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Instead of renaming, treat differently marked identifiers as unequal

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This commit is contained in:
Jeffrey Seyfried 2016-06-22 02:50:05 +00:00
parent ca924047de
commit a15dfca54f
6 changed files with 37 additions and 560 deletions
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53
src/librustc_resolve/lib.rs
View file

@ -53,7 +53,6 @@ use rustc::ty::subst::{ParamSpace, FnSpace, TypeSpace};
use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap}; use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
use rustc::util::nodemap::{NodeMap, NodeSet, FnvHashMap, FnvHashSet}; use rustc::util::nodemap::{NodeMap, NodeSet, FnvHashMap, FnvHashSet};
use syntax::ext::mtwt;
use syntax::ast::{self, FloatTy}; use syntax::ast::{self, FloatTy};
use syntax::ast::{CRATE_NODE_ID, Name, NodeId, CrateNum, IntTy, UintTy}; use syntax::ast::{CRATE_NODE_ID, Name, NodeId, CrateNum, IntTy, UintTy};
use syntax::parse::token::{self, keywords}; use syntax::parse::token::{self, keywords};
@ -462,7 +461,7 @@ struct BindingInfo {
} }
// Map from the name in a pattern to its binding mode. // Map from the name in a pattern to its binding mode.
type BindingMap = HashMap<Name, BindingInfo>; type BindingMap = HashMap<ast::Ident, BindingInfo>;
#[derive(Copy, Clone, PartialEq, Eq, Debug)] #[derive(Copy, Clone, PartialEq, Eq, Debug)]
enum PatternSource { enum PatternSource {
@ -668,7 +667,7 @@ enum ModulePrefixResult<'a> {
/// One local scope. /// One local scope.
#[derive(Debug)] #[derive(Debug)]
struct Rib<'a> { struct Rib<'a> {
bindings: HashMap<Name, Def>, bindings: HashMap<ast::Ident, Def>,
kind: RibKind<'a>, kind: RibKind<'a>,
} }
@ -1385,15 +1384,17 @@ impl<'a> Resolver<'a> {
/// Invariant: This must only be called during main resolution, not during /// Invariant: This must only be called during main resolution, not during
/// import resolution. /// import resolution.
fn resolve_ident_in_lexical_scope(&mut self, fn resolve_ident_in_lexical_scope(&mut self,
ident: ast::Ident, mut ident: ast::Ident,
ns: Namespace, ns: Namespace,
record_used: bool) record_used: bool)
-> Option<LexicalScopeBinding<'a>> { -> Option<LexicalScopeBinding<'a>> {
let name = match ns { ValueNS => mtwt::resolve(ident), TypeNS => ident.name }; if ns == TypeNS {
ident = ast::Ident::with_empty_ctxt(ident.name);
}
// Walk backwards up the ribs in scope. // Walk backwards up the ribs in scope.
for i in (0 .. self.get_ribs(ns).len()).rev() { for i in (0 .. self.get_ribs(ns).len()).rev() {
if let Some(def) = self.get_ribs(ns)[i].bindings.get(&name).cloned() { if let Some(def) = self.get_ribs(ns)[i].bindings.get(&ident).cloned() {
// The ident resolves to a type parameter or local variable. // The ident resolves to a type parameter or local variable.
return Some(LexicalScopeBinding::LocalDef(LocalDef { return Some(LexicalScopeBinding::LocalDef(LocalDef {
ribs: Some((ns, i)), ribs: Some((ns, i)),
@ -1556,7 +1557,7 @@ impl<'a> Resolver<'a> {
/// Searches the current set of local scopes for labels. /// Searches the current set of local scopes for labels.
/// Stops after meeting a closure. /// Stops after meeting a closure.
fn search_label(&self, name: Name) -> Option<Def> { fn search_label(&self, ident: ast::Ident) -> Option<Def> {
for rib in self.label_ribs.iter().rev() { for rib in self.label_ribs.iter().rev() {
match rib.kind { match rib.kind {
NormalRibKind => { NormalRibKind => {
@ -1567,7 +1568,7 @@ impl<'a> Resolver<'a> {
return None; return None;
} }
} }
let result = rib.bindings.get(&name).cloned(); let result = rib.bindings.get(&ident).cloned();
if result.is_some() { if result.is_some() {
return result; return result;
} }
@ -1716,7 +1717,7 @@ impl<'a> Resolver<'a> {
// plain insert (no renaming) // plain insert (no renaming)
let def_id = self.definitions.local_def_id(type_parameter.id); let def_id = self.definitions.local_def_id(type_parameter.id);
let def = Def::TyParam(space, index as u32, def_id, name); let def = Def::TyParam(space, index as u32, def_id, name);
function_type_rib.bindings.insert(name, def); function_type_rib.bindings.insert(ast::Ident::with_empty_ctxt(name), def);
} }
self.type_ribs.push(function_type_rib); self.type_ribs.push(function_type_rib);
} }
@ -1887,7 +1888,7 @@ impl<'a> Resolver<'a> {
let mut self_type_rib = Rib::new(NormalRibKind); let mut self_type_rib = Rib::new(NormalRibKind);
// plain insert (no renaming, types are not currently hygienic....) // plain insert (no renaming, types are not currently hygienic....)
