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Unify all validity check intrinsics
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Also merges the inhabitedness check into the query to further unify the
code paths.
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Noratrieb committed Feb 27, 2023
1 parent 49b9cc5 commit 5f593da
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Showing 11 changed files with 119 additions and 163 deletions.
80 changes: 31 additions & 49 deletions compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,7 @@ pub(crate) use cpuid::codegen_cpuid_call;
pub(crate) use llvm::codegen_llvm_intrinsic_call;

use rustc_middle::ty;
use rustc_middle::ty::layout::{HasParamEnv, InitKind};
use rustc_middle::ty::layout::{HasParamEnv, ValidityRequirement};
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::subst::SubstsRef;
use rustc_span::symbol::{kw, sym, Symbol};
Expand Down Expand Up @@ -628,57 +628,39 @@ fn codegen_regular_intrinsic_call<'tcx>(
intrinsic_args!(fx, args => (); intrinsic);

let ty = substs.type_at(0);
let layout = fx.layout_of(ty);
if layout.abi.is_uninhabited() {
with_no_trimmed_paths!({
crate::base::codegen_panic_nounwind(
fx,
&format!("attempted to instantiate uninhabited type `{}`", layout.ty),
source_info,
)
});
return;
}

if intrinsic == sym::assert_zero_valid
&& !fx
.tcx
.check_validity_of_init((InitKind::Zero, fx.param_env().and(ty)))
.expect("expected to have layout during codegen")
{
with_no_trimmed_paths!({
crate::base::codegen_panic_nounwind(
fx,
&format!(
"attempted to zero-initialize type `{}`, which is invalid",
layout.ty
),
source_info,
);
});
return;
}
let requirement = ValidityRequirement::from_intrinsic(intrinsic);

if intrinsic == sym::assert_mem_uninitialized_valid
&& !fx
if let Some(requirement) = requirement {
let do_panic = !fx
.tcx
.check_validity_of_init((
InitKind::UninitMitigated0x01Fill,
fx.param_env().and(ty),
))
.expect("expected to have layout during codegen")
{
with_no_trimmed_paths!({
crate::base::codegen_panic_nounwind(
fx,
&format!(
"attempted to leave type `{}` uninitialized, which is invalid",
layout.ty
),
source_info,
)
});
return;
.check_validity_requirement((requirement, fx.param_env().and(ty)))
.expect("expect to have layout during codegen");

if do_panic {
let layout = fx.layout_of(ty);

with_no_trimmed_paths!({
crate::base::codegen_panic_nounwind(
fx,
&if layout.abi.is_uninhabited() {
format!("attempted to instantiate uninhabited type `{}`", layout.ty)
} else if requirement == ValidityRequirement::Zero {
format!(
"attempted to zero-initialize type `{}`, which is invalid",
layout.ty
)
} else {
format!(
"attempted to leave type `{}` uninitialized, which is invalid",
layout.ty
)
},
source_info,
)
});
return;
}
}
}

Expand Down
42 changes: 11 additions & 31 deletions compiler/rustc_codegen_ssa/src/mir/block.rs
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
use rustc_hir::lang_items::LangItem;
use rustc_index::vec::Idx;
use rustc_middle::mir::{self, AssertKind, SwitchTargets};
use rustc_middle::ty::layout::{HasTyCtxt, InitKind, LayoutOf};
use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement};
use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
use rustc_middle::ty::{self, Instance, Ty, TypeVisitableExt};
use rustc_session::config::OptLevel;
Expand Down Expand Up @@ -655,44 +655,24 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
// 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 AssertIntrinsic {
Inhabited,
ZeroValid,
MemUninitializedValid,
}
let panic_intrinsic = intrinsic.and_then(|i| match i {
sym::assert_inhabited => Some(AssertIntrinsic::Inhabited),
sym::assert_zero_valid => Some(AssertIntrinsic::ZeroValid),
sym::assert_mem_uninitialized_valid => Some(AssertIntrinsic::MemUninitializedValid),
_ => None,
});
if let Some(intrinsic) = panic_intrinsic {
use AssertIntrinsic::*;

let panic_intrinsic = intrinsic.and_then(|s| ValidityRequirement::from_intrinsic(s));
if let Some(requirement) = panic_intrinsic {
let ty = instance.unwrap().substs.type_at(0);

let do_panic = !bx
.tcx()
.check_validity_requirement((requirement, bx.param_env().and(ty)))
.expect("expect to have layout during codegen");

let layout = bx.layout_of(ty);
let do_panic = match intrinsic {
Inhabited => layout.abi.is_uninhabited(),
ZeroValid => !bx
.tcx()
.check_validity_of_init((InitKind::Zero, bx.param_env().and(ty)))
.expect("expected to have layout during codegen"),
MemUninitializedValid => !bx
.tcx()
.check_validity_of_init((
InitKind::UninitMitigated0x01Fill,
bx.param_env().and(ty),
))
.expect("expected to have layout during codegen"),
};

