Skip to content

Commit

Permalink
Unify all validity check intrinsics
Browse files Browse the repository at this point in the history
Also merges the inhabitedness check into the query to further unify the
code paths.
  • Loading branch information
Nilstrieb committed Feb 27, 2023
1 parent 49b9cc5 commit 5f593da
Show file tree
Hide file tree
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
Loading

0 comments on commit 5f593da

Please sign in to comment.