From 07f903e0e0816821c41a19774f029086b557738b Mon Sep 17 00:00:00 2001 From: Lamb Date: Sat, 3 Jul 2021 12:07:06 +0200 Subject: [PATCH] fn must be const if marked with stability attribut MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit remove trailing newline fix: test with attribute but missing const Update compiler/rustc_passes/src/stability.rs Co-authored-by: Léo Lanteri Thauvin Add test for extern functions fix: using span_help instead of span_suggestion add test for some ABIs + fmt fix Update compiler/rustc_passes/src/stability.rs Co-authored-by: Léo Lanteri Thauvin Refractor and add test for `impl const` Add test to make sure no output + cleanup condition ----------------------------- remove stdcall test, failing CI test C abi is already tested in this, so it is not that useful to test another one. The tested code is blind to which specific ABI for now, as long as it's not an intrinsic one --- .../src/error_codes/E0542.md | 4 +- .../src/error_codes/E0545.md | 4 +- .../src/error_codes/E0547.md | 4 +- compiler/rustc_passes/src/stability.rs | 61 ++++++++++++- .../rustc-const-stability-require-const.rs | 47 ++++++++++ ...rustc-const-stability-require-const.stderr | 86 +++++++++++++++++++ .../ui/consts/rustc-impl-const-stability.rs | 21 +++++ 7 files changed, 220 insertions(+), 7 deletions(-) create mode 100644 src/test/ui/consts/rustc-const-stability-require-const.rs create mode 100644 src/test/ui/consts/rustc-const-stability-require-const.stderr create mode 100644 src/test/ui/consts/rustc-impl-const-stability.rs diff --git a/compiler/rustc_error_codes/src/error_codes/E0542.md b/compiler/rustc_error_codes/src/error_codes/E0542.md index 7cb58f9d0cb..7fecfeaa57c 100644 --- a/compiler/rustc_error_codes/src/error_codes/E0542.md +++ b/compiler/rustc_error_codes/src/error_codes/E0542.md @@ -10,7 +10,7 @@ Erroneous code example: fn _stable_fn() {} #[rustc_const_stable(feature = "_stable_const_fn")] // invalid -fn _stable_const_fn() {} +const fn _stable_const_fn() {} #[stable(feature = "_deprecated_fn", since = "0.1.0")] #[rustc_deprecated( @@ -29,7 +29,7 @@ To fix this issue, you need to provide the `since` field. Example: fn _stable_fn() {} #[rustc_const_stable(feature = "_stable_const_fn", since = "1.0.0")] // ok! -fn _stable_const_fn() {} +const fn _stable_const_fn() {} #[stable(feature = "_deprecated_fn", since = "0.1.0")] #[rustc_deprecated( diff --git a/compiler/rustc_error_codes/src/error_codes/E0545.md b/compiler/rustc_error_codes/src/error_codes/E0545.md index 9fb935a3ab1..7aba084f4d3 100644 --- a/compiler/rustc_error_codes/src/error_codes/E0545.md +++ b/compiler/rustc_error_codes/src/error_codes/E0545.md @@ -10,7 +10,7 @@ Erroneous code example: fn _unstable_fn() {} #[rustc_const_unstable(feature = "_unstable_const_fn", issue = "0")] // invalid -fn _unstable_const_fn() {} +const fn _unstable_const_fn() {} ``` To fix this issue, you need to provide a correct value in the `issue` field. @@ -24,7 +24,7 @@ Example: fn _unstable_fn() {} #[rustc_const_unstable(feature = "_unstable_const_fn", issue = "1")] // ok! -fn _unstable_const_fn() {} +const fn _unstable_const_fn() {} ``` See the [How Rust is Made and “Nightly Rust”][how-rust-made-nightly] appendix diff --git a/compiler/rustc_error_codes/src/error_codes/E0547.md b/compiler/rustc_error_codes/src/error_codes/E0547.md index 1aa4b354248..4950325df64 100644 --- a/compiler/rustc_error_codes/src/error_codes/E0547.md +++ b/compiler/rustc_error_codes/src/error_codes/E0547.md @@ -10,7 +10,7 @@ Erroneous code example: fn _unstable_fn() {} #[rustc_const_unstable(feature = "_unstable_const_fn")] // invalid -fn _unstable_const_fn() {} +const fn _unstable_const_fn() {} ``` To fix this issue, you need to provide the `issue` field. Example: @@ -26,7 +26,7 @@ fn _unstable_fn() {} feature = "_unstable_const_fn", issue = "none" )] // ok! -fn _unstable_const_fn() {} +const fn _unstable_const_fn() {} ``` See the [How Rust is Made