use crate::expand::{self, AstFragment, Invocation}; use crate::module::DirOwnership; use rustc_ast::attr::MarkedAttrs; use rustc_ast::ptr::P; use rustc_ast::token::{self, Nonterminal}; use rustc_ast::tokenstream::TokenStream; use rustc_ast::visit::{AssocCtxt, Visitor}; use rustc_ast::{self as ast, AttrVec, Attribute, HasAttrs, Item, NodeId, PatKind}; use rustc_attr::{self as attr, Deprecation, Stability}; use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; use rustc_data_structures::sync::{self, Lrc}; use rustc_errors::{ Applicability, DiagnosticBuilder, ErrorGuaranteed, IntoDiagnostic, MultiSpan, PResult, }; use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT; use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics}; use rustc_parse::{self, parser, MACRO_ARGUMENTS}; use rustc_session::{parse::ParseSess, Limit, Session}; use rustc_span::def_id::{CrateNum, DefId, LocalDefId}; use rustc_span::edition::Edition; use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId}; use rustc_span::source_map::SourceMap; use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{BytePos, FileName, RealFileName, Span, DUMMY_SP}; use smallvec::{smallvec, SmallVec}; use std::default::Default; use std::iter; use std::path::PathBuf; use std::rc::Rc; pub(crate) use rustc_span::hygiene::MacroKind; // When adding new variants, make sure to // adjust the `visit_*` / `flat_map_*` calls in `InvocationCollector` // to use `assign_id!` #[derive(Debug, Clone)] pub enum Annotatable { Item(P), TraitItem(P), ImplItem(P), ForeignItem(P), Stmt(P), Expr(P), Arm(ast::Arm), ExprField(ast::ExprField), PatField(ast::PatField), GenericParam(ast::GenericParam), Param(ast::Param), FieldDef(ast::FieldDef), Variant(ast::Variant), Crate(ast::Crate), } impl Annotatable { pub fn span(&self) -> Span { match *self { Annotatable::Item(ref item) => item.span, Annotatable::TraitItem(ref trait_item) => trait_item.span, Annotatable::ImplItem(ref impl_item) => impl_item.span, Annotatable::ForeignItem(ref foreign_item) => foreign_item.span, Annotatable::Stmt(ref stmt) => stmt.span, Annotatable::Expr(ref expr) => expr.span, Annotatable::Arm(ref arm) => arm.span, Annotatable::ExprField(ref field) => field.span, Annotatable::PatField(ref fp) => fp.pat.span, Annotatable::GenericParam(ref gp) => gp.ident.span, Annotatable::Param(ref p) => p.span, Annotatable::FieldDef(ref sf) => sf.span, Annotatable::Variant(ref v) => v.span, Annotatable::Crate(ref c) => c.spans.inner_span, } } pub fn visit_attrs(&mut self, f: impl FnOnce(&mut AttrVec)) { match self { Annotatable::Item(item) => item.visit_attrs(f), Annotatable::TraitItem(trait_item) => trait_item.visit_attrs(f), Annotatable::ImplItem(impl_item) => impl_item.visit_attrs(f), Annotatable::ForeignItem(foreign_item) => foreign_item.visit_attrs(f), Annotatable::Stmt(stmt) => stmt.visit_attrs(f), Annotatable::Expr(expr) => expr.visit_attrs(f), Annotatable::Arm(arm) => arm.visit_attrs(f), Annotatable::ExprField(field) => field.visit_attrs(f), Annotatable::PatField(fp) => fp.visit_attrs(f), Annotatable::GenericParam(gp) => gp.visit_attrs(f), Annotatable::Param(p) => p.visit_attrs(f), Annotatable::FieldDef(sf) => sf.visit_attrs(f), Annotatable::Variant(v) => v.visit_attrs(f), Annotatable::Crate(c) => c.visit_attrs(f), } } pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) { match self { Annotatable::Item(item) => visitor.visit_item(item), Annotatable::TraitItem(item) => visitor.visit_assoc_item(item, AssocCtxt::Trait), Annotatable::ImplItem(item) => visitor.visit_assoc_item(item, AssocCtxt::Impl), Annotatable::ForeignItem(foreign_item) => visitor.visit_foreign_item(foreign_item), Annotatable::Stmt(stmt) => visitor.visit_stmt(stmt), Annotatable::Expr(expr) => visitor.visit_expr(expr), Annotatable::Arm(arm) => visitor.visit_arm(arm), Annotatable::ExprField(field) => visitor.visit_expr_field(field), Annotatable::PatField(fp) => visitor.visit_pat_field(fp), Annotatable::GenericParam(gp) => visitor.visit_generic_param(gp), Annotatable::Param(p) => visitor.visit_param(p), Annotatable::FieldDef(sf) => visitor.visit_field_def(sf), Annotatable::Variant(v) => visitor.visit_variant(v), Annotatable::Crate(c) => visitor.visit_crate(c), } } pub fn to_tokens(&self) -> TokenStream { match self { Annotatable::Item(node) => TokenStream::from_ast(node), Annotatable::TraitItem(node) | Annotatable::ImplItem(node) => { TokenStream::from_ast(node) } Annotatable::ForeignItem(node) => TokenStream::from_ast(node), Annotatable::Stmt(node) => { assert!(!matches!(node.kind, ast::StmtKind::Empty)); TokenStream::from_ast(node) } Annotatable::Expr(node) => TokenStream::from_ast(node), Annotatable::Arm(..) | Annotatable::ExprField(..) | Annotatable::PatField(..) | Annotatable::GenericParam(..) | Annotatable::Param(..) | Annotatable::FieldDef(..) | Annotatable::Variant(..) | Annotatable::Crate(..) => panic!