rust/src/librustc_resolve/macros.rs

270 lines
10 KiB
Rust
Raw Normal View History

// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use {Module, Resolver};
use build_reduced_graph::BuildReducedGraphVisitor;
use rustc::hir::def_id::{CRATE_DEF_INDEX, DefIndex};
use rustc::hir::map::{self, DefCollector};
2016-09-16 03:50:34 -05:00
use std::cell::Cell;
use std::rc::Rc;
2016-09-16 01:45:03 -05:00
use syntax::ast;
use syntax::errors::DiagnosticBuilder;
use syntax::ext::base::{self, Determinacy, MultiModifier, MultiDecorator};
2016-09-16 01:45:03 -05:00
use syntax::ext::base::{NormalTT, SyntaxExtension};
use syntax::ext::expand::Expansion;
2016-10-06 03:04:30 -05:00
use syntax::ext::hygiene::Mark;
use syntax::ext::tt::macro_rules;
2016-09-16 01:45:03 -05:00
use syntax::parse::token::intern;
use syntax::util::lev_distance::find_best_match_for_name;
2016-10-06 03:04:30 -05:00
use syntax_pos::Span;
#[derive(Clone)]
pub struct InvocationData<'a> {
2016-09-16 03:50:34 -05:00
pub module: Cell<Module<'a>>,
2016-10-15 22:39:52 -05:00
pub def_index: DefIndex,
// True if this expansion is in a `const_integer` position, for example `[u32; m!()]`.
// c.f. `DefCollector::visit_ast_const_integer`.
2016-10-15 22:39:52 -05:00
pub const_integer: bool,
2016-10-06 03:04:30 -05:00
// The scope in which the invocation path is resolved.
pub legacy_scope: Cell<LegacyScope<'a>>,
// The smallest scope that includes this invocation's expansion,
// or `Empty` if this invocation has not been expanded yet.
pub expansion: Cell<LegacyScope<'a>>,
}
impl<'a> InvocationData<'a> {
pub fn root(graph_root: Module<'a>) -> Self {
InvocationData {
2016-09-16 03:50:34 -05:00
module: Cell::new(graph_root),
def_index: CRATE_DEF_INDEX,
const_integer: false,
2016-10-06 03:04:30 -05:00
legacy_scope: Cell::new(LegacyScope::Empty),
expansion: Cell::new(LegacyScope::Empty),
}
}
}
2016-10-06 03:04:30 -05:00
#[derive(Copy, Clone)]
pub enum LegacyScope<'a> {
Empty,
Invocation(&'a InvocationData<'a>), // The scope of the invocation, not including its expansion
Expansion(&'a InvocationData<'a>), // The scope of the invocation, including its expansion
Binding(&'a LegacyBinding<'a>),
}
2016-10-07 19:30:24 -05:00
impl<'a> LegacyScope<'a> {
fn simplify_expansion(mut invoc: &'a InvocationData<'a>) -> Self {
while let LegacyScope::Invocation(_) = invoc.expansion.get() {
match invoc.legacy_scope.get() {
LegacyScope::Expansion(new_invoc) => invoc = new_invoc,
LegacyScope::Binding(_) => break,
scope @ _ => return scope,
}
}
LegacyScope::Expansion(invoc)
}
}
2016-10-06 03:04:30 -05:00
pub struct LegacyBinding<'a> {
pub parent: LegacyScope<'a>,
pub name: ast::Name,
2016-10-10 22:48:54 -05:00
ext: Rc<SyntaxExtension>,
pub span: Span,
2016-10-06 03:04:30 -05:00
}
impl<'a> base::Resolver for Resolver<'a> {
fn next_node_id(&mut self) -> ast::NodeId {
self.session.next_node_id()
}
fn get_module_scope(&mut self, id: ast::NodeId) -> Mark {
let mark = Mark::fresh();
let module = self.module_map[&id];
self.invocations.insert(mark, self.arenas.alloc_invocation_data(InvocationData {
2016-09-16 03:50:34 -05:00
module: Cell::new(module),
def_index: module.def_id().unwrap().index,
const_integer: false,
2016-10-06 03:04:30 -05:00
legacy_scope: Cell::new(LegacyScope::Empty),
expansion: Cell::new(LegacyScope::Empty),
2016-09-16 03:50:34 -05:00
}));
mark
}
fn visit_expansion(&mut self, mark: Mark, expansion: &Expansion) {
2016-10-06 03:04:30 -05:00
let invocation = self.invocations[&mark];
self.collect_def_ids(invocation, expansion);
self.current_module = invocation.module.get();
let mut visitor = BuildReducedGraphVisitor {
resolver: self,
legacy_scope: LegacyScope::Invocation(invocation),
expansion: mark,
2016-10-06 03:04:30 -05:00
};
expansion.visit_with(&mut visitor);
invocation.expansion.set(visitor.legacy_scope);
}
fn add_macro(&mut self, scope: Mark, mut def: ast::MacroDef, export: bool) {
if &def.ident.name.as_str() == "macro_rules" {
self.session.span_err(def.span, "user-defined macros may not be named `macro_rules`");
}
let invocation = self.invocations[&scope];
let binding = self.arenas.alloc_legacy_binding(LegacyBinding {
parent: invocation.legacy_scope.get(),
name: def.ident.name,
ext: Rc::new(macro_rules::compile(&self.session.parse_sess, &def)),
span: def.span,
});
invocation.legacy_scope.set(LegacyScope::Binding(binding));
self.macro_names.insert(def.ident.name);
if export {
def.id = self.next_node_id();
self.exported_macros.push(def);
}
}
fn add_ext(&mut self, ident: ast::Ident, ext: Rc<SyntaxExtension>) {
if let NormalTT(..) = *ext {
self.macro_names.insert(ident.name);
