diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 6cdf50970836a..fe92d2810a1f1 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -2023,6 +2023,73 @@ declare_lint! { }; } +declare_lint! { + /// The `proc_macro_derive_resolution_fallback` lint detects proc macro + /// derives using inaccessible names from parent modules. + /// + /// ### Example + /// + /// ```rust,ignore (proc-macro) + /// // foo.rs + /// #![crate_type = "proc-macro"] + /// + /// extern crate proc_macro; + /// + /// use proc_macro::*; + /// + /// #[proc_macro_derive(Foo)] + /// pub fn foo1(a: TokenStream) -> TokenStream { + /// drop(a); + /// "mod __bar { static mut BAR: Option = None; }".parse().unwrap() + /// } + /// ``` + /// + /// ```rust,ignore (needs-dependency) + /// // bar.rs + /// #[macro_use] + /// extern crate foo; + /// + /// struct Something; + /// + /// #[derive(Foo)] + /// struct Another; + /// + /// fn main() {} + /// ``` + /// + /// This will produce: + /// + /// ```text + /// warning: cannot find type `Something` in this scope + /// --> src/main.rs:8:10 + /// | + /// 8 | #[derive(Foo)] + /// | ^^^ names from parent modules are not accessible without an explicit import + /// | + /// = note: `#[warn(proc_macro_derive_resolution_fallback)]` on by default + /// = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + /// = note: for more information, see issue #50504 + /// ``` + /// + /// ### Explanation + /// + /// If a proc-macro generates a module, the compiler unintentionally + /// allowed items in that module to refer to items in the crate root + /// without importing them. This is a [future-incompatible] lint to + /// transition this to a hard error in the future. See [issue #50504] for + /// more details. + /// + /// [issue #50504]: https://github.com/rust-lang/rust/issues/50504 + /// [future-incompatible]: ../index.md#future-incompatible-lints + pub PROC_MACRO_DERIVE_RESOLUTION_FALLBACK, + Deny, + "detects proc macro derives using inaccessible names from parent modules", + @future_incompatible = FutureIncompatibleInfo { + reference: "issue #83583 ", + reason: FutureIncompatibilityReason::FutureReleaseErrorReportNow, + }; +} + declare_lint! { /// The `macro_use_extern_crate` lint detects the use of the /// [`macro_use` attribute]. @@ -3261,6 +3328,7 @@ declare_lint_pass! { UNSTABLE_NAME_COLLISIONS, IRREFUTABLE_LET_PATTERNS, WHERE_CLAUSES_OBJECT_SAFETY, + PROC_MACRO_DERIVE_RESOLUTION_FALLBACK, MACRO_USE_EXTERN_CRATE, MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS, ILL_FORMED_ATTRIBUTE_INPUT, diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs index f24e405018b74..e264601c8f94e 100644 --- a/compiler/rustc_resolve/src/diagnostics.rs +++ b/compiler/rustc_resolve/src/diagnostics.rs @@ -1033,7 +1033,7 @@ impl<'a> Resolver<'a> { let root_module = this.resolve_crate_root(root_ident); this.add_module_candidates(root_module, &mut suggestions, filter_fn, None); } - Scope::Module(module) => { + Scope::Module(module, _) => { this.add_module_candidates(module, &mut suggestions, filter_fn, None); } Scope::MacroUsePrelude => { diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs index e41fe325b811c..a84652a315dc2 100644 --- a/compiler/rustc_resolve/src/ident.rs +++ b/compiler/rustc_resolve/src/ident.rs @@ -1,9 +1,11 @@ -use rustc_ast as ast; +use rustc_ast::{self as ast, NodeId}; use rustc_feature::is_builtin_attr_name; use rustc_hir::def::{DefKind, Namespace, NonMacroAttrKind, PartialRes, PerNS}; use rustc_hir::PrimTy; use rustc_middle::bug; use rustc_middle::ty; +use rustc_session::lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK; +use rustc_session::lint::BuiltinLintDiagnostics; use rustc_span::def_id::LocalDefId; use rustc_span::edition::Edition; use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext}; @@ -99,7 +101,7 @@ impl<'a> Resolver<'a> { }; let