("unexpected annotatable"), } } pub fn expect_item(self) -> P { match self { Annotatable::Item(i) => i, _ => panic!("expected Item"), } } pub fn expect_trait_item(self) -> P { match self { Annotatable::TraitItem(i) => i, _ => panic!("expected Item"), } } pub fn expect_impl_item(self) -> P { match self { Annotatable::ImplItem(i) => i, _ => panic!("expected Item"), } } pub fn expect_foreign_item(self) -> P { match self { Annotatable::ForeignItem(i) => i, _ => panic!("expected foreign item"), } } pub fn expect_stmt(self) -> ast::Stmt { match self { Annotatable::Stmt(stmt) => stmt.into_inner(), _ => panic!("expected statement"), } } pub fn expect_expr(self) -> P { match self { Annotatable::Expr(expr) => expr, _ => panic!("expected expression"), } } pub fn expect_arm(self) -> ast::Arm { match self { Annotatable::Arm(arm) => arm, _ => panic!("expected match arm"), } } pub fn expect_expr_field(self) -> ast::ExprField { match self { Annotatable::ExprField(field) => field, _ => panic!("expected field"), } } pub fn expect_pat_field(self) -> ast::PatField { match self { Annotatable::PatField(fp) => fp, _ => panic!("expected field pattern"), } } pub fn expect_generic_param(self) -> ast::GenericParam { match self { Annotatable::GenericParam(gp) => gp, _ => panic!("expected generic parameter"), } } pub fn expect_param(self) -> ast::Param { match self { Annotatable::Param(param) => param, _ => panic!("expected parameter"), } } pub fn expect_field_def(self) -> ast::FieldDef { match self { Annotatable::FieldDef(sf) => sf, _ => panic!("expected struct field"), } } pub fn expect_variant(self) -> ast::Variant { match self { Annotatable::Variant(v) => v, _ => panic!("expected variant"), } } pub fn expect_crate(self) -> ast::Crate { match self { Annotatable::Crate(krate) => krate, _ => panic!("expected krate"), } } } /// Result of an expansion that may need to be retried. /// Consider using this for non-`MultiItemModifier` expanders as well. pub enum ExpandResult { /// Expansion produced a result (possibly dummy). Ready(T), /// Expansion could not produce a result and needs to be retried. Retry(U), } // `meta_item` is the attribute, and `item` is the item being modified. pub trait MultiItemModifier { fn expand( &self, ecx: &mut ExtCtxt<'_>, span: Span, meta_item: &ast::MetaItem, item: Annotatable, ) -> ExpandResult, Annotatable>; } impl MultiItemModifier for F where F: Fn(&mut ExtCtxt<'_>, Span, &ast::MetaItem, Annotatable) -> Vec, { fn expand( &self, ecx: &mut ExtCtxt<'_>, span: Span, meta_item: &ast::MetaItem, item: Annotatable, ) -> ExpandResult, Annotatable> { ExpandResult::Ready(self(ecx, span, meta_item, item)) } } pub trait BangProcMacro { fn expand<'cx>( &self, ecx: &'cx mut ExtCtxt<'_>, span: Span, ts: TokenStream, ) -> Result; } impl BangProcMacro for F where F: Fn(TokenStream) -> TokenStream, { fn expand<'cx>( &self, _ecx: &'cx mut ExtCtxt<'_>, _span: Span, ts: TokenStream, ) -> Result { // FIXME setup implicit context in TLS before calling self. Ok(self(ts)) } } pub trait AttrProcMacro { fn expand<'cx>( &self, ecx: &'cx mut ExtCtxt<'_>, span: Span, annotation: TokenStream, annotated: TokenStream, ) -> Result; } impl AttrProcMacro for F where F: Fn(TokenStream, TokenStream) -> TokenStream, { fn expand<'cx>( &self, _ecx: &'cx mut ExtCtxt<'_>, _span: Span, annotation: TokenStream, annotated: TokenStream, ) -> Result { // FIXME setup implicit context in TLS before calling self. Ok(self(annotation, annotated)) } } /// Represents a thing that maps token trees to Macro Results pub trait TTMacroExpander { fn expand<'cx>( &self, ecx: &'cx mut ExtCtxt<'_>, span: Span, input: TokenStream, ) -> Box; } pub type MacroExpanderFn = for<'cx> fn(&'cx mut ExtCtxt<'_>, Span, TokenStream) -> Box; impl TTMacroExpander for F where F: for<'cx> Fn(&'cx mut ExtCtxt<'_>, Span, TokenStream) -> Box, { fn expand<'cx>( &self, ecx: &'cx mut ExtCtxt<'_>, span: Span, input: TokenStream, ) -> Box { self(ecx, span, input) } } // Use a macro because forwarding to a simple function has type system issues macro_rules! make_stmts_default { ($me:expr) => { $me.make_expr().map(|e| { smallvec![ast::Stmt { id: ast::DUMMY_NODE_ID, span: e.span, kind: ast::StmtKind::Expr(e), }] }) }; } /// The result of a macro expansion. The return values of the various /// methods are spliced into the AST at the callsite of the macro. pub trait MacResult { /// Creates an expression. fn make_expr(self: Box) -> Option> { None } /// Creates zero or more items. fn make_items(self: Box) -> Option; 1]>> { None } /// Creates zero or more impl items. fn make_impl_items(self: Box) -> Option; 1]>> { None } /// Creates zero or more trait items. fn make_trait_items(self: Box) -> Option; 1]>> { None } /// Creates zero or more items in an `extern {}` block fn make_foreign_items(self: Box) -> Option; 1]>> { None } /// Creates a pattern. fn make_pat(self: Box) -> Option> { None } /// Creates zero or more statements. /// /// By default this attempts to create an expression statement, /// returning None if that fails. fn make_stmts(self: Box) -> Option> { make_stmts_default!