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Rollup merge of rust-lang#69954 - RalfJung:panic_if-assert, r=Centril…
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…,eddyb

rename panic_if_ intrinsics to assert_

[Suggested by @eddyb](rust-lang/miri#1222 (comment))
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Centril committed Mar 13, 2020
2 parents 2567efc + f61fb53 commit 11ddf3a
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Showing 5 changed files with 36 additions and 18 deletions.
10 changes: 8 additions & 2 deletions src/libcore/intrinsics.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1005,17 +1005,23 @@ extern "rust-intrinsic" {

/// A guard for unsafe functions that cannot ever be executed if `T` is uninhabited:
/// This will statically either panic, or do nothing.
#[cfg(bootstrap)]
pub fn panic_if_uninhabited<T>();

/// A guard for unsafe functions that cannot ever be executed if `T` is uninhabited:
/// This will statically either panic, or do nothing.
#[cfg(not(bootstrap))]
pub fn assert_inhabited<T>();

/// A guard for unsafe functions that cannot ever be executed if `T` does not permit
/// zero-initialization: This will statically either panic, or do nothing.
#[cfg(not(bootstrap))]
pub fn panic_if_zero_invalid<T>();
pub fn assert_zero_valid<T>();

/// A guard for unsafe functions that cannot ever be executed if `T` has invalid
/// bit patterns: This will statically either panic, or do nothing.
#[cfg(not(bootstrap))]
pub fn panic_if_any_invalid<T>();
pub fn assert_uninit_valid<T>();

/// Gets a reference to a static `Location` indicating where it was called.
#[rustc_const_unstable(feature = "const_caller_location", issue = "47809")]
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12 changes: 12 additions & 0 deletions src/libcore/mem/maybe_uninit.rs
Original file line number Diff line number Diff line change
Expand Up @@ -495,7 +495,10 @@ impl<T> MaybeUninit<T> {
#[inline(always)]
#[rustc_diagnostic_item = "assume_init"]
pub unsafe fn assume_init(self) -> T {
#[cfg(bootstrap)]
intrinsics::panic_if_uninhabited::<T>();
#[cfg(not(bootstrap))]
intrinsics::assert_inhabited::<T>();
ManuallyDrop::into_inner(self.value)
}

Expand Down Expand Up @@ -559,7 +562,10 @@ impl<T> MaybeUninit<T> {
#[unstable(feature = "maybe_uninit_extra", issue = "63567")]
#[inline(always)]
pub unsafe fn read(&self) -> T {
#[cfg(bootstrap)]
intrinsics::panic_if_uninhabited::<T>();
#[cfg(not(bootstrap))]
intrinsics::assert_inhabited::<T>();
self.as_ptr().read()
}

Expand Down Expand Up @@ -621,7 +627,10 @@ impl<T> MaybeUninit<T> {
#[unstable(feature = "maybe_uninit_ref", issue = "63568")]
#[inline(always)]
pub unsafe fn get_ref(&self) -> &T {
#[cfg(bootstrap)]
intrinsics::panic_if_uninhabited::<T>();
#[cfg(not(bootstrap))]
intrinsics::assert_inhabited::<T>();
&*self.value
}

Expand Down Expand Up @@ -739,7 +748,10 @@ impl<T> MaybeUninit<T> {
#[unstable(feature = "maybe_uninit_ref", issue = "63568")]
#[inline(always)]
pub unsafe fn get_mut(&mut self) -> &mut T {
#[cfg(bootstrap)]
intrinsics::panic_if_uninhabited::<T>();
#[cfg(not(bootstrap))]
intrinsics::assert_inhabited::<T>();
&mut *self.value
}

