implement #[span]

Cargo.toml

@@ -30,3 +30,7 @@ features = [ "suggestions", "color" ]
 
 [profile.bench]
 debug = true
+
+
+[patch.crates-io]
+darling = { git = "https://github.com/kdy1/darling", branch = "proc-macro2-nightly" }

ecmascript/ast/src/decl.rs

@@ -12,13 +12,14 @@ pub enum Decl {
 #[ast_node]
 pub struct FnDecl {
     pub ident: Ident,
+    #[span]
     pub function: Function,
 }
 
 #[ast_node]
 pub struct ClassDecl {
     pub ident: Ident,
-
+    #[span]
     pub class: Class,
 }
 

ecmascript/ast/src/expr.rs

@@ -1,6 +1,6 @@
 use super::{AssignOp, BinaryOp, BlockStmt, Class, Function, Ident, Lit, Pat, Prop, UnaryOp,
             UpdateOp};
-use swc_common::Span;
+use swc_common::{Span, Spanned};
 use swc_macros::ast_node;
 
 #[ast_node]
@@ -114,7 +114,7 @@ pub struct BinExpr {
 #[ast_node]
 pub struct FnExpr {
     pub ident: Option<Ident>,
-
+    #[span]
     pub function: Function,
 }
 
@@ -122,7 +122,7 @@ pub struct FnExpr {
 #[ast_node]
 pub struct ClassExpr {
     pub ident: Option<Ident>,
-
+    #[span]
     pub class: Class,
 }
 
@@ -136,34 +136,42 @@ pub struct AssignExpr {
 
 #[ast_node]
 pub struct MemberExpr {
+    pub span: Span,
     pub obj: ExprOrSuper,
     pub prop: Box<Expr>,
     pub computed: bool,
 }
 #[ast_node]
 pub struct CondExpr {
+    #[span(lo)]
     pub test: Box<Expr>,
     pub cons: Box<Expr>,
+    #[span(hi)]
     pub alt: Box<Expr>,
 }
 
 #[ast_node]
 pub struct CallExpr {
+    pub span: Span,
     pub callee: ExprOrSuper,
     pub args: Vec<ExprOrSpread>,
 }
 #[ast_node]
 pub struct NewExpr {
+    pub span: Span,
     pub callee: Box<Expr>,
-    // #[code = "$( $( $args ),* )?"]
     pub args: Option<(Vec<ExprOrSpread>)>,
 }
 #[ast_node]
 pub struct SeqExpr {
+    /// TODO: Calculate
+    pub span: Span,
     pub exprs: Vec<(Box<Expr>)>,
 }
+
 #[ast_node]
 pub struct ArrowExpr {
+    pub span: Span,
     pub params: Vec<Pat>,
 
     pub body: BlockStmtOrExpr,
@@ -173,21 +181,26 @@ pub struct ArrowExpr {
 
 #[ast_node]
 pub struct YieldExpr {
+    pub span: Span,
     pub arg: Option<(Box<Expr>)>,
     pub delegate: bool,
 }
 #[ast_node]
 pub struct MetaPropExpr {
+    #[span(lo)]
     pub meta: Ident,
+    #[span(hi)]
     pub prop: Ident,
 }
 #[ast_node]
 pub struct AwaitExpr {
+    pub span: Span,
     pub arg: Box<Expr>,
 }
 
 #[ast_node]
 pub struct TplLit {
+    pub span: Span,
     pub tag: Option<(Box<Expr>)>,
 
     pub exprs: Vec<(Box<Expr>)>,
@@ -197,6 +210,7 @@ pub struct TplLit {
 
 #[ast_node]
 pub struct TplElement {
+    pub span: Span,
     pub tail: bool,
     pub cooked: bool,
     pub raw: String,
@@ -214,11 +228,20 @@ pub enum ExprOrSuper {
     Expr(Box<Expr>),
 }
 