Some(if do_panic {
let msg_str = with_no_visible_paths!({
with_no_trimmed_paths!({
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 == ZeroValid {
} else if requirement == ValidityRequirement::Zero {
format!("attempted to zero-initialize type `{}`, which is invalid", ty)
} else {
format!(
Expand Down
74 changes: 26 additions & 48 deletions compiler/rustc_const_eval/src/interpret/intrinsics.rs
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ use rustc_middle::mir::{
BinOp, NonDivergingIntrinsic,
};
use rustc_middle::ty;
use rustc_middle::ty::layout::{InitKind, LayoutOf as _};
use rustc_middle::ty::layout::{LayoutOf as _, ValidityRequirement};
use rustc_middle::ty::subst::SubstsRef;
use rustc_middle::ty::{Ty, TyCtxt};
use rustc_span::symbol::{sym, Symbol};
Expand Down Expand Up @@ -418,57 +418,35 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
| sym::assert_zero_valid
| sym::assert_mem_uninitialized_valid => {
let ty = instance.substs.type_at(0);
let layout = self.layout_of(ty)?;

// For *all* intrinsics we first check `is_uninhabited` to give a more specific
// error message.
if layout.abi.is_uninhabited() {
// The run-time intrinsic panics just to get a good backtrace; here we abort
// since there is no problem showing a backtrace even for aborts.
M::abort(
self,
format!(
let requirement = ValidityRequirement::from_intrinsic(intrinsic_name).unwrap();

let should_panic = !self
.tcx
.check_validity_requirement((requirement, self.param_env.and(ty)))
.map_err(|_| err_inval!(TooGeneric))?;

if should_panic {
let layout = self.layout_of(ty)?;

let msg = match requirement {
// For *all* intrinsics we first check `is_uninhabited` to give a more specific
// error message.
_ if layout.abi.is_uninhabited() => format!(
"aborted execution: attempted to instantiate uninhabited type `{}`",
ty
),
)?;
}

if intrinsic_name == sym::assert_zero_valid {
let should_panic = !self
.tcx
.check_validity_of_init((InitKind::Zero, self.param_env.and(ty)))
.map_err(|_| err_inval!(TooGeneric))?;

if should_panic {
M::abort(
self,
format!(
"aborted execution: attempted to zero-initialize type `{}`, which is invalid",
ty
),
)?;
}
}
ValidityRequirement::Inhabited => bug!("handled earlier"),
ValidityRequirement::Zero => format!(
"aborted execution: attempted to zero-initialize type `{}`, which is invalid",
ty
),
ValidityRequirement::UninitMitigated0x01Fill => format!(
"aborted execution: attempted to leave type `{}` uninitialized, which is invalid",
ty
),
};

if intrinsic_name == sym::assert_mem_uninitialized_valid {
let should_panic = !self
.tcx
.check_validity_of_init((
InitKind::UninitMitigated0x01Fill,
self.param_env.and(ty),
))
.map_err(|_| err_inval!(TooGeneric))?;

if should_panic {
M::abort(
self,
format!(
"aborted execution: attempted to leave type `{}` uninitialized, which is invalid",
ty
),
)?;
}
M::abort(self, msg)?;
}
}
sym::simd_insert => {
Expand Down
4 changes: 2 additions & 2 deletions compiler/rustc_const_eval/src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@ pub fn provide(providers: &mut Providers) {
let (param_env, value) = param_env_and_value.into_parts();
const_eval::deref_mir_constant(tcx, param_env, value)
};
providers.check_validity_of_init = |tcx, (init_kind, param_env_and_ty)| {
util::might_permit_raw_init(tcx, init_kind, param_env_and_ty)
providers.check_validity_requirement = |tcx, (init_kind, param_env_and_ty)| {
util::check_validity_requirement(tcx, init_kind, param_env_and_ty)
};
}
Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
use rustc_middle::ty::layout::{InitKind, LayoutCx, LayoutError, LayoutOf, TyAndLayout};
use rustc_middle::ty::layout::{LayoutCx, LayoutError, LayoutOf, TyAndLayout, ValidityRequirement};
use rustc_middle::ty::{ParamEnv, ParamEnvAnd, Ty, TyCtxt};
use rustc_session::Limit;
use rustc_target::abi::{Abi, FieldsShape, Scalar, Variants};
Expand All @@ -18,16 +18,23 @@ use crate::interpret::{InterpCx, MemoryKind, OpTy};
/// Rust UB as long as there is no risk of miscompilations. The `strict_init_checks` can be set to
/// do a full check against Rust UB instead (in which case we will also ignore the 0x01-filling and
/// to the full uninit check).
pub fn might_permit_raw_init<'tcx>(
pub fn check_validity_requirement<'tcx>(
tcx: TyCtxt<'tcx>,
kind: InitKind,
kind: ValidityRequirement,
param_env_and_ty: ParamEnvAnd<'tcx, Ty<'tcx>>,
) -> Result<bool, LayoutError<'tcx>> {
let layout = tcx.layout_of(param_env_and_ty)?;

