Merge #6897

6897: Basic support for macros 2.0 r=jonas-schievink a=jonas-schievink

This adds support for (built-in-only) macros 2.0, and removes some hacks used for builtin derives, which are declared via macros 2.0 in libcore.

First steps for https://github.com/rust-analyzer/rust-analyzer/issues/2248.

Blocked on https://github.com/rust-analyzer/ungrammar/pull/16.

Co-authored-by: Jonas Schievink <[email protected]>
Co-authored-by: Jonas Schievink <[email protected]>

4 files changed, 106 insertions, 6 deletions

diff --git a/crates/syntax/src/ast.rs b/crates/syntax/src/ast.rs
index 7844f9ed6..70c568ea1 100644
--- a/crates/syntax/src/ast.rs
+++ b/crates/syntax/src/ast.rs
@@ -19,8 +19,8 @@ pub use self::{
     expr_ext::{ArrayExprKind, BinOp, Effect, ElseBranch, LiteralKind, PrefixOp, RangeOp},
     generated::{nodes::*, tokens::*},
     node_ext::{
-        AttrKind, FieldKind, NameOrNameRef, PathSegmentKind, SelfParamKind, SlicePatComponents,
-        StructKind, TypeBoundKind, VisibilityKind,
+        AttrKind, FieldKind, Macro, NameOrNameRef, PathSegmentKind, SelfParamKind,
+        SlicePatComponents, StructKind, TypeBoundKind, VisibilityKind,
     },
     token_ext::*,
     traits::*,
diff --git a/crates/syntax/src/ast/generated/nodes.rs b/crates/syntax/src/ast/generated/nodes.rs
index 0ad75214f..6eae323f4 100644
--- a/crates/syntax/src/ast/generated/nodes.rs
+++ b/crates/syntax/src/ast/generated/nodes.rs
@@ -286,6 +286,18 @@ impl MacroRules {
     pub fn token_tree(&self) -> Option<TokenTree> { support::child(&self.syntax) }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct MacroDef {
+    pub(crate) syntax: SyntaxNode,
+}
+impl ast::AttrsOwner for MacroDef {}
+impl ast::NameOwner for MacroDef {}
+impl ast::VisibilityOwner for MacroDef {}
+impl MacroDef {
+    pub fn macro_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![macro]) }
+    pub fn args(&self) -> Option<TokenTree> { support::child(&self.syntax) }
+    pub fn body(&self) -> Option<TokenTree> { support::child(&self.syntax) }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Module {
     pub(crate) syntax: SyntaxNode,
 }
@@ -1332,6 +1344,7 @@ pub enum Item {
     Impl(Impl),
     MacroCall(MacroCall),
     MacroRules(MacroRules),
+    MacroDef(MacroDef),
     Module(Module),
     Static(Static),
     Struct(Struct),
@@ -1689,6 +1702,17 @@ impl AstNode for MacroRules {
     }
     fn syntax(&self) -> &SyntaxNode { &self.syntax }
 }
+impl AstNode for MacroDef {
+    fn can_cast(kind: SyntaxKind) -> bool { kind == MACRO_DEF }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode { &self.syntax }
+}
 impl AstNode for Module {
     fn can_cast(kind: SyntaxKind) -> bool { kind == MODULE }
     fn cast(syntax: SyntaxNode) -> Option<Self> {
@@ -3086,6 +3110,9 @@ impl From<MacroCall> for Item {
 impl From<MacroRules> for Item {
     fn from(node: MacroRules) -> Item { Item::MacroRules(node) }
 }
+impl From<MacroDef> for Item {
+    fn from(node: MacroDef) -> Item { Item::MacroDef(node) }
+}
 impl From<Module> for Item {
     fn from(node: Module) -> Item { Item::Module(node) }
 }
@@ -3111,7 +3138,7 @@ impl AstNode for Item {
     fn can_cast(kind: SyntaxKind) -> bool {
         match kind {
             CONST | ENUM | EXTERN_BLOCK | EXTERN_CRATE | FN | IMPL | MACRO_CALL | MACRO_RULES
-            | MODULE | STATIC | STRUCT | TRAIT | TYPE_ALIAS | UNION | USE => true,
+            | MACRO_DEF | MODULE | STATIC | STRUCT | TRAIT | TYPE_ALIAS | UNION | USE => true,
             _ => false,
         }
     }
@@ -3125,6 +3152,7 @@ impl AstNode for Item {
             IMPL => Item::Impl(Impl { syntax }),
             MACRO_CALL => Item::MacroCall(MacroCall { syntax }),
             MACRO_RULES => Item::MacroRules(MacroRules { syntax }),
+            MACRO_DEF => Item::MacroDef(MacroDef { syntax }),
             MODULE => Item::Module(Module { syntax }),
             STATIC => Item::Static(Static { syntax }),
             STRUCT => Item::Struct(Struct { syntax }),
@@ -3146,6 +3174,7 @@ impl AstNode for Item {
             Item::Impl(it) => &it.syntax,
             Item::MacroCall(it) => &it.syntax,
             Item::MacroRules(it) => &it.syntax,
+            Item::MacroDef(it) => &it.syntax,
             Item::Module(it) => &it.syntax,
             Item::Static(it) => &it.syntax,
             Item::Struct(it) => &it.syntax,
@@ -3615,6 +3644,11 @@ impl std::fmt::Display for MacroRules {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
+impl std::fmt::Display for MacroDef {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(self.syntax(), f)
+    }
+}
 impl std::fmt::Display for Module {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
diff --git a/crates/syntax/src/ast/node_ext.rs b/crates/syntax/src/ast/node_ext.rs
index c59a29eab..40dec3c7f 100644
--- a/crates/syntax/src/ast/node_ext.rs
+++ b/crates/syntax/src/ast/node_ext.rs
@@ -3,6 +3,7 @@
 
