rust/src/librustc_resolve/build_reduced_graph.rs
2015-07-13 00:31:09 +02:00

998 lines
42 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Reduced graph building
//!
//! Here we build the "reduced graph": the graph of the module tree without
//! any imports resolved.
use DefModifiers;
use resolve_imports::ImportDirective;
use resolve_imports::ImportDirectiveSubclass::{self, SingleImport, GlobImport};
use resolve_imports::ImportResolution;
use Module;
use ModuleKind::*;
use Namespace::{TypeNS, ValueNS};
use NameBindings;
use {names_to_string, module_to_string};
use ParentLink::{self, ModuleParentLink, BlockParentLink};
use Resolver;
use resolve_imports::Shadowable;
use TypeNsDef;
use self::DuplicateCheckingMode::*;
use self::NamespaceError::*;
use rustc::metadata::csearch;
use rustc::metadata::decoder::{DefLike, DlDef, DlField, DlImpl};
use rustc::middle::def::*;
use syntax::ast::{Block, Crate};
use syntax::ast::{DeclItem, DefId};
use syntax::ast::{ForeignItem, ForeignItemFn, ForeignItemStatic};
use syntax::ast::{Item, ItemConst, ItemEnum, ItemExternCrate, ItemFn};
use syntax::ast::{ItemForeignMod, ItemImpl, ItemMac, ItemMod, ItemStatic, ItemDefaultImpl};
use syntax::ast::{ItemStruct, ItemTrait, ItemTy, ItemUse};
use syntax::ast::{Name, NamedField, NodeId};
use syntax::ast::{PathListIdent, PathListMod, Public};
use syntax::ast::StmtDecl;
use syntax::ast::StructVariantKind;
use syntax::ast::TupleVariantKind;
use syntax::ast::UnnamedField;
use syntax::ast::{Variant, ViewPathGlob, ViewPathList, ViewPathSimple};
use syntax::ast::Visibility;
use syntax::ast;
use syntax::ast_util::local_def;
use syntax::attr::AttrMetaMethods;
use syntax::parse::token::{self, special_idents};
use syntax::codemap::{Span, DUMMY_SP};
use syntax::visit::{self, Visitor};
use std::mem::replace;
use std::ops::{Deref, DerefMut};
use std::rc::Rc;
// Specifies how duplicates should be handled when adding a child item if
// another item exists with the same name in some namespace.
#[derive(Copy, Clone, PartialEq)]
enum DuplicateCheckingMode {
ForbidDuplicateModules,
ForbidDuplicateTypesAndModules,
ForbidDuplicateValues,
ForbidDuplicateTypesAndValues,
OverwriteDuplicates
}
#[derive(Copy, Clone, PartialEq)]
enum NamespaceError {
NoError,
ModuleError,
TypeError,
ValueError
}
fn namespace_error_to_string(ns: NamespaceError) -> &'static str {
match ns {
NoError => "",
ModuleError | TypeError => "type or module",
ValueError => "value",
}
}
struct GraphBuilder<'a, 'b:'a, 'tcx:'b> {
resolver: &'a mut Resolver<'b, 'tcx>
}
impl<'a, 'b:'a, 'tcx:'b> Deref for GraphBuilder<'a, 'b, 'tcx> {
type Target = Resolver<'b, 'tcx>;
fn deref(&self) -> &Resolver<'b, 'tcx> {
&*self.resolver
}
}
impl<'a, 'b:'a, 'tcx:'b> DerefMut for GraphBuilder<'a, 'b, 'tcx> {
fn deref_mut(&mut self) -> &mut Resolver<'b, 'tcx> {
&mut *self.resolver
}
}
impl<'a, 'b:'a, 'tcx:'b> GraphBuilder<'a, 'b, 'tcx> {
/// Constructs the reduced graph for the entire crate.
fn build_reduced_graph(self, krate: &ast::Crate) {
let parent = self.graph_root.get_module();
let mut visitor = BuildReducedGraphVisitor {
builder: self,
parent: parent
};
visit::walk_crate(&mut visitor, krate);
}
/// Adds a new child item to the module definition of the parent node and
/// returns its corresponding name bindings as well as the current parent.
