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rust/src/librustc_resolve/lib.rs
bors 6fcf62831e Auto merge of #27349 - arielb1:constant-at, r=alexcrichton 
Fixes #27033
Fixes #27077 

r? @alexcrichton
2015-07-29 08:23:04 +00:00

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Rust
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// Copyright 2012-2015 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.
// Do not remove on snapshot creation. Needed for bootstrap. (Issue #22364)
#![cfg_attr(stage0, feature(custom_attribute))]
#![crate_name = "rustc_resolve"]
#![unstable(feature = "rustc_private")]
#![staged_api]
#![crate_type = "dylib"]
#![crate_type = "rlib"]
#![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
html_root_url = "http://doc.rust-lang.org/nightly/")]
#![feature(associated_consts)]
#![feature(rc_weak)]
#![feature(rustc_diagnostic_macros)]
#![feature(rustc_private)]
#![feature(slice_splits)]
#![feature(staged_api)]
#[macro_use] extern crate log;
#[macro_use] extern crate syntax;
#[macro_use] #[no_link] extern crate rustc_bitflags;
extern crate rustc;
use self::PatternBindingMode::*;
use self::Namespace::*;
use self::NamespaceResult::*;
use self::NameDefinition::*;
use self::ResolveResult::*;
use self::FallbackSuggestion::*;
use self::TypeParameters::*;
use self::RibKind::*;
use self::UseLexicalScopeFlag::*;
use self::ModulePrefixResult::*;
use self::AssocItemResolveResult::*;
use self::NameSearchType::*;
use self::BareIdentifierPatternResolution::*;
use self::ParentLink::*;
use self::ModuleKind::*;
use self::FallbackChecks::*;
use rustc::ast_map;
use rustc::session::Session;
use rustc::lint;
use rustc::metadata::csearch;
use rustc::metadata::decoder::{DefLike, DlDef, DlField, DlImpl};
use rustc::middle::def::*;
use rustc::middle::pat_util::pat_bindings;
use rustc::middle::privacy::*;
use rustc::middle::subst::{ParamSpace, FnSpace, TypeSpace};
use rustc::middle::ty::{Freevar, FreevarMap, TraitMap, GlobMap};
use rustc::util::nodemap::{NodeMap, NodeSet, DefIdSet, FnvHashMap};
use rustc::util::lev_distance::lev_distance;
use syntax::ast::{Arm, BindByRef, BindByValue, BindingMode, Block};
use syntax::ast::{ConstImplItem, Crate, CrateNum};
use syntax::ast::{DefId, Expr, ExprAgain, ExprBreak, ExprField};
use syntax::ast::{ExprLoop, ExprWhile, ExprMethodCall};
use syntax::ast::{ExprPath, ExprStruct, FnDecl};
use syntax::ast::{ForeignItemFn, ForeignItemStatic, Generics};
use syntax::ast::{Ident, ImplItem, Item, ItemConst, ItemEnum, ItemExternCrate};
use syntax::ast::{ItemFn, ItemForeignMod, ItemImpl, ItemMac, ItemMod, ItemStatic, ItemDefaultImpl};
use syntax::ast::{ItemStruct, ItemTrait, ItemTy, ItemUse};
use syntax::ast::{Local, MethodImplItem, Name, NodeId};
use syntax::ast::{Pat, PatEnum, PatIdent, PatLit, PatQPath};
use syntax::ast::{PatRange, PatStruct, Path, PrimTy};
use syntax::ast::{TraitRef, Ty, TyBool, TyChar, TyF32};
use syntax::ast::{TyF64, TyFloat, TyIs, TyI8, TyI16, TyI32, TyI64, TyInt};
use syntax::ast::{TyPath, TyPtr};
use syntax::ast::{TyRptr, TyStr, TyUs, TyU8, TyU16, TyU32, TyU64, TyUint};
use syntax::ast::TypeImplItem;
use syntax::ast;
use syntax::ast_util::{local_def, walk_pat};
use syntax::attr::AttrMetaMethods;
use syntax::ext::mtwt;
use syntax::parse::token::{self, special_names, special_idents};
use syntax::ptr::P;
use syntax::codemap::{self, Span, Pos};
use syntax::visit::{self, Visitor};
use std::collections::{HashMap, HashSet};
use std::collections::hash_map::Entry::{Occupied, Vacant};
use std::cell::{Cell, RefCell};
use std::fmt;
use std::mem::replace;
use std::rc::{Rc, Weak};
use std::usize;
use resolve_imports::{Target, ImportDirective, ImportResolution};
use resolve_imports::Shadowable;
// NB: This module needs to be declared first so diagnostics are
// registered before they are used.
pub mod diagnostics;
mod check_unused;
mod record_exports;
mod build_reduced_graph;
mod resolve_imports;
pub enum ResolutionError<'a> {
/// error E0401: can't use type parameters from outer function
TypeParametersFromOuterFunction,
/// error E0402: cannot use an outer type parameter in this context
OuterTypeParameterContext,
/// error E0403: the name is already used for a type parameter in this type parameter list
NameAlreadyUsedInTypeParameterList(Name),
/// error E0404: is not a trait
IsNotATrait(&'a str),
/// error E0405: use of undeclared trait name
UndeclaredTraitName(&'a str),
/// error E0406: undeclared associated type
UndeclaredAssociatedType,
/// error E0407: method is not a member of trait
MethodNotMemberOfTrait(Name, &'a str),
/// error E0437: type is not a member of trait
TypeNotMemberOfTrait(Name, &'a str),
/// error E0438: const is not a member of trait
ConstNotMemberOfTrait(Name, &'a str),
/// error E0408: variable `{}` from pattern #1 is not bound in pattern
VariableNotBoundInPattern(Name, usize),
/// error E0409: variable is bound with different mode in pattern #{} than in pattern #1
VariableBoundWithDifferentMode(Name, usize),
/// error E0410: variable from pattern is not bound in pattern #1
VariableNotBoundInParentPattern(Name, usize),
/// error E0411: use of `Self` outside of an impl or trait
SelfUsedOutsideImplOrTrait,
/// error E0412: use of undeclared
UseOfUndeclared(&'a str, &'a str),
/// error E0413: declaration shadows an enum variant or unit-like struct in scope
DeclarationShadowsEnumVariantOrUnitLikeStruct(Name),
/// error E0414: only irrefutable patterns allowed here
OnlyIrrefutablePatternsAllowedHere,
/// error E0415: identifier is bound more than once in this parameter list
IdentifierBoundMoreThanOnceInParameterList(&'a str),
/// error E0416: identifier is bound more than once in the same pattern
IdentifierBoundMoreThanOnceInSamePattern(&'a str),
/// error E0417: static variables cannot be referenced in a pattern
StaticVariableReference,
/// error E0418: is not an enum variant, struct or const
NotAnEnumVariantStructOrConst(&'a str),
/// error E0419: unresolved enum variant, struct or const
UnresolvedEnumVariantStructOrConst(&'a str),
/// error E0420: is not an associated const
NotAnAssociatedConst(&'a str),
/// error E0421: unresolved associated const
UnresolvedAssociatedConst(&'a str),
/// error E0422: does not name a struct
DoesNotNameAStruct(&'a str),
/// error E0423: is a struct variant name, but this expression uses it like a function name
StructVariantUsedAsFunction(&'a str),
/// error E0424: `self` is not available in a static method
SelfNotAvailableInStaticMethod,
/// error E0425: unresolved name
UnresolvedName(&'a str, &'a str),
/// error E0426: use of undeclared label
UndeclaredLabel(&'a str),
/// error E0427: cannot use `ref` binding mode with ...