-#[ast_node]
+#[derive(Fold, Clone, Debug, PartialEq)]
 pub struct ExprOrSpread {
     pub spread: Option<Span>,
     pub expr: Box<Expr>,
 }
+impl Spanned for ExprOrSpread {
+    fn span(&self) -> Span {
+        let expr = self.expr.span();
+        match self.spread {
+            Some(spread) => expr.with_lo(spread.lo()),
+            None => expr,
+        }
+    }
+}
 
 #[ast_node]
 pub enum BlockStmtOrExpr {

ecmascript/ast/src/lib.rs

@@ -12,15 +12,18 @@ pub use self::class::{Class, ClassMethod, ClassMethodKind};
 pub use self::decl::{ClassDecl, Decl, FnDecl, VarDecl, VarDeclKind, VarDeclarator};
 pub use self::expr::{ArrayLit, ArrowExpr, AssignExpr, AwaitExpr, BinExpr, BlockStmtOrExpr,
                      CallExpr, ClassExpr, CondExpr, Expr, ExprOrSpread, ExprOrSuper, FnExpr,
-                     MemberExpr, MetaPropExpr, NewExpr, ObjectLit, PatOrExpr, SeqExpr, TplElement,
-                     TplLit, UnaryExpr, UpdateExpr, YieldExpr};
+                     MemberExpr, MetaPropExpr, NewExpr, ObjectLit, ParenExpr, PatOrExpr, SeqExpr,
+                     ThisExpr, TplElement, TplLit, UnaryExpr, UpdateExpr, YieldExpr};
 pub use self::function::Function;
 pub use self::lit::{Bool, Lit, Null, Number, Regex, RegexFlags, Str};
 pub use self::module::{Module, ModuleItem};
-pub use self::module_decl::{ExportDefaultDecl, ExportSpecifier, ImportSpecifier, ModuleDecl};
+pub use self::module_decl::{ExportAll, ExportDefaultDecl, ExportSpecifier, ImportDecl,
+                            ImportDefault, ImportSpecific, ImportSpecifier, ImportStarAs,
+                            ModuleDecl, NamedExport};
 pub use self::operators::{AssignOp, BinaryOp, UnaryOp, UpdateOp};
-pub use self::pat::{ObjectPatProp, Pat};
-pub use self::prop::{Prop, PropName};
+pub use self::pat::{ArrayPat, AssignPat, AssignPatProp, KeyValuePatProp, ObjectPat, ObjectPatProp,
+                    Pat};
+pub use self::prop::{AssignProp, GetterProp, KeyValueProp, MethodProp, Prop, PropName, SetterProp};
 pub use self::stmt::{BlockStmt, BreakStmt, CatchClause, ContinueStmt, DebuggerStmt, DoWhileStmt,
                      EmptyStmt, ForInStmt, ForOfStmt, ForStmt, IfStmt, LabeledStmt, ReturnStmt,
                      Stmt, SwitchCase, SwitchStmt, ThrowStmt, TryStmt, VarDeclOrExpr,

ecmascript/ast/src/module_decl.rs

@@ -78,6 +78,7 @@ pub struct ImportSpecific {
 
 #[ast_node]
 pub struct ExportSpecifier {
+    pub span: Span,
     /// `foo` in `export { foo as bar }`
     pub orig: Ident,
     /// `Some(bar)` in `export { foo as bar }`

ecmascript/ast/src/pat.rs

@@ -10,7 +10,7 @@ pub enum Pat {
 
     Rest(Box<Pat>),
 
-    Object(Vec<ObjectPatProp>),
+    Object(ObjectPat),
 
     Assign(AssignPat),
 
@@ -24,6 +24,12 @@ pub struct ArrayPat {
     pub elems: Vec<(Option<Pat>)>,
 }
 
+#[ast_node]
+pub struct ObjectPat {
+    pub span: Span,
+    pub props: Vec<ObjectPatProp>,
+}
+
 #[ast_node]
 pub struct AssignPat {
     pub span: Span,
@@ -40,12 +46,15 @@ pub enum ObjectPatProp {
 /// `{key: value}`
 #[ast_node]
 pub struct KeyValuePatProp {
+    #[span(lo)]
     pub key: PropName,
+    #[span(hi)]
     pub value: Box<Pat>,
 }
 /// `{key}` or `{key = value}`
 #[ast_node]
 pub struct AssignPatProp {
+    pub span: Span,
     pub key: Ident,
 
