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rust/src/librustc/middle/resolve.rs

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// Copyright 2012-2014 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.
#![allow(non_camel_case_types)]
use driver::session::Session;
use metadata::csearch;
use metadata::decoder::{DefLike, DlDef, DlField, DlImpl};
use middle::lang_items::LanguageItems;
use middle::lint::{UnnecessaryQualification, UnusedImports};
use middle::pat_util::pat_bindings;
use util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
use syntax::ast::*;
use syntax::ast;
use syntax::ast_util::{def_id_of_def, local_def};
use syntax::ast_util::{path_to_ident, walk_pat, trait_method_to_ty_method};
use syntax::ext::mtwt;
use syntax::parse::token::special_idents;
use syntax::parse::token;
use syntax::print::pprust::path_to_str;
use syntax::codemap::{Span, DUMMY_SP, Pos};
use syntax::owned_slice::OwnedSlice;
use syntax::visit;
use syntax::visit::Visitor;
use collections::{HashMap, HashSet};
use std::cell::{Cell, RefCell};
use std::mem::replace;
use std::rc::{Rc, Weak};
use std::strbuf::StrBuf;
use std::uint;
// Definition mapping
pub type DefMap = RefCell<NodeMap<Def>>;
struct binding_info {
span: Span,
binding_mode: BindingMode,
}
// Map from the name in a pattern to its binding mode.
type BindingMap = HashMap<Name,binding_info>;
// Trait method resolution
pub type TraitMap = NodeMap<Vec<DefId> >;
// This is the replacement export map. It maps a module to all of the exports
// within.
pub type ExportMap2 = RefCell<NodeMap<Vec<Export2> >>;
pub struct Export2 {
pub name: StrBuf, // The name of the target.
pub def_id: DefId, // The definition of the target.
}
// This set contains all exported definitions from external crates. The set does
// not contain any entries from local crates.
pub type ExternalExports = DefIdSet;
// FIXME: dox
pub type LastPrivateMap = NodeMap<LastPrivate>;
pub enum LastPrivate {
LastMod(PrivateDep),
// `use` directives (imports) can refer to two separate definitions in the
// type and value namespaces. We record here the last private node for each
// and whether the import is in fact used for each.
// If the Option<PrivateDep> fields are None, it means there is no definition
// in that namespace.
LastImport{pub value_priv: Option<PrivateDep>,
pub value_used: ImportUse,
pub type_priv: Option<PrivateDep>,
pub type_used: ImportUse},
}
pub enum PrivateDep {
AllPublic,
DependsOn(DefId),
}
// How an import is used.
#[deriving(Eq)]
pub enum ImportUse {
Unused, // The import is not used.
Used, // The import is used.
}
impl LastPrivate {
fn or(self, other: LastPrivate) -> LastPrivate {
match (self, other) {
(me, LastMod(AllPublic)) => me,
(_, other) => other,
}
}
}
#[deriving(Eq)]
enum PatternBindingMode {
RefutableMode,
LocalIrrefutableMode,
ArgumentIrrefutableMode,
}
#[deriving(Eq, TotalEq, Hash)]
enum Namespace {
TypeNS,
ValueNS
}
#[deriving(Eq)]
enum NamespaceError {
NoError,
ModuleError,
TypeError,
ValueError
}
/// A NamespaceResult represents the result of resolving an import in
/// a particular namespace. The result is either definitely-resolved,
/// definitely- unresolved, or unknown.
#[deriving(Clone)]
enum NamespaceResult {
/// Means that resolve hasn't gathered enough information yet to determine
/// whether the name is bound in this namespace. (That is, it hasn't
/// resolved all `use` directives yet.)
UnknownResult,
/// Means that resolve has determined that the name is definitely
/// not bound in the namespace.
UnboundResult,
/// Means that resolve has determined that the name is bound in the Module
/// argument, and specified by the NameBindings argument.
BoundResult(Rc<Module>, Rc<NameBindings>)
}
impl NamespaceResult {
fn is_unknown(&self) -> bool {
match *self {
UnknownResult => true,
_ => false
}
}
fn is_unbound(&self) -> bool {
match *self {
UnboundResult => true,
_ => false
}
}
}
enum NameDefinition {
NoNameDefinition, //< The name was unbound.
ChildNameDefinition(Def, LastPrivate), //< The name identifies an immediate child.
ImportNameDefinition(Def, LastPrivate) //< The name identifies an import.
}
impl<'a> Visitor<()> for Resolver<'a> {
fn visit_item(&mut self, item: &Item, _: ()) {
self.resolve_item(item);
}
fn visit_arm(&mut self, arm: &Arm, _: ()) {
self.resolve_arm(arm);
}
fn visit_block(&mut self, block: &Block, _: ()) {
self.resolve_block(block);
}
fn visit_expr(&mut self, expr: &Expr, _: ()) {
self.resolve_expr(expr);
}
fn visit_local(&mut self, local: &Local, _: ()) {
self.resolve_local(local);
}
fn visit_ty(&mut self, ty: &Ty, _: ()) {
self.resolve_type(ty);
}
}
/// Contains data for specific types of import directives.
enum ImportDirectiveSubclass {
SingleImport(Ident /* target */, Ident /* source */),
GlobImport
}
/// The context that we thread through while building the reduced graph.
#[deriving(Clone)]
enum ReducedGraphParent {
ModuleReducedGraphParent(Rc<Module>)
}
impl ReducedGraphParent {
fn module(&self) -> Rc<Module> {
match *self {
ModuleReducedGraphParent(ref m) => {
m.clone()
}
}
}
}
enum ResolveResult<T> {
Failed, // Failed to resolve the name.
Indeterminate, // Couldn't determine due to unresolved globs.
Success(T) // Successfully resolved the import.
}
impl<T> ResolveResult<T> {
fn indeterminate(&self) -> bool {
match *self { Indeterminate => true, _ => false }
}
}
enum FallbackSuggestion {
NoSuggestion,
Field,
Method,
TraitMethod,
StaticMethod(StrBuf),
StaticTraitMethod(StrBuf),
}
enum TypeParameters<'a> {
NoTypeParameters, //< No type parameters.
HasTypeParameters(&'a Generics, //< Type parameters.
NodeId, //< ID of the enclosing item
// The index to start numbering the type parameters at.
// This is zero if this is the outermost set of type
// parameters, or equal to the number of outer type
// parameters. For example, if we have:
//
// impl I<T> {
// fn method<U>() { ... }
// }
//
// The index at the method site will be 1, because the
// outer T had index 0.
uint,
// The kind of the rib used for type parameters.
RibKind)
}
// The rib kind controls the translation of argument or local definitions
// (`def_arg` or `def_local`) to upvars (`def_upvar`).
enum RibKind {
// No translation needs to be applied.
NormalRibKind,
// We passed through a function scope at the given node ID. Translate
// upvars as appropriate.
FunctionRibKind(NodeId /* func id */, NodeId /* body id */),
// We passed through an impl or trait and are now in one of its
// methods. Allow references to ty params that impl or trait
// binds. Disallow any other upvars (including other ty params that are
// upvars).
// parent; method itself
MethodRibKind(NodeId, MethodSort),
// We passed through a function *item* scope. Disallow upvars.
OpaqueFunctionRibKind,
// We're in a constant item. Can't refer to dynamic stuff.
ConstantItemRibKind
}
// Methods can be required or provided. Required methods only occur in traits.
enum MethodSort {
Required,
Provided(NodeId)
}
enum UseLexicalScopeFlag {
DontUseLexicalScope,
UseLexicalScope
}
enum ModulePrefixResult {
NoPrefixFound,
PrefixFound(Rc<Module>, uint)
}
#[deriving(Eq)]
enum NameSearchType {
/// We're doing a name search in order to resolve a `use` directive.
ImportSearch,
/// We're doing a name search in order to resolve a path type, a path
/// expression, or a path pattern.
PathSearch,
}
enum BareIdentifierPatternResolution {
FoundStructOrEnumVariant(Def, LastPrivate),
FoundConst(Def, LastPrivate),
BareIdentifierPatternUnresolved
}
// Specifies how duplicates should be handled when adding a child item if
// another item exists with the same name in some namespace.
#[deriving(Eq)]
enum DuplicateCheckingMode {
ForbidDuplicateModules,
ForbidDuplicateTypes,
ForbidDuplicateValues,
ForbidDuplicateTypesAndValues,
OverwriteDuplicates
}
/// One local scope.
struct Rib {
bindings: RefCell<HashMap<Name, DefLike>>,
kind: RibKind,
}
impl Rib {
fn new(kind: RibKind) -> Rib {
Rib {
bindings: RefCell::new(HashMap::new()),
kind: kind
}
}
}
/// One import directive.
struct ImportDirective {
module_path: Vec<Ident>,
subclass: ImportDirectiveSubclass,
span: Span,
id: NodeId,
is_public: bool, // see note in ImportResolution about how to use this
}
impl ImportDirective {
fn new(module_path: Vec<Ident> ,
subclass: ImportDirectiveSubclass,
span: Span,
id: NodeId,
is_public: bool)
-> ImportDirective {
ImportDirective {
module_path: module_path,
subclass: subclass,
span: span,
id: id,
is_public: is_public,
}
}
}
/// The item that an import resolves to.
#[deriving(Clone)]
struct Target {
target_module: Rc<Module>,
bindings: Rc<NameBindings>,
}
impl Target {
fn new(target_module: Rc<Module>, bindings: Rc<NameBindings>) -> Target {
Target {
target_module: target_module,
bindings: bindings
}
}
}
/// An ImportResolution represents a particular `use` directive.
struct ImportResolution {
/// Whether this resolution came from a `use` or a `pub use`. Note that this
/// should *not* be used whenever resolution is being performed, this is
/// only looked at for glob imports statements currently. Privacy testing
/// occurs during a later phase of compilation.
is_public: bool,
// The number of outstanding references to this name. When this reaches
// zero, outside modules can count on the targets being correct. Before
// then, all bets are off; future imports could override this name.
outstanding_references: uint,
/// The value that this `use` directive names, if there is one.
value_target: Option<Target>,
/// The source node of the `use` directive leading to the value target
/// being non-none
value_id: NodeId,
/// The type that this `use` directive names, if there is one.
type_target: Option<Target>,
/// The source node of the `use` directive leading to the type target
/// being non-none
type_id: NodeId,
}
impl ImportResolution {
fn new(id: NodeId, is_public: bool) -> ImportResolution {
ImportResolution {
type_id: id,
value_id: id,
outstanding_references: 0,
value_target: None,
type_target: None,
is_public: is_public,
}
}
fn target_for_namespace(&self, namespace: Namespace)
-> Option<Target> {
match namespace {
TypeNS => self.type_target.clone(),
ValueNS => self.value_target.clone(),
}
}
fn id(&self, namespace: Namespace) -> NodeId {
match namespace {
TypeNS => self.type_id,
ValueNS => self.value_id,
}
}
}
/// The link from a module up to its nearest parent node.
#[deriving(Clone)]
enum ParentLink {
NoParentLink,
ModuleParentLink(Weak<Module>, Ident),
BlockParentLink(Weak<Module>, NodeId)
}
/// The type of module this is.
#[deriving(Eq)]
enum ModuleKind {
NormalModuleKind,
ExternModuleKind,
TraitModuleKind,
ImplModuleKind,
AnonymousModuleKind,
}
/// One node in the tree of modules.
struct Module {
parent_link: ParentLink,
def_id: Cell<Option<DefId>>,
kind: Cell<ModuleKind>,
is_public: bool,
children: RefCell<HashMap<Name, Rc<NameBindings>>>,
imports: RefCell<Vec<ImportDirective>>,
// The external module children of this node that were declared with
// `extern crate`.
external_module_children: RefCell<HashMap<Name, Rc<Module>>>,
// The anonymous children of this node. Anonymous children are pseudo-
// modules that are implicitly created around items contained within
// blocks.
//
// For example, if we have this:
//
// fn f() {
// fn g() {
// ...
// }
// }
//
// There will be an anonymous module created around `g` with the ID of the
// entry block for `f`.
anonymous_children: RefCell<NodeMap<Rc<Module>>>,
// The status of resolving each import in this module.
import_resolutions: RefCell<HashMap<Name, ImportResolution>>,
// The number of unresolved globs that this module exports.
glob_count: Cell<uint>,
// The index of the import we're resolving.
resolved_import_count: Cell<uint>,
// Whether this module is populated. If not populated, any attempt to
// access the children must be preceded with a
// `populate_module_if_necessary` call.
populated: Cell<bool>,
}
impl Module {
fn new(parent_link: ParentLink,
def_id: Option<DefId>,
kind: ModuleKind,
external: bool,
is_public: bool)
-> Module {
Module {
parent_link: parent_link,
def_id: Cell::new(def_id),
kind: Cell::new(kind),
is_public: is_public,
children: RefCell::new(HashMap::new()),
imports: RefCell::new(Vec::new()),
external_module_children: RefCell::new(HashMap::new()),
anonymous_children: RefCell::new(NodeMap::new()),
import_resolutions: RefCell::new(HashMap::new()),
glob_count: Cell::new(0),
resolved_import_count: Cell::new(0),
populated: Cell::new(!external),
}
}
fn all_imports_resolved(&self) -> bool {
self.imports.borrow().len() == self.resolved_import_count.get()
}
}
// Records a possibly-private type definition.
#[deriving(Clone)]
struct TypeNsDef {
is_public: bool, // see note in ImportResolution about how to use this
module_def: Option<Rc<Module>>,
type_def: Option<Def>,
type_span: Option<Span>
}
// Records a possibly-private value definition.
#[deriving(Clone)]
struct ValueNsDef {
is_public: bool, // see note in ImportResolution about how to use this
def: Def,
value_span: Option<Span>,
}
// Records the definitions (at most one for each namespace) that a name is
// bound to.
struct NameBindings {
type_def: RefCell<Option<TypeNsDef>>, //< Meaning in type namespace.
value_def: RefCell<Option<ValueNsDef>>, //< Meaning in value namespace.
}
/// Ways in which a trait can be referenced
enum TraitReferenceType {
TraitImplementation, // impl SomeTrait for T { ... }
TraitDerivation, // trait T : SomeTrait { ... }
TraitBoundingTypeParameter, // fn f<T:SomeTrait>() { ... }
}
impl NameBindings {
/// Creates a new module in this set of name bindings.
fn define_module(&self,
parent_link: ParentLink,
def_id: Option<DefId>,
kind: ModuleKind,
external: bool,
is_public: bool,
sp: Span) {
// Merges the module with the existing type def or creates a new one.
let module_ = Rc::new(Module::new(parent_link, def_id, kind, external,
is_public));
let type_def = self.type_def.borrow().clone();
match type_def {
None => {
*self.type_def.borrow_mut() = Some(TypeNsDef {
is_public: is_public,
module_def: Some(module_),
type_def: None,
type_span: Some(sp)
});
}
Some(type_def) => {
*self.type_def.borrow_mut() = Some(TypeNsDef {
is_public: is_public,
module_def: Some(module_),
type_span: Some(sp),
type_def: type_def.type_def
});
}
}
}
/// Sets the kind of the module, creating a new one if necessary.
fn set_module_kind(&self,
parent_link: ParentLink,
def_id: Option<DefId>,
kind: ModuleKind,
external: bool,
is_public: bool,
_sp: Span) {
let type_def = self.type_def.borrow().clone();
match type_def {
None => {
let module = Module::new(parent_link, def_id, kind,
external, is_public);
*self.type_def.borrow_mut() = Some(TypeNsDef {
is_public: is_public,
module_def: Some(Rc::new(module)),
type_def: None,
type_span: None,
});
}
Some(type_def) => {
match type_def.module_def {
None => {
let module = Module::new(parent_link,
def_id,
kind,
external,
is_public);
*self.type_def.borrow_mut() = Some(TypeNsDef {
is_public: is_public,
module_def: Some(Rc::new(module)),
type_def: type_def.type_def,
type_span: None,
});
}
Some(module_def) => module_def.kind.set(kind),
}
}
}
}
/// Records a type definition.
fn define_type(&self, def: Def, sp: Span, is_public: bool) {
// Merges the type with the existing type def or creates a new one.
let type_def = self.type_def.borrow().clone();
match type_def {
None => {
*self.type_def.borrow_mut() = Some(TypeNsDef {
module_def: None,
type_def: Some(def),
type_span: Some(sp),
is_public: is_public,
});
}
Some(type_def) => {
*self.type_def.borrow_mut() = Some(TypeNsDef {
type_def: Some(def),
type_span: Some(sp),
module_def: type_def.module_def,
is_public: is_public,
});
}
}
}
/// Records a value definition.
fn define_value(&self, def: Def, sp: Span, is_public: bool) {
*self.value_def.borrow_mut() = Some(ValueNsDef {
def: def,
value_span: Some(sp),
is_public: is_public,
});
}
/// Returns the module node if applicable.
fn get_module_if_available(&self) -> Option<Rc<Module>> {
match *self.type_def.borrow() {
Some(ref type_def) => type_def.module_def.clone(),
None => None
}
}
/**
* Returns the module node. Fails if this node does not have a module
* definition.
*/
fn get_module(&self) -> Rc<Module> {
match self.get_module_if_available() {
None => {
fail!("get_module called on a node with no module \
definition!")
