Sync rustc_codegen_cranelift 'ddd4ce25535cf71203ba3700896131ce55fde795'

[rust.git] / compiler / rustc_ast / src / ast_like.rs

diff --git a/compiler/rustc_ast/src/ast_like.rs b/compiler/rustc_ast/src/ast_like.rs
index 63bc7c49a99956b1858e796bfb0a84671433d742..945a44ab66371ccbae0b8e3cec39975ae5168396 100644 (file)
--- a/compiler/rustc_ast/src/ast_like.rs
+++ b/compiler/rustc_ast/src/ast_like.rs
@@ -1,20 +1,32 @@
 use super::ptr::P;
+use super::token::Nonterminal;
 use super::tokenstream::LazyTokenStream;
 use super::{Arm, ExprField, FieldDef, GenericParam, Param, PatField, Variant};
-use super::{AssocItem, Expr, ForeignItem, Item, Local};
+use super::{AssocItem, Expr, ForeignItem, Item, Local, MacCallStmt};
 use super::{AttrItem, AttrKind, Block, Pat, Path, Ty, Visibility};
 use super::{AttrVec, Attribute, Stmt, StmtKind};
 
+use std::fmt::Debug;
+
 /// An `AstLike` represents an AST node (or some wrapper around
 /// and AST node) which stores some combination of attributes
 /// and tokens.
-pub trait AstLike: Sized {
+pub trait AstLike: Sized + Debug {
+    /// This is `true` if this `AstLike` might support 'custom' (proc-macro) inner
+    /// attributes. Attributes like `#![cfg]` and `#![cfg_attr]` are not
+    /// considered 'custom' attributes
+    ///
+    /// If this is `false`, then this `AstLike` definitely does
+    /// not support 'custom' inner attributes, which enables some optimizations
+    /// during token collection.
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool;
     fn attrs(&self) -> &[Attribute];
     fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>));
     fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>>;
 }
 
 impl<T: AstLike + 'static> AstLike for P<T> {
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = T::SUPPORTS_CUSTOM_INNER_ATTRS;
     fn attrs(&self) -> &[Attribute] {
         (**self).attrs()
     }
@@ -26,6 +38,55 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
     }
 }
 
+impl AstLike for crate::token::Nonterminal {
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = true;
+    fn attrs(&self) -> &[Attribute] {
+        match self {
+            Nonterminal::NtItem(item) => item.attrs(),
+            Nonterminal::NtStmt(stmt) => stmt.attrs(),
+            Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.attrs(),
+            Nonterminal::NtPat(_)
+            | Nonterminal::NtTy(_)
+            | Nonterminal::NtMeta(_)
+            | Nonterminal::NtPath(_)
+            | Nonterminal::NtVis(_)
+            | Nonterminal::NtTT(_)
+            | Nonterminal::NtBlock(_)
+            | Nonterminal::NtIdent(..)
+            | Nonterminal::NtLifetime(_) => &[],
+        }
+    }
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
+        match self {
+            Nonterminal::NtItem(item) => item.visit_attrs(f),
+            Nonterminal::NtStmt(stmt) => stmt.visit_attrs(f),
+            Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.visit_attrs(f),
+            Nonterminal::NtPat(_)
+            | Nonterminal::NtTy(_)
+            | Nonterminal::NtMeta(_)
+            | Nonterminal::NtPath(_)
+            | Nonterminal::NtVis(_)
+            | Nonterminal::NtTT(_)
+            | Nonterminal::NtBlock(_)
+            | Nonterminal::NtIdent(..)
+            | Nonterminal::NtLifetime(_) => {}
+        }
+    }
+    fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
+        match self {
+            Nonterminal::NtItem(item) => item.tokens_mut(),
+            Nonterminal::NtStmt(stmt) => stmt.tokens_mut(),
+            Nonterminal::NtExpr(expr) | Nonterminal::NtLiteral(expr) => expr.tokens_mut(),
+            Nonterminal::NtPat(pat) => pat.tokens_mut(),
+            Nonterminal::NtTy(ty) => ty.tokens_mut(),
+            Nonterminal::NtMeta(attr_item) => attr_item.tokens_mut(),
+            Nonterminal::NtPath(path) => path.tokens_mut(),
+            Nonterminal::NtVis(vis) => vis.tokens_mut(),
+            _ => panic!("Called tokens_mut on {:?}", self),
+        }
+    }
+}
+
 fn visit_attrvec(attrs: &mut AttrVec, f: impl FnOnce(&mut Vec<Attribute>)) {
     crate::mut_visit::visit_clobber(attrs, |attrs| {
         let mut vec = attrs.into();
@@ -35,6 +96,10 @@ fn visit_attrvec(attrs: &mut AttrVec, f: impl FnOnce(&mut Vec<Attribute>)) {
 }
 
