16cd84ee22
add suggestion applicabilities to librustc and libsyntax A down payment on #50723. Interested in feedback on whether my `MaybeIncorrect` vs. `MachineApplicable` judgement calls are well-calibrated (and that we have a consensus on what this means). r? @Manishearth cc @killercup @estebank
1579 lines
64 KiB
Rust
1579 lines
64 KiB
Rust
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use ast::{self, Block, Ident, NodeId, PatKind, Path};
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use ast::{MacStmtStyle, StmtKind, ItemKind};
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use attr::{self, HasAttrs};
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use codemap::{ExpnInfo, NameAndSpan, MacroBang, MacroAttribute, dummy_spanned, respan};
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use config::{is_test_or_bench, StripUnconfigured};
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use errors::{Applicability, FatalError};
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use ext::base::*;
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use ext::derive::{add_derived_markers, collect_derives};
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use ext::hygiene::{self, Mark, SyntaxContext};
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use ext::placeholders::{placeholder, PlaceholderExpander};
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use feature_gate::{self, Features, GateIssue, is_builtin_attr, emit_feature_err};
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use fold;
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use fold::*;
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use parse::{DirectoryOwnership, PResult, ParseSess};
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use parse::token::{self, Token};
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use parse::parser::Parser;
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use ptr::P;
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use symbol::Symbol;
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use symbol::keywords;
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use syntax_pos::{Span, DUMMY_SP, FileName};
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use syntax_pos::hygiene::ExpnFormat;
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use tokenstream::{TokenStream, TokenTree};
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use util::small_vector::SmallVector;
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use visit::{self, Visitor};
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use std::collections::HashMap;
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use std::fs::File;
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use std::io::Read;
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use std::mem;
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use std::rc::Rc;
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use std::path::PathBuf;
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macro_rules! expansions {
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($($kind:ident: $ty:ty [$($vec:ident, $ty_elt:ty)*], $kind_name:expr, .$make:ident,
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$(.$fold:ident)* $(lift .$fold_elt:ident)*,
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$(.$visit:ident)* $(lift .$visit_elt:ident)*;)*) => {
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#[derive(Copy, Clone, PartialEq, Eq)]
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pub enum ExpansionKind { OptExpr, $( $kind, )* }
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pub enum Expansion { OptExpr(Option<P<ast::Expr>>), $( $kind($ty), )* }
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impl ExpansionKind {
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pub fn name(self) -> &'static str {
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match self {
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ExpansionKind::OptExpr => "expression",
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$( ExpansionKind::$kind => $kind_name, )*
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}
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}
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fn make_from<'a>(self, result: Box<MacResult + 'a>) -> Option<Expansion> {
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match self {
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ExpansionKind::OptExpr => result.make_expr().map(Some).map(Expansion::OptExpr),
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$( ExpansionKind::$kind => result.$make().map(Expansion::$kind), )*
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}
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}
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}
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impl Expansion {
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pub fn make_opt_expr(self) -> Option<P<ast::Expr>> {
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match self {
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Expansion::OptExpr(expr) => expr,
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_ => panic!("Expansion::make_* called on the wrong kind of expansion"),
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}
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}
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$( pub fn $make(self) -> $ty {
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match self {
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Expansion::$kind(ast) => ast,
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_ => panic!("Expansion::make_* called on the wrong kind of expansion"),
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}
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} )*
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pub fn fold_with<F: Folder>(self, folder: &mut F) -> Self {
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use self::Expansion::*;
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match self {
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OptExpr(expr) => OptExpr(expr.and_then(|expr| folder.fold_opt_expr(expr))),
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$($( $kind(ast) => $kind(folder.$fold(ast)), )*)*
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$($( $kind(ast) => {
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$kind(ast.into_iter().flat_map(|ast| folder.$fold_elt(ast)).collect())
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}, )*)*
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}
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}
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pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
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match *self {
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Expansion::OptExpr(Some(ref expr)) => visitor.visit_expr(expr),
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Expansion::OptExpr(None) => {}
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$($( Expansion::$kind(ref ast) => visitor.$visit(ast), )*)*
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$($( Expansion::$kind(ref ast) => for ast in &ast[..] {
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visitor.$visit_elt(ast);
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}, )*)*
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}
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}
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}
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impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
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fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
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self.expand(Expansion::OptExpr(Some(expr))).make_opt_expr()
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}
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$($(fn $fold(&mut self, node: $ty) -> $ty {
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self.expand(Expansion::$kind(node)).$make()
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})*)*
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$($(fn $fold_elt(&mut self, node: $ty_elt) -> $ty {
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self.expand(Expansion::$kind(SmallVector::one(node))).$make()
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})*)*
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}
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impl<'a> MacResult for ::ext::tt::macro_rules::ParserAnyMacro<'a> {
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$(fn $make(self: Box<::ext::tt::macro_rules::ParserAnyMacro<'a>>) -> Option<$ty> {
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Some(self.make(ExpansionKind::$kind).$make())
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})*
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}
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}
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}
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expansions! {
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Expr: P<ast::Expr> [], "expression", .make_expr, .fold_expr, .visit_expr;
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Pat: P<ast::Pat> [], "pattern", .make_pat, .fold_pat, .visit_pat;
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Ty: P<ast::Ty> [], "type", .make_ty, .fold_ty, .visit_ty;
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Stmts: SmallVector<ast::Stmt> [SmallVector, ast::Stmt],
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"statement", .make_stmts, lift .fold_stmt, lift .visit_stmt;
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Items: SmallVector<P<ast::Item>> [SmallVector, P<ast::Item>],
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"item", .make_items, lift .fold_item, lift .visit_item;
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TraitItems: SmallVector<ast::TraitItem> [SmallVector, ast::TraitItem],
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"trait item", .make_trait_items, lift .fold_trait_item, lift .visit_trait_item;
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ImplItems: SmallVector<ast::ImplItem> [SmallVector, ast::ImplItem],
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"impl item", .make_impl_items, lift .fold_impl_item, lift .visit_impl_item;
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ForeignItems: SmallVector<ast::ForeignItem> [SmallVector, ast::ForeignItem],
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"foreign item", .make_foreign_items, lift .fold_foreign_item, lift .visit_foreign_item;
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}
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impl ExpansionKind {
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fn dummy(self, span: Span) -> Option<Expansion> {
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self.make_from(DummyResult::any(span))
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}
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fn expect_from_annotatables<I: IntoIterator<Item = Annotatable>>(self, items: I) -> Expansion {
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let mut items = items.into_iter();
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match self {
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ExpansionKind::Items =>
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Expansion::Items(items.map(Annotatable::expect_item).collect()),
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ExpansionKind::ImplItems =>
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Expansion::ImplItems(items.map(Annotatable::expect_impl_item).collect()),
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ExpansionKind::TraitItems =>
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Expansion::TraitItems(items.map(Annotatable::expect_trait_item).collect()),
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ExpansionKind::ForeignItems =>
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Expansion::ForeignItems(items.map(Annotatable::expect_foreign_item).collect()),
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ExpansionKind::Stmts => Expansion::Stmts(items.map(Annotatable::expect_stmt).collect()),
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ExpansionKind::Expr => Expansion::Expr(
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items.next().expect("expected exactly one expression").expect_expr()
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),
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ExpansionKind::OptExpr =>
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Expansion::OptExpr(items.next().map(Annotatable::expect_expr)),
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ExpansionKind::Pat | ExpansionKind::Ty =>
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panic!("patterns and types aren't annotatable"),
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}
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}
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}
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fn macro_bang_format(path: &ast::Path) -> ExpnFormat {
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// We don't want to format a path using pretty-printing,
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// `format!("{}", path)`, because that tries to insert
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// line-breaks and is slow.
