rust/src/librustc/middle/privacy.rs
Edward Wang 899f222386 Calibrate span for method call error messages
Specifically, the method parameter cardinality mismatch or missing
method error message span now gets method itself exactly. It was the
whole expression.

Closes #9390
Closes #13684
Closes #13709
2014-04-24 06:16:46 +08:00

1469 lines
60 KiB
Rust

// Copyright 2012-2013 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.
//! A pass that checks to make sure private fields and methods aren't used
//! outside their scopes. This pass will also generate a set of exported items
//! which are available for use externally when compiled as a library.
use std::mem::replace;
use metadata::csearch;
use middle::lint;
use middle::resolve;
use middle::ty;
use middle::typeck::{MethodCall, MethodMap, MethodOrigin, MethodParam};
use middle::typeck::{MethodStatic, MethodObject};
use util::nodemap::{NodeMap, NodeSet};
use syntax::ast;
use syntax::ast_map;
use syntax::ast_util::{is_local, def_id_of_def, local_def};
use syntax::attr;
use syntax::codemap::Span;
use syntax::parse::token;
use syntax::owned_slice::OwnedSlice;
use syntax::visit;
use syntax::visit::Visitor;
type Context<'a> = (&'a MethodMap, &'a resolve::ExportMap2);
/// A set of AST nodes exported by the crate.
pub type ExportedItems = NodeSet;
/// A set of AST nodes that are fully public in the crate. This map is used for
/// documentation purposes (reexporting a private struct inlines the doc,
/// reexporting a public struct doesn't inline the doc).
pub type PublicItems = NodeSet;
/// Result of a checking operation - None => no errors were found. Some => an
/// error and contains the span and message for reporting that error and
/// optionally the same for a note about the error.
type CheckResult = Option<(Span, ~str, Option<(Span, ~str)>)>;
////////////////////////////////////////////////////////////////////////////////
/// The parent visitor, used to determine what's the parent of what (node-wise)
////////////////////////////////////////////////////////////////////////////////
struct ParentVisitor {
parents: NodeMap<ast::NodeId>,
curparent: ast::NodeId,
}
impl Visitor<()> for ParentVisitor {
fn visit_item(&mut self, item: &ast::Item, _: ()) {
self.parents.insert(item.id, self.curparent);
let prev = self.curparent;
match item.node {
ast::ItemMod(..) => { self.curparent = item.id; }
// Enum variants are parented to the enum definition itself because
// they inherit privacy
ast::ItemEnum(ref def, _) => {
for variant in def.variants.iter() {
// The parent is considered the enclosing enum because the
// enum will dictate the privacy visibility of this variant
// instead.
self.parents.insert(variant.node.id, item.id);
}
}
// Trait methods are always considered "public", but if the trait is
// private then we need some private item in the chain from the
// method to the root. In this case, if the trait is private, then
// parent all the methods to the trait to indicate that they're
// private.
ast::ItemTrait(_, _, _, ref methods) if item.vis != ast::Public => {
for m in methods.iter() {
match *m {
ast::Provided(ref m) => self.parents.insert(m.id, item.id),
ast::Required(ref m) => self.parents.insert(m.id, item.id),
};
}
}
_ => {}
}
visit::walk_item(self, item, ());
self.curparent = prev;
}
fn visit_foreign_item(&mut self, a: &ast::ForeignItem, _: ()) {
self.parents.insert(a.id, self.curparent);
visit::walk_foreign_item(self, a, ());
}
fn visit_fn(&mut self, a: &visit::FnKind, b: &ast::FnDecl,
c: &ast::Block, d: Span, id: ast::NodeId, _: ()) {
// We already took care of some trait methods above, otherwise things
// like impl methods and pub trait methods are parented to the
// containing module, not the containing trait.
if !self.parents.contains_key(&id) {
self.parents.insert(id, self.curparent);
}
visit::walk_fn(self, a, b, c, d, id, ());
}
fn visit_struct_def(&mut self, s: &ast::StructDef, i: ast::Ident,
g: &ast::Generics, n: ast::NodeId, _: ()) {
// Struct constructors are parented to their struct definitions because
// they essentially are the struct definitions.
match s.ctor_id {
Some(id) => { self.parents.insert(id, n); }
None => {}
}
// While we have the id of the struct definition, go ahead and parent
// all the fields.
for field in s.fields.iter() {
self.parents.insert(field.node.id, self.curparent);
}
visit::walk_struct_def(self, s, i, g, n, ())
}
}
////////////////////////////////////////////////////////////////////////////////
/// The embargo visitor, used to determine the exports of the ast
////////////////////////////////////////////////////////////////////////////////
struct EmbargoVisitor<'a> {
tcx: &'a ty::ctxt,
exp_map2: &'a resolve::ExportMap2,
// This flag is an indicator of whether the previous item in the
// hierarchical chain was exported or not. This is the indicator of whether
// children should be exported as well. Note that this can flip from false
// to true if a reexported module is entered (or an action similar).
prev_exported: bool,
// This is a list of all exported items in the AST. An exported item is any
// function/method/item which is usable by external crates. This essentially
// means that the result is "public all the way down", but the "path down"
// may jump across private boundaries through reexport statements.
exported_items: ExportedItems,
// This sets contains all the destination nodes which are publicly
// re-exported. This is *not* a set of all reexported nodes, only a set of
// all nodes which are reexported *and* reachable from external crates. This
// means that the destination of the reexport is exported, and hence the
// destination must also be exported.
reexports: NodeSet,
// These two fields are closely related to one another in that they are only
// used for generation of the 'PublicItems' set, not for privacy checking at
// all
public_items: PublicItems,
prev_public: bool,
}
impl<'a> EmbargoVisitor<'a> {
// There are checks inside of privacy which depend on knowing whether a
// trait should be exported or not. The two current consumers of this are:
//
// 1. Should default methods of a trait be exported?
