 +00:00
style: ast::AttrStyle::Outer,
path: item.path,
tokens: item.node.tokens(item.span),
2016-11-14 12:00:25 +00:00
is_sugared_doc: false,
span: sp,
}
}
pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
let style = doc_comment_style(&text.as_str());
let lit_kind = LitKind::Str(text, ast::StrStyle::Cooked);
let lit = Lit::from_lit_kind(lit_kind, span);
2016-11-14 12:00:25 +00:00
Attribute {
id,
style,
path: Path::from_ident(Ident::with_empty_ctxt(sym::doc).with_span_pos(span)),
tokens: MetaItemKind::NameValue(lit).tokens(span),
2016-11-14 12:00:25 +00:00
is_sugared_doc: true,
span,
2016-11-14 12:00:25 +00:00
}
}
pub fn list_contains_name(items: &[NestedMetaItem], name: Symbol) -> bool {
items.iter().any(|item| {
item.check_name(name)
})
}
pub fn contains_name(attrs: &[Attribute], name: Symbol) -> bool {
2016-08-23 03:54:53 +00:00
attrs.iter().any(|item| {
item.check_name(name)
})
}
pub fn find_by_name<'a>(attrs: &'a [Attribute], name: Symbol) -> Option<&'a Attribute> {
attrs.iter().find(|attr| attr.check_name(name))
}
pub fn filter_by_name<'a>(attrs: &'a [Attribute], name: Symbol)
-> impl Iterator<Item = &'a Attribute> {
attrs.iter().filter(move |attr| attr.check_name(name))
}
pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: Symbol) -> Option<Symbol> {
attrs.iter()
.find(|at| at.check_name(name))
.and_then(|at| at.value_str())
}
impl MetaItem {
fn tokens(&self) -> TokenStream {
2018-01-30 14:30:39 +09:00
let mut idents = vec![];
let mut last_pos = BytePos(0 as u32);
for (i, segment) in self.path.segments.iter().enumerate() {
2018-01-30 14:30:39 +09:00
let is_first = i == 0;
if !is_first {
2018-04-17 15:33:39 +02:00
let mod_sep_span = Span::new(last_pos,
segment.ident.span.lo(),
segment.ident.span.ctxt());
idents.push(TokenTree::Token(mod_sep_span, token::ModSep).into());
2018-01-30 14:30:39 +09:00
}
2018-04-17 15:33:39 +02:00
idents.push(TokenTree::Token(segment.ident.span,
TokenKind::from_ast_ident(segment.ident)).into());
2018-04-17 15:33:39 +02:00
last_pos = segment.ident.span.hi();
2018-01-30 14:30:39 +09:00
}
self.node.tokens(self.span).append_to_tree_and_joint_vec(&mut idents);
TokenStream::new(idents)
}
fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
where I: Iterator<Item = TokenTree>,
{
2018-04-24 16:57:41 +02:00
// FIXME: Share code with `parse_path`.
let path = match tokens.next() {
Some(TokenTree::Token(span, token @ token::Ident(..))) |
Some(TokenTree::Token(span, token @ token::ModSep)) => 'arm: {
let mut segments = if let token::Ident(ident, _) = token {
if let Some(TokenTree::Token(_, token::ModSep)) = tokens.peek() {
tokens.next();
vec![PathSegment::from_ident(ident.with_span_pos(span))]
} else {
break 'arm Path::from_ident(ident.with_span_pos(span));
2018-01-30 14:30:39 +09:00
}
} else {
vec![PathSegment::path_root(span)]
};
loop {
if let Some(TokenTree::Token(span,
token::Ident(ident, _))) = tokens.next() {
segments.push(PathSegment::from_ident(ident.with_span_pos(span)));
} else {
return None;
}
if let Some(TokenTree::Token(_, token::ModSep)) = tokens.peek() {
tokens.next();
} else {
break;
}
2018-01-30 14:30:39 +09:00
}
let span = span.with_hi(segments.last().unwrap().ident.span.hi());
Path { span, segments }
2018-01-30 14:30:39 +09:00
}
Some(TokenTree::Token(_, token::Interpolated(nt))) => match *nt {
2018-04-24 16:57:41 +02:00
token::Nonterminal::NtIdent(ident, _) => Path::from_ident(ident),
2017-03-29 07:17:18 +00:00
token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
2018-01-30 14:30:39 +09:00
token::Nonterminal::NtPath(ref path) => path.clone(),
2017-03-29 07:17:18 +00:00
_ => return None,
2017-03-08 23:13:35 +00:00
},
_ => return None,
};
2017-07-31 23:04:34 +03:00
let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
let node = MetaItemKind::from_tokens(tokens)?;
2017-07-31 23:04:34 +03:00
let hi = match node {