CannotUseRefBindingModeWith(&'a str),
/// error E0428: duplicate definition
DuplicateDefinition(&'a str, Name),
/// error E0429: `self` imports are only allowed within a { } list
SelfImportsOnlyAllowedWithin,
/// error E0430: `self` import can only appear once in the list
SelfImportCanOnlyAppearOnceInTheList,
/// error E0431: `self` import can only appear in an import list with a non-empty prefix
SelfImportOnlyInImportListWithNonEmptyPrefix,
/// error E0432: unresolved import
UnresolvedImport(Option<(&'a str, Option<&'a str>)>),
/// error E0433: failed to resolve
FailedToResolve(&'a str),
/// error E0434: can't capture dynamic environment in a fn item
CannotCaptureDynamicEnvironmentInFnItem,
/// error E0435: attempt to use a non-constant value in a constant
AttemptToUseNonConstantValueInConstant,
}
fn resolve_error<'b, 'a:'b, 'tcx:'a>(resolver: &'b Resolver<'a, 'tcx>, span: syntax::codemap::Span,
resolution_error: ResolutionError<'b>) {
if !resolver.emit_errors {
return;
}
match resolution_error {
ResolutionError::TypeParametersFromOuterFunction => {
span_err!(resolver.session, span, E0401, "can't use type parameters from \
outer function; try using a local \
type parameter instead");
},
ResolutionError::OuterTypeParameterContext => {
span_err!(resolver.session, span, E0402,
"cannot use an outer type parameter in this context");
},
ResolutionError::NameAlreadyUsedInTypeParameterList(name) => {
span_err!(resolver.session, span, E0403,
"the name `{}` is already used for a type \
parameter in this type parameter list", name);
},
ResolutionError::IsNotATrait(name) => {
span_err!(resolver.session, span, E0404,
"`{}` is not a trait",
name);
},
ResolutionError::UndeclaredTraitName(name) => {
span_err!(resolver.session, span, E0405,
"use of undeclared trait name `{}`",
name);
},
ResolutionError::UndeclaredAssociatedType => {
span_err!(resolver.session, span, E0406, "undeclared associated type");
},
ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
span_err!(resolver.session, span, E0407,
"method `{}` is not a member of trait `{}`",
method,
trait_);
},
ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
span_err!(resolver.session, span, E0437,
"type `{}` is not a member of trait `{}`",
type_,
trait_);
},
ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
span_err!(resolver.session, span, E0438,
"const `{}` is not a member of trait `{}`",
const_,
trait_);
},
ResolutionError::VariableNotBoundInPattern(variable_name, pattern_number) => {
span_err!(resolver.session, span, E0408,
"variable `{}` from pattern #1 is not bound in pattern #{}",
variable_name,
pattern_number);
},
ResolutionError::VariableBoundWithDifferentMode(variable_name, pattern_number) => {
span_err!(resolver.session, span, E0409,
"variable `{}` is bound with different \
mode in pattern #{} than in pattern #1",
variable_name,
pattern_number);
},
ResolutionError::VariableNotBoundInParentPattern(variable_name, pattern_number) => {
span_err!(resolver.session, span, E0410,
"variable `{}` from pattern #{} is not bound in pattern #1",
variable_name,
pattern_number);
},
ResolutionError::SelfUsedOutsideImplOrTrait => {
span_err!(resolver.session, span, E0411, "use of `Self` outside of an impl or trait");
},
ResolutionError::UseOfUndeclared(kind, name) => {
span_err!(resolver.session, span, E0412,
"use of undeclared {} `{}`",
kind,
name);
},
ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(name) => {
span_err!(resolver.session, span, E0413,
"declaration of `{}` shadows an enum variant or unit-like struct in \
scope",
name);
},
ResolutionError::OnlyIrrefutablePatternsAllowedHere => {
span_err!(resolver.session, span, E0414, "only irrefutable patterns allowed here");
},
ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
span_err!(resolver.session, span, E0415,
"identifier `{}` is bound more than once in this parameter list",
identifier);
},
ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
span_err!(resolver.session, span, E0416,
"identifier `{}` is bound more than once in the same pattern",
identifier);
},
ResolutionError::StaticVariableReference => {
span_err!(resolver.session, span, E0417, "static variables cannot be \
referenced in a pattern, \
use a `const` instead");
},
ResolutionError::NotAnEnumVariantStructOrConst(name) => {
span_err!(resolver.session, span, E0418,
"`{}` is not an enum variant, struct or const",
name);
},
ResolutionError::UnresolvedEnumVariantStructOrConst(name) => {
span_err!(resolver.session, span, E0419,
"unresolved enum variant, struct or const `{}`",
name);
},
ResolutionError::NotAnAssociatedConst(name) => {
span_err!(resolver.session, span, E0420,
"`{}` is not an associated const",
name);
},
ResolutionError::UnresolvedAssociatedConst(name) => {
span_err!(resolver.session, span, E0421,
"unresolved associated const `{}`",
name);
},
ResolutionError::DoesNotNameAStruct(name) => {
span_err!(resolver.session, span, E0422, "`{}` does not name a structure", name);
},
ResolutionError::StructVariantUsedAsFunction(path_name) => {
span_err!(resolver.session, span, E0423,
"`{}` is a struct variant name, but \
this expression \
uses it like a function name",
path_name);
},
ResolutionError::SelfNotAvailableInStaticMethod => {
span_err!(resolver.session, span, E0424, "`self` is not available in a static method. \
Maybe a `self` argument is missing?");
},
ResolutionError::UnresolvedName(path, name) => {
span_err!(resolver.session, span, E0425,
"unresolved name `{}`{}",
path,
name);
},
ResolutionError::UndeclaredLabel(name) => {
span_err!(resolver.session, span, E0426,
"use of undeclared label `{}`",
name);
},
ResolutionError::CannotUseRefBindingModeWith(descr) => {
span_err!(resolver.session, span, E0427,
"cannot use `ref` binding mode with {}",
descr);
},
ResolutionError::DuplicateDefinition(namespace, name) => {
span_err!(resolver.session, span, E0428,
"duplicate definition of {} `{}`",
namespace,
name);
},
ResolutionError::SelfImportsOnlyAllowedWithin => {
span_err!(resolver.session, span, E0429, "{}",
"`self` imports are only allowed within a { } list");
},
ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
span_err!(resolver.session, span, E0430,
"`self` import can only appear once in the list");
},
ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
span_err!(resolver.session, span, E0431,
"`self` import can only appear in an import list with a \
non-empty prefix");
}
ResolutionError::UnresolvedImport(name) => {
let msg = match name {
Some((n, Some(p))) => format!("unresolved import `{}`{}", n, p),
Some((n, None)) => format!("unresolved import (maybe you meant `{}::*`?)", n),
None => "unresolved import".to_owned()
};
span_err!(resolver.session, span, E0432, "{}", msg);
},
ResolutionError::FailedToResolve(msg) => {
span_err!(resolver.session, span, E0433, "failed to resolve. {}", msg);
},
ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
span_err!(resolver.session, span, E0434, "{}",
"can't capture dynamic environment in a fn item; \
use the || { ... } closure form instead");
},
ResolutionError::AttemptToUseNonConstantValueInConstant =>{
span_err!(resolver.session, span, E0435,
"attempt to use a non-constant value in a constant");
},
}
}
#[derive(Copy, Clone)]
struct BindingInfo {
span: Span,
binding_mode: BindingMode,
}
// Map from the name in a pattern to its binding mode.
type BindingMap = HashMap<Name, BindingInfo>;
#[derive(Copy, Clone, PartialEq)]
enum PatternBindingMode {
RefutableMode,
LocalIrrefutableMode,
ArgumentIrrefutableMode,
}
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
enum Namespace {
TypeNS,
ValueNS
}
/// A NamespaceResult represents the result of resolving an import in
/// a particular namespace. The result is either definitely-resolved,
/// definitely- unresolved, or unknown.
#[derive(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 {
// The name was unbound.
NoNameDefinition,
// The name identifies an immediate child.
ChildNameDefinition(Def, LastPrivate),
// The name identifies an import.
ImportNameDefinition(Def, LastPrivate),
}
impl<'a, 'v, 'tcx> Visitor<'v> for Resolver<'a, 'tcx> {
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);
}
fn visit_generics(&mut self, generics: &Generics) {
self.resolve_generics(generics);
}
fn visit_poly_trait_ref(&mut self,
tref: &ast::PolyTraitRef,
m: &ast::TraitBoundModifier) {
match self.resolve_trait_reference(tref.trait_ref.ref_id, &tref.trait_ref.path, 0) {
Ok(def) => self.record_def(tref.trait_ref.ref_id, def),
Err(_) => { /* error already reported */ }
}
visit::walk_poly_trait_ref(self, tref, m);
}
fn visit_variant(&mut self, variant: &ast::Variant, generics: &Generics) {
if let Some(ref dis_expr) = variant.node.disr_expr {
// resolve the discriminator expr as a constant
self.with_constant_rib(|this| {
this.visit_expr(&**dis_expr);
});
}
// `visit::walk_variant` without the discriminant expression.
match variant.node.kind {
ast::TupleVariantKind(ref variant_arguments) => {
for variant_argument in variant_arguments {
self.visit_ty(&*variant_argument.ty);
}
}
ast::StructVariantKind(ref struct_definition) => {
self.visit_struct_def(&**struct_definition,
variant.node.name,
generics,
variant.node.id);
}
}
}
fn visit_foreign_item(&mut self, foreign_item: &ast::ForeignItem) {
let type_parameters = match foreign_item.node {
ForeignItemFn(_, ref generics) => {
HasTypeParameters(generics, FnSpace, ItemRibKind)
}
ForeignItemStatic(..) => NoTypeParameters
};
self.with_type_parameter_rib(type_parameters, |this| {
visit::walk_foreign_item(this, foreign_item);
});
}
fn visit_fn(&mut self,
function_kind: visit::FnKind<'v>,
declaration: &'v FnDecl,
block: &'v Block,
_: Span,
node_id: NodeId) {
let rib_kind = match function_kind {
visit::FkItemFn(_, generics, _, _, _, _) => {
self.visit_generics(generics);
ItemRibKind
}
visit::FkMethod(_, sig, _) => {
self.visit_generics(&sig.generics);
self.visit_explicit_self(&sig.explicit_self);
MethodRibKind
}
visit::FkFnBlock(..) => ClosureRibKind(node_id)
};
self.resolve_function(rib_kind, declaration, block);
}
}
type ErrorMessage = Option<(Span, String)>;
enum ResolveResult<T> {
Failed(ErrorMessage), // Failed to resolve the name, optional helpful error message.
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,
TraitItem,
StaticMethod(String),
TraitMethod(String),
}
#[derive(Copy, Clone)]
enum TypeParameters<'a> {
NoTypeParameters,
HasTypeParameters(
// Type parameters.
&'a Generics,
// Identifies the things that these parameters
// were declared on (type, fn, etc)
ParamSpace,
// The kind of the rib used for type parameters.
RibKind)
}
// The rib kind controls the translation of local
// definitions (`DefLocal`) to upvars (`DefUpvar`).
#[derive(Copy, Clone, Debug)]
enum RibKind {
// No translation needs to be applied.
NormalRibKind,
// We passed through a closure scope at the given node ID.
// Translate upvars as appropriate.
ClosureRibKind(NodeId /* func 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).
MethodRibKind,
// We passed through an item scope. Disallow upvars.
ItemRibKind,
// We're in a constant item. Can't refer to dynamic stuff.
ConstantItemRibKind
}
#[derive(Copy, Clone)]
enum UseLexicalScopeFlag {
DontUseLexicalScope,
UseLexicalScope
}
enum ModulePrefixResult {
NoPrefixFound,
PrefixFound(Rc<Module>, usize)
}
#[derive(Copy, Clone)]
enum AssocItemResolveResult {
/// Syntax such as `<T>::item`, which can't be resolved until type
/// checking.
TypecheckRequired,
/// We should have been able to resolve the associated item.
ResolveAttempt(Option<PathResolution>),
}
#[derive(Copy, Clone, PartialEq)]
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,
}
#[derive(Copy, Clone)]
enum BareIdentifierPatternResolution {
FoundStructOrEnumVariant(Def, LastPrivate),
FoundConst(Def, LastPrivate),
BareIdentifierPatternUnresolved
}
/// One local scope.
#[derive(Debug)]
struct Rib {
bindings: HashMap<Name, DefLike>,
kind: RibKind,
}
impl Rib {
fn new(kind: RibKind) -> Rib {
Rib {
bindings: HashMap::new(),
kind: kind
}
}
}
/// The link from a module up to its nearest parent node.
#[derive(Clone,Debug)]
enum ParentLink {
NoParentLink,
ModuleParentLink(Weak<Module>, Name),
BlockParentLink(Weak<Module>, NodeId)
}
/// The type of module this is.
#[derive(Copy, Clone, PartialEq, Debug)]
enum ModuleKind {
NormalModuleKind,
TraitModuleKind,
EnumModuleKind,
TypeModuleKind,
AnonymousModuleKind,
}
/// One node in the tree of modules.
pub 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<usize>,
// The index of the import we're resolving.
resolved_import_count: Cell<usize>,
// 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()),
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()
}
}
impl fmt::Debug for Module {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{:?}, kind: {:?}, {}",
self.def_id,
self.kind,
if self.is_public { "public" } else { "private" } )
}
}
bitflags! {
#[derive(Debug)]
flags DefModifiers: u8 {
const PUBLIC = 1 << 0,
const IMPORTABLE = 1 << 1,
}
}
// Records a possibly-private type definition.