// 2. Should the methods of an implementation of a trait be exported?
//
// The answer to both of these questions partly rely on whether the trait
// itself is exported or not. If the trait is somehow exported, then the
// answers to both questions must be yes. Right now this question involves
// more analysis than is currently done in rustc, so we conservatively
// answer "yes" so that all traits need to be exported.
fn exported_trait(&self, _id: ast::NodeId) -> bool {
true
}
}
impl<'a> Visitor<()> for EmbargoVisitor<'a> {
fn visit_item(&mut self, item: &ast::Item, _: ()) {
let orig_all_pub = self.prev_public;
self.prev_public = orig_all_pub && item.vis == ast::Public;
if self.prev_public {
self.public_items.insert(item.id);
}
let orig_all_exported = self.prev_exported;
match item.node {
// impls/extern blocks do not break the "public chain" because they
// cannot have visibility qualifiers on them anyway
ast::ItemImpl(..) | ast::ItemForeignMod(..) => {}
// Traits are a little special in that even if they themselves are
// not public they may still be exported.
ast::ItemTrait(..) => {
self.prev_exported = self.exported_trait(item.id);
}
// Private by default, hence we only retain the "public chain" if
// `pub` is explicitly listed.
_ => {
self.prev_exported =
(orig_all_exported && item.vis == ast::Public) ||
self.reexports.contains(&item.id);
}
}
let public_first = self.prev_exported &&
self.exported_items.insert(item.id);
match item.node {
// Enum variants inherit from their parent, so if the enum is
// public all variants are public unless they're explicitly priv
ast::ItemEnum(ref def, _) if public_first => {
for variant in def.variants.iter() {
self.exported_items.insert(variant.node.id);
}
}
// Implementations are a little tricky to determine what's exported
// out of them. Here's a few cases which are currently defined:
//
// * Impls for private types do not need to export their methods
// (either public or private methods)
//
// * Impls for public types only have public methods exported
//
// * Public trait impls for public types must have all methods
// exported.
//
// * Private trait impls for public types can be ignored
//
// * Public trait impls for private types have their methods
// exported. I'm not entirely certain that this is the correct
// thing to do, but I have seen use cases of where this will cause
// undefined symbols at linkage time if this case is not handled.
//
// * Private trait impls for private types can be completely ignored
ast::ItemImpl(_, _, ref ty, ref methods) => {
let public_ty = match ty.node {
ast::TyPath(_, _, id) => {
match self.tcx.def_map.borrow().get_copy(&id) {
ast::DefPrimTy(..) => true,
def => {
let did = def_id_of_def(def);
!is_local(did) ||
self.exported_items.contains(&did.node)
}
}
}
_ => true,
};
let tr = ty::impl_trait_ref(self.tcx, local_def(item.id));
let public_trait = tr.clone().map_or(false, |tr| {
!is_local(tr.def_id) ||
self.exported_items.contains(&tr.def_id.node)
});
if public_ty || public_trait {
for method in methods.iter() {
let meth_public = match method.explicit_self.node {
ast::SelfStatic => public_ty,
_ => true,
} && method.vis == ast::Public;
if meth_public || tr.is_some() {
self.exported_items.insert(method.id);
}
}
}
}
// Default methods on traits are all public so long as the trait
// is public
ast::ItemTrait(_, _, _, ref methods) if public_first => {
for method in methods.iter() {
match *method {
ast::Provided(ref m) => {
debug!("provided {}", m.id);
self.exported_items.insert(m.id);
}
ast::Required(ref m) => {
debug!("required {}", m.id);
self.exported_items.insert(m.id);
}
}
}
}
// Struct constructors are public if the struct is all public.
ast::ItemStruct(ref def, _) if public_first => {
match def.ctor_id {
Some(id) => { self.exported_items.insert(id); }
None => {}
}
}
_ => {}
}
visit::walk_item(self, item, ());
self.prev_exported = orig_all_exported;
self.prev_public = orig_all_pub;
}
fn visit_foreign_item(&mut self, a: &ast::ForeignItem, _: ()) {
if self.prev_exported && a.vis == ast::Public {
self.exported_items.insert(a.id);
}
}
fn visit_mod(&mut self, m: &ast::Mod, _sp: Span, id: ast::NodeId, _: ()) {
// This code is here instead of in visit_item so that the
// crate module gets processed as well.
if self.prev_exported {
let exp_map2 = self.exp_map2.borrow();
assert!(exp_map2.contains_key(&id), "wut {:?}", id);
for export in exp_map2.get(&id).iter() {
if is_local(export.def_id) {
self.reexports.insert(export.def_id.node);
}
}
}
visit::walk_mod(self, m, ())
}
}
////////////////////////////////////////////////////////////////////////////////
/// The privacy visitor, where privacy checks take place (violations reported)
////////////////////////////////////////////////////////////////////////////////
struct PrivacyVisitor<'a> {
tcx: &'a ty::ctxt,
curitem: ast::NodeId,
in_fn: bool,
in_foreign: bool,
parents: NodeMap<ast::NodeId>,
external_exports: resolve::ExternalExports,
last_private_map: resolve::LastPrivateMap,
}
enum PrivacyResult {
Allowable,
ExternallyDenied,
DisallowedBy(ast::NodeId),
}
enum FieldName {
UnnamedField(uint), // index
// FIXME #6993: change type (and name) from Ident to Name
NamedField(ast::Ident),
}
impl<'a> PrivacyVisitor<'a> {
// used when debugging
fn nodestr(&self, id: ast::NodeId) -> ~str {
self.tcx.map.node_to_str(id)
}
// Determines whether the given definition is public from the point of view
// of the current item.