/// Or, if we're inside a block, creates (or reuses) an anonymous module
/// corresponding to the innermost block ID and returns the name bindings
/// as well as the newly-created parent.
///
/// # Panics
///
/// Panics if this node does not have a module definition and we are not inside
/// a block.
fn add_child(&self,
name: Name,
parent: &Rc<Module>,
duplicate_checking_mode: DuplicateCheckingMode,
// For printing errors
sp: Span)
-> Rc<NameBindings> {
// If this is the immediate descendant of a module, then we add the
// child name directly. Otherwise, we create or reuse an anonymous
// module and add the child to that.
self.check_for_conflicts_between_external_crates_and_items(&**parent,
name,
sp);
// Add or reuse the child.
let child = parent.children.borrow().get(&name).cloned();
match child {
None => {
let child = Rc::new(NameBindings::new());
parent.children.borrow_mut().insert(name, child.clone());
child
}
Some(child) => {
// Enforce the duplicate checking mode:
//
// * If we're requesting duplicate module checking, check that
// there isn't a module in the module with the same name.
//
// * If we're requesting duplicate type checking, check that
// there isn't a type in the module with the same name.
//
// * If we're requesting duplicate value checking, check that
// there isn't a value in the module with the same name.
//
// * If we're requesting duplicate type checking and duplicate
// value checking, check that there isn't a duplicate type
// and a duplicate value with the same name.
//
// * If no duplicate checking was requested at all, do
// nothing.
let mut duplicate_type = NoError;
let ns = match duplicate_checking_mode {
ForbidDuplicateModules => {
if child.get_module_if_available().is_some() {
duplicate_type = ModuleError;
}
Some(TypeNS)
}
ForbidDuplicateTypesAndModules => {
if child.defined_in_namespace(TypeNS) {
duplicate_type = TypeError;
}
Some(TypeNS)
}
ForbidDuplicateValues => {
if child.defined_in_namespace(ValueNS) {
duplicate_type = ValueError;
}
Some(ValueNS)
}
ForbidDuplicateTypesAndValues => {
let mut n = None;
match child.def_for_namespace(TypeNS) {
Some(DefMod(_)) | None => {}
Some(_) => {
n = Some(TypeNS);
duplicate_type = TypeError;
}
};
if child.defined_in_namespace(ValueNS) {
duplicate_type = ValueError;
n = Some(ValueNS);
}
n
}
OverwriteDuplicates => None
};
if duplicate_type != NoError {
// Return an error here by looking up the namespace that
// had the duplicate.
let ns = ns.unwrap();
resolve_err!(self, sp, E0428,
"duplicate definition of {} `{}`",
namespace_error_to_string(duplicate_type),
token::get_name(name));
{
let r = child.span_for_namespace(ns);
if let Some(sp) = r {
self.session.span_note(sp,
&format!("first definition of {} `{}` here",
namespace_error_to_string(duplicate_type),
token::get_name(name)));
}
}
}
child
}
}
}
fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
// Check each statement.
for statement in &block.stmts {
match statement.node {
StmtDecl(ref declaration, _) => {
match declaration.node {
DeclItem(_) => {
return true;
}
_ => {
// Keep searching.
}
}
}
_ => {
// Keep searching.
}
}
}
// If we found no items, we don't need to create
// an anonymous module.
return false;
}
fn get_parent_link(&mut self, parent: &Rc<Module>, name: Name) -> ParentLink {
ModuleParentLink(parent.downgrade(), name)
}
/// Constructs the reduced graph for one item.
fn build_reduced_graph_for_item(&mut self, item: &Item, parent: &Rc<Module>) -> Rc<Module> {
let name = item.ident.name;
let sp = item.span;
let is_public = item.vis == ast::Public;
let modifiers = if is_public {
DefModifiers::PUBLIC
} else {
DefModifiers::empty()
} | DefModifiers::IMPORTABLE;
match item.node {
ItemUse(ref view_path) => {
// Extract and intern the module part of the path. For
// globs and lists, the path is found directly in the AST;
// for simple paths we have to munge the path a little.
let module_path = match view_path.node {
ViewPathSimple(_, ref full_path) => {
full_path.segments
.init()
.iter().map(|ident| ident.identifier.name)
.collect()
}
ViewPathGlob(ref module_ident_path) |
ViewPathList(ref module_ident_path, _) => {
module_ident_path.segments
.iter().map(|ident| ident.identifier.name).collect()
}
};
// Build up the import directives.