mut scope = match ns { _ if is_absolute_path => Scope::CrateRoot, - TypeNS | ValueNS => Scope::Module(module), + TypeNS | ValueNS => Scope::Module(module, None), MacroNS => Scope::DeriveHelpers(parent_scope.expansion), }; let mut ctxt = ctxt.normalize_to_macros_2_0(); @@ -163,7 +165,7 @@ impl<'a> Resolver<'a> { MacroRulesScope::Invocation(invoc_id) => { Scope::MacroRules(self.invocation_parent_scopes[&invoc_id].macro_rules) } - MacroRulesScope::Empty => Scope::Module(module), + MacroRulesScope::Empty => Scope::Module(module, None), }, Scope::CrateRoot => match ns { TypeNS => { @@ -172,10 +174,16 @@ impl<'a> Resolver<'a> { } ValueNS | MacroNS => break, }, - Scope::Module(module) => { + Scope::Module(module, prev_lint_id) => { use_prelude = !module.no_implicit_prelude; - match self.hygienic_lexical_parent(module, &mut ctxt) { - Some(parent_module) => Scope::Module(parent_module), + let derive_fallback_lint_id = match scope_set { + ScopeSet::Late(.., lint_id) => lint_id, + _ => None, + }; + match self.hygienic_lexical_parent(module, &mut ctxt, derive_fallback_lint_id) { + Some((parent_module, lint_id)) => { + Scope::Module(parent_module, lint_id.or(prev_lint_id)) + } None => { ctxt.adjust(ExpnId::root()); match ns { @@ -207,13 +215,45 @@ impl<'a> Resolver<'a> { &mut self, module: Module<'a>, ctxt: &mut SyntaxContext, - ) -> Option> { + derive_fallback_lint_id: Option, + ) -> Option<(Module<'a>, Option)> { if !module.expansion.outer_expn_is_descendant_of(*ctxt) { - return Some(self.expn_def_scope(ctxt.remove_mark())); + return Some((self.expn_def_scope(ctxt.remove_mark()), None)); } if let ModuleKind::Block = module.kind { - return Some(module.parent.unwrap().nearest_item_scope()); + return Some((module.parent.unwrap().nearest_item_scope(), None)); + } + + // We need to support the next case under a deprecation warning + // ``` + // struct MyStruct; + // ---- begin: this comes from a proc macro derive + // mod implementation_details { + // // Note that `MyStruct` is not in scope here. + // impl SomeTrait for MyStruct { ... } + // } + // ---- end + // ``` + // So we have to fall back to the module's parent during lexical resolution in this case. + if derive_fallback_lint_id.is_some() { + if let Some(parent) = module.parent { + // Inner module is inside the macro, parent module is outside of the macro. + if module.expansion != parent.expansion + && module.expansion.is_descendant_of(parent.expansion) + { + // The macro is a proc macro derive + if let Some(def_id) = module.expansion.expn_data().macro_def_id { + let ext = self.get_macro_by_def_id(def_id).ext; + if ext.builtin_name.is_none() + && ext.macro_kind() == MacroKind::Derive + && parent.expansion.outer_expn_is_descendant_of(*ctxt) + { + return Some((parent, derive_fallback_lint_id)); + } + } + } + } } None @@ -470,7 +510,7 @@ impl<'a> Resolver<'a> { Err((Determinacy::Determined, _)) => Err(Determinacy::Determined), } } - Scope::Module(module) => { + Scope::Module(module, derive_fallback_lint_id) => { let adjusted_parent_scope = &ParentScope { module, ..*parent_scope }; let binding = this.resolve_ident_in_module_unadjusted_ext( ModuleOrUniformRoot::Module(module), @@ -483,6 +523,21 @@ impl<'a> Resolver<'a> { ); match binding { Ok(binding) => { + if let Some(lint_id) = derive_fallback_lint_id { + this.lint_buffer.buffer_lint_with_diagnostic( + PROC_MACRO_DERIVE_RESOLUTION_FALLBACK, + lint_id, + orig_ident.span, + &format!