fn def_privacy(&self, did: ast::DefId) -> PrivacyResult {
if !is_local(did) {
if self.external_exports.contains(&did) {
debug!("privacy - {:?} was externally exported", did);
return Allowable;
}
debug!("privacy - is {:?} a public method", did);
return match self.tcx.methods.borrow().find(&did) {
Some(meth) => {
debug!("privacy - well at least it's a method: {:?}", meth);
match meth.container {
ty::TraitContainer(id) => {
debug!("privacy - recursing on trait {:?}", id);
self.def_privacy(id)
}
ty::ImplContainer(id) => {
match ty::impl_trait_ref(self.tcx, id) {
Some(t) => {
debug!("privacy - impl of trait {:?}", id);
self.def_privacy(t.def_id)
}
None => {
debug!("privacy - found a method {:?}",
meth.vis);
if meth.vis == ast::Public {
Allowable
} else {
ExternallyDenied
}
}
}
}
}
}
None => {
debug!("privacy - nope, not even a method");
ExternallyDenied
}
};
}
debug!("privacy - local {} not public all the way down",
self.tcx.map.node_to_str(did.node));
// return quickly for things in the same module
if self.parents.find(&did.node) == self.parents.find(&self.curitem) {
debug!("privacy - same parent, we're done here");
return Allowable;
}
// We now know that there is at least one private member between the
// destination and the root.
let mut closest_private_id = did.node;
loop {
debug!("privacy - examining {}", self.nodestr(closest_private_id));
let vis = match self.tcx.map.find(closest_private_id) {
// If this item is a method, then we know for sure that it's an
// actual method and not a static method. The reason for this is
// that these cases are only hit in the ExprMethodCall
// expression, and ExprCall will have its path checked later
// (the path of the trait/impl) if it's a static method.
//
// With this information, then we can completely ignore all
// trait methods. The privacy violation would be if the trait
// couldn't get imported, not if the method couldn't be used
// (all trait methods are public).
//
// However, if this is an impl method, then we dictate this
// decision solely based on the privacy of the method
// invocation.
// FIXME(#10573) is this the right behavior? Why not consider
// where the method was defined?
Some(ast_map::NodeMethod(ref m)) => {
let imp = self.tcx.map.get_parent_did(closest_private_id);
match ty::impl_trait_ref(self.tcx, imp) {
Some(..) => return Allowable,
_ if m.vis == ast::Public => return Allowable,
_ => m.vis
}
}
Some(ast_map::NodeTraitMethod(_)) => {
return Allowable;
}
// This is not a method call, extract the visibility as one
// would normally look at it
Some(ast_map::NodeItem(it)) => it.vis,
Some(ast_map::NodeForeignItem(_)) => {
self.tcx.map.get_foreign_vis(closest_private_id)
}
Some(ast_map::NodeVariant(..)) => {
ast::Public // need to move up a level (to the enum)
}
_ => ast::Public,
};
if vis != ast::Public { break }
// if we've reached the root, then everything was allowable and this
// access is public.
if closest_private_id == ast::CRATE_NODE_ID { return Allowable }
closest_private_id = *self.parents.get(&closest_private_id);
// If we reached the top, then we were public all the way down and
// we can allow this access.
if closest_private_id == ast::DUMMY_NODE_ID { return Allowable }
}
debug!("privacy - closest priv {}", self.nodestr(closest_private_id));
if self.private_accessible(closest_private_id) {
Allowable
} else {
DisallowedBy(closest_private_id)
}
}
/// For a local private node in the AST, this function will determine
/// whether the node is accessible by the current module that iteration is
/// inside.
fn private_accessible(&self, id: ast::NodeId) -> bool {
let parent = *self.parents.get(&id);
debug!("privacy - accessible parent {}", self.nodestr(parent));
// After finding `did`'s closest private member, we roll ourselves back
// to see if this private member's parent is anywhere in our ancestry.
// By the privacy rules, we can access all of our ancestor's private
// members, so that's why we test the parent, and not the did itself.
let mut cur = self.curitem;
loop {
debug!("privacy - questioning {}, {:?}", self.nodestr(cur), cur);
match cur {
// If the relevant parent is in our history, then we're allowed
// to look inside any of our ancestor's immediate private items,
// so this access is valid.
x if x == parent => return true,
// If we've reached the root, then we couldn't access this item
// in the first place
ast::DUMMY_NODE_ID => return false,
// Keep going up
_ => {}
}
cur = *self.parents.get(&cur);
}
}
fn report_error(&self, result: CheckResult) -> bool {
match result {
None => true,
Some((span, msg, note)) => {
self.tcx.sess.span_err(span, msg);
match note {
Some((span, msg)) => self.tcx.sess.span_note(span, msg),
None => {},
}
false
},
}
}
/// Guarantee that a particular definition is public. Returns a CheckResult
/// which contains any errors found. These can be reported using `report_error`.
