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Completely deny calling functions with const conditions in MIR const check unless const_trait_impl is enabled

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This will help us make sure that we never leak any conditionally const
functions into stable.
This commit is contained in:
Michael Goulet 2024-10-30 18:47:54 +00:00
parent e319838e8d
commit 57f2e12f4a
13 changed files with 132 additions and 44 deletions
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29
compiler/rustc_const_eval/src/check_consts/check.rs
View File

@ -363,7 +363,7 @@ fn place_may_escape(&mut self, place: &Place<'_>) -> bool {
}
fn revalidate_conditional_constness(
&self,
&mut self,
callee: DefId,
callee_args: ty::GenericArgsRef<'tcx>,
call_source: CallSource,
@ -374,11 +374,24 @@ fn revalidate_conditional_constness(
return;
}
let const_conditions = tcx.const_conditions(callee).instantiate(tcx, callee_args);
// If there are any const conditions on this fn and `const_trait_impl`
// is not enabled, simply bail. We shouldn't be able to call conditionally
// const functions on stable.
if !const_conditions.is_empty() && !tcx.features().const_trait_impl() {
self.check_op(ops::FnCallNonConst {
callee,
args: callee_args,
span: call_span,
call_source,
feature: Some(sym::const_trait_impl),
});
return;
}
let infcx = tcx.infer_ctxt().build(self.body.typing_mode(tcx));
let ocx = ObligationCtxt::new_with_diagnostics(&infcx);
let const_conditions = tcx.const_conditions(callee).instantiate(tcx, callee_args);
let body_id = self.body.source.def_id().expect_local();
let host_polarity = match self.const_kind() {
hir::ConstContext::ConstFn => ty::BoundConstness::Maybe,
@ -621,7 +634,6 @@ fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location
};
let ConstCx { tcx, body, param_env, .. } = *self.ccx;
let caller = self.def_id();
let fn_ty = func.ty(body, tcx);
@ -639,12 +651,7 @@ fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location
}
};
self.revalidate_conditional_constness(
callee,
fn_args,
call_source,
terminator.source_info.span,
);
self.revalidate_conditional_constness(callee, fn_args, call_source, *fn_span);
let mut is_trait = false;
// Attempting to call a trait method?
@ -684,7 +691,6 @@ fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location
None
};
self.check_op(ops::FnCallNonConst {
caller,
callee,
args: fn_args,
span: *fn_span,
@ -774,7 +780,6 @@ fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location
// Trait functions are not `const fn` so we have to skip them here.
if !tcx.is_const_fn(callee) && !is_trait {
self.check_op(ops::FnCallNonConst {
caller,
callee,
args: fn_args,
span: *fn_span,

11
compiler/rustc_const_eval/src/check_consts/ops.rs
View File

@ -1,6 +1,5 @@
//! Concrete error types for all operations which may be invalid in a certain const context.
use hir::def_id::LocalDefId;
use hir::{ConstContext, LangItem};
use rustc_errors::Diag;
use rustc_errors::codes::*;
@ -74,7 +73,6 @@ fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> Diag<'tcx> {
/// A function call where the callee is not marked as `const`.
#[derive(Debug, Clone, Copy)]
pub(crate) struct FnCallNonConst<'tcx> {
pub caller: LocalDefId,
pub callee: DefId,
pub args: GenericArgsRef<'tcx>,
pub span: Span,
@ -87,8 +85,9 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
#[allow(rustc::diagnostic_outside_of_impl)]
#[allow(rustc::untranslatable_diagnostic)]
fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, _: Span) -> Diag<'tcx> {
let FnCallNonConst { caller, callee, args, span, call_source, feature } = *self;
let ConstCx { tcx, param_env, body, .. } = *ccx;
let FnCallNonConst { callee, args, span, call_source, feature } = *self;
let ConstCx { tcx, param_env, .. } = *ccx;
let caller = ccx.def_id();
let diag_trait = |err, self_ty: Ty<'_>, trait_id| {
let trait_ref = TraitRef::from_method(tcx, trait_id, args);
@ -116,7 +115,7 @@ fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, _: Span) -> Diag<'tcx> {
let obligation =
Obligation::new(tcx, ObligationCause::dummy(), param_env, trait_ref);
let infcx = tcx.infer_ctxt().build(body.typing_mode(tcx));
let infcx = tcx.infer_ctxt().build(ccx.body.typing_mode(tcx));
let mut selcx = SelectionContext::new(&infcx);
let implsrc = selcx.select(&obligation);
@ -289,7 +288,7 @@ macro_rules! error {
if let Some(feature) = feature {
ccx.tcx.disabled_nightly_features(
&mut err,
body.source.def_id().as_local().map(|local| ccx.tcx.local_def_id_to_hir_id(local)),
Some(ccx.tcx.local_def_id_to_hir_id(caller)),
[(String::new(), feature)],
);
}