#[derive(Clone,Debug)]
struct TypeNsDef {
modifiers: DefModifiers, // 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.
#[derive(Clone, Copy, Debug)]
struct ValueNsDef {
modifiers: DefModifiers, // 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.
#[derive(Debug)]
pub struct NameBindings {
type_def: RefCell<Option<TypeNsDef>>, //< Meaning in type namespace.
value_def: RefCell<Option<ValueNsDef>>, //< Meaning in value namespace.
}
impl NameBindings {
fn new() -> NameBindings {
NameBindings {
type_def: RefCell::new(None),
value_def: RefCell::new(None),
}
}
/// 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 modifiers = if is_public {
DefModifiers::PUBLIC
} else {
DefModifiers::empty()
} | DefModifiers::IMPORTABLE;
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 {
modifiers: modifiers,
module_def: Some(module_),
type_def: None,
type_span: Some(sp)
});
}
Some(type_def) => {
*self.type_def.borrow_mut() = Some(TypeNsDef {
modifiers: modifiers,
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 modifiers = if is_public {
DefModifiers::PUBLIC
} else {
DefModifiers::empty()
} | DefModifiers::IMPORTABLE;
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 {
modifiers: modifiers,
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 {
modifiers: modifiers,
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, modifiers: DefModifiers) {
debug!("defining type for def {:?} with modifiers {:?}", def, modifiers);
// 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),
modifiers: modifiers,
});
}
Some(type_def) => {
*self.type_def.borrow_mut() = Some(TypeNsDef {
module_def: type_def.module_def,
type_def: Some(def),
type_span: Some(sp),
modifiers: modifiers,
});
}
}
}
/// Records a value definition.
fn define_value(&self, def: Def, sp: Span, modifiers: DefModifiers) {
debug!("defining value for def {:?} with modifiers {:?}", def, modifiers);
*self.value_def.borrow_mut() = Some(ValueNsDef {
def: def,
value_span: Some(sp),
modifiers: modifiers,
});
}
/// 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. Panics if this node does not have a module
/// definition.
fn get_module(&self) -> Rc<Module> {
match self.get_module_if_available() {
None => {
panic!("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 {
self.defined_in_namespace_with(namespace, DefModifiers::PUBLIC)
}
fn defined_in_namespace_with(&self, namespace: Namespace, modifiers: DefModifiers) -> bool {
match namespace {
TypeNS => match *self.type_def.borrow() {
Some(ref def) => def.modifiers.contains(modifiers), None => false
},
ValueNS => match *self.value_def.borrow() {
Some(ref def) => def.modifiers.contains(modifiers), 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 is_public(&self, namespace: Namespace) -> bool {
match namespace {
TypeNS => {
let type_def = self.type_def.borrow();
type_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
}
ValueNS => {
let value_def = self.value_def.borrow();
value_def.as_ref().unwrap().modifiers.contains(DefModifiers::PUBLIC)
}
}
}
}
/// Interns the names of the primitive types.
struct PrimitiveTypeTable {
primitive_types: HashMap<Name, PrimTy>,
}
impl PrimitiveTypeTable {
fn new() -> 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("isize", TyInt(TyIs));
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("usize", TyUint(TyUs));
table.intern("u8", TyUint(TyU8));
table.intern("u16", TyUint(TyU16));
table.intern("u32", TyUint(TyU32));
table.intern("u64", TyUint(TyU64));
table
}
fn intern(&mut self, string: &str, primitive_type: PrimTy) {
self.primitive_types.insert(token::intern(string), primitive_type);
}
}
/// The main resolver class.
pub struct Resolver<'a, 'tcx:'a> {
session: &'a Session,
ast_map: &'a ast_map::Map<'tcx>,
graph_root: NameBindings,
trait_item_map: FnvHashMap<(Name, DefId), DefId>,
structs: FnvHashMap<DefId, Vec<Name>>,
// The number of imports that are currently unresolved.
unresolved_imports: usize,
// 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: Vec<Rib>,
// The current set of local scopes, for types.
type_ribs: Vec<Rib>,
// The current set of local scopes, for labels.
label_ribs: 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 idents for the primitive types.
primitive_type_table: PrimitiveTypeTable,
def_map: DefMap,
freevars: RefCell<FreevarMap>,
freevars_seen: RefCell<NodeMap<NodeSet>>,
export_map: ExportMap,
trait_map: TraitMap,
external_exports: ExternalExports,
// 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,
make_glob_map: bool,
// Maps imports to the names of items actually imported (this actually maps
// all imports, but only glob imports are actually interesting).
glob_map: GlobMap,
used_imports: HashSet<(NodeId, Namespace)>,
used_crates: HashSet<CrateNum>,
}
#[derive(PartialEq)]
enum FallbackChecks {
Everything,
OnlyTraitAndStatics
}
impl<'a, 'tcx> Resolver<'a, 'tcx> {
fn new(session: &'a Session,
ast_map: &'a ast_map::Map<'tcx>,
crate_span: Span,
make_glob_map: MakeGlobMap) -> Resolver<'a, 'tcx> {
let graph_root = NameBindings::new();
graph_root.define_module(NoParentLink,
Some(DefId { krate: 0, node: 0 }),
NormalModuleKind,
false,
true,
crate_span);
let current_module = graph_root.get_module();
Resolver {
session: session,
ast_map: ast_map,
// The outermost module has def ID 0; this is not reflected in the
// AST.
graph_root: graph_root,
trait_item_map: FnvHashMap(),
structs: FnvHashMap(),
unresolved_imports: 0,
current_module: current_module,
value_ribs: Vec::new(),
type_ribs: Vec::new(),
label_ribs: Vec::new(),
current_trait_ref: None,
current_self_type: None,
primitive_type_table: PrimitiveTypeTable::new(),
def_map: RefCell::new(NodeMap()),
freevars: RefCell::new(NodeMap()),
freevars_seen: RefCell::new(NodeMap()),
export_map: NodeMap(),
trait_map: NodeMap(),
used_imports: HashSet::new(),
used_crates: HashSet::new(),
external_exports: DefIdSet(),
emit_errors: true,
make_glob_map: make_glob_map == MakeGlobMap::Yes,
glob_map: HashMap::new(),
}
}
#[inline]
fn record_import_use(&mut self, import_id: NodeId, name: Name) {
if !self.make_glob_map {
return;
}
if self.glob_map.contains_key(&import_id) {
self.glob_map.get_mut(&import_id).unwrap().insert(name);
return;
}
let mut new_set = HashSet::new();
new_set.insert(name);
self.glob_map.insert(import_id, new_set);
}
fn get_trait_name(&self, did: DefId) -> Name {
if did.krate == ast::LOCAL_CRATE {
self.ast_map.expect_item(did.node).ident.name
} else {
csearch::get_trait_name(&self.session.cstore, did)
}
}
fn create_name_bindings_from_module(module: Rc<Module>) -> NameBindings {
NameBindings {
type_def: RefCell::new(Some(TypeNsDef {
modifiers: DefModifiers::IMPORTABLE,
module_def: Some(module),
type_def: None,
type_span: None
})),
value_def: RefCell::new(None),
}
}
/// Checks that the names of external crates don't collide with other
/// external crates.
fn check_for_conflicts_between_external_crates(&self,
module: &Module,
name: Name,
span: Span) {
if module.external_module_children.borrow().contains_key(&name) {
span_err!(self.session, span, E0259,
"an external crate named `{}` has already \
been imported into this module",
name);
}
}
/// Checks that the names of items don't collide with external crates.
fn check_for_conflicts_between_external_crates_and_items(&self,
module: &Module,
name: Name,
span: Span) {
if module.external_module_children.borrow().contains_key(&name) {
span_err!(self.session, span, E0260,
"the name `{}` conflicts with an external \
crate that has been imported into this \
module",
name);
}
}
/// Resolves the given module path from the given root `module_`.
fn resolve_module_path_from_root(&mut self,
module_: Rc<Module>,
module_path: &[Name],
index: usize,
span: Span,
name_search_type: NameSearchType,
lp: LastPrivate)
-> ResolveResult<(Rc<Module>, LastPrivate)> {
fn search_parent_externals(needle: Name, module: &Rc<Module>)
-> Option<Rc<Module>> {
match module.external_module_children.borrow().get(&needle) {
Some(_) => Some(module.clone()),
None => match module.parent_link {
ModuleParentLink(ref parent, _) => {
search_parent_externals(needle, &parent.upgrade().unwrap())
}
_ => None
}
}
}
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,
TypeNS,
name_search_type,
false) {
Failed(None) => {
let segment_name = name.as_str();
let module_name = module_to_string(&*search_module);
let mut span = span;
let msg = if "???" == &module_name[..] {
span.hi = span.lo + Pos::from_usize(segment_name.len());
match search_parent_externals(name,
&self.current_module) {
Some(module) => {
let path_str = names_to_string(module_path);
let target_mod_str = module_to_string(&*module);
let current_mod_str =
module_to_string(&*self.current_module);
let prefix = if target_mod_str == current_mod_str {
"self::".to_string()
} else {
format!("{}::", target_mod_str)
};
format!("Did you mean `{}{}`?", prefix, path_str)
},
None => format!("Maybe a missing `extern crate {}`?",
segment_name),
}
} else {
format!("Could not find `{}` in `{}`",
segment_name,
module_name)
};
return Failed(Some((span, msg)));
}
Failed(err) => return Failed(err),
Indeterminate => {
debug!("(resolving module path for import) module \
resolution is indeterminate: {}",
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 => {
let msg = format!("Not a module `{}`",
name);
return Failed(Some((span, msg)));
}
Some(ref module_def) => {
search_module = module_def.clone();
// track extern crates for unused_extern_crate lint
if let Some(did) = module_def.def_id.get() {
self.used_crates.insert(did.krate);
}
// Keep track of the closest
// private module used when
// resolving this import chain.
if !used_proxy && !search_module.is_public {
if let Some(did) = search_module.def_id.get() {
closest_private = LastMod(DependsOn(did));
}
}
}
}
}
None => {
// There are no type bindings at all.
let msg = format!("Not a module `{}`",
name);
return Failed(Some((span, msg)));
}
}
}
}
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: &[Name],
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 `{}`",
names_to_string(module_path),
module_to_string(&*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(None) => {
let mpath = names_to_string(module_path);
let mpath = &mpath[..];
match mpath.rfind(':') {
Some(idx) => {
let msg = format!("Could not find `{}` in `{}`",
// idx +- 1 to account for the
// colons on either side
&mpath[idx + 1..],
&mpath[..idx - 1]);
return Failed(Some((span, msg)));
},
None => {
return Failed(None)
}
}
}
Failed(err) => return Failed(err),
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.