}
2016-10-06 03:04:30 -05:00
self.builtin_macros.insert(ident.name, ext);
}
fn add_expansions_at_stmt(&mut self, id: ast::NodeId, macros: Vec<Mark>) {
self.macros_at_scope.insert(id, macros);
}
fn find_attr_invoc(&mut self, attrs: &mut Vec<ast::Attribute>) -> Option<ast::Attribute> {
for i in 0..attrs.len() {
let name = intern(&attrs[i].name());
2016-10-06 03:04:30 -05:00
match self.builtin_macros.get(&name) {
Some(ext) => match **ext {
2016-09-06 00:57:58 -05:00
MultiModifier(..) | MultiDecorator(..) | SyntaxExtension::AttrProcMacro(..) => {
return Some(attrs.remove(i))
}
_ => {}
},
None => {}
}
}
None
}
fn resolve_macro(&mut self, scope: Mark, path: &ast::Path, force: bool)
-> Result<Rc<SyntaxExtension>, Determinacy> {
if path.segments.len() > 1 || path.global || !path.segments[0].parameters.is_empty() {
self.session.span_err(path.span, "expected macro name without module separators");
return Err(Determinacy::Determined);
}
let name = path.segments[0].identifier.name;
2016-10-07 19:30:24 -05:00
let invocation = self.invocations[&scope];
if let LegacyScope::Expansion(parent) = invocation.legacy_scope.get() {
invocation.legacy_scope.set(LegacyScope::simplify_expansion(parent));
}
2016-10-31 17:17:15 -05:00
self.resolve_macro_name(invocation.legacy_scope.get(), name).ok_or_else(|| {
if force {
let msg = format!("macro undefined: '{}!'", name);
let mut err = self.session.struct_span_err(path.span, &msg);
self.suggest_macro_name(&name.as_str(), &mut err);
err.emit();
Determinacy::Determined
} else {
Determinacy::Undetermined
}
2016-09-25 22:17:05 -05:00
})
}
}
impl<'a> Resolver<'a> {
2016-10-31 17:17:15 -05:00
pub fn resolve_macro_name(&mut self, mut scope: LegacyScope<'a>, name: ast::Name)
-> Option<Rc<SyntaxExtension>> {
2016-10-31 17:17:15 -05:00
let mut possible_time_travel = None;
2016-10-06 03:04:30 -05:00
let mut relative_depth: u32 = 0;
loop {
2016-10-06 03:04:30 -05:00
scope = match scope {
LegacyScope::Empty => break,
LegacyScope::Expansion(invocation) => {
if let LegacyScope::Empty = invocation.expansion.get() {
2016-10-31 17:17:15 -05:00
if possible_time_travel.is_none() {
possible_time_travel = Some(scope);
}
2016-10-06 03:04:30 -05:00
invocation.legacy_scope.get()
} else {
relative_depth += 1;
invocation.expansion.get()
}
2016-10-06 03:04:30 -05:00
}
LegacyScope::Invocation(invocation) => {
2016-10-10 22:48:54 -05:00
relative_depth = relative_depth.saturating_sub(1);
invocation.legacy_scope.get()
}
LegacyScope::Binding(binding) => {
if binding.name == name {
2016-10-31 17:17:15 -05:00
if let Some(scope) = possible_time_travel {
// Check for disallowed shadowing later
self.lexical_macro_resolutions.push((name, scope));
} else if relative_depth > 0 {
self.disallowed_shadowing.push(binding);
2016-10-06 03:04:30 -05:00
}
2016-10-10 22:48:54 -05:00
return Some(binding.ext.clone());
}
2016-10-10 22:48:54 -05:00
binding.parent
}
2016-10-06 03:04:30 -05:00
};
}
2016-10-06 03:04:30 -05:00
2016-10-31 17:17:15 -05:00
if let Some(scope) = possible_time_travel {
self.lexical_macro_resolutions.push((name, scope));
}
2016-10-06 03:04:30 -05:00
self.builtin_macros.get(&name).cloned()
}
fn suggest_macro_name(&mut self, name: &str, err: &mut DiagnosticBuilder<'a>) {
if let Some(suggestion) = find_best_match_for_name(self.macro_names.iter(), name, None) {
if suggestion != name {
err.help(&format!("did you mean `{}!`?", suggestion));
} else {
err.help(&format!("have you added the `#[macro_use]` on the module/import?"));
}
}
}
2016-10-06 03:04:30 -05:00
fn collect_def_ids(&mut self, invocation: &'a InvocationData<'a>, expansion: &Expansion) {
let Resolver { ref mut invocations, arenas, graph_root, .. } = *self;
2016-10-06 03:04:30 -05:00
let InvocationData { def_index, const_integer, .. } = *invocation;
2016-09-16 03:50:34 -05:00
let visit_macro_invoc = &mut |invoc: map::MacroInvocationData| {
invocations.entry(invoc.mark).or_insert_with(|| {
arenas.alloc_invocation_data(InvocationData {
2016-09-16 03:50:34 -05:00
def_index: invoc.def_index,
const_integer: invoc.const_integer,
module: Cell::new(graph_root),
2016-10-06 03:04:30 -05:00
expansion: Cell::new(LegacyScope::Empty),
legacy_scope: Cell::new(LegacyScope::Empty),
2016-09-16 03:50:34 -05:00
})
});
};
2016-09-16 01:45:03 -05:00
let mut def_collector = DefCollector::new(&mut self.definitions);
def_collector.visit_macro_invoc = Some(visit_macro_invoc);
def_collector.with_parent(def_index, |def_collector| {
if const_integer {
if let Expansion::Expr(ref expr) = *expansion {
def_collector.visit_ast_const_integer(expr);
}
}
expansion.visit_with(def_collector)
});
}
}