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let mut path_str = String::with_capacity(64);
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for (i, segment) in path.segments.iter().enumerate() {
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if i != 0 {
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path_str.push_str("::");
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}
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if segment.ident.name != keywords::CrateRoot.name() &&
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segment.ident.name != keywords::DollarCrate.name()
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{
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path_str.push_str(&segment.ident.as_str())
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}
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}
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MacroBang(Symbol::intern(&path_str))
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}
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pub struct Invocation {
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pub kind: InvocationKind,
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expansion_kind: ExpansionKind,
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pub expansion_data: ExpansionData,
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}
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pub enum InvocationKind {
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Bang {
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mac: ast::Mac,
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ident: Option<Ident>,
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span: Span,
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},
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Attr {
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attr: Option<ast::Attribute>,
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traits: Vec<Path>,
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item: Annotatable,
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},
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Derive {
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path: Path,
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item: Annotatable,
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},
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}
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impl Invocation {
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fn span(&self) -> Span {
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match self.kind {
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InvocationKind::Bang { span, .. } => span,
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InvocationKind::Attr { attr: Some(ref attr), .. } => attr.span,
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InvocationKind::Attr { attr: None, .. } => DUMMY_SP,
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InvocationKind::Derive { ref path, .. } => path.span,
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}
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}
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}
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pub struct MacroExpander<'a, 'b:'a> {
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pub cx: &'a mut ExtCtxt<'b>,
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monotonic: bool, // c.f. `cx.monotonic_expander()`
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}
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impl<'a, 'b> MacroExpander<'a, 'b> {
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pub fn new(cx: &'a mut ExtCtxt<'b>, monotonic: bool) -> Self {
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MacroExpander { cx: cx, monotonic: monotonic }
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}
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pub fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
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let mut module = ModuleData {
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mod_path: vec![Ident::from_str(&self.cx.ecfg.crate_name)],
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directory: match self.cx.codemap().span_to_unmapped_path(krate.span) {
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FileName::Real(path) => path,
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other => PathBuf::from(other.to_string()),
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},
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};
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module.directory.pop();
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self.cx.root_path = module.directory.clone();
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self.cx.current_expansion.module = Rc::new(module);
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self.cx.current_expansion.crate_span = Some(krate.span);
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let orig_mod_span = krate.module.inner;
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let krate_item = Expansion::Items(SmallVector::one(P(ast::Item {
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attrs: krate.attrs,
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span: krate.span,
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node: ast::ItemKind::Mod(krate.module),
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ident: keywords::Invalid.ident(),
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id: ast::DUMMY_NODE_ID,
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vis: respan(krate.span.shrink_to_lo(), ast::VisibilityKind::Public),
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tokens: None,
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})));
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match self.expand(krate_item).make_items().pop().map(P::into_inner) {
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Some(ast::Item { attrs, node: ast::ItemKind::Mod(module), .. }) => {
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krate.attrs = attrs;
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krate.module = module;
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},
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None => {
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// Resolution failed so we return an empty expansion
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krate.attrs = vec![];
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krate.module = ast::Mod {
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inner: orig_mod_span,
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items: vec![],
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};
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},
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_ => unreachable!(),
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};
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self.cx.trace_macros_diag();
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krate
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}
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// Fully expand all the invocations in `expansion`.
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fn expand(&mut self, expansion: Expansion) -> Expansion {
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let orig_expansion_data = self.cx.current_expansion.clone();
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self.cx.current_expansion.depth = 0;
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let (expansion, mut invocations) = self.collect_invocations(expansion, &[]);
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self.resolve_imports();
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invocations.reverse();
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let mut expansions = Vec::new();
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let mut derives = HashMap::new();
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let mut undetermined_invocations = Vec::new();
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let (mut progress, mut force) = (false, !self.monotonic);
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loop {
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let mut invoc = if let Some(invoc) = invocations.pop() {
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invoc
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} else {
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self.resolve_imports();
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if undetermined_invocations.is_empty() { break }
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invocations = mem::replace(&mut undetermined_invocations, Vec::new());
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force = !mem::replace(&mut progress, false);
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continue
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};
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let scope =
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if self.monotonic { invoc.expansion_data.mark } else { orig_expansion_data.mark };
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let ext = match self.cx.resolver.resolve_invoc(&mut invoc, scope, force) {
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Ok(ext) => Some(ext),
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Err(Determinacy::Determined) => None,
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Err(Determinacy::Undetermined) => {
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undetermined_invocations.push(invoc);
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continue
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}
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};
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progress = true;
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let ExpansionData { depth, mark, .. } = invoc.expansion_data;
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self.cx.current_expansion = invoc.expansion_data.clone();
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self.cx.current_expansion.mark = scope;
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// FIXME(jseyfried): Refactor out the following logic
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let (expansion, new_invocations) = if let Some(ext) = ext {
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if let Some(ext) = ext {
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let dummy = invoc.expansion_kind.dummy(invoc.span()).unwrap();
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let expansion = self.expand_invoc(invoc, &*ext).unwrap_or(dummy);
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self.collect_invocations(expansion, &[])
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} else if let InvocationKind::Attr { attr: None, traits, item } = invoc.kind {
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if !item.derive_allowed() {
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let attr = attr::find_by_name(item.attrs(), "derive")
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.expect("`derive` attribute should exist");
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let span = attr.span;
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let mut err = self.cx.mut_span_err(span,
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"`derive` may only be applied to \
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structs, enums and unions");
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if let ast::AttrStyle::Inner = attr.style {
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let trait_list = traits.iter()
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.map(|t| format!("{}", t)).collect::<Vec<_>>();
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let suggestion = format!("#[derive({})]", trait_list.join(", "));
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err.span_suggestion_with_applicability(
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span, "try an outer attribute", suggestion,
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// We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT
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Applicability::MaybeIncorrect