match self.resolve_module_in_lexical_scope(module_,
module_path[0]) {
Failed(err) => return Failed(err),
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: Name,
namespace: Namespace)
-> ResolveResult<(Target, bool)> {
debug!("(resolving item in lexical scope) resolving `{}` in \
namespace {:?} in `{}`",
name,
namespace,
module_to_string(&*module_));
// The current module node is handled specially. First, check for
// its immediate children.
build_reduced_graph::populate_module_if_necessary(self, &module_);
match module_.children.borrow().get(&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(),
Shadowable::Never),
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.
if let Some(import_resolution) = module_.import_resolutions.borrow().get(&name) {
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");
// track used imports and extern crates as well
let id = import_resolution.id(namespace);
self.used_imports.insert((id, namespace));
self.record_import_use(id, name);
if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
self.used_crates.insert(kid);
}
return Success((target, false));
}
}
}
// Search for external modules.
if namespace == TypeNS {
// FIXME (21114): In principle unclear `child` *has* to be lifted.
let child = module_.external_module_children.borrow().get(&name).cloned();
if let Some(module) = child {
let name_bindings =
Rc::new(Resolver::create_name_bindings_from_module(module));
debug!("lower name bindings succeeded");
return Success((Target::new(module_,
name_bindings,
Shadowable::Never),
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(None);
}
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(None);
}
TraitModuleKind |
EnumModuleKind |
TypeModuleKind |
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,
namespace,
PathSearch,
true) {
Failed(Some((span, msg))) => {
resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
},
Failed(None) => (), // 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: Name)
-> 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(None);
}
Some(ref module_def) => {
return Success(module_def.clone());
}
}
}
None => {
debug!("!!! (resolving module in lexical scope) module
wasn't actually a module!");
return Failed(None);
}
}
}
Indeterminate => {
debug!("(resolving module in lexical scope) indeterminate; \
bailing");
return Indeterminate;
}
Failed(err) => {
debug!("(resolving module in lexical scope) failed to resolve");
return Failed(err);
}
}
}
/// 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),
TraitModuleKind |
EnumModuleKind |
TypeModuleKind |
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_,
TraitModuleKind |
EnumModuleKind |
TypeModuleKind |
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: &[Name])
-> ResolveResult<ModulePrefixResult> {
// Start at the current module if we see `self` or `super`, or at the
// top of the crate otherwise.
let mut i = match &*module_path[0].as_str() {
"self" => 1,
"super" => 0,
_ => return Success(NoPrefixFound),
};
let mut containing_module = self.get_nearest_normal_module_parent_or_self(module_);
// Now loop through all the `super`s we find.
while i < module_path.len() && "super" == module_path[i].as_str() {
debug!("(resolving module prefix) resolving `super` at {}",
module_to_string(&*containing_module));
match self.get_nearest_normal_module_parent(containing_module) {
None => return Failed(None),
Some(new_module) => {
containing_module = new_module;
i += 1;
}
}
}
debug!("(resolving module prefix) finished resolving prefix at {}",
module_to_string(&*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 `{}`",
name,
module_to_string(&*module_));
// First, check the direct children of the module.
build_reduced_graph::populate_module_if_necessary(self, &module_);
match module_.children.borrow().get(&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(),
Shadowable::Never),
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().get(&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");
// track used imports and extern crates as well
let id = import_resolution.id(namespace);
self.used_imports.insert((id, namespace));
self.record_import_use(id, name);
if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
self.used_crates.insert(kid);
}
return Success((target, true));
}
}
}
Some(..) | None => {} // Continue.
}
// Finally, search through external children.
if namespace == TypeNS {
// FIXME (21114): In principle unclear `child` *has* to be lifted.
let child = module_.external_module_children.borrow().get(&name).cloned();
if let Some(module) = child {
let name_bindings =
Rc::new(Resolver::create_name_bindings_from_module(module));
return Success((Target::new(module_,
name_bindings,
Shadowable::Never),
false));
}
}
// We're out of luck.
debug!("(resolving name in module) failed to resolve `{}`",
name);
return Failed(None);
}
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)[index].span)
.unwrap();
if sn.contains("::") {
resolve_error(self,
(*imports)[index].span,
ResolutionError::UnresolvedImport(None));
} else {
resolve_error(self,
(*imports)[index].span,
ResolutionError::UnresolvedImport(Some((&*sn, None))));
}
}
// Descend into children and anonymous children.
build_reduced_graph::populate_module_if_necessary(self, &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());
}
}
// 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<F>(&mut self, name: Option<Name>, f: F) where
F: FnOnce(&mut Resolver),
{
let orig_module = self.current_module.clone();
// Move down in the graph.
match name {
None => {
// Nothing to do.
}
Some(name) => {
build_reduced_graph::populate_module_if_necessary(self, &orig_module);
match orig_module.children.borrow().get(&name) {
None => {
debug!("!!! (with scope) didn't find `{}` in `{}`",
name,
module_to_string(&*orig_module));
}
Some(name_bindings) => {
match (*name_bindings).get_module_if_available() {
None => {
debug!("!!! (with scope) didn't find module \
for `{}` in `{}`",
name,
module_to_string(&*orig_module));
}
Some(module_) => {
self.current_module = module_;
}
}
}
}
}
}
f(self);
self.current_module = orig_module;
}
/// Wraps the given definition in the appropriate number of `DefUpvar`
/// wrappers.
fn upvarify(&self,
ribs: &[Rib],
def_like: DefLike,
span: Span)
-> Option<DefLike> {
let mut def = match def_like {
DlDef(def) => def,
_ => return Some(def_like)
};
match def {
DefUpvar(..) => {
self.session.span_bug(span,
&format!("unexpected {:?} in bindings", def))
}
DefLocal(node_id) => {
for rib in ribs {
match rib.kind {
NormalRibKind => {
// Nothing to do. Continue.
}
ClosureRibKind(function_id) => {
let prev_def = def;
def = DefUpvar(node_id, function_id);
let mut seen = self.freevars_seen.borrow_mut();
let seen = match seen.entry(function_id) {
Occupied(v) => v.into_mut(),
Vacant(v) => v.insert(NodeSet()),
};
if seen.contains(&node_id) {
continue;
}
match self.freevars.borrow_mut().entry(function_id) {
Occupied(v) => v.into_mut(),
Vacant(v) => v.insert(vec![]),
}.push(Freevar { def: prev_def, span: span });
seen.insert(node_id);
}
ItemRibKind | MethodRibKind => {
// This was an attempt to access an upvar inside a
// named function item. This is not allowed, so we
// report an error.
resolve_error(
self,
span,
ResolutionError::CannotCaptureDynamicEnvironmentInFnItem
);
return None;
}
ConstantItemRibKind => {
// Still doesn't deal with upvars
resolve_error(
self,
span,
ResolutionError::AttemptToUseNonConstantValueInConstant
);
return None;
}
}
}
}
DefTyParam(..) | DefSelfTy(..) => {
for rib in ribs {
match rib.kind {
NormalRibKind | MethodRibKind | ClosureRibKind(..) => {
// Nothing to do. Continue.
}
ItemRibKind => {
// This was an attempt to use a type parameter outside
// its scope.
resolve_error(self,
span,
ResolutionError::TypeParametersFromOuterFunction);
return None;
}
ConstantItemRibKind => {
// see #9186
resolve_error(self, span, ResolutionError::OuterTypeParameterContext);
return None;
}
}
}
}
_ => {}
}
Some(DlDef(def))
}
/// Searches the current set of local scopes and
/// applies translations for closures.
fn search_ribs(&self,
ribs: &[Rib],
name: Name,
span: Span)
-> Option<DefLike> {
// FIXME #4950: Try caching?
for (i, rib) in ribs.iter().enumerate().rev() {
if let Some(def_like) = rib.bindings.get(&name).cloned() {
return self.upvarify(&ribs[i + 1..], def_like, span);
}
}
None
}
/// Searches the current set of local scopes for labels.
/// Stops after meeting a closure.
fn search_label(&self, name: Name) -> Option<DefLike> {
for rib in self.label_ribs.iter().rev() {
match rib.kind {
NormalRibKind => {
// Continue
}
_ => {
// Do not resolve labels across function boundary
return None
}
}
let result = rib.bindings.get(&name).cloned();
if result.is_some() {
return result
}
}
None
}
fn resolve_crate(&mut self, krate: &ast::Crate) {
debug!("(resolving crate) starting");
visit::walk_crate(self, krate);
}
fn check_if_primitive_type_name(&self, name: Name, span: Span) {
if let Some(_) = self.primitive_type_table.primitive_types.get(&name) {
span_err!(self.session, span, E0317,
"user-defined types or type parameters cannot shadow the primitive types");
}
}
fn resolve_item(&mut self, item: &Item) {
let name = item.ident.name;
debug!("(resolving item) resolving {}",
name);
match item.node {
ItemEnum(_, ref generics) |
ItemTy(_, ref generics) |
ItemStruct(_, ref generics) => {
self.check_if_primitive_type_name(name, item.span);
self.with_type_parameter_rib(HasTypeParameters(generics,
TypeSpace,
ItemRibKind),
|this| visit::walk_item(this, item));
}
ItemFn(_, _, _, _, ref generics, _) => {
self.with_type_parameter_rib(HasTypeParameters(generics,
FnSpace,
ItemRibKind),
|this| visit::walk_item(this, item));
}
ItemDefaultImpl(_, ref trait_ref) => {
self.with_optional_trait_ref(Some(trait_ref), |_, _| {});
}
ItemImpl(_,
_,
ref generics,
ref opt_trait_ref,
ref self_type,
ref impl_items) => {
self.resolve_implementation(generics,
opt_trait_ref,
&**self_type,
item.id,
&impl_items[..]);
}
ItemTrait(_, ref generics, ref bounds, ref trait_items) => {
self.check_if_primitive_type_name(name, item.span);
// Create a new rib for the trait-wide type parameters.
self.with_type_parameter_rib(HasTypeParameters(generics,
TypeSpace,
ItemRibKind),
|this| {
this.with_self_rib(DefSelfTy(Some(local_def(item.id)), None), |this| {
this.visit_generics(generics);
visit::walk_ty_param_bounds_helper(this, bounds);
for trait_item in trait_items {
match trait_item.node {
ast::ConstTraitItem(_, ref default) => {
// Only impose the restrictions of
// ConstRibKind if there's an actual constant
// expression in a provided default.