self_type_rib.bindings.insert(keywords::SelfType.name(), self_def); self_type_rib.bindings.insert(keywords::SelfType.ident(), self_def);
self.type_ribs.push(self_type_rib); self.type_ribs.push(self_type_rib);
f(self); f(self);
self.type_ribs.pop(); self.type_ribs.pop();
@ -1998,7 +1999,7 @@ impl<'a> Resolver<'a> {
_ => false, _ => false,
} { } {
let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode }; let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
binding_map.insert(mtwt::resolve(ident.node), binding_info); binding_map.insert(ident.node, binding_info);
} }
} }
true true
@ -2020,15 +2021,14 @@ impl<'a> Resolver<'a> {
for (&key, &binding_0) in &map_0 { for (&key, &binding_0) in &map_0 {
match map_i.get(&key) { match map_i.get(&key) {
None => { None => {
resolve_error(self, let error = ResolutionError::VariableNotBoundInPattern(key.name, 1, i + 1);
p.span, resolve_error(self, p.span, error);
ResolutionError::VariableNotBoundInPattern(key, 1, i + 1));
} }
Some(binding_i) => { Some(binding_i) => {
if binding_0.binding_mode != binding_i.binding_mode { if binding_0.binding_mode != binding_i.binding_mode {
resolve_error(self, resolve_error(self,
binding_i.span, binding_i.span,
ResolutionError::VariableBoundWithDifferentMode(key, ResolutionError::VariableBoundWithDifferentMode(key.name,
i + 1)); i + 1));
} }
} }
@ -2039,7 +2039,7 @@ impl<'a> Resolver<'a> {
if !map_0.contains_key(&key) { if !map_0.contains_key(&key) {
resolve_error(self, resolve_error(self,
binding.span, binding.span,
ResolutionError::VariableNotBoundInPattern(key, i + 1, 1)); ResolutionError::VariableNotBoundInPattern(key.name, i + 1, 1));
} }
} }
} }
@ -2173,16 +2173,15 @@ impl<'a> Resolver<'a> {
pat_id: NodeId, pat_id: NodeId,
outer_pat_id: NodeId, outer_pat_id: NodeId,
pat_src: PatternSource, pat_src: PatternSource,
bindings: &mut HashMap<Name, NodeId>) bindings: &mut HashMap<ast::Ident, NodeId>)
-> PathResolution { -> PathResolution {
// Add the binding to the local ribs, if it // Add the binding to the local ribs, if it
// doesn't already exist in the bindings map. (We // doesn't already exist in the bindings map. (We
// must not add it if it's in the bindings map // must not add it if it's in the bindings map
// because that breaks the assumptions later // because that breaks the assumptions later
// passes make about or-patterns.) // passes make about or-patterns.)
let renamed = mtwt::resolve(ident.node);
let mut def = Def::Local(self.definitions.local_def_id(pat_id), pat_id); let mut def = Def::Local(self.definitions.local_def_id(pat_id), pat_id);
match bindings.get(&renamed).cloned() { match bindings.get(&ident.node).cloned() {
Some(id) if id == outer_pat_id => { Some(id) if id == outer_pat_id => {
// `Variant(a, a)`, error // `Variant(a, a)`, error
resolve_error( resolve_error(
@ -2204,7 +2203,7 @@ impl<'a> Resolver<'a> {
Some(..) if pat_src == PatternSource::Match => { Some(..) if pat_src == PatternSource::Match => {
// `Variant1(a) | Variant2(a)`, ok // `Variant1(a) | Variant2(a)`, ok
// Reuse definition from the first `a`. // Reuse definition from the first `a`.
def = self.value_ribs.last_mut().unwrap().bindings[&renamed]; def = self.value_ribs.last_mut().unwrap().bindings[&ident.node];
} }
Some(..) => { Some(..) => {
span_bug!(ident.span, "two bindings with the same name from \ span_bug!(ident.span, "two bindings with the same name from \
@ -2213,8 +2212,8 @@ impl<'a> Resolver<'a> {
None => { None => {
// A completely fresh binding, add to the lists if it's valid. // A completely fresh binding, add to the lists if it's valid.
if ident.node.name != keywords::Invalid.name() { if ident.node.name != keywords::Invalid.name() {
bindings.insert(renamed, outer_pat_id); bindings.insert(ident.node, outer_pat_id);
self.value_ribs.last_mut().unwrap().bindings.insert(renamed, def); self.value_ribs.last_mut().unwrap().bindings.insert(ident.node, def);
} }
} }
} }
@ -2275,7 +2274,7 @@ impl<'a> Resolver<'a> {
pat_src: PatternSource, pat_src: PatternSource,
// Maps idents to the node ID for the // Maps idents to the node ID for the
// outermost pattern that binds them. // outermost pattern that binds them.
bindings: &mut HashMap<Name, NodeId>) { bindings: &mut HashMap<ast::Ident, NodeId>) {
// Visit all direct subpatterns of this pattern. // Visit all direct subpatterns of this pattern.