}
Some(module_def) => module_def
}
}
fn defined_in_namespace(&self, namespace: Namespace) -> bool {
match namespace {
TypeNS => return self.type_def.borrow().is_some(),
ValueNS => return self.value_def.borrow().is_some()
}
}
fn defined_in_public_namespace(&self, namespace: Namespace) -> bool {
match namespace {
TypeNS => match *self.type_def.borrow() {
Some(ref def) => def.is_public, None => false
},
ValueNS => match *self.value_def.borrow() {
Some(ref def) => def.is_public, None => false
}
}
}
fn def_for_namespace(&self, namespace: Namespace) -> Option<Def> {
match namespace {
TypeNS => {
match *self.type_def.borrow() {
None => None,
Some(ref type_def) => {
match type_def.type_def {
Some(type_def) => Some(type_def),
None => {
match type_def.module_def {
Some(ref module) => {
match module.def_id.get() {
Some(did) => Some(DefMod(did)),
None => None,
}
}
None => None,
}
}
}
}
}
}
ValueNS => {
match *self.value_def.borrow() {
None => None,
Some(value_def) => Some(value_def.def)
}
}
}
}
fn span_for_namespace(&self, namespace: Namespace) -> Option<Span> {
if self.defined_in_namespace(namespace) {
match namespace {
TypeNS => {
match *self.type_def.borrow() {
None => None,
Some(ref type_def) => type_def.type_span
}
}
ValueNS => {
match *self.value_def.borrow() {
None => None,
Some(ref value_def) => value_def.value_span
}
}
}
} else {
None
}
}
}
fn NameBindings() -> NameBindings {
NameBindings {
type_def: RefCell::new(None),
value_def: RefCell::new(None),
}
}
/// Interns the names of the primitive types.
struct PrimitiveTypeTable {
primitive_types: HashMap<Name, PrimTy>,
}
impl PrimitiveTypeTable {
fn intern(&mut self, string: &str, primitive_type: PrimTy) {
self.primitive_types.insert(token::intern(string), primitive_type);
}
}
fn PrimitiveTypeTable() -> PrimitiveTypeTable {
let mut table = PrimitiveTypeTable {
primitive_types: HashMap::new()
};
table.intern("bool", TyBool);
table.intern("char", TyChar);
table.intern("f32", TyFloat(TyF32));
table.intern("f64", TyFloat(TyF64));
table.intern("f128", TyFloat(TyF128));
table.intern("int", TyInt(TyI));
table.intern("i8", TyInt(TyI8));
table.intern("i16", TyInt(TyI16));
table.intern("i32", TyInt(TyI32));
table.intern("i64", TyInt(TyI64));
table.intern("str", TyStr);
table.intern("uint", TyUint(TyU));
table.intern("u8", TyUint(TyU8));
table.intern("u16", TyUint(TyU16));
table.intern("u32", TyUint(TyU32));
table.intern("u64", TyUint(TyU64));
return table;
}
fn namespace_error_to_str(ns: NamespaceError) -> &'static str {
match ns {
NoError => "",
ModuleError => "module",
TypeError => "type",
ValueError => "value",
}
}
fn Resolver<'a>(session: &'a Session,
lang_items: &'a LanguageItems,
crate_span: Span) -> Resolver<'a> {
let graph_root = NameBindings();
graph_root.define_module(NoParentLink,
Some(DefId { krate: 0, node: 0 }),
NormalModuleKind,
false,
true,
crate_span);
let current_module = graph_root.get_module();
let this = Resolver {
session: session,
lang_items: lang_items,
// The outermost module has def ID 0; this is not reflected in the
// AST.
graph_root: graph_root,
method_map: RefCell::new(FnvHashMap::new()),
structs: FnvHashMap::new(),
unresolved_imports: 0,
current_module: current_module,
value_ribs: RefCell::new(Vec::new()),
type_ribs: RefCell::new(Vec::new()),
label_ribs: RefCell::new(Vec::new()),
current_trait_ref: None,
current_self_type: None,
self_ident: special_idents::self_,
type_self_ident: special_idents::type_self,
primitive_type_table: PrimitiveTypeTable(),
namespaces: vec!(TypeNS, ValueNS),
def_map: RefCell::new(NodeMap::new()),
export_map2: RefCell::new(NodeMap::new()),
trait_map: NodeMap::new(),
used_imports: HashSet::new(),
external_exports: DefIdSet::new(),
last_private: NodeMap::new(),
emit_errors: true,
};
this
}
/// The main resolver class.
struct Resolver<'a> {
session: &'a Session,
lang_items: &'a LanguageItems,
graph_root: NameBindings,
method_map: RefCell<FnvHashMap<(Name, DefId), ast::ExplicitSelf_>>,
structs: FnvHashMap<DefId, Vec<Name>>,
// The number of imports that are currently unresolved.
unresolved_imports: uint,
// The module that represents the current item scope.
current_module: Rc<Module>,
// The current set of local scopes, for values.
// FIXME #4948: Reuse ribs to avoid allocation.
value_ribs: RefCell<Vec<Rib>>,
// The current set of local scopes, for types.
type_ribs: RefCell<Vec<Rib>>,
// The current set of local scopes, for labels.
label_ribs: RefCell<Vec<Rib>>,
// The trait that the current context can refer to.
current_trait_ref: Option<(DefId, TraitRef)>,
// The current self type if inside an impl (used for better errors).
current_self_type: Option<Ty>,
// The ident for the keyword "self".
self_ident: Ident,
// The ident for the non-keyword "Self".
type_self_ident: Ident,
// The idents for the primitive types.
primitive_type_table: PrimitiveTypeTable,
// The four namespaces.
namespaces: Vec<Namespace> ,
def_map: DefMap,
export_map2: ExportMap2,
trait_map: TraitMap,
external_exports: ExternalExports,
last_private: LastPrivateMap,
// Whether or not to print error messages. Can be set to true
// when getting additional info for error message suggestions,
// so as to avoid printing duplicate errors
emit_errors: bool,
used_imports: HashSet<(NodeId, Namespace)>,
}
struct BuildReducedGraphVisitor<'a, 'b> {
resolver: &'a mut Resolver<'b>,
}
impl<'a, 'b> Visitor<ReducedGraphParent> for BuildReducedGraphVisitor<'a, 'b> {
fn visit_item(&mut self, item: &Item, context: ReducedGraphParent) {
let p = self.resolver.build_reduced_graph_for_item(item, context);
visit::walk_item(self, item, p);
}
fn visit_foreign_item(&mut self, foreign_item: &ForeignItem,
context: ReducedGraphParent) {
self.resolver.build_reduced_graph_for_foreign_item(foreign_item,
context.clone(),
|r| {
let mut v = BuildReducedGraphVisitor{ resolver: r };
visit::walk_foreign_item(&mut v, foreign_item, context.clone());
})
}
fn visit_view_item(&mut self, view_item: &ViewItem, context: ReducedGraphParent) {
self.resolver.build_reduced_graph_for_view_item(view_item, context);
}
fn visit_block(&mut self, block: &Block, context: ReducedGraphParent) {
let np = self.resolver.build_reduced_graph_for_block(block, context);
visit::walk_block(self, block, np);
}
}
struct UnusedImportCheckVisitor<'a, 'b> { resolver: &'a mut Resolver<'b> }
impl<'a, 'b> Visitor<()> for UnusedImportCheckVisitor<'a, 'b> {
fn visit_view_item(&mut self, vi: &ViewItem, _: ()) {
self.resolver.check_for_item_unused_imports(vi);
visit::walk_view_item(self, vi, ());
}
}
impl<'a> Resolver<'a> {
/// The main name resolution procedure.
fn resolve(&mut self, krate: &ast::Crate) {
self.build_reduced_graph(krate);
self.session.abort_if_errors();
self.resolve_imports();
self.session.abort_if_errors();
self.record_exports();
self.session.abort_if_errors();
self.resolve_crate(krate);
self.session.abort_if_errors();
self.check_for_unused_imports(krate);
}
//
// Reduced graph building
//
// Here we build the "reduced graph": the graph of the module tree without
// any imports resolved.
//
/// Constructs the reduced graph for the entire crate.
fn build_reduced_graph(&mut self, krate: &ast::Crate) {
let initial_parent =
ModuleReducedGraphParent(self.graph_root.get_module());
let mut visitor = BuildReducedGraphVisitor { resolver: self, };
visit::walk_crate(&mut visitor, krate, initial_parent);
}
/**
* Adds a new child item to the module definition of the parent node and
* returns its corresponding name bindings as well as the current parent.
* Or, if we're inside a block, creates (or reuses) an anonymous module
* corresponding to the innermost block ID and returns the name bindings
* as well as the newly-created parent.
*
* If this node does not have a module definition and we are not inside
* a block, fails.
*/
fn add_child(&self,
name: Ident,
reduced_graph_parent: ReducedGraphParent,
duplicate_checking_mode: DuplicateCheckingMode,
// For printing errors
sp: Span)
-> Rc<NameBindings> {
// If this is the immediate descendant of a module, then we add the
// child name directly. Otherwise, we create or reuse an anonymous
// module and add the child to that.
let module_ = reduced_graph_parent.module();
// Add or reuse the child.
let child = module_.children.borrow().find_copy(&name.name);
match child {
None => {
let child = Rc::new(NameBindings());
module_.children.borrow_mut().insert(name.name, child.clone());
child
}
Some(child) => {
// Enforce the duplicate checking mode:
//
// * If we're requesting duplicate module checking, check that
// there isn't a module in the module with the same name.
//
// * If we're requesting duplicate type checking, check that
// there isn't a type in the module with the same name.
//
// * If we're requesting duplicate value checking, check that
// there isn't a value in the module with the same name.
//
// * If we're requesting duplicate type checking and duplicate
// value checking, check that there isn't a duplicate type
// and a duplicate value with the same name.
//
// * If no duplicate checking was requested at all, do
// nothing.
let mut duplicate_type = NoError;
let ns = match duplicate_checking_mode {
ForbidDuplicateModules => {
if child.get_module_if_available().is_some() {
duplicate_type = ModuleError;
}
Some(TypeNS)
}
ForbidDuplicateTypes => {
match child.def_for_namespace(TypeNS) {
Some(DefMod(_)) | None => {}
Some(_) => duplicate_type = TypeError
}
Some(TypeNS)
}
ForbidDuplicateValues => {
if child.defined_in_namespace(ValueNS) {
duplicate_type = ValueError;
}
Some(ValueNS)
}
ForbidDuplicateTypesAndValues => {
let mut n = None;
match child.def_for_namespace(TypeNS) {
Some(DefMod(_)) | None => {}
Some(_) => {
n = Some(TypeNS);
duplicate_type = TypeError;
}
};
if child.defined_in_namespace(ValueNS) {
duplicate_type = ValueError;
n = Some(ValueNS);
}
n
}
OverwriteDuplicates => None
};
if duplicate_type != NoError {
// Return an error here by looking up the namespace that
// had the duplicate.
let ns = ns.unwrap();
self.resolve_error(sp,
format!("duplicate definition of {} `{}`",
namespace_error_to_str(duplicate_type),
token::get_ident(name)).as_slice());
{
let r = child.span_for_namespace(ns);
for sp in r.iter() {
self.session.span_note(*sp,
format!("first definition of {} `{}` here",
namespace_error_to_str(duplicate_type),
token::get_ident(name)).as_slice());
}
}
}
child
}
}
}
fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
// If the block has view items, we need an anonymous module.
if block.view_items.len() > 0 {
return true;
}
// Check each statement.
for statement in block.stmts.iter() {
match statement.node {
StmtDecl(declaration, _) => {
match declaration.node {
DeclItem(_) => {
return true;
}
_ => {
// Keep searching.
}
}
}
_ => {
// Keep searching.
}
}
}
// If we found neither view items nor items, we don't need to create
// an anonymous module.
return false;
}
fn get_parent_link(&mut self, parent: ReducedGraphParent, name: Ident)
-> ParentLink {
match parent {
ModuleReducedGraphParent(module_) => {
return ModuleParentLink(module_.downgrade(), name);
}
}
}
/// Constructs the reduced graph for one item.
fn build_reduced_graph_for_item(&mut self,
item: &Item,
parent: ReducedGraphParent)
-> ReducedGraphParent
{
let ident = item.ident;
let sp = item.span;
let is_public = item.vis == ast::Public;
match item.node {
ItemMod(..) => {
let name_bindings =
self.add_child(ident, parent.clone(), ForbidDuplicateModules, sp);
let parent_link = self.get_parent_link(parent, ident);
let def_id = DefId { krate: 0, node: item.id };
name_bindings.define_module(parent_link,
Some(def_id),
NormalModuleKind,
false,
item.vis == ast::Public,
sp);
ModuleReducedGraphParent(name_bindings.get_module())
}
ItemForeignMod(..) => parent,
// These items live in the value namespace.
ItemStatic(_, m, _) => {
let name_bindings =
self.add_child(ident, parent.clone(), ForbidDuplicateValues, sp);
let mutbl = m == ast::MutMutable;
name_bindings.define_value
(DefStatic(local_def(item.id), mutbl), sp, is_public);
parent
}
ItemFn(_, fn_style, _, _, _) => {
let name_bindings =
self.add_child(ident, parent.clone(), ForbidDuplicateValues, sp);
let def = DefFn(local_def(item.id), fn_style);
name_bindings.define_value(def, sp, is_public);
parent
}
// These items live in the type namespace.
ItemTy(..) => {
let name_bindings =
self.add_child(ident, parent.clone(), ForbidDuplicateTypes, sp);
name_bindings.define_type
(DefTy(local_def(item.id)), sp, is_public);
parent
}
ItemEnum(ref enum_definition, _) => {
let name_bindings =
self.add_child(ident, parent.clone(), ForbidDuplicateTypes, sp);
name_bindings.define_type
(DefTy(local_def(item.id)), sp, is_public);
for &variant in (*enum_definition).variants.iter() {
self.build_reduced_graph_for_variant(
variant,
local_def(item.id),
parent.clone(),
is_public);
}
parent
}
// These items live in both the type and value namespaces.
ItemStruct(struct_def, _) => {
// Adding to both Type and Value namespaces or just Type?
let (forbid, ctor_id) = match struct_def.ctor_id {
Some(ctor_id) => (ForbidDuplicateTypesAndValues, Some(ctor_id)),
None => (ForbidDuplicateTypes, None)
};
let name_bindings = self.add_child(ident, parent.clone(), forbid, sp);
// Define a name in the type namespace.
name_bindings.define_type(DefTy(local_def(item.id)), sp, is_public);
// If this is a newtype or unit-like struct, define a name
// in the value namespace as well
ctor_id.while_some(|cid| {
name_bindings.define_value(DefStruct(local_def(cid)), sp,
is_public);
None
});
// Record the def ID and fields of this struct.
let named_fields = struct_def.fields.iter().filter_map(|f| {
match f.node.kind {
NamedField(ident, _) => Some(ident.name),
UnnamedField(_) => None
}
}).collect();
self.structs.insert(local_def(item.id), named_fields);
parent
}
ItemImpl(_, None, ty, ref methods) => {
// If this implements an anonymous trait, then add all the
// methods within to a new module, if the type was defined
// within this module.
//
// FIXME (#3785): This is quite unsatisfactory. Perhaps we
// should modify anonymous traits to only be implementable in
// the same module that declared the type.
// Create the module and add all methods.
match ty.node {
TyPath(ref path, _, _) if path.segments.len() == 1 => {
let name = path_to_ident(path);
let parent_opt = parent.module().children.borrow()
.find_copy(&name.name);
let new_parent = match parent_opt {
// It already exists
Some(ref child) if child.get_module_if_available()
.is_some() &&
child.get_module().kind.get() ==
ImplModuleKind => {
ModuleReducedGraphParent(child.get_module())
}
// Create the module
_ => {
let name_bindings =
self.add_child(name,
parent.clone(),
ForbidDuplicateModules,
sp);
let parent_link =
self.get_parent_link(parent.clone(), ident);
let def_id = local_def(item.id);
let ns = TypeNS;
let is_public =
!name_bindings.defined_in_namespace(ns) ||
name_bindings.defined_in_public_namespace(ns);
name_bindings.define_module(parent_link,
Some(def_id),
ImplModuleKind,
false,
is_public,
sp);
ModuleReducedGraphParent(
name_bindings.get_module())
}
};
// For each method...
for method in methods.iter() {
// Add the method to the module.
let ident = method.ident;
let method_name_bindings =
self.add_child(ident,
new_parent.clone(),
ForbidDuplicateValues,
method.span);
let def = match method.explicit_self.node {
SelfStatic => {
// Static methods become
// `def_static_method`s.
DefStaticMethod(local_def(method.id),
FromImpl(local_def(
item.id)),
method.fn_style)
}
_ => {
// Non-static methods become
// `def_method`s.
DefMethod(local_def(method.id), None)
}
};
let is_public = method.vis == ast::Public;
method_name_bindings.define_value(def,
method.span,
is_public);
}
}
_ => {}
}
parent
}
ItemImpl(_, Some(_), _, _) => parent,
ItemTrait(_, _, _, ref methods) => {
let name_bindings =
self.add_child(ident, parent.clone(), ForbidDuplicateTypes, sp);
// Add all the methods within to a new module.
let parent_link = self.get_parent_link(parent.clone(), ident);
name_bindings.define_module(parent_link,
Some(local_def(item.id)),
TraitModuleKind,
false,
item.vis == ast::Public,
sp);
let module_parent = ModuleReducedGraphParent(name_bindings.
get_module());
let def_id = local_def(item.id);
// Add the names of all the methods to the trait info.
for method in methods.iter() {
let ty_m = trait_method_to_ty_method(method);
let ident = ty_m.ident;
// Add it as a name in the trait module.
let def = match ty_m.explicit_self.node {
SelfStatic => {
// Static methods become `def_static_method`s.
DefStaticMethod(local_def(ty_m.id),
FromTrait(local_def(item.id)),
ty_m.fn_style)
}
_ => {
// Non-static methods become `def_method`s.