/// If the result is `None`, no errors were found.
fn ensure_public(&self, span: Span, to_check: ast::DefId,
source_did: Option<ast::DefId>, msg: &str) -> CheckResult {
let id = match self.def_privacy(to_check) {
ExternallyDenied => {
return Some((span, format!("{} is private", msg), None))
}
Allowable => return None,
DisallowedBy(id) => id,
};
// If we're disallowed by a particular id, then we attempt to give a
// nice error message to say why it was disallowed. It was either
// because the item itself is private or because its parent is private
// and its parent isn't in our ancestry.
let (err_span, err_msg) = if id == source_did.unwrap_or(to_check).node {
return Some((span, format!("{} is private", msg), None));
} else {
(span, format!("{} is inaccessible", msg))
};
let item = match self.tcx.map.find(id) {
Some(ast_map::NodeItem(item)) => {
match item.node {
// If an impl disallowed this item, then this is resolve's
// way of saying that a struct/enum's static method was
// invoked, and the struct/enum itself is private. Crawl
// back up the chains to find the relevant struct/enum that
// was private.
ast::ItemImpl(_, _, ref ty, _) => {
let id = match ty.node {
ast::TyPath(_, _, id) => id,
_ => return Some((err_span, err_msg, None)),
};
let def = self.tcx.def_map.borrow().get_copy(&id);
let did = def_id_of_def(def);
assert!(is_local(did));
match self.tcx.map.get(did.node) {
ast_map::NodeItem(item) => item,
_ => self.tcx.sess.span_bug(item.span,
"path is not an item")
}
}
_ => item
}
}
Some(..) | None => return Some((err_span, err_msg, None)),
};
let desc = match item.node {
ast::ItemMod(..) => "module",
ast::ItemTrait(..) => "trait",
ast::ItemStruct(..) => "struct",
ast::ItemEnum(..) => "enum",
_ => return Some((err_span, err_msg, None))
};
let msg = format!("{} `{}` is private", desc,
token::get_ident(item.ident));
Some((err_span, err_msg, Some((span, msg))))
}
// Checks that a field is in scope.
fn check_field(&mut self,
span: Span,
id: ast::DefId,
name: FieldName) {
let fields = ty::lookup_struct_fields(self.tcx, id);
let field = match name {
NamedField(ident) => {
debug!("privacy - check named field {} in struct {}", ident.name, id);
fields.iter().find(|f| f.name == ident.name).unwrap()
}
UnnamedField(idx) => fields.get(idx)
};
if field.vis == ast::Public ||
(is_local(field.id) && self.private_accessible(field.id.node)) {
return
}
let struct_type = ty::lookup_item_type(self.tcx, id).ty;
let struct_desc = match ty::get(struct_type).sty {
ty::ty_struct(_, _) => format!("struct `{}`", ty::item_path_str(self.tcx, id)),
ty::ty_bare_fn(ty::BareFnTy { sig: ty::FnSig { output, .. }, .. }) => {
// Struct `id` is really a struct variant of an enum,
// and we're really looking at the variant's constructor
// function. So get the return type for a detailed error
// message.
let enum_id = match ty::get(output).sty {
ty::ty_enum(id, _) => id,
_ => self.tcx.sess.span_bug(span, "enum variant doesn't \
belong to an enum")
};
format!("variant `{}` of enum `{}`",
ty::with_path(self.tcx, id, |mut p| p.last().unwrap()),
ty::item_path_str(self.tcx, enum_id))
}
_ => self.tcx.sess.span_bug(span, "can't find struct for field")
};
let msg = match name {
NamedField(name) => format!("field `{}` of {} is private",
token::get_ident(name), struct_desc),
UnnamedField(idx) => format!("field \\#{} of {} is private",
idx + 1, struct_desc),
};
self.tcx.sess.span_err(span, msg);
}
// Given the ID of a method, checks to ensure it's in scope.
fn check_static_method(&mut self, span: Span, method_id: ast::DefId,
name: ast::Ident) {
// If the method is a default method, we need to use the def_id of
// the default implementation.
let method_id = ty::method(self.tcx, method_id).provided_source
.unwrap_or(method_id);
let string = token::get_ident(name);
self.report_error(self.ensure_public(span,
method_id,
None,
format!("method `{}`", string)));
}
// Checks that a path is in scope.
fn check_path(&mut self, span: Span, path_id: ast::NodeId, path: &ast::Path) {
debug!("privacy - path {}", self.nodestr(path_id));
let orig_def = self.tcx.def_map.borrow().get_copy(&path_id);
let ck = |tyname: &str| {
let ck_public = |def: ast::DefId| {
let name = token::get_ident(path.segments
.last()
.unwrap()
.identifier);
let origdid = def_id_of_def(orig_def);
self.ensure_public(span, def, Some(origdid),
format!("{} `{}`", tyname, name))
};
match *self.last_private_map.get(&path_id) {
resolve::LastMod(resolve::AllPublic) => {},
resolve::LastMod(resolve::DependsOn(def)) => {
self.report_error(ck_public(def));
},
resolve::LastImport{value_priv: value_priv,
value_used: check_value,
type_priv: type_priv,
type_used: check_type} => {
// This dance with found_error is because we don't want to report
// a privacy error twice for the same directive.
let found_error = match (type_priv, check_type) {
(Some(resolve::DependsOn(def)), resolve::Used) => {
!self.report_error(ck_public(def))
},
_ => false,
};
if !found_error {
match (value_priv, check_value) {
(Some(resolve::DependsOn(def)), resolve::Used) => {
self.report_error(ck_public(def));
},
_ => {},
}
}
// If an import is not used in either namespace, we still
// want to check that it could be legal. Therefore we check
// in both namespaces and only report an error if both would
// be illegal. We only report one error, even if it is
// illegal to import from both namespaces.
match (value_priv, check_value, type_priv, check_type) {
(Some(p), resolve::Unused, None, _) |
(None, _, Some(p), resolve::Unused) => {
let p = match p {
resolve::AllPublic => None,
resolve::DependsOn(def) => ck_public(def),
};
if p.is_some() {
self.report_error(p);
}
},
(Some(v), resolve::Unused, Some(t), resolve::Unused) => {
let v = match v {
resolve::AllPublic => None,
resolve::DependsOn(def) => ck_public(def),
};
let t = match t {
resolve::AllPublic => None,
resolve::DependsOn(def) => ck_public(def),
};
match (v, t) {
(Some(_), Some(t)) => {
self.report_error(Some(t));
},
_ => {},
}
},
_ => {},
}
},
}
};
// FIXME(#12334) Imports can refer to definitions in both the type and
// value namespaces. The privacy information is aware of this, but the
// def map is not. Therefore the names we work out below will not always
// be accurate and we can get slightly wonky error messages (but type
// checking is always correct).
