nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2025-04-28 11:07:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fixes issue 39827: ICE in volatile_store intrinsic

Browse Source 
- adds handling of zero-sized types for volatile_store.
- adds type size checks and warnigns for other volatile intrinsics.
- adds a test to check warnings emitting.

Cause of the issue

While preparing for trans_intrinsic_call() invoke arguments are
processed with trans_argument() method which excludes zero-sized types
from argument list (to be more correct - all arguments for which
ArgKind is Ignore are filtered out). As result volatile_store() intrinsic
gets one argument instead of expected address and value.

How it is fixed

Modification of the trans_argument() method may cause side effects,
therefore change was implemented in volatile_store() intrinsic building
code itself. Now it checks function signature and if it was specialised
with zero-sized type, then emits C_nil() instead of accessing
non-existing second argument.

Additionally warnings are added for all volatile operations which are
specialised with zero-sized arguments. In fact, those operations are omitted
in LLVM backend if no memory affected at all, e.g. number of elements
is zero or type is zero-sized. This was not explicitly documented before
and could lead to potential issues if developer expects volatile behaviour,
but type has degraded to zero-sized.
This commit is contained in:
Alexey Tarasov 2017-08-12 18:42:44 +10:00
parent 2fa5340318
commit 0cd358742d
3 changed files with 158 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
src/librustc_trans/intrinsic.rs
View File

@ -83,6 +83,38 @@ fn get_simple_intrinsic(ccx: &CrateContext, name: &str) -> Option<ValueRef> {
Some(ccx.get_intrinsic(&llvm_name))
}
fn warn_if_size_is_weird<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
tp_ty: Ty<'tcx>,
count: ValueRef,
span: Span,
name: &str) {
let ccx = bcx.ccx;
let lltp_ty = type_of::type_of(ccx, tp_ty);
let ty_size = machine::llsize_of(ccx, lltp_ty);
let total = const_to_uint( bcx.mul(ty_size, count) );
if total > 0 {
return;
}
let text = format!("suspicious monomorphization of `{}` intrinsic", name);
let note = match name
{
"volatile_load" | "volatile_store" =>
format!("'{}' was specialized with zero-sized type '{}'",
name, tp_ty),
_ => format!("'{}' was specialized with type '{}', number of \
elements is {}",
name, tp_ty,
const_to_uint(count))
};
let sess = bcx.sess();
sess.struct_span_warn(span, &text)
.note(&note)
.emit();
}
/// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
/// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
/// add them to librustc_trans/trans/context.rs
@ -217,17 +249,24 @@ pub fn trans_intrinsic_call<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
}
"volatile_copy_nonoverlapping_memory" => {
copy_intrinsic(bcx, false, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
let tp_ty = substs.type_at(0);
warn_if_size_is_weird(bcx, tp_ty, llargs[2], span, name);
copy_intrinsic(bcx, false, true, tp_ty, llargs[0], llargs[1], llargs[2])
}
"volatile_copy_memory" => {
copy_intrinsic(bcx, true, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
let tp_ty = substs.type_at(0);
warn_if_size_is_weird(bcx, tp_ty, llargs[2], span, name);
copy_intrinsic(bcx, true, true, tp_ty, llargs[0], llargs[1], llargs[2])
}
"volatile_set_memory" => {
memset_intrinsic(bcx, true, substs.type_at(0), llargs[0], llargs[1], llargs[2])
let tp_ty = substs.type_at(0);
warn_if_size_is_weird(bcx, tp_ty, llargs[2], span, name);
memset_intrinsic(bcx, true, tp_ty, llargs[0], llargs[1], llargs[2])
}
"volatile_load" => {
let tp_ty = substs.type_at(0);
let mut ptr = llargs[0];
warn_if_size_is_weird(bcx, tp_ty, C_uint(ccx,1usize), span, name);
if let Some(ty) = fn_ty.ret.cast {
ptr = bcx.pointercast(ptr, ty.ptr_to());
}
@ -239,6 +278,7 @@ pub fn trans_intrinsic_call<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
},
"volatile_store" => {
let tp_ty = substs.type_at(0);
warn_if_size_is_weird(bcx, tp_ty, C_uint(ccx,1usize), span, name);
if type_is_fat_ptr(bcx.ccx, tp_ty) {
bcx.volatile_store(llargs[1], get_dataptr(bcx, llargs[0]));
bcx.volatile_store(llargs[2], get_meta(bcx, llargs[0]));
@ -246,7 +286,11 @@ pub fn trans_intrinsic_call<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
let val = if fn_ty.args[1].is_indirect() {
bcx.load(llargs[1], None)
} else {
from_immediate(bcx, llargs[1])
if !type_is_zero_size(ccx, tp_ty) {
from_immediate(bcx, llargs[1])
} else {
C_nil(ccx)
}
};
let ptr = bcx.pointercast(llargs[0], val_ty(val).ptr_to());
let store = bcx.volatile_store(val, ptr);