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);
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}
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err.emit();
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}
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let item = self.fully_configure(item)
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.map_attrs(|mut attrs| { attrs.retain(|a| a.path != "derive"); attrs });
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let item_with_markers =
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add_derived_markers(&mut self.cx, item.span(), &traits, item.clone());
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let derives = derives.entry(invoc.expansion_data.mark).or_insert_with(Vec::new);
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for path in &traits {
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let mark = Mark::fresh(self.cx.current_expansion.mark);
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derives.push(mark);
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let item = match self.cx.resolver.resolve_macro(
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Mark::root(), path, MacroKind::Derive, false) {
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Ok(ext) => match *ext {
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BuiltinDerive(..) => item_with_markers.clone(),
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_ => item.clone(),
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},
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_ => item.clone(),
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};
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invocations.push(Invocation {
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kind: InvocationKind::Derive { path: path.clone(), item: item },
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expansion_kind: invoc.expansion_kind,
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expansion_data: ExpansionData {
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mark,
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..invoc.expansion_data.clone()
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},
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});
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}
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let expansion = invoc.expansion_kind
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.expect_from_annotatables(::std::iter::once(item_with_markers));
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self.collect_invocations(expansion, derives)
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} else {
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unreachable!()
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}
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} else {
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self.collect_invocations(invoc.expansion_kind.dummy(invoc.span()).unwrap(), &[])
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};
|
||
|
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if expansions.len() < depth {
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expansions.push(Vec::new());
|
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}
|
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expansions[depth - 1].push((mark, expansion));
|
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if !self.cx.ecfg.single_step {
|
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invocations.extend(new_invocations.into_iter().rev());
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}
|
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}
|
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self.cx.current_expansion = orig_expansion_data;
|
||
|
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let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic);
|
||
while let Some(expansions) = expansions.pop() {
|
||
for (mark, expansion) in expansions.into_iter().rev() {
|
||
let derives = derives.remove(&mark).unwrap_or_else(Vec::new);
|
||
placeholder_expander.add(NodeId::placeholder_from_mark(mark), expansion, derives);
|
||
}
|
||
}
|
||
|
||
expansion.fold_with(&mut placeholder_expander)
|
||
}
|
||
|
||
fn resolve_imports(&mut self) {
|
||
if self.monotonic {
|
||
let err_count = self.cx.parse_sess.span_diagnostic.err_count();
|
||
self.cx.resolver.resolve_imports();
|
||
self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count;
|
||
}
|
||
}
|
||
|
||
fn collect_invocations(&mut self, expansion: Expansion, derives: &[Mark])
|
||
-> (Expansion, Vec<Invocation>) {
|
||
let result = {
|
||
let mut collector = InvocationCollector {
|
||
cfg: StripUnconfigured {
|
||
should_test: self.cx.ecfg.should_test,
|
||
sess: self.cx.parse_sess,
|
||
features: self.cx.ecfg.features,
|
||
},
|
||
cx: self.cx,
|
||
invocations: Vec::new(),
|
||
monotonic: self.monotonic,
|
||
};
|
||
(expansion.fold_with(&mut collector), collector.invocations)
|
||
};
|
||
|
||
if self.monotonic {
|
||
let err_count = self.cx.parse_sess.span_diagnostic.err_count();
|
||
let mark = self.cx.current_expansion.mark;
|
||
self.cx.resolver.visit_expansion(mark, &result.0, derives);
|
||
self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count;
|
||
}
|
||
|
||
result
|
||
}
|
||
|
||
fn fully_configure(&mut self, item: Annotatable) -> Annotatable {
|
||
let mut cfg = StripUnconfigured {
|
||
should_test: self.cx.ecfg.should_test,
|
||
sess: self.cx.parse_sess,
|
||
features: self.cx.ecfg.features,
|
||
};
|
||
// Since the item itself has already been configured by the InvocationCollector,
|
||
// we know that fold result vector will contain exactly one element
|
||
match item {
|
||
Annotatable::Item(item) => {
|
||
Annotatable::Item(cfg.fold_item(item).pop().unwrap())
|
||
}
|
||
Annotatable::TraitItem(item) => {
|
||
Annotatable::TraitItem(item.map(|item| cfg.fold_trait_item(item).pop().unwrap()))
|
||
}
|
||
Annotatable::ImplItem(item) => {
|
||
Annotatable::ImplItem(item.map(|item| cfg.fold_impl_item(item).pop().unwrap()))
|
||
}
|
||
Annotatable::ForeignItem(item) => {
|
||
Annotatable::ForeignItem(
|
||
item.map(|item| cfg.fold_foreign_item(item).pop().unwrap())
|
||
)
|
||
}
|
||
Annotatable::Stmt(stmt) => {
|
||
Annotatable::Stmt(stmt.map(|stmt| cfg.fold_stmt(stmt).pop().unwrap()))
|
||
}
|
||
Annotatable::Expr(expr) => {
|
||
Annotatable::Expr(cfg.fold_expr(expr))
|
||
}
|
||
}
|
||
}
|
||
|
||
fn expand_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option<Expansion> {
|
||
let result = match invoc.kind {
|
||
InvocationKind::Bang { .. } => self.expand_bang_invoc(invoc, ext)?,
|
||
InvocationKind::Attr { .. } => self.expand_attr_invoc(invoc, ext)?,
|
||
InvocationKind::Derive { .. } => self.expand_derive_invoc(invoc, ext)?,
|
||
};
|
||
|
||
if self.cx.current_expansion.depth > self.cx.ecfg.recursion_limit {
|
||
let info = self.cx.current_expansion.mark.expn_info().unwrap();
|
||
let suggested_limit = self.cx.ecfg.recursion_limit * 2;
|
||
let mut err = self.cx.struct_span_err(info.call_site,
|
||
&format!("recursion limit reached while expanding the macro `{}`",
|
||
info.callee.name()));
|
||
err.help(&format!(
|
||
"consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate",
|
||
suggested_limit));
|
||
err.emit();
|
||
self.cx.trace_macros_diag();
|
||
FatalError.raise();
|
||
}
|
||
|
||
Some(result)
|
||
}
|
||
|
||
fn expand_attr_invoc(&mut self,
|
||
invoc: Invocation,
|
||
ext: &SyntaxExtension)
|
||
-> Option<Expansion> {
|
||
let Invocation { expansion_kind: kind, .. } = invoc;
|
||
let (attr, item) = match invoc.kind {
|
||
InvocationKind::Attr { attr, item, .. } => (attr?, item),
|
||
_ => unreachable!(),
|
||
};
|
||
|
||
attr::mark_used(&attr);
|
||
invoc.expansion_data.mark.set_expn_info(ExpnInfo {
|
||
call_site: attr.span,
|
||
callee: NameAndSpan {
|
||
format: MacroAttribute(Symbol::intern(&format!("{}", attr.path))),
|
||
span: None,
|
||
allow_internal_unstable: false,
|
||
allow_internal_unsafe: false,
|
||
edition: ext.edition(),
|
||
}
|
||
});
|
||
|
||
match *ext {
|
||
MultiModifier(ref mac) => {
|
||
let meta = attr.parse_meta(self.cx.parse_sess)
|
||
.map_err(|mut e| { e.emit(); }).ok()?;
|
||
let item = mac.expand(self.cx, attr.span, &meta, item);
|
||
Some(kind.expect_from_annotatables(item))
|
||
}
|
||
MultiDecorator(ref mac) => {
|
||
let mut items = Vec::new();
|
||
let meta = attr.parse_meta(self.cx.parse_sess)
|
||
.expect("derive meta should already have been parsed");
|
||
mac.expand(self.cx, attr.span, &meta, &item, &mut |item| items.push(item));
|
||
items.push(item);
|
||
Some(kind.expect_from_annotatables(items))
|
||
}
|
||
AttrProcMacro(ref mac, ..) => {
|
||
self.gate_proc_macro_attr_item(attr.span, &item);
|
||
let item_tok = TokenTree::Token(DUMMY_SP, Token::interpolated(match item {
|
||
Annotatable::Item(item) => token::NtItem(item),
|
||
Annotatable::TraitItem(item) => token::NtTraitItem(item.into_inner()),
|
||
Annotatable::ImplItem(item) => token::NtImplItem(item.into_inner()),
|
||
Annotatable::ForeignItem(item) => token::NtForeignItem(item.into_inner()),
|
||
Annotatable::Stmt(stmt) => token::NtStmt(stmt.into_inner()),
|
||
Annotatable::Expr(expr) => token::NtExpr(expr),
|
||
})).into();
|
||
let input = self.extract_proc_macro_attr_input(attr.tokens, attr.span);
|
||
let tok_result = mac.expand(self.cx, attr.span, input, item_tok);
|
||
let res = self.parse_expansion(tok_result, kind, &attr.path, attr.span);
|
||
self.gate_proc_macro_expansion(attr.span, &res);
|
||
res
|
||
}
|
||
ProcMacroDerive(..) | BuiltinDerive(..) => {
|
||
self.cx.span_err(attr.span, &format!("`{}` is a derive mode", attr.path));
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(attr.span)
|
||
}
|
||
_ => {
|
||
let msg = &format!("macro `{}` may not be used in attributes", attr.path);
|
||
self.cx.span_err(attr.span, msg);
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(attr.span)
|
||
}
|
||
}
|
||
}
|
||
|
||
fn extract_proc_macro_attr_input(&self, tokens: TokenStream, span: Span) -> TokenStream {
|
||
let mut trees = tokens.trees();
|
||
match trees.next() {
|
||
Some(TokenTree::Delimited(_, delim)) => {
|
||
if trees.next().is_none() {
|
||
return delim.tts.into()
|
||
}
|
||
}
|
||
Some(TokenTree::Token(..)) => {}
|
||
None => return TokenStream::empty(),
|
||
}
|
||
self.cx.span_err(span, "custom attribute invocations must be \
|
||
of the form #[foo] or #[foo(..)], the macro name must only be \
|
||
followed by a delimiter token");
|
||
TokenStream::empty()
|
||
}
|
||
|
||
fn gate_proc_macro_attr_item(&self, span: Span, item: &Annotatable) {
|
||
let (kind, gate) = match *item {
|
||
Annotatable::Item(ref item) => {
|
||
match item.node {
|
||
ItemKind::Mod(_) if self.cx.ecfg.proc_macro_mod() => return,
|
||
ItemKind::Mod(_) => ("modules", "proc_macro_mod"),
|
||
_ => return,
|
||
}
|
||
}
|
||
Annotatable::TraitItem(_) => return,
|
||
Annotatable::ImplItem(_) => return,
|
||
Annotatable::ForeignItem(_) => return,
|
||
Annotatable::Stmt(_) |
|
||
Annotatable::Expr(_) if self.cx.ecfg.proc_macro_expr() => return,
|
||
Annotatable::Stmt(_) => ("statements", "proc_macro_expr"),
|
||
Annotatable::Expr(_) => ("expressions", "proc_macro_expr"),
|
||
};
|
||
emit_feature_err(
|
||
self.cx.parse_sess,
|
||
gate,
|
||
span,
|
||
GateIssue::Language,
|
||
&format!("custom attributes cannot be applied to {}", kind),
|
||
);
|
||
}
|
||
|
||
fn gate_proc_macro_expansion(&self, span: Span, expansion: &Option<Expansion>) {
|
||
if self.cx.ecfg.proc_macro_gen() {
|
||
return
|
||
}
|
||
let expansion = match expansion {
|
||
Some(expansion) => expansion,
|
||
None => return,
|
||
};
|
||
|
||
expansion.visit_with(&mut DisallowModules {
|
||
span,
|
||
parse_sess: self.cx.parse_sess,
|
||
});
|
||
|
||
struct DisallowModules<'a> {
|
||
span: Span,
|
||
parse_sess: &'a ParseSess,
|
||
}
|
||
|
||
impl<'ast, 'a> Visitor<'ast> for DisallowModules<'a> {
|
||
fn visit_item(&mut self, i: &'ast ast::Item) {
|
||
let name = match i.node {
|
||
ast::ItemKind::Mod(_) => Some("modules"),
|
||
ast::ItemKind::MacroDef(_) => Some("macro definitions"),
|
||
_ => None,
|
||
};
|
||
if let Some(name) = name {
|
||
emit_feature_err(
|
||
self.parse_sess,
|
||
"proc_macro_gen",
|
||
self.span,
|
||
GateIssue::Language,
|
||
&format!("procedural macros cannot expand to {}", name),
|
||
);
|
||
}
|
||
visit::walk_item(self, i);
|
||
}
|
||
|
||
fn visit_mac(&mut self, _mac: &'ast ast::Mac) {
|
||
// ...