let outer_pat_id = pat.id; let outer_pat_id = pat.id;
pat.walk(&mut |pat| { pat.walk(&mut |pat| {
@ -2748,7 +2747,7 @@ impl<'a> Resolver<'a> {
let names = self.value_ribs let names = self.value_ribs
.iter() .iter()
.rev() .rev()
.flat_map(|rib| rib.bindings.keys()); .flat_map(|rib| rib.bindings.keys().map(|ident| &ident.name));
if let Some(found) = find_best_match_for_name(names, name, None) { if let Some(found) = find_best_match_for_name(names, name, None) {
if name != found { if name != found {
@ -2759,7 +2758,7 @@ impl<'a> Resolver<'a> {
fn resolve_labeled_block(&mut self, label: Option<ast::Ident>, id: NodeId, block: &Block) { fn resolve_labeled_block(&mut self, label: Option<ast::Ident>, id: NodeId, block: &Block) {
if let Some(label) = label { if let Some(label) = label {
let (label, def) = (mtwt::resolve(label), Def::Label(id)); let def = Def::Label(id);
self.with_label_rib(|this| { self.with_label_rib(|this| {
this.label_ribs.last_mut().unwrap().bindings.insert(label, def); this.label_ribs.last_mut().unwrap().bindings.insert(label, def);
this.visit_block(block); this.visit_block(block);
@ -2966,7 +2965,7 @@ impl<'a> Resolver<'a> {
{ {
let rib = this.label_ribs.last_mut().unwrap(); let rib = this.label_ribs.last_mut().unwrap();
rib.bindings.insert(mtwt::resolve(label.node), def); rib.bindings.insert(label.node, def);
} }
visit::walk_expr(this, expr); visit::walk_expr(this, expr);
@ -2974,7 +2973,7 @@ impl<'a> Resolver<'a> {
} }
ExprKind::Break(Some(label)) | ExprKind::Continue(Some(label)) => { ExprKind::Break(Some(label)) | ExprKind::Continue(Some(label)) => {
match self.search_label(mtwt::resolve(label.node)) { match self.search_label(label.node) {
None => { None => {
self.record_def(expr.id, err_path_resolution()); self.record_def(expr.id, err_path_resolution());
resolve_error(self, resolve_error(self,

37
src/libsyntax/ast.rs
View file

@ -26,7 +26,6 @@ use tokenstream::{TokenTree};
use std::fmt; use std::fmt;
use std::rc::Rc; use std::rc::Rc;
use std::hash::{Hash, Hasher};
use serialize::{Encodable, Decodable, Encoder, Decoder}; use serialize::{Encodable, Decodable, Encoder, Decoder};
/// A name is a part of an identifier, representing a string or gensym. It's /// A name is a part of an identifier, representing a string or gensym. It's
@ -46,7 +45,7 @@ pub struct SyntaxContext(pub u32);
/// An identifier contains a Name (index into the interner /// An identifier contains a Name (index into the interner
/// table) and a SyntaxContext to track renaming and /// table) and a SyntaxContext to track renaming and
/// macro expansion per Flatt et al., "Macros That Work Together" /// macro expansion per Flatt et al., "Macros That Work Together"
#[derive(Clone, Copy, Eq)] #[derive(Clone, Copy, PartialEq, Eq, Hash)]
pub struct Ident { pub struct Ident {
pub name: Name, pub name: Name,
pub ctxt: SyntaxContext pub ctxt: SyntaxContext
@ -93,40 +92,6 @@ impl Ident {
} }
} }
impl PartialEq for Ident {
fn eq(&self, other: &Ident) -> bool {
if self.ctxt != other.ctxt {
// There's no one true way to compare Idents. They can be compared
// non-hygienically `id1.name == id2.name`, hygienically
// `mtwt::resolve(id1) == mtwt::resolve(id2)`, or even member-wise
// `(id1.name, id1.ctxt) == (id2.name, id2.ctxt)` depending on the situation.
// Ideally, PartialEq should not be implemented for Ident at all, but that
// would be too impractical, because many larger structures (Token, in particular)
// including Idents as their parts derive PartialEq and use it for non-hygienic
// comparisons. That's why PartialEq is implemented and defaults to non-hygienic
// comparison. Hash is implemented too and is consistent with PartialEq, i.e. only
// the name of Ident is hashed. Still try to avoid comparing idents in your code
// (especially as keys in hash maps), use one of the three methods listed above
// explicitly.
//
// If you see this panic, then some idents from different contexts were compared
// non-hygienically. It's likely a bug. Use one of the three comparison methods
// listed above explicitly.
panic!("idents with different contexts are compared with operator `==`: \
{:?}, {:?}.", self, other);
}
self.name == other.name
}
}
impl Hash for Ident {
fn hash<H: Hasher>(&self, state: &mut H) {
self.name.hash(state)
}
}
impl fmt::Debug for Ident { impl fmt::Debug for Ident {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}#{}", self.name, self.ctxt.0) write!(f, "{}#{}", self.name, self.ctxt.0)

4
src/libsyntax/ext/base.rs
View file

@ -26,7 +26,6 @@ use parse::token::{InternedString, intern, str_to_ident};
use ptr::P; use ptr::P;
use util::small_vector::SmallVector; use util::small_vector::SmallVector;
use util::lev_distance::find_best_match_for_name; use util::lev_distance::find_best_match_for_name;
use ext::mtwt;
use fold::Folder; use fold::Folder;
use std::collections::{HashMap, HashSet}; use std::collections::{HashMap, HashSet};
@ -483,15 +482,12 @@ pub type NamedSyntaxExtension = (Name, SyntaxExtension);
pub struct BlockInfo { pub struct BlockInfo {
/// Should macros escape from this scope? /// Should macros escape from this scope?
pub macros_escape: bool, pub macros_escape: bool,
/// What are the pending renames?
pub pending_renames: mtwt::RenameList,
} }
impl BlockInfo { impl BlockInfo {
pub fn new() -> BlockInfo { pub fn new() -> BlockInfo {
BlockInfo { BlockInfo {
macros_escape: false, macros_escape: false,
pending_renames: Vec::new(),
} }
} }
} }

428
src/libsyntax/ext/expand.rs
View file

@ -8,8 +8,7 @@
// option. This file may not be copied, modified, or distributed // option. This file may not be copied, modified, or distributed
// except according to those terms. // except according to those terms.
use ast::{Block, Crate, PatKind}; use ast::{Block, Crate, Ident, Mac_, Name, PatKind};
use ast::{Local, Ident, Mac_, Name, SpannedIdent};
use ast::{MacStmtStyle, Mrk, Stmt, StmtKind, ItemKind}; use ast::{MacStmtStyle, Mrk, Stmt, StmtKind, ItemKind};
use ast; use ast;
use attr::HasAttrs; use attr::HasAttrs;
@ -23,8 +22,7 @@ use ext::base::*;
use feature_gate::{self, Features}; use feature_gate::{self, Features};
use fold; use fold;
use fold::*; use fold::*;
use util::move_map::MoveMap; use parse::token::{fresh_mark, intern, keywords};
use parse::token::{fresh_mark, fresh_name, intern, keywords};
use ptr::P; use ptr::P;
use tokenstream::TokenTree; use tokenstream::TokenTree;
use util::small_vector::SmallVector; use util::small_vector::SmallVector;
@ -96,89 +94,15 @@ impl MacroGenerable for Option<P<ast::Expr>> {
} }
} }
pub fn expand_expr(mut expr: ast::Expr, fld: &mut MacroExpander) -> P<ast::Expr> { pub fn expand_expr(expr: ast::Expr, fld: &mut MacroExpander) -> P<ast::Expr> {
match expr.node { match expr.node {
// expr_mac should really be expr_ext or something; it's the // expr_mac should really be expr_ext or something; it's the
// entry-point for all syntax extensions. // entry-point for all syntax extensions.