     pub value: Option<(Box<Expr>)>,

ecmascript/ast/src/prop.rs

@@ -18,18 +18,18 @@ pub enum Prop {
 
 #[ast_node]
 pub struct KeyValueProp {
-    // #[span(lo)]
+    #[span(lo)]
     pub key: PropName,
 
-    // #[span(hi)]
+    #[span(hi)]
     pub value: Box<Expr>,
 }
 
 #[ast_node]
 pub struct AssignProp {
-    // #[span(lo)]
+    #[span(lo)]
     key: Ident,
-    // #[span(hi)]
+    #[span(hi)]
     value: Box<Expr>,
 }
 #[ast_node]
@@ -47,9 +47,9 @@ pub struct SetterProp {
 }
 #[ast_node]
 pub struct MethodProp {
-    // #[span(lo)]
+    #[span(lo)]
     key: PropName,
-    // #[span(hi)]
+    #[span(hi)]
     function: Function,
 }
 

macros/ast_node/Cargo.toml

@@ -11,6 +11,7 @@ swc_macros_common = { path = "../common" }
 pmutil = "0.1"
 proc-macro2 = { version = "0.2", features = ["nightly"] }
 quote = "0.4"
+darling = "0.3"
 
 [dependencies.syn]
 version = "0.12"

macros/ast_node/src/lib.rs

@@ -1,5 +1,7 @@
 #![feature(box_syntax, proc_macro)]
 
+#[macro_use]
+extern crate darling;
 #[macro_use]
 extern crate pmutil;
 extern crate proc_macro;

macros/ast_node/src/spanned.rs

@@ -1,5 +1,22 @@
+use darling::FromField;
 use swc_macros_common::prelude::*;
 
+#[derive(Debug, FromField)]
+#[darling(attributes(span))]
+struct MyField {
+    /// Name of the field.
+    pub ident: Option<Ident>,
+    /// Type of the field.
+    pub ty: Type,
+
+    /// `#[span(lo)]`
+    #[darling(default)]
+    pub lo: bool,
+    /// `#[span(hi)]`
+    #[darling(default)]
+    pub hi: bool,
+}
+
 pub fn derive(input: DeriveInput) -> ItemImpl {
     let arms = Binder::new_from(&input)
         .variants()
@@ -53,6 +70,15 @@ pub fn derive(input: DeriveInput) -> ItemImpl {
 }
 
 fn make_body_for_variant(v: &VariantBinder, bindings: Vec<BindedField>) -> Box<Expr> {
+    /// `swc_common::Spanned::span(#field)`
+    fn simple_field(field: &ToTokens) -> Box<Expr> {
+        box Quote::new(Span::def_site())
+            .quote_with(smart_quote!(Vars { field }, {
+                swc_common::Spanned::span(field)
+            }))
+            .parse()
+    }
+
     if bindings.len() == 0 {
         panic!("#[derive(Spanned)] requires a field to get span from")
     }
@@ -61,27 +87,35 @@ fn make_body_for_variant(v: &VariantBinder, bindings: Vec<BindedField>) -> Box<E
         match *v.data() {
             Fields::Unnamed(..) => {
                 // Call self.0.span()
-                return box Quote::new(Span::def_site())
-                    .quote_with(smart_quote!(
-                        Vars {
-                            field: &bindings[0],
-                        },
-                        { swc_common::Spanned::span(field) }
-                    ))
-                    .parse();
+                return simple_field(&bindings[0]);
             }
             _ => {}
         }
     }
 