10
tests/ui/traits/const-traits/const-drop-fail-2.stderr
View File

@ -29,6 +29,12 @@ LL | const fn check<T: ~const Destruct>(_: T) {}
| |
| the destructor for this type cannot be evaluated in constant functions
error[E0277]: the trait bound `T: ~const A` is not satisfied
--> $DIR/const-drop-fail-2.rs:41:9
|
LL | T::a();
| ^^^^^^
error[E0015]: cannot call non-const fn `<T as A>::a` in constant functions
--> $DIR/const-drop-fail-2.rs:41:9
|
@ -41,7 +47,7 @@ help: add `#![feature(effects)]` to the crate attributes to enable
LL + #![feature(effects)]
|
error: aborting due to 5 previous errors
error: aborting due to 6 previous errors
Some errors have detailed explanations: E0015, E0493.
Some errors have detailed explanations: E0015, E0277, E0493.
For more information about an error, try `rustc --explain E0015`.

8
tests/ui/traits/const-traits/const-drop.precise.stderr
View File

@ -78,6 +78,12 @@ error[E0493]: destructor of `T` cannot be evaluated at compile-time
LL | const fn a<T: ~const Destruct>(_: T) {}
| ^ the destructor for this type cannot be evaluated in constant functions
error[E0277]: the trait bound `T: ~const SomeTrait` is not satisfied
--> $DIR/const-drop.rs:69:13
|
LL | T::foo();
| ^^^^^^^^
error[E0015]: cannot call non-const fn `<T as SomeTrait>::foo` in constant functions
--> $DIR/const-drop.rs:69:13
|
@ -90,7 +96,7 @@ help: add `#![feature(effects)]` to the crate attributes to enable
LL + #![feature(effects)]
|
error: aborting due to 10 previous errors
error: aborting due to 11 previous errors
Some errors have detailed explanations: E0015, E0277, E0493.
For more information about an error, try `rustc --explain E0015`.

8
tests/ui/traits/const-traits/const-drop.stock.stderr
View File

@ -80,6 +80,12 @@ LL | const fn a<T: ~const Destruct>(_: T) {}
| |
| the destructor for this type cannot be evaluated in constant functions
error[E0277]: the trait bound `T: ~const SomeTrait` is not satisfied
--> $DIR/const-drop.rs:69:13
|
LL | T::foo();
| ^^^^^^^^
error[E0015]: cannot call non-const fn `<T as SomeTrait>::foo` in constant functions
--> $DIR/const-drop.rs:69:13
|
@ -92,7 +98,7 @@ help: add `#![feature(effects)]` to the crate attributes to enable
LL + #![feature(effects)]
|
error: aborting due to 10 previous errors
error: aborting due to 11 previous errors
Some errors have detailed explanations: E0015, E0277, E0493.
For more information about an error, try `rustc --explain E0015`.

7
tests/ui/traits/const-traits/cross-crate.rs
View File

@ -18,10 +18,11 @@ const fn const_context() {
#[cfg(any(stocknc, gatednc))]
NonConst.func();
//[stocknc]~^ ERROR: cannot call
//[stocknc,gatednc]~^^ ERROR: the trait bound
//[stocknc]~| ERROR: cannot call
//[gatednc]~^^^ ERROR: the trait bound
Const.func();
//[stock]~^ ERROR: cannot call
//[stocknc]~^^ ERROR: cannot call
//[stock,stocknc]~^ ERROR: cannot call
//[stock,stocknc]~| ERROR: cannot call
}
fn main() {}

17
tests/ui/traits/const-traits/cross-crate.stock.stderr
View File

@ -1,5 +1,5 @@
error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
--> $DIR/cross-crate.rs:22:11
--> $DIR/cross-crate.rs:23:11
|
LL | Const.func();
| ^^^^^^
@ -10,6 +10,19 @@ help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
LL + #![feature(const_trait_impl)]
|
error: aborting due to 1 previous error
error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
--> $DIR/cross-crate.rs:23:11
|
LL | Const.func();
| ^^^^^^
|
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
LL + #![feature(const_trait_impl)]
|
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0015`.