match self.tcx.def_map.borrow().get_copy(&path_id) {
ast::DefStaticMethod(..) => ck("static method"),
ast::DefFn(..) => ck("function"),
ast::DefStatic(..) => ck("static"),
ast::DefVariant(..) => ck("variant"),
ast::DefTy(..) => ck("type"),
ast::DefTrait(..) => ck("trait"),
ast::DefStruct(..) => ck("struct"),
ast::DefMethod(_, Some(..)) => ck("trait method"),
ast::DefMethod(..) => ck("method"),
ast::DefMod(..) => ck("module"),
_ => {}
}
}
// Checks that a method is in scope.
fn check_method(&mut self, span: Span, origin: MethodOrigin,
ident: ast::Ident) {
match origin {
MethodStatic(method_id) => {
self.check_static_method(span, method_id, ident)
}
// Trait methods are always all public. The only controlling factor
// is whether the trait itself is accessible or not.
MethodParam(MethodParam { trait_id: trait_id, .. }) |
MethodObject(MethodObject { trait_id: trait_id, .. }) => {
self.report_error(self.ensure_public(span, trait_id, None,
"source trait"));
}
}
}
}
impl<'a> Visitor<()> for PrivacyVisitor<'a> {
fn visit_item(&mut self, item: &ast::Item, _: ()) {
// Do not check privacy inside items with the resolve_unexported
// attribute. This is used for the test runner.
if attr::contains_name(item.attrs.as_slice(), "!resolve_unexported") {
return;
}
let orig_curitem = replace(&mut self.curitem, item.id);
visit::walk_item(self, item, ());
self.curitem = orig_curitem;
}
fn visit_expr(&mut self, expr: &ast::Expr, _: ()) {
match expr.node {
ast::ExprField(base, ident, _) => {
match ty::get(ty::expr_ty_adjusted(self.tcx, base)).sty {
ty::ty_struct(id, _) => {
self.check_field(expr.span, id, NamedField(ident));
}
_ => {}
}
}
ast::ExprMethodCall(ident, _, _) => {
let method_call = MethodCall::expr(expr.id);
match self.tcx.method_map.borrow().find(&method_call) {
None => {
self.tcx.sess.span_bug(expr.span,
"method call not in \
method map");
}
Some(method) => {
debug!("(privacy checking) checking impl method");
self.check_method(expr.span, method.origin, ident.node);
}
}
}
ast::ExprStruct(_, ref fields, _) => {
match ty::get(ty::expr_ty(self.tcx, expr)).sty {
ty::ty_struct(id, _) => {
for field in (*fields).iter() {
self.check_field(expr.span, id,
NamedField(field.ident.node));
}
}
ty::ty_enum(_, _) => {
match self.tcx.def_map.borrow().get_copy(&expr.id) {
ast::DefVariant(_, variant_id, _) => {
for field in fields.iter() {
self.check_field(expr.span, variant_id,
NamedField(field.ident.node));
}
}
_ => self.tcx.sess.span_bug(expr.span,
"resolve didn't \
map enum struct \
constructor to a \
variant def"),
}
}
_ => self.tcx.sess.span_bug(expr.span, "struct expr \
didn't have \
struct type?!"),
}
}
ast::ExprPath(..) => {
let guard = |did: ast::DefId| {
let fields = ty::lookup_struct_fields(self.tcx, did);
let any_priv = fields.iter().any(|f| {
f.vis != ast::Public && (
!is_local(f.id) ||
!self.private_accessible(f.id.node))
});
if any_priv {
self.tcx.sess.span_err(expr.span,
"cannot invoke tuple struct constructor \
with private fields");
}
};
match self.tcx.def_map.borrow().find(&expr.id) {
Some(&ast::DefStruct(did)) => {
guard(if is_local(did) {
local_def(self.tcx.map.get_parent(did.node))
} else {
// "tuple structs" with zero fields (such as
// `pub struct Foo;`) don't have a ctor_id, hence
// the unwrap_or to the same struct id.
let maybe_did =
csearch::get_tuple_struct_definition_if_ctor(
&self.tcx.sess.cstore, did);
maybe_did.unwrap_or(did)
})
}
// Tuple struct constructors across crates are identified as
// DefFn types, so we explicitly handle that case here.
Some(&ast::DefFn(did, _)) if !is_local(did) => {
match csearch::get_tuple_struct_definition_if_ctor(
&self.tcx.sess.cstore, did) {
Some(did) => guard(did),
None => {}
}
}
_ => {}
}
}
_ => {}
}
visit::walk_expr(self, expr, ());
}
fn visit_view_item(&mut self, a: &ast::ViewItem, _: ()) {
match a.node {
ast::ViewItemExternCrate(..) => {}
ast::ViewItemUse(ref uses) => {
for vpath in uses.iter() {
match vpath.node {
ast::ViewPathSimple(..) | ast::ViewPathGlob(..) => {}
ast::ViewPathList(_, ref list, _) => {
for pid in list.iter() {
debug!("privacy - list {}", pid.node.id);
let seg = ast::PathSegment {
identifier: pid.node.name,
lifetimes: Vec::new(),
types: OwnedSlice::empty(),
};
let segs = vec!(seg);
let path = ast::Path {
global: false,
span: pid.span,
segments: segs,
};
self.check_path(pid.span, pid.node.id, &path);
}
}
}
}
}
}
visit::walk_view_item(self, a, ());
}
fn visit_pat(&mut self, pattern: &ast::Pat, _: ()) {
// Foreign functions do not have their patterns mapped in the def_map,
// and there's nothing really relevant there anyway, so don't bother
// checking privacy. If you can name the type then you can pass it to an
// external C function anyway.