if default.is_some() {
this.with_constant_rib(|this| {
visit::walk_trait_item(this, trait_item)
});
} else {
visit::walk_trait_item(this, trait_item)
}
}
ast::MethodTraitItem(ref sig, _) => {
let type_parameters =
HasTypeParameters(&sig.generics,
FnSpace,
MethodRibKind);
this.with_type_parameter_rib(type_parameters, |this| {
visit::walk_trait_item(this, trait_item)
});
}
ast::TypeTraitItem(..) => {
this.check_if_primitive_type_name(trait_item.ident.name,
trait_item.span);
this.with_type_parameter_rib(NoTypeParameters, |this| {
visit::walk_trait_item(this, trait_item)
});
}
};
}
});
});
}
ItemMod(_) | ItemForeignMod(_) => {
self.with_scope(Some(name), |this| {
visit::walk_item(this, item);
});
}
ItemConst(..) | ItemStatic(..) => {
self.with_constant_rib(|this| {
visit::walk_item(this, item);
});
}
ItemUse(ref view_path) => {
// check for imports shadowing primitive types
if let ast::ViewPathSimple(ident, _) = view_path.node {
match self.def_map.borrow().get(&item.id).map(|d| d.full_def()) {
Some(DefTy(..)) | Some(DefStruct(..)) | Some(DefTrait(..)) | None => {
self.check_if_primitive_type_name(ident.name, item.span);
}
_ => {}
}
}
}
ItemExternCrate(_) | ItemMac(..) => {
// do nothing, these are just around to be encoded
}
}
}
fn with_type_parameter_rib<F>(&mut self, type_parameters: TypeParameters, f: F) where
F: FnOnce(&mut Resolver),
{
match type_parameters {
HasTypeParameters(generics, space, rib_kind) => {
let mut function_type_rib = Rib::new(rib_kind);
let mut seen_bindings = HashSet::new();
for (index, type_parameter) in generics.ty_params.iter().enumerate() {
let name = type_parameter.ident.name;
debug!("with_type_parameter_rib: {}", type_parameter.id);
if seen_bindings.contains(&name) {
resolve_error(self,
type_parameter.span,
ResolutionError::NameAlreadyUsedInTypeParameterList(
name)
);
}
seen_bindings.insert(name);
// plain insert (no renaming)
function_type_rib.bindings.insert(name,
DlDef(DefTyParam(space,
index as u32,
local_def(type_parameter.id),
name)));
}
self.type_ribs.push(function_type_rib);
}
NoTypeParameters => {
// Nothing to do.
}
}
f(self);
match type_parameters {
HasTypeParameters(..) => { self.type_ribs.pop(); }
NoTypeParameters => { }
}
}
fn with_label_rib<F>(&mut self, f: F) where
F: FnOnce(&mut Resolver),
{
self.label_ribs.push(Rib::new(NormalRibKind));
f(self);
self.label_ribs.pop();
}
fn with_constant_rib<F>(&mut self, f: F) where
F: FnOnce(&mut Resolver),
{
self.value_ribs.push(Rib::new(ConstantItemRibKind));
self.type_ribs.push(Rib::new(ConstantItemRibKind));
f(self);
self.type_ribs.pop();
self.value_ribs.pop();
}
fn resolve_function(&mut self,
rib_kind: RibKind,
declaration: &FnDecl,
block: &Block) {
// Create a value rib for the function.
self.value_ribs.push(Rib::new(rib_kind));
// Create a label rib for the function.
self.label_ribs.push(Rib::new(rib_kind));
// Add each argument to the rib.
let mut bindings_list = HashMap::new();
for argument in &declaration.inputs {
self.resolve_pattern(&*argument.pat,
ArgumentIrrefutableMode,
&mut bindings_list);
self.visit_ty(&*argument.ty);
debug!("(resolving function) recorded argument");
}
visit::walk_fn_ret_ty(self, &declaration.output);
// Resolve the function body.
self.visit_block(&*block);
debug!("(resolving function) leaving function");
self.label_ribs.pop();
self.value_ribs.pop();
}
fn resolve_trait_reference(&mut self,
id: NodeId,
trait_path: &Path,
path_depth: usize)
-> Result<PathResolution, ()> {
if let Some(path_res) = self.resolve_path(id, trait_path, path_depth, TypeNS, true) {
if let DefTrait(_) = path_res.base_def {
debug!("(resolving trait) found trait def: {:?}", path_res);
Ok(path_res)
} else {
resolve_error(self,
trait_path.span,
ResolutionError::IsNotATrait(&*path_names_to_string(trait_path,
path_depth))
);
// If it's a typedef, give a note
if let DefTy(..) = path_res.base_def {
self.session.span_note(trait_path.span,
"`type` aliases cannot be used for traits");
}
Err(())
}
} else {
resolve_error(self,
trait_path.span,
ResolutionError::UndeclaredTraitName(
&*path_names_to_string(trait_path, path_depth))
);
Err(())
}
}
fn resolve_generics(&mut self, generics: &Generics) {
for type_parameter in generics.ty_params.iter() {
self.check_if_primitive_type_name(type_parameter.ident.name, type_parameter.span);
}
for predicate in &generics.where_clause.predicates {
match predicate {
&ast::WherePredicate::BoundPredicate(_) |
&ast::WherePredicate::RegionPredicate(_) => {}
&ast::WherePredicate::EqPredicate(ref eq_pred) => {
let path_res = self.resolve_path(eq_pred.id, &eq_pred.path, 0, TypeNS, true);
if let Some(PathResolution { base_def: DefTyParam(..), .. }) = path_res {
self.record_def(eq_pred.id, path_res.unwrap());
} else {
resolve_error(self,
eq_pred.span,
ResolutionError::UndeclaredAssociatedType);
}
}
}
}
visit::walk_generics(self, generics);
}
fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
where F: FnOnce(&mut Resolver) -> 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, F>(&mut self,
opt_trait_ref: Option<&TraitRef>,
f: F)
-> T
where F: FnOnce(&mut Resolver, Option<DefId>) -> T
{
let mut new_val = None;
let mut new_id = None;
if let Some(trait_ref) = opt_trait_ref {
if let Ok(path_res) = self.resolve_trait_reference(trait_ref.ref_id,
&trait_ref.path, 0) {
assert!(path_res.depth == 0);
self.record_def(trait_ref.ref_id, path_res);
new_val = Some((path_res.base_def.def_id(), trait_ref.clone()));
new_id = Some(path_res.base_def.def_id());
}
visit::walk_trait_ref(self, trait_ref);
}
let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
let result = f(self, new_id);
self.current_trait_ref = original_trait_ref;
result
}
fn with_self_rib<F>(&mut self, self_def: Def, f: F)
where F: FnOnce(&mut Resolver)
{
let mut self_type_rib = Rib::new(NormalRibKind);
// plain insert (no renaming, types are not currently hygienic....)
let name = special_names::type_self;
self_type_rib.bindings.insert(name, DlDef(self_def));
self.type_ribs.push(self_type_rib);
f(self);
self.type_ribs.pop();
}
fn resolve_implementation(&mut self,
generics: &Generics,
opt_trait_reference: &Option<TraitRef>,
self_type: &Ty,
item_id: NodeId,
impl_items: &[P<ImplItem>]) {
// If applicable, create a rib for the type parameters.
self.with_type_parameter_rib(HasTypeParameters(generics,
TypeSpace,
ItemRibKind),
|this| {
// Resolve the type parameters.
this.visit_generics(generics);
// Resolve the trait reference, if necessary.
this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
// Resolve the self type.
this.visit_ty(self_type);
this.with_self_rib(DefSelfTy(trait_id, Some((item_id, self_type.id))), |this| {
this.with_current_self_type(self_type, |this| {
for impl_item in impl_items {
match impl_item.node {
ConstImplItem(..) => {
// If this is a trait impl, ensure the const
// exists in trait
this.check_trait_item(impl_item.ident.name,
impl_item.span,
|n, s| ResolutionError::ConstNotMemberOfTrait(n, s));
this.with_constant_rib(|this| {
visit::walk_impl_item(this, impl_item);
});
}
MethodImplItem(ref sig, _) => {
// If this is a trait impl, ensure the method
// exists in trait
this.check_trait_item(impl_item.ident.name,
impl_item.span,
|n, s| ResolutionError::MethodNotMemberOfTrait(n, s));
// We also need a new scope for the method-
// specific type parameters.
let type_parameters =
HasTypeParameters(&sig.generics,
FnSpace,
MethodRibKind);
this.with_type_parameter_rib(type_parameters, |this| {
visit::walk_impl_item(this, impl_item);
});
}
TypeImplItem(ref ty) => {
// If this is a trait impl, ensure the type
// exists in trait
this.check_trait_item(impl_item.ident.name,
impl_item.span,
|n, s| ResolutionError::TypeNotMemberOfTrait(n, s));
this.visit_ty(ty);
}
ast::MacImplItem(_) => {}
}
}
});
});
});
});
}
fn check_trait_item<F>(&self, name: Name, span: Span, err: F)
where F: FnOnce(Name, &str) -> ResolutionError {
// If there is a TraitRef in scope for an impl, then the method must be in the trait.
if let Some((did, ref trait_ref)) = self.current_trait_ref {
if !self.trait_item_map.contains_key(&(name, did)) {
let path_str = path_names_to_string(&trait_ref.path, 0);
resolve_error(self,
span,
err(name, &*path_str));
}
}
}
fn resolve_local(&mut self, local: &Local) {
// Resolve the type.
visit::walk_ty_opt(self, &local.ty);
// Resolve the initializer.
visit::walk_expr_opt(self, &local.init);
// Resolve the pattern.
self.resolve_pattern(&*local.pat,
LocalIrrefutableMode,
&mut HashMap::new());
}
// 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, path1| {
let name = mtwt::resolve(path1.node);
result.insert(name, BindingInfo {
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.is_empty() {
return
}
let map_0 = self.binding_mode_map(&*arm.pats[0]);
for (i, p) in arm.pats.iter().enumerate() {
let map_i = self.binding_mode_map(&**p);
for (&key, &binding_0) in &map_0 {
match map_i.get(&key) {
None => {
resolve_error(self,
p.span,
ResolutionError::VariableNotBoundInPattern(key,
i + 1));
}
Some(binding_i) => {
if binding_0.binding_mode != binding_i.binding_mode {
resolve_error(self,
binding_i.span,
ResolutionError::VariableBoundWithDifferentMode(key,
i + 1)
);
}
}
}
}
for (&key, &binding) in &map_i {
if !map_0.contains_key(&key) {
resolve_error(self,
binding.span,
ResolutionError::VariableNotBoundInParentPattern(key,
i + 1));
}
}
}
}
fn resolve_arm(&mut self, arm: &Arm) {
self.value_ribs.push(Rib::new(NormalRibKind));
let mut bindings_list = HashMap::new();
for pattern in &arm.pats {
self.resolve_pattern(&**pattern, RefutableMode, &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.visit_expr(&*arm.body);
self.value_ribs.pop();
}
fn resolve_block(&mut self, block: &Block) {
debug!("(resolving block) entering block");
self.value_ribs.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().get(&block.id) {
None => { /* Nothing to do. */ }
Some(anonymous_module) => {
debug!("(resolving block) found anonymous module, moving \
down");
self.current_module = anonymous_module.clone();
}
}
// Check for imports appearing after non-item statements.