(self) } fn make_ty(self: Box) -> Option> { None } fn make_arms(self: Box) -> Option> { None } fn make_expr_fields(self: Box) -> Option> { None } fn make_pat_fields(self: Box) -> Option> { None } fn make_generic_params(self: Box) -> Option> { None } fn make_params(self: Box) -> Option> { None } fn make_field_defs(self: Box) -> Option> { None } fn make_variants(self: Box) -> Option> { None } fn make_crate(self: Box) -> Option { // Fn-like macros cannot produce a crate. unreachable!() } } macro_rules! make_MacEager { ( $( $fld:ident: $t:ty, )* ) => { /// `MacResult` implementation for the common case where you've already /// built each form of AST that you might return. #[derive(Default)] pub struct MacEager { $( pub $fld: Option<$t>, )* } impl MacEager { $( pub fn $fld(v: $t) -> Box { Box::new(MacEager { $fld: Some(v), ..Default::default() }) } )* } } } make_MacEager! { expr: P, pat: P, items: SmallVec<[P; 1]>, impl_items: SmallVec<[P; 1]>, trait_items: SmallVec<[P; 1]>, foreign_items: SmallVec<[P; 1]>, stmts: SmallVec<[ast::Stmt; 1]>, ty: P, } impl MacResult for MacEager { fn make_expr(self: Box) -> Option> { self.expr } fn make_items(self: Box) -> Option; 1]>> { self.items } fn make_impl_items(self: Box) -> Option; 1]>> { self.impl_items } fn make_trait_items(self: Box) -> Option; 1]>> { self.trait_items } fn make_foreign_items(self: Box) -> Option; 1]>> { self.foreign_items } fn make_stmts(self: Box) -> Option> { match self.stmts.as_ref().map_or(0, |s| s.len()) { 0 => make_stmts_default!(self), _ => self.stmts, } } fn make_pat(self: Box) -> Option> { if let Some(p) = self.pat { return Some(p); } if let Some(e) = self.expr { if let ast::ExprKind::Lit(_) = e.kind { return Some(P(ast::Pat { id: ast::DUMMY_NODE_ID, span: e.span, kind: PatKind::Lit(e), tokens: None, })); } } None } fn make_ty(self: Box) -> Option> { self.ty } } /// Fill-in macro expansion result, to allow compilation to continue /// after hitting errors. #[derive(Copy, Clone)] pub struct DummyResult { is_error: bool, span: Span, } impl DummyResult { /// Creates a default MacResult that can be anything. /// /// Use this as a return value after hitting any errors and /// calling `span_err`. pub fn any(span: Span) -> Box { Box::new(DummyResult { is_error: true, span }) } /// Same as `any`, but must be a valid fragment, not error. pub fn any_valid(span: Span) -> Box { Box::new(DummyResult { is_error: false, span }) } /// A plain dummy expression. pub fn raw_expr(sp: Span, is_error: bool) -> P { P(ast::Expr { id: ast::DUMMY_NODE_ID, kind: if is_error { ast::ExprKind::Err } else { ast::ExprKind::Tup(Vec::new()) }, span: sp, attrs: ast::AttrVec::new(), tokens: None, }) } /// A plain dummy pattern. pub fn raw_pat(sp: Span) -> ast::Pat { ast::Pat { id: ast::DUMMY_NODE_ID, kind: PatKind::Wild, span: sp, tokens: None } } /// A plain dummy type. pub fn raw_ty(sp: Span, is_error: bool) -> P { P(ast::Ty { id: ast::DUMMY_NODE_ID, kind: if is_error { ast::TyKind::Err } else { ast::TyKind::Tup(Vec::new()) }, span: sp, tokens: None, }) } } impl MacResult for DummyResult { fn make_expr(self: Box) -> Option> { Some(DummyResult::raw_expr(self.span, self.is_error)) } fn make_pat(self: Box) -> Option> { Some(P(DummyResult::raw_pat(self.span))) } fn make_items(self: Box) -> Option; 1]>> { Some(SmallVec::new()) } fn make_impl_items(self: Box) -> Option; 1]>> { Some(SmallVec::new()) } fn make_trait_items(self: Box) -> Option; 1]>> { Some(SmallVec::new()) } fn make_foreign_items(self: Box) -> Option; 1]>> { Some(SmallVec::new()) } fn make_stmts(self: Box) -> Option> { Some(smallvec![ast::Stmt { id: ast::DUMMY_NODE_ID, kind: ast::StmtKind::Expr(DummyResult::raw_expr(self.span, self.is_error)), span: self.span, }]) } fn make_ty(self: Box) -> Option> { Some(DummyResult::raw_ty(self.span, self.is_error)) } fn make_arms(self: Box) -> Option> { Some(SmallVec::new()) } fn make_expr_fields(self: Box) -> Option> { Some(SmallVec::new()) } fn make_pat_fields(self: Box) -> Option> { Some(SmallVec::new()) } fn make_generic_params(self: Box) -> Option> { Some(SmallVec::new()) } fn make_params(self: Box) -> Option> { Some(SmallVec::new()) } fn make_field_defs(self: Box) -> Option> { Some(SmallVec::new()) } fn make_variants(self: Box) -> Option> { Some(SmallVec::new()) } } /// A syntax extension kind. pub enum SyntaxExtensionKind { /// A token-based function-like macro. Bang( /// An expander with signature TokenStream -> TokenStream. Box, ), /// An AST-based function-like macro. LegacyBang( /// An expander with signature TokenStream -> AST. Box, ), /// A token-based attribute macro. Attr( /// An expander with signature (TokenStream, TokenStream) -> TokenStream. /// The first