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librustc: Redo the unsafe checker and make unsafe methods not callable from safe code

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This commit is contained in:
Patrick Walton 2013-05-23 19:12:16 -07:00
parent b5da389d36
commit aeda178011
16 changed files with 288 additions and 136 deletions
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18
src/libextra/arc.rs
View File

@ -198,13 +198,15 @@ pub impl<T:Owned> MutexARC<T> {
*/
#[inline(always)]
unsafe fn access<U>(&self, blk: &fn(x: &mut T) -> U) -> U {
let state = self.x.get();
// Borrowck would complain about this if the function were
// not already unsafe. See borrow_rwlock, far below.
do (&(*state).lock).lock {
check_poison(true, (*state).failed);
let _z = PoisonOnFail(&mut (*state).failed);
blk(&mut (*state).data)
unsafe {
let state = self.x.get();
// Borrowck would complain about this if the function were
// not already unsafe. See borrow_rwlock, far below.
do (&(*state).lock).lock {
check_poison(true, (*state).failed);
let _z = PoisonOnFail(&mut (*state).failed);
blk(&mut (*state).data)
}
}
}
@ -356,8 +358,8 @@ fn write_cond<'x, 'c, U>(&self,
* access modes, this will not poison the ARC.
*/
fn read<U>(&self, blk: &fn(x: &T) -> U) -> U {
let state = self.x.get();
unsafe {
let state = self.x.get();
do (*state).lock.read {
check_poison(false, (*state).failed);
blk(&(*state).data)

94
src/libextra/sync.rs
View File

@ -100,30 +100,34 @@ fn new_sem_and_signal(count: int, num_condvars: uint)
#[doc(hidden)]
pub impl<Q:Owned> Sem<Q> {
fn acquire(&self) {
let mut waiter_nobe = None;
do (**self).with |state| {
state.count -= 1;
if state.count < 0 {
// Create waiter nobe.
let (WaitEnd, SignalEnd) = comm::oneshot();
// Tell outer scope we need to block.
waiter_nobe = Some(WaitEnd);
// Enqueue ourself.
state.waiters.tail.send(SignalEnd);
unsafe {
let mut waiter_nobe = None;
do (**self).with |state| {
state.count -= 1;
if state.count < 0 {
// Create waiter nobe.
let (WaitEnd, SignalEnd) = comm::oneshot();
// Tell outer scope we need to block.
waiter_nobe = Some(WaitEnd);
// Enqueue ourself.
state.waiters.tail.send(SignalEnd);
}
}
// Uncomment if you wish to test for sem races. Not valgrind-friendly.
/* for 1000.times { task::yield(); } */
// Need to wait outside the exclusive.
if waiter_nobe.is_some() {
let _ = comm::recv_one(waiter_nobe.unwrap());
}
}
// Uncomment if you wish to test for sem races. Not valgrind-friendly.
/* for 1000.times { task::yield(); } */
// Need to wait outside the exclusive.
if waiter_nobe.is_some() {
let _ = comm::recv_one(waiter_nobe.unwrap());
}
}
fn release(&self) {
do (**self).with |state| {
state.count += 1;
if state.count <= 0 {
signal_waitqueue(&state.waiters);
unsafe {
do (**self).with |state| {
state.count += 1;
if state.count <= 0 {
signal_waitqueue(&state.waiters);
}
}
}
}
@ -283,17 +287,19 @@ fn signal(&self) -> bool { self.signal_on(0) }
/// As signal, but with a specified condvar_id. See wait_on.
fn signal_on(&self, condvar_id: uint) -> bool {
let mut out_of_bounds = None;
let mut result = false;
do (**self.sem).with |state| {
if condvar_id < state.blocked.len() {
result = signal_waitqueue(&state.blocked[condvar_id]);
} else {
out_of_bounds = Some(state.blocked.len());
unsafe {
let mut out_of_bounds = None;
let mut result = false;
do (**self.sem).with |state| {
if condvar_id < state.blocked.len() {
result = signal_waitqueue(&state.blocked[condvar_id]);
} else {
out_of_bounds = Some(state.blocked.len());
}
}
do check_cvar_bounds(out_of_bounds, condvar_id, "cond.signal_on()") {
result
}
}
do check_cvar_bounds(out_of_bounds, condvar_id, "cond.signal_on()") {
result
}
}
@ -304,20 +310,22 @@ fn broadcast(&self) -> uint { self.broadcast_on(0) }
fn broadcast_on(&self, condvar_id: uint) -> uint {
let mut out_of_bounds = None;
let mut queue = None;
do (**self.sem).with |state| {
if condvar_id < state.blocked.len() {
// To avoid :broadcast_heavy, we make a new waitqueue,
// swap it out with the old one, and broadcast on the
// old one outside of the little-lock.
queue = Some(util::replace(&mut state.blocked[condvar_id],
new_waitqueue()));
} else {
out_of_bounds = Some(state.blocked.len());
unsafe {
do (**self.sem).with |state| {
if condvar_id < state.blocked.len() {
// To avoid :broadcast_heavy, we make a new waitqueue,
// swap it out with the old one, and broadcast on the
// old one outside of the little-lock.
queue = Some(util::replace(&mut state.blocked[condvar_id],
new_waitqueue()));
} else {
out_of_bounds = Some(state.blocked.len());
}
}
do check_cvar_bounds(out_of_bounds, condvar_id, "cond.signal_on()") {
let queue = queue.swap_unwrap();
broadcast_waitqueue(&queue)
}
}
do check_cvar_bounds(out_of_bounds, condvar_id, "cond.signal_on()") {
let queue = queue.swap_unwrap();
broadcast_waitqueue(&queue)
}
}
}