DefMethod(local_def(ty_m.id),
Some(local_def(item.id)))
}
};
let method_name_bindings =
self.add_child(ident,
module_parent.clone(),
ForbidDuplicateValues,
ty_m.span);
method_name_bindings.define_value(def, ty_m.span, true);
self.method_map.borrow_mut().insert((ident.name, def_id),
ty_m.explicit_self.node);
}
name_bindings.define_type(DefTrait(def_id), sp, is_public);
parent
}
ItemMac(..) => parent
}
}
// Constructs the reduced graph for one variant. Variants exist in the
// type and/or value namespaces.
fn build_reduced_graph_for_variant(&mut self,
variant: &Variant,
item_id: DefId,
parent: ReducedGraphParent,
is_public: bool) {
let ident = variant.node.name;
match variant.node.kind {
TupleVariantKind(_) => {
let child = self.add_child(ident, parent, ForbidDuplicateValues, variant.span);
child.define_value(DefVariant(item_id,
local_def(variant.node.id), false),
variant.span, is_public);
}
StructVariantKind(_) => {
let child = self.add_child(ident, parent,
ForbidDuplicateTypesAndValues,
variant.span);
child.define_type(DefVariant(item_id,
local_def(variant.node.id), true),
variant.span, is_public);
// Not adding fields for variants as they are not accessed with a self receiver
self.structs.insert(local_def(variant.node.id), Vec::new());
}
}
}
/// Constructs the reduced graph for one 'view item'. View items consist
/// of imports and use directives.
fn build_reduced_graph_for_view_item(&mut self, view_item: &ViewItem,
parent: ReducedGraphParent) {
match view_item.node {
ViewItemUse(ref view_path) => {
// Extract and intern the module part of the path. For
// globs and lists, the path is found directly in the AST;
// for simple paths we have to munge the path a little.
let mut module_path = Vec::new();
match view_path.node {
ViewPathSimple(_, ref full_path, _) => {
let path_len = full_path.segments.len();
assert!(path_len != 0);
for (i, segment) in full_path.segments
.iter()
.enumerate() {
if i != path_len - 1 {
module_path.push(segment.identifier)
}
}
}
ViewPathGlob(ref module_ident_path, _) |
ViewPathList(ref module_ident_path, _, _) => {
for segment in module_ident_path.segments.iter() {
module_path.push(segment.identifier)
}
}
}
// Build up the import directives.
let module_ = parent.module();
let is_public = view_item.vis == ast::Public;
match view_path.node {
ViewPathSimple(binding, ref full_path, id) => {
let source_ident =
full_path.segments.last().unwrap().identifier;
let subclass = SingleImport(binding,
source_ident);
self.build_import_directive(&*module_,
module_path,
subclass,
view_path.span,
id,
is_public);
}
ViewPathList(_, ref source_idents, _) => {
for source_ident in source_idents.iter() {
let name = source_ident.node.name;
self.build_import_directive(
&*module_,
module_path.clone(),
SingleImport(name, name),
source_ident.span,
source_ident.node.id,
is_public);
}
}
ViewPathGlob(_, id) => {
self.build_import_directive(&*module_,
module_path,
GlobImport,
view_path.span,
id,
is_public);
}
}
}
ViewItemExternCrate(name, _, node_id) => {
// n.b. we don't need to look at the path option here, because cstore already did
match self.session.cstore.find_extern_mod_stmt_cnum(node_id) {
Some(crate_id) => {
let def_id = DefId { krate: crate_id, node: 0 };
self.external_exports.insert(def_id);
let parent_link = ModuleParentLink
(parent.module().downgrade(), name);
let external_module = Rc::new(Module::new(parent_link,
Some(def_id),
NormalModuleKind,
false,
true));
parent.module().external_module_children
.borrow_mut().insert(name.name,
external_module.clone());
self.build_reduced_graph_for_external_crate(
external_module);
}
None => {} // Ignore.
}
}
}
}
/// Constructs the reduced graph for one foreign item.
fn build_reduced_graph_for_foreign_item(&mut self,
foreign_item: &ForeignItem,
parent: ReducedGraphParent,
f: |&mut Resolver|) {
let name = foreign_item.ident;
let is_public = foreign_item.vis == ast::Public;
let name_bindings =
self.add_child(name, parent, ForbidDuplicateValues,
foreign_item.span);
match foreign_item.node {
ForeignItemFn(_, ref generics) => {
let def = DefFn(local_def(foreign_item.id), UnsafeFn);
name_bindings.define_value(def, foreign_item.span, is_public);
self.with_type_parameter_rib(
HasTypeParameters(generics,
foreign_item.id,
0,
NormalRibKind),
f);
}
ForeignItemStatic(_, m) => {
let def = DefStatic(local_def(foreign_item.id), m);
name_bindings.define_value(def, foreign_item.span, is_public);
f(self)
}
}
}
fn build_reduced_graph_for_block(&mut self,
block: &Block,
parent: ReducedGraphParent)
-> ReducedGraphParent
{
if self.block_needs_anonymous_module(block) {
let block_id = block.id;
debug!("(building reduced graph for block) creating a new \
anonymous module for block {}",
block_id);
let parent_module = parent.module();
let new_module = Rc::new(Module::new(
BlockParentLink(parent_module.downgrade(), block_id),
None,
AnonymousModuleKind,
false,
false));
parent_module.anonymous_children.borrow_mut()
.insert(block_id, new_module.clone());
ModuleReducedGraphParent(new_module)
} else {
parent
}
}
fn handle_external_def(&mut self,
def: Def,
vis: Visibility,
child_name_bindings: &NameBindings,
final_ident: &str,
ident: Ident,
new_parent: ReducedGraphParent) {
debug!("(building reduced graph for \
external crate) building external def, priv {:?}",
vis);
let is_public = vis == ast::Public;
let is_exported = is_public && match new_parent {
ModuleReducedGraphParent(ref module) => {
match module.def_id.get() {
None => true,
Some(did) => self.external_exports.contains(&did)
}
}
};
if is_exported {
self.external_exports.insert(def_id_of_def(def));
}
match def {
DefMod(def_id) | DefForeignMod(def_id) | DefStruct(def_id) |
DefTy(def_id) => {
let type_def = child_name_bindings.type_def.borrow().clone();
match type_def {
Some(TypeNsDef { module_def: Some(module_def), .. }) => {
debug!("(building reduced graph for external crate) \
already created module");
module_def.def_id.set(Some(def_id));
}
Some(_) | None => {
debug!("(building reduced graph for \
external crate) building module \
{}", final_ident);
let parent_link = self.get_parent_link(new_parent.clone(), ident);
child_name_bindings.define_module(parent_link,
Some(def_id),
NormalModuleKind,
true,
is_public,
DUMMY_SP);
}
}
}
_ => {}
}
match def {
DefMod(_) | DefForeignMod(_) => {}
DefVariant(enum_did, variant_id, is_struct) => {
debug!("(building reduced graph for external crate) building \
variant {}",
final_ident);
// If this variant is public, then it was publicly reexported,
// otherwise we need to inherit the visibility of the enum
// definition.
let is_exported = is_public ||
self.external_exports.contains(&enum_did);
if is_struct {
child_name_bindings.define_type(def, DUMMY_SP, is_exported);
// Not adding fields for variants as they are not accessed with a self receiver
self.structs.insert(variant_id, Vec::new());
} else {
child_name_bindings.define_value(def, DUMMY_SP, is_exported);
}
}
DefFn(..) | DefStaticMethod(..) | DefStatic(..) => {
debug!("(building reduced graph for external \
crate) building value (fn/static) {}", final_ident);
child_name_bindings.define_value(def, DUMMY_SP, is_public);
}
DefTrait(def_id) => {
debug!("(building reduced graph for external \
crate) building type {}", final_ident);
// If this is a trait, add all the method names
// to the trait info.
let method_def_ids =
csearch::get_trait_method_def_ids(&self.session.cstore, def_id);
for &method_def_id in method_def_ids.iter() {
let (method_name, explicit_self) =
csearch::get_method_name_and_explicit_self(&self.session.cstore,
method_def_id);
debug!("(building reduced graph for \
external crate) ... adding \
trait method '{}'",
token::get_ident(method_name));
self.method_map.borrow_mut().insert((method_name.name, def_id), explicit_self);
if is_exported {
self.external_exports.insert(method_def_id);
}
}
child_name_bindings.define_type(def, DUMMY_SP, is_public);
// Define a module if necessary.
let parent_link = self.get_parent_link(new_parent, ident);
child_name_bindings.set_module_kind(parent_link,
Some(def_id),
TraitModuleKind,
true,
is_public,
DUMMY_SP)
}
DefTy(_) => {
debug!("(building reduced graph for external \
crate) building type {}", final_ident);
child_name_bindings.define_type(def, DUMMY_SP, is_public);
}
DefStruct(def_id) => {
debug!("(building reduced graph for external \
crate) building type and value for {}",
final_ident);
child_name_bindings.define_type(def, DUMMY_SP, is_public);
let fields = csearch::get_struct_fields(&self.session.cstore, def_id).iter().map(|f| {
f.name
}).collect::<Vec<_>>();
if fields.len() == 0 {
child_name_bindings.define_value(def, DUMMY_SP, is_public);
}
// Record the def ID and fields of this struct.
self.structs.insert(def_id, fields);
}
DefMethod(..) => {
debug!("(building reduced graph for external crate) \
ignoring {:?}", def);
// Ignored; handled elsewhere.
}
DefArg(..) | DefLocal(..) | DefPrimTy(..) |
DefTyParam(..) | DefBinding(..) |
DefUse(..) | DefUpvar(..) | DefRegion(..) |
DefTyParamBinder(..) | DefLabel(..) | DefSelfTy(..) => {
fail!("didn't expect `{:?}`", def);
}
}
}
/// Builds the reduced graph for a single item in an external crate.
fn build_reduced_graph_for_external_crate_def(&mut self,
root: Rc<Module>,
def_like: DefLike,
ident: Ident,
visibility: Visibility) {
match def_like {
DlDef(def) => {
// Add the new child item, if necessary.
match def {
DefForeignMod(def_id) => {
// Foreign modules have no names. Recur and populate
// eagerly.
csearch::each_child_of_item(&self.session.cstore,
def_id,
|def_like,
child_ident,
vis| {
self.build_reduced_graph_for_external_crate_def(
root.clone(),
def_like,
child_ident,
vis)
});
}
_ => {
let child_name_bindings =
self.add_child(ident,
ModuleReducedGraphParent(root.clone()),
OverwriteDuplicates,
DUMMY_SP);
self.handle_external_def(def,
visibility,
&*child_name_bindings,
token::get_ident(ident).get(),
ident,
ModuleReducedGraphParent(root));
}
}
}
DlImpl(def) => {
// We only process static methods of impls here.
match csearch::get_type_name_if_impl(&self.session.cstore, def) {
None => {}
Some(final_ident) => {
let static_methods_opt =
csearch::get_static_methods_if_impl(&self.session.cstore, def);
match static_methods_opt {
Some(ref static_methods) if
static_methods.len() >= 1 => {
debug!("(building reduced graph for \
external crate) processing \
static methods for type name {}",
token::get_ident(final_ident));
let child_name_bindings =
self.add_child(
final_ident,
ModuleReducedGraphParent(root.clone()),
OverwriteDuplicates,
DUMMY_SP);
// Process the static methods. First,
// create the module.
let type_module;
let type_def = child_name_bindings.type_def.borrow().clone();
match type_def {
Some(TypeNsDef {
module_def: Some(module_def),
..
}) => {
// We already have a module. This
// is OK.
type_module = module_def;
// Mark it as an impl module if
// necessary.
type_module.kind.set(ImplModuleKind);
}
Some(_) | None => {
let parent_link =
self.get_parent_link(ModuleReducedGraphParent(root),
final_ident);
child_name_bindings.define_module(
parent_link,
Some(def),
ImplModuleKind,
true,
true,
DUMMY_SP);
type_module =
child_name_bindings.
get_module();
}
}
// Add each static method to the module.
let new_parent =
ModuleReducedGraphParent(type_module);
for static_method_info in
static_methods.iter() {
let ident = static_method_info.ident;
debug!("(building reduced graph for \
external crate) creating \
static method '{}'",
token::get_ident(ident));
let method_name_bindings =
self.add_child(ident,
new_parent.clone(),
OverwriteDuplicates,
DUMMY_SP);
let def = DefFn(
static_method_info.def_id,
static_method_info.fn_style);
method_name_bindings.define_value(
def, DUMMY_SP,
visibility == ast::Public);
}
}
// Otherwise, do nothing.
Some(_) | None => {}
}
}
}
}
DlField => {
debug!("(building reduced graph for external crate) \
ignoring field");
}
}
}
/// Builds the reduced graph rooted at the given external module.
fn populate_external_module(&mut self, module: Rc<Module>) {
debug!("(populating external module) attempting to populate {}",
self.module_to_str(&*module));
let def_id = match module.def_id.get() {
None => {
debug!("(populating external module) ... no def ID!");
return
}
Some(def_id) => def_id,
};
csearch::each_child_of_item(&self.session.cstore,
def_id,
|def_like, child_ident, visibility| {
debug!("(populating external module) ... found ident: {}",
token::get_ident(child_ident));
self.build_reduced_graph_for_external_crate_def(module.clone(),
def_like,
child_ident,
visibility)
});
module.populated.set(true)
}
/// Ensures that the reduced graph rooted at the given external module
/// is built, building it if it is not.
fn populate_module_if_necessary(&mut self, module: &Rc<Module>) {
if !module.populated.get() {
self.populate_external_module(module.clone())
}
assert!(module.populated.get())
}
/// Builds the reduced graph rooted at the 'use' directive for an external
/// crate.
fn build_reduced_graph_for_external_crate(&mut self, root: Rc<Module>) {
csearch::each_top_level_item_of_crate(&self.session.cstore,
root.def_id
.get()
.unwrap()
.krate,
|def_like, ident, visibility| {
self.build_reduced_graph_for_external_crate_def(root.clone(),
def_like,
ident,
visibility)
});
}
/// Creates and adds an import directive to the given module.
fn build_import_directive(&mut self,
module_: &Module,
module_path: Vec<Ident> ,
subclass: ImportDirectiveSubclass,
span: Span,
id: NodeId,
is_public: bool) {
module_.imports.borrow_mut().push(ImportDirective::new(module_path,
subclass,
span, id,
is_public));
self.unresolved_imports += 1;
// Bump the reference count on the name. Or, if this is a glob, set
// the appropriate flag.
match subclass {
SingleImport(target, _) => {
debug!("(building import directive) building import \
directive: {}::{}",
self.idents_to_str(module_.imports.borrow().last().unwrap()
.module_path.as_slice()),
token::get_ident(target));
let mut import_resolutions = module_.import_resolutions
.borrow_mut();
match import_resolutions.find_mut(&target.name) {
Some(resolution) => {
debug!("(building import directive) bumping \
reference");
resolution.outstanding_references += 1;
// the source of this name is different now
resolution.type_id = id;
resolution.value_id = id;
resolution.is_public = is_public;
return;
}
None => {}
}
debug!("(building import directive) creating new");
let mut resolution = ImportResolution::new(id, is_public);
resolution.outstanding_references = 1;
import_resolutions.insert(target.name, resolution);
}
GlobImport => {
// Set the glob flag. This tells us that we don't know the
// module's exports ahead of time.
module_.glob_count.set(module_.glob_count.get() + 1);
}
}
}
// Import resolution
//
// This is a fixed-point algorithm. We resolve imports until our efforts
// are stymied by an unresolved import; then we bail out of the current
// module and continue. We terminate successfully once no more imports
// remain or unsuccessfully when no forward progress in resolving imports
// is made.
/// Resolves all imports for the crate. This method performs the fixed-
/// point iteration.
fn resolve_imports(&mut self) {
let mut i = 0;
let mut prev_unresolved_imports = 0;
loop {
debug!("(resolving imports) iteration {}, {} imports left",
i, self.unresolved_imports);
let module_root = self.graph_root.get_module();
self.resolve_imports_for_module_subtree(module_root.clone());
if self.unresolved_imports == 0 {
debug!("(resolving imports) success");
break;
}
if self.unresolved_imports == prev_unresolved_imports {
self.report_unresolved_imports(module_root);
break;
}
i += 1;
prev_unresolved_imports = self.unresolved_imports;
}
}
/// Attempts to resolve imports for the given module and all of its
/// submodules.
fn resolve_imports_for_module_subtree(&mut self, module_: Rc<Module>) {
debug!("(resolving imports for module subtree) resolving {}",
self.module_to_str(&*module_));
self.resolve_imports_for_module(module_.clone());
self.populate_module_if_necessary(&module_);
for (_, child_node) in module_.children.borrow().iter() {
match child_node.get_module_if_available() {
None => {
// Nothing to do.
}
Some(child_module) => {
self.resolve_imports_for_module_subtree(child_module);
}
}
}
for (_, child_module) in module_.anonymous_children.borrow().iter() {
self.resolve_imports_for_module_subtree(child_module.clone());
}
}
/// Attempts to resolve imports for the given module only.
fn resolve_imports_for_module(&mut self, module: Rc<Module>) {
if module.all_imports_resolved() {
debug!("(resolving imports for module) all imports resolved for \
{}",
self.module_to_str(&*module));
return;
}
let imports = module.imports.borrow();
let import_count = imports.len();
while module.resolved_import_count.get() < import_count {
let import_index = module.resolved_import_count.get();
let import_directive = imports.get(import_index);
match self.resolve_import_for_module(module.clone(),
import_directive) {
Failed => {
// We presumably emitted an error. Continue.
let msg = format!("failed to resolve import `{}`",
self.import_path_to_str(
import_directive.module_path
.as_slice(),
import_directive.subclass));
self.resolve_error(import_directive.span, msg.as_slice());
}
Indeterminate => {
// Bail out. We'll come around next time.
break;
}
Success(()) => {
// Good. Continue.
}
}
module.resolved_import_count
.set(module.resolved_import_count.get() + 1);
}
}
fn idents_to_str(&self, idents: &[Ident]) -> StrBuf {
let mut first = true;
let mut result = StrBuf::new();
for ident in idents.iter() {
if first {
first = false
} else {
result.push_str("::")
}
result.push_str(token::get_ident(*ident).get());
};
result
}
fn path_idents_to_str(&self, path: &Path) -> StrBuf {
let identifiers: Vec<ast::Ident> = path.segments
.iter()
.map(|seg| seg.identifier)
.collect();
self.idents_to_str(identifiers.as_slice())
}
fn import_directive_subclass_to_str(&mut self,
subclass: ImportDirectiveSubclass)
-> StrBuf {
match subclass {
SingleImport(_, source) => {
token::get_ident(source).get().to_strbuf()
}
GlobImport => "*".to_strbuf()
}
}
fn import_path_to_str(&mut self,
idents: &[Ident],
subclass: ImportDirectiveSubclass)
-> StrBuf {
if idents.is_empty() {
self.import_directive_subclass_to_str(subclass)
} else {
(format!("{}::{}",
self.idents_to_str(idents),
self.import_directive_subclass_to_str(
subclass))).to_strbuf()
}
}
/// Attempts to resolve the given import. The return value indicates
/// failure if we're certain the name does not exist, indeterminate if we
/// don't know whether the name exists at the moment due to other
/// currently-unresolved imports, or success if we know the name exists.