let shadowable = item.attrs.iter().any(|attr| {
attr.name() == token::get_name(special_idents::prelude_import.name)
});
let shadowable = if shadowable {
Shadowable::Always
} else {
Shadowable::Never
};
match view_path.node {
ViewPathSimple(binding, ref full_path) => {
let source_name =
full_path.segments.last().unwrap().identifier.name;
if &token::get_name(source_name)[..] == "mod" ||
&token::get_name(source_name)[..] == "self" {
resolve_err!(self, view_path.span, E0429,
"{}",
"`self` imports are only allowed within a { } list");
}
let subclass = SingleImport(binding.name,
source_name);
self.build_import_directive(&**parent,
module_path,
subclass,
view_path.span,
item.id,
is_public,
shadowable);
}
ViewPathList(_, ref source_items) => {
// Make sure there's at most one `mod` import in the list.
let mod_spans = source_items.iter().filter_map(|item| match item.node {
PathListMod { .. } => Some(item.span),
_ => None
}).collect::<Vec<Span>>();
if mod_spans.len() > 1 {
resolve_err!(self, mod_spans[0], E0430,
"{}",
"`self` import can only appear once in the list");
for other_span in mod_spans.iter().skip(1) {
self.session.span_note(*other_span,
"another `self` import appears here");
}
}
for source_item in source_items {
let (module_path, name) = match source_item.node {
PathListIdent { name, .. } =>
(module_path.clone(), name.name),
PathListMod { .. } => {
let name = match module_path.last() {
Some(name) => *name,
None => {
resolve_err!(self, source_item.span, E0431,
"{}",
"`self` import can only appear in an import list \
with a non-empty prefix");
continue;
}
};
let module_path = module_path.init();
(module_path.to_vec(), name)
}
};
self.build_import_directive(
&**parent,
module_path,
SingleImport(name, name),
source_item.span,
source_item.node.id(),
is_public,
shadowable);
}
}
ViewPathGlob(_) => {
self.build_import_directive(&**parent,
module_path,
GlobImport,
view_path.span,
item.id,
is_public,
shadowable);
}
}
parent.clone()
}
ItemExternCrate(_) => {
// n.b. we don't need to look at the path option here, because cstore already did
if let Some(crate_id) = self.session.cstore.find_extern_mod_stmt_cnum(item.id) {
let def_id = DefId { krate: crate_id, node: 0 };
self.external_exports.insert(def_id);
let parent_link = ModuleParentLink(parent.downgrade(), name);
let external_module = Rc::new(Module::new(parent_link,
Some(def_id),
NormalModuleKind,
false,
true));
debug!("(build reduced graph for item) found extern `{}`",
module_to_string(&*external_module));
self.check_for_conflicts_between_external_crates(&**parent, name, sp);
parent.external_module_children.borrow_mut()
.insert(name, external_module.clone());
self.build_reduced_graph_for_external_crate(&external_module);
}
parent.clone()
}
ItemMod(..) => {
let name_bindings = self.add_child(name, parent, ForbidDuplicateModules, sp);
let parent_link = self.get_parent_link(parent, name);
let def_id = DefId { krate: 0, node: item.id };
name_bindings.define_module(parent_link,
Some(def_id),
NormalModuleKind,
false,
is_public,
sp);
name_bindings.get_module()
}
ItemForeignMod(..) => parent.clone(),
// These items live in the value namespace.
ItemStatic(_, m, _) => {
let name_bindings = self.add_child(name, parent, ForbidDuplicateValues, sp);
let mutbl = m == ast::MutMutable;
name_bindings.define_value(DefStatic(local_def(item.id), mutbl), sp, modifiers);
parent.clone()
}
ItemConst(_, _) => {
self.add_child(name, parent, ForbidDuplicateValues, sp)
.define_value(DefConst(local_def(item.id)), sp, modifiers);
parent.clone()
}
ItemFn(_, _, _, _, _, _) => {
let name_bindings = self.add_child(name, parent, ForbidDuplicateValues, sp);
let def = DefFn(local_def(item.id), false);
name_bindings.define_value(def, sp, modifiers);
parent.clone()
}
// These items live in the type namespace.