 impl AstLike for StmtKind {
+    // This might be an `StmtKind::Item`, which contains
+    // an item that supports inner attrs
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = true;
+
     fn attrs(&self) -> &[Attribute] {
         match self {
             StmtKind::Local(local) => local.attrs(),
@@ -66,6 +131,8 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
 }
 
 impl AstLike for Stmt {
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = StmtKind::SUPPORTS_CUSTOM_INNER_ATTRS;
+
     fn attrs(&self) -> &[Attribute] {
         self.kind.attrs()
     }
@@ -79,6 +146,8 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
 }
 
 impl AstLike for Attribute {
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = false;
+
     fn attrs(&self) -> &[Attribute] {
         &[]
     }
@@ -94,6 +163,8 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
 }
 
 impl<T: AstLike> AstLike for Option<T> {
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = T::SUPPORTS_CUSTOM_INNER_ATTRS;
+
     fn attrs(&self) -> &[Attribute] {
         self.as_ref().map(|inner| inner.attrs()).unwrap_or(&[])
     }
@@ -127,8 +198,13 @@ fn visit(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
 }
 
 macro_rules! derive_has_tokens_and_attrs {
-    ($($ty:path),*) => { $(
+    (
+        const SUPPORTS_CUSTOM_INNER_ATTRS: bool = $inner_attrs:literal;
+        $($ty:path),*
+    ) => { $(
         impl AstLike for $ty {
+            const SUPPORTS_CUSTOM_INNER_ATTRS: bool = $inner_attrs;
+
             fn attrs(&self) -> &[Attribute] {
                 &self.attrs
             }
@@ -140,6 +216,7 @@ fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
             fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
                 Some(&mut self.tokens)
             }
+
         }
     )* }
 }
@@ -147,6 +224,8 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
 macro_rules! derive_has_attrs_no_tokens {
     ($($ty:path),*) => { $(
         impl AstLike for $ty {
+            const SUPPORTS_CUSTOM_INNER_ATTRS: bool = false;
+
             fn attrs(&self) -> &[Attribute] {
                 &self.attrs
             }
@@ -165,12 +244,13 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
 macro_rules! derive_has_tokens_no_attrs {
     ($($ty:path),*) => { $(
         impl AstLike for $ty {
+            const SUPPORTS_CUSTOM_INNER_ATTRS: bool = false;
+
             fn attrs(&self) -> &[Attribute] {
                 &[]
             }
 
             fn visit_attrs(&mut self, _f: impl FnOnce(&mut Vec<Attribute>)) {}
-
             fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
                 Some(&mut self.tokens)
             }
@@ -178,10 +258,18 @@ fn tokens_mut(&mut self) -> Option<&mut Option<LazyTokenStream>> {
     )* }
 }
 
-// These AST nodes support both inert and active
-// attributes, so they also have tokens.
+// These ast nodes support both active and inert attributes,
+// so they have tokens collected to pass to proc macros
+derive_has_tokens_and_attrs! {
+    // Both `Item` and `AssocItem` can have bodies, which
+    // can contain inner attributes
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = true;
+    Item, AssocItem, ForeignItem
+}
+
 derive_has_tokens_and_attrs! {
-    Item, Expr, Local, AssocItem, ForeignItem
+    const SUPPORTS_CUSTOM_INNER_ATTRS: bool = false;
+    Local, MacCallStmt, Expr
 }
 
 // These ast nodes only support inert attributes, so they don't