3
src/librustc/driver/driver.rs
View File

@ -262,6 +262,9 @@ pub fn compile_rest(sess: Session,
time(time_passes, ~"privacy checking", ||
middle::privacy::check_crate(ty_cx, &method_map, crate));
time(time_passes, ~"effect checking", ||
middle::effect::check_crate(ty_cx, method_map, crate));
time(time_passes, ~"loop checking", ||
middle::check_loop::check_crate(ty_cx, crate));

154
src/librustc/middle/effect.rs Normal file
View File

@ -0,0 +1,154 @@
// 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.
//! Enforces the Rust effect system. Currently there is just one effect,
/// `unsafe`.
use middle::ty::{ty_bare_fn, ty_closure, ty_ptr};
use middle::ty;
use middle::typeck::method_map;
use util::ppaux;
use syntax::ast::{deref, expr_call, expr_inline_asm, expr_method_call};
use syntax::ast::{expr_unary, node_id, unsafe_blk, unsafe_fn};
use syntax::ast;
use syntax::codemap::span;
use syntax::visit::{fk_item_fn, fk_method};
use syntax::visit;
#[deriving(Eq)]
enum UnsafeContext {
SafeContext,
UnsafeFn,
UnsafeBlock(node_id),
}
struct Context {
/// The method map.
method_map: method_map,
/// Whether we're in an unsafe context.
unsafe_context: UnsafeContext,
}
fn type_is_unsafe_function(ty: ty::t) -> bool {
match ty::get(ty).sty {
ty_bare_fn(ref f) => f.purity == unsafe_fn,
ty_closure(ref f) => f.purity == unsafe_fn,
_ => false,
}
}
pub fn check_crate(tcx: ty::ctxt,
method_map: method_map,
crate: @ast::crate) {
let context = @mut Context {
method_map: method_map,
unsafe_context: SafeContext,
};
let require_unsafe: @fn(span: span,
description: &str) = |span, description| {
match context.unsafe_context {
SafeContext => {
// Report an error.
tcx.sess.span_err(span,
fmt!("%s requires unsafe function or block",
description))
}
UnsafeBlock(block_id) => {
// OK, but record this.
debug!("effect: recording unsafe block as used: %?", block_id);
let _ = tcx.used_unsafe.insert(block_id);
}
UnsafeFn => {}
}
};
let visitor = visit::mk_vt(@visit::Visitor {
visit_fn: |fn_kind, fn_decl, block, span, node_id, _, visitor| {
let is_unsafe_fn = match *fn_kind {
fk_item_fn(_, _, purity, _) => purity == unsafe_fn,
fk_method(_, _, method) => method.purity == unsafe_fn,
_ => false,
};
let old_unsafe_context = context.unsafe_context;
if is_unsafe_fn {
context.unsafe_context = UnsafeFn
}
visit::visit_fn(fn_kind,
fn_decl,
block,
span,
node_id,
(),
visitor);
context.unsafe_context = old_unsafe_context
},
visit_block: |block, _, visitor| {
let old_unsafe_context = context.unsafe_context;
if block.node.rules == unsafe_blk {
context.unsafe_context = UnsafeBlock(block.node.id)
}
visit::visit_block(block, (), visitor);
context.unsafe_context = old_unsafe_context
},
visit_expr: |expr, _, visitor| {
match expr.node {
expr_method_call(*) => {
let base_type = ty::node_id_to_type(tcx, expr.callee_id);
debug!("effect: method call case, base type is %s",
ppaux::ty_to_str(tcx, base_type));
if type_is_unsafe_function(base_type) {
require_unsafe(expr.span,
"invocation of unsafe method")
}
}
expr_call(base, _, _) => {
let base_type = ty::node_id_to_type(tcx, base.id);
debug!("effect: call case, base type is %s",
ppaux::ty_to_str(tcx, base_type));
if type_is_unsafe_function(base_type) {
require_unsafe(expr.span, "call to unsafe function")
}
}
expr_unary(deref, base) => {
let base_type = ty::node_id_to_type(tcx, base.id);
debug!("effect: unary case, base type is %s",
ppaux::ty_to_str(tcx, base_type));
match ty::get(base_type).sty {
ty_ptr(_) => {
require_unsafe(expr.span,
"dereference of unsafe pointer")
}
_ => {}
}
}
expr_inline_asm(*) => {
require_unsafe(expr.span, "use of inline assembly")
}
_ => {}
}
visit::visit_expr(expr, (), visitor)
},
.. *visit::default_visitor()
});
visit::visit_crate(crate, (), visitor)
}

