diff options
Diffstat (limited to 'compiler/rustc_const_eval/src')
4 files changed, 36 insertions, 13 deletions
diff --git a/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs b/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs index ba2e2a1e353..de8de021b09 100644 --- a/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/dummy_machine.rs @@ -47,6 +47,12 @@ impl<'mir, 'tcx: 'mir> interpret::Machine<'mir, 'tcx> for DummyMachine { const PANIC_ON_ALLOC_FAIL: bool = true; #[inline(always)] + fn all_required_consts_are_checked(_ecx: &InterpCx<'mir, 'tcx, Self>) -> bool { + // We want to just eval random consts in the program, so `eval_mir_const` can fail. + false + } + + #[inline(always)] fn enforce_alignment(_ecx: &InterpCx<'mir, 'tcx, Self>) -> bool { false // no reason to enforce alignment } diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs index dd835279df3..2d06460f353 100644 --- a/compiler/rustc_const_eval/src/const_eval/machine.rs +++ b/compiler/rustc_const_eval/src/const_eval/machine.rs @@ -375,6 +375,20 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, const PANIC_ON_ALLOC_FAIL: bool = false; // will be raised as a proper error + #[inline] + fn all_required_consts_are_checked(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool { + // Generally we expect required_consts to be properly filled, except for promoteds where + // storing these consts shows up negatively in benchmarks. A promoted can only be relevant + // if its parent MIR is relevant, and the consts in the promoted will be in the parent's + // `required_consts`, so we are still sure to catch any const-eval bugs, just a bit less + // directly. + if ecx.frame_idx() == 0 && ecx.frame().body.source.promoted.is_some() { + false + } else { + true + } + } + #[inline(always)] fn enforce_alignment(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool { matches!(ecx.machine.check_alignment, CheckAlignment::Error) diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs index 62d169db628..8f7c2580ad4 100644 --- a/compiler/rustc_const_eval/src/interpret/eval_context.rs +++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs @@ -822,15 +822,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { self.stack_mut().push(frame); // Make sure all the constants required by this frame evaluate successfully (post-monomorphization check). - if M::POST_MONO_CHECKS { - for &const_ in &body.required_consts { - let c = self - .instantiate_from_current_frame_and_normalize_erasing_regions(const_.const_)?; - c.eval(*self.tcx, self.param_env, const_.span).map_err(|err| { - err.emit_note(*self.tcx); - err - })?; - } + for &const_ in &body.required_consts { + let c = + self.instantiate_from_current_frame_and_normalize_erasing_regions(const_.const_)?; + c.eval(*self.tcx, self.param_env, const_.span).map_err(|err| { + err.emit_note(*self.tcx); + err + })?; } // done @@ -1181,8 +1179,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> { M::eval_mir_constant(self, *val, span, layout, |ecx, val, span, layout| { let const_val = val.eval(*ecx.tcx, ecx.param_env, span).map_err(|err| { - // FIXME: somehow this is reachable even when POST_MONO_CHECKS is on. - // Are we not always populating `required_consts`? + if M::all_required_consts_are_checked(self) + && !matches!(err, ErrorHandled::TooGeneric(..)) + { + // Looks like the const is not captued by `required_consts`, that's bad. + bug!("interpret const eval failure of {val:?} which is not in required_consts"); + } err.emit_note(*ecx.tcx); err })?; diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs index 7617cb57b3c..e8ecbe089c3 100644 --- a/compiler/rustc_const_eval/src/interpret/machine.rs +++ b/compiler/rustc_const_eval/src/interpret/machine.rs @@ -140,8 +140,9 @@ pub trait Machine<'mir, 'tcx: 'mir>: Sized { /// Should the machine panic on allocation failures? const PANIC_ON_ALLOC_FAIL: bool; - /// Should post-monomorphization checks be run when a stack frame is pushed? - const POST_MONO_CHECKS: bool = true; + /// Determines whether `eval_mir_constant` can never fail because all required consts have + /// already been checked before. + fn all_required_consts_are_checked(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool; /// Whether memory accesses should be alignment-checked. fn enforce_alignment(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool; |