-    // TODO: Handle #[span] attribute.
+    //  Handle #[span] attribute.
+    if let Some(f) = bindings
+        .iter()
+        .find(|b| has_empty_span_attr(&b.field().attrs))
+    {
+        //TODO: Verify that there's no more #[span]
+        return simple_field(f);
+    }
 
+    // If all fields do not have `#[span(..)]`, check for field named `span`.
+    let has_any_span_attr = bindings
+        .iter()
+        .map(|b| {
+            b.field()
+                .attrs
+                .iter()
+                .any(|attr| is_attr_name(attr, "span"))
+        })
+        .any(|b| b);
+    if !has_any_span_attr {
         let span_field = bindings
             .iter()
-        .find(|b| {
-            let s = b.field().ident.as_ref().map(|ident| ident.as_ref());
-            Some("span") == s
-        })
+            .find(|b| Some("span") == b.field().ident.as_ref().map(|ident| ident.as_ref()))
             .unwrap_or_else(|| {
                 panic!(
                     "#[derive(Spanned)]: cannot determine span field to use for {}",
@@ -89,7 +123,39 @@ fn make_body_for_variant(v: &VariantBinder, bindings: Vec<BindedField>) -> Box<E
                 )
             });
 
+        return simple_field(span_field);
+    }
+
+    let fields: Vec<_> = bindings
+        .iter()
+        .map(|b| (b, MyField::from_field(b.field()).unwrap()))
+        .collect();
+
+    // TODO: Only one field should be `#[span(lo)]`.
+    let lo = fields.iter().find(|&&(_, ref f)| f.lo);
+    let hi = fields.iter().find(|&&(_, ref f)| f.hi);
+
+    match (lo, hi) {
+        (Some(&(ref lo_field, _)), Some(&(ref hi_field, _))) => {
+            // Create a new span from lo_field.lo(), hi_field.hi()
             box Quote::new(Span::def_site())
-        .quote_with(smart_quote!(Vars { span_field }, { span_field }))
+                .quote_with(smart_quote!(Vars { lo_field, hi_field }, {
+                    swc_common::Spanned::span(lo_field)
+                        .with_hi(swc_common::Spanned::span(hi_field).hi())
+                }))
                 .parse()
+        }
+        _ => panic!("#[derive(Spanned)]: #[span(lo)] and #[span(hi)] is required"),
+    }
+}
+
+/// Search for `#[span]`
+fn has_empty_span_attr(attrs: &[Attribute]) -> bool {
+    attrs.iter().any(|attr| {
+        if !is_attr_name(attr, "span") {
+            return false;
+        }
+
+        attr.tts.is_empty()
+    })
 }

macros/ast_node/tests/attr_interop.rs

@@ -0,0 +1,24 @@
+//! Test that `#[span]` and `#[fold]` can be used at same time.
+#![feature(proc_macro)]
+
+extern crate swc_common;
+extern crate swc_macros;
+use swc_common::{Fold, Span, Spanned};
+use swc_macros::ast_node;
+
+#[ast_node]
+// See https://github.com/rust-lang/rust/issues/44925
+pub struct Class {
+    #[span]
+    pub has_span: HasSpan,
+    #[fold(ignore)]
+    pub s: String,
+}
+
+#[ast_node]
+pub struct Tuple(#[span] HasSpan, #[fold(ignore)] usize, usize);
+
+#[derive(Debug, Clone, PartialEq, Fold, Spanned)]
+pub struct HasSpan {
+    pub span: Span,
+}

macros/ast_node/tests/attribute.rs

@@ -1,15 +0,0 @@
-#![feature(specialization, proc_macro)]
-
-extern crate swc_common;
-extern crate swc_macros;
-use swc_macros::ast_node;
-
-#[ast_node]
-// See https://github.com/rust-lang/rust/issues/44925
-pub struct Class {
-    #[fold(ignore)]
-    pub s: String,
-}
-
-#[ast_node]
-pub struct Tuple(usize, usize);

macros/ast_node/tests/empty.rs

@@ -1,12 +1,12 @@
-#![feature(specialization, proc_macro)]
+#![feature(proc_macro)]
 