34
src/librustc/middle/typeck/check/mod.rs
View File

@ -891,21 +891,6 @@ fn mk_subr(&self,
infer::mk_subr(self.infcx(), a_is_expected, span, sub, sup)
}
fn require_unsafe(&self, sp: span, op: ~str) {
match self.ps.purity {
ast::unsafe_fn => {
// ok, but flag that we used the source of unsafeness
debug!("flagging %? as a used unsafe source", self.ps);
self.tcx().used_unsafe.insert(self.ps.def);
}
_ => {
self.ccx.tcx.sess.span_err(
sp,
fmt!("%s requires unsafe function or block", op));
}
}
}
fn with_region_lb<R>(@mut self, lb: ast::node_id, f: &fn() -> R) -> R {
let old_region_lb = self.region_lb;
self.region_lb = lb;
@ -2285,16 +2270,6 @@ fn check_loop_body(fcx: @mut FnCtxt,
}
ast::deref => {
let sty = structure_of(fcx, expr.span, oprnd_t);
match sty {
// deref'ing an unsafe pointer requires that we be in
// an unsafe context
ty::ty_ptr(*) => {
fcx.require_unsafe(
expr.span,
~"dereference of unsafe pointer");
}
_ => { /*ok*/ }
}
let operand_ty = ty::deref_sty(tcx, &sty, true);
match operand_ty {
Some(mt) => {
@ -2392,8 +2367,6 @@ fn check_loop_body(fcx: @mut FnCtxt,
fcx.write_ty(id, ty_param_bounds_and_ty.ty);
}
ast::expr_inline_asm(ref ia) => {
fcx.require_unsafe(expr.span, ~"use of inline assembly");
for ia.inputs.each |&(_, in)| {
check_expr(fcx, in);
}
@ -3223,13 +3196,6 @@ pub fn ty_param_bounds_and_ty_for_def(fcx: @mut FnCtxt,
};
}
ast::def_fn(id, ast::unsafe_fn) |
ast::def_static_method(id, _, ast::unsafe_fn) => {
// Unsafe functions can only be touched in an unsafe context
fcx.require_unsafe(sp, ~"access to unsafe function");
return ty::lookup_item_type(fcx.ccx.tcx, id);
}
ast::def_fn(id, _) | ast::def_static_method(id, _, _) |
ast::def_const(id) | ast::def_variant(_, id) |
ast::def_struct(id) => {

1
src/librustc/rustc.rc
View File

@ -109,6 +109,7 @@ pub mod middle {
pub mod privacy;
pub mod moves;
pub mod entry;
pub mod effect;
}
pub mod front {

20
src/libstd/comm.rs
View File

@ -236,20 +236,24 @@ pub fn new(c: Chan<T>) -> SharedChan<T> {
impl<T: Owned> GenericChan<T> for SharedChan<T> {
fn send(&self, x: T) {
let mut xx = Some(x);
do self.ch.with_imm |chan| {
let x = replace(&mut xx, None);
chan.send(x.unwrap())
unsafe {
let mut xx = Some(x);
do self.ch.with_imm |chan| {
let x = replace(&mut xx, None);
chan.send(x.unwrap())
}
}
}
}
impl<T: Owned> GenericSmartChan<T> for SharedChan<T> {
fn try_send(&self, x: T) -> bool {
let mut xx = Some(x);
do self.ch.with_imm |chan| {
let x = replace(&mut xx, None);
chan.try_send(x.unwrap())
unsafe {
let mut xx = Some(x);
do self.ch.with_imm |chan| {
let x = replace(&mut xx, None);
chan.try_send(x.unwrap())
}
}
}
}