ItemTy(..) => {
let name_bindings =
self.add_child(name, parent, ForbidDuplicateTypesAndModules, sp);
name_bindings.define_type(DefTy(local_def(item.id), false), sp,
modifiers);
let parent_link = self.get_parent_link(parent, name);
name_bindings.set_module_kind(parent_link,
Some(local_def(item.id)),
TypeModuleKind,
false,
is_public,
sp);
parent.clone()
}
ItemEnum(ref enum_definition, _) => {
let name_bindings =
self.add_child(name, parent, ForbidDuplicateTypesAndModules, sp);
name_bindings.define_type(DefTy(local_def(item.id), true), sp, modifiers);
let parent_link = self.get_parent_link(parent, name);
name_bindings.set_module_kind(parent_link,
Some(local_def(item.id)),
EnumModuleKind,
false,
is_public,
sp);
let module = name_bindings.get_module();
for variant in &(*enum_definition).variants {
self.build_reduced_graph_for_variant(
&**variant,
local_def(item.id),
&module);
}
parent.clone()
}
// These items live in both the type and value namespaces.
ItemStruct(ref struct_def, _) => {
// Adding to both Type and Value namespaces or just Type?
let (forbid, ctor_id) = match struct_def.ctor_id {
Some(ctor_id) => (ForbidDuplicateTypesAndValues, Some(ctor_id)),
None => (ForbidDuplicateTypesAndModules, None)
};
let name_bindings = self.add_child(name, parent, forbid, sp);
// Define a name in the type namespace.
name_bindings.define_type(DefTy(local_def(item.id), false), sp, modifiers);
// If this is a newtype or unit-like struct, define a name
// in the value namespace as well
if let Some(cid) = ctor_id {
name_bindings.define_value(DefStruct(local_def(cid)), sp, modifiers);
}
// Record the def ID and fields of this struct.
let named_fields = struct_def.fields.iter().filter_map(|f| {
match f.node.kind {
NamedField(ident, _) => Some(ident.name),
UnnamedField(_) => None
}
}).collect();
self.structs.insert(local_def(item.id), named_fields);
parent.clone()
}
ItemDefaultImpl(_, _) |
ItemImpl(..) => parent.clone(),
ItemTrait(_, _, _, ref items) => {
let name_bindings =
self.add_child(name, parent, ForbidDuplicateTypesAndModules, sp);
// Add all the items within to a new module.
let parent_link = self.get_parent_link(parent, name);
name_bindings.define_module(parent_link,
Some(local_def(item.id)),
TraitModuleKind,
false,
is_public,
sp);
let module_parent = name_bindings.get_module();
let def_id = local_def(item.id);
// Add the names of all the items to the trait info.
for trait_item in items {
let name_bindings = self.add_child(trait_item.ident.name,
&module_parent,
ForbidDuplicateTypesAndValues,
trait_item.span);
match trait_item.node {
ast::ConstTraitItem(..) => {
let def = DefAssociatedConst(local_def(trait_item.id),
FromTrait(local_def(item.id)));
// NB: not DefModifiers::IMPORTABLE
name_bindings.define_value(def, trait_item.span, DefModifiers::PUBLIC);
}
ast::MethodTraitItem(..) => {
let def = DefMethod(local_def(trait_item.id),
FromTrait(local_def(item.id)));
// NB: not DefModifiers::IMPORTABLE
name_bindings.define_value(def, trait_item.span, DefModifiers::PUBLIC);
}
ast::TypeTraitItem(..) => {
let def = DefAssociatedTy(local_def(item.id),
local_def(trait_item.id));
// NB: not DefModifiers::IMPORTABLE
name_bindings.define_type(def, trait_item.span, DefModifiers::PUBLIC);
}
}
self.trait_item_map.insert((trait_item.ident.name, def_id),
local_def(trait_item.id));
}
name_bindings.define_type(DefTrait(def_id), sp, modifiers);
parent.clone()
}
ItemMac(..) => parent.clone()
}
}
// Constructs the reduced graph for one variant. Variants exist in the
// type and value namespaces.