/// If successful, the resolved bindings are written into the module.
fn resolve_import_for_module(&mut self,
module_: Rc<Module>,
import_directive: &ImportDirective)
-> ResolveResult<()> {
let mut resolution_result = Failed;
let module_path = &import_directive.module_path;
debug!("(resolving import for module) resolving import `{}::...` in \
`{}`",
self.idents_to_str(module_path.as_slice()),
self.module_to_str(&*module_));
// First, resolve the module path for the directive, if necessary.
let container = if module_path.len() == 0 {
// Use the crate root.
Some((self.graph_root.get_module(), LastMod(AllPublic)))
} else {
match self.resolve_module_path(module_.clone(),
module_path.as_slice(),
DontUseLexicalScope,
import_directive.span,
ImportSearch) {
Failed => None,
Indeterminate => {
resolution_result = Indeterminate;
None
}
Success(container) => Some(container),
}
};
match container {
None => {}
Some((containing_module, lp)) => {
// We found the module that the target is contained
// within. Attempt to resolve the import within it.
match import_directive.subclass {
SingleImport(target, source) => {
resolution_result =
self.resolve_single_import(&*module_,
containing_module,
target,
source,
import_directive,
lp);
}
GlobImport => {
resolution_result =
self.resolve_glob_import(&*module_,
containing_module,
import_directive.id,
import_directive.is_public,
lp);
}
}
}
}
// Decrement the count of unresolved imports.
match resolution_result {
Success(()) => {
assert!(self.unresolved_imports >= 1);
self.unresolved_imports -= 1;
}
_ => {
// Nothing to do here; just return the error.
}
}
// Decrement the count of unresolved globs if necessary. But only if
// the resolution result is indeterminate -- otherwise we'll stop
// processing imports here. (See the loop in
// resolve_imports_for_module.)
if !resolution_result.indeterminate() {
match import_directive.subclass {
GlobImport => {
assert!(module_.glob_count.get() >= 1);
module_.glob_count.set(module_.glob_count.get() - 1);
}
SingleImport(..) => {
// Ignore.
}
}
}
return resolution_result;
}
fn create_name_bindings_from_module(module: Rc<Module>) -> NameBindings {
NameBindings {
type_def: RefCell::new(Some(TypeNsDef {
is_public: false,
module_def: Some(module),
type_def: None,
type_span: None
})),
value_def: RefCell::new(None),
}
}
fn resolve_single_import(&mut self,
module_: &Module,
containing_module: Rc<Module>,
target: Ident,
source: Ident,
directive: &ImportDirective,
lp: LastPrivate)
-> ResolveResult<()> {
debug!("(resolving single import) resolving `{}` = `{}::{}` from \
`{}` id {}, last private {:?}",
token::get_ident(target),
self.module_to_str(&*containing_module),
token::get_ident(source),
self.module_to_str(module_),
directive.id,
lp);
let lp = match lp {
LastMod(lp) => lp,
LastImport {..} => {
self.session
.span_bug(directive.span,
"not expecting Import here, must be LastMod")
}
};
// We need to resolve both namespaces for this to succeed.
//
let mut value_result = UnknownResult;
let mut type_result = UnknownResult;
// Search for direct children of the containing module.
self.populate_module_if_necessary(&containing_module);
match containing_module.children.borrow().find(&source.name) {
None => {
// Continue.
}
Some(ref child_name_bindings) => {
if child_name_bindings.defined_in_namespace(ValueNS) {
debug!("(resolving single import) found value binding");
value_result = BoundResult(containing_module.clone(),
(*child_name_bindings).clone());
}
if child_name_bindings.defined_in_namespace(TypeNS) {
debug!("(resolving single import) found type binding");
type_result = BoundResult(containing_module.clone(),
(*child_name_bindings).clone());
}
}
}
// Unless we managed to find a result in both namespaces (unlikely),
// search imports as well.
let mut value_used_reexport = false;
let mut type_used_reexport = false;
match (value_result.clone(), type_result.clone()) {
(BoundResult(..), BoundResult(..)) => {} // Continue.
_ => {
// If there is an unresolved glob at this point in the
// containing module, bail out. We don't know enough to be
// able to resolve this import.
if containing_module.glob_count.get() > 0 {
debug!("(resolving single import) unresolved glob; \
bailing out");
return Indeterminate;
}
// Now search the exported imports within the containing module.
match containing_module.import_resolutions.borrow().find(&source.name) {
None => {
debug!("(resolving single import) no import");
// The containing module definitely doesn't have an
// exported import with the name in question. We can
// therefore accurately report that the names are
// unbound.
if value_result.is_unknown() {
value_result = UnboundResult;
}
if type_result.is_unknown() {
type_result = UnboundResult;
}
}
Some(import_resolution)
if import_resolution.outstanding_references == 0 => {
fn get_binding(this: &mut Resolver,
import_resolution: &ImportResolution,
namespace: Namespace)
-> NamespaceResult {
// Import resolutions must be declared with "pub"
// in order to be exported.
if !import_resolution.is_public {
return UnboundResult;
}
match import_resolution.
target_for_namespace(namespace) {
None => {
return UnboundResult;
}
Some(Target {target_module, bindings}) => {
debug!("(resolving single import) found \
import in ns {:?}", namespace);
let id = import_resolution.id(namespace);
this.used_imports.insert((id, namespace));
return BoundResult(target_module, bindings);
}
}
}
// The name is an import which has been fully
// resolved. We can, therefore, just follow it.
if value_result.is_unknown() {
value_result = get_binding(self, import_resolution,
ValueNS);
value_used_reexport = import_resolution.is_public;
}
if type_result.is_unknown() {
type_result = get_binding(self, import_resolution,
TypeNS);
type_used_reexport = import_resolution.is_public;
}
}
Some(_) => {
// The import is unresolved. Bail out.
debug!("(resolving single import) unresolved import; \
bailing out");
return Indeterminate;
}
}
}
}
// If we didn't find a result in the type namespace, search the
// external modules.
let mut value_used_public = false;
let mut type_used_public = false;
match type_result {
BoundResult(..) => {}
_ => {
match containing_module.external_module_children.borrow_mut()
.find_copy(&source.name) {
None => {} // Continue.
Some(module) => {
debug!("(resolving single import) found external \
module");
let name_bindings =
Rc::new(Resolver::create_name_bindings_from_module(
module));
type_result = BoundResult(containing_module.clone(),
name_bindings);
type_used_public = true;
}
}
}
}
// We've successfully resolved the import. Write the results in.
let mut import_resolutions = module_.import_resolutions.borrow_mut();
let import_resolution = import_resolutions.get_mut(&target.name);
match value_result {
BoundResult(ref target_module, ref name_bindings) => {
debug!("(resolving single import) found value target");
import_resolution.value_target = Some(Target::new(target_module.clone(),
name_bindings.clone()));
import_resolution.value_id = directive.id;
import_resolution.is_public = directive.is_public;
value_used_public = name_bindings.defined_in_public_namespace(ValueNS);
}
UnboundResult => { /* Continue. */ }
UnknownResult => {
fail!("value result should be known at this point");
}
}
match type_result {
BoundResult(ref target_module, ref name_bindings) => {
debug!("(resolving single import) found type target: {:?}",
{ name_bindings.type_def.borrow().clone().unwrap().type_def });
import_resolution.type_target =
Some(Target::new(target_module.clone(), name_bindings.clone()));
import_resolution.type_id = directive.id;
import_resolution.is_public = directive.is_public;
type_used_public = name_bindings.defined_in_public_namespace(TypeNS);
}
UnboundResult => { /* Continue. */ }
UnknownResult => {
fail!("type result should be known at this point");
}
}
if value_result.is_unbound() && type_result.is_unbound() {
let msg = format!("unresolved import: there is no \
`{}` in `{}`",
token::get_ident(source),
self.module_to_str(&*containing_module));
self.resolve_error(directive.span, msg.as_slice());
return Failed;
}
let value_used_public = value_used_reexport || value_used_public;
let type_used_public = type_used_reexport || type_used_public;
assert!(import_resolution.outstanding_references >= 1);
import_resolution.outstanding_references -= 1;
// record what this import resolves to for later uses in documentation,
// this may resolve to either a value or a type, but for documentation
// purposes it's good enough to just favor one over the other.
let value_private = match import_resolution.value_target {
Some(ref target) => {
let def = target.bindings.def_for_namespace(ValueNS).unwrap();
self.def_map.borrow_mut().insert(directive.id, def);
let did = def_id_of_def(def);
if value_used_public {Some(lp)} else {Some(DependsOn(did))}
},
// AllPublic here and below is a dummy value, it should never be used because
// _exists is false.
None => None,
};
let type_private = match import_resolution.type_target {
Some(ref target) => {
let def = target.bindings.def_for_namespace(TypeNS).unwrap();
self.def_map.borrow_mut().insert(directive.id, def);
let did = def_id_of_def(def);
if type_used_public {Some(lp)} else {Some(DependsOn(did))}
},
None => None,
};
self.last_private.insert(directive.id, LastImport{value_priv: value_private,
value_used: Used,
type_priv: type_private,
type_used: Used});
debug!("(resolving single import) successfully resolved import");
return Success(());
}
// Resolves a glob import. Note that this function cannot fail; it either
// succeeds or bails out (as importing * from an empty module or a module
// that exports nothing is valid).
fn resolve_glob_import(&mut self,
module_: &Module,
containing_module: Rc<Module>,
id: NodeId,
is_public: bool,
lp: LastPrivate)
-> ResolveResult<()> {
// This function works in a highly imperative manner; it eagerly adds
// everything it can to the list of import resolutions of the module
// node.
debug!("(resolving glob import) resolving glob import {}", id);
// We must bail out if the node has unresolved imports of any kind
// (including globs).
if !(*containing_module).all_imports_resolved() {
debug!("(resolving glob import) target module has unresolved \
imports; bailing out");
return Indeterminate;
}
assert_eq!(containing_module.glob_count.get(), 0);
// Add all resolved imports from the containing module.
let import_resolutions = containing_module.import_resolutions
.borrow();
for (ident, target_import_resolution) in import_resolutions.iter() {
debug!("(resolving glob import) writing module resolution \
{:?} into `{}`",
target_import_resolution.type_target.is_none(),
self.module_to_str(module_));
if !target_import_resolution.is_public {
debug!("(resolving glob import) nevermind, just kidding");
continue
}
// Here we merge two import resolutions.
let mut import_resolutions = module_.import_resolutions.borrow_mut();
match import_resolutions.find_mut(ident) {
Some(dest_import_resolution) => {
// Merge the two import resolutions at a finer-grained
// level.
match target_import_resolution.value_target {
None => {
// Continue.
}
Some(ref value_target) => {
dest_import_resolution.value_target =
Some(value_target.clone());
}
}
match target_import_resolution.type_target {
None => {
// Continue.
}
Some(ref type_target) => {
dest_import_resolution.type_target =
Some(type_target.clone());
}
}
dest_import_resolution.is_public = is_public;
continue;
}
None => {}
}
// Simple: just copy the old import resolution.
let mut new_import_resolution = ImportResolution::new(id, is_public);
new_import_resolution.value_target =
target_import_resolution.value_target.clone();
new_import_resolution.type_target =
target_import_resolution.type_target.clone();
import_resolutions.insert(*ident, new_import_resolution);
}
// Add all children from the containing module.
self.populate_module_if_necessary(&containing_module);
for (&name, name_bindings) in containing_module.children
.borrow().iter() {
self.merge_import_resolution(module_, containing_module.clone(),
id, is_public,
name, name_bindings.clone());
}
// Add external module children from the containing module.
for (&name, module) in containing_module.external_module_children
.borrow().iter() {
let name_bindings =
Rc::new(Resolver::create_name_bindings_from_module(module.clone()));
self.merge_import_resolution(module_, containing_module.clone(),
id, is_public,
name, name_bindings);
}
// Record the destination of this import
match containing_module.def_id.get() {
Some(did) => {
self.def_map.borrow_mut().insert(id, DefMod(did));
self.last_private.insert(id, lp);
}
None => {}
}
debug!("(resolving glob import) successfully resolved import");
return Success(());
}
fn merge_import_resolution(&mut self,
module_: &Module,
containing_module: Rc<Module>,
id: NodeId,
is_public: bool,
name: Name,
name_bindings: Rc<NameBindings>) {
let mut import_resolutions = module_.import_resolutions.borrow_mut();
let dest_import_resolution = import_resolutions.find_or_insert_with(name, |_| {
// Create a new import resolution from this child.
ImportResolution::new(id, is_public)
});
debug!("(resolving glob import) writing resolution `{}` in `{}` \
to `{}`",
token::get_name(name).get().to_str(),
self.module_to_str(&*containing_module),
self.module_to_str(module_));
// Merge the child item into the import resolution.
if name_bindings.defined_in_public_namespace(ValueNS) {
debug!("(resolving glob import) ... for value target");
dest_import_resolution.value_target =
Some(Target::new(containing_module.clone(), name_bindings.clone()));
dest_import_resolution.value_id = id;
}
if name_bindings.defined_in_public_namespace(TypeNS) {
debug!("(resolving glob import) ... for type target");
dest_import_resolution.type_target =
Some(Target::new(containing_module, name_bindings.clone()));
dest_import_resolution.type_id = id;
}
dest_import_resolution.is_public = is_public;
}
/// Resolves the given module path from the given root `module_`.
fn resolve_module_path_from_root(&mut self,
module_: Rc<Module>,
module_path: &[Ident],
index: uint,
span: Span,
name_search_type: NameSearchType,
lp: LastPrivate)
-> ResolveResult<(Rc<Module>, LastPrivate)> {
let mut search_module = module_;
let mut index = index;
let module_path_len = module_path.len();
let mut closest_private = lp;
// Resolve the module part of the path. This does not involve looking
// upward though scope chains; we simply resolve names directly in
// modules as we go.
while index < module_path_len {
let name = module_path[index];
match self.resolve_name_in_module(search_module.clone(),
name.name,
TypeNS,
name_search_type,
false) {
Failed => {
let segment_name = token::get_ident(name);
let module_name = self.module_to_str(&*search_module);
if "???" == module_name.as_slice() {
let span = Span {
lo: span.lo,
hi: span.lo + Pos::from_uint(segment_name.get().len()),
expn_info: span.expn_info,
};
self.resolve_error(span,
format!("unresolved import. maybe \
a missing `extern crate \
{}`?",
segment_name).as_slice());
return Failed;
}
self.resolve_error(span,
format!("unresolved import: could not \
find `{}` in `{}`.",
segment_name,
module_name).as_slice());
return Failed;
}
Indeterminate => {
debug!("(resolving module path for import) module \
resolution is indeterminate: {}",
token::get_ident(name));
return Indeterminate;
}
Success((target, used_proxy)) => {
// Check to see whether there are type bindings, and, if
// so, whether there is a module within.
match *target.bindings.type_def.borrow() {
Some(ref type_def) => {
match type_def.module_def {
None => {
// Not a module.
self.resolve_error(
span,
format!("not a module `{}`",
token::get_ident(name))
.as_slice());
return Failed;
}
Some(ref module_def) => {
// If we're doing the search for an
// import, do not allow traits and impls
// to be selected.
match (name_search_type,
module_def.kind.get()) {
(ImportSearch, TraitModuleKind) |
(ImportSearch, ImplModuleKind) => {
self.resolve_error(
span,
"cannot import from a trait \
or type implementation");
return Failed;
}
(_, _) => {
search_module = module_def.clone();
// Keep track of the closest
// private module used when
// resolving this import chain.
if !used_proxy &&
!search_module.is_public {
match search_module.def_id
.get() {
Some(did) => {
closest_private =
LastMod(DependsOn(did));
}
None => {}
}
}
}
}
}
}
}
None => {
// There are no type bindings at all.
self.resolve_error(
span,
format!("not a module `{}`",
token::get_ident(name)).as_slice());
return Failed;
}
}
}
}
index += 1;
}
return Success((search_module, closest_private));
}
/// Attempts to resolve the module part of an import directive or path
/// rooted at the given module.
