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Rollup merge of rust-lang#62103 - RalfJung:debug-assert, r=alexcrichton
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Add debug assertions to write_bytes and copy*

Looks like @nitnelave  went MIA in rust-lang#58783, so I am re-submitting their PR, tweaked just a bit. I took care to preserve commit authorship.

Cc rust-lang#53871
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@Mark-Simulacrum
Mark-Simulacrum authored Jul 15, 2019
2 parents 4b65a86 + 85d76a1 commit f940617
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Showing 6 changed files with 57 additions and 23 deletions.
38 changes: 19 additions & 19 deletions Cargo.lock
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Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ dependencies = [
name = "alloc"
version = "0.0.0"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
"rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
"rand_xorshift 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
Expand Down Expand Up @@ -131,7 +131,7 @@ dependencies = [
"autocfg 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
"backtrace-sys 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
"cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-demangle 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-core 1.0.0",
Expand All @@ -143,7 +143,7 @@ version = "0.1.27"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-core 1.0.0",
]
Expand Down Expand Up @@ -373,7 +373,7 @@ name = "cfg-if"
version = "0.1.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-core 1.0.0",
]

Expand Down Expand Up @@ -502,7 +502,7 @@ dependencies = [

[[package]]
name = "compiler_builtins"
version = "0.1.16"
version = "0.1.17"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
Expand Down Expand Up @@ -834,7 +834,7 @@ name = "dlmalloc"
version = "0.1.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-core 1.0.0",
]
Expand Down Expand Up @@ -1008,7 +1008,7 @@ name = "fortanix-sgx-abi"
version = "0.3.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-core 1.0.0",
]

Expand Down Expand Up @@ -1199,7 +1199,7 @@ name = "hashbrown"
version = "0.4.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-alloc 1.0.0",
"rustc-std-workspace-core 1.0.0",
]
Expand Down Expand Up @@ -2066,7 +2066,7 @@ dependencies = [
name = "panic_abort"
version = "0.0.0"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
"libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
]
Expand All @@ -2077,7 +2077,7 @@ version = "0.0.0"
dependencies = [
"alloc 0.0.0",
"cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
"libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
"unwind 0.0.0",
Expand Down Expand Up @@ -2263,7 +2263,7 @@ name = "profiler_builtins"
version = "0.0.0"
dependencies = [
"cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
]

Expand Down Expand Up @@ -2835,7 +2835,7 @@ name = "rustc-demangle"
version = "0.1.15"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"rustc-std-workspace-core 1.0.0",
]

Expand Down Expand Up @@ -2941,7 +2941,7 @@ dependencies = [
"alloc 0.0.0",
"build_helper 0.1.0",
"cmake 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
]

Expand Down Expand Up @@ -3160,7 +3160,7 @@ dependencies = [
"alloc 0.0.0",
"build_helper 0.1.0",
"cmake 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
]

Expand Down Expand Up @@ -3223,7 +3223,7 @@ dependencies = [
"alloc 0.0.0",
"build_helper 0.1.0",
"cmake 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
]

Expand Down Expand Up @@ -3341,7 +3341,7 @@ dependencies = [
"alloc 0.0.0",
"build_helper 0.1.0",
"cmake 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
]

Expand Down Expand Up @@ -3648,7 +3648,7 @@ dependencies = [
"backtrace 0.3.29 (registry+https://github.com/rust-lang/crates.io-index)",
"cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
"cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
"dlmalloc 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
"fortanix-sgx-abi 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
Expand Down Expand Up @@ -4309,7 +4309,7 @@ version = "0.0.0"
dependencies = [
"cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
"cfg-if 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
"compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
"core 0.0.0",
"libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
]
Expand Down Expand Up @@ -4527,7 +4527,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
"checksum colored 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b0aa3473e85a3161b59845d6096b289bb577874cafeaf75ea1b1beaa6572c7fc"
"checksum commoncrypto 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d056a8586ba25a1e4d61cb090900e495952c7886786fc55f909ab2f819b69007"
"checksum commoncrypto-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1fed34f46747aa73dfaa578069fd8279d2818ade2b55f38f22a9401c7f4083e2"
"checksum compiler_builtins 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "e79ed19793c99771b386d76e08c3419409bb3d418b81a8b8afc73524247461cf"
"checksum compiler_builtins 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)" = "ad9b4731b9e701aefe9e6bd1e9173f30526661508f9aaadaa5caec25ddf95585"
"checksum compiletest_rs 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)" = "f40ecc9332b68270998995c00f8051ee856121764a0d3230e64c9efd059d27b6"
"checksum constant_time_eq 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8ff012e225ce166d4422e0e78419d901719760f62ae2b7969ca6b564d1b54a9e"
"checksum core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4e2640d6d0bf22e82bed1b73c6aef8d5dd31e5abe6666c57e6d45e2649f4f887"
Expand Down
33 changes: 32 additions & 1 deletion src/libcore/intrinsics.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,8 @@
issue = "0")]
#![allow(missing_docs)]

use crate::mem;

#[stable(feature = "drop_in_place", since = "1.8.0")]
#[rustc_deprecated(reason = "no longer an intrinsic - use `ptr::drop_in_place` directly",
since = "1.18.0")]
Expand Down Expand Up @@ -1323,6 +1325,26 @@ extern "rust-intrinsic" {
// (`transmute` also falls into this category, but it cannot be wrapped due to the
// check that `T` and `U` have the same size.)