TokenSteam is the attribute itself, the second is the annotated item. /// The produced TokenSteam replaces the input TokenSteam. Box, ), /// An AST-based attribute macro. LegacyAttr( /// An expander with signature (AST, AST) -> AST. /// The first AST fragment is the attribute itself, the second is the annotated item. /// The produced AST fragment replaces the input AST fragment. Box, ), /// A trivial attribute "macro" that does nothing, /// only keeps the attribute and marks it as inert, /// thus making it ineligible for further expansion. NonMacroAttr, /// A token-based derive macro. Derive( /// An expander with signature TokenStream -> TokenStream (not yet). /// The produced TokenSteam is appended to the input TokenSteam. Box, ), /// An AST-based derive macro. LegacyDerive( /// An expander with signature AST -> AST. /// The produced AST fragment is appended to the input AST fragment. Box, ), } /// A struct representing a macro definition in "lowered" form ready for expansion. pub struct SyntaxExtension { /// A syntax extension kind. pub kind: SyntaxExtensionKind, /// Span of the macro definition. pub span: Span, /// List of unstable features that are treated as stable inside this macro. pub allow_internal_unstable: Option>, /// The macro's stability info. pub stability: Option, /// The macro's deprecation info. pub deprecation: Option, /// Names of helper attributes registered by this macro. pub helper_attrs: Vec, /// Edition of the crate in which this macro is defined. pub edition: Edition, /// Built-in macros have a couple of special properties like availability /// in `#[no_implicit_prelude]` modules, so we have to keep this flag. pub builtin_name: Option, /// Suppresses the `unsafe_code` lint for code produced by this macro. pub allow_internal_unsafe: bool, /// Enables the macro helper hack (`ident!(...)` -> `$crate::ident!(...)`) for this macro. pub local_inner_macros: bool, /// Should debuginfo for the macro be collapsed to the outermost expansion site (in other /// words, was the macro definition annotated with `#[collapse_debuginfo]`)? pub collapse_debuginfo: bool, } impl SyntaxExtension { /// Returns which kind of macro calls this syntax extension. pub fn macro_kind(&self) -> MacroKind { match self.kind { SyntaxExtensionKind::Bang(..) | SyntaxExtensionKind::LegacyBang(..) => MacroKind::Bang, SyntaxExtensionKind::Attr(..) | SyntaxExtensionKind::LegacyAttr(..) | SyntaxExtensionKind::NonMacroAttr => MacroKind::Attr, SyntaxExtensionKind::Derive(..) | SyntaxExtensionKind::LegacyDerive(..) => { MacroKind::Derive } } } /// Constructs a syntax extension with default properties. pub fn default(kind: SyntaxExtensionKind, edition: Edition) -> SyntaxExtension { SyntaxExtension { span: DUMMY_SP, allow_internal_unstable: None, stability: None, deprecation: None, helper_attrs: Vec::new(), edition, builtin_name: None, kind, allow_internal_unsafe: false, local_inner_macros: false, collapse_debuginfo: false, } } /// Constructs a syntax extension with the given properties /// and other properties converted from attributes. pub fn new( sess: &Session, kind: SyntaxExtensionKind, span: Span, helper_attrs: Vec, edition: Edition, name: Symbol, attrs: &[ast::Attribute], ) -> SyntaxExtension { let allow_internal_unstable = attr::allow_internal_unstable(sess, &attrs).collect::>(); let allow_internal_unsafe = sess.contains_name(attrs, sym::allow_internal_unsafe); let local_inner_macros = sess .find_by_name(attrs, sym::macro_export) .and_then(|macro_export| macro_export.meta_item_list()) .map_or(false, |l| attr::list_contains_name(&l, sym::local_inner_macros)); let collapse_debuginfo = sess.contains_name(attrs, sym::collapse_debuginfo); tracing::debug!(?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe); let (builtin_name, helper_attrs) = sess .find_by_name(attrs, sym::rustc_builtin_macro) .map(|attr| { // Override `helper_attrs` passed above if it's a built-in macro, // marking `proc_macro_derive` macros as built-in is not a realistic use case. parse_macro_name_and_helper_attrs(sess.diagnostic(), attr, "built-in").map_or_else( || (Some(name), Vec::new()), |(name, helper_attrs)| (Some(name), helper_attrs), ) }) .unwrap_or_else(|| (None, helper_attrs)); let (stability, const_stability, body_stability) = attr::find_stability(&sess, attrs, span); if let Some((_, sp)) = const_stability { sess.parse_sess .span_diagnostic .struct_span_err(sp, "macros cannot have const stability attributes") .span_label(sp, "invalid const stability attribute") .span_label( sess.source_map().guess_head_span(span), "const stability attribute affects this macro", ) .emit(); } if let Some((_, sp)) = body_stability { sess.parse_sess .span_diagnostic .struct_span_err(sp, "macros cannot have body stability attributes") .span_label(sp, "invalid body stability attribute") .span_label( sess.source_map().guess_head_span(span), "body