MetaItemKind::NameValue(ref lit) => lit.span.hi(),
MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(path.span.hi()),
_ => path.span.hi(),
};
let span = path.span.with_hi(hi);
Some(MetaItem { path, node, span })
}
}
impl MetaItemKind {
pub fn tokens(&self, span: Span) -> TokenStream {
match *self {
MetaItemKind::Word => TokenStream::empty(),
MetaItemKind::NameValue(ref lit) => {
let mut vec = vec![TokenTree::Token(span, token::Eq).into()];
lit.tokens().append_to_tree_and_joint_vec(&mut vec);
TokenStream::new(vec)
}
MetaItemKind::List(ref list) => {
let mut tokens = Vec::new();
for (i, item) in list.iter().enumerate() {
if i > 0 {
tokens.push(TokenTree::Token(span, token::Comma).into());
}
item.tokens().append_to_tree_and_joint_vec(&mut tokens);
}
TokenTree::Delimited(
DelimSpan::from_single(span),
token::Paren,
TokenStream::new(tokens).into(),
).into()
}
}
}
fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
where I: Iterator<Item = TokenTree>,
{
let delimited = match tokens.peek().cloned() {
Some(TokenTree::Token(_, token::Eq)) => {
tokens.next();
return if let Some(TokenTree::Token(span, token)) = tokens.next() {
Lit::from_token(&token, span).ok().map(MetaItemKind::NameValue)
} else {
None
};
}
Some(TokenTree::Delimited(_, delim, ref tts)) if delim == token::Paren => {
tokens.next();
tts.clone()
}
_ => return Some(MetaItemKind::Word),
};
let mut tokens = delimited.into_trees().peekable();
let mut result = Vec::new();
while let Some(..) = tokens.peek() {
let item = NestedMetaItem::from_tokens(&mut tokens)?;
result.push(item);
match tokens.next() {
None | Some(TokenTree::Token(_, token::Comma)) => {}
_ => return None,
}
}
Some(MetaItemKind::List(result))
}
}
impl NestedMetaItem {
pub fn span(&self) -> Span {
match *self {
NestedMetaItem::MetaItem(ref item) => item.span,
NestedMetaItem::Literal(ref lit) => lit.span,
}
}
fn tokens(&self) -> TokenStream {
match *self {
NestedMetaItem::MetaItem(ref item) => item.tokens(),
NestedMetaItem::Literal(ref lit) => lit.tokens(),
}
}
fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItem>
where I: Iterator<Item = TokenTree>,
{
if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
if let Ok(lit) = Lit::from_token(&token, span) {
tokens.next();
return Some(NestedMetaItem::Literal(lit));
}
}
MetaItem::from_tokens(tokens).map(NestedMetaItem::MetaItem)
}
}
2016-05-18 07:25:44 +00:00
pub trait HasAttrs: Sized {
fn attrs(&self) -> &[ast::Attribute];
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F);
2016-05-18 07:25:44 +00:00
}
impl<T: HasAttrs> HasAttrs for Spanned<T> {
fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
self.node.visit_attrs(f);
}
}
2016-05-18 07:25:44 +00:00
impl HasAttrs for Vec<Attribute> {
fn attrs(&self) -> &[Attribute] {
self
2016-05-18 07:25:44 +00:00
}
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
2016-05-18 07:25:44 +00:00
f(self)
}
}
impl HasAttrs for ThinVec<Attribute> {
2016-05-18 07:25:44 +00:00
fn attrs(&self) -> &[Attribute] {
self
2016-05-18 07:25:44 +00:00
}
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
visit_clobber(self, |this| {
let mut vec = this.into();
f(&mut vec);
vec.into()
});
}
}
2016-05-18 07:25:44 +00:00
impl<T: HasAttrs + 'static> HasAttrs for P<T> {
fn attrs(&self) -> &[Attribute] {
(**self).attrs()
}
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
(**self).visit_attrs(f);
}
}
2016-05-18 07:25:44 +00:00
impl HasAttrs for StmtKind {
fn attrs(&self) -> &[Attribute] {
match *self {
2016-06-17 02:30:01 +00:00
StmtKind::Local(ref local) => local.attrs(),
StmtKind::Item(..) => &[],
2016-06-17 02:30:01 +00:00
StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
StmtKind::Mac(ref mac) => {
let (_, _, ref attrs) = **mac;
attrs.attrs()
}
2016-05-18 07:25:44 +00:00
}
}
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
2016-05-18 07:25:44 +00:00
