From b334eef162ba9c10faa97c9d5c5d249f25afc7df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Tue, 13 Oct 2020 21:42:59 -0700 Subject: [PATCH 1/2] Do not ICE with TraitPredicates containing [type error] Fix #77919. --- .../src/traits/select/mod.rs | 19 +++++--- src/test/ui/issues/issue-77919.rs | 13 ++++++ src/test/ui/issues/issue-77919.stderr | 46 +++++++++++++++++++ 3 files changed, 72 insertions(+), 6 deletions(-) create mode 100644 src/test/ui/issues/issue-77919.rs create mode 100644 src/test/ui/issues/issue-77919.stderr diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 4cc4bc0acdab6..d4124c82197cb 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -2031,12 +2031,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { &predicate.subst(tcx, substs), &mut obligations, ); - obligations.push(Obligation { - cause: cause.clone(), - recursion_depth, - param_env, - predicate, - }); + if predicate.references_error() { + self.tcx().sess.delay_span_bug( + cause.span, + &format!("impl_or_trait_obligation with errors: {:?}", predicate), + ); + } else { + obligations.push(Obligation { + cause: cause.clone(), + recursion_depth, + param_env, + predicate, + }); + } } // We are performing deduplication here to avoid exponential blowups diff --git a/src/test/ui/issues/issue-77919.rs b/src/test/ui/issues/issue-77919.rs new file mode 100644 index 0000000000000..9b04d5ee0008d --- /dev/null +++ b/src/test/ui/issues/issue-77919.rs @@ -0,0 +1,13 @@ +fn main() { + [1; >::VAL]; //~ ERROR evaluation of constant value failed +} +trait TypeVal { + const VAL: T; //~ ERROR any use of this value will cause an error +} +struct Five; +struct Multiply { + _n: PhantomData, //~ ERROR cannot find type `PhantomData` in this scope +} +impl TypeVal for Multiply where N: TypeVal {} +//~^ ERROR cannot find type `VAL` in this scope +//~| ERROR not all trait items implemented, missing: `VAL` diff --git a/src/test/ui/issues/issue-77919.stderr b/src/test/ui/issues/issue-77919.stderr new file mode 100644 index 0000000000000..129af00644fff --- /dev/null +++ b/src/test/ui/issues/issue-77919.stderr @@ -0,0 +1,46 @@ +error[E0412]: cannot find type `PhantomData` in this scope + --> $DIR/issue-77919.rs:9:9 + | +LL | _n: PhantomData, + | ^^^^^^^^^^^ not found in this scope + | +help: consider importing this struct + | +LL | use std::marker::PhantomData; + | + +error[E0412]: cannot find type `VAL` in this scope + --> $DIR/issue-77919.rs:11:63 + | +LL | impl TypeVal for Multiply where N: TypeVal {} + | - ^^^ not found in this scope + | | + | help: you might be missing a type parameter: `, VAL` + +error[E0046]: not all trait items implemented, missing: `VAL` + --> $DIR/issue-77919.rs:11:1 + | +LL | const VAL: T; + | ------------- `VAL` from trait +... +LL | impl TypeVal for Multiply where N: TypeVal {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `VAL` in implementation + +error: any use of this value will cause an error + --> $DIR/issue-77919.rs:5:5 + | +LL | const VAL: T; + | ^^^^^^^^^^^^^ no MIR body is available for DefId(0:7 ~ issue_77919[317d]::TypeVal::VAL) + | + = note: `#[deny(const_err)]` on by default + +error[E0080]: evaluation of constant value failed + --> $DIR/issue-77919.rs:2:9 + | +LL | [1; >::VAL]; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ referenced constant has errors + +error: aborting due to 5 previous errors + +Some errors have detailed explanations: E0046, E0080, E0412. +For more information about an error, try `rustc --explain E0046`. From f71e9ed7f1b88f303519dcd7c2cc69117ff95094 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Fri, 23 Oct 2020 12:51:06 -0700 Subject: [PATCH 2/2] review comments --- .../src/traits/codegen.rs | 5 ++++- .../src/traits/select/mod.rs | 19 ++++++------------- 2 files changed, 10 insertions(+), 14 deletions(-) diff --git a/compiler/rustc_trait_selection/src/traits/codegen.rs b/compiler/rustc_trait_selection/src/traits/codegen.rs index 05e6c4804ff65..3cb6ec8626186 100644 --- a/compiler/rustc_trait_selection/src/traits/codegen.rs +++ b/compiler/rustc_trait_selection/src/traits/codegen.rs @@ -121,7 +121,10 @@ where // contains unbound type parameters. It could be a slight // optimization to stop iterating early. if let Err(errors) = fulfill_cx.select_all_or_error(infcx) { - bug!("Encountered errors `{:?}` resolving bounds after type-checking", errors); + infcx.tcx.sess.delay_span_bug( + rustc_span::DUMMY_SP, + &format!("Encountered errors `{:?}` resolving bounds after type-checking", errors), + ); } let result = infcx.resolve_vars_if_possible(result); diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index d4124c82197cb..4cc4bc0acdab6 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -2031,19 +2031,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { &predicate.subst(tcx, substs), &mut obligations, ); - if predicate.references_error() { - self.tcx().sess.delay_span_bug( - cause.span, - &format!("impl_or_trait_obligation with errors: {:?}", predicate), - ); - } else { - obligations.push(Obligation { - cause: cause.clone(), - recursion_depth, - param_env, - predicate, - }); - } + obligations.push(Obligation { + cause: cause.clone(), + recursion_depth, + param_env, + predicate, + }); } // We are performing deduplication here to avoid exponential blowups