diff options
Diffstat (limited to 'compiler/rustc_resolve/src/macros.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/macros.rs | 145 |
1 files changed, 80 insertions, 65 deletions
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs index d76db7c645a..6d3fde33f4d 100644 --- a/compiler/rustc_resolve/src/macros.rs +++ b/compiler/rustc_resolve/src/macros.rs @@ -14,8 +14,7 @@ use rustc_data_structures::fx::FxHashSet; use rustc_data_structures::ptr_key::PtrKey; use rustc_data_structures::sync::Lrc; use rustc_errors::struct_span_err; -use rustc_expand::base::{Indeterminate, InvocationRes, ResolverExpand}; -use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind}; +use rustc_expand::base::{Indeterminate, ResolverExpand, SyntaxExtension, SyntaxExtensionKind}; use rustc_expand::compile_declarative_macro; use rustc_expand::expand::{AstFragment, Invocation, InvocationKind}; use rustc_feature::is_builtin_attr_name; @@ -24,7 +23,8 @@ use rustc_hir::def_id; use rustc_hir::PrimTy; use rustc_middle::middle::stability; use rustc_middle::ty; -use rustc_session::lint::builtin::{SOFT_UNSTABLE, UNUSED_MACROS}; +use rustc_session::lint::builtin::{LEGACY_DERIVE_HELPERS, SOFT_UNSTABLE, UNUSED_MACROS}; +use rustc_session::lint::BuiltinLintDiagnostics; use rustc_session::parse::feature_err; use rustc_session::Session; use rustc_span::edition::Edition; @@ -227,7 +227,7 @@ impl<'a> ResolverExpand for Resolver<'a> { invoc: &Invocation, eager_expansion_root: ExpnId, force: bool, - ) -> Result<InvocationRes, Indeterminate> { + ) -> Result<Lrc<SyntaxExtension>, Indeterminate> { let invoc_id = invoc.expansion_data.id; let parent_scope = match self.invocation_parent_scopes.get(&invoc_id) { Some(parent_scope) => *parent_scope, @@ -244,65 +244,15 @@ impl<'a> ResolverExpand for Resolver<'a> { } }; - let (path, kind, inner_attr, derives, after_derive) = match invoc.kind { - InvocationKind::Attr { ref attr, ref derives, after_derive, .. } => ( + let (path, kind, inner_attr, derives) = match invoc.kind { + InvocationKind::Attr { ref attr, ref derives, .. } => ( &attr.get_normal_item().path, MacroKind::Attr, attr.style == ast::AttrStyle::Inner, self.arenas.alloc_ast_paths(derives), - after_derive, ), - InvocationKind::Bang { ref mac, .. } => { - (&mac.path, MacroKind::Bang, false, &[][..], false) - } - InvocationKind::Derive { ref path, .. } => { - (path, MacroKind::Derive, false, &[][..], false) - } - InvocationKind::DeriveContainer { ref derives, .. } => { - // Block expansion of the container until we resolve all derives in it. - // This is required for two reasons: - // - Derive helper attributes are in scope for the item to which the `#[derive]` - // is applied, so they have to be produced by the container's expansion rather - // than by individual derives. - // - Derives in the container need to know whether one of them is a built-in `Copy`. - // FIXME: Try to avoid repeated resolutions for derives here and in expansion. - let mut exts = Vec::new(); - let mut helper_attrs = Vec::new(); - for path in derives { - exts.push( - match self.resolve_macro_path( - path, - Some(MacroKind::Derive), - &parent_scope, - true, - force, - ) { - Ok((Some(ext), _)) => { - let span = path - .segments - .last() - .unwrap() - .ident - .span - .normalize_to_macros_2_0(); - helper_attrs.extend( - ext.helper_attrs.iter().map(|name| Ident::new(*name, span)), - ); - if ext.builtin_name == Some(sym::Copy) { - self.containers_deriving_copy.insert(invoc_id); - } - ext - } - Ok(_) | Err(Determinacy::Determined) => { - self.dummy_ext(MacroKind::Derive) - } - Err(Determinacy::Undetermined) => return Err(Indeterminate), - }, - ) - } - self.helper_attrs.insert(invoc_id, helper_attrs); - return Ok(InvocationRes::DeriveContainer(exts)); - } + InvocationKind::Bang { ref mac, .. } => (&mac.path, MacroKind::Bang, false, &[][..]), + InvocationKind::Derive { ref path, .. } => (path, MacroKind::Derive, false, &[][..]), }; // Derives are not included when `invocations` are collected, so we have to add them here. @@ -328,14 +278,11 @@ impl<'a> ResolverExpand for Resolver<'a> { )); if let Res::Def(_, _) = res { - if after_derive { - self.session.span_err(span, "macro attributes must be placed before `#[derive]`"); - } let normal_module_def_id = self.macro_def_scope(invoc_id).nearest_parent_mod; self.definitions.add_parent_module_of_macro_def(invoc_id, normal_module_def_id); } - Ok(InvocationRes::Single(ext)) + Ok(ext) } fn check_unused_macros(&mut