match self {
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
StmtKind::Local(local) => local.visit_attrs(f),
StmtKind::Item(..) => {}
StmtKind::Expr(expr) => expr.visit_attrs(f),
StmtKind::Semi(expr) => expr.visit_attrs(f),
StmtKind::Mac(mac) => {
let (_mac, _style, attrs) = mac.deref_mut();
attrs.visit_attrs(f);
}
2016-05-18 07:25:44 +00:00
}
}
}
impl HasAttrs for Stmt {
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn attrs(&self) -> &[ast::Attribute] {
self.node.attrs()
}
fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
self.node.visit_attrs(f);
}
}
impl HasAttrs for GenericParam {
fn attrs(&self) -> &[ast::Attribute] {
2018-06-13 13:29:40 +01:00
&self.attrs
}
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
self.attrs.visit_attrs(f);
}
}
macro_rules! derive_has_attrs {
($($ty:path),*) => { $(
2016-05-18 07:25:44 +00:00
impl HasAttrs for $ty {
fn attrs(&self) -> &[Attribute] {
&self.attrs
2016-05-18 07:25:44 +00:00
}
Overhaul `syntax::fold::Folder`. This commit changes `syntax::fold::Folder` from a functional style (where most methods take a `T` and produce a new `T`) to a more imperative style (where most methods take and modify a `&mut T`), and renames it `syntax::mut_visit::MutVisitor`. The first benefit is speed. The functional style does not require any reallocations, due to the use of `P::map` and `MoveMap::move_{,flat_}map`. However, every field in the AST must be overwritten; even those fields that are unchanged are overwritten with the same value. This causes a lot of unnecessary memory writes. The imperative style reduces instruction counts by 1--3% across a wide range of workloads, particularly incremental workloads. The second benefit is conciseness; the imperative style is usually more concise. E.g. compare the old functional style: ``` fn fold_abc(&mut self, abc: ABC) { ABC { a: fold_a(abc.a), b: fold_b(abc.b), c: abc.c, } } ``` with the imperative style: ``` fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) { visit_a(a); visit_b(b); } ``` (The reductions get larger in more complex examples.) Overall, the patch removes over 200 lines of code -- even though the new code has more comments -- and a lot of the remaining lines have fewer characters. Some notes: - The old style used methods called `fold_*`. The new style mostly uses methods called `visit_*`, but there are a few methods that map a `T` to something other than a `T`, which are called `flat_map_*` (`T` maps to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s). - `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed `map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to reflect their slightly changed signatures. - Although this commit renames the `fold` module as `mut_visit`, it keeps it in the `fold.rs` file, so as not to confuse git. The next commit will rename the file.
2019-02-05 15:20:55 +11:00
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
self.attrs.visit_attrs(f);
2016-05-18 07:25:44 +00:00
}
}
)* }
}
derive_has_attrs! {
Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
2018-06-13 13:29:40 +01:00
ast::Field, ast::FieldPat, ast::Variant_
2016-05-18 07:25:44 +00:00
}
pub fn inject(mut krate: ast::Crate, parse_sess: &ParseSess, attrs: &[String]) -> ast::Crate {
for raw_attr in attrs {
let mut parser = parse::new_parser_from_source_str(
parse_sess,
FileName::cli_crate_attr_source_code(&raw_attr),
raw_attr.clone(),
);
let start_span = parser.span;
let (path, tokens) = panictry!(parser.parse_meta_item_unrestricted());
let end_span = parser.span;
if parser.token != token::Eof {
parse_sess.span_diagnostic
.span_err(start_span.to(end_span), "invalid crate attribute");
continue;
}
krate.attrs.push(Attribute {
id: mk_attr_id(),
style: AttrStyle::Inner,
path,
tokens,
is_sugared_doc: false,
span: start_span.to(end_span),
});
}
krate
}