if self.in_foreign { return }
match pattern.node {
ast::PatStruct(_, ref fields, _) => {
match ty::get(ty::pat_ty(self.tcx, pattern)).sty {
ty::ty_struct(id, _) => {
for field in fields.iter() {
self.check_field(pattern.span, id,
NamedField(field.ident));
}
}
ty::ty_enum(_, _) => {
match self.tcx.def_map.borrow().find(&pattern.id) {
Some(&ast::DefVariant(_, variant_id, _)) => {
for field in fields.iter() {
self.check_field(pattern.span, variant_id,
NamedField(field.ident));
}
}
_ => self.tcx.sess.span_bug(pattern.span,
"resolve didn't \
map enum struct \
pattern to a \
variant def"),
}
}
_ => self.tcx.sess.span_bug(pattern.span,
"struct pattern didn't have \
struct type?!"),
}
}
// Patterns which bind no fields are allowable (the path is check
// elsewhere).
ast::PatEnum(_, Some(ref fields)) => {
match ty::get(ty::pat_ty(self.tcx, pattern)).sty {
ty::ty_struct(id, _) => {
for (i, field) in fields.iter().enumerate() {
match field.node {
ast::PatWild(..) => continue,
_ => {}
}
self.check_field(field.span, id, UnnamedField(i));
}
}
ty::ty_enum(..) => {
// enum fields have no privacy at this time
}
_ => {}
}
}
_ => {}
}
visit::walk_pat(self, pattern, ());
}
fn visit_foreign_item(&mut self, fi: &ast::ForeignItem, _: ()) {
self.in_foreign = true;
visit::walk_foreign_item(self, fi, ());
self.in_foreign = false;
}
fn visit_path(&mut self, path: &ast::Path, id: ast::NodeId, _: ()) {
self.check_path(path.span, id, path);
visit::walk_path(self, path, ());
}
}
////////////////////////////////////////////////////////////////////////////////
/// The privacy sanity check visitor, ensures unnecessary visibility isn't here
////////////////////////////////////////////////////////////////////////////////
struct SanePrivacyVisitor<'a> {
tcx: &'a ty::ctxt,
in_fn: bool,
}
impl<'a> Visitor<()> for SanePrivacyVisitor<'a> {
fn visit_item(&mut self, item: &ast::Item, _: ()) {
if self.in_fn {
self.check_all_inherited(item);
} else {
self.check_sane_privacy(item);
}
let orig_in_fn = replace(&mut self.in_fn, match item.node {
ast::ItemMod(..) => false, // modules turn privacy back on
_ => self.in_fn, // otherwise we inherit
});
visit::walk_item(self, item, ());
self.in_fn = orig_in_fn;
}
fn visit_fn(&mut self, fk: &visit::FnKind, fd: &ast::FnDecl,
b: &ast::Block, s: Span, n: ast::NodeId, _: ()) {
// This catches both functions and methods
let orig_in_fn = replace(&mut self.in_fn, true);
visit::walk_fn(self, fk, fd, b, s, n, ());
self.in_fn = orig_in_fn;
}
fn visit_view_item(&mut self, i: &ast::ViewItem, _: ()) {
match i.vis {
ast::Inherited => {}
ast::Public => {
if self.in_fn {
self.tcx.sess.span_err(i.span, "unnecessary `pub`, imports \
in functions are never \
reachable");
} else {
match i.node {
ast::ViewItemExternCrate(..) => {
self.tcx.sess.span_err(i.span, "`pub` visibility \
is not allowed");
}
_ => {}
}
}
}
}
visit::walk_view_item(self, i, ());
}
}
impl<'a> SanePrivacyVisitor<'a> {
/// Validates all of the visibility qualifiers placed on the item given. This
/// ensures that there are no extraneous qualifiers that don't actually do
/// anything. In theory these qualifiers wouldn't parse, but that may happen
/// later on down the road...
fn check_sane_privacy(&self, item: &ast::Item) {
let tcx = self.tcx;
let check_inherited = |sp: Span, vis: ast::Visibility, note: &str| {
if vis != ast::Inherited {
tcx.sess.span_err(sp, "unnecessary visibility qualifier");
if note.len() > 0 {
tcx.sess.span_note(sp, note);
}
}
};
match item.node {
// implementations of traits don't need visibility qualifiers because
// that's controlled by having the trait in scope.