stability attribute affects this macro", ) .emit(); } SyntaxExtension { kind, span, allow_internal_unstable: (!allow_internal_unstable.is_empty()) .then(|| allow_internal_unstable.into()), stability: stability.map(|(s, _)| s), deprecation: attr::find_deprecation(&sess, attrs).map(|(d, _)| d), helper_attrs, edition, builtin_name, allow_internal_unsafe, local_inner_macros, collapse_debuginfo, } } pub fn dummy_bang(edition: Edition) -> SyntaxExtension { fn expander<'cx>( _: &'cx mut ExtCtxt<'_>, span: Span, _: TokenStream, ) -> Box { DummyResult::any(span) } SyntaxExtension::default(SyntaxExtensionKind::LegacyBang(Box::new(expander)), edition) } pub fn dummy_derive(edition: Edition) -> SyntaxExtension { fn expander( _: &mut ExtCtxt<'_>, _: Span, _: &ast::MetaItem, _: Annotatable, ) -> Vec { Vec::new() } SyntaxExtension::default(SyntaxExtensionKind::Derive(Box::new(expander)), edition) } pub fn non_macro_attr(edition: Edition) -> SyntaxExtension { SyntaxExtension::default(SyntaxExtensionKind::NonMacroAttr, edition) } pub fn expn_data( &self, parent: LocalExpnId, call_site: Span, descr: Symbol, macro_def_id: Option, parent_module: Option, ) -> ExpnData { ExpnData::new( ExpnKind::Macro(self.macro_kind(), descr), parent.to_expn_id(), call_site, self.span, self.allow_internal_unstable.clone(), self.edition, macro_def_id, parent_module, self.allow_internal_unsafe, self.local_inner_macros, self.collapse_debuginfo, ) } } /// Error type that denotes indeterminacy. pub struct Indeterminate; pub type DeriveResolutions = Vec<(ast::Path, Annotatable, Option>)>; pub trait ResolverExpand { fn next_node_id(&mut self) -> NodeId; fn invocation_parent(&self, id: LocalExpnId) -> LocalDefId; fn resolve_dollar_crates(&mut self); fn visit_ast_fragment_with_placeholders( &mut self, expn_id: LocalExpnId, fragment: &AstFragment, ); fn register_builtin_macro(&mut self, name: Symbol, ext: SyntaxExtensionKind); fn expansion_for_ast_pass( &mut self, call_site: Span, pass: AstPass, features: &[Symbol], parent_module_id: Option, ) -> LocalExpnId; fn resolve_imports(&mut self); fn resolve_macro_invocation( &mut self, invoc: &Invocation, eager_expansion_root: LocalExpnId, force: bool, ) -> Result, Indeterminate>; fn record_macro_rule_usage(&mut self, mac_id: NodeId, rule_index: usize); fn check_unused_macros(&mut self); // Resolver interfaces for specific built-in macros. /// Does `#[derive(...)]` attribute with the given `ExpnId` have built-in `Copy` inside it? fn has_derive_copy(&self, expn_id: LocalExpnId) -> bool; /// Resolve paths inside the `#[derive(...)]` attribute with the given `ExpnId`. fn resolve_derives( &mut self, expn_id: LocalExpnId, force: bool, derive_paths: &dyn Fn() -> DeriveResolutions, ) -> Result<(), Indeterminate>; /// Take resolutions for paths inside the `#[derive(...)]` attribute with the given `ExpnId` /// back from resolver. fn take_derive_resolutions(&mut self, expn_id: LocalExpnId) -> Option; /// Path resolution logic for `#[cfg_accessible(path)]`. fn cfg_accessible( &mut self, expn_id: LocalExpnId, path: &ast::Path, ) -> Result; /// Decodes the proc-macro quoted span in the specified crate, with the specified id. /// No caching is performed. fn get_proc_macro_quoted_span(&self, krate: CrateNum, id: usize) -> Span; /// The order of items in the HIR is unrelated to the order of /// items in the AST. However, we generate proc macro harnesses /// based on the AST order, and later refer to these harnesses /// from the HIR. This field keeps track of the order in which /// we generated proc macros harnesses, so that we can map /// HIR proc macros items back to their harness items. fn declare_proc_macro(&mut self, id: NodeId); /// Tools registered with `#![register_tool]` and used by tool attributes and lints. fn registered_tools(&self) -> &FxHashSet; } pub trait LintStoreExpand { fn pre_expansion_lint( &self, sess: &Session, registered_tools: &FxHashSet, node_id: NodeId, attrs: &[Attribute], items: &[P], name: &str, ); } type LintStoreExpandDyn<'a> = Option<&'a (dyn LintStoreExpand + 'a)>; #[derive(Clone, Default)] pub struct ModuleData { /// Path to the module starting from the crate name, like `my_crate::foo::bar`. pub mod_path: Vec, /// Stack of paths to files loaded by out-of-line module items, /// used to detect and report recursive module inclusions. pub file_path_stack: Vec, /// Directory to search child module files in, /// often (but not necessarily) the parent of the top file path on the `file_path_stack`. pub dir_path: PathBuf, } impl ModuleData { pub fn with_dir_path(&self, dir_path: PathBuf) -> ModuleData { ModuleData { mod_path: self.mod_path.clone(), file_path_stack: self.file_path_stack.clone(), dir_path, } } } #[derive(Clone)] pub struct ExpansionData { pub id: LocalExpnId, pub depth: usize, pub module: Rc, pub dir_ownership: DirOwnership, pub prior_type_ascription: Option<(Span, bool)>, /// Some