fn build_reduced_graph_for_variant(&mut self,
variant: &Variant,
item_id: DefId,
parent: &Rc<Module>) {
let name = variant.node.name.name;
let is_exported = match variant.node.kind {
TupleVariantKind(_) => false,
StructVariantKind(_) => {
// Not adding fields for variants as they are not accessed with a self receiver
self.structs.insert(local_def(variant.node.id), Vec::new());
true
}
};
let child = self.add_child(name, parent,
ForbidDuplicateTypesAndValues,
variant.span);
// variants are always treated as importable to allow them to be glob
// used
child.define_value(DefVariant(item_id,
local_def(variant.node.id), is_exported),
variant.span, DefModifiers::PUBLIC | DefModifiers::IMPORTABLE);
child.define_type(DefVariant(item_id,
local_def(variant.node.id), is_exported),
variant.span, DefModifiers::PUBLIC | DefModifiers::IMPORTABLE);
}
/// Constructs the reduced graph for one foreign item.
fn build_reduced_graph_for_foreign_item(&mut self,
foreign_item: &ForeignItem,
parent: &Rc<Module>) {
let name = foreign_item.ident.name;
let is_public = foreign_item.vis == ast::Public;
let modifiers = if is_public {
DefModifiers::PUBLIC
} else {
DefModifiers::empty()
} | DefModifiers::IMPORTABLE;
let name_bindings =
self.add_child(name, parent, ForbidDuplicateValues,
foreign_item.span);
let def = match foreign_item.node {
ForeignItemFn(..) => {
DefFn(local_def(foreign_item.id), false)
}
ForeignItemStatic(_, m) => {
DefStatic(local_def(foreign_item.id), m)
}
};
name_bindings.define_value(def, foreign_item.span, modifiers);
}
fn build_reduced_graph_for_block(&mut self, block: &Block, parent: &Rc<Module>) -> Rc<Module> {
if self.block_needs_anonymous_module(block) {
let block_id = block.id;
debug!("(building reduced graph for block) creating a new \
anonymous module for block {}",
block_id);
let new_module = Rc::new(Module::new(
BlockParentLink(parent.downgrade(), block_id),
None,
AnonymousModuleKind,
false,
false));
parent.anonymous_children.borrow_mut().insert(block_id, new_module.clone());
new_module
} else {
parent.clone()
}
}
fn handle_external_def(&mut self,
def: Def,
vis: Visibility,
child_name_bindings: &NameBindings,
final_ident: &str,
name: Name,
new_parent: &Rc<Module>) {
debug!("(building reduced graph for \
external crate) building external def {}, priv {:?}",
final_ident, vis);
let is_public = vis == ast::Public;
let modifiers = if is_public {
DefModifiers::PUBLIC
} else {
DefModifiers::empty()
} | DefModifiers::IMPORTABLE;
let is_exported = is_public && match new_parent.def_id.get() {
None => true,
Some(did) => self.external_exports.contains(&did)
};
if is_exported {
self.external_exports.insert(def.def_id());
}
let kind = match def {
DefTy(_, true) => EnumModuleKind,
DefTy(_, false) | DefStruct(..) => TypeModuleKind,
_ => NormalModuleKind
};
match def {
DefMod(def_id) | DefForeignMod(def_id) | DefStruct(def_id) |
DefTy(def_id, _) => {
let type_def = child_name_bindings.type_def.borrow().clone();
match type_def {
Some(TypeNsDef { module_def: Some(module_def), .. }) => {
debug!("(building reduced graph for external crate) \
already created module");
module_def.def_id.set(Some(def_id));
}
Some(_) | None => {
debug!("(building reduced graph for \
external crate) building module \
{} {}", final_ident, is_public);
let parent_link = self.get_parent_link(new_parent, name);
child_name_bindings.define_module(parent_link,
Some(def_id),
kind,
true,
is_public,
DUMMY_SP);
}
}
}
_ => {}
}
match def {
DefMod(_) | DefForeignMod(_) => {}
DefVariant(_, variant_id, is_struct) => {
debug!("(building reduced graph for external crate) building \
variant {}",
final_ident);
// variants are always treated as importable to allow them to be
// glob used
let modifiers = DefModifiers::PUBLIC | DefModifiers::IMPORTABLE;
if is_struct {
child_name_bindings.define_type(def, DUMMY_SP, modifiers);