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4 changes: 2 additions & 2 deletions src/libcore/mem/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -497,7 +497,7 @@ pub const fn needs_drop<T>() -> bool {
#[rustc_diagnostic_item = "mem_zeroed"]
pub unsafe fn zeroed<T>() -> T {
#[cfg(not(bootstrap))]
intrinsics::panic_if_zero_invalid::<T>();
intrinsics::assert_zero_valid::<T>();
#[cfg(bootstrap)]
intrinsics::panic_if_uninhabited::<T>();
intrinsics::init()
Expand Down Expand Up @@ -533,7 +533,7 @@ pub unsafe fn zeroed<T>() -> T {
#[rustc_diagnostic_item = "mem_uninitialized"]
pub unsafe fn uninitialized<T>() -> T {
#[cfg(not(bootstrap))]
intrinsics::panic_if_any_invalid::<T>();
intrinsics::assert_uninit_valid::<T>();
#[cfg(bootstrap)]
intrinsics::panic_if_uninhabited::<T>();
intrinsics::uninit()
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26 changes: 13 additions & 13 deletions src/librustc_codegen_ssa/mir/block.rs
Original file line number Diff line number Diff line change
Expand Up @@ -449,38 +449,38 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
destination: &Option<(mir::Place<'tcx>, mir::BasicBlock)>,
cleanup: Option<mir::BasicBlock>,
) -> bool {
// Emit a panic or a no-op for `panic_if_uninhabited`.
// Emit a panic or a no-op for `assert_*` intrinsics.
// These are intrinsics that compile to panics so that we can get a message
// which mentions the offending type, even from a const context.
#[derive(Debug, PartialEq)]
enum PanicIntrinsic {
IfUninhabited,
IfZeroInvalid,
IfAnyInvalid,
enum AssertIntrinsic {
Inhabited,
ZeroValid,
UninitValid,
};
let panic_intrinsic = intrinsic.and_then(|i| match i {
// FIXME: Move to symbols instead of strings.
"panic_if_uninhabited" => Some(PanicIntrinsic::IfUninhabited),
"panic_if_zero_invalid" => Some(PanicIntrinsic::IfZeroInvalid),
"panic_if_any_invalid" => Some(PanicIntrinsic::IfAnyInvalid),
"assert_inhabited" => Some(AssertIntrinsic::Inhabited),
"assert_zero_valid" => Some(AssertIntrinsic::ZeroValid),
"assert_uninit_valid" => Some(AssertIntrinsic::UninitValid),
_ => None,
});
if let Some(intrinsic) = panic_intrinsic {
use PanicIntrinsic::*;
use AssertIntrinsic::*;
let ty = instance.unwrap().substs.type_at(0);
let layout = bx.layout_of(ty);
let do_panic = match intrinsic {
IfUninhabited => layout.abi.is_uninhabited(),
Inhabited => layout.abi.is_uninhabited(),
// We unwrap as the error type is `!`.
IfZeroInvalid => !layout.might_permit_raw_init(bx, /*zero:*/ true).unwrap(),
ZeroValid => !layout.might_permit_raw_init(bx, /*zero:*/ true).unwrap(),
// We unwrap as the error type is `!`.
IfAnyInvalid => !layout.might_permit_raw_init(bx, /*zero:*/ false).unwrap(),
UninitValid => !layout.might_permit_raw_init(bx, /*zero:*/ false).unwrap(),
};
if do_panic {
let msg_str = if layout.abi.is_uninhabited() {
// Use this error even for the other intrinsics as it is more precise.
format!("attempted to instantiate uninhabited type `{}`", ty)
} else if intrinsic == IfZeroInvalid {
} else if intrinsic == ZeroValid {
format!("attempted to zero-initialize type `{}`, which is invalid", ty)
} else {
format!("attempted to leave type `{}` uninitialized, which is invalid", ty)
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2 changes: 1 addition & 1 deletion src/librustc_typeck/check/intrinsic.rs
Original file line number Diff line number Diff line change
Expand Up @@ -147,7 +147,7 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
),
"rustc_peek" => (1, vec![param(0)], param(0)),
"caller_location" => (0, vec![], tcx.caller_location_ty()),
"panic_if_uninhabited" | "panic_if_zero_invalid" | "panic_if_any_invalid" => {
"assert_inhabited" | "assert_zero_valid" | "assert_uninit_valid" => {
(1, Vec::new(), tcx.mk_unit())
}
"init" => (1, Vec::new(), param(0)),
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