and “Nightly Rust”][how-rust-made-nightly] appendix diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs index 5830245e837..cd8dd6984d5 100644 --- a/compiler/rustc_passes/src/stability.rs +++ b/compiler/rustc_passes/src/stability.rs @@ -20,6 +20,7 @@ use rustc_session::Session; use rustc_span::symbol::{sym, Symbol}; use rustc_span::{Span, DUMMY_SP}; +use rustc_target::spec::abi::Abi; use std::cmp::Ordering; use std::iter; @@ -95,10 +96,12 @@ struct Annotator<'a, 'tcx> { impl<'a, 'tcx> Annotator<'a, 'tcx> { // Determine the stability for a node based on its attributes and inherited // stability. The stability is recorded in the index and used as the parent. + // If the node is a function, `fn_sig` is its signature fn annotate( &mut self, hir_id: HirId, item_sp: Span, + fn_sig: Option<&'tcx hir::FnSig<'tcx>>, kind: AnnotationKind, inherit_deprecation: InheritDeprecation, inherit_const_stability: InheritConstStability, @@ -163,13 +166,30 @@ fn annotate( } let (stab, const_stab) = attr::find_stability(&self.tcx.sess, attrs, item_sp); + let mut const_span = None; - let const_stab = const_stab.map(|(const_stab, _)| { + let const_stab = const_stab.map(|(const_stab, const_span_node)| { let const_stab = self.tcx.intern_const_stability(const_stab); self.index.const_stab_map.insert(hir_id, const_stab); + const_span = Some(const_span_node); const_stab }); + // If the current node is a function, has const stability attributes and if it doesn not have an intrinsic ABI, + // check if the function/method is const or the parent impl block is const + if let (Some(const_span), Some(fn_sig)) = (const_span, fn_sig) { + if fn_sig.header.abi != Abi::RustIntrinsic + && fn_sig.header.abi != Abi::PlatformIntrinsic + && !fn_sig.header.is_const() + { + if !self.in_trait_impl + || (self.in_trait_impl && !self.tcx.is_const_fn_raw(hir_id.owner.to_def_id())) + { + missing_const_err(&self.tcx.sess, fn_sig.span, const_span); + } + } + } + // `impl const Trait for Type` items forward their const stability to their // immediate children. if const_stab.is_none() { @@ -367,6 +387,8 @@ fn visit_item(&mut self, i: &'tcx Item<'tcx>) { let orig_in_trait_impl = self.in_trait_impl; let mut kind = AnnotationKind::Required; let mut const_stab_inherit = InheritConstStability::No; + let mut fn_sig = None; + match i.kind { // Inherent impls and foreign modules serve only as containers for other items, // they don't have their own stability. They still can be annotated as unstable @@ -387,6 +409,7 @@ fn visit_item(&mut self, i: &'tcx Item<'tcx>) { self.annotate( ctor_hir_id, i.span, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -395,12 +418,16 @@ fn visit_item(&mut self, i: &'tcx Item<'tcx>) { ) } } + hir::ItemKind::Fn(ref item_fn_sig, _, _) => { + fn_sig = Some(item_fn_sig); + } _ => {} } self.annotate( i.hir_id(), i.span, + fn_sig, kind, InheritDeprecation::Yes, const_stab_inherit, @@ -411,9 +438,15 @@ fn visit_item(&mut self, i: &'tcx Item<'tcx>) { } fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem<'tcx>) { + let fn_sig = match ti.kind { + hir::TraitItemKind::Fn(ref fn_sig, _) => Some(fn_sig), + _ => None, + }; + self.annotate( ti.hir_id(), ti.span, + fn_sig, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -427,9 +460,16 @@ fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem<'tcx>) { fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem<'tcx>) { let kind = if self.in_trait_impl { AnnotationKind::Prohibited } else { AnnotationKind::Required }; + + let fn_sig = match ii.kind { + hir::ImplItemKind::Fn(ref fn_sig, _) => Some(fn_sig), + _ => None, + }; + self.annotate( ii.hir_id(), ii.span, + fn_sig, kind, InheritDeprecation::Yes, InheritConstStability::No, @@ -444,6 +484,7 @@ fn visit_variant(&mut self, var: &'tcx Variant<'tcx>, g: &'tcx Generics<'tcx>, i self.annotate( var.id, var.span, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -453,6 +494,7 @@ fn visit_variant(&mut self, var: &'tcx Variant<'tcx>, g: &'tcx Generics<'tcx>, i v.annotate( ctor_hir_id, var.span, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -470,6 +512,7 @@ fn visit_field_def(&mut self, s: &'tcx FieldDef<'tcx>) { self.annotate( s.hir_id, s.span, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -484,6 +527,7 @@ fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem<'tcx>) { self.annotate( i.hir_id(), i.span, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -498,6 +542,7 @@ fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef<'tcx>) { self.annotate( md.hir_id(), md.span, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -517,6 +562,7 @@ fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam<'tcx>) { self.annotate( p.hir_id, p.span, + None, kind, InheritDeprecation::No, InheritConstStability::No, @@ -687,6 +733,7 @@ fn stability_index(tcx: TyCtxt<'tcx>, (): ()) -> Index<'tcx> { annotator.annotate( hir::CRATE_HIR_ID, krate.item.inner, + None, AnnotationKind::Required, InheritDeprecation::Yes, InheritConstStability::No, @@ -969,3 +1016,15 @@ fn duplicate_feature_err(sess: &Session, span: Span, feature: Symbol) { struct_span_err!(sess, span, E0636, "the feature `{}` has already been declared", feature) .emit(); } + +fn missing_const_err(session: &Session, fn_sig_span: Span, const_span: Span) { + const ERROR_MSG: &'static str = "attributes `#[rustc_const_unstable]` \ + and `#[rustc_const_stable]` require \ + the function or method to be `const`"; + + session + .struct_span_err(fn_sig_span, ERROR_MSG) + .span_help(fn_sig_span, "make the function or method const") + .span_label(const_span, "attribute specified here") + .emit(); +} diff --git a/src/test/ui/consts/rustc-const-stability-require-const.rs b/src/test/ui/consts/rustc-const-stability-require-const.rs new file mode 100644 index 00000000000..4fb259b335c --- /dev/null +++ b/src/test/ui/consts/rustc-const-stability-require-const.rs @@ -0,0 +1,47 @@ +#![crate_type = "lib"] +#![feature(staged_api)] +#![stable(feature = "foo", since = "1.0.0")] + +#[stable(feature = "foo", since = "1.0.0")] +#[rustc_const_unstable(feature = "const_foo", issue = "none")] +pub fn foo() {} +//~^ ERROR attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + +#[stable(feature = "bar", since = "1.0.0")] +#[rustc_const_stable(feature = "const_bar", since = "1.0.0")] +pub fn bar() {} +//~^ ERROR attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + +#[stable(feature = "potato", since = "1.0.0")] +pub struct Potato; + +impl Potato { + #[stable(feature = "salad", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_salad", issue = "none")] + pub fn salad(&self) -> &'static str { "mmmmmm" } + //~^ ERROR attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + + #[stable(feature = "roasted", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_roasted", issue = "none")] + pub fn roasted(&self) -> &'static str { "mmmmmmmmmm" } + //~^ ERROR attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` +} + +#[stable(feature = "bar", since = "1.0.0")] +#[rustc_const_stable(feature = "const_bar", since = "1.0.0")] +pub extern "C" fn bar_c() {} +//~^ ERROR attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + +#[stable(feature = "foo", since = "1.0.0")] +#[rustc_const_unstable(feature = "const_foo", issue = "none")] +pub extern "C" fn foo_c() {} +//~^ ERROR attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + + +#[stable(feature = "foobar", since = "1.0.0")] +#[rustc_const_unstable(feature = "foobar_const", issue = "none")] +pub const fn foobar() {} + +#[stable(feature = "barfoo", since = "1.0.0")] +#[rustc_const_stable(feature = "barfoo_const", since = "1.0.0")] +pub const fn barfoo() {} diff --git a/src/test/ui/consts/rustc-const-stability-require-const.stderr b/src/test/ui/consts/rustc-const-stability-require-const.stderr new file mode 100644 index 00000000000..1027b9311b7 --- /dev/null +++ b/src/test/ui/consts/rustc-const-stability-require-const.stderr @@ -0,0 +1,86 @@ +error: attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + --> $DIR/rustc-const-stability-require-const.rs:7:1 + | +LL | #[rustc_const_unstable(feature = "const_foo", issue = "none")] + | -------------------------------------------------------------- attribute specified here +LL | pub fn foo() {} + | ^^^^^^^^^^^^ + | +help: make the function or method const + --> $DIR/rustc-const-stability-require-const.rs:7:1 + | +LL | pub fn foo() {} + | ^^^^^^^^^^^^ + +error: attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + --> $DIR/rustc-const-stability-require-const.rs:12:1 + | +LL | #[rustc_const_stable(feature = "const_bar", since = "1.0.0")] + | ------------------------------------------------------------- attribute specified here +LL | pub fn bar() {} + | ^^^^^^^^^^^^ + | +help: make the function or method const + --> $DIR/rustc-const-stability-require-const.rs:12:1 + | +LL | pub fn bar() {} + | ^^^^^^^^^^^^ + +error: attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + --> $DIR/rustc-const-stability-require-const.rs:21:5 + | +LL | #[rustc_const_unstable(feature = "const_salad", issue = "none")] + | ---------------------------------------------------------------- attribute specified here +LL | pub fn salad(&self) -> &'static str { "mmmmmm" } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: make the function or method const + --> $DIR/rustc-const-stability-require-const.rs:21:5 + | +LL | pub fn salad(&self) -> &'static str { "mmmmmm" } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + --> $DIR/rustc-const-stability-require-const.rs:26:5 + | +LL | #[rustc_const_unstable(feature = "const_roasted", issue = "none")] + | ------------------------------------------------------------------ attribute specified here +LL | pub fn roasted(&self) -> &'static str { "mmmmmmmmmm" } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: make the function or method const + --> $DIR/rustc-const-stability-require-const.rs:26:5 + | +LL | pub fn roasted(&self) -> &'static str { "mmmmmmmmmm" } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + --> $DIR/rustc-const-stability-require-const.rs:32:1 + | +LL | #[rustc_const_stable(feature = "const_bar", since = "1.0.0")] + | ------------------------------------------------------------- attribute specified here +LL | pub extern "C" fn bar_c() {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: make the function or method const + --> $DIR/rustc-const-stability-require-const.rs:32:1 + | +LL | pub extern "C" fn bar_c() {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: attributes `#[rustc_const_unstable]` and `#[rustc_const_stable]` require the function or method to be `const` + --> $DIR/rustc-const-stability-require-const.rs:37:1 + | +LL | #[rustc_const_unstable(feature = "const_foo", issue = "none")] + | -------------------------------------------------------------- attribute specified here +LL | pub extern "C" fn foo_c() {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: make the function or method const + --> $DIR/rustc-const-stability-require-const.rs:37:1 + | +LL | pub extern "C" fn foo_c() {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 6 previous errors + diff --git a/src/test/ui/consts/rustc-impl-const-stability.rs b/src/test/ui/consts/rustc-impl-const-stability.rs new file mode 100644 index 00000000000..01daa1c9cb4 --- /dev/null +++ b/src/test/ui/consts/rustc-impl-const-stability.rs @@ -0,0 +1,21 @@ +// build-pass + +#![crate_type = "lib"] +#![allow(incomplete_features)] +#![feature(staged_api)] +#![feature(const_trait_impl)] +#![stable(feature = "foo", since = "1.0.0")] + + +#[stable(feature = "potato", since = "1.27.0")] +pub struct Data { + _data: u128 +} + +#[stable(feature = "potato", since = "1.27.0")] +impl const Default for Data { + #[rustc_const_unstable(feature = "data_foo", issue = "none")] + fn default() -> Data { + Data { _data: 42 } + } +} -- 2.44.0