ast::ExprKind::Mac(mac) => { ast::ExprKind::Mac(mac) => {
return expand_mac_invoc(mac, None, expr.attrs.into(), expr.span, fld); return expand_mac_invoc(mac, None, expr.attrs.into(), expr.span, fld);
} }
_ => P(noop_fold_expr(expr, fld)),
ast::ExprKind::While(cond, body, opt_ident) => {
let cond = fld.fold_expr(cond);
let (body, opt_ident) = expand_loop_block(body, opt_ident, fld);
expr.node = ast::ExprKind::While(cond, body, opt_ident);
} }
ast::ExprKind::WhileLet(pat, cond, body, opt_ident) => {
let pat = fld.fold_pat(pat);
let cond = fld.fold_expr(cond);
// Hygienic renaming of the body.
let ((body, opt_ident), mut rewritten_pats) =
rename_in_scope(vec![pat],
fld,
(body, opt_ident),
|rename_fld, fld, (body, opt_ident)| {
expand_loop_block(rename_fld.fold_block(body), opt_ident, fld)
});
assert!(rewritten_pats.len() == 1);
expr.node = ast::ExprKind::WhileLet(rewritten_pats.remove(0), cond, body, opt_ident);
}
ast::ExprKind::Loop(loop_block, opt_ident) => {
let (loop_block, opt_ident) = expand_loop_block(loop_block, opt_ident, fld);
expr.node = ast::ExprKind::Loop(loop_block, opt_ident);
}
ast::ExprKind::ForLoop(pat, head, body, opt_ident) => {
let pat = fld.fold_pat(pat);
// Hygienic renaming of the for loop body (for loop binds its pattern).
let ((body, opt_ident), mut rewritten_pats) =
rename_in_scope(vec![pat],
fld,
(body, opt_ident),
|rename_fld, fld, (body, opt_ident)| {
expand_loop_block(rename_fld.fold_block(body), opt_ident, fld)
});
assert!(rewritten_pats.len() == 1);
let head = fld.fold_expr(head);
expr.node = ast::ExprKind::ForLoop(rewritten_pats.remove(0), head, body, opt_ident);
}
ast::ExprKind::IfLet(pat, sub_expr, body, else_opt) => {
let pat = fld.fold_pat(pat);
// Hygienic renaming of the body.
let (body, mut rewritten_pats) =
rename_in_scope(vec![pat],
fld,
body,
|rename_fld, fld, body| {
fld.fold_block(rename_fld.fold_block(body))
});
assert!(rewritten_pats.len() == 1);
let else_opt = else_opt.map(|else_opt| fld.fold_expr(else_opt));
let sub_expr = fld.fold_expr(sub_expr);
expr.node = ast::ExprKind::IfLet(rewritten_pats.remove(0), sub_expr, body, else_opt);
}
ast::ExprKind::Closure(capture_clause, fn_decl, block, fn_decl_span) => {
let (rewritten_fn_decl, rewritten_block)
= expand_and_rename_fn_decl_and_block(fn_decl, block, fld);
expr.node = ast::ExprKind::Closure(capture_clause,
rewritten_fn_decl,
rewritten_block,
fn_decl_span);
}
_ => expr = noop_fold_expr(expr, fld),
};
P(expr)
} }
/// Expand a macro invocation. Returns the result of expansion. /// Expand a macro invocation. Returns the result of expansion.
@ -327,41 +251,6 @@ fn expand_mac_invoc<T>(mac: ast::Mac, ident: Option<Ident>, attrs: Vec<ast::Attr
fully_expanded fully_expanded
} }
/// Rename loop label and expand its loop body
///
/// The renaming procedure for loop is different in the sense that the loop
/// body is in a block enclosed by loop head so the renaming of loop label
/// must be propagated to the enclosed context.
fn expand_loop_block(loop_block: P<Block>,
opt_ident: Option<SpannedIdent>,
fld: &mut MacroExpander) -> (P<Block>, Option<SpannedIdent>) {
match opt_ident {
Some(label) => {
let new_label = fresh_name(label.node);
let rename = (label.node, new_label);
// The rename *must not* be added to the pending list of current
// syntax context otherwise an unrelated `break` or `continue` in
// the same context will pick that up in the deferred renaming pass
// and be renamed incorrectly.
let mut rename_list = vec!(rename);
let mut rename_fld = IdentRenamer{renames: &mut rename_list};
let renamed_ident = rename_fld.fold_ident(label.node);
// The rename *must* be added to the enclosed syntax context for
// `break` or `continue` to pick up because by definition they are
// in a block enclosed by loop head.
fld.cx.syntax_env.push_frame();
fld.cx.syntax_env.info().pending_renames.push(rename);
let expanded_block = expand_block_elts(loop_block, fld);
fld.cx.syntax_env.pop_frame();
(expanded_block, Some(Spanned { node: renamed_ident, span: label.span }))
}
None => (fld.fold_block(loop_block), opt_ident)
}
}
// eval $e with a new exts frame. // eval $e with a new exts frame.
