From d3e0d2f53dd69bf10b4260760e5fbaddc77c2a3d Mon Sep 17 00:00:00 2001 From: lcnr Date: Sun, 18 Apr 2021 16:43:43 +0200 Subject: [PATCH] supply substs to anon consts in defaults --- compiler/rustc_typeck/src/astconv/mod.rs | 4 +- .../rustc_typeck/src/check/fn_ctxt/_impl.rs | 4 +- compiler/rustc_typeck/src/collect.rs | 39 +++++++++---------- .../complex-generic-default-expr.full.stderr | 24 ++++++------ .../complex-generic-default-expr.min.stderr | 4 +- .../defaults/complex-generic-default-expr.rs | 13 +++---- .../defaults/const-param-as-default-value.rs | 9 +++++ .../defaults/const-param-in-ty-defaults.rs | 4 -- ...ms-in-ct-in-ty-param-lazy-norm.full.stderr | 22 ++--------- ...ams-in-ct-in-ty-param-lazy-norm.min.stderr | 6 +-- .../params-in-ct-in-ty-param-lazy-norm.rs | 4 +- 11 files changed, 62 insertions(+), 71 deletions(-) diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs index b6de491911ab7..62a1584d16be0 100644 --- a/compiler/rustc_typeck/src/astconv/mod.rs +++ b/compiler/rustc_typeck/src/astconv/mod.rs @@ -513,7 +513,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { GenericParamDefKind::Const { has_default } => { let ty = tcx.at(self.span).type_of(param.def_id); if !infer_args && has_default { - tcx.const_param_default(param.def_id).into() + tcx.const_param_default(param.def_id) + .subst_spanned(tcx, substs.unwrap(), Some(self.span)) + .into() } else { if infer_args { self.astconv.ct_infer(ty, Some(param), self.span).into() diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs index 9ace455042103..a50f8e1c65599 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs @@ -1446,7 +1446,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } GenericParamDefKind::Const { has_default, .. } => { if !infer_args && has_default { - tcx.const_param_default(param.def_id).into() + tcx.const_param_default(param.def_id) + .subst_spanned(tcx, substs.unwrap(), Some(self.span)) + .into() } else { self.fcx.var_for_def(self.span, param) } diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index 1477418d5d8cf..927d8c57191a7 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -1316,13 +1316,13 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option Visitor<'v> for AnonConstInParamListDetector { +impl<'v> Visitor<'v> for AnonConstInParamTyDetector { type Map = intravisit::ErasedMap<'v>; fn nested_visit_map(&mut self) -> NestedVisitorMap { @@ -1330,15 +1330,17 @@ impl<'v> Visitor<'v> for AnonConstInParamListDetector { } fn visit_generic_param(&mut self, p: &'v hir::GenericParam<'v>) { - let prev = self.in_param_list; - self.in_param_list = true; - intravisit::walk_generic_param(self, p); - self.in_param_list = prev; + if let GenericParamKind::Const { ref ty, default: _ } = p.kind { + let prev = self.in_param_ty; + self.in_param_ty = true; + self.visit_ty(ty); + self.in_param_ty = prev; + } } fn visit_anon_const(&mut self, c: &'v hir::AnonConst) { - if self.in_param_list && self.ct == c.hir_id { - self.found_anon_const_in_list = true; + if self.in_param_ty && self.ct == c.hir_id { + self.found_anon_const_in_param_ty = true; } else { intravisit::walk_anon_const(self, c) } @@ -1366,27 +1368,24 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics { let parent_id = tcx.hir().get_parent_item(hir_id); let parent_def_id = tcx.hir().local_def_id(parent_id); - let mut in_param_list = false; + let mut in_param_ty = false; for (_parent, node) in tcx.hir().parent_iter(hir_id) { if let Some(generics) = node.generics() { - let mut visitor = AnonConstInParamListDetector { - in_param_list: false, - found_anon_const_in_list: false, + let mut visitor = AnonConstInParamTyDetector { + in_param_ty: false, + found_anon_const_in_param_ty: false, ct: hir_id, }; visitor.visit_generics(generics); - in_param_list = visitor.found_anon_const_in_list; + in_param_ty = visitor.found_anon_const_in_param_ty; break; } } - if in_param_list { + if in_param_ty { // We do not allow generic parameters in anon consts if we are inside - // of a param list. - // - // This affects both default type bindings, e.g. `struct()]>(T, U)`, - // and the types of const parameters, e.g. `struct V();`. + // of a const parameter type, e.g. `struct Foo` is not allowed. None } else if tcx.lazy_normalization() { // HACK(eddyb) this provides the correct generics when diff --git