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Expand a macro invocation. Returns the result of expansion.
|
||
fn expand_bang_invoc(&mut self,
|
||
invoc: Invocation,
|
||
ext: &SyntaxExtension)
|
||
-> Option<Expansion> {
|
||
let (mark, kind) = (invoc.expansion_data.mark, invoc.expansion_kind);
|
||
let (mac, ident, span) = match invoc.kind {
|
||
InvocationKind::Bang { mac, ident, span } => (mac, ident, span),
|
||
_ => unreachable!(),
|
||
};
|
||
let path = &mac.node.path;
|
||
|
||
let ident = ident.unwrap_or_else(|| keywords::Invalid.ident());
|
||
let validate_and_set_expn_info = |this: &mut Self, // arg instead of capture
|
||
def_site_span: Option<Span>,
|
||
allow_internal_unstable,
|
||
allow_internal_unsafe,
|
||
// can't infer this type
|
||
unstable_feature: Option<(Symbol, u32)>,
|
||
edition| {
|
||
|
||
// feature-gate the macro invocation
|
||
if let Some((feature, issue)) = unstable_feature {
|
||
let crate_span = this.cx.current_expansion.crate_span.unwrap();
|
||
// don't stability-check macros in the same crate
|
||
// (the only time this is null is for syntax extensions registered as macros)
|
||
if def_site_span.map_or(false, |def_span| !crate_span.contains(def_span))
|
||
&& !span.allows_unstable() && this.cx.ecfg.features.map_or(true, |feats| {
|
||
// macro features will count as lib features
|
||
!feats.declared_lib_features.iter().any(|&(feat, _)| feat == feature)
|
||
}) {
|
||
let explain = format!("macro {}! is unstable", path);
|
||
emit_feature_err(this.cx.parse_sess, &*feature.as_str(), span,
|
||
GateIssue::Library(Some(issue)), &explain);
|
||
this.cx.trace_macros_diag();
|
||
return Err(kind.dummy(span));
|
||
}
|
||
}
|
||
|
||
if ident.name != keywords::Invalid.name() {
|
||
let msg = format!("macro {}! expects no ident argument, given '{}'", path, ident);
|
||
this.cx.span_err(path.span, &msg);
|
||
this.cx.trace_macros_diag();
|
||
return Err(kind.dummy(span));
|
||
}
|
||
mark.set_expn_info(ExpnInfo {
|
||
call_site: span,
|
||
callee: NameAndSpan {
|
||
format: macro_bang_format(path),
|
||
span: def_site_span,
|
||
allow_internal_unstable,
|
||
allow_internal_unsafe,
|
||
edition,
|
||
},
|
||
});
|
||
Ok(())
|
||
};
|
||
|
||
let opt_expanded = match *ext {
|
||
DeclMacro(ref expand, def_span, edition) => {
|
||
if let Err(dummy_span) = validate_and_set_expn_info(self, def_span.map(|(_, s)| s),
|
||
false, false, None,
|
||
edition) {
|
||
dummy_span
|
||
} else {
|
||
kind.make_from(expand.expand(self.cx, span, mac.node.stream()))
|
||
}
|
||
}
|
||
|
||
NormalTT {
|
||
ref expander,
|
||
def_info,
|
||
allow_internal_unstable,
|
||
allow_internal_unsafe,
|
||
unstable_feature,
|
||
edition,
|
||
} => {
|
||
if let Err(dummy_span) = validate_and_set_expn_info(self, def_info.map(|(_, s)| s),
|
||
allow_internal_unstable,
|
||
allow_internal_unsafe,
|
||
unstable_feature,
|
||
edition) {
|
||
dummy_span
|
||
} else {
|
||
kind.make_from(expander.expand(self.cx, span, mac.node.stream()))
|
||
}
|
||
}
|
||
|
||
IdentTT(ref expander, tt_span, allow_internal_unstable) => {
|
||
if ident.name == keywords::Invalid.name() {
|
||
self.cx.span_err(path.span,
|
||
&format!("macro {}! expects an ident argument", path));
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
} else {
|
||
invoc.expansion_data.mark.set_expn_info(ExpnInfo {
|
||
call_site: span,
|
||
callee: NameAndSpan {
|
||
format: macro_bang_format(path),
|
||
span: tt_span,
|
||
allow_internal_unstable,
|
||
allow_internal_unsafe: false,
|
||
edition: hygiene::default_edition(),
|
||
}
|
||
});
|
||
|
||
let input: Vec<_> = mac.node.stream().into_trees().collect();
|
||
kind.make_from(expander.expand(self.cx, span, ident, input))
|
||
}
|
||
}
|
||
|
||
MultiDecorator(..) | MultiModifier(..) | AttrProcMacro(..) => {
|
||
self.cx.span_err(path.span,
|
||
&format!("`{}` can only be used in attributes", path));
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
}
|
||
|
||
ProcMacroDerive(..) | BuiltinDerive(..) => {
|
||
self.cx.span_err(path.span, &format!("`{}` is a derive mode", path));
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
}
|
||
|
||
ProcMacro(ref expandfun, edition) => {
|
||
if ident.name != keywords::Invalid.name() {
|
||
let msg =
|
||
format!("macro {}! expects no ident argument, given '{}'", path, ident);
|
||
self.cx.span_err(path.span, &msg);
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
} else {
|
||
self.gate_proc_macro_expansion_kind(span, kind);
|
||
invoc.expansion_data.mark.set_expn_info(ExpnInfo {
|
||
call_site: span,
|
||
callee: NameAndSpan {
|
||
format: macro_bang_format(path),
|
||
// FIXME procedural macros do not have proper span info
|
||
// yet, when they do, we should use it here.
|
||
span: None,
|
||
// FIXME probably want to follow macro_rules macros here.