37
src/test/ui/issue-39827.rs Normal file
View File

@ -0,0 +1,37 @@
// Copyright 2017 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.
#![feature(core_intrinsics)]
use std::intrinsics::{ volatile_copy_memory, volatile_store, volatile_load,
volatile_copy_nonoverlapping_memory,
volatile_set_memory };
fn main () {
let mut dst_pair = (1, 2);
let src_pair = (3, 4);
let mut dst_empty = ();
let src_empty = ();
const COUNT_0: usize = 0;
const COUNT_100: usize = 100;
unsafe {
volatile_copy_memory(&mut dst_pair, &dst_pair, COUNT_0);
volatile_copy_nonoverlapping_memory(&mut dst_pair, &src_pair, 0);
volatile_copy_memory(&mut dst_empty, &dst_empty, 100);
volatile_copy_nonoverlapping_memory(&mut dst_empty, &src_empty,
COUNT_100);
volatile_set_memory(&mut dst_empty, 0, COUNT_100);
volatile_set_memory(&mut dst_pair, 0, COUNT_0);
volatile_store(&mut dst_empty, ());
volatile_store(&mut dst_empty, src_empty);
volatile_load(&src_empty);
}
}

73
src/test/ui/issue-39827.stderr Normal file
View File

@ -0,0 +1,73 @@
warning: suspicious monomorphization of `volatile_copy_memory` intrinsic
--> $DIR/issue-39827.rs:26:9
|
26 | volatile_copy_memory(&mut dst_pair, &dst_pair, COUNT_0);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_copy_memory' was specialized with type '(i32, i32)', number of elements is 0
warning: suspicious monomorphization of `volatile_copy_nonoverlapping_memory` intrinsic
--> $DIR/issue-39827.rs:27:9
|
27 | volatile_copy_nonoverlapping_memory(&mut dst_pair, &src_pair, 0);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_copy_nonoverlapping_memory' was specialized with type '(i32, i32)', number of elements is 0
warning: suspicious monomorphization of `volatile_copy_memory` intrinsic
--> $DIR/issue-39827.rs:28:9
|
28 | volatile_copy_memory(&mut dst_empty, &dst_empty, 100);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_copy_memory' was specialized with type '()', number of elements is 100
warning: suspicious monomorphization of `volatile_copy_nonoverlapping_memory` intrinsic
--> $DIR/issue-39827.rs:29:9
|
29 | / volatile_copy_nonoverlapping_memory(&mut dst_empty, &src_empty,
30 | | COUNT_100);
| |______________________________________________________^
|
= note: 'volatile_copy_nonoverlapping_memory' was specialized with type '()', number of elements is 100
warning: suspicious monomorphization of `volatile_set_memory` intrinsic
--> $DIR/issue-39827.rs:31:9
|
31 | volatile_set_memory(&mut dst_empty, 0, COUNT_100);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_set_memory' was specialized with type '()', number of elements is 100
warning: suspicious monomorphization of `volatile_set_memory` intrinsic
--> $DIR/issue-39827.rs:32:9
|
32 | volatile_set_memory(&mut dst_pair, 0, COUNT_0);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_set_memory' was specialized with type '(i32, i32)', number of elements is 0
warning: suspicious monomorphization of `volatile_store` intrinsic
--> $DIR/issue-39827.rs:33:9
|
33 | volatile_store(&mut dst_empty, ());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_store' was specialized with zero-sized type '()'
warning: suspicious monomorphization of `volatile_store` intrinsic
--> $DIR/issue-39827.rs:34:9
|
34 | volatile_store(&mut dst_empty, src_empty);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_store' was specialized with zero-sized type '()'
warning: suspicious monomorphization of `volatile_load` intrinsic
--> $DIR/issue-39827.rs:35:9
|
35 | volatile_load(&src_empty);
| ^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: 'volatile_load' was specialized with zero-sized type '()'