self) { @@ -344,7 +291,7 @@ impl<'a> ResolverExpand for Resolver<'a> { } } - fn lint_node_id(&mut self, expn_id: ExpnId) -> NodeId { + fn lint_node_id(&self, expn_id: ExpnId) -> NodeId { // FIXME - make this more precise. This currently returns the NodeId of the // nearest closing item - we should try to return the closest parent of the ExpnId self.invocation_parents @@ -356,6 +303,63 @@ impl<'a> ResolverExpand for Resolver<'a> { self.containers_deriving_copy.contains(&expn_id) } + fn resolve_derives( + &mut self, + expn_id: ExpnId, + derives: Vec<ast::Path>, + force: bool, + ) -> Result<(), Indeterminate> { + // Block expansion of the container until we resolve all derives in it. + // This is required for two reasons: + // - Derive helper attributes are in scope for the item to which the `#[derive]` + // is applied, so they have to be produced by the container's expansion rather + // than by individual derives. + // - Derives in the container need to know whether one of them is a built-in `Copy`. + // FIXME: Try to cache intermediate results to avoid resolving same derives multiple times. + let parent_scope = self.invocation_parent_scopes[&expn_id]; + let mut exts = Vec::new(); + let mut helper_attrs = Vec::new(); + let mut has_derive_copy = false; + for path in derives { + exts.push(( + match self.resolve_macro_path( + &path, + Some(MacroKind::Derive), + &parent_scope, + true, + force, + ) { + Ok((Some(ext), _)) => { + let span = + path.segments.last().unwrap().ident.span.normalize_to_macros_2_0(); + helper_attrs + .extend(ext.helper_attrs.iter().map(|name| Ident::new(*name, span))); + has_derive_copy |= ext.builtin_name == Some(sym::Copy); + ext + } + Ok(_) | Err(Determinacy::Determined) => self.dummy_ext(MacroKind::Derive), + Err(Determinacy::Undetermined) => return Err(Indeterminate), + }, + path, + )) + } + self.derive_resolutions.insert(expn_id, exts); + self.helper_attrs.insert(expn_id, helper_attrs); + // Mark this derive as having `Copy` either if it has `Copy` itself or if its parent derive + // has `Copy`, to support cases like `#[derive(Clone, Copy)] #[derive(Debug)]`. + if has_derive_copy || self.has_derive_copy(parent_scope.expansion) { + self.containers_deriving_copy.insert(expn_id); + } + Ok(()) + } + + fn take_derive_resolutions( + &mut self, + expn_id: ExpnId, + ) -> Option<Vec<(Lrc<SyntaxExtension>, ast::Path)>> { + self.derive_resolutions.remove(&expn_id) + } + // The function that implements the resolution logic of `#[cfg_accessible(path)]`. // Returns true if the path can certainly be resolved in one of three namespaces, // returns false if the path certainly cannot be resolved in any of the three namespaces. @@ -818,6 +822,8 @@ impl<'a> Resolver<'a> { let is_builtin = |res| { matches!(res, Res::NonMacroAttr(NonMacroAttrKind::Builtin(..))) }; + let derive_helper = + Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper); let derive_helper_compat = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat); @@ -826,7 +832,7 @@ impl<'a> Resolver<'a> { } else if is_builtin(innermost_res) || is_builtin(res) { Some(AmbiguityKind::BuiltinAttr) } else if innermost_res == derive_helper_compat - || res == derive_helper_compat + || res == derive_helper_compat && innermost_res != derive_helper { Some(AmbiguityKind::DeriveHelper) } else if innermost_flags.contains(Flags::MACRO_RULES) @@ -992,6 +998,15 @@ impl<'a> Resolver<'a> { let res = binding.res(); let seg = Segment::from_ident(ident); check_consistency(self, &[seg], ident.span, kind, initial_res, res); + if res == Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat) { + self.lint_buffer.buffer_lint_with_diagnostic( + LEGACY_DERIVE_HELPERS, + self.lint_node_id(parent_scope.expansion), + ident.span, + "derive helper attribute is used before it is introduced", + BuiltinLintDiagnostics::LegacyDeriveHelpers(binding.span), + ); + } } Err(..) => { let expected = kind.descr_expected(); @@ -1078,7 +1093,7 @@ impl<'a> Resolver<'a> { crate fn check_reserved_macro_name(&mut self, ident: Ident, res: Res) { // Reserve some names that are not quite covered by the general check // performed on `Resolver::builtin_attrs`. - if ident.name == sym::cfg || ident.name == sym::cfg_attr || ident.name == sym::derive { + if ident.name == sym::cfg || ident.name == sym::cfg_attr { let macro_kind = self.get_macro(res).map(|ext| ext.macro_kind()); if macro_kind.is_some() && sub_namespace_match(macro_kind, Some(MacroKind::Attr)) { self.session.span_err( |