// There is nothing strict or lax about inhabitedness.
if kind == ValidityRequirement::Inhabited {
return Ok(!layout.abi.is_uninhabited());
}

if tcx.sess.opts.unstable_opts.strict_init_checks {
might_permit_raw_init_strict(tcx.layout_of(param_env_and_ty)?, tcx, kind)
might_permit_raw_init_strict(layout, tcx, kind)
} else {
let layout_cx = LayoutCx { tcx, param_env: param_env_and_ty.param_env };
might_permit_raw_init_lax(tcx.layout_of(param_env_and_ty)?, &layout_cx, kind)
might_permit_raw_init_lax(layout, &layout_cx, kind)
}
}

Expand All @@ -36,7 +43,7 @@ pub fn might_permit_raw_init<'tcx>(
fn might_permit_raw_init_strict<'tcx>(
ty: TyAndLayout<'tcx>,
tcx: TyCtxt<'tcx>,
kind: InitKind,
kind: ValidityRequirement,
) -> Result<bool, LayoutError<'tcx>> {
let machine = CompileTimeInterpreter::new(
Limit::new(0),
Expand All @@ -50,7 +57,7 @@ fn might_permit_raw_init_strict<'tcx>(
.allocate(ty, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap))
.expect("OOM: failed to allocate for uninit check");

if kind == InitKind::Zero {
if kind == ValidityRequirement::Zero {
cx.write_bytes_ptr(
allocated.ptr,
std::iter::repeat(0_u8).take(ty.layout.size().bytes_usize()),
Expand All @@ -72,15 +79,18 @@ fn might_permit_raw_init_strict<'tcx>(
fn might_permit_raw_init_lax<'tcx>(
this: TyAndLayout<'tcx>,
cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
init_kind: InitKind,
init_kind: ValidityRequirement,
) -> Result<bool, LayoutError<'tcx>> {
let scalar_allows_raw_init = move |s: Scalar| -> bool {
match init_kind {
InitKind::Zero => {
ValidityRequirement::Inhabited => {
bug!("ValidityRequirement::Inhabited should have been handled above")
}
ValidityRequirement::Zero => {
// The range must contain 0.
s.valid_range(cx).contains(0)
}
InitKind::UninitMitigated0x01Fill => {
ValidityRequirement::UninitMitigated0x01Fill => {
// The range must include an 0x01-filled buffer.
let mut val: u128 = 0x01;
for _ in 1..s.size(cx).bytes() {
Expand Down
4 changes: 2 additions & 2 deletions compiler/rustc_const_eval/src/util/mod.rs
Original file line number Diff line number Diff line change
@@ -1,14 +1,14 @@
mod alignment;
mod call_kind;
mod check_validity_requirement;
pub mod collect_writes;
mod compare_types;
mod find_self_call;
mod might_permit_raw_init;
mod type_name;

pub use self::alignment::is_disaligned;
pub use self::call_kind::{call_kind, CallDesugaringKind, CallKind};
pub use self::check_validity_requirement::check_validity_requirement;
pub use self::compare_types::{is_equal_up_to_subtyping, is_subtype};
pub use self::find_self_call::find_self_call;
pub use self::might_permit_raw_init::might_permit_raw_init;
pub use self::type_name::type_name;
4 changes: 2 additions & 2 deletions compiler/rustc_middle/src/query/keys.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ use crate::infer::canonical::Canonical;
use crate::mir;
use crate::traits;
use crate::ty::fast_reject::SimplifiedType;
use crate::ty::layout::{InitKind, TyAndLayout};
use crate::ty::layout::{TyAndLayout, ValidityRequirement};
use crate::ty::subst::{GenericArg, SubstsRef};
use crate::ty::{self, Ty, TyCtxt};
use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
Expand Down Expand Up @@ -698,7 +698,7 @@ impl Key for HirId {
}
}

impl<'tcx> Key for (InitKind, ty::ParamEnvAnd<'tcx, Ty<'tcx>>) {
impl<'tcx> Key for (ValidityRequirement, ty::ParamEnvAnd<'tcx, Ty<'tcx>>) {
type CacheSelector = DefaultCacheSelector<Self>;

// Just forward to `Ty<'tcx>`
Expand Down
4 changes: 2 additions & 2 deletions compiler/rustc_middle/src/query/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -2173,8 +2173,8 @@ rustc_queries! {
separate_provide_extern
}

query check_validity_of_init(key: (InitKind, ty::ParamEnvAnd<'tcx, Ty<'tcx>>)) -> Result<bool, ty::layout::LayoutError<'tcx>> {
desc { "checking to see if `{}` permits being left {}", key.1.value, key.0 }
query check_validity_requirement(key: (ValidityRequirement, ty::ParamEnvAnd<'tcx, Ty<'tcx>>)) -> Result<bool, ty::layout::LayoutError<'tcx>> {
desc { "checking validity requirement for `{}`: {}", key.1.value, key.0 }
}

query compare_impl_const(
Expand Down
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