ast::ItemImpl(_, Some(..), _, ref methods) => {
check_inherited(item.span, item.vis,
"visibility qualifiers have no effect on trait \
impls");
for m in methods.iter() {
check_inherited(m.span, m.vis, "");
}
}
ast::ItemImpl(..) => {
check_inherited(item.span, item.vis,
"place qualifiers on individual methods instead");
}
ast::ItemForeignMod(..) => {
check_inherited(item.span, item.vis,
"place qualifiers on individual functions \
instead");
}
ast::ItemEnum(ref def, _) => {
for v in def.variants.iter() {
match v.node.vis {
ast::Public => {
if item.vis == ast::Public {
tcx.sess.span_err(v.span, "unnecessary `pub` \
visibility");
}
}
ast::Inherited => {}
}
}
}
ast::ItemTrait(_, _, _, ref methods) => {
for m in methods.iter() {
match *m {
ast::Provided(ref m) => {
check_inherited(m.span, m.vis,
"unnecessary visibility");
}
ast::Required(..) => {}
}
}
}
ast::ItemStatic(..) | ast::ItemStruct(..) |
ast::ItemFn(..) | ast::ItemMod(..) | ast::ItemTy(..) |
ast::ItemMac(..) => {}
}
}
/// When inside of something like a function or a method, visibility has no
/// control over anything so this forbids any mention of any visibility
fn check_all_inherited(&self, item: &ast::Item) {
let tcx = self.tcx;
let check_inherited = |sp: Span, vis: ast::Visibility| {
if vis != ast::Inherited {
tcx.sess.span_err(sp, "visibility has no effect inside functions");
}
};
let check_struct = |def: &@ast::StructDef| {
for f in def.fields.iter() {
match f.node.kind {
ast::NamedField(_, p) => check_inherited(f.span, p),
ast::UnnamedField(..) => {}
}
}
};
check_inherited(item.span, item.vis);
match item.node {
ast::ItemImpl(_, _, _, ref methods) => {
for m in methods.iter() {
check_inherited(m.span, m.vis);
}
}
ast::ItemForeignMod(ref fm) => {
for i in fm.items.iter() {
check_inherited(i.span, i.vis);
}
}
ast::ItemEnum(ref def, _) => {
for v in def.variants.iter() {
check_inherited(v.span, v.node.vis);
match v.node.kind {
ast::StructVariantKind(ref s) => check_struct(s),
ast::TupleVariantKind(..) => {}
}
}
}
ast::ItemStruct(ref def, _) => check_struct(def),
ast::ItemTrait(_, _, _, ref methods) => {
for m in methods.iter() {
match *m {
ast::Required(..) => {}
ast::Provided(ref m) => check_inherited(m.span, m.vis),
}
}
}
ast::ItemStatic(..) |
ast::ItemFn(..) | ast::ItemMod(..) | ast::ItemTy(..) |
ast::ItemMac(..) => {}
}
}
}
struct VisiblePrivateTypesVisitor<'a> {
tcx: &'a ty::ctxt,
exported_items: &'a ExportedItems,
public_items: &'a PublicItems,
}
struct CheckTypeForPrivatenessVisitor<'a, 'b> {
inner: &'b VisiblePrivateTypesVisitor<'a>,
/// whether the type refers to private types.
contains_private: bool,
/// whether we've recurred at all (i.e. if we're pointing at the
/// first type on which visit_ty was called).
at_outer_type: bool,
// whether that first type is a public path.
outer_type_is_public_path: bool,
}
impl<'a> VisiblePrivateTypesVisitor<'a> {
fn path_is_private_type(&self, path_id: ast::NodeId) -> bool {
let did = match self.tcx.def_map.borrow().find_copy(&path_id) {
// `int` etc. (None doesn't seem to occur.)
None | Some(ast::DefPrimTy(..)) => return false,
Some(def) => def_id_of_def(def)
};
// A path can only be private if:
// it's in this crate...
is_local(did) &&
// ... it's not exported (obviously) ...
!self.exported_items.contains(&did.node) &&
// .. and it corresponds to a type in the AST (this returns None for
// type parameters)
self.tcx.map.find(did.node).is_some()
}
fn trait_is_public(&self, trait_id: ast::NodeId) -> bool {
// FIXME: this would preferably be using `exported_items`, but all
// traits are exported currently (see `EmbargoVisitor.exported_trait`)
self.public_items.contains(&trait_id)
}
}
impl<'a, 'b> Visitor<()> for CheckTypeForPrivatenessVisitor<'a, 'b> {
fn visit_ty(&mut self, ty: &ast::Ty, _: ()) {
match ty.node {
ast::TyPath(_, _, path_id) => {
if self.inner.path_is_private_type(path_id) {
self.contains_private = true;
// found what we're looking for so let's stop
// working.
return
} else if self.at_outer_type {
self.outer_type_is_public_path = true;
}
}
_ => {}
}
self.at_outer_type = false;
visit::walk_ty(self, ty, ())
}
// don't want to recurse into [, .. expr]
fn visit_expr(&mut self, _: &ast::Expr, _: ()) {}
}
impl<'a> Visitor<()> for VisiblePrivateTypesVisitor<'a> {
fn visit_item(&mut self, item: &ast::Item, _: ()) {
match item.node {
// contents of a private mod can be reexported, so we need
// to check internals.
ast::ItemMod(_) => {}
// An `extern {}` doesn't introduce a new privacy
// namespace (the contents have their own privacies).
ast::ItemForeignMod(_) => {}
ast::ItemTrait(..) if !self.trait_is_public(item.id) => return,
// impls need some special handling to try to offer useful
// error messages without (too many) false positives
// (i.e. we could just return here to not check them at
// all, or some worse estimation of whether an impl is
// publically visible.
ast::ItemImpl(ref g, ref trait_ref, self_, ref methods) => {
// `impl [... for] Private` is never visible.
let self_contains_private;
// impl [... for] Public<...>, but not `impl [... for]
// ~[Public]` or `(Public,)` etc.
let self_is_public_path;
// check the properties of the Self type:
{
let mut visitor = CheckTypeForPrivatenessVisitor {
inner: self,
contains_private: false,
at_outer_type: true,
outer_type_is_public_path: false,
};
visitor.visit_ty(self_, ());
self_contains_private = visitor.contains_private;
self_is_public_path = visitor.outer_type_is_public_path;
}
// miscellaneous info about the impl
// `true` iff this is `impl Private for ...`.
let not_private_trait =
trait_ref.as_ref().map_or(true, // no trait counts as public trait
|tr| {
let did = ty::trait_ref_to_def_id(self.tcx, tr);
!is_local(did) || self.trait_is_public(did.node)
});
// `true` iff this is a trait impl or at least one method is public.