|
||
allow_internal_unstable: false,
|
||
allow_internal_unsafe: false,
|
||
edition,
|
||
},
|
||
});
|
||
|
||
let tok_result = expandfun.expand(self.cx, span, mac.node.stream());
|
||
let result = self.parse_expansion(tok_result, kind, path, span);
|
||
self.gate_proc_macro_expansion(span, &result);
|
||
result
|
||
}
|
||
}
|
||
};
|
||
|
||
if opt_expanded.is_some() {
|
||
opt_expanded
|
||
} else {
|
||
let msg = format!("non-{kind} macro in {kind} position: {name}",
|
||
name = path.segments[0].ident.name, kind = kind.name());
|
||
self.cx.span_err(path.span, &msg);
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
}
|
||
}
|
||
|
||
fn gate_proc_macro_expansion_kind(&self, span: Span, kind: ExpansionKind) {
|
||
let kind = match kind {
|
||
ExpansionKind::Expr => "expressions",
|
||
ExpansionKind::OptExpr => "expressions",
|
||
ExpansionKind::Pat => "patterns",
|
||
ExpansionKind::Ty => "types",
|
||
ExpansionKind::Stmts => "statements",
|
||
ExpansionKind::Items => return,
|
||
ExpansionKind::TraitItems => return,
|
||
ExpansionKind::ImplItems => return,
|
||
ExpansionKind::ForeignItems => return,
|
||
};
|
||
if self.cx.ecfg.proc_macro_non_items() {
|
||
return
|
||
}
|
||
emit_feature_err(
|
||
self.cx.parse_sess,
|
||
"proc_macro_non_items",
|
||
span,
|
||
GateIssue::Language,
|
||
&format!("procedural macros cannot be expanded to {}", kind),
|
||
);
|
||
}
|
||
|
||
/// Expand a derive invocation. Returns the result of expansion.
|
||
fn expand_derive_invoc(&mut self,
|
||
invoc: Invocation,
|
||
ext: &SyntaxExtension)
|
||
-> Option<Expansion> {
|
||
let Invocation { expansion_kind: kind, .. } = invoc;
|
||
let (path, item) = match invoc.kind {
|
||
InvocationKind::Derive { path, item } => (path, item),
|
||
_ => unreachable!(),
|
||
};
|
||
if !item.derive_allowed() {
|
||
return None;
|
||
}
|
||
|
||
let pretty_name = Symbol::intern(&format!("derive({})", path));
|
||
let span = path.span;
|
||
let attr = ast::Attribute {
|
||
path, span,
|
||
tokens: TokenStream::empty(),
|
||
// irrelevant:
|
||
id: ast::AttrId(0), style: ast::AttrStyle::Outer, is_sugared_doc: false,
|
||
};
|
||
|
||
let mut expn_info = ExpnInfo {
|
||
call_site: span,
|
||
callee: NameAndSpan {
|
||
format: MacroAttribute(pretty_name),
|
||
span: None,
|
||
allow_internal_unstable: false,
|
||
allow_internal_unsafe: false,
|
||
edition: ext.edition(),
|
||
}
|
||
};
|
||
|
||
match *ext {
|
||
ProcMacroDerive(ref ext, ..) => {
|
||
invoc.expansion_data.mark.set_expn_info(expn_info);
|
||
let span = span.with_ctxt(self.cx.backtrace());
|
||
let dummy = ast::MetaItem { // FIXME(jseyfried) avoid this
|
||
ident: Path::from_ident(keywords::Invalid.ident()),
|
||
span: DUMMY_SP,
|
||
node: ast::MetaItemKind::Word,
|
||
};
|
||
let items = ext.expand(self.cx, span, &dummy, item);
|
||
Some(kind.expect_from_annotatables(items))
|
||
}
|
||
BuiltinDerive(func) => {
|
||
expn_info.callee.allow_internal_unstable = true;
|
||
invoc.expansion_data.mark.set_expn_info(expn_info);
|
||
let span = span.with_ctxt(self.cx.backtrace());
|
||
let mut items = Vec::new();
|
||
func(self.cx, span, &attr.meta()?, &item, &mut |a| items.push(a));
|
||
Some(kind.expect_from_annotatables(items))
|
||
}
|
||
_ => {
|
||
let msg = &format!("macro `{}` may not be used for derive attributes", attr.path);
|
||
self.cx.span_err(span, msg);
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
}
|
||
}
|
||
}
|
||
|
||
fn parse_expansion(&mut self,
|
||
toks: TokenStream,
|
||
kind: ExpansionKind,
|
||
path: &Path,
|
||
span: Span)
|
||
-> Option<Expansion> {
|
||
let mut parser = self.cx.new_parser_from_tts(&toks.into_trees().collect::<Vec<_>>());
|
||
match parser.parse_expansion(kind, false) {
|
||
Ok(expansion) => {
|
||
parser.ensure_complete_parse(path, kind.name(), span);
|
||
Some(expansion)
|
||
}
|
||
Err(mut err) => {
|
||
err.set_span(span);
|
||
err.emit();
|
||
self.cx.trace_macros_diag();
|
||
kind.dummy(span)
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
impl<'a> Parser<'a> {
|
||
pub fn parse_expansion(&mut self, kind: ExpansionKind, macro_legacy_warnings: bool)
|
||
-> PResult<'a, Expansion> {
|
||
Ok(match kind {
|
||
ExpansionKind::Items => {
|
||
let mut items = SmallVector::new();
|
||
while let Some(item) = self.parse_item()? {
|
||
items.push(item);
|
||
}
|
||
Expansion::Items(items)
|
||
}
|
||
ExpansionKind::TraitItems => {
|
||
let mut items = SmallVector::new();
|
||
while self.token != token::Eof {
|
||
items.push(self.parse_trait_item(&mut false)?);
|
||
}
|
||
Expansion::TraitItems(items)
|
||
}
|
||
ExpansionKind::ImplItems => {
|
||
let mut items = SmallVector::new();
|
||
while self.token != token::Eof {
|
||
items.push(self.parse_impl_item(&mut false)?);
|
||
}
|
||
Expansion::ImplItems(items)
|
||
}
|
||
ExpansionKind::ForeignItems => {
|
||
let mut items = SmallVector::new();
|
||
while self.token != token::Eof {
|
||
if let Some(item) = self.parse_foreign_item()? {
|
||
items.push(item);
|
||
}
|
||
}
|
||
Expansion::ForeignItems(items)
|
||
}
|
||
ExpansionKind::Stmts => {
|
||
let mut stmts = SmallVector::new();
|
||
while self.token != token::Eof &&
|
||
// won't make progress on a `}`
|
||
self.token != token::CloseDelim(token::Brace) {
|
||
if let Some(stmt) = self.parse_full_stmt(macro_legacy_warnings)? {
|
||
stmts.push(stmt);
|
||
}
|
||
}
|
||
Expansion::Stmts(stmts)
|
||
}
|
||
ExpansionKind::Expr => Expansion::Expr(self.parse_expr()?),
|
||
ExpansionKind::OptExpr => {
|
||
if self.token != token::Eof {
|
||
Expansion::OptExpr(Some(self.parse_expr()?))
|
||
} else {
|
||
Expansion::OptExpr(None)
|
||
}
|
||
},
|
||
ExpansionKind::Ty => Expansion::Ty(self.parse_ty()?),
|
||
ExpansionKind::Pat => Expansion::Pat(self.parse_pat()?),
|
||
})
|
||
}
|
||
|
||
pub fn ensure_complete_parse(&mut self, macro_path: &Path, kind_name: &str, span: Span) {
|
||
if self.token != token::Eof {
|
||
let msg = format!("macro expansion ignores token `{}` and any following",
|
||
self.this_token_to_string());
|
||
// Avoid emitting backtrace info twice.