( + "cannot find {} `{}` in this scope", + ns.descr(), + ident + ), + BuiltinLintDiagnostics::ProcMacroDeriveResolutionFallback( + orig_ident.span, + ), + ); + } let misc_flags = if ptr::eq(module, this.graph_root) { Flags::MISC_SUGGEST_CRATE } else if module.is_normal() { diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs index f950e4a9bee65..1b181b714005b 100644 --- a/compiler/rustc_resolve/src/lib.rs +++ b/compiler/rustc_resolve/src/lib.rs @@ -105,7 +105,9 @@ enum Scope<'a> { DeriveHelpersCompat, MacroRules(MacroRulesScopeRef<'a>), CrateRoot, - Module(Module<'a>), + // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK` + // lint if it should be reported. + Module(Module<'a>, Option), MacroUsePrelude, BuiltinAttrs, ExternPrelude, @@ -1591,7 +1593,7 @@ impl<'a> Resolver<'a> { self.visit_scopes(ScopeSet::All(TypeNS, false), parent_scope, ctxt, |this, scope, _, _| { match scope { - Scope::Module(module) => { + Scope::Module(module, _) => { this.traits_in_module(module, assoc_item, &mut found_traits); } Scope::StdLibPrelude => { diff --git a/tests/ui/proc-macro/generate-mod.rs b/tests/ui/proc-macro/generate-mod.rs index 9eea630c310ec..471f317edf964 100644 --- a/tests/ui/proc-macro/generate-mod.rs +++ b/tests/ui/proc-macro/generate-mod.rs @@ -15,16 +15,19 @@ struct S; #[derive(generate_mod::CheckDerive)] //~ ERROR cannot find type `FromOutside` in this scope //~| ERROR cannot find type `OuterDerive` in this scope + //~| WARN this was previously accepted + //~| WARN this was previously accepted struct Z; fn inner_block() { #[derive(generate_mod::CheckDerive)] //~ ERROR cannot find type `FromOutside` in this scope //~| ERROR cannot find type `OuterDerive` in this scope + //~| WARN this was previously accepted + //~| WARN this was previously accepted struct InnerZ; } -#[derive(generate_mod::CheckDeriveLint)] //~ ERROR cannot find type `OuterDeriveLint` in this scope - //~| ERROR cannot find type `FromOutside` in this scope +#[derive(generate_mod::CheckDeriveLint)] // OK, lint is suppressed struct W; fn main() {} diff --git a/tests/ui/proc-macro/generate-mod.stderr b/tests/ui/proc-macro/generate-mod.stderr index 2c55abf38c399..db629b5b5e239 100644 --- a/tests/ui/proc-macro/generate-mod.stderr +++ b/tests/ui/proc-macro/generate-mod.stderr @@ -38,66 +38,127 @@ LL | #[generate_mod::check_attr] OuterAttr = note: this error originates in the attribute macro `generate_mod::check_attr` (in Nightly builds, run with -Z macro-backtrace for more info) -error[E0412]: cannot find type `FromOutside` in this scope +error: cannot find type `FromOutside` in this scope --> $DIR/generate-mod.rs:16:10 | LL | #[derive(generate_mod::CheckDerive)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import | - = help: consider importing this struct: - FromOutside + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 + = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) -error[E0412]: cannot find type `OuterDerive` in this scope +error: cannot find type `OuterDerive` in this scope --> $DIR/generate-mod.rs:16:10 | LL | #[derive(generate_mod::CheckDerive)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import | - = help: consider importing this struct: - OuterDerive + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) -error[E0412]: cannot find type `FromOutside` in this scope - --> $DIR/generate-mod.rs:21:14 +error: cannot find type `FromOutside` in this scope + --> $DIR/generate-mod.rs:23:14 | LL | #[derive(generate_mod::CheckDerive)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import | - = help: consider importing this struct: - FromOutside + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) -error[E0412]: cannot find type `OuterDerive` in this scope - --> $DIR/generate-mod.rs:21:14 +error: cannot find type `OuterDerive` in this scope + --> $DIR/generate-mod.rs:23:14 | LL | #[derive(generate_mod::CheckDerive)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import | - = help: consider importing this struct: - OuterDerive + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) -error[E0412]: cannot find type `FromOutside` in this scope - --> $DIR/generate-mod.rs:26:10 +error: aborting due to 8 previous errors + +For