//
// `impl Public { $( fn ...() {} )* }` is not visible.
//
// This is required over just using the methods' privacy
// directly because we might have `impl<T: Foo<Private>> ...`,
// and we shouldn't warn about the generics if all the methods
// are private (because `T` won't be visible externally).
let trait_or_some_public_method =
trait_ref.is_some() ||
methods.iter().any(|m| self.exported_items.contains(&m.id));
if !self_contains_private &&
not_private_trait &&
trait_or_some_public_method {
visit::walk_generics(self, g, ());
match *trait_ref {
None => {
for method in methods.iter() {
visit::walk_method_helper(self, *method, ())
}
}
Some(ref tr) => {
// Any private types in a trait impl fall into two
// categories.
// 1. mentioned in the trait definition
// 2. mentioned in the type params/generics
//
// Those in 1. can only occur if the trait is in
// this crate and will've been warned about on the
// trait definition (there's no need to warn twice
// so we don't check the methods).
//
// Those in 2. are warned via walk_generics and this
// call here.
visit::walk_trait_ref_helper(self, tr, ())
}
}
} else if trait_ref.is_none() && self_is_public_path {
// impl Public<Private> { ... }. Any public static
// methods will be visible as `Public::foo`.
let mut found_pub_static = false;
for method in methods.iter() {
if method.explicit_self.node == ast::SelfStatic &&
self.exported_items.contains(&method.id) {
found_pub_static = true;
visit::walk_method_helper(self, *method, ());
}
}
if found_pub_static {
visit::walk_generics(self, g, ())
}
}
return
}
// `type ... = ...;` can contain private types, because
// we're introducing a new name.
ast::ItemTy(..) => return,
// not at all public, so we don't care
_ if !self.exported_items.contains(&item.id) => return,
_ => {}
}
// we've carefully constructed it so that if we're here, then
// any `visit_ty`'s will be called on things that are in
// public signatures, i.e. things that we're interested in for
// this visitor.
visit::walk_item(self, item, ());
}
fn visit_foreign_item(&mut self, item: &ast::ForeignItem, _: ()) {
if self.exported_items.contains(&item.id) {
visit::walk_foreign_item(self, item, ())
}
}
fn visit_fn(&mut self,
fk: &visit::FnKind, fd: &ast::FnDecl, b: &ast::Block, s: Span, id: ast::NodeId,
_: ()) {
// needs special handling for methods.
if self.exported_items.contains(&id) {
visit::walk_fn(self, fk, fd, b, s, id, ());
}
}
fn visit_ty(&mut self, t: &ast::Ty, _: ()) {
match t.node {
ast::TyPath(ref p, _, path_id) => {
if self.path_is_private_type(path_id) {
self.tcx.sess.add_lint(lint::VisiblePrivateTypes,
path_id, p.span,
"private type in exported type signature".to_owned());
}
}
_ => {}
}
visit::walk_ty(self, t, ())
}
fn visit_variant(&mut self, v: &ast::Variant, g: &ast::Generics, _: ()) {
if self.exported_items.contains(&v.node.id) {
visit::walk_variant(self, v, g, ());
}
}
fn visit_struct_field(&mut self, s: &ast::StructField, _: ()) {
match s.node.kind {
ast::NamedField(_, ast::Public) => {
visit::walk_struct_field(self, s, ());
}
_ => {}
}
}
// we don't need to introspect into these at all: an
// expression/block context can't possibly contain exported
// things, and neither do view_items. (Making them no-ops stops us
// from traversing the whole AST without having to be super
// careful about our `walk_...` calls above.)
fn visit_view_item(&mut self, _: &ast::ViewItem, _: ()) {}
fn visit_block(&mut self, _: &ast::Block, _: ()) {}
fn visit_expr(&mut self, _: &ast::Expr, _: ()) {}
}
pub fn check_crate(tcx: &ty::ctxt,
exp_map2: &resolve::ExportMap2,
external_exports: resolve::ExternalExports,
last_private_map: resolve::LastPrivateMap,
krate: &ast::Crate) -> (ExportedItems, PublicItems) {
// Figure out who everyone's parent is
let mut visitor = ParentVisitor {
parents: NodeMap::new(),
curparent: ast::DUMMY_NODE_ID,
};
visit::walk_crate(&mut visitor, krate, ());
// Use the parent map to check the privacy of everything
let mut visitor = PrivacyVisitor {
curitem: ast::DUMMY_NODE_ID,
in_fn: false,
in_foreign: false,
tcx: tcx,
parents: visitor.parents,
external_exports: external_exports,
last_private_map: last_private_map,
};
visit::walk_crate(&mut visitor, krate, ());
// Sanity check to make sure that all privacy usage and controls are
// reasonable.
let mut visitor = SanePrivacyVisitor {
in_fn: false,
tcx: tcx,
};
visit::walk_crate(&mut visitor, krate, ());
tcx.sess.abort_if_errors();
// Build up a set of all exported items in the AST. This is a set of all
// items which are reachable from external crates based on visibility.
let mut visitor = EmbargoVisitor {
tcx: tcx,
exported_items: NodeSet::new(),
public_items: NodeSet::new(),
reexports: NodeSet::new(),
exp_map2: exp_map2,
prev_exported: true,
prev_public: true,
};
loop {
let before = visitor.exported_items.len();
visit::walk_crate(&mut visitor, krate, ());
if before == visitor.exported_items.len() {
break
}
}
let EmbargoVisitor { exported_items, public_items, .. } = visitor;
{
let mut visitor = VisiblePrivateTypesVisitor {
tcx: tcx,
exported_items: &exported_items,
public_items: &public_items
};
visit::walk_crate(&mut visitor, krate, ());
}
return (exported_items, public_items);
}