let mut found_non_item = false;
for statement in &block.stmts {
if let ast::StmtDecl(ref declaration, _) = statement.node {
if let ast::DeclItem(ref i) = declaration.node {
match i.node {
ItemExternCrate(_) | ItemUse(_) if found_non_item => {
span_err!(self.session, i.span, E0154,
"imports are not allowed after non-item statements");
}
_ => {}
}
} else {
found_non_item = true
}
} else {
found_non_item = true;
}
}
// Descend into the block.
visit::walk_block(self, block);
// Move back up.
self.current_module = orig_module;
self.value_ribs.pop();
debug!("(resolving block) leaving block");
}
fn resolve_type(&mut self, ty: &Ty) {
match ty.node {
TyPath(ref maybe_qself, ref path) => {
let resolution =
match self.resolve_possibly_assoc_item(ty.id,
maybe_qself.as_ref(),
path,
TypeNS,
true) {
// `<T>::a::b::c` is resolved by typeck alone.
TypecheckRequired => {
// Resolve embedded types.
visit::walk_ty(self, ty);
return;
}
ResolveAttempt(resolution) => resolution,
};
// This is a path in the type namespace. Walk through scopes
// looking for it.
match resolution {
Some(def) => {
// Write the result into the def map.
debug!("(resolving type) writing resolution for `{}` \
(id {}) = {:?}",
path_names_to_string(path, 0),
ty.id, def);
self.record_def(ty.id, def);
}
None => {
// Keep reporting some errors even if they're ignored above.
self.resolve_path(ty.id, path, 0, TypeNS, true);
let kind = if maybe_qself.is_some() {
"associated type"
} else {
"type name"
};
let self_type_name = special_idents::type_self.name;
let is_invalid_self_type_name =
path.segments.len() > 0 &&
maybe_qself.is_none() &&
path.segments[0].identifier.name == self_type_name;
if is_invalid_self_type_name {
resolve_error(self,
ty.span,
ResolutionError::SelfUsedOutsideImplOrTrait);
} else {
resolve_error(self,
ty.span,
ResolutionError::UseOfUndeclared(
kind,
&*path_names_to_string(path,
0))
);
}
}
}
}
_ => {}
}
// 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
bindings_list: &mut HashMap<Name, NodeId>) {
let pat_id = pattern.id;
walk_pat(pattern, |pattern| {
match pattern.node {
PatIdent(binding_mode, ref path1, ref at_rhs) => {
// The meaning of PatIdent 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
// and the LHS of @-patterns), matching such a value is
// simply disallowed (since it's rarely what you want).
let const_ok = mode == RefutableMode && at_rhs.is_none();
let ident = path1.node;
let renamed = mtwt::resolve(ident);
match self.resolve_bare_identifier_pattern(ident.name, pattern.span) {
FoundStructOrEnumVariant(def, lp) if const_ok => {
debug!("(resolving pattern) resolving `{}` to \
struct or enum variant",
renamed);
self.enforce_default_binding_mode(
pattern,
binding_mode,
"an enum variant");
self.record_def(pattern.id, PathResolution {
base_def: def,
last_private: lp,
depth: 0
});
}
FoundStructOrEnumVariant(..) => {
resolve_error(
self,
pattern.span,
ResolutionError::DeclarationShadowsEnumVariantOrUnitLikeStruct(
renamed)
);
}
FoundConst(def, lp) if const_ok => {
debug!("(resolving pattern) resolving `{}` to \
constant",
renamed);
self.enforce_default_binding_mode(
pattern,
binding_mode,
"a constant");
self.record_def(pattern.id, PathResolution {
base_def: def,
last_private: lp,
depth: 0
});
}
FoundConst(..) => {
resolve_error(
self,
pattern.span,
ResolutionError::OnlyIrrefutablePatternsAllowedHere
);
}
BareIdentifierPatternUnresolved => {
debug!("(resolving pattern) binding `{}`",
renamed);
let def = DefLocal(pattern.id);
// Record the definition so that later passes
// will be able to distinguish variants from
// locals in patterns.
self.record_def(pattern.id, PathResolution {
base_def: def,
last_private: LastMod(AllPublic),
depth: 0
});
// 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.)
if !bindings_list.contains_key(&renamed) {
let this = &mut *self;
let last_rib = this.value_ribs.last_mut().unwrap();
last_rib.bindings.insert(renamed, DlDef(def));
bindings_list.insert(renamed, pat_id);
} else if mode == ArgumentIrrefutableMode &&
bindings_list.contains_key(&renamed) {
// Forbid duplicate bindings in the same
// parameter list.
resolve_error(
self,
pattern.span,
ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
&ident.name.as_str())
);
} else if bindings_list.get(&renamed) ==
Some(&pat_id) {
// Then this is a duplicate variable in the
// same disjunction, which is an error.
resolve_error(
self,
pattern.span,
ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
&ident.name.as_str())
);
}
// Else, not bound in the same pattern: do
// nothing.
}
}
}
PatEnum(ref path, _) => {
// This must be an enum variant, struct or const.
let resolution =
match self.resolve_possibly_assoc_item(pat_id, None,
path, ValueNS,
false) {
// The below shouldn't happen because all
// qualified paths should be in PatQPath.
TypecheckRequired =>
self.session.span_bug(
path.span,
"resolve_possibly_assoc_item claimed
that a path in PatEnum requires typecheck
to resolve, but qualified paths should be
PatQPath"),
ResolveAttempt(resolution) => resolution,
};
if let Some(path_res) = resolution {
match path_res.base_def {
DefVariant(..) | DefStruct(..) | DefConst(..) => {
self.record_def(pattern.id, path_res);
}
DefStatic(..) => {
resolve_error(&self,
path.span,
ResolutionError::StaticVariableReference);
}
_ => {
// If anything ends up here entirely resolved,
// it's an error. If anything ends up here
// partially resolved, that's OK, because it may
// be a `T::CONST` that typeck will resolve.
if path_res.depth == 0 {
resolve_error(
self,
path.span,
ResolutionError::NotAnEnumVariantStructOrConst(
&path.segments
.last()
.unwrap()
.identifier
.name
.as_str())
);
} else {
let const_name = path.segments.last().unwrap()
.identifier.name;
let traits = self.get_traits_containing_item(const_name);
self.trait_map.insert(pattern.id, traits);
self.record_def(pattern.id, path_res);
}
}
}
} else {
resolve_error(
self,
path.span,
ResolutionError::UnresolvedEnumVariantStructOrConst(
&path.segments.last().unwrap().identifier.name.as_str())
);
}
visit::walk_path(self, path);
}
PatQPath(ref qself, ref path) => {
// Associated constants only.
let resolution =
match self.resolve_possibly_assoc_item(pat_id, Some(qself),
path, ValueNS,
false) {
TypecheckRequired => {
// All `<T>::CONST` should end up here, and will
// require use of the trait map to resolve
// during typechecking.
let const_name = path.segments.last().unwrap()
.identifier.name;
let traits = self.get_traits_containing_item(const_name);
self.trait_map.insert(pattern.id, traits);
visit::walk_pat(self, pattern);
return true;
}
ResolveAttempt(resolution) => resolution,
};
if let Some(path_res) = resolution {
match path_res.base_def {
// All `<T as Trait>::CONST` should end up here, and
// have the trait already selected.
DefAssociatedConst(..) => {
self.record_def(pattern.id, path_res);
}
_ => {
resolve_error(
self,
path.span,
ResolutionError::NotAnAssociatedConst(
&path.segments.last().unwrap().identifier.name.as_str()
)
);
}
}
} else {
resolve_error(
self,
path.span,
ResolutionError::UnresolvedAssociatedConst(
&path.segments.last().unwrap().identifier.name.as_str()
)
);
}
visit::walk_pat(self, pattern);
}
PatStruct(ref path, _, _) => {
match self.resolve_path(pat_id, path, 0, TypeNS, false) {
Some(definition) => {
self.record_def(pattern.id, definition);
}
result => {
debug!("(resolving pattern) didn't find struct \
def: {:?}", result);
resolve_error(
self,
path.span,
ResolutionError::DoesNotNameAStruct(
&*path_names_to_string(path, 0))
);
}
}
visit::walk_path(self, path);
}
PatLit(_) | PatRange(..) => {
visit::walk_pat(self, pattern);
}
_ => {
// Nothing to do.
}
}
true
});
}
fn resolve_bare_identifier_pattern(&mut self, name: Name, span: Span)
-> 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 {:?}",
name,
target.bindings.value_def.borrow());
match *target.bindings.value_def.borrow() {
None => {
panic!("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 @ DefConst(..) | def @ DefAssociatedConst(..) => {
return FoundConst(def, LastMod(AllPublic));
}
DefStatic(..) => {
resolve_error(self,
span,
ResolutionError::StaticVariableReference);
return BareIdentifierPatternUnresolved;
}
_ => {
return BareIdentifierPatternUnresolved;
}
}
}
}
}
Indeterminate => {
panic!("unexpected indeterminate result");
}
Failed(err) => {
match err {
Some((span, msg)) => {
resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
}
None => ()
}
debug!("(resolve bare identifier pattern) failed to find {}",
name);
return BareIdentifierPatternUnresolved;
}
}
}
/// Handles paths that may refer to associated items
fn resolve_possibly_assoc_item(&mut self,
id: NodeId,
maybe_qself: Option<&ast::QSelf>,
path: &Path,
namespace: Namespace,
check_ribs: bool)
-> AssocItemResolveResult
{
let max_assoc_types;
match maybe_qself {
Some(qself) => {
if qself.position == 0 {
return TypecheckRequired;
}
max_assoc_types = path.segments.len() - qself.position;
// Make sure the trait is valid.
let _ = self.resolve_trait_reference(id, path, max_assoc_types);
}
None => {
max_assoc_types = path.segments.len();
}
}
let mut resolution = self.with_no_errors(|this| {
this.resolve_path(id, path, 0, namespace, check_ribs)
});
for depth in 1..max_assoc_types {
if resolution.is_some() {
break;
}
self.with_no_errors(|this| {
resolution = this.resolve_path(id, path, depth,
TypeNS, true);
});
}
if let Some(DefMod(_)) = resolution.map(|r| r.base_def) {
// A module is not a valid type or value.
resolution = None;
}
ResolveAttempt(resolution)
}
/// If `check_ribs` is true, checks the local definitions first; i.e.