///
/// On success, returns the resolved module, and the closest *private*
/// module found to the destination when resolving this path.
fn resolve_module_path(&mut self,
module_: Rc<Module>,
module_path: &[Ident],
use_lexical_scope: UseLexicalScopeFlag,
span: Span,
name_search_type: NameSearchType)
-> ResolveResult<(Rc<Module>, LastPrivate)> {
let module_path_len = module_path.len();
assert!(module_path_len > 0);
debug!("(resolving module path for import) processing `{}` rooted at \
`{}`",
self.idents_to_str(module_path),
self.module_to_str(&*module_));
// Resolve the module prefix, if any.
let module_prefix_result = self.resolve_module_prefix(module_.clone(),
module_path);
let search_module;
let start_index;
let last_private;
match module_prefix_result {
Failed => {
let mpath = self.idents_to_str(module_path);
match mpath.as_slice().rfind(':') {
Some(idx) => {
self.resolve_error(
span,
format!("unresolved import: could not find `{}` \
in `{}`",
// idx +- 1 to account for the colons on \
// either side
mpath.as_slice().slice_from(idx + 1),
mpath.as_slice()
.slice_to(idx - 1)).as_slice());
},
None => (),
};
return Failed;
}
Indeterminate => {
debug!("(resolving module path for import) indeterminate; \
bailing");
return Indeterminate;
}
Success(NoPrefixFound) => {
// There was no prefix, so we're considering the first element
// of the path. How we handle this depends on whether we were
// instructed to use lexical scope or not.
match use_lexical_scope {
DontUseLexicalScope => {
// This is a crate-relative path. We will start the
// resolution process at index zero.
search_module = self.graph_root.get_module();
start_index = 0;
last_private = LastMod(AllPublic);
}
UseLexicalScope => {
// This is not a crate-relative path. We resolve the
// first component of the path in the current lexical
// scope and then proceed to resolve below that.
let result = self.resolve_module_in_lexical_scope(
module_,
module_path[0]);
match result {
Failed => {
self.resolve_error(span, "unresolved name");
return Failed;
}
Indeterminate => {
debug!("(resolving module path for import) \
indeterminate; bailing");
return Indeterminate;
}
Success(containing_module) => {
search_module = containing_module;
start_index = 1;
last_private = LastMod(AllPublic);
}
}
}
}
}
Success(PrefixFound(ref containing_module, index)) => {
search_module = containing_module.clone();
start_index = index;
last_private = LastMod(DependsOn(containing_module.def_id
.get()
.unwrap()));
}
}
self.resolve_module_path_from_root(search_module,
module_path,
start_index,
span,
name_search_type,
last_private)
}
/// Invariant: This must only be called during main resolution, not during
/// import resolution.
fn resolve_item_in_lexical_scope(&mut self,
module_: Rc<Module>,
name: Ident,
namespace: Namespace)
-> ResolveResult<(Target, bool)> {
debug!("(resolving item in lexical scope) resolving `{}` in \
namespace {:?} in `{}`",
token::get_ident(name),
namespace,
self.module_to_str(&*module_));
// The current module node is handled specially. First, check for
// its immediate children.
self.populate_module_if_necessary(&module_);
match module_.children.borrow().find(&name.name) {
Some(name_bindings)
if name_bindings.defined_in_namespace(namespace) => {
debug!("top name bindings succeeded");
return Success((Target::new(module_.clone(), name_bindings.clone()),
false));
}
Some(_) | None => { /* Not found; continue. */ }
}
// Now check for its import directives. We don't have to have resolved
// all its imports in the usual way; this is because chains of
// adjacent import statements are processed as though they mutated the
// current scope.
match module_.import_resolutions.borrow().find(&name.name) {
None => {
// Not found; continue.
}
Some(import_resolution) => {
match (*import_resolution).target_for_namespace(namespace) {
None => {
// Not found; continue.
debug!("(resolving item in lexical scope) found \
import resolution, but not in namespace {:?}",
namespace);
}
Some(target) => {
debug!("(resolving item in lexical scope) using \
import resolution");
self.used_imports.insert((import_resolution.id(namespace), namespace));
return Success((target, false));
}
}
}
}
// Search for external modules.
if namespace == TypeNS {
match module_.external_module_children.borrow().find_copy(&name.name) {
None => {}
Some(module) => {
let name_bindings =
Rc::new(Resolver::create_name_bindings_from_module(module));
debug!("lower name bindings succeeded");
return Success((Target::new(module_, name_bindings), false));
}
}
}
// Finally, proceed up the scope chain looking for parent modules.
let mut search_module = module_;
loop {
// Go to the next parent.
match search_module.parent_link.clone() {
NoParentLink => {
// No more parents. This module was unresolved.
debug!("(resolving item in lexical scope) unresolved \
module");
return Failed;
}
ModuleParentLink(parent_module_node, _) => {
match search_module.kind.get() {
NormalModuleKind => {
// We stop the search here.
debug!("(resolving item in lexical \
scope) unresolved module: not \
searching through module \
parents");
return Failed;
}
ExternModuleKind |
TraitModuleKind |
ImplModuleKind |
AnonymousModuleKind => {
search_module = parent_module_node.upgrade().unwrap();
}
}
}
BlockParentLink(ref parent_module_node, _) => {
search_module = parent_module_node.upgrade().unwrap();
}
}
// Resolve the name in the parent module.
match self.resolve_name_in_module(search_module.clone(),
name.name,
namespace,
PathSearch,
true) {
Failed => {
// Continue up the search chain.
}
Indeterminate => {
// We couldn't see through the higher scope because of an
// unresolved import higher up. Bail.
debug!("(resolving item in lexical scope) indeterminate \
higher scope; bailing");
return Indeterminate;
}
Success((target, used_reexport)) => {
// We found the module.
debug!("(resolving item in lexical scope) found name \
in module, done");
return Success((target, used_reexport));
}
}
}
}
/// Resolves a module name in the current lexical scope.
fn resolve_module_in_lexical_scope(&mut self,
module_: Rc<Module>,
name: Ident)
-> ResolveResult<Rc<Module>> {
// If this module is an anonymous module, resolve the item in the
// lexical scope. Otherwise, resolve the item from the crate root.
let resolve_result = self.resolve_item_in_lexical_scope(
module_, name, TypeNS);
match resolve_result {
Success((target, _)) => {
let bindings = &*target.bindings;
match *bindings.type_def.borrow() {
Some(ref type_def) => {
match type_def.module_def {
None => {
debug!("!!! (resolving module in lexical \
scope) module wasn't actually a \
module!");
return Failed;
}
Some(ref module_def) => {
return Success(module_def.clone());
}
}
}
None => {
debug!("!!! (resolving module in lexical scope) module
wasn't actually a module!");
return Failed;
}
}
}
Indeterminate => {
debug!("(resolving module in lexical scope) indeterminate; \
bailing");
return Indeterminate;
}
Failed => {
debug!("(resolving module in lexical scope) failed to \
resolve");
return Failed;
}
}
}
/// Returns the nearest normal module parent of the given module.
fn get_nearest_normal_module_parent(&mut self, module_: Rc<Module>)
-> Option<Rc<Module>> {
let mut module_ = module_;
loop {
match module_.parent_link.clone() {
NoParentLink => return None,
ModuleParentLink(new_module, _) |
BlockParentLink(new_module, _) => {
let new_module = new_module.upgrade().unwrap();
match new_module.kind.get() {
NormalModuleKind => return Some(new_module),
ExternModuleKind |
TraitModuleKind |
ImplModuleKind |
AnonymousModuleKind => module_ = new_module,
}
}
}
}
}
/// Returns the nearest normal module parent of the given module, or the
/// module itself if it is a normal module.
fn get_nearest_normal_module_parent_or_self(&mut self, module_: Rc<Module>)
-> Rc<Module> {
match module_.kind.get() {
NormalModuleKind => return module_,
ExternModuleKind |
TraitModuleKind |
ImplModuleKind |
AnonymousModuleKind => {
match self.get_nearest_normal_module_parent(module_.clone()) {
None => module_,
Some(new_module) => new_module
}
}
}
}
/// Resolves a "module prefix". A module prefix is one or both of (a) `self::`;
/// (b) some chain of `super::`.
/// grammar: (SELF MOD_SEP ) ? (SUPER MOD_SEP) *
fn resolve_module_prefix(&mut self,
module_: Rc<Module>,
module_path: &[Ident])
-> ResolveResult<ModulePrefixResult> {
// Start at the current module if we see `self` or `super`, or at the
// top of the crate otherwise.
let mut containing_module;
let mut i;
let first_module_path_string = token::get_ident(module_path[0]);
if "self" == first_module_path_string.get() {
containing_module =
self.get_nearest_normal_module_parent_or_self(module_);
i = 1;
} else if "super" == first_module_path_string.get() {
containing_module =
self.get_nearest_normal_module_parent_or_self(module_);
i = 0; // We'll handle `super` below.
} else {
return Success(NoPrefixFound);
}
// Now loop through all the `super`s we find.
while i < module_path.len() {
let string = token::get_ident(module_path[i]);
if "super" != string.get() {
break
}
debug!("(resolving module prefix) resolving `super` at {}",
self.module_to_str(&*containing_module));
match self.get_nearest_normal_module_parent(containing_module) {
None => return Failed,
Some(new_module) => {
containing_module = new_module;
i += 1;
}
}
}
debug!("(resolving module prefix) finished resolving prefix at {}",
self.module_to_str(&*containing_module));
return Success(PrefixFound(containing_module, i));
}
/// Attempts to resolve the supplied name in the given module for the
/// given namespace. If successful, returns the target corresponding to
/// the name.
///
/// The boolean returned on success is an indicator of whether this lookup
/// passed through a public re-export proxy.
fn resolve_name_in_module(&mut self,
module_: Rc<Module>,
name: Name,
namespace: Namespace,
name_search_type: NameSearchType,
allow_private_imports: bool)
-> ResolveResult<(Target, bool)> {
debug!("(resolving name in module) resolving `{}` in `{}`",
token::get_name(name).get(),
self.module_to_str(&*module_));
// First, check the direct children of the module.
self.populate_module_if_necessary(&module_);
match module_.children.borrow().find(&name) {
Some(name_bindings)
if name_bindings.defined_in_namespace(namespace) => {
debug!("(resolving name in module) found node as child");
return Success((Target::new(module_.clone(), name_bindings.clone()),
false));
}
Some(_) | None => {
// Continue.
}
}
// Next, check the module's imports if necessary.
// If this is a search of all imports, we should be done with glob
// resolution at this point.
if name_search_type == PathSearch {
assert_eq!(module_.glob_count.get(), 0);
}
// Check the list of resolved imports.
match module_.import_resolutions.borrow().find(&name) {
Some(import_resolution) if allow_private_imports ||
import_resolution.is_public => {
if import_resolution.is_public &&
import_resolution.outstanding_references != 0 {
debug!("(resolving name in module) import \
unresolved; bailing out");
return Indeterminate;
}
match import_resolution.target_for_namespace(namespace) {
None => {
debug!("(resolving name in module) name found, \
but not in namespace {:?}",
namespace);
}
Some(target) => {
debug!("(resolving name in module) resolved to \
import");
self.used_imports.insert((import_resolution.id(namespace), namespace));
return Success((target, true));
}
}
}
Some(..) | None => {} // Continue.
}
// Finally, search through external children.
if namespace == TypeNS {
match module_.external_module_children.borrow().find_copy(&name) {
None => {}
Some(module) => {
let name_bindings =
Rc::new(Resolver::create_name_bindings_from_module(module));
return Success((Target::new(module_, name_bindings), false));
}
}
}
// We're out of luck.
debug!("(resolving name in module) failed to resolve `{}`",
token::get_name(name).get());
return Failed;
}
fn report_unresolved_imports(&mut self, module_: Rc<Module>) {
let index = module_.resolved_import_count.get();
let imports = module_.imports.borrow();
let import_count = imports.len();
if index != import_count {
let sn = self.session
.codemap()
.span_to_snippet(imports.get(index).span)
.unwrap();
if sn.as_slice().contains("::") {
self.resolve_error(imports.get(index).span,
"unresolved import");
} else {
let err = format!("unresolved import (maybe you meant `{}::*`?)",
sn.as_slice().slice(0, sn.len()));
self.resolve_error(imports.get(index).span, err.as_slice());
}
}
// Descend into children and anonymous children.
self.populate_module_if_necessary(&module_);
for (_, child_node) in module_.children.borrow().iter() {
match child_node.get_module_if_available() {
None => {
// Continue.
}
Some(child_module) => {
self.report_unresolved_imports(child_module);
}
}
}
for (_, module_) in module_.anonymous_children.borrow().iter() {
self.report_unresolved_imports(module_.clone());
}
}
// Export recording
//
// This pass simply determines what all "export" keywords refer to and
// writes the results into the export map.
//
// FIXME #4953 This pass will be removed once exports change to per-item.
// Then this operation can simply be performed as part of item (or import)
// processing.
fn record_exports(&mut self) {
let root_module = self.graph_root.get_module();
self.record_exports_for_module_subtree(root_module);
}
fn record_exports_for_module_subtree(&mut self,
module_: Rc<Module>) {
// If this isn't a local krate, then bail out. We don't need to record
// exports for nonlocal crates.
match module_.def_id.get() {
Some(def_id) if def_id.krate == LOCAL_CRATE => {
// OK. Continue.
debug!("(recording exports for module subtree) recording \
exports for local module `{}`",
self.module_to_str(&*module_));
}
None => {
// Record exports for the root module.
debug!("(recording exports for module subtree) recording \
exports for root module `{}`",
self.module_to_str(&*module_));
}
Some(_) => {
// Bail out.
debug!("(recording exports for module subtree) not recording \
exports for `{}`",
self.module_to_str(&*module_));
return;
}
}
self.record_exports_for_module(&*module_);
self.populate_module_if_necessary(&module_);
for (_, child_name_bindings) in module_.children.borrow().iter() {
match child_name_bindings.get_module_if_available() {
None => {
// Nothing to do.
}
Some(child_module) => {
self.record_exports_for_module_subtree(child_module);
}
}
}
for (_, child_module) in module_.anonymous_children.borrow().iter() {
self.record_exports_for_module_subtree(child_module.clone());
}
}
fn record_exports_for_module(&mut self, module_: &Module) {
let mut exports2 = Vec::new();
self.add_exports_for_module(&mut exports2, module_);
match module_.def_id.get() {
Some(def_id) => {
self.export_map2.borrow_mut().insert(def_id.node, exports2);
debug!("(computing exports) writing exports for {} (some)",
def_id.node);
}
None => {}
}
}
fn add_exports_of_namebindings(&mut self,
exports2: &mut Vec<Export2> ,
name: Name,
namebindings: &NameBindings,
ns: Namespace) {
match namebindings.def_for_namespace(ns) {
Some(d) => {
let name = token::get_name(name);
debug!("(computing exports) YES: export '{}' => {:?}",
name, def_id_of_def(d));
exports2.push(Export2 {
name: name.get().to_strbuf(),
def_id: def_id_of_def(d)
});
}
d_opt => {
debug!("(computing exports) NO: {:?}", d_opt);
}
}
}
fn add_exports_for_module(&mut self,
exports2: &mut Vec<Export2> ,
module_: &Module) {
for (name, importresolution) in module_.import_resolutions.borrow().iter() {
if !importresolution.is_public {
continue
}
let xs = [TypeNS, ValueNS];
for &ns in xs.iter() {
match importresolution.target_for_namespace(ns) {
Some(target) => {
debug!("(computing exports) maybe export '{}'",
token::get_name(*name));
self.add_exports_of_namebindings(exports2,
*name,
&*target.bindings,
ns)
}
_ => ()
}
}
}
}
// AST resolution
//
// We maintain a list of value ribs and type ribs.
//
// Simultaneously, we keep track of the current position in the module
// graph in the `current_module` pointer. When we go to resolve a name in
// the value or type namespaces, we first look through all the ribs and
// then query the module graph. When we resolve a name in the module
// namespace, we can skip all the ribs (since nested modules are not
// allowed within blocks in Rust) and jump straight to the current module
// graph node.
//
// Named implementations are handled separately. When we find a method
// call, we consult the module node to find all of the implementations in
// scope. This information is lazily cached in the module node. We then
// generate a fake "implementation scope" containing all the
// implementations thus found, for compatibility with old resolve pass.
fn with_scope(&mut self, name: Option<Ident>, f: |&mut Resolver|) {
let orig_module = self.current_module.clone();
// Move down in the graph.
match name {
None => {
// Nothing to do.
}
Some(name) => {
self.populate_module_if_necessary(&orig_module);
match orig_module.children.borrow().find(&name.name) {
None => {
debug!("!!! (with scope) didn't find `{}` in `{}`",
token::get_ident(name),
self.module_to_str(&*orig_module));
}
Some(name_bindings) => {
match (*name_bindings).get_module_if_available() {
None => {
debug!("!!! (with scope) didn't find module \
for `{}` in `{}`",
token::get_ident(name),
self.module_to_str(&*orig_module));
}
Some(module_) => {
self.current_module = module_;
}
}
}
}
}
}
f(self);
self.current_module = orig_module;
}
/// Wraps the given definition in the appropriate number of `def_upvar`
/// wrappers.
fn upvarify(&self,
ribs: &[Rib],
rib_index: uint,
def_like: DefLike,
span: Span)
-> Option<DefLike> {
let mut def;
let is_ty_param;
match def_like {
DlDef(d @ DefLocal(..)) | DlDef(d @ DefUpvar(..)) |
DlDef(d @ DefArg(..)) | DlDef(d @ DefBinding(..)) => {
def = d;
is_ty_param = false;
}
DlDef(d @ DefTyParam(..)) => {
def = d;
is_ty_param = true;
}
_ => {
return Some(def_like);
}
}
let mut rib_index = rib_index + 1;
while rib_index < ribs.len() {
match ribs[rib_index].kind {
NormalRibKind => {
// Nothing to do. Continue.
}
FunctionRibKind(function_id, body_id) => {
if !is_ty_param {
def = DefUpvar(def_id_of_def(def).node,
@def,
function_id,
body_id);
}
}
MethodRibKind(item_id, _) => {
// If the def is a ty param, and came from the parent
// item, it's ok
match def {
DefTyParam(did, _) if {
self.def_map.borrow().find(&did.node).map(|x| *x)
== Some(DefTyParamBinder(item_id))
} => {
// ok
}
_ => {
if !is_ty_param {
// This was an attempt to access an upvar inside a
// named function item. This is not allowed, so we
// report an error.
self.resolve_error(
span,
"can't capture dynamic environment in a fn item; \
use the || { ... } closure form instead");
} else {
// This was an attempt to use a type parameter outside
// its scope.
self.resolve_error(span,
"can't use type parameters from \
outer function; try using a local \
type parameter instead");
}
return None;
}
}
}
OpaqueFunctionRibKind => {
if !is_ty_param {
// This was an attempt to access an upvar inside a
// named function item. This is not allowed, so we
// report an error.
self.resolve_error(
span,
"can't capture dynamic environment in a fn item; \
use the || { ... } closure form instead");
} else {
// This was an attempt to use a type parameter outside
// its scope.
self.resolve_error(span,
"can't use type parameters from \
outer function; try using a local \
type parameter instead");
}
return None;
}
ConstantItemRibKind => {
if is_ty_param {
// see #9186
self.resolve_error(span,
"cannot use an outer type \
parameter in this context");
} else {
// Still doesn't deal with upvars
self.resolve_error(span,
"attempt to use a non-constant \
value in a constant");
}
}
}
rib_index += 1;
}
return Some(DlDef(def));
}
fn search_ribs(&self,
ribs: &[Rib],
name: Name,
span: Span)
-> Option<DefLike> {
// FIXME #4950: This should not use a while loop.