// must be a macro so that $e isn't evaluated too early. // must be a macro so that $e isn't evaluated too early.
macro_rules! with_exts_frame { macro_rules! with_exts_frame {
@ -381,20 +270,6 @@ pub fn expand_item(it: P<ast::Item>, fld: &mut MacroExpander)
.into_iter().map(|i| i.expect_item()).collect() .into_iter().map(|i| i.expect_item()).collect()
} }
/// Expand item_kind
fn expand_item_kind(item: ast::ItemKind, fld: &mut MacroExpander) -> ast::ItemKind {
match item {
ast::ItemKind::Fn(decl, unsafety, constness, abi, generics, body) => {
let (rewritten_fn_decl, rewritten_body)
= expand_and_rename_fn_decl_and_block(decl, body, fld);
let expanded_generics = fold::noop_fold_generics(generics,fld);
ast::ItemKind::Fn(rewritten_fn_decl, unsafety, constness, abi,
expanded_generics, rewritten_body)
}
_ => noop_fold_item_kind(item, fld)
}
}
// does this attribute list contain "macro_use" ? // does this attribute list contain "macro_use" ?
fn contains_macro_use(fld: &mut MacroExpander, attrs: &[ast::Attribute]) -> bool { fn contains_macro_use(fld: &mut MacroExpander, attrs: &[ast::Attribute]) -> bool {
for attr in attrs { for attr in attrs {
@ -425,16 +300,9 @@ fn contains_macro_use(fld: &mut MacroExpander, attrs: &[ast::Attribute]) -> bool
/// Expand a stmt /// Expand a stmt
fn expand_stmt(stmt: Stmt, fld: &mut MacroExpander) -> SmallVector<Stmt> { fn expand_stmt(stmt: Stmt, fld: &mut MacroExpander) -> SmallVector<Stmt> {
// perform all pending renames
let stmt = {
let pending_renames = &mut fld.cx.syntax_env.info().pending_renames;
let mut rename_fld = IdentRenamer{renames:pending_renames};
rename_fld.fold_stmt(stmt).expect_one("rename_fold didn't return one value")
};
let (mac, style, attrs) = match stmt.node { let (mac, style, attrs) = match stmt.node {
StmtKind::Mac(mac) => mac.unwrap(), StmtKind::Mac(mac) => mac.unwrap(),
_ => return expand_non_macro_stmt(stmt, fld) _ => return noop_fold_stmt(stmt, fld)
}; };
let mut fully_expanded: SmallVector<ast::Stmt> = let mut fully_expanded: SmallVector<ast::Stmt> =
@ -458,167 +326,6 @@ fn expand_stmt(stmt: Stmt, fld: &mut MacroExpander) -> SmallVector<Stmt> {
fully_expanded fully_expanded
} }
// expand a non-macro stmt. this is essentially the fallthrough for
// expand_stmt, above.
fn expand_non_macro_stmt(stmt: Stmt, fld: &mut MacroExpander)
-> SmallVector<Stmt> {
// is it a let?
match stmt.node {
StmtKind::Local(local) => {
// take it apart:
let rewritten_local = local.map(|Local {id, pat, ty, init, span, attrs}| {
// expand the ty since TyKind::FixedLengthVec contains an Expr
// and thus may have a macro use
let expanded_ty = ty.map(|t| fld.fold_ty(t));
// expand the pat (it might contain macro uses):
let expanded_pat = fld.fold_pat(pat);
// find the PatIdents in the pattern:
// oh dear heaven... this is going to include the enum
// names, as well... but that should be okay, as long as
// the new names are gensyms for the old ones.
// generate fresh names, push them to a new pending list
let idents = pattern_bindings(&expanded_pat);
let mut new_pending_renames =
idents.iter().map(|ident| (*ident, fresh_name(*ident))).collect();
// rewrite the pattern using the new names (the old
// ones have already been applied):
let rewritten_pat = {
// nested binding to allow borrow to expire:
let mut rename_fld = IdentRenamer{renames: &mut new_pending_renames};
rename_fld.fold_pat(expanded_pat)
};
// add them to the existing pending renames:
fld.cx.syntax_env.info().pending_renames
.extend(new_pending_renames);
Local {
id: id,
ty: expanded_ty,
pat: rewritten_pat,
// also, don't forget to expand the init:
init: init.map(|e| fld.fold_expr(e)),
span: span,
attrs: fold::fold_thin_attrs(attrs, fld),
}
});
SmallVector::one(Stmt {
id: stmt.id,
node: StmtKind::Local(rewritten_local),
span: stmt.span,
})
}
_ => noop_fold_stmt(stmt, fld),
}
}
// expand the arm of a 'match', renaming for macro hygiene
fn expand_arm(arm: ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
// expand pats... they might contain macro uses:
let expanded_pats = arm.pats.move_map(|pat| fld.fold_pat(pat));
if expanded_pats.is_empty() {
panic!("encountered match arm with 0 patterns");
}
// apply renaming and then expansion to the guard and the body:
let ((rewritten_guard, rewritten_body), rewritten_pats) =
rename_in_scope(expanded_pats,
fld,
(arm.guard, arm.body),
|rename_fld, fld, (ag, ab)|{
let rewritten_guard = ag.map(|g| fld.fold_expr(rename_fld.fold_expr(g)));
let rewritten_body = fld.fold_expr(rename_fld.fold_expr(ab));
(rewritten_guard, rewritten_body)
});
ast::Arm {
attrs: fold::fold_attrs(arm.attrs, fld),
pats: rewritten_pats,
guard: rewritten_guard,
body: rewritten_body,
}
}
fn rename_in_scope<X, F>(pats: Vec<P<ast::Pat>>,
fld: &mut MacroExpander,
x: X,
f: F)
-> (X, Vec<P<ast::Pat>>)
where F: Fn(&mut IdentRenamer, &mut MacroExpander, X) -> X
{
// all of the pats must have the same set of bindings, so use the
// first one to extract them and generate new names:
let idents = pattern_bindings(&pats[0]);
let new_renames = idents.into_iter().map(|id| (id, fresh_name(id))).collect();
// apply the renaming, but only to the PatIdents:
let mut rename_pats_fld = PatIdentRenamer{renames:&new_renames};
let rewritten_pats = pats.move_map(|pat| rename_pats_fld.fold_pat(pat));
let mut rename_fld = IdentRenamer{ renames:&new_renames };
(f(&mut rename_fld, fld, x), rewritten_pats)
}
/// A visitor that extracts the PatKind::Ident (binding) paths
/// from a given thingy and puts them in a mutable
/// array
#[derive(Clone)]
struct PatIdentFinder {
ident_accumulator: Vec<ast::Ident>
}