a/src/test/ui/const-generics/defaults/complex-generic-default-expr.full.stderr b/src/test/ui/const-generics/defaults/complex-generic-default-expr.full.stderr index c1444abbd3f32..e0e2b6c69f280 100644 --- a/src/test/ui/const-generics/defaults/complex-generic-default-expr.full.stderr +++ b/src/test/ui/const-generics/defaults/complex-generic-default-expr.full.stderr @@ -1,16 +1,18 @@ -error[E0277]: the size for values of type `T` cannot be known at compilation time - --> $DIR/complex-generic-default-expr.rs:9:62 +error: constant expression depends on a generic parameter + --> $DIR/complex-generic-default-expr.rs:6:34 + | +LL | struct Foo; + | ^ + | + = note: this may fail depending on what value the parameter takes + +error: constant expression depends on a generic parameter + --> $DIR/complex-generic-default-expr.rs:10:21 | LL | struct Bar() }>(T); - | - ^ doesn't have a size known at compile-time - | | - | this type parameter needs to be `std::marker::Sized` - | - ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL + | ^^^^^^^^^ | -LL | pub const fn size_of() -> usize { - | - required by this bound in `std::mem::size_of` + = note: this may fail depending on what value the parameter takes -error: aborting due to previous error +error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/const-generics/defaults/complex-generic-default-expr.min.stderr b/src/test/ui/const-generics/defaults/complex-generic-default-expr.min.stderr index 7d51e9aa0f3be..58abd8db9f09f 100644 --- a/src/test/ui/const-generics/defaults/complex-generic-default-expr.min.stderr +++ b/src/test/ui/const-generics/defaults/complex-generic-default-expr.min.stderr @@ -1,5 +1,5 @@ error: generic parameters may not be used in const operations - --> $DIR/complex-generic-default-expr.rs:10:47 + --> $DIR/complex-generic-default-expr.rs:6:47 | LL | struct Foo; | ^ cannot perform const operation using `N` @@ -8,7 +8,7 @@ LL | struct Foo; = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions error: generic parameters may not be used in const operations - --> $DIR/complex-generic-default-expr.rs:13:62 + --> $DIR/complex-generic-default-expr.rs:10:62 | LL | struct Bar() }>(T); | ^ cannot perform const operation using `T` diff --git a/src/test/ui/const-generics/defaults/complex-generic-default-expr.rs b/src/test/ui/const-generics/defaults/complex-generic-default-expr.rs index a1c04b5e7c387..a7b712f7b4b86 100644 --- a/src/test/ui/const-generics/defaults/complex-generic-default-expr.rs +++ b/src/test/ui/const-generics/defaults/complex-generic-default-expr.rs @@ -1,17 +1,14 @@ -// revisions: min -// FIXME(const_generics): add the `full` revision, -// currently causes an ICE as we don't supply substs to -// anon consts in the parameter listing, as that would -// cause that anon const to reference itself. +// revisions: full min #![cfg_attr(full, feature(const_generics))] #![feature(const_generics_defaults)] #![allow(incomplete_features)] struct Foo; -//[min]~^ ERROR generic parameters may not be used in const operations +//[full]~^ ERROR constant expression depends on a generic parameter +//[min]~^^ ERROR generic parameters may not be used in const operations struct Bar() }>(T); -//[min]~^ ERROR generic parameters may not be used in const operations -//[full]~^^ ERROR the size for values of type `T` cannot be known at compilation time +//[full]~^ ERROR constant expression depends on a generic parameter +//[min]~^^ ERROR generic parameters may not be used in const operations fn main() {} diff --git a/src/test/ui/const-generics/defaults/const-param-as-default-value.rs b/src/test/ui/const-generics/defaults/const-param-as-default-value.rs index d9cab34327e9d..59ac261f44fd5 100644 --- a/src/test/ui/const-generics/defaults/const-param-as-default-value.rs +++ b/src/test/ui/const-generics/defaults/const-param-as-default-value.rs @@ -8,7 +8,16 @@ fn foo() -> Foo { Foo(x, x) } +// To check that we actually apply the correct substs for const param defaults. +fn concrete_foo() -> Foo<13> { + Foo(Default::default(), Default::default()) +} + + fn main() { let val = foo::<13>(); assert_eq!(val.0, val.1); + + let val = concrete_foo(); + assert_eq!