// FIXME #4950: Try caching?
let mut i = ribs.len();
while i != 0 {
i -= 1;
let binding_opt = ribs[i].bindings.borrow().find_copy(&name);
match binding_opt {
Some(def_like) => {
return self.upvarify(ribs, i, def_like, span);
}
None => {
// Continue.
}
}
}
return None;
}
fn resolve_crate(&mut self, krate: &ast::Crate) {
debug!("(resolving crate) starting");
visit::walk_crate(self, krate, ());
}
fn resolve_item(&mut self, item: &Item) {
debug!("(resolving item) resolving {}",
token::get_ident(item.ident));
match item.node {
// enum item: resolve all the variants' discrs,
// then resolve the ty params
ItemEnum(ref enum_def, ref generics) => {
for variant in (*enum_def).variants.iter() {
for dis_expr in variant.node.disr_expr.iter() {
// resolve the discriminator expr
// as a constant
self.with_constant_rib(|this| {
this.resolve_expr(*dis_expr);
});
}
}
// n.b. the discr expr gets visited twice.
// but maybe it's okay since the first time will signal an
// error if there is one? -- tjc
self.with_type_parameter_rib(HasTypeParameters(generics,
item.id,
0,
NormalRibKind),
|this| {
visit::walk_item(this, item, ());
});
}
ItemTy(_, ref generics) => {
self.with_type_parameter_rib(HasTypeParameters(generics,
item.id,
0,
NormalRibKind),
|this| {
visit::walk_item(this, item, ());
});
}
ItemImpl(ref generics,
ref implemented_traits,
self_type,
ref methods) => {
self.resolve_implementation(item.id,
generics,
implemented_traits,
self_type,
methods.as_slice());
}
ItemTrait(ref generics, _, ref traits, ref methods) => {
// Create a new rib for the self type.
let self_type_rib = Rib::new(NormalRibKind);
// plain insert (no renaming)
let name = self.type_self_ident.name;
self_type_rib.bindings.borrow_mut()
.insert(name, DlDef(DefSelfTy(item.id)));
self.type_ribs.borrow_mut().push(self_type_rib);
// Create a new rib for the trait-wide type parameters.
self.with_type_parameter_rib(HasTypeParameters(generics,
item.id,
0,
NormalRibKind),
|this| {
this.resolve_type_parameters(&generics.ty_params);
// Resolve derived traits.
for trt in traits.iter() {
this.resolve_trait_reference(item.id, trt, TraitDerivation);
}
for method in (*methods).iter() {
// Create a new rib for the method-specific type
// parameters.
//
// FIXME #4951: Do we need a node ID here?
match *method {
ast::Required(ref ty_m) => {
this.with_type_parameter_rib
(HasTypeParameters(&ty_m.generics,
item.id,
generics.ty_params.len(),
MethodRibKind(item.id, Required)),
|this| {
// Resolve the method-specific type
// parameters.
this.resolve_type_parameters(
&ty_m.generics.ty_params);
for argument in ty_m.decl.inputs.iter() {
this.resolve_type(argument.ty);
}
this.resolve_type(ty_m.decl.output);
});
}
ast::Provided(m) => {
this.resolve_method(MethodRibKind(item.id,
Provided(m.id)),
m,
generics.ty_params.len())
}
}
}
});
self.type_ribs.borrow_mut().pop();
}
ItemStruct(ref struct_def, ref generics) => {
self.resolve_struct(item.id,
generics,
struct_def.super_struct,
struct_def.fields.as_slice());
}
ItemMod(ref module_) => {
self.with_scope(Some(item.ident), |this| {
this.resolve_module(module_, item.span, item.ident,
item.id);
});
}
ItemForeignMod(ref foreign_module) => {
self.with_scope(Some(item.ident), |this| {
for foreign_item in foreign_module.items.iter() {
match foreign_item.node {
ForeignItemFn(_, ref generics) => {
this.with_type_parameter_rib(
HasTypeParameters(
generics, foreign_item.id, 0,
NormalRibKind),
|this| visit::walk_foreign_item(this,
*foreign_item,
()));
}
ForeignItemStatic(..) => {
visit::walk_foreign_item(this,
*foreign_item,
());
}
}
}
});
}
ItemFn(fn_decl, _, _, ref generics, block) => {
self.resolve_function(OpaqueFunctionRibKind,
Some(fn_decl),
HasTypeParameters
(generics,
item.id,
0,
OpaqueFunctionRibKind),
block);
}
ItemStatic(..) => {
self.with_constant_rib(|this| {
visit::walk_item(this, item, ());
});
}
ItemMac(..) => {
// do nothing, these are just around to be encoded
}
}
}
fn with_type_parameter_rib(&mut self,
type_parameters: TypeParameters,
f: |&mut Resolver|) {
match type_parameters {
HasTypeParameters(generics, node_id, initial_index,
rib_kind) => {
let function_type_rib = Rib::new(rib_kind);
for (index, type_parameter) in generics.ty_params.iter().enumerate() {
let ident = type_parameter.ident;
debug!("with_type_parameter_rib: {} {}", node_id,
type_parameter.id);
let def_like = DlDef(DefTyParam
(local_def(type_parameter.id),
index + initial_index));
// Associate this type parameter with
// the item that bound it
self.record_def(type_parameter.id,
(DefTyParamBinder(node_id), LastMod(AllPublic)));
// plain insert (no renaming)
function_type_rib.bindings.borrow_mut()
.insert(ident.name, def_like);
}
self.type_ribs.borrow_mut().push(function_type_rib);
}
NoTypeParameters => {
// Nothing to do.
}
}
f(self);
match type_parameters {
HasTypeParameters(..) => { self.type_ribs.borrow_mut().pop(); }
NoTypeParameters => { }
}
}
fn with_label_rib(&mut self, f: |&mut Resolver|) {
self.label_ribs.borrow_mut().push(Rib::new(NormalRibKind));
f(self);
self.label_ribs.borrow_mut().pop();
}
fn with_constant_rib(&mut self, f: |&mut Resolver|) {
self.value_ribs.borrow_mut().push(Rib::new(ConstantItemRibKind));
self.type_ribs.borrow_mut().push(Rib::new(ConstantItemRibKind));
f(self);
self.type_ribs.borrow_mut().pop();
self.value_ribs.borrow_mut().pop();
}
fn resolve_function(&mut self,
rib_kind: RibKind,
optional_declaration: Option<P<FnDecl>>,
type_parameters: TypeParameters,
block: P<Block>) {
// Create a value rib for the function.
let function_value_rib = Rib::new(rib_kind);
self.value_ribs.borrow_mut().push(function_value_rib);
// Create a label rib for the function.
let function_label_rib = Rib::new(rib_kind);
self.label_ribs.borrow_mut().push(function_label_rib);
// If this function has type parameters, add them now.
self.with_type_parameter_rib(type_parameters, |this| {
// Resolve the type parameters.
match type_parameters {
NoTypeParameters => {
// Continue.
}
HasTypeParameters(ref generics, _, _, _) => {
this.resolve_type_parameters(&generics.ty_params);
}
}
// Add each argument to the rib.
match optional_declaration {
None => {
// Nothing to do.
}
Some(declaration) => {
for argument in declaration.inputs.iter() {
this.resolve_pattern(argument.pat,
ArgumentIrrefutableMode,
None);
this.resolve_type(argument.ty);
debug!("(resolving function) recorded argument");
}
this.resolve_type(declaration.output);
}
}
// Resolve the function body.
this.resolve_block(block);
debug!("(resolving function) leaving function");
});
self.label_ribs.borrow_mut().pop();
self.value_ribs.borrow_mut().pop();
}
fn resolve_type_parameters(&mut self,
type_parameters: &OwnedSlice<TyParam>) {
for type_parameter in type_parameters.iter() {
for bound in type_parameter.bounds.iter() {
self.resolve_type_parameter_bound(type_parameter.id, bound);
}
match type_parameter.default {
Some(ty) => self.resolve_type(ty),
None => {}
}
}
}
fn resolve_type_parameter_bound(&mut self,
id: NodeId,
type_parameter_bound: &TyParamBound) {
match *type_parameter_bound {
TraitTyParamBound(ref tref) => {
self.resolve_trait_reference(id, tref, TraitBoundingTypeParameter)
}
StaticRegionTyParamBound => {}
OtherRegionTyParamBound(_) => {}
}
}
fn resolve_trait_reference(&mut self,
id: NodeId,
trait_reference: &TraitRef,
reference_type: TraitReferenceType) {
match self.resolve_path(id, &trait_reference.path, TypeNS, true) {
None => {
let path_str = self.path_idents_to_str(&trait_reference.path);
let usage_str = match reference_type {
TraitBoundingTypeParameter => "bound type parameter with",
TraitImplementation => "implement",
TraitDerivation => "derive"
};
let msg = format!("attempt to {} a nonexistent trait `{}`", usage_str, path_str);
self.resolve_error(trait_reference.path.span, msg.as_slice());
}
Some(def) => {
debug!("(resolving trait) found trait def: {:?}", def);
self.record_def(trait_reference.ref_id, def);
}
}
}
fn resolve_struct(&mut self,
id: NodeId,
generics: &Generics,
super_struct: Option<P<Ty>>,
fields: &[StructField]) {
// If applicable, create a rib for the type parameters.
self.with_type_parameter_rib(HasTypeParameters(generics,
id,
0,
OpaqueFunctionRibKind),
|this| {
// Resolve the type parameters.
this.resolve_type_parameters(&generics.ty_params);
// Resolve the super struct.
match super_struct {
Some(t) => match t.node {
TyPath(ref path, None, path_id) => {
match this.resolve_path(id, path, TypeNS, true) {
Some((DefTy(def_id), lp)) if this.structs.contains_key(&def_id) => {
let def = DefStruct(def_id);
debug!("(resolving struct) resolved `{}` to type {:?}",
token::get_ident(path.segments
.last().unwrap()
.identifier),
def);
debug!("(resolving struct) writing resolution for `{}` (id {})",
this.path_idents_to_str(path),
path_id);
this.record_def(path_id, (def, lp));
}
Some((DefStruct(_), _)) => {
this.session.span_err(t.span,
"super-struct is defined \
in a different crate")
},
Some(_) => this.session.span_err(t.span,
"super-struct is not a struct type"),
None => this.session.span_err(t.span,
"super-struct could not be resolved"),
}
},
_ => this.session.span_bug(t.span, "path not mapped to a TyPath")
},
None => {}
}
// Resolve fields.
for field in fields.iter() {
this.resolve_type(field.node.ty);
}
});
}
// Does this really need to take a RibKind or is it always going
// to be NormalRibKind?
fn resolve_method(&mut self,
rib_kind: RibKind,
method: &Method,
outer_type_parameter_count: uint) {
let method_generics = &method.generics;
let type_parameters =
HasTypeParameters(method_generics,
method.id,
outer_type_parameter_count,
rib_kind);
self.resolve_function(rib_kind, Some(method.decl), type_parameters, method.body);
}
fn with_current_self_type<T>(&mut self, self_type: &Ty, f: |&mut Resolver| -> T) -> T {
// Handle nested impls (inside fn bodies)
let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
let result = f(self);
self.current_self_type = previous_value;
result
}
fn with_optional_trait_ref<T>(&mut self, id: NodeId,
opt_trait_ref: &Option<TraitRef>,
f: |&mut Resolver| -> T) -> T {
let new_val = match *opt_trait_ref {
Some(ref trait_ref) => {
self.resolve_trait_reference(id, trait_ref, TraitImplementation);
match self.def_map.borrow().find(&trait_ref.ref_id) {
Some(def) => {
let did = def_id_of_def(*def);
Some((did, trait_ref.clone()))
}
None => None
}
}
None => None
};
let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
let result = f(self);
self.current_trait_ref = original_trait_ref;
result
}
fn resolve_implementation(&mut self,
id: NodeId,
generics: &Generics,
opt_trait_reference: &Option<TraitRef>,
self_type: &Ty,
methods: &[@Method]) {
// If applicable, create a rib for the type parameters.
let outer_type_parameter_count = generics.ty_params.len();
self.with_type_parameter_rib(HasTypeParameters(generics,
id,
0,
NormalRibKind),
|this| {
// Resolve the type parameters.
this.resolve_type_parameters(&generics.ty_params);
// Resolve the trait reference, if necessary.
this.with_optional_trait_ref(id, opt_trait_reference, |this| {
// Resolve the self type.
this.resolve_type(self_type);
this.with_current_self_type(self_type, |this| {
for method in methods.iter() {
// We also need a new scope for the method-specific type parameters.
this.resolve_method(MethodRibKind(id, Provided(method.id)),
*method,
outer_type_parameter_count);
}
});
});
});
}
fn resolve_module(&mut self, module: &Mod, _span: Span,
_name: Ident, id: NodeId) {
// Write the implementations in scope into the module metadata.
debug!("(resolving module) resolving module ID {}", id);
visit::walk_mod(self, module, ());
}
fn resolve_local(&mut self, local: &Local) {
// Resolve the type.
self.resolve_type(local.ty);
// Resolve the initializer, if necessary.
match local.init {
None => {
// Nothing to do.
}
Some(initializer) => {
self.resolve_expr(initializer);
}
}
// Resolve the pattern.
self.resolve_pattern(local.pat, LocalIrrefutableMode, None);
}
// build a map from pattern identifiers to binding-info's.
// this is done hygienically. This could arise for a macro
// that expands into an or-pattern where one 'x' was from the
// user and one 'x' came from the macro.
fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
let mut result = HashMap::new();
pat_bindings(&self.def_map, pat, |binding_mode, _id, sp, path| {
let name = mtwt::resolve(path_to_ident(path));
result.insert(name,
binding_info {span: sp,
binding_mode: binding_mode});
});
return result;
}
// check that all of the arms in an or-pattern have exactly the
// same set of bindings, with the same binding modes for each.
fn check_consistent_bindings(&mut self, arm: &Arm) {
if arm.pats.len() == 0 {
return
}
let map_0 = self.binding_mode_map(*arm.pats.get(0));
for (i, p) in arm.pats.iter().enumerate() {
let map_i = self.binding_mode_map(*p);
for (&key, &binding_0) in map_0.iter() {
match map_i.find(&key) {
None => {
self.resolve_error(
p.span,
format!("variable `{}` from pattern \\#1 is \
not bound in pattern \\#{}",
token::get_name(key),
i + 1).as_slice());
}
Some(binding_i) => {
if binding_0.binding_mode != binding_i.binding_mode {
self.resolve_error(
binding_i.span,
format!("variable `{}` is bound with different \
mode in pattern \\#{} than in pattern \\#1",
token::get_name(key),
i + 1).as_slice());
}
}
}
}
for (&key, &binding) in map_i.iter() {
if !map_0.contains_key(&key) {
self.resolve_error(
binding.span,
format!("variable `{}` from pattern \\#{} is \
not bound in pattern \\#1",
token::get_name(key),
i + 1).as_slice());
}
}
}
}
fn resolve_arm(&mut self, arm: &Arm) {
self.value_ribs.borrow_mut().push(Rib::new(NormalRibKind));
let mut bindings_list = HashMap::new();
for pattern in arm.pats.iter() {
self.resolve_pattern(*pattern,
RefutableMode,
Some(&mut bindings_list));
}
// This has to happen *after* we determine which
// pat_idents are variants
self.check_consistent_bindings(arm);
visit::walk_expr_opt(self, arm.guard, ());
self.resolve_expr(arm.body);
self.value_ribs.borrow_mut().pop();
}
fn resolve_block(&mut self, block: &Block) {
debug!("(resolving block) entering block");
self.value_ribs.borrow_mut().push(Rib::new(NormalRibKind));
// Move down in the graph, if there's an anonymous module rooted here.
let orig_module = self.current_module.clone();
match orig_module.anonymous_children.borrow().find(&block.id) {
None => { /* Nothing to do. */ }
Some(anonymous_module) => {
debug!("(resolving block) found anonymous module, moving \
down");
self.current_module = anonymous_module.clone();
}
}
// Descend into the block.
visit::walk_block(self, block, ());
// Move back up.
self.current_module = orig_module;
self.value_ribs.borrow_mut().pop();
debug!("(resolving block) leaving block");
}
fn resolve_type(&mut self, ty: &Ty) {
match ty.node {
// Like path expressions, the interpretation of path types depends
// on whether the path has multiple elements in it or not.
TyPath(ref path, ref bounds, path_id) => {
// This is a path in the type namespace. Walk through scopes
// looking for it.
let mut result_def = None;
// First, check to see whether the name is a primitive type.
if path.segments.len() == 1 {
let id = path.segments.last().unwrap().identifier;
match self.primitive_type_table
.primitive_types
.find(&id.name) {
Some(&primitive_type) => {
result_def =
Some((DefPrimTy(primitive_type), LastMod(AllPublic)));
if path.segments
.iter()
.any(|s| !s.lifetimes.is_empty()) {
self.session.span_err(path.span,
"lifetime parameters \
are not allowed on \
this type")
} else if path.segments
.iter()
.any(|s| s.types.len() > 0) {
self.session.span_err(path.span,
"type parameters are \
not allowed on this \
type")
}
}
None => {
// Continue.
}
}
}
match result_def {
None => {
match self.resolve_path(ty.id, path, TypeNS, true) {
Some(def) => {
debug!("(resolving type) resolved `{}` to \
type {:?}",
token::get_ident(path.segments
.last().unwrap()
.identifier),
def);
result_def = Some(def);
}
None => {
result_def = None;
}
}
}
Some(_) => {} // Continue.