 use std::fmt;
 
+use ast::AttrsOwner;
 use itertools::Itertools;
 use parser::SyntaxKind;
 
@@ -31,6 +32,57 @@ fn text_of_first_token(node: &SyntaxNode) -> &SmolStr {
     node.green().children().next().and_then(|it| it.into_token()).unwrap().text()
 }
 
+pub enum Macro {
+    MacroRules(ast::MacroRules),
+    MacroDef(ast::MacroDef),
+}
+
+impl From<ast::MacroRules> for Macro {
+    fn from(it: ast::MacroRules) -> Self {
+        Macro::MacroRules(it)
+    }
+}
+
+impl From<ast::MacroDef> for Macro {
+    fn from(it: ast::MacroDef) -> Self {
+        Macro::MacroDef(it)
+    }
+}
+
+impl AstNode for Macro {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            SyntaxKind::MACRO_RULES | SyntaxKind::MACRO_DEF => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        let res = match syntax.kind() {
+            SyntaxKind::MACRO_RULES => Macro::MacroRules(ast::MacroRules { syntax }),
+            SyntaxKind::MACRO_DEF => Macro::MacroDef(ast::MacroDef { syntax }),
+            _ => return None,
+        };
+        Some(res)
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        match self {
+            Macro::MacroRules(it) => it.syntax(),
+            Macro::MacroDef(it) => it.syntax(),
+        }
+    }
+}
+
+impl NameOwner for Macro {
+    fn name(&self) -> Option<ast::Name> {
+        match self {
+            Macro::MacroRules(mac) => mac.name(),
+            Macro::MacroDef(mac) => mac.name(),
+        }
+    }
+}
+
+impl AttrsOwner for Macro {}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum AttrKind {
     Inner,
@@ -462,4 +514,6 @@ impl ast::DocCommentsOwner for ast::Const {}
 impl ast::DocCommentsOwner for ast::TypeAlias {}
 impl ast::DocCommentsOwner for ast::Impl {}
 impl ast::DocCommentsOwner for ast::MacroRules {}
+impl ast::DocCommentsOwner for ast::MacroDef {}
+impl ast::DocCommentsOwner for ast::Macro {}
 impl ast::DocCommentsOwner for ast::Use {}
diff --git a/crates/syntax/src/display.rs b/crates/syntax/src/display.rs
index d33bde30c..391647fc6 100644
--- a/crates/syntax/src/display.rs
+++ b/crates/syntax/src/display.rs
@@ -76,8 +76,20 @@ pub fn type_label(node: &ast::TypeAlias) -> String {
     label.trim().to_owned()
 }
 
-pub fn macro_label(node: &ast::MacroRules) -> String {
+pub fn macro_label(node: &ast::Macro) -> String {
     let name = node.name().map(|name| name.syntax().text().to_string()).unwrap_or_default();
-    let vis = if node.has_atom_attr("macro_export") { "#[macro_export]\n" } else { "" };
-    format!("{}macro_rules! {}", vis, name)
+    match node {
+        ast::Macro::MacroRules(node) => {
+            let vis = if node.has_atom_attr("macro_export") { "#[macro_export]\n" } else { "" };
+            format!("{}macro_rules! {}", vis, name)
+        }
+        ast::Macro::MacroDef(node) => {
+            let mut s = String::new();
+            if let Some(vis) = node.visibility() {
+                format_to!(s, "{} ", vis);
+            }
+            format_to!(s, "macro {}", name);
+            s
+        }
+    }
 }