24
src/libstd/os.rs
View File

@ -861,20 +861,18 @@ pub fn change_dir_locked(p: &Path, action: &fn()) -> bool {
fn key(_: Exclusive<()>) { }
let result = unsafe {
global_data_clone_create(key, || {
~exclusive(())
})
};
unsafe {
let result = global_data_clone_create(key, || { ~exclusive(()) });
do result.with_imm() |_| {
let old_dir = os::getcwd();
if change_dir(p) {
action();
change_dir(&old_dir)
}
else {
false
do result.with_imm() |_| {
let old_dir = os::getcwd();
if change_dir(p) {
action();
change_dir(&old_dir)
}
else {
false
}
}
}
}

18
src/libstd/rt/message_queue.rs
View File

@ -29,16 +29,20 @@ pub fn new() -> MessageQueue<T> {
}
pub fn push(&mut self, value: T) {
let value = Cell(value);
self.queue.with(|q| q.push(value.take()) );
unsafe {
let value = Cell(value);
self.queue.with(|q| q.push(value.take()) );
}
}
pub fn pop(&mut self) -> Option<T> {
do self.queue.with |q| {
if !q.is_empty() {
Some(q.shift())
} else {
None
unsafe {
do self.queue.with |q| {
if !q.is_empty() {
Some(q.shift())
} else {
None
}
}
}
}

34
src/libstd/rt/work_queue.rs
View File

@ -29,32 +29,40 @@ fn new() -> WorkQueue<T> {
}
fn push(&mut self, value: T) {
let value = Cell(value);
self.queue.with(|q| q.unshift(value.take()) );
unsafe {
let value = Cell(value);
self.queue.with(|q| q.unshift(value.take()) );
}
}
fn pop(&mut self) -> Option<T> {
do self.queue.with |q| {
if !q.is_empty() {
Some(q.shift())
} else {
None
unsafe {
do self.queue.with |q| {
if !q.is_empty() {
Some(q.shift())
} else {
None
}
}
}
}
fn steal(&mut self) -> Option<T> {
do self.queue.with |q| {
if !q.is_empty() {
Some(q.pop())
} else {
None
unsafe {
do self.queue.with |q| {
if !q.is_empty() {
Some(q.pop())
} else {
None
}
}
}
}
fn is_empty(&self) -> bool {
self.queue.with_imm(|q| q.is_empty() )
unsafe {
self.queue.with_imm(|q| q.is_empty() )
}
}
}

8
src/libstd/task/spawn.rs
View File

@ -159,13 +159,17 @@ struct AncestorNode {
// Accessors for taskgroup arcs and ancestor arcs that wrap the unsafety.
#[inline(always)]
fn access_group<U>(x: &TaskGroupArc, blk: &fn(TaskGroupInner) -> U) -> U {
x.with(blk)
unsafe {
x.with(blk)
}
}
#[inline(always)]
fn access_ancestors<U>(x: &Exclusive<AncestorNode>,
blk: &fn(x: &mut AncestorNode) -> U) -> U {
x.with(blk)
unsafe {
x.with(blk)
}
}
// Iterates over an ancestor list.

2
src/test/compile-fail/foreign-unsafe-fn-called.rs
View File

@ -19,5 +19,5 @@ mod test {
fn main() {
test::free();
//~^ ERROR access to unsafe function requires unsafe function or block
//~^ ERROR call to unsafe function requires unsafe function or block
}

2
src/test/compile-fail/foreign-unsafe-fn.rs
View File

@ -19,5 +19,5 @@ mod test {
fn main() {
let x = test::free;
//~^ ERROR access to unsafe function requires unsafe function or block
//~^ ERROR call to unsafe function requires unsafe function or block
}

6
src/test/compile-fail/forget-init-unsafe.rs
View File

@ -12,6 +12,6 @@
// Test that the `forget` and `init` intrinsics are really unsafe
pub fn main() {
let stuff = init::<int>(); //~ ERROR access to unsafe function requires unsafe
forget(stuff); //~ ERROR access to unsafe function requires unsafe
}
let stuff = init::<int>(); //~ ERROR call to unsafe function requires unsafe
forget(stuff); //~ ERROR call to unsafe function requires unsafe
}

2
src/test/compile-fail/unsafe-fn-called-from-safe.rs
View File

@ -13,5 +13,5 @@
unsafe fn f() { return; }
fn main() {
f(); //~ ERROR access to unsafe function requires unsafe function or block
f(); //~ ERROR call to unsafe function requires unsafe function or block
}

4
src/test/compile-fail/unsafe-fn-used-as-value.rs
View File

@ -13,6 +13,6 @@
unsafe fn f() { return; }
fn main() {
let x = f; //~ ERROR access to unsafe function requires unsafe function or block
x();
let x = f;
x(); //~ ERROR call to unsafe function requires unsafe function or block
}