}
match result_def {
Some(def) => {
// Write the result into the def map.
debug!("(resolving type) writing resolution for `{}` \
(id {})",
self.path_idents_to_str(path),
path_id);
self.record_def(path_id, def);
}
None => {
let msg = format!("use of undeclared type name `{}`",
self.path_idents_to_str(path));
self.resolve_error(ty.span, msg.as_slice());
}
}
bounds.as_ref().map(|bound_vec| {
for bound in bound_vec.iter() {
self.resolve_type_parameter_bound(ty.id, bound);
}
});
}
TyClosure(c, _) | TyProc(c) => {
c.bounds.as_ref().map(|bounds| {
for bound in bounds.iter() {
self.resolve_type_parameter_bound(ty.id, bound);
}
});
visit::walk_ty(self, ty, ());
}
_ => {
// Just resolve embedded types.
visit::walk_ty(self, ty, ());
}
}
}
fn resolve_pattern(&mut self,
pattern: &Pat,
mode: PatternBindingMode,
// Maps idents to the node ID for the (outermost)
// pattern that binds them
mut bindings_list: Option<&mut HashMap<Name,NodeId>>) {
let pat_id = pattern.id;
walk_pat(pattern, |pattern| {
match pattern.node {
PatIdent(binding_mode, ref path, _)
if !path.global && path.segments.len() == 1 => {
// The meaning of pat_ident with no type parameters
// depends on whether an enum variant or unit-like struct
// with that name is in scope. The probing lookup has to
// be careful not to emit spurious errors. Only matching
// patterns (match) can match nullary variants or
// unit-like structs. For binding patterns (let), matching
// such a value is simply disallowed (since it's rarely
// what you want).
let ident = path.segments.get(0).identifier;
let renamed = mtwt::resolve(ident);
match self.resolve_bare_identifier_pattern(ident) {
FoundStructOrEnumVariant(def, lp)
if mode == RefutableMode => {
debug!("(resolving pattern) resolving `{}` to \
struct or enum variant",
token::get_name(renamed));
self.enforce_default_binding_mode(
pattern,
binding_mode,
"an enum variant");
self.record_def(pattern.id, (def, lp));
}
FoundStructOrEnumVariant(..) => {
self.resolve_error(
pattern.span,
format!("declaration of `{}` shadows an enum \
variant or unit-like struct in \
scope",
token::get_name(renamed)).as_slice());
}
FoundConst(def, lp) if mode == RefutableMode => {
debug!("(resolving pattern) resolving `{}` to \
constant",
token::get_name(renamed));
self.enforce_default_binding_mode(
pattern,
binding_mode,
"a constant");
self.record_def(pattern.id, (def, lp));
}
FoundConst(..) => {
self.resolve_error(pattern.span,
"only irrefutable patterns \
allowed here");
}
BareIdentifierPatternUnresolved => {
debug!("(resolving pattern) binding `{}`",
token::get_name(renamed));
let def = match mode {
RefutableMode => {
// For pattern arms, we must use
// `def_binding` definitions.
DefBinding(pattern.id, binding_mode)
}
LocalIrrefutableMode => {
// But for locals, we use `def_local`.
DefLocal(pattern.id, binding_mode)
}
ArgumentIrrefutableMode => {
// And for function arguments, `def_arg`.
DefArg(pattern.id, binding_mode)
}
};
// Record the definition so that later passes
// will be able to distinguish variants from
// locals in patterns.
self.record_def(pattern.id, (def, LastMod(AllPublic)));
// Add the binding to the local ribs, if it
// doesn't already exist in the bindings list. (We
// must not add it if it's in the bindings list
// because that breaks the assumptions later
// passes make about or-patterns.)
match bindings_list {
Some(ref mut bindings_list)
if !bindings_list.contains_key(&renamed) => {
let this = &mut *self;
let value_ribs = this.value_ribs.borrow();
let length = value_ribs.len();
let last_rib = value_ribs.get(
length - 1);
last_rib.bindings.borrow_mut()
.insert(renamed, DlDef(def));
bindings_list.insert(renamed, pat_id);
}
Some(ref mut b) => {
if b.find(&renamed) == Some(&pat_id) {
// Then this is a duplicate variable
// in the same disjunct, which is an
// error
self.resolve_error(pattern.span,
format!("identifier `{}` is bound \
more than once in the same \
pattern",
path_to_str(path)).as_slice());
}
// Not bound in the same pattern: do nothing
}
None => {
let this = &mut *self;
{
let value_ribs = this.value_ribs.borrow();
let length = value_ribs.len();
let last_rib = value_ribs.get(
length - 1);
last_rib.bindings.borrow_mut()
.insert(renamed, DlDef(def));
}
}
}
}
}
// Check the types in the path pattern.
for &ty in path.segments
.iter()
.flat_map(|seg| seg.types.iter()) {
self.resolve_type(ty);
}
}
PatIdent(binding_mode, ref path, _) => {
// This must be an enum variant, struct, or constant.
match self.resolve_path(pat_id, path, ValueNS, false) {
Some(def @ (DefVariant(..), _)) |
Some(def @ (DefStruct(..), _)) => {
self.record_def(pattern.id, def);
}
Some(def @ (DefStatic(..), _)) => {
self.enforce_default_binding_mode(
pattern,
binding_mode,
"a constant");
self.record_def(pattern.id, def);
}
Some(_) => {
self.resolve_error(
path.span,
format!("`{}` is not an enum variant or constant",
token::get_ident(
path.segments
.last()
.unwrap()
.identifier)).as_slice())
}
None => {
self.resolve_error(path.span,
"unresolved enum variant");
}
}
// Check the types in the path pattern.
for &ty in path.segments
.iter()
.flat_map(|s| s.types.iter()) {
self.resolve_type(ty);
}
}
PatEnum(ref path, _) => {
// This must be an enum variant, struct or const.
match self.resolve_path(pat_id, path, ValueNS, false) {
Some(def @ (DefFn(..), _)) |
Some(def @ (DefVariant(..), _)) |
Some(def @ (DefStruct(..), _)) |
Some(def @ (DefStatic(..), _)) => {
self.record_def(pattern.id, def);
}
Some(_) => {
self.resolve_error(path.span,
format!("`{}` is not an enum variant, struct or const",
token::get_ident(
path.segments
.last()
.unwrap()
.identifier)).as_slice());
}
None => {
self.resolve_error(path.span,
format!("unresolved enum variant, struct or const `{}`",
token::get_ident(
path.segments
.last()
.unwrap()
.identifier)).as_slice());
}
}
// Check the types in the path pattern.
for &ty in path.segments
.iter()
.flat_map(|s| s.types.iter()) {
self.resolve_type(ty);
}
}
PatLit(expr) => {
self.resolve_expr(expr);
}
PatRange(first_expr, last_expr) => {
self.resolve_expr(first_expr);
self.resolve_expr(last_expr);
}
PatStruct(ref path, _, _) => {
match self.resolve_path(pat_id, path, TypeNS, false) {
Some((DefTy(class_id), lp))
if self.structs.contains_key(&class_id) => {
let class_def = DefStruct(class_id);
self.record_def(pattern.id, (class_def, lp));
}
Some(definition @ (DefStruct(class_id), _)) => {
assert!(self.structs.contains_key(&class_id));
self.record_def(pattern.id, definition);
}
Some(definition @ (DefVariant(_, variant_id, _), _))
if self.structs.contains_key(&variant_id) => {
self.record_def(pattern.id, definition);
}
result => {
debug!("(resolving pattern) didn't find struct \
def: {:?}", result);
let msg = format!("`{}` does not name a structure",
self.path_idents_to_str(path));
self.resolve_error(path.span, msg.as_slice());
}
}
}
_ => {
// Nothing to do.
}
}
true
});
}
fn resolve_bare_identifier_pattern(&mut self, name: Ident)
-> BareIdentifierPatternResolution {
let module = self.current_module.clone();
match self.resolve_item_in_lexical_scope(module,
name,
ValueNS) {
Success((target, _)) => {
debug!("(resolve bare identifier pattern) succeeded in \
finding {} at {:?}",
token::get_ident(name),
target.bindings.value_def.borrow());
match *target.bindings.value_def.borrow() {
None => {
fail!("resolved name in the value namespace to a \
set of name bindings with no def?!");
}
Some(def) => {
// For the two success cases, this lookup can be
// considered as not having a private component because
// the lookup happened only within the current module.
match def.def {
def @ DefVariant(..) | def @ DefStruct(..) => {
return FoundStructOrEnumVariant(def, LastMod(AllPublic));
}
def @ DefStatic(_, false) => {
return FoundConst(def, LastMod(AllPublic));
}
_ => {
return BareIdentifierPatternUnresolved;
}
}
}
}
}
Indeterminate => {
fail!("unexpected indeterminate result");
}
Failed => {
debug!("(resolve bare identifier pattern) failed to find {}",
token::get_ident(name));
return BareIdentifierPatternUnresolved;
}
}
}
/// If `check_ribs` is true, checks the local definitions first; i.e.
/// doesn't skip straight to the containing module.
fn resolve_path(&mut self,
id: NodeId,
path: &Path,
namespace: Namespace,
check_ribs: bool) -> Option<(Def, LastPrivate)> {
// First, resolve the types.
for &ty in path.segments.iter().flat_map(|s| s.types.iter()) {
self.resolve_type(ty);
}
if path.global {
return self.resolve_crate_relative_path(path, namespace);
}
let unqualified_def =
self.resolve_identifier(path.segments
.last().unwrap()
.identifier,
namespace,
check_ribs,
path.span);
if path.segments.len() > 1 {
let def = self.resolve_module_relative_path(path, namespace);
match (def, unqualified_def) {
(Some((d, _)), Some((ud, _))) if d == ud => {
self.session
.add_lint(UnnecessaryQualification,
id,
path.span,
"unnecessary qualification".to_strbuf());
}
_ => ()
}
return def;
}
return unqualified_def;
}
// resolve a single identifier (used as a varref)
fn resolve_identifier(&mut self,
identifier: Ident,
namespace: Namespace,
check_ribs: bool,
span: Span)
-> Option<(Def, LastPrivate)> {
if check_ribs {
match self.resolve_identifier_in_local_ribs(identifier,
namespace,
span) {
Some(def) => {
return Some((def, LastMod(AllPublic)));
}
None => {
// Continue.
}
}
}
return self.resolve_item_by_identifier_in_lexical_scope(identifier,
namespace);
}
// FIXME #4952: Merge me with resolve_name_in_module?
fn resolve_definition_of_name_in_module(&mut self,
containing_module: Rc<Module>,
name: Name,
namespace: Namespace)
-> NameDefinition {
// First, search children.
self.populate_module_if_necessary(&containing_module);
match containing_module.children.borrow().find(&name) {
Some(child_name_bindings) => {
match child_name_bindings.def_for_namespace(namespace) {
Some(def) => {
// Found it. Stop the search here.
let p = child_name_bindings.defined_in_public_namespace(
namespace);
let lp = if p {LastMod(AllPublic)} else {
LastMod(DependsOn(def_id_of_def(def)))
};
return ChildNameDefinition(def, lp);
}
None => {}
}
}
None => {}
}
// Next, search import resolutions.
match containing_module.import_resolutions.borrow().find(&name) {
Some(import_resolution) if import_resolution.is_public => {
match (*import_resolution).target_for_namespace(namespace) {
Some(target) => {
match target.bindings.def_for_namespace(namespace) {
Some(def) => {
// Found it.
let id = import_resolution.id(namespace);
self.used_imports.insert((id, namespace));
return ImportNameDefinition(def, LastMod(AllPublic));
}
None => {
// This can happen with external impls, due to
// the imperfect way we read the metadata.
}
}
}
None => {}
}
}
Some(..) | None => {} // Continue.
}
// Finally, search through external children.
if namespace == TypeNS {
match containing_module.external_module_children.borrow()
.find_copy(&name) {
None => {}
Some(module) => {
match module.def_id.get() {
None => {} // Continue.
Some(def_id) => {
let lp = if module.is_public {LastMod(AllPublic)} else {
LastMod(DependsOn(def_id))
};
return ChildNameDefinition(DefMod(def_id), lp);
}
}
}
}
}
return NoNameDefinition;
}
// resolve a "module-relative" path, e.g. a::b::c
fn resolve_module_relative_path(&mut self,
path: &Path,
namespace: Namespace)
-> Option<(Def, LastPrivate)> {
let module_path_idents = path.segments.init().iter()
.map(|ps| ps.identifier)
.collect::<Vec<_>>();
let containing_module;
let last_private;
let module = self.current_module.clone();
match self.resolve_module_path(module,
module_path_idents.as_slice(),
UseLexicalScope,
path.span,
PathSearch) {
Failed => {
let msg = format!("use of undeclared module `{}`",
self.idents_to_str(module_path_idents.as_slice()));
self.resolve_error(path.span, msg.as_slice());
return None;
}
Indeterminate => {
fail!("indeterminate unexpected");
}
Success((resulting_module, resulting_last_private)) => {
containing_module = resulting_module;
last_private = resulting_last_private;
}
}
let ident = path.segments.last().unwrap().identifier;
let def = match self.resolve_definition_of_name_in_module(containing_module.clone(),
ident.name,
namespace) {
NoNameDefinition => {
// We failed to resolve the name. Report an error.
return None;
}
ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
(def, last_private.or(lp))
}
};
match containing_module.kind.get() {
TraitModuleKind | ImplModuleKind => {
match containing_module.def_id.get() {
Some(def_id) => {
match self.method_map.borrow().find(&(ident.name, def_id)) {
Some(x) if *x == SelfStatic => (),
None => (),
_ => {
debug!("containing module was a trait or impl \
and name was a method -> not resolved");
return None;
}
}
},
_ => (),
}
},
_ => (),
}
return Some(def);
}
/// Invariant: This must be called only during main resolution, not during
/// import resolution.
fn resolve_crate_relative_path(&mut self,
path: &Path,
namespace: Namespace)
-> Option<(Def, LastPrivate)> {
let module_path_idents = path.segments.init().iter()
.map(|ps| ps.identifier)
.collect::<Vec<_>>();
let root_module = self.graph_root.get_module();
let containing_module;
let last_private;
match self.resolve_module_path_from_root(root_module,
module_path_idents.as_slice(),
0,
path.span,
PathSearch,
LastMod(AllPublic)) {
Failed => {
let msg = format!("use of undeclared module `::{}`",
self.idents_to_str(module_path_idents.as_slice()));
self.resolve_error(path.span, msg.as_slice());
return None;
}
Indeterminate => {
fail!("indeterminate unexpected");
}
Success((resulting_module, resulting_last_private)) => {
containing_module = resulting_module;
last_private = resulting_last_private;
}
}
let name = path.segments.last().unwrap().identifier.name;
match self.resolve_definition_of_name_in_module(containing_module,
name,
namespace) {
NoNameDefinition => {
// We failed to resolve the name. Report an error.
return None;
}
ChildNameDefinition(def, lp) | ImportNameDefinition(def, lp) => {
return Some((def, last_private.or(lp)));
}
}
}
fn resolve_identifier_in_local_ribs(&mut self,
ident: Ident,
namespace: Namespace,
span: Span)
-> Option<Def> {
// Check the local set of ribs.
let search_result = match namespace {
ValueNS => {
let renamed = mtwt::resolve(ident);
self.search_ribs(self.value_ribs.borrow().as_slice(),
renamed, span)
}
TypeNS => {
let name = ident.name;
self.search_ribs(self.type_ribs.borrow().as_slice(), name, span)
}
};
match search_result {
Some(DlDef(def)) => {
debug!("(resolving path in local ribs) resolved `{}` to \
local: {:?}",
token::get_ident(ident),
def);
return Some(def);
}
Some(DlField) | Some(DlImpl(_)) | None => {
return None;
}
}
}
fn resolve_item_by_identifier_in_lexical_scope(&mut self,
ident: Ident,
namespace: Namespace)
-> Option<(Def, LastPrivate)> {
// Check the items.
let module = self.current_module.clone();
match self.resolve_item_in_lexical_scope(module,
ident,
namespace) {
Success((target, _)) => {
match (*target.bindings).def_for_namespace(namespace) {
None => {
// This can happen if we were looking for a type and
// found a module instead. Modules don't have defs.
debug!("(resolving item path by identifier in lexical \
scope) failed to resolve {} after success...",
token::get_ident(ident));
return None;
}
Some(def) => {
debug!("(resolving item path in lexical scope) \
resolved `{}` to item",
token::get_ident(ident));
// This lookup is "all public" because it only searched
// for one identifier in the current module (couldn't
// have passed through reexports or anything like that.
return Some((def, LastMod(AllPublic)));
}
}
}
Indeterminate => {
fail!("unexpected indeterminate result");
}
Failed => {
debug!("(resolving item path by identifier in lexical scope) \
failed to resolve {}", token::get_ident(ident));
return None;
}
}
}
fn with_no_errors<T>(&mut self, f: |&mut Resolver| -> T) -> T {
self.emit_errors = false;
let rs = f(self);
self.emit_errors = true;
rs
}
fn resolve_error(&self, span: Span, s: &str) {
if self.emit_errors {
self.session.span_err(span, s);
}
}
fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
#[deriving(Eq)]
enum FallbackChecks {
Everything,
OnlyTraitAndStatics
}
fn extract_path_and_node_id(t: &Ty, allow: FallbackChecks)
-> Option<(Path, NodeId, FallbackChecks)> {
match t.node {
TyPath(ref path, _, node_id) => Some((path.clone(), node_id, allow)),
TyPtr(mut_ty) => extract_path_and_node_id(mut_ty.ty, OnlyTraitAndStatics),
TyRptr(_, mut_ty) => extract_path_and_node_id(mut_ty.ty, allow),
// This doesn't handle the remaining `Ty` variants as they are not
// that commonly the self_type, it might be interesting to provide
// support for those in future.