(val.0, val.1); } diff --git a/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs b/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs index e3d78fe2ee0ea..3f534ca0308ba 100644 --- a/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs +++ b/src/test/ui/const-generics/defaults/const-param-in-ty-defaults.rs @@ -1,10 +1,6 @@ // run-pass #![feature(const_generics_defaults)] #![allow(incomplete_features)] -// FIXME(const_generics_defaults): while we can allow this, -// we probably won't easily allow this with more complex const operations. -// -// So we have to make a conscious decision here when stabilizing a relaxed parameter ordering. struct Foo(T); impl Foo { diff --git a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.full.stderr b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.full.stderr index cf947a565c454..e8fd9e7769b79 100644 --- a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.full.stderr +++ b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.full.stderr @@ -1,5 +1,5 @@ error: generic parameters with a default must be trailing - --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:10:12 + --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:8:12 | LL | struct Bar(T); | ^ @@ -7,25 +7,11 @@ LL | struct Bar(T); = note: using type defaults and const parameters in the same parameter list is currently not permitted error[E0128]: generic parameters with a default cannot use forward declared identifiers - --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:10:21 + --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:8:21 | LL | struct Bar(T); | ^ defaulted generic parameters cannot be forward declared -error[E0277]: the size for values of type `T` cannot be known at compilation time - --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:6:44 - | -LL | struct Foo()]>(T, U); - | - ^ doesn't have a size known at compile-time - | | - | this type parameter needs to be `std::marker::Sized` - | - ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL - | -LL | pub const fn size_of() -> usize { - | - required by this bound in `std::mem::size_of` - -error: aborting due to 3 previous errors +error: aborting due to 2 previous errors -Some errors have detailed explanations: E0128, E0277. -For more information about an error, try `rustc --explain E0128`. +For more information about this error, try `rustc --explain E0128`. diff --git a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr index 4c97012f36185..5fa6423306c5a 100644 --- a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr +++ b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr @@ -1,5 +1,5 @@ error: generic parameters with a default must be trailing - --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:10:12 + --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:8:12 | LL | struct Bar(T); | ^ @@ -7,7 +7,7 @@ LL | struct Bar(T); = note: using type defaults and const parameters in the same parameter list is currently not permitted error: generic parameters may not be used in const operations - --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:6:44 + --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:5:44 | LL | struct Foo()]>(T, U); | ^ cannot perform const operation using `T` @@ -16,7 +16,7 @@ LL | struct Foo()]>(T, U); = help: use `#![feature(const_generics)]` and `#![feature(const_evaluatable_checked)]` to allow generic const expressions error[E0128]: generic parameters with a default cannot use forward declared identifiers - --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:10:21 + --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:8:21 | LL | struct Bar(T); | ^ defaulted generic parameters cannot be forward declared diff --git a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.rs b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.rs index bf4f9558adc26..76c1b84aef557 100644 --- a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.rs +++ b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.rs @@ -1,11 +1,9 @@ // revisions: full min - #![cfg_attr(full, feature(const_generics))] #![cfg_attr(full, allow(incomplete_features))] struct Foo()]>(T, U); -//[full]~^ ERROR the size for values of type `T` cannot be known at compilation time -//[min]~^^ ERROR generic parameters may not be used in const operations +//[min]~^ ERROR generic parameters may not be used in const operations struct Bar(T); //~^ ERROR generic parameters with a default cannot use forward declared identifiers