+extern crate ast_node;
 extern crate swc_common;
-extern crate swc_macros;
-use swc_macros::ast_node;
+use ast_node::*;
 
-#[ast_node]
+#[derive(Debug, Fold)]
 pub struct Struct {}
 
-#[ast_node]
+#[derive(Debug, FromVariant, Fold)]
 pub enum Enum {
 }

macros/ast_node/tests/fold_bound.rs

@@ -1,30 +1,29 @@
-//! Ensures that #[derive(AstNode)] works with generic types.
+//! Ensures that #[derive(Fold)] works with generic types.
 
 #![feature(specialization, proc_macro)]
 
 extern crate swc_common;
 extern crate swc_macros;
 use std::fmt::Debug;
-use swc_common::AstNode;
-use swc_macros::ast_node;
+use swc_common::{AstNode, Fold};
 
 pub trait Ast: Copy + Eq + Debug {
     type CustomExpr: AstNode;
 }
 
-#[ast_node]
+#[derive(Fold)]
 pub struct Stmt<A: Ast> {
     #[fold(bound)]
     pub expr: Expr<A>,
 }
 
-#[ast_node]
+#[derive(Fold)]
 pub struct Expr<A: Ast> {
     #[fold(bound)]
     pub node: ExprKind<A>,
 }
 
-#[ast_node]
+#[derive(Fold)]
 pub enum ExprKind<A: Ast> {
     Custom(#[fold(bound)] A::CustomExpr),
     /// Recursive

macros/ast_node/tests/fold_simple.rs

@@ -2,15 +2,14 @@
 
 extern crate swc_common;
 extern crate swc_macros;
-use swc_common::{FoldWith, Folder};
-use swc_macros::ast_node;
+use swc_common::{Fold, FoldWith};
 
-pub trait AssertFolder<T>: Folder<T> {}
+pub trait AssertFolder<T>: Fold<T> {}
 
 // check for trait bound
 
 pub struct LitFolder;
-impl Folder<Lit> for LitFolder {
+impl Fold<Lit> for LitFolder {
     fn fold(&mut self, _: Lit) -> Lit {
         Lit::A
     }
@@ -18,7 +17,7 @@ impl Folder<Lit> for LitFolder {
 impl AssertFolder<Expr> for LitFolder {}
 impl AssertFolder<ExprKind> for LitFolder {}
 
-#[ast_node]
+#[derive(Debug, Fold, PartialEq, Eq)]
 pub struct Expr {
     pub node: ExprKind,
     /// This field should be skipped.
@@ -40,7 +39,7 @@ impl<F> FoldWith<F> for PanicOnFold {
     }
 }
 
-#[ast_node]
+#[derive(Debug, Fold, PartialEq, Eq)]
 pub enum ExprKind {
     RecursiveBoud(Box<Expr>),
     Rec2(Vec<Option<Box<Expr>>>),
@@ -48,7 +47,7 @@ pub enum ExprKind {
     Lit(Lit),
 }
 
-#[ast_node]
+#[derive(Debug, Fold, PartialEq, Eq)]
 pub enum Lit {
     A,
     B,

macros/ast_node/tests/spanned_attr.rs

@@ -0,0 +1,22 @@
+#![feature(proc_macro)]
+
+extern crate swc_common;
+use swc_common::{BytePos, Span, Spanned};
+
+#[test]
+fn lo_hi() {
+    #[derive(Spanned)]
+    struct LoHi {
+        #[span(lo)]
+        pub lo: BytePos,
+        #[span(hi)]
+        pub hi: BytePos,
+    }
+
+    let lo = BytePos(0);
+    let hi = BytePos(5);
+    assert_eq!(
+        LoHi { lo, hi }.span(),
+        Span::new(lo, hi, Default::default())
+    );
+}