/// doesn't skip straight to the containing module.
/// Skips `path_depth` trailing segments, which is also reflected in the
/// returned value. See `middle::def::PathResolution` for more info.
fn resolve_path(&mut self,
id: NodeId,
path: &Path,
path_depth: usize,
namespace: Namespace,
check_ribs: bool) -> Option<PathResolution> {
let span = path.span;
let segments = &path.segments[..path.segments.len()-path_depth];
let mk_res = |(def, lp)| PathResolution::new(def, lp, path_depth);
if path.global {
let def = self.resolve_crate_relative_path(span, segments, namespace);
return def.map(mk_res);
}
// Try to find a path to an item in a module.
let unqualified_def =
self.resolve_identifier(segments.last().unwrap().identifier,
namespace,
check_ribs,
span);
if segments.len() <= 1 {
return unqualified_def.map(mk_res);
}
let def = self.resolve_module_relative_path(span, segments, namespace);
match (def, unqualified_def) {
(Some((ref d, _)), Some((ref ud, _))) if *d == *ud => {
self.session
.add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
id, span,
"unnecessary qualification".to_string());
}
_ => {}
}
def.map(mk_res)
}
// Resolve a single identifier.
fn resolve_identifier(&mut self,
identifier: Ident,
namespace: Namespace,
check_ribs: bool,
span: Span)
-> Option<(Def, LastPrivate)> {
// First, check to see whether the name is a primitive type.
if namespace == TypeNS {
if let Some(&prim_ty) = self.primitive_type_table
.primitive_types
.get(&identifier.name) {
return Some((DefPrimTy(prim_ty), LastMod(AllPublic)));
}
}
if check_ribs {
if let Some(def) = self.resolve_identifier_in_local_ribs(identifier,
namespace,
span) {
return Some((def, LastMod(AllPublic)));
}
}
self.resolve_item_by_name_in_lexical_scope(identifier.name, 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.
build_reduced_graph::populate_module_if_necessary(self, &containing_module);
match containing_module.children.borrow().get(&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.def_id()))
};
return ChildNameDefinition(def, lp);
}
None => {}
}
}
None => {}
}
// Next, search import resolutions.
match containing_module.import_resolutions.borrow().get(&name) {
Some(import_resolution) if import_resolution.is_public => {
if let Some(target) = (*import_resolution).target_for_namespace(namespace) {
match target.bindings.def_for_namespace(namespace) {
Some(def) => {
// Found it.
let id = import_resolution.id(namespace);
// track imports and extern crates as well
self.used_imports.insert((id, namespace));
self.record_import_use(id, name);
match target.target_module.def_id.get() {
Some(DefId{krate: kid, ..}) => {
self.used_crates.insert(kid);
},
_ => {}
}
return ImportNameDefinition(def, LastMod(AllPublic));
}
None => {
// This can happen with external impls, due to
// the imperfect way we read the metadata.
}
}
}
}
Some(..) | None => {} // Continue.
}
// Finally, search through external children.
if namespace == TypeNS {
if let Some(module) = containing_module.external_module_children.borrow()
.get(&name).cloned() {
if let Some(def_id) = module.def_id.get() {
// track used crates
self.used_crates.insert(def_id.krate);
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,
span: Span,
segments: &[ast::PathSegment],
namespace: Namespace)
-> Option<(Def, LastPrivate)> {
let module_path = segments.split_last().unwrap().1.iter()
.map(|ps| ps.identifier.name)
.collect::<Vec<_>>();
let containing_module;
let last_private;
let current_module = self.current_module.clone();
match self.resolve_module_path(current_module,
&module_path[..],
UseLexicalScope,
span,
PathSearch) {
Failed(err) => {
let (span, msg) = match err {
Some((span, msg)) => (span, msg),
None => {
let msg = format!("Use of undeclared type or module `{}`",
names_to_string(&module_path));
(span, msg)
}
};
resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
return None;
}
Indeterminate => panic!("indeterminate unexpected"),
Success((resulting_module, resulting_last_private)) => {
containing_module = resulting_module;
last_private = resulting_last_private;
}
}
let name = segments.last().unwrap().identifier.name;
let def = match self.resolve_definition_of_name_in_module(containing_module.clone(),
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))
}
};
if let Some(DefId{krate: kid, ..}) = containing_module.def_id.get() {
self.used_crates.insert(kid);
}
return Some(def);
}
/// Invariant: This must be called only during main resolution, not during
/// import resolution.
fn resolve_crate_relative_path(&mut self,
span: Span,
segments: &[ast::PathSegment],
namespace: Namespace)
-> Option<(Def, LastPrivate)> {
let module_path = segments.split_last().unwrap().1.iter()
.map(|ps| ps.identifier.name)
.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[..],
0,
span,
PathSearch,
LastMod(AllPublic)) {
Failed(err) => {
let (span, msg) = match err {
Some((span, msg)) => (span, msg),
None => {
let msg = format!("Use of undeclared module `::{}`",
names_to_string(&module_path[..]));
(span, msg)
}
};
resolve_error(self, span, ResolutionError::FailedToResolve(&*msg));
return None;
}
Indeterminate => {
panic!("indeterminate unexpected");
}
Success((resulting_module, resulting_last_private)) => {
containing_module = resulting_module;
last_private = resulting_last_private;
}
}
let name = 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, renamed, span)
}
TypeNS => {
let name = ident.name;
self.search_ribs(&self.type_ribs, name, span)
}
};
match search_result {
Some(DlDef(def)) => {
debug!("(resolving path in local ribs) resolved `{}` to local: {:?}",
ident,
def);
Some(def)
}
Some(DlField) | Some(DlImpl(_)) | None => {
None
}
}
}
fn resolve_item_by_name_in_lexical_scope(&mut self,
name: Name,
namespace: Namespace)
-> Option<(Def, LastPrivate)> {
// Check the items.
let module = self.current_module.clone();
match self.resolve_item_in_lexical_scope(module,
name,
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...",
name);
return None;
}
Some(def) => {
debug!("(resolving item path in lexical scope) \
resolved `{}` to item",
name);
// 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 => {
panic!("unexpected indeterminate result");
}
Failed(err) => {
debug!("(resolving item path by identifier in lexical scope) \
failed to resolve {}", name);
if let Some((span, msg)) = err {
resolve_error(self, span, ResolutionError::FailedToResolve(&*msg))
}
return None;
}
}
}
fn with_no_errors<T, F>(&mut self, f: F) -> T where
F: FnOnce(&mut Resolver) -> T,
{
self.emit_errors = false;
let rs = f(self);
self.emit_errors = true;
rs
}
fn find_fallback_in_self_type(&mut self, name: Name) -> FallbackSuggestion {
fn extract_path_and_node_id(t: &Ty, allow: FallbackChecks)
-> Option<(Path, NodeId, FallbackChecks)> {
match t.node {
TyPath(None, ref path) => Some((path.clone(), t.id, allow)),
TyPtr(ref mut_ty) => extract_path_and_node_id(&*mut_ty.ty, OnlyTraitAndStatics),
TyRptr(_, ref 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, name_path: &[ast::Name])
-> Option<Rc<Module>> {
let root = this.current_module.clone();
let last_name = name_path.last().unwrap();
if name_path.len() == 1 {
match this.primitive_type_table.primitive_types.get(last_name) {
Some(_) => None,
None => {
match this.current_module.children.borrow().get(last_name) {
Some(child) => child.get_module_if_available(),
None => None
}
}
}
} else {
match this.resolve_module_path(root,
&name_path[..],
UseLexicalScope,
span,
PathSearch) {
Success((module, _)) => Some(module),
_ => None
}
}
}
fn is_static_method(this: &Resolver, did: DefId) -> bool {
if did.krate == ast::LOCAL_CRATE {
let sig = match this.ast_map.get(did.node) {
ast_map::NodeTraitItem(trait_item) => match trait_item.node {
ast::MethodTraitItem(ref sig, _) => sig,
_ => return false
},
ast_map::NodeImplItem(impl_item) => match impl_item.node {
ast::MethodImplItem(ref sig, _) => sig,
_ => return false
},
_ => return false
};
sig.explicit_self.node == ast::SelfStatic
} else {
csearch::is_static_method(&this.session.cstore, did)
}
}
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().get(&node_id).map(|d| d.full_def()) {
Some(DefTy(did, _)) |
Some(DefStruct(did)) |
Some(DefVariant(_, did, _)) => match self.structs.get(&did) {
None => {}
Some(fields) => {
if fields.iter().any(|&field_name| name == field_name) {
return Field;
}
}
},
_ => {} // Self type didn't resolve properly
}
}
let name_path = path.segments.iter().map(|seg| seg.identifier.name).collect::<Vec<_>>();
// Look for a method in the current self type's impl module.
if let Some(module) = get_module(self, path.span, &name_path) {
if let Some(binding) = module.children.borrow().get(&name) {
if let Some(DefMethod(did, _)) = binding.def_for_namespace(ValueNS) {
if is_static_method(self, did) {
return StaticMethod(path_names_to_string(&path, 0))
}
if self.current_trait_ref.is_some() {
return TraitItem;
} else if allowed == Everything {
return Method;
}
}
}
}
// Look for a method in the current trait.
if let Some((trait_did, ref trait_ref)) = self.current_trait_ref {
if let Some(&did) = self.trait_item_map.get(&(name, trait_did)) {
if is_static_method(self, did) {
return TraitMethod(path_names_to_string(&trait_ref.path, 0));
} else {
return TraitItem;
}
}
}
NoSuggestion
}
fn find_best_match_for_name(&mut self, name: &str) -> Option<String> {
let mut maybes: Vec<token::InternedString> = Vec::new();
let mut values: Vec<usize> = Vec::new();
for rib in self.value_ribs.iter().rev() {
for (&k, _) in &rib.bindings {
maybes.push(k.as_str());
values.push(usize::MAX);
}
}
let mut smallest = 0;
for (i, other) in maybes.iter().enumerate() {
values[i] = lev_distance(name, &other);
if values[i] <= values[smallest] {
smallest = i;
}
}
// As a loose rule to avoid obviously incorrect suggestions, clamp the
// maximum edit distance we will accept for a suggestion to one third of
// the typo'd name's length.
let max_distance = std::cmp::max(name.len(), 3) / 3;
if !values.is_empty() &&
values[smallest] <= max_distance &&
name != &maybes[smallest][..] {
Some(maybes[smallest].to_string())
} 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 {
ExprPath(ref maybe_qself, ref path) => {
let resolution =
match self.resolve_possibly_assoc_item(expr.id,
maybe_qself.as_ref(),
path,
ValueNS,
true) {
// `<T>::a::b::c` is resolved by typeck alone.