|
||
let def_site_span = self.span.with_ctxt(SyntaxContext::empty());
|
||
let mut err = self.diagnostic().struct_span_err(def_site_span, &msg);
|
||
let msg = format!("caused by the macro expansion here; the usage \
|
||
of `{}!` is likely invalid in {} context",
|
||
macro_path, kind_name);
|
||
err.span_note(span, &msg).emit();
|
||
}
|
||
}
|
||
}
|
||
|
||
struct InvocationCollector<'a, 'b: 'a> {
|
||
cx: &'a mut ExtCtxt<'b>,
|
||
cfg: StripUnconfigured<'a>,
|
||
invocations: Vec<Invocation>,
|
||
monotonic: bool,
|
||
}
|
||
|
||
impl<'a, 'b> InvocationCollector<'a, 'b> {
|
||
fn collect(&mut self, expansion_kind: ExpansionKind, kind: InvocationKind) -> Expansion {
|
||
let mark = Mark::fresh(self.cx.current_expansion.mark);
|
||
self.invocations.push(Invocation {
|
||
kind,
|
||
expansion_kind,
|
||
expansion_data: ExpansionData {
|
||
mark,
|
||
depth: self.cx.current_expansion.depth + 1,
|
||
..self.cx.current_expansion.clone()
|
||
},
|
||
});
|
||
placeholder(expansion_kind, NodeId::placeholder_from_mark(mark))
|
||
}
|
||
|
||
fn collect_bang(&mut self, mac: ast::Mac, span: Span, kind: ExpansionKind) -> Expansion {
|
||
self.collect(kind, InvocationKind::Bang { mac: mac, ident: None, span: span })
|
||
}
|
||
|
||
fn collect_attr(&mut self,
|
||
attr: Option<ast::Attribute>,
|
||
traits: Vec<Path>,
|
||
item: Annotatable,
|
||
kind: ExpansionKind)
|
||
-> Expansion {
|
||
self.collect(kind, InvocationKind::Attr { attr, traits, item })
|
||
}
|
||
|
||
/// If `item` is an attr invocation, remove and return the macro attribute and derive traits.
|
||
fn classify_item<T>(&mut self, mut item: T) -> (Option<ast::Attribute>, Vec<Path>, T)
|
||
where T: HasAttrs,
|
||
{
|
||
let (mut attr, mut traits) = (None, Vec::new());
|
||
|
||
item = item.map_attrs(|mut attrs| {
|
||
if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs,
|
||
true) {
|
||
attr = Some(legacy_attr_invoc);
|
||
return attrs;
|
||
}
|
||
|
||
if self.cx.ecfg.proc_macro_enabled() {
|
||
attr = find_attr_invoc(&mut attrs);
|
||
}
|
||
traits = collect_derives(&mut self.cx, &mut attrs);
|
||
attrs
|
||
});
|
||
|
||
(attr, traits, item)
|
||
}
|
||
|
||
/// Alternative of `classify_item()` that ignores `#[derive]` so invocations fallthrough
|
||
/// to the unused-attributes lint (making it an error on statements and expressions
|
||
/// is a breaking change)
|
||
fn classify_nonitem<T: HasAttrs>(&mut self, mut item: T) -> (Option<ast::Attribute>, T) {
|
||
let mut attr = None;
|
||
|
||
item = item.map_attrs(|mut attrs| {
|
||
if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs,
|
||
false) {
|
||
attr = Some(legacy_attr_invoc);
|
||
return attrs;
|
||
}
|
||
|
||
if self.cx.ecfg.proc_macro_enabled() {
|
||
attr = find_attr_invoc(&mut attrs);
|
||
}
|
||
attrs
|
||
});
|
||
|
||
(attr, item)
|
||
}
|
||
|
||
fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
|
||
self.cfg.configure(node)
|
||
}
|
||
|
||
// Detect use of feature-gated or invalid attributes on macro invocations
|
||
// since they will not be detected after macro expansion.
|
||
fn check_attributes(&mut self, attrs: &[ast::Attribute]) {
|
||
let features = self.cx.ecfg.features.unwrap();
|
||
for attr in attrs.iter() {
|
||
self.check_attribute_inner(attr, features);
|
||
|
||
// macros are expanded before any lint passes so this warning has to be hardcoded
|
||
if attr.path == "derive" {
|
||
self.cx.struct_span_warn(attr.span, "`#[derive]` does nothing on macro invocations")
|
||
.note("this may become a hard error in a future release")
|
||
.emit();
|
||
}
|
||
}
|
||
}
|
||
|
||
fn check_attribute(&mut self, at: &ast::Attribute) {
|
||
let features = self.cx.ecfg.features.unwrap();
|
||
self.check_attribute_inner(at, features);
|
||
}
|
||
|
||
fn check_attribute_inner(&mut self, at: &ast::Attribute, features: &Features) {
|
||
feature_gate::check_attribute(at, self.cx.parse_sess, features);
|
||
}
|
||
}
|
||
|
||
pub fn find_attr_invoc(attrs: &mut Vec<ast::Attribute>) -> Option<ast::Attribute> {
|
||
attrs.iter()
|
||
.position(|a| !attr::is_known(a) && !is_builtin_attr(a))
|
||
.map(|i| attrs.remove(i))
|
||
}
|
||
|
||
impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
|
||
fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
|
||
let mut expr = self.cfg.configure_expr(expr).into_inner();
|
||
expr.node = self.cfg.configure_expr_kind(expr.node);
|
||
|
||
// ignore derives so they remain unused
|
||
let (attr, expr) = self.classify_nonitem(expr);
|
||
|
||
if attr.is_some() {
|
||
// collect the invoc regardless of whether or not attributes are permitted here
|
||
// expansion will eat the attribute so it won't error later
|
||
attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a));
|
||
|
||
// ExpansionKind::Expr requires the macro to emit an expression
|
||
return self.collect_attr(attr, vec![], Annotatable::Expr(P(expr)), ExpansionKind::Expr)
|
||
.make_expr();
|
||
}
|
||
|
||
if let ast::ExprKind::Mac(mac) = expr.node {
|
||
self.check_attributes(&expr.attrs);
|
||
self.collect_bang(mac, expr.span, ExpansionKind::Expr).make_expr()
|
||
} else {
|
||
P(noop_fold_expr(expr, self))
|
||
}
|
||
}
|
||
|
||
fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
|
||
let mut expr = configure!(self, expr).into_inner();
|
||
expr.node = self.cfg.configure_expr_kind(expr.node);
|
||
|
||
// ignore derives so they remain unused
|
||
let (attr, expr) = self.classify_nonitem(expr);
|
||
|
||
if attr.is_some() {
|
||
attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a));
|
||
|
||
return self.collect_attr(attr, vec![], Annotatable::Expr(P(expr)),
|
||
ExpansionKind::OptExpr)
|
||
.make_opt_expr();
|
||
}
|
||
|
||
if let ast::ExprKind::Mac(mac) = expr.node {
|
||
self.check_attributes(&expr.attrs);
|
||
self.collect_bang(mac, expr.span, ExpansionKind::OptExpr).make_opt_expr()
|
||
} else {
|
||
Some(P(noop_fold_expr(expr, self)))
|
||
}
|
||
}
|
||
|
||
fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
|
||
let pat = self.cfg.configure_pat(pat);
|
||
match pat.node {
|
||
PatKind::Mac(_) => {}
|
||
_ => return noop_fold_pat(pat, self),
|
||
}
|
||
|
||
pat.and_then(|pat| match pat.node {
|
||
PatKind::Mac(mac) => self.collect_bang(mac, pat.span, ExpansionKind::Pat).make_pat(),
|
||
_ => unreachable!(),
|
||
})
|
||
}
|
||
|
||
fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
|
||
let mut stmt = match self.cfg.configure_stmt(stmt) {
|
||
Some(stmt) => stmt,
|
||
None => return SmallVector::new(),
|
||
};
|
||
|
||
// we'll expand attributes on expressions separately
|
||
if !stmt.is_expr() {
|
||
let (attr, derives, stmt_) = if stmt.is_item() {
|
||
self.classify_item(stmt)
|
||
} else {
|
||
// ignore derives on non-item statements so it falls through
|
||
// to the unused-attributes lint
|
||
let (attr, stmt) = self.classify_nonitem(stmt);
|
||
(attr, vec![], stmt)
|
||
};
|
||
|
||
if attr.is_some() || !derives.is_empty() {
|
||
return self.collect_attr(attr, derives,
|
||
Annotatable::Stmt(P(stmt_)), ExpansionKind::Stmts)
|
||
.make_stmts();
|
||
}
|
||
|
||
stmt = stmt_;
|
||
}
|
||
|
||
if let StmtKind::Mac(mac) = stmt.node {
|
||
let (mac, style, attrs) = mac.into_inner();
|
||
self.check_attributes(&attrs);
|
||
let mut placeholder = self.collect_bang(mac, stmt.span, ExpansionKind::Stmts)
|
||
.make_stmts();
|
||
|
||
// If this is a macro invocation with a semicolon, then apply that
|
||
// semicolon to the final statement produced by expansion.