parent node that is close to this macro call pub lint_node_id: NodeId, pub is_trailing_mac: bool, } /// One of these is made during expansion and incrementally updated as we go; /// when a macro expansion occurs, the resulting nodes have the `backtrace() /// -> expn_data` of their expansion context stored into their span. pub struct ExtCtxt<'a> { pub sess: &'a Session, pub ecfg: expand::ExpansionConfig<'a>, pub reduced_recursion_limit: Option, pub root_path: PathBuf, pub resolver: &'a mut dyn ResolverExpand, pub current_expansion: ExpansionData, /// Error recovery mode entered when expansion is stuck /// (or during eager expansion, but that's a hack). pub force_mode: bool, pub expansions: FxIndexMap>, /// Used for running pre-expansion lints on freshly loaded modules. pub(super) lint_store: LintStoreExpandDyn<'a>, /// Used for storing lints generated during expansion, like `NAMED_ARGUMENTS_USED_POSITIONALLY` pub buffered_early_lint: Vec, /// When we 'expand' an inert attribute, we leave it /// in the AST, but insert it here so that we know /// not to expand it again. pub(super) expanded_inert_attrs: MarkedAttrs, } impl<'a> ExtCtxt<'a> { pub fn new( sess: &'a Session, ecfg: expand::ExpansionConfig<'a>, resolver: &'a mut dyn ResolverExpand, lint_store: LintStoreExpandDyn<'a>, ) -> ExtCtxt<'a> { ExtCtxt { sess, ecfg, reduced_recursion_limit: None, resolver, lint_store, root_path: PathBuf::new(), current_expansion: ExpansionData { id: LocalExpnId::ROOT, depth: 0, module: Default::default(), dir_ownership: DirOwnership::Owned { relative: None }, prior_type_ascription: None, lint_node_id: ast::CRATE_NODE_ID, is_trailing_mac: false, }, force_mode: false, expansions: FxIndexMap::default(), expanded_inert_attrs: MarkedAttrs::new(), buffered_early_lint: vec![], } } /// Returns a `Folder` for deeply expanding all macros in an AST node. pub fn expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> { expand::MacroExpander::new(self, false) } /// Returns a `Folder` that deeply expands all macros and assigns all `NodeId`s in an AST node. /// Once `NodeId`s are assigned, the node may not be expanded, removed, or otherwise modified. pub fn monotonic_expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> { expand::MacroExpander::new(self, true) } pub fn new_parser_from_tts(&self, stream: TokenStream) -> parser::Parser<'a> { rustc_parse::stream_to_parser(&self.sess.parse_sess, stream, MACRO_ARGUMENTS) } pub fn source_map(&self) -> &'a SourceMap { self.sess.parse_sess.source_map() } pub fn parse_sess(&self) -> &'a ParseSess { &self.sess.parse_sess } pub fn call_site(&self) -> Span { self.current_expansion.id.expn_data().call_site } /// Returns the current expansion kind's description. pub(crate) fn expansion_descr(&self) -> String { let expn_data = self.current_expansion.id.expn_data(); expn_data.kind.descr() } /// Equivalent of `Span::def_site` from the proc macro API, /// except that the location is taken from the span passed as an argument. pub fn with_def_site_ctxt(&self, span: Span) -> Span { span.with_def_site_ctxt(self.current_expansion.id.to_expn_id()) } /// Equivalent of `Span::call_site` from the proc macro API, /// except that the location is taken from the span passed as an argument. pub fn with_call_site_ctxt(&self, span: Span) -> Span { span.with_call_site_ctxt(self.current_expansion.id.to_expn_id()) } /// Equivalent of `Span::mixed_site` from the proc macro API, /// except that the location is taken from the span passed as an argument. pub fn with_mixed_site_ctxt(&self, span: Span) -> Span { span.with_mixed_site_ctxt(self.current_expansion.id.to_expn_id()) } /// Returns span for the macro which originally caused the current expansion to happen. /// /// Stops backtracing at include! boundary. pub fn expansion_cause(&self) -> Option { self.current_expansion.id.expansion_cause() } #[rustc_lint_diagnostics] pub fn struct_span_err>( &self, sp: S, msg: &str, ) -> DiagnosticBuilder<'a, ErrorGuaranteed> { self.sess.parse_sess.span_diagnostic.struct_span_err(sp, msg) } pub fn create_err( &self, err: impl IntoDiagnostic<'a>, ) -> DiagnosticBuilder<'a, ErrorGuaranteed> { self.sess.create_err(err) } pub fn emit_err(&self, err: impl IntoDiagnostic<'a>) -> ErrorGuaranteed { self.sess.emit_err(err) } /// Emit `msg` attached to `sp`, without immediately stopping /// compilation. /// /// Compilation will be stopped in the near future (at the end of /// the macro expansion phase). #[rustc_lint_diagnostics] pub fn span_err>(&self, sp: S, msg: &str) { self.sess.parse_sess.span_diagnostic.span_err(sp, msg); } #[rustc_lint_diagnostics] pub fn span_warn>(&self, sp: S, msg: &str) { self.sess.parse_sess.span_diagnostic.span_warn(sp, msg); } pub fn span_bug>(&self, sp: S, msg: &str) -> ! { self.sess.parse_sess.span_diagnostic.span_bug(sp, msg); } pub fn trace_macros_diag(&mut self) { for (sp, notes) in self.expansions.iter() { let mut db = self.sess.parse_sess.span_diagnostic.span_note_diag(*sp, "trace_macro"); for note in notes { db.note(note); } db.emit(); } // Fixme: does this result in errors? self.expansions.clear(); } pub fn bug(&self, msg: &str) -> ! { self.sess.parse_sess.span_diagnostic.bug(msg); } pub fn trace_macros(&self) -> bool { self.ecfg.trace_mac } pub fn set_trace_macros(&mut self, x: bool) { self.ecfg.trace_mac = x } pub fn std_path(&self, components: &[Symbol]) -> Vec { let def_site = self.with_def_site_ctxt(DUMMY_SP); iter::once(Ident::new(kw::DollarCrate, def_site)) .chain(components.iter().map(|&s| Ident::with_dummy_span(s))) .collect() } pub fn def_site_path(&self, components: &[Symbol]) -> Vec { let def_site = self.with_def_site_ctxt(DUMMY_SP); components.iter().map(|&s| Ident::new(s, def_site)).collect() } pub fn check_unused_macros(&mut self) { self.resolver.check_unused_macros(); } } /// Resolves a `path` mentioned inside Rust code, returning an absolute path. /// /// This unifies the logic used for resolving `include_X!`. pub fn resolve_path( parse_sess: &ParseSess, path: impl Into, span: Span, ) -> PResult<'_, PathBuf> { let path = path.into(); // Relative paths are resolved relative to the file in which they are found // after macro expansion (that is, they are unhygienic). if !path.is_absolute() { let callsite = span.source_callsite(); let mut result = match parse_sess.source_map().span_to_filename(callsite) { FileName::Real(name) => name .into_local_path() .expect("attempting to resolve a file path in an external file"), FileName::DocTest(path, _) => path, other => { return Err(parse_sess.span_diagnostic.struct_span_err( span, &format!( "cannot resolve relative path in non-file source `{}`", parse_sess.source_map().filename_for_diagnostics(&other) ), )); } }; result.pop(); result.push(path); Ok(result) } else { Ok(path) } } /// Extracts a string literal from the macro expanded version of `expr`, /// returning a diagnostic error of `err_msg` if `expr` is not a string literal. /// The returned bool indicates whether an applicable suggestion has already been /// added to the diagnostic to avoid emitting multiple suggestions. `Err(None)` /// indicates that an ast error was encountered. pub fn expr_to_spanned_string<'a>( cx: &'a mut ExtCtxt<'_>, expr: P, err_msg: &str, ) -> Result<(Symbol, ast::StrStyle, Span), Option<(DiagnosticBuilder<'a, ErrorGuaranteed>, bool)>> { // Perform eager expansion on the expression. // We want to be able to handle e.g., `concat!("foo", "bar")`. let expr = cx.expander().fully_expand_fragment(AstFragment::Expr(expr)).make_expr(); Err(match expr.kind { ast::ExprKind::Lit(ref l) => match l.kind { ast::LitKind::Str(s, style) => return Ok((s, style, expr.span)), ast::LitKind::ByteStr(_) => { let mut err = cx.struct_span_err(l.span, err_msg); let span = expr.span.shrink_to_lo(); err.span_suggestion( span.with_hi(span.lo() + BytePos(1)), "consider removing the leading `b`", "", Applicability::MaybeIncorrect, ); Some((err, true)) } ast::LitKind::Err => None, _ => Some((cx.struct_span_err(l.span, err_msg), false)), }, ast::ExprKind::Err => None, _ => Some((cx.struct_span_err(expr.span, err_msg), false)), }) } /// Extracts a string literal from the macro expanded version of `expr`, /// emitting `err_msg` if `expr` is not a string literal. This does not stop /// compilation on error, merely emits a non-fatal error and returns `None`. pub fn expr_to_string( cx: &mut ExtCtxt<'_>, expr: P, err_msg: &str, ) -> Option<(Symbol, ast::StrStyle)> { expr_to_spanned_string(cx, expr, err_msg) .map_err(|err| { err.map(|(mut err, _)| { err.emit(); }) }) .ok() .map(|(symbol, style, _)| (symbol, style)) } /// Non-fatally assert that `tts` is empty. Note that this function /// returns even when `tts` is non-empty, macros that *need* to stop /// compilation should call /// `cx.parse_sess.span_diagnostic.abort_if_errors()` (this should be /// done as rarely as possible). pub fn check_zero_tts(cx: &ExtCtxt<'_>, sp: Span, tts: TokenStream, name: &str) { if !tts.is_empty() { cx.span_err(sp, &format!("{} takes no arguments", name)); } } /// Parse an expression. On error, emit it, advancing to `Eof`, and return `None`. pub fn parse_expr(p: &mut parser::Parser<'_>) -> Option> { match p.parse_expr() { Ok(e) => return Some(e), Err(mut err) => { err.emit(); } } while p.token != token::Eof { p.bump(); } None } /// Interpreting `tts` as a comma-separated sequence of expressions, /// expect exactly one string literal, or emit an error and return `None`. pub fn get_single_str_from_tts( cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream, name: &str, ) -> Option { let mut p = cx.new_parser_from_tts(tts); if p.token == token::Eof { cx.span_err(sp, &format!("{} takes 1 argument", name)); return None; } let ret = parse_expr(&mut p)?; let _ = p.eat(&token::Comma); if p.token != token::Eof { cx.span_err(sp, &format!