TypecheckRequired => {
let method_name = path.segments.last().unwrap().identifier.name;
let traits = self.get_traits_containing_item(method_name);
self.trait_map.insert(expr.id, traits);
visit::walk_expr(self, expr);
return;
}
ResolveAttempt(resolution) => resolution,
};
// This is a local path in the value namespace. Walk through
// scopes looking for it.
if let Some(path_res) = resolution {
// Check if struct variant
if let DefVariant(_, _, true) = path_res.base_def {
let path_name = path_names_to_string(path, 0);
resolve_error(self,
expr.span,
ResolutionError::StructVariantUsedAsFunction(&*path_name));
let msg = format!("did you mean to write: \
`{} {{ /* fields */ }}`?",
path_name);
if self.emit_errors {
self.session.fileline_help(expr.span, &msg);
} else {
self.session.span_help(expr.span, &msg);
}
} else {
// Write the result into the def map.
debug!("(resolving expr) resolved `{}`",
path_names_to_string(path, 0));
// Partial resolutions will need the set of traits in scope,
// so they can be completed during typeck.
if path_res.depth != 0 {
let method_name = path.segments.last().unwrap().identifier.name;
let traits = self.get_traits_containing_item(method_name);
self.trait_map.insert(expr.id, traits);
}
self.record_def(expr.id, path_res);
}
} else {
// 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.)
let path_name = path_names_to_string(path, 0);
let type_res = self.with_no_errors(|this| {
this.resolve_path(expr.id, path, 0, TypeNS, false)
});
match type_res.map(|r| r.base_def) {
Some(DefTy(struct_id, _))
if self.structs.contains_key(&struct_id) => {
resolve_error(
self,
expr.span,
ResolutionError::StructVariantUsedAsFunction(
&*path_name)
);
let msg = format!("did you mean to write: \
`{} {{ /* fields */ }}`?",
path_name);
if self.emit_errors {
self.session.fileline_help(expr.span, &msg);
} else {
self.session.span_help(expr.span, &msg);
}
}
_ => {
// Keep reporting some errors even if they're ignored above.
self.resolve_path(expr.id, path, 0, ValueNS, true);
let mut method_scope = false;
self.value_ribs.iter().rev().all(|rib| {
method_scope = match rib.kind {
MethodRibKind => true,
ItemRibKind | ConstantItemRibKind => false,
_ => return true, // Keep advancing
};
false // Stop advancing
});
if method_scope && special_names::self_ == path_name {
resolve_error(
self,
expr.span,
ResolutionError::SelfNotAvailableInStaticMethod
);
} else {
let last_name = path.segments.last().unwrap().identifier.name;
let mut msg = match self.find_fallback_in_self_type(last_name) {
NoSuggestion => {
// limit search to 5 to reduce the number
// of stupid suggestions
self.find_best_match_for_name(&path_name)
.map_or("".to_string(),
|x| format!("`{}`", x))
}
Field => format!("`self.{}`", path_name),
Method |
TraitItem =>
format!("to call `self.{}`", path_name),
TraitMethod(path_str) |
StaticMethod(path_str) =>
format!("to call `{}::{}`", path_str, path_name)
};
if !msg.is_empty() {
msg = format!(". Did you mean {}?", msg)
}
resolve_error(self,
expr.span,
ResolutionError::UnresolvedName(&*path_name,
&*msg));
}
}
}
}
visit::walk_expr(self, expr);
}
ExprStruct(ref path, _, _) => {
// Resolve the path to the structure it goes to. We don't
// check to ensure that the path is actually a structure; that
// is checked later during typeck.
match self.resolve_path(expr.id, path, 0, TypeNS, false) {
Some(definition) => self.record_def(expr.id, definition),
None => {
debug!("(resolving expression) didn't find struct def",);
resolve_error(self,
path.span,
ResolutionError::DoesNotNameAStruct(
&*path_names_to_string(path, 0))
);
}
}
visit::walk_expr(self, expr);
}
ExprLoop(_, Some(label)) | ExprWhile(_, _, Some(label)) => {
self.with_label_rib(|this| {
let def_like = DlDef(DefLabel(expr.id));
{
let rib = this.label_ribs.last_mut().unwrap();
let renamed = mtwt::resolve(label);
rib.bindings.insert(renamed, def_like);
}
visit::walk_expr(this, expr);
})
}
ExprBreak(Some(label)) | ExprAgain(Some(label)) => {
let renamed = mtwt::resolve(label);
match self.search_label(renamed) {
None => {
resolve_error(self,
expr.span,
ResolutionError::UndeclaredLabel(&label.name.as_str()))
}
Some(DlDef(def @ DefLabel(_))) => {
// Since this def is a label, it is never read.
self.record_def(expr.id, PathResolution {
base_def: def,
last_private: LastMod(AllPublic),
depth: 0
})
}
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.get_traits_containing_item(ident.node.name);
self.trait_map.insert(expr.id, traits);
}
ExprMethodCall(ident, _, _) => {
debug!("(recording candidate traits for expr) recording \
traits for {}",
expr.id);
let traits = self.get_traits_containing_item(ident.node.name);
self.trait_map.insert(expr.id, traits);
}
_ => {
// Nothing to do.
}
}
}
fn get_traits_containing_item(&mut self, name: Name) -> Vec<DefId> {
debug!("(getting traits containing item) looking for '{}'",
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,
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, _)) => {
if self.trait_item_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.
build_reduced_graph::populate_module_if_necessary(self, &search_module);
{
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 self.trait_item_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.trait_item_map.contains_key(&(name, did)) {
add_trait_info(&mut found_traits, did, name);
let id = import.type_id;
self.used_imports.insert((id, TypeNS));
let trait_name = self.get_trait_name(did);
self.record_import_use(id, trait_name);
if let Some(DefId{krate: kid, ..}) = target.target_module.def_id.get() {
self.used_crates.insert(kid);
}
}
}
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, resolution: PathResolution) {
debug!("(recording def) recording {:?} for {}", resolution, node_id);
assert!(match resolution.last_private {LastImport{..} => false, _ => true},
"Import should only be used for `use` directives");
if let Some(prev_res) = self.def_map.borrow_mut().insert(node_id, resolution) {
let span = self.ast_map.opt_span(node_id).unwrap_or(codemap::DUMMY_SP);
self.session.span_bug(span, &format!("path resolved multiple times \
({:?} before, {:?} now)",
prev_res, resolution));
}
}
fn enforce_default_binding_mode(&mut self,
pat: &Pat,
pat_binding_mode: BindingMode,
descr: &str) {
match pat_binding_mode {
BindByValue(_) => {}
BindByRef(..) => {
resolve_error(self,
pat.span,
ResolutionError::CannotUseRefBindingModeWith(descr));
}
}
}
//
// Diagnostics
//
// Diagnostics are not particularly efficient, because they're rarely
// hit.
//
#[allow(dead_code)] // useful for debugging
fn dump_module(&mut self, module_: Rc<Module>) {
debug!("Dump of module `{}`:", module_to_string(&*module_));
debug!("Children:");
build_reduced_graph::populate_module_if_necessary(self, &module_);
for (&name, _) in module_.children.borrow().iter() {
debug!("* {}", 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_string(); }
Some(_) => {
value_repr = " value:?".to_string();
// FIXME #4954
}
}
let type_repr;
match import_resolution.target_for_namespace(TypeNS) {
None => { type_repr = "".to_string(); }
Some(_) => {
type_repr = " type:?".to_string();
// FIXME #4954
}
}
debug!("* {}:{}{}", name, value_repr, type_repr);
}
}
}
fn names_to_string(names: &[Name]) -> String {
let mut first = true;
let mut result = String::new();
for name in names {
if first {
first = false
} else {
result.push_str("::")
}
result.push_str(&name.as_str());
};
result
}
fn path_names_to_string(path: &Path, depth: usize) -> String {
let names: Vec<ast::Name> = path.segments[..path.segments.len()-depth]
.iter()
.map(|seg| seg.identifier.name)
.collect();
names_to_string(&names[..])
}
/// A somewhat inefficient routine to obtain the name of a module.
fn module_to_string(module: &Module) -> String {
let mut names = Vec::new();
fn collect_mod(names: &mut Vec<ast::Name>, module: &Module) {
match module.parent_link {
NoParentLink => {}
ModuleParentLink(ref module, name) => {
names.push(name);
collect_mod(names, &*module.upgrade().unwrap());
}
BlockParentLink(ref module, _) => {
// danger, shouldn't be ident?
names.push(special_idents::opaque.name);
collect_mod(names, &*module.upgrade().unwrap());
}
}
}
collect_mod(&mut names, module);
if names.is_empty() {
return "???".to_string();
}
names_to_string(&names.into_iter().rev().collect::<Vec<ast::Name>>())
}
pub struct CrateMap {
pub def_map: DefMap,
pub freevars: RefCell<FreevarMap>,
pub export_map: ExportMap,
pub trait_map: TraitMap,
pub external_exports: ExternalExports,
pub glob_map: Option<GlobMap>
}
#[derive(PartialEq,Copy, Clone)]
pub enum MakeGlobMap {
Yes,
No
}
/// Entry point to crate resolution.
pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
ast_map: &'a ast_map::Map<'tcx>,
make_glob_map: MakeGlobMap)
-> CrateMap {
let krate = ast_map.krate();
let mut resolver = Resolver::new(session, ast_map, krate.span, make_glob_map);
build_reduced_graph::build_reduced_graph(&mut resolver, krate);
session.abort_if_errors();
resolve_imports::resolve_imports(&mut resolver);
session.abort_if_errors();
record_exports::record(&mut resolver);
session.abort_if_errors();
resolver.resolve_crate(krate);
session.abort_if_errors();
check_unused::check_crate(&mut resolver, krate);
CrateMap {
def_map: resolver.def_map,
freevars: resolver.freevars,
export_map: resolver.export_map,
trait_map: resolver.trait_map,
external_exports: resolver.external_exports,
glob_map: if resolver.make_glob_map {
Some(resolver.glob_map)
} else {
None
},
}
}
__build_diagnostic_array! { librustc_resolve, DIAGNOSTICS }
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