// Not adding fields for variants as they are not accessed with a self receiver
self.structs.insert(variant_id, Vec::new());
} else {
child_name_bindings.define_value(def, DUMMY_SP, modifiers);
}
}
DefFn(ctor_id, true) => {
child_name_bindings.define_value(
csearch::get_tuple_struct_definition_if_ctor(&self.session.cstore, ctor_id)
.map_or(def, |_| DefStruct(ctor_id)), DUMMY_SP, modifiers);
}
DefFn(..) | DefStatic(..) | DefConst(..) | DefAssociatedConst(..) |
DefMethod(..) => {
debug!("(building reduced graph for external \
crate) building value (fn/static) {}", final_ident);
// impl methods have already been defined with the correct importability modifier
let mut modifiers = match *child_name_bindings.value_def.borrow() {
Some(ref def) => (modifiers & !DefModifiers::IMPORTABLE) |
(def.modifiers & DefModifiers::IMPORTABLE),
None => modifiers
};
if new_parent.kind.get() != NormalModuleKind {
modifiers = modifiers & !DefModifiers::IMPORTABLE;
}
child_name_bindings.define_value(def, DUMMY_SP, modifiers);
}
DefTrait(def_id) => {
debug!("(building reduced graph for external \
crate) building type {}", final_ident);
// If this is a trait, add all the trait item names to the trait
// info.
let trait_item_def_ids =
csearch::get_trait_item_def_ids(&self.session.cstore, def_id);
for trait_item_def in &trait_item_def_ids {
let trait_item_name = csearch::get_trait_name(&self.session.cstore,
trait_item_def.def_id());
debug!("(building reduced graph for external crate) ... \
adding trait item '{}'",
token::get_name(trait_item_name));
self.trait_item_map.insert((trait_item_name, def_id),
trait_item_def.def_id());
if is_exported {
self.external_exports.insert(trait_item_def.def_id());
}
}
child_name_bindings.define_type(def, DUMMY_SP, modifiers);
// Define a module if necessary.
let parent_link = self.get_parent_link(new_parent, name);
child_name_bindings.set_module_kind(parent_link,
Some(def_id),
TraitModuleKind,
true,
is_public,
DUMMY_SP)
}
DefTy(..) | DefAssociatedTy(..) => {
debug!("(building reduced graph for external \
crate) building type {}", final_ident);
child_name_bindings.define_type(def, DUMMY_SP, modifiers);
}
DefStruct(def_id) => {
debug!("(building reduced graph for external \
crate) building type and value for {}",
final_ident);
child_name_bindings.define_type(def, DUMMY_SP, modifiers);
let fields = csearch::get_struct_fields(&self.session.cstore, def_id).iter().map(|f| {
f.name
}).collect::<Vec<_>>();
if fields.is_empty() {
child_name_bindings.define_value(def, DUMMY_SP, modifiers);
}
// Record the def ID and fields of this struct.
self.structs.insert(def_id, fields);
}
DefLocal(..) | DefPrimTy(..) | DefTyParam(..) |
DefUse(..) | DefUpvar(..) | DefRegion(..) |
DefLabel(..) | DefSelfTy(..) => {
panic!("didn't expect `{:?}`", def);
}
}
}
/// Builds the reduced graph for a single item in an external crate.
fn build_reduced_graph_for_external_crate_def(&mut self,
root: &Rc<Module>,
def_like: DefLike,
name: Name,
def_visibility: Visibility) {
match def_like {
DlDef(def) => {
// Add the new child item, if necessary.
match def {
DefForeignMod(def_id) => {
// Foreign modules have no names. Recur and populate
// eagerly.
csearch::each_child_of_item(&self.session.cstore,
def_id,
|def_like,
child_name,
vis| {
self.build_reduced_graph_for_external_crate_def(
root,
def_like,
child_name,
vis)
});
}
_ => {
let child_name_bindings =
self.add_child(name,
root,
OverwriteDuplicates,
DUMMY_SP);
self.handle_external_def(def,
def_visibility,
&*child_name_bindings,
&token::get_name(name),
name,
root);
}
}
}
DlImpl(_) => {
debug!("(building reduced graph for external crate) \
ignoring impl");
}
DlField => {
debug!("(building reduced graph for external crate) \
ignoring field");
}
}
}
/// Builds the reduced graph rooted at the given external module.