impl Visitor for PatIdentFinder {
fn visit_pat(&mut self, pattern: &ast::Pat) {
match *pattern {
ast::Pat { id: _, node: PatKind::Ident(_, ref path1, ref inner), span: _ } => {
self.ident_accumulator.push(path1.node);
// visit optional subpattern of PatKind::Ident:
if let Some(ref subpat) = *inner {
self.visit_pat(subpat)
}
}
// use the default traversal for non-PatIdents
_ => visit::walk_pat(self, pattern)
}
}
}
/// find the PatKind::Ident paths in a pattern
fn pattern_bindings(pat: &ast::Pat) -> Vec<ast::Ident> {
let mut name_finder = PatIdentFinder{ident_accumulator:Vec::new()};
name_finder.visit_pat(pat);
name_finder.ident_accumulator
}
/// find the PatKind::Ident paths in a
fn fn_decl_arg_bindings(fn_decl: &ast::FnDecl) -> Vec<ast::Ident> {
let mut pat_idents = PatIdentFinder{ident_accumulator:Vec::new()};
for arg in &fn_decl.inputs {
pat_idents.visit_pat(&arg.pat);
}
pat_idents.ident_accumulator
}
// expand a block. pushes a new exts_frame, then calls expand_block_elts
pub fn expand_block(blk: P<Block>, fld: &mut MacroExpander) -> P<Block> {
// see note below about treatment of exts table
with_exts_frame!(fld.cx.syntax_env,false,
expand_block_elts(blk, fld))
}
// expand the elements of a block.
pub fn expand_block_elts(b: P<Block>, fld: &mut MacroExpander) -> P<Block> {
b.map(|Block {id, stmts, rules, span}| {
let new_stmts = stmts.into_iter().flat_map(|x| {
// perform pending renames and expand macros in the statement
fld.fold_stmt(x).into_iter()
}).collect();
Block {
id: fld.new_id(id),
stmts: new_stmts,
rules: rules,
span: span
}
})
}
fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> { fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> {
match p.node { match p.node {
PatKind::Mac(_) => {} PatKind::Mac(_) => {}
@ -632,58 +339,6 @@ fn expand_pat(p: P<ast::Pat>, fld: &mut MacroExpander) -> P<ast::Pat> {
}) })
} }
/// A tree-folder that applies every rename in its (mutable) list
/// to every identifier, including both bindings and varrefs
/// (and lots of things that will turn out to be neither)
pub struct IdentRenamer<'a> {
renames: &'a mtwt::RenameList,
}
impl<'a> Folder for IdentRenamer<'a> {
fn fold_ident(&mut self, id: Ident) -> Ident {
mtwt::apply_renames(self.renames, id)
}
fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
fold::noop_fold_mac(mac, self)
}
}
/// A tree-folder that applies every rename in its list to
/// the idents that are in PatKind::Ident patterns. This is more narrowly
/// focused than IdentRenamer, and is needed for FnDecl,
/// where we want to rename the args but not the fn name or the generics etc.
pub struct PatIdentRenamer<'a> {
renames: &'a mtwt::RenameList,
}
impl<'a> Folder for PatIdentRenamer<'a> {
fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
match pat.node {
PatKind::Ident(..) => {},
_ => return noop_fold_pat(pat, self)
}
pat.map(|ast::Pat {id, node, span}| match node {
PatKind::Ident(binding_mode, Spanned{span: sp, node: ident}, sub) => {
let new_ident = mtwt::apply_renames(self.renames, ident);
let new_node =
PatKind::Ident(binding_mode,
Spanned{span: sp, node: new_ident},
sub.map(|p| self.fold_pat(p)));
ast::Pat {
id: id,
node: new_node,
span: span,
}
},
_ => unreachable!()
})
}
fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
fold::noop_fold_mac(mac, self)
}
}
fn expand_multi_modified(a: Annotatable, fld: &mut MacroExpander) -> SmallVector<Annotatable> { fn expand_multi_modified(a: Annotatable, fld: &mut MacroExpander) -> SmallVector<Annotatable> {
match a { match a {
Annotatable::Item(it) => match it.node { Annotatable::Item(it) => match it.node {
@ -781,21 +436,6 @@ fn expand_annotatable(mut item: Annotatable, fld: &mut MacroExpander) -> SmallVe
fn expand_impl_item(ii: ast::ImplItem, fld: &mut MacroExpander) fn expand_impl_item(ii: ast::ImplItem, fld: &mut MacroExpander)
-> SmallVector<ast::ImplItem> { -> SmallVector<ast::ImplItem> {
match ii.node { match ii.node {
ast::ImplItemKind::Method(..) => SmallVector::one(ast::ImplItem {
id: ii.id,
ident: ii.ident,
attrs: ii.attrs,
vis: ii.vis,
defaultness: ii.defaultness,
node: match ii.node {
ast::ImplItemKind::Method(sig, body) => {
let (sig, body) = expand_and_rename_method(sig, body, fld);
ast::ImplItemKind::Method(sig, body)
}
_ => unreachable!()
},
span: ii.span,
}),
ast::ImplItemKind::Macro(mac) => { ast::ImplItemKind::Macro(mac) => {
expand_mac_invoc(mac, None, ii.attrs, ii.span, fld) expand_mac_invoc(mac, None, ii.attrs, ii.span, fld)
} }
@ -806,21 +446,6 @@ fn expand_impl_item(ii: ast::ImplItem, fld: &mut MacroExpander)
fn expand_trait_item(ti: ast::TraitItem, fld: &mut MacroExpander) fn expand_trait_item(ti: ast::TraitItem, fld: &mut MacroExpander)
-> SmallVector<ast::TraitItem> { -> SmallVector<ast::TraitItem> {
match ti.node { match ti.node {
ast::TraitItemKind::Method(_, Some(_)) => {
SmallVector::one(ast::TraitItem {
id: ti.id,
ident: ti.ident,
attrs: ti.attrs,
node: match ti.node {
ast::TraitItemKind::Method(sig, Some(body)) => {
let (sig, body) = expand_and_rename_method(sig, body, fld);
ast::TraitItemKind::Method(sig, Some(body))
}
_ => unreachable!()
},
span: ti.span,
})
}
ast::TraitItemKind::Macro(mac) => { ast::TraitItemKind::Macro(mac) => {
expand_mac_invoc(mac, None, ti.attrs, ti.span, fld) expand_mac_invoc(mac, None, ti.attrs, ti.span, fld)
} }
@ -828,39 +453,6 @@ fn expand_trait_item(ti: ast::TraitItem, fld: &mut MacroExpander)
} }
} }
/// Given a fn_decl and a block and a MacroExpander, expand the fn_decl, then use the
/// PatIdents in its arguments to perform renaming in the FnDecl and
/// the block, returning both the new FnDecl and the new Block.
fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Block>,
fld: &mut MacroExpander)
-> (P<ast::FnDecl>, P<ast::Block>) {
let expanded_decl = fld.fold_fn_decl(fn_decl);
let idents = fn_decl_arg_bindings(&expanded_decl);
let renames =
idents.iter().map(|id| (*id,fresh_name(*id))).collect();
// first, a renamer for the PatIdents, for the fn_decl:
let mut rename_pat_fld = PatIdentRenamer{renames: &renames};
let rewritten_fn_decl = rename_pat_fld.fold_fn_decl(expanded_decl);
// now, a renamer for *all* idents, for the body:
let mut rename_fld = IdentRenamer{renames: &renames};
let rewritten_body = fld.fold_block(rename_fld.fold_block(block));
(rewritten_fn_decl,rewritten_body)
}
fn expand_and_rename_method(sig: ast::MethodSig, body: P<ast::Block>,
fld: &mut MacroExpander)
-> (ast::MethodSig, P<ast::Block>) {
let (rewritten_fn_decl, rewritten_body)
= expand_and_rename_fn_decl_and_block(sig.decl, body, fld);
(ast::MethodSig {
generics: fld.fold_generics(sig.generics),
abi: sig.abi,
unsafety: sig.unsafety,
constness: sig.constness,
decl: rewritten_fn_decl
}, rewritten_body)
}
pub fn expand_type(t: P<ast::Ty>, fld: &mut MacroExpander) -> P<ast::Ty> { pub fn expand_type(t: P<ast::Ty>, fld: &mut MacroExpander) -> P<ast::Ty> {
let t = match t.node.clone() { let t = match t.node.clone() {
ast::TyKind::Mac(mac) => { ast::TyKind::Mac(mac) => {
@ -983,25 +575,17 @@ impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
result result
} }
fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
expand_item_kind(item, self)
}
fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> { fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
expand_stmt(stmt, self) expand_stmt(stmt, self)
} }
fn fold_block(&mut self, block: P<Block>) -> P<Block> { fn fold_block(&mut self, block: P<Block>) -> P<Block> {
let was_in_block = ::std::mem::replace(&mut self.cx.in_block, true); let was_in_block = ::std::mem::replace(&mut self.cx.in_block, true);
let result = expand_block(block, self); let result = with_exts_frame!(self.cx.syntax_env, false, noop_fold_block(block, self));
self.cx.in_block = was_in_block; self.cx.in_block = was_in_block;
result result
} }
fn fold_arm(&mut self, arm: ast::Arm) -> ast::Arm {
expand_arm(arm, self)
}
fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVector<ast::TraitItem> { fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVector<ast::TraitItem> {
expand_annotatable(Annotatable::TraitItem(P(i)), self) expand_annotatable(Annotatable::TraitItem(P(i)), self)
.into_iter().map(|i| i.expect_trait_item()).collect() .into_iter().map(|i| i.expect_trait_item()).collect()

61
src/libsyntax/ext/mtwt.rs
View file

@ -17,7 +17,7 @@
pub use self::SyntaxContext_::*; pub use self::SyntaxContext_::*;
use ast::{Ident, Mrk, Name, SyntaxContext}; use ast::{Mrk, SyntaxContext};
use std::cell::RefCell; use std::cell::RefCell;
use std::collections::HashMap; use std::collections::HashMap;
@ -25,27 +25,19 @@ use std::collections::HashMap;
/// The SCTable contains a table of SyntaxContext_'s. It /// The SCTable contains a table of SyntaxContext_'s. It
/// represents a flattened tree structure, to avoid having /// represents a flattened tree structure, to avoid having
/// managed pointers everywhere (that caused an ICE). /// managed pointers everywhere (that caused an ICE).
/// the `marks` and `renames` fields are side-tables /// The `marks` ensures that adding the same mark to the
/// that ensure that adding the same mark to the same context /// same context gives you back the same context as before.