/// Checks whether `ptr` is properly aligned with respect to
/// `align_of::<T>()`.
pub(crate) fn is_aligned_and_not_null<T>(ptr: *const T) -> bool {
!ptr.is_null() && ptr as usize % mem::align_of::<T>() == 0
}

/// Checks whether the regions of memory starting at `src` and `dst` of size
/// `count * size_of::<T>()` overlap.
fn overlaps<T>(src: *const T, dst: *const T, count: usize) -> bool {
let src_usize = src as usize;
let dst_usize = dst as usize;
let size = mem::size_of::<T>().checked_mul(count).unwrap();
let diff = if src_usize > dst_usize {
src_usize - dst_usize
} else {
dst_usize - src_usize
};
size > diff
}

/// Copies `count * size_of::<T>()` bytes from `src` to `dst`. The source
/// and destination must *not* overlap.
///
Expand Down Expand Up @@ -1412,7 +1434,11 @@ pub unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize) {
extern "rust-intrinsic" {
fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
}
copy_nonoverlapping(src, dst, count);

debug_assert!(is_aligned_and_not_null(src), "attempt to copy from unaligned or null pointer");
debug_assert!(is_aligned_and_not_null(dst), "attempt to copy to unaligned or null pointer");
debug_assert!(!overlaps(src, dst, count), "attempt to copy to overlapping memory");
copy_nonoverlapping(src, dst, count)
}

/// Copies `count * size_of::<T>()` bytes from `src` to `dst`. The source
Expand Down Expand Up @@ -1472,6 +1498,9 @@ pub unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
extern "rust-intrinsic" {
fn copy<T>(src: *const T, dst: *mut T, count: usize);
}

debug_assert!(is_aligned_and_not_null(src), "attempt to copy from unaligned or null pointer");
debug_assert!(is_aligned_and_not_null(dst), "attempt to copy to unaligned or null pointer");
copy(src, dst, count)
}

Expand Down Expand Up @@ -1553,5 +1582,7 @@ pub unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize) {
extern "rust-intrinsic" {
fn write_bytes<T>(dst: *mut T, val: u8, count: usize);
}

debug_assert!(is_aligned_and_not_null(dst), "attempt to write to unaligned or null pointer");
write_bytes(dst, val, count)
}
6 changes: 3 additions & 3 deletions src/libcore/slice/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@
use crate::cmp::Ordering::{self, Less, Equal, Greater};
use crate::cmp;
use crate::fmt;
use crate::intrinsics::{assume, exact_div, unchecked_sub};
use crate::intrinsics::{assume, exact_div, unchecked_sub, is_aligned_and_not_null};
use crate::isize;
use crate::iter::*;
use crate::ops::{FnMut, Try, self};
Expand Down Expand Up @@ -5228,7 +5228,7 @@ unsafe impl<'a, T> TrustedRandomAccess for RChunksExactMut<'a, T> {
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T] {
debug_assert!(data as usize % mem::align_of::<T>() == 0, "attempt to create unaligned slice");
debug_assert!(is_aligned_and_not_null(data), "attempt to create unaligned or null slice");
debug_assert!(mem::size_of::<T>().saturating_mul(len) <= isize::MAX as usize,
"attempt to create slice covering half the address space");
&*ptr::slice_from_raw_parts(data, len)
Expand All @@ -5249,7 +5249,7 @@ pub unsafe fn from_raw_parts<'a, T>(data: *const T, len: usize) -> &'a [T] {
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
pub unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a mut [T] {
debug_assert!(data as usize % mem::align_of::<T>() == 0, "attempt to create unaligned slice");
debug_assert!(is_aligned_and_not_null(data), "attempt to create unaligned or null slice");
debug_assert!(mem::size_of::<T>().saturating_mul(len) <= isize::MAX as usize,
"attempt to create slice covering half the address space");
&mut *ptr::slice_from_raw_parts_mut(data, len)
Expand Down
1 change: 1 addition & 0 deletions src/test/codegen/issue-45222.rs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
// compile-flags: -O
// ignore-debug: the debug assertions get in the way

#![crate_type = "lib"]

Expand Down
1 change: 1 addition & 0 deletions src/test/codegen/issue-45466.rs
View file
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
// compile-flags: -O
// ignore-debug: the debug assertions get in the way

#![crate_type="rlib"]

Expand Down
1 change: 1 addition & 0 deletions src/test/codegen/swap-small-types.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
// compile-flags: -O
// only-x86_64
// ignore-debug: the debug assertions get in the way

#![crate_type = "lib"]

Expand Down

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