|
||
if style == MacStmtStyle::Semicolon {
|
||
if let Some(stmt) = placeholder.pop() {
|
||
placeholder.push(stmt.add_trailing_semicolon());
|
||
}
|
||
}
|
||
|
||
return placeholder;
|
||
}
|
||
|
||
// The placeholder expander gives ids to statements, so we avoid folding the id here.
|
||
let ast::Stmt { id, node, span } = stmt;
|
||
noop_fold_stmt_kind(node, self).into_iter().map(|node| {
|
||
ast::Stmt { id, node, span }
|
||
}).collect()
|
||
|
||
}
|
||
|
||
fn fold_block(&mut self, block: P<Block>) -> P<Block> {
|
||
let old_directory_ownership = self.cx.current_expansion.directory_ownership;
|
||
self.cx.current_expansion.directory_ownership = DirectoryOwnership::UnownedViaBlock;
|
||
let result = noop_fold_block(block, self);
|
||
self.cx.current_expansion.directory_ownership = old_directory_ownership;
|
||
result
|
||
}
|
||
|
||
fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
|
||
let item = configure!(self, item);
|
||
|
||
let (attr, traits, mut item) = self.classify_item(item);
|
||
if attr.is_some() || !traits.is_empty() {
|
||
let item = Annotatable::Item(item);
|
||
return self.collect_attr(attr, traits, item, ExpansionKind::Items).make_items();
|
||
}
|
||
|
||
match item.node {
|
||
ast::ItemKind::Mac(..) => {
|
||
self.check_attributes(&item.attrs);
|
||
item.and_then(|item| match item.node {
|
||
ItemKind::Mac(mac) => {
|
||
self.collect(ExpansionKind::Items, InvocationKind::Bang {
|
||
mac,
|
||
ident: Some(item.ident),
|
||
span: item.span,
|
||
}).make_items()
|
||
}
|
||
_ => unreachable!(),
|
||
})
|
||
}
|
||
ast::ItemKind::Mod(ast::Mod { inner, .. }) => {
|
||
if item.ident == keywords::Invalid.ident() {
|
||
return noop_fold_item(item, self);
|
||
}
|
||
|
||
let orig_directory_ownership = self.cx.current_expansion.directory_ownership;
|
||
let mut module = (*self.cx.current_expansion.module).clone();
|
||
module.mod_path.push(item.ident);
|
||
|
||
// Detect if this is an inline module (`mod m { ... }` as opposed to `mod m;`).
|
||
// In the non-inline case, `inner` is never the dummy span (c.f. `parse_item_mod`).
|
||
// Thus, if `inner` is the dummy span, we know the module is inline.
|
||
let inline_module = item.span.contains(inner) || inner == DUMMY_SP;
|
||
|
||
if inline_module {
|
||
if let Some(path) = attr::first_attr_value_str_by_name(&item.attrs, "path") {
|
||
self.cx.current_expansion.directory_ownership =
|
||
DirectoryOwnership::Owned { relative: None };
|
||
module.directory.push(&*path.as_str());
|
||
} else {
|
||
module.directory.push(&*item.ident.as_str());
|
||
}
|
||
} else {
|
||
let path = self.cx.parse_sess.codemap().span_to_unmapped_path(inner);
|
||
let mut path = match path {
|
||
FileName::Real(path) => path,
|
||
other => PathBuf::from(other.to_string()),
|
||
};
|
||
let directory_ownership = match path.file_name().unwrap().to_str() {
|
||
Some("mod.rs") => DirectoryOwnership::Owned { relative: None },
|
||
Some(_) => DirectoryOwnership::Owned {
|
||
relative: Some(item.ident),
|
||
},
|
||
None => DirectoryOwnership::UnownedViaMod(false),
|
||
};
|
||
path.pop();
|
||
module.directory = path;
|
||
self.cx.current_expansion.directory_ownership = directory_ownership;
|
||
}
|
||
|
||
let orig_module =
|
||
mem::replace(&mut self.cx.current_expansion.module, Rc::new(module));
|
||
let result = noop_fold_item(item, self);
|
||
self.cx.current_expansion.module = orig_module;
|
||
self.cx.current_expansion.directory_ownership = orig_directory_ownership;
|
||
result
|
||
}
|
||
// Ensure that test functions are accessible from the test harness.
|
||
ast::ItemKind::Fn(..) if self.cx.ecfg.should_test => {
|
||
if item.attrs.iter().any(|attr| is_test_or_bench(attr)) {
|
||
item = item.map(|mut item| {
|
||
item.vis = respan(item.vis.span, ast::VisibilityKind::Public);
|
||
item
|
||
});
|
||
}
|
||
noop_fold_item(item, self)
|
||
}
|
||
_ => noop_fold_item(item, self),
|
||
}
|
||
}
|
||
|
||
fn fold_trait_item(&mut self, item: ast::TraitItem) -> SmallVector<ast::TraitItem> {
|
||
let item = configure!(self, item);
|
||
|
||
let (attr, traits, item) = self.classify_item(item);
|
||
if attr.is_some() || !traits.is_empty() {
|
||
let item = Annotatable::TraitItem(P(item));
|
||
return self.collect_attr(attr, traits, item, ExpansionKind::TraitItems)
|
||
.make_trait_items()
|
||
}
|
||
|
||
match item.node {
|
||
ast::TraitItemKind::Macro(mac) => {
|
||
let ast::TraitItem { attrs, span, .. } = item;
|
||
self.check_attributes(&attrs);
|
||
self.collect_bang(mac, span, ExpansionKind::TraitItems).make_trait_items()
|
||
}
|
||
_ => fold::noop_fold_trait_item(item, self),
|
||
}
|
||
}
|
||
|
||
fn fold_impl_item(&mut self, item: ast::ImplItem) -> SmallVector<ast::ImplItem> {
|
||
let item = configure!(self, item);
|
||
|
||
let (attr, traits, item) = self.classify_item(item);
|
||
if attr.is_some() || !traits.is_empty() {
|
||
let item = Annotatable::ImplItem(P(item));
|
||
return self.collect_attr(attr, traits, item, ExpansionKind::ImplItems)
|
||
.make_impl_items();
|
||
}
|
||
|
||
match item.node {
|
||
ast::ImplItemKind::Macro(mac) => {
|
||
let ast::ImplItem { attrs, span, .. } = item;
|
||
self.check_attributes(&attrs);
|
||
self.collect_bang(mac, span, ExpansionKind::ImplItems).make_impl_items()
|
||
}
|
||
_ => fold::noop_fold_impl_item(item, self),
|
||
}
|
||
}
|
||
|
||
fn fold_ty(&mut self, ty: P<ast::Ty>) -> P<ast::Ty> {
|
||
let ty = match ty.node {
|
||
ast::TyKind::Mac(_) => ty.into_inner(),
|
||
_ => return fold::noop_fold_ty(ty, self),
|
||
};
|
||
|
||
match ty.node {
|
||
ast::TyKind::Mac(mac) => self.collect_bang(mac, ty.span, ExpansionKind::Ty).make_ty(),
|
||
_ => unreachable!(),
|
||
}
|
||
}
|
||
|
||
fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
|
||
noop_fold_foreign_mod(self.cfg.configure_foreign_mod(foreign_mod), self)
|
||
}
|
||
|
||
fn fold_foreign_item(&mut self,
|
||
foreign_item: ast::ForeignItem) -> SmallVector<ast::ForeignItem> {
|
||
let (attr, traits, foreign_item) = self.classify_item(foreign_item);
|
||
|
||
let explain = if self.cx.ecfg.proc_macro_enabled() {
|
||