_ => None,
}
}
fn get_module(this: &mut Resolver, span: Span, ident_path: &[ast::Ident])
-> Option<Rc<Module>> {
let root = this.current_module.clone();
let last_name = ident_path.last().unwrap().name;
if ident_path.len() == 1 {
match this.primitive_type_table.primitive_types.find(&last_name) {
Some(_) => None,
None => {
match this.current_module.children.borrow().find(&last_name) {
Some(child) => child.get_module_if_available(),
None => None
}
}
}
} else {
match this.resolve_module_path(root,
ident_path.as_slice(),
UseLexicalScope,
span,
PathSearch) {
Success((module, _)) => Some(module),
_ => None
}
}
}
let (path, node_id, allowed) = match self.current_self_type {
Some(ref ty) => match extract_path_and_node_id(ty, Everything) {
Some(x) => x,
None => return NoSuggestion,
},
None => return NoSuggestion,
};
if allowed == Everything {
// Look for a field with the same name in the current self_type.
match self.def_map.borrow().find(&node_id) {
Some(&DefTy(did))
| Some(&DefStruct(did))
| Some(&DefVariant(_, did, _)) => match self.structs.find(&did) {
None => {}
Some(fields) => {
if fields.iter().any(|&field_name| name == field_name) {
return Field;
}
}
},
_ => {} // Self type didn't resolve properly
}
}
let ident_path = path.segments.iter().map(|seg| seg.identifier).collect::<Vec<_>>();
// Look for a method in the current self type's impl module.
match get_module(self, path.span, ident_path.as_slice()) {
Some(module) => match module.children.borrow().find(&name) {
Some(binding) => {
let p_str = self.path_idents_to_str(&path);
match binding.def_for_namespace(ValueNS) {
Some(DefStaticMethod(_, provenance, _)) => {
match provenance {
FromImpl(_) => return StaticMethod(p_str),
FromTrait(_) => unreachable!()
}
}
Some(DefMethod(_, None)) if allowed == Everything => return Method,
Some(DefMethod(_, Some(_))) => return TraitMethod,
_ => ()
}
}
None => {}
},
None => {}
}
// Look for a method in the current trait.
let method_map = self.method_map.borrow();
match self.current_trait_ref {
Some((did, ref trait_ref)) => {
let path_str = self.path_idents_to_str(&trait_ref.path);
match method_map.find(&(name, did)) {
Some(&SelfStatic) => return StaticTraitMethod(path_str),
Some(_) => return TraitMethod,
None => {}
}
}
None => {}
}
NoSuggestion
}
fn find_best_match_for_name(&mut self, name: &str, max_distance: uint)
-> Option<StrBuf> {
let this = &mut *self;
let mut maybes: Vec<token::InternedString> = Vec::new();
let mut values: Vec<uint> = Vec::new();
let mut j = this.value_ribs.borrow().len();
while j != 0 {
j -= 1;
let value_ribs = this.value_ribs.borrow();
let bindings = value_ribs.get(j).bindings.borrow();
for (&k, _) in bindings.iter() {
maybes.push(token::get_name(k));
values.push(uint::MAX);
}
}
let mut smallest = 0;
for (i, other) in maybes.iter().enumerate() {
*values.get_mut(i) = name.lev_distance(other.get());
if *values.get(i) <= *values.get(smallest) {
smallest = i;
}
}
if values.len() > 0 &&
*values.get(smallest) != uint::MAX &&
*values.get(smallest) < name.len() + 2 &&
*values.get(smallest) <= max_distance &&
name != maybes.get(smallest).get() {
Some(maybes.get(smallest).get().to_strbuf())
} else {
None
}
}
fn resolve_expr(&mut self, expr: &Expr) {
// First, record candidate traits for this expression if it could
// result in the invocation of a method call.
self.record_candidate_traits_for_expr_if_necessary(expr);
// Next, resolve the node.
match expr.node {
// The interpretation of paths depends on whether the path has
// multiple elements in it or not.
ExprPath(ref path) => {
// This is a local path in the value namespace. Walk through
// scopes looking for it.
match self.resolve_path(expr.id, path, ValueNS, true) {
Some(def) => {
// Write the result into the def map.
debug!("(resolving expr) resolved `{}`",
self.path_idents_to_str(path));
// First-class methods are not supported yet; error
// out here.
match def {
(DefMethod(..), _) => {
self.resolve_error(expr.span,
"first-class methods \
are not supported");
self.session.span_note(expr.span,
"call the method \
using the `.` \
syntax");
}
_ => {}
}
self.record_def(expr.id, def);
}
None => {
let wrong_name = self.path_idents_to_str(path);
// Be helpful if the name refers to a struct
// (The pattern matching def_tys where the id is in self.structs
// matches on regular structs while excluding tuple- and enum-like
// structs, which wouldn't result in this error.)
match self.with_no_errors(|this|
this.resolve_path(expr.id, path, TypeNS, false)) {
Some((DefTy(struct_id), _))
if self.structs.contains_key(&struct_id) => {
self.resolve_error(expr.span,
format!("`{}` is a structure name, but \
this expression \
uses it like a function name",
wrong_name).as_slice());
self.session.span_note(expr.span,
format!("Did you mean to write: \
`{} \\{ /* fields */ \\}`?",
wrong_name).as_slice());
}
_ => {
let mut method_scope = false;
self.value_ribs.borrow().iter().rev().advance(|rib| {
let res = match *rib {
Rib { bindings: _, kind: MethodRibKind(_, _) } => true,
Rib { bindings: _, kind: OpaqueFunctionRibKind } => false,
_ => return true, // Keep advancing
};
method_scope = res;
false // Stop advancing
});
if method_scope && token::get_name(self.self_ident.name).get()
== wrong_name.as_slice() {
self.resolve_error(
expr.span,
"`self` is not available \
in a static method. Maybe a \
`self` argument is missing?");
} else {
let name = path_to_ident(path).name;
let mut msg = match self.find_fallback_in_self_type(name) {
NoSuggestion => {
// limit search to 5 to reduce the number
// of stupid suggestions
self.find_best_match_for_name(wrong_name.as_slice(), 5)
.map_or("".to_strbuf(),
|x| format!("`{}`", x))
}
Field =>
format!("`self.{}`", wrong_name),
Method
| TraitMethod =>
format!("to call `self.{}`", wrong_name),
StaticTraitMethod(path_str)
| StaticMethod(path_str) =>
format!("to call `{}::{}`", path_str, wrong_name)
};
if msg.len() > 0 {
msg = format!(" Did you mean {}?", msg)
}
self.resolve_error(
expr.span,
format!("unresolved name `{}`.{}",
wrong_name,
msg).as_slice());
}
}
}
}
}
visit::walk_expr(self, expr, ());
}
ExprFnBlock(fn_decl, block) |
ExprProc(fn_decl, block) => {
self.resolve_function(FunctionRibKind(expr.id, block.id),
Some(fn_decl), NoTypeParameters,
block);
}
ExprStruct(ref path, _, _) => {
// Resolve the path to the structure it goes to.
match self.resolve_path(expr.id, path, TypeNS, false) {
Some((DefTy(class_id), lp)) | Some((DefStruct(class_id), lp))
if self.structs.contains_key(&class_id) => {
let class_def = DefStruct(class_id);
self.record_def(expr.id, (class_def, lp));
}
Some(definition @ (DefVariant(_, class_id, _), _))
if self.structs.contains_key(&class_id) => {
self.record_def(expr.id, definition);
}
result => {
debug!("(resolving expression) didn't find struct \
def: {:?}", result);
let msg = format!("`{}` does not name a structure",
self.path_idents_to_str(path));
self.resolve_error(path.span, msg.as_slice());
}
}
visit::walk_expr(self, expr, ());
}
ExprLoop(_, Some(label)) => {
self.with_label_rib(|this| {
let def_like = DlDef(DefLabel(expr.id));
{
let label_ribs = this.label_ribs.borrow();
let length = label_ribs.len();
let rib = label_ribs.get(length - 1);
let renamed = mtwt::resolve(label);
rib.bindings.borrow_mut().insert(renamed, def_like);
}
visit::walk_expr(this, expr, ());
})
}
ExprForLoop(..) => fail!("non-desugared expr_for_loop"),
ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
let renamed = mtwt::resolve(label);
match self.search_ribs(self.label_ribs.borrow().as_slice(),
renamed, expr.span) {
None => {
self.resolve_error(
expr.span,
format!("use of undeclared label `{}`",
token::get_ident(label)).as_slice())
}
Some(DlDef(def @ DefLabel(_))) => {
// Since this def is a label, it is never read.
self.record_def(expr.id, (def, LastMod(AllPublic)))
}
Some(_) => {
self.session.span_bug(expr.span,
"label wasn't mapped to a \
label def!")
}
}
}
_ => {
visit::walk_expr(self, expr, ());
}
}
}
fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
match expr.node {
ExprField(_, ident, _) => {
// FIXME(#6890): Even though you can't treat a method like a
// field, we need to add any trait methods we find that match
// the field name so that we can do some nice error reporting
// later on in typeck.
let traits = self.search_for_traits_containing_method(ident.name);
self.trait_map.insert(expr.id, traits);
}
ExprMethodCall(ident, _, _) => {
debug!("(recording candidate traits for expr) recording \
traits for {}",
expr.id);
let traits = self.search_for_traits_containing_method(ident.node.name);
self.trait_map.insert(expr.id, traits);
}
_ => {
// Nothing to do.
}
}
}
fn search_for_traits_containing_method(&mut self, name: Name) -> Vec<DefId> {
debug!("(searching for traits containing method) looking for '{}'",
token::get_name(name));
fn add_trait_info(found_traits: &mut Vec<DefId>,
trait_def_id: DefId,
name: Name) {
debug!("(adding trait info) found trait {}:{} for method '{}'",
trait_def_id.krate,
trait_def_id.node,
token::get_name(name));
found_traits.push(trait_def_id);
}
let mut found_traits = Vec::new();
let mut search_module = self.current_module.clone();
loop {
// Look for the current trait.
match self.current_trait_ref {
Some((trait_def_id, _)) => {
let method_map = self.method_map.borrow();
if method_map.contains_key(&(name, trait_def_id)) {
add_trait_info(&mut found_traits, trait_def_id, name);
}
}
None => {} // Nothing to do.
}
// Look for trait children.
self.populate_module_if_necessary(&search_module);
{
let method_map = self.method_map.borrow();
for (_, child_names) in search_module.children.borrow().iter() {
let def = match child_names.def_for_namespace(TypeNS) {
Some(def) => def,
None => continue
};
let trait_def_id = match def {
DefTrait(trait_def_id) => trait_def_id,
_ => continue,
};
if method_map.contains_key(&(name, trait_def_id)) {
add_trait_info(&mut found_traits, trait_def_id, name);
}
}
}
// Look for imports.
for (_, import) in search_module.import_resolutions.borrow().iter() {
let target = match import.target_for_namespace(TypeNS) {
None => continue,
Some(target) => target,
};
let did = match target.bindings.def_for_namespace(TypeNS) {
Some(DefTrait(trait_def_id)) => trait_def_id,
Some(..) | None => continue,
};
if self.method_map.borrow().contains_key(&(name, did)) {
add_trait_info(&mut found_traits, did, name);
self.used_imports.insert((import.type_id, TypeNS));
}
}
match search_module.parent_link.clone() {
NoParentLink | ModuleParentLink(..) => break,
BlockParentLink(parent_module, _) => {
search_module = parent_module.upgrade().unwrap();
}
}
}
found_traits
}
fn record_def(&mut self, node_id: NodeId, (def, lp): (Def, LastPrivate)) {
debug!("(recording def) recording {:?} for {:?}, last private {:?}",
def, node_id, lp);
assert!(match lp {LastImport{..} => false, _ => true},
"Import should only be used for `use` directives");
self.last_private.insert(node_id, lp);
self.def_map.borrow_mut().insert_or_update_with(node_id, def, |_, old_value| {
// Resolve appears to "resolve" the same ID multiple
// times, so here is a sanity check it at least comes to
// the same conclusion! - nmatsakis
if def != *old_value {
self.session
.bug(format!("node_id {:?} resolved first to {:?} and \
then {:?}",
node_id,
*old_value,
def).as_slice());
}
});
}
fn enforce_default_binding_mode(&mut self,
pat: &Pat,
pat_binding_mode: BindingMode,
descr: &str) {
match pat_binding_mode {
BindByValue(_) => {}
BindByRef(..) => {
self.resolve_error(pat.span,
format!("cannot use `ref` binding mode \
with {}",
descr).as_slice());
}
}
}
//
// Unused import checking
//
// Although this is mostly a lint pass, it lives in here because it depends on
// resolve data structures and because it finalises the privacy information for
// `use` directives.
//
fn check_for_unused_imports(&mut self, krate: &ast::Crate) {
let mut visitor = UnusedImportCheckVisitor{ resolver: self };
visit::walk_crate(&mut visitor, krate, ());
}
fn check_for_item_unused_imports(&mut self, vi: &ViewItem) {
// Ignore is_public import statements because there's no way to be sure
// whether they're used or not. Also ignore imports with a dummy span
// because this means that they were generated in some fashion by the
// compiler and we don't need to consider them.
if vi.vis == Public { return }
if vi.span == DUMMY_SP { return }
match vi.node {
ViewItemExternCrate(..) => {} // ignore
ViewItemUse(ref p) => {
match p.node {
ViewPathSimple(_, _, id) => self.finalize_import(id, p.span),
ViewPathList(_, ref list, _) => {
for i in list.iter() {
self.finalize_import(i.node.id, i.span);
}
},
ViewPathGlob(_, id) => {
if !self.used_imports.contains(&(id, TypeNS)) &&
!self.used_imports.contains(&(id, ValueNS)) {
self.session
.add_lint(UnusedImports,
id,
p.span,
"unused import".to_strbuf());
}
},
}
}
}
}
// We have information about whether `use` (import) directives are actually used now.
// If an import is not used at all, we signal a lint error. If an import is only used
// for a single namespace, we remove the other namespace from the recorded privacy
// information. That means in privacy.rs, we will only check imports and namespaces
// which are used. In particular, this means that if an import could name either a
// public or private item, we will check the correct thing, dependent on how the import
// is used.
fn finalize_import(&mut self, id: NodeId, span: Span) {
debug!("finalizing import uses for {}",
self.session.codemap().span_to_snippet(span));
if !self.used_imports.contains(&(id, TypeNS)) &&
!self.used_imports.contains(&(id, ValueNS)) {
self.session.add_lint(UnusedImports,
id,
span,
"unused import".to_strbuf());
}
let (v_priv, t_priv) = match self.last_private.find(&id) {
Some(&LastImport {
value_priv: v,
value_used: _,
type_priv: t,
type_used: _
}) => (v, t),
Some(_) => {
fail!("we should only have LastImport for `use` directives")
}
_ => return,
};
let mut v_used = if self.used_imports.contains(&(id, ValueNS)) {
Used
} else {
Unused
};
let t_used = if self.used_imports.contains(&(id, TypeNS)) {
Used
} else {
Unused
};
match (v_priv, t_priv) {
// Since some items may be both in the value _and_ type namespaces (e.g., structs)
// we might have two LastPrivates pointing at the same thing. There is no point
// checking both, so lets not check the value one.
(Some(DependsOn(def_v)), Some(DependsOn(def_t))) if def_v == def_t => v_used = Unused,
_ => {},
}
self.last_private.insert(id, LastImport{value_priv: v_priv,
value_used: v_used,
type_priv: t_priv,
type_used: t_used});
}
//
// Diagnostics
//
// Diagnostics are not particularly efficient, because they're rarely
// hit.
//
/// A somewhat inefficient routine to obtain the name of a module.
fn module_to_str(&mut self, module: &Module) -> StrBuf {
let mut idents = Vec::new();
fn collect_mod(idents: &mut Vec<ast::Ident>, module: &Module) {
match module.parent_link {
NoParentLink => {}
ModuleParentLink(ref module, name) => {
idents.push(name);
collect_mod(idents, &*module.upgrade().unwrap());
}
BlockParentLink(ref module, _) => {
idents.push(special_idents::opaque);
collect_mod(idents, &*module.upgrade().unwrap());
}
}
}
collect_mod(&mut idents, module);
if idents.len() == 0 {
return "???".to_strbuf();
}
self.idents_to_str(idents.move_iter().rev()
.collect::<Vec<ast::Ident>>()
.as_slice())
}
#[allow(dead_code)] // useful for debugging
fn dump_module(&mut self, module_: Rc<Module>) {
debug!("Dump of module `{}`:", self.module_to_str(&*module_));
debug!("Children:");
self.populate_module_if_necessary(&module_);
for (&name, _) in module_.children.borrow().iter() {
debug!("* {}", token::get_name(name));
}
debug!("Import resolutions:");
let import_resolutions = module_.import_resolutions.borrow();
for (&name, import_resolution) in import_resolutions.iter() {
let value_repr;
match import_resolution.target_for_namespace(ValueNS) {
None => { value_repr = "".to_owned(); }
Some(_) => {
value_repr = " value:?".to_owned();
// FIXME #4954
}
}
let type_repr;
match import_resolution.target_for_namespace(TypeNS) {
None => { type_repr = "".to_owned(); }
Some(_) => {
type_repr = " type:?".to_owned();
// FIXME #4954
}
}
debug!("* {}:{}{}", token::get_name(name), value_repr, type_repr);
}
}
}
pub struct CrateMap {
pub def_map: DefMap,
pub exp_map2: ExportMap2,
pub trait_map: TraitMap,
pub external_exports: ExternalExports,
pub last_private_map: LastPrivateMap,
}
/// Entry point to crate resolution.
pub fn resolve_crate(session: &Session,
lang_items: &LanguageItems,
krate: &Crate)
-> CrateMap {
let mut resolver = Resolver(session, lang_items, krate.span);
resolver.resolve(krate);
let Resolver { def_map, export_map2, trait_map, last_private,
external_exports, .. } = resolver;
CrateMap {
def_map: def_map,
exp_map2: export_map2,
trait_map: trait_map,
external_exports: external_exports,
last_private_map: last_private,
}
}
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