("{} takes 1 argument", name)); } expr_to_string(cx, ret, "argument must be a string literal").map(|(s, _)| s) } /// Extracts comma-separated expressions from `tts`. /// On error, emit it, and return `None`. pub fn get_exprs_from_tts( cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream, ) -> Option>> { let mut p = cx.new_parser_from_tts(tts); let mut es = Vec::new(); while p.token != token::Eof { let expr = parse_expr(&mut p)?; // Perform eager expansion on the expression. // We want to be able to handle e.g., `concat!("foo", "bar")`. let expr = cx.expander().fully_expand_fragment(AstFragment::Expr(expr)).make_expr(); es.push(expr); if p.eat(&token::Comma) { continue; } if p.token != token::Eof { cx.span_err(sp, "expected token: `,`"); return None; } } Some(es) } pub fn parse_macro_name_and_helper_attrs( diag: &rustc_errors::Handler, attr: &Attribute, descr: &str, ) -> Option<(Symbol, Vec)> { // Once we've located the `#[proc_macro_derive]` attribute, verify // that it's of the form `#[proc_macro_derive(Foo)]` or // `#[proc_macro_derive(Foo, attributes(A, ..))]` let list = attr.meta_item_list()?; if list.len() != 1 && list.len() != 2 { diag.span_err(attr.span, "attribute must have either one or two arguments"); return None; } let Some(trait_attr) = list[0].meta_item() else { diag.span_err(list[0].span(), "not a meta item"); return None; }; let trait_ident = match trait_attr.ident() { Some(trait_ident) if trait_attr.is_word() => trait_ident, _ => { diag.span_err(trait_attr.span, "must only be one word"); return None; } }; if !trait_ident.name.can_be_raw() { diag.span_err( trait_attr.span, &format!("`{}` cannot be a name of {} macro", trait_ident, descr), ); } let attributes_attr = list.get(1); let proc_attrs: Vec<_> = if let Some(attr) = attributes_attr { if !attr.has_name(sym::attributes) { diag.span_err(attr.span(), "second argument must be `attributes`"); } attr.meta_item_list() .unwrap_or_else(|| { diag.span_err(attr.span(), "attribute must be of form: `attributes(foo, bar)`"); &[] }) .iter() .filter_map(|attr| { let Some(attr) = attr.meta_item() else { diag.span_err(attr.span(), "not a meta item"); return None; }; let ident = match attr.ident() { Some(ident) if attr.is_word() => ident, _ => { diag.span_err(attr.span, "must only be one word"); return None; } }; if !ident.name.can_be_raw() { diag.span_err( attr.span, &format!("`{}` cannot be a name of derive helper attribute", ident), ); } Some(ident.name) }) .collect() } else { Vec::new() }; Some((trait_ident.name, proc_attrs)) } /// This nonterminal looks like some specific enums from /// `proc-macro-hack` and `procedural-masquerade` crates. /// We need to maintain some special pretty-printing behavior for them due to incorrect /// asserts in old versions of those crates and their wide use in the ecosystem. /// See issue #73345 for more details. /// FIXME(#73933): Remove this eventually. fn pretty_printing_compatibility_hack(item: &Item, sess: &ParseSess) -> bool { let name = item.ident.name; if name == sym::ProceduralMasqueradeDummyType { if let ast::ItemKind::Enum(enum_def, _) = &item.kind { if let [variant] = &*enum_def.variants { if variant.ident.name == sym::Input { let filename = sess.source_map().span_to_filename(item.ident.span); if let FileName::Real(RealFileName::LocalPath(path)) = filename { if let Some(c) = path .components() .flat_map(|c| c.as_os_str().to_str()) .find(|c| c.starts_with("rental") || c.starts_with("allsorts-rental")) { let crate_matches = if c.starts_with("allsorts-rental") { true } else { let mut version = c.trim_start_matches("rental-").split("."); version.next() == Some("0") && version.next() == Some("5") && version .next() .and_then(|c| c.parse::().ok()) .map_or(false, |v| v < 6) }; if crate_matches { sess.buffer_lint_with_diagnostic( &PROC_MACRO_BACK_COMPAT, item.ident.span, ast::CRATE_NODE_ID, "using an old version of `rental`", BuiltinLintDiagnostics::ProcMacroBackCompat( "older versions of the `rental` crate will stop compiling in future versions of Rust; \ please update to `rental` v0.5.6, or switch to one of the `rental` alternatives".to_string() ) ); return true; } } } } } } } false } pub(crate) fn ann_pretty_printing_compatibility_hack(ann: &Annotatable, sess: &ParseSess) -> bool { let item = match ann { Annotatable::Item(item) => item, Annotatable::Stmt(stmt) => match &stmt.kind { ast::StmtKind::Item(item) => item, _ => return false, }, _ => return false, }; pretty_printing_compatibility_hack(item, sess) } pub(crate) fn nt_pretty_printing_compatibility_hack(nt: &Nonterminal, sess: &ParseSess) -> bool { let item = match nt { Nonterminal::NtItem(item) => item, Nonterminal::NtStmt(stmt) => match &stmt.kind { ast::StmtKind::Item(item) => item, _ => return false, }, _ => return false, }; pretty_printing_compatibility_hack(item, sess) }