diff options
Diffstat (limited to 'src/libsyntax/ext/base.rs')
| -rw-r--r-- | src/libsyntax/ext/base.rs | 145 |
1 files changed, 110 insertions, 35 deletions
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs index b0a4a6af983..5d68983d7cb 100644 --- a/src/libsyntax/ext/base.rs +++ b/src/libsyntax/ext/base.rs @@ -1,16 +1,17 @@ use crate::ast::{self, NodeId, Attribute, Name, PatKind}; -use crate::attr::{HasAttrs, Stability, Deprecation}; +use crate::attr::{self, HasAttrs, Stability, Deprecation}; use crate::source_map::SourceMap; use crate::edition::Edition; use crate::ext::expand::{self, AstFragment, Invocation}; -use crate::ext::hygiene::{ExpnId, SyntaxContext, Transparency}; +use crate::ext::hygiene::{ExpnId, Transparency}; use crate::mut_visit::{self, MutVisitor}; -use crate::parse::{self, parser, DirectoryOwnership}; +use crate::parse::{self, parser, ParseSess, DirectoryOwnership}; use crate::parse::token; use crate::ptr::P; use crate::symbol::{kw, sym, Ident, Symbol}; use crate::{ThinVec, MACRO_ARGUMENTS}; use crate::tokenstream::{self, TokenStream, TokenTree}; +use crate::visit::Visitor; use errors::{DiagnosticBuilder, DiagnosticId}; use smallvec::{smallvec, SmallVec}; @@ -72,6 +73,17 @@ impl Annotatable { } } + pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) { + match self { + Annotatable::Item(item) => visitor.visit_item(item), + Annotatable::TraitItem(trait_item) => visitor.visit_trait_item(trait_item), + Annotatable::ImplItem(impl_item) => visitor.visit_impl_item(impl_item), + Annotatable::ForeignItem(foreign_item) => visitor.visit_foreign_item(foreign_item), + Annotatable::Stmt(stmt) => visitor.visit_stmt(stmt), + Annotatable::Expr(expr) => visitor.visit_expr(expr), + } + } + pub fn expect_item(self) -> P<ast::Item> { match self { Annotatable::Item(i) => i, @@ -549,8 +561,6 @@ pub struct SyntaxExtension { pub kind: SyntaxExtensionKind, /// Span of the macro definition. pub span: Span, - /// Hygienic properties of spans produced by this macro by default. - pub default_transparency: Transparency, /// Whitelist of unstable features that are treated as stable inside this macro. pub allow_internal_unstable: Option<Lrc<[Symbol]>>, /// Suppresses the `unsafe_code` lint for code produced by this macro. @@ -572,22 +582,6 @@ pub struct SyntaxExtension { pub is_derive_copy: bool, } -impl SyntaxExtensionKind { - /// When a syntax extension is constructed, - /// its transparency can often be inferred from its kind. - fn default_transparency(&self) -> Transparency { - match self { - SyntaxExtensionKind::Bang(..) | - SyntaxExtensionKind::Attr(..) | - SyntaxExtensionKind::Derive(..) | - SyntaxExtensionKind::NonMacroAttr { .. } => Transparency::Opaque, - SyntaxExtensionKind::LegacyBang(..) | - SyntaxExtensionKind::LegacyAttr(..) | - SyntaxExtensionKind::LegacyDerive(..) => Transparency::SemiTransparent, - } - } -} - impl SyntaxExtension { /// Returns which kind of macro calls this syntax extension. pub fn macro_kind(&self) -> MacroKind { @@ -606,7 +600,6 @@ impl SyntaxExtension { pub fn default(kind: SyntaxExtensionKind, edition: Edition) -> SyntaxExtension { SyntaxExtension { span: DUMMY_SP, - default_transparency: kind.default_transparency(), allow_internal_unstable: None, allow_internal_unsafe: false, local_inner_macros: false, @@ -620,6 +613,69 @@ impl SyntaxExtension { } } + /// Constructs a syntax extension with the given properties + /// and other properties converted from attributes. + pub fn new( + sess: &ParseSess, + kind: SyntaxExtensionKind, + span: Span, + helper_attrs: Vec<Symbol>, + edition: Edition, + name: Name, + attrs: &[ast::Attribute], + ) -> SyntaxExtension { + let allow_internal_unstable = + attr::find_by_name(attrs, sym::allow_internal_unstable).map(|attr| { + attr.meta_item_list() + .map(|list| { + list.iter() + .filter_map(|it| { + let name = it.ident().map(|ident| ident.name); + if name.is_none() { + sess.span_diagnostic.span_err( + it.span(), "allow internal unstable expects feature names" + ) + } + name + }) + .collect::<Vec<Symbol>>() + .into() + }) + .unwrap_or_else(|| { + sess.span_diagnostic.span_warn( + attr.span, + "allow_internal_unstable expects list of feature names. In the future \ + this will become a hard error. Please use `allow_internal_unstable(\ + foo, bar)` to only allow the `foo` and `bar` features", + ); + vec![sym::allow_internal_unstable_backcompat_hack].into() + }) + }); + + let mut local_inner_macros = false; + if let Some(macro_export) = attr::find_by_name(attrs, sym::macro_export) { + if let Some(l) = macro_export.meta_item_list() { + local_inner_macros = attr::list_contains_name(&l, sym::local_inner_macros); + } + } + + let is_builtin = attr::contains_name(attrs, sym::rustc_builtin_macro); + + SyntaxExtension { + kind, + span, + allow_internal_unstable, + allow_internal_unsafe: attr::contains_name(attrs, sym::allow_internal_unsafe), + local_inner_macros, + stability: attr::find_stability(&sess, attrs, span), + deprecation: attr::find_deprecation(&sess, attrs, span), + helper_attrs, + edition, + is_builtin, + is_derive_copy: is_builtin && name == sym::Copy, + } + } + pub fn dummy_bang(edition: Edition) -> SyntaxExtension { fn expander<'cx>(_: &'cx mut ExtCtxt<'_>, span: Span, _: &[TokenTree]) -> Box<dyn MacResult + 'cx> { @@ -646,7 +702,6 @@ impl SyntaxExtension { parent, call_site, def_site: self.span, - default_transparency: self.default_transparency, allow_internal_unstable: self.allow_internal_unstable.clone(), allow_internal_unsafe: self.allow_internal_unsafe, local_inner_macros: self.local_inner_macros, @@ -657,6 +712,12 @@ impl SyntaxExtension { pub type NamedSyntaxExtension = (Name, SyntaxExtension); +/// Result of resolving a macro invocation. +pub enum InvocationRes { + Single(Lrc<SyntaxExtension>), + DeriveContainer(Vec<Lrc<SyntaxExtension>>), +} + /// Error type that denotes indeterminacy. pub struct Indeterminate; @@ -682,8 +743,9 @@ pub trait Resolver { fn resolve_imports(&mut self); - fn resolve_macro_invocation(&mut self, invoc: &Invocation, invoc_id: ExpnId, force: bool) - -> Result<Option<Lrc<SyntaxExtension>>, Indeterminate>; + fn resolve_macro_invocation( + &mut self, invoc: &Invocation, eager_expansion_root: ExpnId, force: bool + ) -> Result<InvocationRes, Indeterminate>; fn check_unused_macros(&self); @@ -759,23 +821,39 @@ impl<'a> ExtCtxt<'a> { pub fn call_site(&self) -> Span { self.current_expansion.id.expn_data().call_site } - pub fn backtrace(&self) -> SyntaxContext { - SyntaxContext::root().apply_mark(self.current_expansion.id) + + /// 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_ctxt_from_mark(self.current_expansion.id, Transparency::Opaque) + } + + /// 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_ctxt_from_mark(self.current_expansion.id, Transparency::Transparent) + } + + /// Span with a context reproducing `macro_rules` hygiene (hygienic locals, unhygienic items). + /// FIXME: This should be eventually replaced either with `with_def_site_ctxt` (preferably), + /// or with `with_call_site_ctxt` (where necessary). + pub fn with_legacy_ctxt(&self, span: Span) -> Span { + span.with_ctxt_from_mark(self.current_expansion.id, Transparency::SemiTransparent) } /// Returns span for the macro which originally caused the current expansion to happen. /// /// Stops backtracing at include! boundary. pub fn expansion_cause(&self) -> Option<Span> { - let mut ctxt = self.backtrace(); + let mut expn_id = self.current_expansion.id; let mut last_macro = None; loop { - let expn_data = ctxt.outer_expn_data(); + let expn_data = expn_id.expn_data(); // Stop going up the backtrace once include! is encountered if expn_data.is_root() || expn_data.kind.descr() == sym::include { break; } - ctxt = expn_data.call_site.ctxt(); + expn_id = expn_data.call_site.ctxt().outer_expn(); last_macro = Some(expn_data.call_site); } last_macro @@ -864,7 +942,7 @@ impl<'a> ExtCtxt<'a> { ast::Ident::from_str(st) } pub fn std_path(&self, components: &[Symbol]) -> Vec<ast::Ident> { - let def_site = DUMMY_SP.apply_mark(self.current_expansion.id); + 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() @@ -908,12 +986,9 @@ impl<'a> ExtCtxt<'a> { /// compilation on error, merely emits a non-fatal error and returns `None`. pub fn expr_to_spanned_string<'a>( cx: &'a mut ExtCtxt<'_>, - mut expr: P<ast::Expr>, + expr: P<ast::Expr>, err_msg: &str, ) -> Result<(Symbol, ast::StrStyle, Span), Option<DiagnosticBuilder<'a>>> { - // Update `expr.span`'s ctxt now in case expr is an `include!` macro invocation. - expr.span = expr.span.apply_mark(cx.current_expansion.id); - // 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(); |