39
tests/ui/traits/const-traits/cross-crate.stocknc.stderr
View File

@ -1,9 +1,3 @@
error[E0277]: the trait bound `cross_crate::NonConst: ~const cross_crate::MyTrait` is not satisfied
--> $DIR/cross-crate.rs:19:5
|
LL | NonConst.func();
| ^^^^^^^^^^^^^^^
error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
--> $DIR/cross-crate.rs:19:14
|
@ -16,8 +10,21 @@ help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
LL + #![feature(const_trait_impl)]
|
error[E0015]: cannot call non-const fn `<cross_crate::NonConst as cross_crate::MyTrait>::func` in constant functions
--> $DIR/cross-crate.rs:19:14
|
LL | NonConst.func();
| ^^^^^^
|
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
LL + #![feature(const_trait_impl)]
|
error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
--> $DIR/cross-crate.rs:22:11
--> $DIR/cross-crate.rs:23:11
|
LL | Const.func();
| ^^^^^^
@ -28,7 +35,19 @@ help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
LL + #![feature(const_trait_impl)]
|
error: aborting due to 3 previous errors
error[E0015]: cannot call non-const fn `<cross_crate::Const as cross_crate::MyTrait>::func` in constant functions
--> $DIR/cross-crate.rs:23:11
|
LL | Const.func();
| ^^^^^^
|
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
LL + #![feature(const_trait_impl)]
|
Some errors have detailed explanations: E0015, E0277.
For more information about an error, try `rustc --explain E0015`.
error: aborting due to 4 previous errors
For more information about this error, try `rustc --explain E0015`.

5
tests/ui/traits/const-traits/default-method-body-is-const-body-checking.rs
View File

@ -1,6 +1,3 @@
//@ known-bug: #110395
//@ check-pass
#![feature(const_trait_impl)]
#[const_trait]
@ -13,7 +10,7 @@ const fn foo<T>() where T: ~const Tr {}
pub trait Foo {
fn foo() {
foo::<()>();
//FIXME ~^ ERROR the trait bound `(): Tr` is not satisfied
//~^ ERROR the trait bound `(): ~const Tr` is not satisfied
}
}

15
tests/ui/traits/const-traits/default-method-body-is-const-body-checking.stderr Normal file
View File

@ -0,0 +1,15 @@
error[E0277]: the trait bound `(): ~const Tr` is not satisfied
--> $DIR/default-method-body-is-const-body-checking.rs:12:9
|
LL | foo::<()>();
| ^^^^^^^^^^^
|
note: required by a bound in `foo`
--> $DIR/default-method-body-is-const-body-checking.rs:7:28
|
LL | const fn foo<T>() where T: ~const Tr {}
| ^^^^^^ required by this bound in `foo`
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0277`.

11
tests/ui/traits/const-traits/specializing-constness-2.stderr
View File

@ -1,3 +1,9 @@
error[E0277]: the trait bound `T: ~const A` is not satisfied
--> $DIR/specializing-constness-2.rs:27:5
|
LL | <T as A>::a();
| ^^^^^^^^^^^^^
error[E0015]: cannot call non-const fn `<T as A>::a` in constant functions
--> $DIR/specializing-constness-2.rs:27:5
|
@ -10,6 +16,7 @@ help: add `#![feature(effects)]` to the crate attributes to enable
LL + #![feature(effects)]
|
error: aborting due to 1 previous error
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0015`.
Some errors have detailed explanations: E0015, E0277.
For more information about an error, try `rustc --explain E0015`.

1
tests/ui/traits/const-traits/staged-api-user-crate.rs
View File

@ -11,6 +11,7 @@ fn non_const_context() {
const fn stable_const_context() {
Unstable::func();
//~^ ERROR cannot call non-const fn `<staged_api::Unstable as staged_api::MyTrait>::func` in constant functions
//~| ERROR cannot call non-const fn `<staged_api::Unstable as staged_api::MyTrait>::func` in constant functions
}
fn main() {}

15
tests/ui/traits/const-traits/staged-api-user-crate.stderr
View File

@ -10,6 +10,19 @@ help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
LL + #![feature(const_trait_impl)]
|
error: aborting due to 1 previous error
error[E0015]: cannot call non-const fn `<staged_api::Unstable as staged_api::MyTrait>::func` in constant functions
--> $DIR/staged-api-user-crate.rs:12:5
|
LL | Unstable::func();
| ^^^^^^^^^^^^^^^^
|
= note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
|
LL + #![feature(const_trait_impl)]
|
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0015`.