fn populate_external_module(&mut self, module: &Rc<Module>) {
debug!("(populating external module) attempting to populate {}",
module_to_string(&**module));
let def_id = match module.def_id.get() {
None => {
debug!("(populating external module) ... no def ID!");
return
}
Some(def_id) => def_id,
};
csearch::each_child_of_item(&self.session.cstore,
def_id,
|def_like, child_name, visibility| {
debug!("(populating external module) ... found ident: {}",
token::get_name(child_name));
self.build_reduced_graph_for_external_crate_def(module,
def_like,
child_name,
visibility)
});
module.populated.set(true)
}
/// Ensures that the reduced graph rooted at the given external module
/// is built, building it if it is not.
fn populate_module_if_necessary(&mut self, module: &Rc<Module>) {
if !module.populated.get() {
self.populate_external_module(module)
}
assert!(module.populated.get())
}
/// Builds the reduced graph rooted at the 'use' directive for an external
/// crate.
fn build_reduced_graph_for_external_crate(&mut self, root: &Rc<Module>) {
csearch::each_top_level_item_of_crate(&self.session.cstore,
root.def_id
.get()
.unwrap()
.krate,
|def_like, name, visibility| {
self.build_reduced_graph_for_external_crate_def(root, def_like, name, visibility)
});
}
/// Creates and adds an import directive to the given module.
fn build_import_directive(&mut self,
module_: &Module,
module_path: Vec<Name>,
subclass: ImportDirectiveSubclass,
span: Span,
id: NodeId,
is_public: bool,
shadowable: Shadowable) {
module_.imports.borrow_mut().push(ImportDirective::new(module_path,
subclass,
span,
id,
is_public,
shadowable));
self.unresolved_imports += 1;
// Bump the reference count on the name. Or, if this is a glob, set
// the appropriate flag.
match subclass {
SingleImport(target, _) => {
debug!("(building import directive) building import directive: {}::{}",
names_to_string(&module_.imports.borrow().last().unwrap().module_path),
token::get_name(target));
let mut import_resolutions = module_.import_resolutions.borrow_mut();
match import_resolutions.get_mut(&target) {
Some(resolution) => {
debug!("(building import directive) bumping reference");
resolution.outstanding_references += 1;
// the source of this name is different now
resolution.type_id = id;
resolution.value_id = id;
resolution.is_public = is_public;
return;
}
None => {}
}
debug!("(building import directive) creating new");
let mut resolution = ImportResolution::new(id, is_public);
resolution.outstanding_references = 1;
import_resolutions.insert(target, resolution);
}
GlobImport => {
// Set the glob flag. This tells us that we don't know the
// module's exports ahead of time.
module_.glob_count.set(module_.glob_count.get() + 1);
}
}
}
}
struct BuildReducedGraphVisitor<'a, 'b:'a, 'tcx:'b> {
builder: GraphBuilder<'a, 'b, 'tcx>,
parent: Rc<Module>
}
impl<'a, 'b, 'v, 'tcx> Visitor<'v> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
fn visit_item(&mut self, item: &Item) {
let p = self.builder.build_reduced_graph_for_item(item, &self.parent);
let old_parent = replace(&mut self.parent, p);
visit::walk_item(self, item);
self.parent = old_parent;
}
fn visit_foreign_item(&mut self, foreign_item: &ForeignItem) {
self.builder.build_reduced_graph_for_foreign_item(foreign_item, &self.parent);
}
fn visit_block(&mut self, block: &Block) {
let np = self.builder.build_reduced_graph_for_block(block, &self.parent);
let old_parent = replace(&mut self.parent, np);
visit::walk_block(self, block);
self.parent = old_parent;
}
}
pub fn build_reduced_graph(resolver: &mut Resolver, krate: &ast::Crate) {
GraphBuilder {
resolver: resolver
}.build_reduced_graph(krate);
}
pub fn populate_module_if_necessary(resolver: &mut Resolver, module: &Rc<Module>) {
GraphBuilder {
resolver: resolver
}.populate_module_if_necessary(module);
}