more information about this error, try `rustc --explain E0412`. +Future incompatibility report: Future breakage diagnostic: +error: cannot find type `FromOutside` in this scope + --> $DIR/generate-mod.rs:16:10 | -LL | #[derive(generate_mod::CheckDeriveLint)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope +LL | #[derive(generate_mod::CheckDerive)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import | - = help: consider importing this struct: - FromOutside - = note: this error originates in the derive macro `generate_mod::CheckDeriveLint` (in Nightly builds, run with -Z macro-backtrace for more info) + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 + = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default + = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) -error[E0412]: cannot find type `OuterDeriveLint` in this scope - --> $DIR/generate-mod.rs:26:10 +Future breakage diagnostic: +error: cannot find type `OuterDerive` in this scope + --> $DIR/generate-mod.rs:16:10 | -LL | #[derive(generate_mod::CheckDeriveLint)] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope +LL | #[derive(generate_mod::CheckDerive)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import | - = help: consider importing this struct: - OuterDeriveLint - = note: this error originates in the derive macro `generate_mod::CheckDeriveLint` (in Nightly builds, run with -Z macro-backtrace for more info) + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 + = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default + = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) -error: aborting due to 10 previous errors +Future breakage diagnostic: +error: cannot find type `FromOutside` in this scope + --> $DIR/generate-mod.rs:23:14 + | +LL | #[derive(generate_mod::CheckDerive)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 + = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default + = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) + +Future breakage diagnostic: +error: cannot find type `OuterDerive` in this scope + --> $DIR/generate-mod.rs:23:14 + | +LL | #[derive(generate_mod::CheckDerive)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 + = note: `#[deny(proc_macro_derive_resolution_fallback)]` on by default + = note: this error originates in the derive macro `generate_mod::CheckDerive` (in Nightly builds, run with -Z macro-backtrace for more info) + +Future breakage diagnostic: +warning: cannot find type `FromOutside` in this scope + --> $DIR/generate-mod.rs:30:10 + | +LL | #[derive(generate_mod::CheckDeriveLint)] // OK, lint is suppressed + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 +note: the lint level is defined here + --> $DIR/generate-mod.rs:30:10 + | +LL | #[derive(generate_mod::CheckDeriveLint)] // OK, lint is suppressed + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + = note: this warning originates in the derive macro `generate_mod::CheckDeriveLint` (in Nightly builds, run with -Z macro-backtrace for more info) + +Future breakage diagnostic: +warning: cannot find type `OuterDeriveLint` in this scope + --> $DIR/generate-mod.rs:30:10 + | +LL | #[derive(generate_mod::CheckDeriveLint)] // OK, lint is suppressed + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ names from parent modules are not accessible without an explicit import + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #83583 +note: the lint level is defined here + --> $DIR/generate-mod.rs:30:10 + | +LL | #[derive(generate_mod::CheckDeriveLint)] // OK, lint is suppressed + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + = note: this warning originates in the derive macro `generate_mod::CheckDeriveLint` (in Nightly builds, run with -Z macro-backtrace for more info) -For more information about this error, try `rustc --explain E0412`.