/// gives you back the same context as before. This should cut
/// down on memory use *a lot*; applying a mark to a tree containing
/// 50 identifiers would otherwise generate 50 new contexts.
pub struct SCTable { pub struct SCTable {
table: RefCell<Vec<SyntaxContext_>>, table: RefCell<Vec<SyntaxContext_>>,
marks: RefCell<HashMap<(SyntaxContext,Mrk),SyntaxContext>>, marks: RefCell<HashMap<(SyntaxContext,Mrk),SyntaxContext>>,
renames: RefCell<HashMap<Name,SyntaxContext>>,
} }
#[derive(PartialEq, RustcEncodable, RustcDecodable, Hash, Debug, Copy, Clone)] #[derive(PartialEq, RustcEncodable, RustcDecodable, Hash, Debug, Copy, Clone)]
pub enum SyntaxContext_ { pub enum SyntaxContext_ {
EmptyCtxt, EmptyCtxt,
Mark (Mrk,SyntaxContext), Mark (Mrk,SyntaxContext),
Rename (Name),
} }
/// A list of ident->name renamings
pub type RenameList = Vec<(Ident, Name)>;
/// Extend a syntax context with a given mark /// Extend a syntax context with a given mark
pub fn apply_mark(m: Mrk, ctxt: SyntaxContext) -> SyntaxContext { pub fn apply_mark(m: Mrk, ctxt: SyntaxContext) -> SyntaxContext {
with_sctable(|table| apply_mark_internal(m, ctxt, table)) with_sctable(|table| apply_mark_internal(m, ctxt, table))
@ -63,32 +55,6 @@ fn apply_mark_internal(m: Mrk, ctxt: SyntaxContext, table: &SCTable) -> SyntaxCo
} }
} }
/// Extend a syntax context with a given rename
pub fn apply_rename(from: Ident, to: Name, ident: Ident) -> Ident {
with_sctable(|table| apply_rename_internal(from, to, ident, table))
}
/// Extend a syntax context with a given rename and sctable (explicit memoization)
fn apply_rename_internal(from: Ident, to: Name, ident: Ident, table: &SCTable) -> Ident {
if (ident.name, ident.ctxt) != (from.name, from.ctxt) {
return ident;
}
let ctxt = *table.renames.borrow_mut().entry(to).or_insert_with(|| {
SyntaxContext(idx_push(&mut *table.table.borrow_mut(), Rename(to)))
});
Ident { ctxt: ctxt, ..ident }
}
/// Apply a list of renamings to a context
// if these rename lists get long, it would make sense
// to consider memoizing this fold. This may come up
// when we add hygiene to item names.
pub fn apply_renames(renames: &RenameList, ident: Ident) -> Ident {
renames.iter().fold(ident, |ident, &(from, to)| {
apply_rename(from, to, ident)
})
}
/// Fetch the SCTable from TLS, create one if it doesn't yet exist. /// Fetch the SCTable from TLS, create one if it doesn't yet exist.
pub fn with_sctable<T, F>(op: F) -> T where pub fn with_sctable<T, F>(op: F) -> T where
F: FnOnce(&SCTable) -> T, F: FnOnce(&SCTable) -> T,
@ -102,7 +68,6 @@ fn new_sctable_internal() -> SCTable {
SCTable { SCTable {
table: RefCell::new(vec![EmptyCtxt]), table: RefCell::new(vec![EmptyCtxt]),
marks: RefCell::new(HashMap::new()), marks: RefCell::new(HashMap::new()),
renames: RefCell::new(HashMap::new()),
} }
} }
@ -119,7 +84,6 @@ pub fn clear_tables() {
with_sctable(|table| { with_sctable(|table| {
*table.table.borrow_mut() = Vec::new(); *table.table.borrow_mut() = Vec::new();
*table.marks.borrow_mut() = HashMap::new(); *table.marks.borrow_mut() = HashMap::new();
*table.renames.borrow_mut() = HashMap::new();
}); });
} }
@ -128,7 +92,6 @@ pub fn reset_tables() {
with_sctable(|table| { with_sctable(|table| {
*table.table.borrow_mut() = vec![EmptyCtxt]; *table.table.borrow_mut() = vec![EmptyCtxt];
*table.marks.borrow_mut() = HashMap::new(); *table.marks.borrow_mut() = HashMap::new();
*table.renames.borrow_mut() = HashMap::new();
}); });
} }
@ -138,24 +101,6 @@ fn idx_push<T>(vec: &mut Vec<T>, val: T) -> u32 {
(vec.len() - 1) as u32 (vec.len() - 1) as u32
} }
/// Resolve a syntax object to a name, per MTWT.
pub fn resolve(id: Ident) -> Name {
with_sctable(|sctable| {
resolve_internal(id, sctable)
})
}
/// Resolve a syntax object to a name, per MTWT.
/// adding memoization to resolve 500+ seconds in resolve for librustc (!)
fn resolve_internal(id: Ident, table: &SCTable) -> Name {
match table.table.borrow()[id.ctxt.0 as usize] {
EmptyCtxt => id.name,
// ignore marks here:
Mark(_, subctxt) => resolve_internal(Ident::new(id.name, subctxt), table),
Rename(name) => name,
}
}
/// Return the outer mark for a context with a mark at the outside. /// Return the outer mark for a context with a mark at the outside.
/// FAILS when outside is not a mark. /// FAILS when outside is not a mark.
pub fn outer_mark(ctxt: SyntaxContext) -> Mrk { pub fn outer_mark(ctxt: SyntaxContext) -> Mrk {

12
src/libsyntax/parse/token.rs
View file

@ -15,7 +15,6 @@ pub use self::Lit::*;
pub use self::Token::*; pub use self::Token::*;
use ast::{self, BinOpKind}; use ast::{self, BinOpKind};
use ext::mtwt;
use ptr::P; use ptr::P;
use util::interner::{RcStr, StrInterner}; use util::interner::{RcStr, StrInterner};
use util::interner; use util::interner;
@ -313,17 +312,6 @@ impl Token {
_ => false, _ => false,
} }
} }
/// Hygienic identifier equality comparison.
///
/// See `styntax::ext::mtwt`.
pub fn mtwt_eq(&self, other : &Token) -> bool {
match (self, other) {
(&Ident(id1), &Ident(id2)) | (&Lifetime(id1), &Lifetime(id2)) =>
mtwt::resolve(id1) == mtwt::resolve(id2),
_ => *self == *other
}
}
} }
#[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash)] #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash)]