feature_gate::EXPLAIN_PROC_MACROS_IN_EXTERN
|
||
} else {
|
||
feature_gate::EXPLAIN_MACROS_IN_EXTERN
|
||
};
|
||
|
||
if attr.is_some() || !traits.is_empty() {
|
||
if !self.cx.ecfg.macros_in_extern_enabled() {
|
||
if let Some(ref attr) = attr {
|
||
emit_feature_err(&self.cx.parse_sess, "macros_in_extern", attr.span,
|
||
GateIssue::Language, explain);
|
||
}
|
||
}
|
||
|
||
let item = Annotatable::ForeignItem(P(foreign_item));
|
||
return self.collect_attr(attr, traits, item, ExpansionKind::ForeignItems)
|
||
.make_foreign_items();
|
||
}
|
||
|
||
if let ast::ForeignItemKind::Macro(mac) = foreign_item.node {
|
||
self.check_attributes(&foreign_item.attrs);
|
||
|
||
if !self.cx.ecfg.macros_in_extern_enabled() {
|
||
emit_feature_err(&self.cx.parse_sess, "macros_in_extern", foreign_item.span,
|
||
GateIssue::Language, explain);
|
||
}
|
||
|
||
return self.collect_bang(mac, foreign_item.span, ExpansionKind::ForeignItems)
|
||
.make_foreign_items();
|
||
}
|
||
|
||
noop_fold_foreign_item(foreign_item, self)
|
||
}
|
||
|
||
fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
|
||
match item {
|
||
ast::ItemKind::MacroDef(..) => item,
|
||
_ => noop_fold_item_kind(self.cfg.configure_item_kind(item), self),
|
||
}
|
||
}
|
||
|
||
fn fold_attribute(&mut self, at: ast::Attribute) -> Option<ast::Attribute> {
|
||
// turn `#[doc(include="filename")]` attributes into `#[doc(include(file="filename",
|
||
// contents="file contents")]` attributes
|
||
if !at.check_name("doc") {
|
||
return noop_fold_attribute(at, self);
|
||
}
|
||
|
||
if let Some(list) = at.meta_item_list() {
|
||
if !list.iter().any(|it| it.check_name("include")) {
|
||
return noop_fold_attribute(at, self);
|
||
}
|
||
|
||
let mut items = vec![];
|
||
|
||
for it in list {
|
||
if !it.check_name("include") {
|
||
items.push(noop_fold_meta_list_item(it, self));
|
||
continue;
|
||
}
|
||
|
||
if let Some(file) = it.value_str() {
|
||
let err_count = self.cx.parse_sess.span_diagnostic.err_count();
|
||
self.check_attribute(&at);
|
||
if self.cx.parse_sess.span_diagnostic.err_count() > err_count {
|
||
// avoid loading the file if they haven't enabled the feature
|
||
return noop_fold_attribute(at, self);
|
||
}
|
||
|
||
let mut buf = vec![];
|
||
let filename = self.cx.root_path.join(file.to_string());
|
||
|
||
match File::open(&filename).and_then(|mut f| f.read_to_end(&mut buf)) {
|
||
Ok(..) => {}
|
||
Err(e) => {
|
||
self.cx.span_err(at.span,
|
||
&format!("couldn't read {}: {}",
|
||
filename.display(),
|
||
e));
|
||
}
|
||
}
|
||
|
||
match String::from_utf8(buf) {
|
||
Ok(src) => {
|
||
// Add this input file to the code map to make it available as
|
||
// dependency information
|
||
self.cx.codemap().new_filemap_and_lines(&filename, &src);
|
||
|
||
let include_info = vec![
|
||
dummy_spanned(ast::NestedMetaItemKind::MetaItem(
|
||
attr::mk_name_value_item_str(Ident::from_str("file"),
|
||
dummy_spanned(file)))),
|
||
dummy_spanned(ast::NestedMetaItemKind::MetaItem(
|
||
attr::mk_name_value_item_str(Ident::from_str("contents"),
|
||
dummy_spanned(Symbol::intern(&src))))),
|
||
];
|
||
|
||
let include_ident = Ident::from_str("include");
|
||
let item = attr::mk_list_item(DUMMY_SP, include_ident, include_info);
|
||
items.push(dummy_spanned(ast::NestedMetaItemKind::MetaItem(item)));
|
||
}
|
||
Err(_) => {
|
||
self.cx.span_err(at.span,
|
||
&format!("{} wasn't a utf-8 file",
|
||
filename.display()));
|
||
}
|
||
}
|
||
} else {
|
||
items.push(noop_fold_meta_list_item(it, self));
|
||
}
|
||
}
|
||
|
||
let meta = attr::mk_list_item(DUMMY_SP, Ident::from_str("doc"), items);
|
||
match at.style {
|
||
ast::AttrStyle::Inner =>
|
||
Some(attr::mk_spanned_attr_inner(at.span, at.id, meta)),
|
||
ast::AttrStyle::Outer =>
|
||
Some(attr::mk_spanned_attr_outer(at.span, at.id, meta)),
|
||
}
|
||
} else {
|
||
noop_fold_attribute(at, self)
|
||
}
|
||
}
|
||
|
||
fn new_id(&mut self, id: ast::NodeId) -> ast::NodeId {
|
||
if self.monotonic {
|
||
assert_eq!(id, ast::DUMMY_NODE_ID);
|
||
self.cx.resolver.next_node_id()
|
||
} else {
|
||
id
|
||
}
|
||
}
|
||
}
|
||
|
||
pub struct ExpansionConfig<'feat> {
|
||
pub crate_name: String,
|
||
pub features: Option<&'feat Features>,
|
||
pub recursion_limit: usize,
|
||
pub trace_mac: bool,
|
||
pub should_test: bool, // If false, strip `#[test]` nodes
|
||
pub single_step: bool,
|
||
pub keep_macs: bool,
|
||
}
|
||
|
||
macro_rules! feature_tests {
|
||
($( fn $getter:ident = $field:ident, )*) => {
|
||
$(
|
||
pub fn $getter(&self) -> bool {
|
||
match self.features {
|
||
Some(&Features { $field: true, .. }) => true,
|
||
_ => false,
|
||
}
|
||
}
|
||
)*
|
||
}
|
||
}
|
||
|
||
impl<'feat> ExpansionConfig<'feat> {
|
||
pub fn default(crate_name: String) -> ExpansionConfig<'static> {
|
||
ExpansionConfig {
|
||
crate_name,
|
||
features: None,
|
||
recursion_limit: 1024,
|
||
trace_mac: false,
|
||
should_test: false,
|
||
single_step: false,
|
||
keep_macs: false,
|
||
}
|
||
}
|
||
|
||
feature_tests! {
|
||
fn enable_quotes = quote,
|
||
fn enable_asm = asm,
|
||
fn enable_global_asm = global_asm,
|
||
fn enable_log_syntax = log_syntax,
|
||
fn enable_concat_idents = concat_idents,
|
||
fn enable_trace_macros = trace_macros,
|
||
fn enable_allow_internal_unstable = allow_internal_unstable,
|
||
fn enable_custom_derive = custom_derive,
|
||
fn proc_macro_enabled = proc_macro,
|
||
fn macros_in_extern_enabled = macros_in_extern,
|
||
fn proc_macro_mod = proc_macro_mod,
|
||
fn proc_macro_gen = proc_macro_gen,
|
||
fn proc_macro_expr = proc_macro_expr,
|
||
fn proc_macro_non_items = proc_macro_non_items,
|
||
}
|
||
}
|
||
|
||
// A Marker adds the given mark to the syntax context.
|
||
#[derive(Debug)]
|
||
pub struct Marker(pub Mark);
|
||
|
||
impl Folder for Marker {
|
||
fn fold_ident(&mut self, mut ident: Ident) -> Ident {
|
||
ident.span = ident.span.apply_mark(self.0);
|
||
ident
|
||
}
|
||
|
||
fn new_span(&mut self, span: Span) -> Span {
|
||
span.apply_mark(self.0)
|
||
}
|
||
|
||
fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
|
||
noop_fold_mac(mac, self)
|
||
}
|
||
}
|