syntax: Remove `SyntaxExtension::MultiDecorator` and `MultiItemDecorator`

9 files changed, 1 insertions, 410 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index ffc32127924..9979f5d0a0e 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -137,29 +137,6 @@ impl Annotatable {
     }
 }
 
-// A more flexible ItemDecorator.
-pub trait MultiItemDecorator {
-    fn expand(&self,
-              ecx: &mut ExtCtxt<'_>,
-              sp: Span,
-              meta_item: &ast::MetaItem,
-              item: &Annotatable,
-              push: &mut dyn FnMut(Annotatable));
-}
-
-impl<F> MultiItemDecorator for F
-    where F : Fn(&mut ExtCtxt<'_>, Span, &ast::MetaItem, &Annotatable, &mut dyn FnMut(Annotatable))
-{
-    fn expand(&self,
-              ecx: &mut ExtCtxt<'_>,
-              sp: Span,
-              meta_item: &ast::MetaItem,
-              item: &Annotatable,
-              push: &mut dyn FnMut(Annotatable)) {
-        (*self)(ecx, sp, meta_item, item, push)
-    }
-}
-
 // `meta_item` is the annotation, and `item` is the item being modified.
 // FIXME Decorators should follow the same pattern too.
 pub trait MultiItemModifier {
@@ -581,14 +558,6 @@ pub enum SyntaxExtension {
     /// A trivial "extension" that does nothing, only keeps the attribute and marks it as known.
     NonMacroAttr { mark_used: bool },
 
-    /// A syntax extension that is attached to an item and creates new items
-    /// based upon it.
-    ///
-    /// `#[derive(...)]` is a `MultiItemDecorator`.
-    ///
-    /// Prefer ProcMacro or MultiModifier since they are more flexible.
-    MultiDecorator(Box<dyn MultiItemDecorator + sync::Sync + sync::Send>),
-
     /// A syntax extension that is attached to an item and modifies it
     /// in-place. Also allows decoration, i.e., creating new items.
     MultiModifier(Box<dyn MultiItemModifier + sync::Sync + sync::Send>),
@@ -658,7 +627,6 @@ impl SyntaxExtension {
             SyntaxExtension::ProcMacro { .. } =>
                 MacroKind::Bang,
             SyntaxExtension::NonMacroAttr { .. } |
-            SyntaxExtension::MultiDecorator(..) |
             SyntaxExtension::MultiModifier(..) |
             SyntaxExtension::AttrProcMacro(..) =>
                 MacroKind::Attr,
@@ -688,7 +656,6 @@ impl SyntaxExtension {
             SyntaxExtension::ProcMacroDerive(.., edition) => edition,
             // Unstable legacy stuff
             SyntaxExtension::NonMacroAttr { .. } |
-            SyntaxExtension::MultiDecorator(..) |
             SyntaxExtension::MultiModifier(..) |
             SyntaxExtension::BuiltinDerive(..) => default_edition,
         }
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 008bcaab889..715303db173 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -575,14 +575,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 let item = mac.expand(self.cx, attr.span, &meta, item);
                 Some(invoc.fragment_kind.expect_from_annotatables(item))
             }
-            MultiDecorator(ref mac) => {
-                let mut items = Vec::new();
-                let meta = attr.parse_meta(self.cx.parse_sess)
-                               .expect("derive meta should already have been parsed");
-                mac.expand(self.cx, attr.span, &meta, &item, &mut |item| items.push(item));
-                items.push(item);
-                Some(invoc.fragment_kind.expect_from_annotatables(items))
-            }
             AttrProcMacro(ref mac, ..) => {
                 self.gate_proc_macro_attr_item(attr.span, &item);
                 let item_tok = TokenTree::token(token::Interpolated(Lrc::new(match item {
@@ -791,8 +783,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 }
             }
 
-            MultiDecorator(..) | MultiModifier(..) |
-            AttrProcMacro(..) | SyntaxExtension::NonMacroAttr { .. } => {
+            MultiModifier(..) | AttrProcMacro(..) | SyntaxExtension::NonMacroAttr { .. } => {
                 self.cx.span_err(path.span,
                                  &format!("`{}` can only be used in attributes", path));
                 self.cx.trace_macros_diag();
diff --git a/src/test/run-pass-fulldeps/auxiliary/custom-derive-partial-eq.rs b/src/test/run-pass-fulldeps/auxiliary/custom-derive-partial-eq.rs
deleted file mode 100644
index 4d6ff47a3ee..00000000000
--- a/src/test/run-pass-fulldeps/auxiliary/custom-derive-partial-eq.rs
+++ /dev/null
@@ -1,71 +0,0 @@
-// force-host
-
-#![feature(plugin_registrar, rustc_private)]
-
-extern crate syntax;
-extern crate syntax_ext;
-extern crate rustc_plugin;
-
-use syntax_ext::deriving;
-use deriving::generic::*;
-use deriving::generic::ty::*;
-
-use rustc_plugin::Registry;
-use syntax::ast::*;
-use syntax::source_map::Span;
-use syntax::ext::base::*;
-use syntax::ext::build::AstBuilder;
-use syntax::symbol::Symbol;
-use syntax::ptr::P;
-
-#[plugin_registrar]
-pub fn plugin_registrar(reg: &mut Registry) {
-    reg.register_syntax_extension(Symbol::intern("derive_CustomPartialEq"),
-                                  MultiDecorator(Box::new(expand_deriving_partial_eq)));
-}
-
-fn expand_deriving_partial_eq(cx: &mut ExtCtxt, span: Span, mitem: &MetaItem, item: &Annotatable,
-                              push: &mut FnMut(Annotatable)) {
-    // structures are equal if all fields are equal, and non equal, if
-    // any fields are not equal or if the enum variants are different
-    fn cs_eq(cx: &mut ExtCtxt, span: Span, substr: &Substructure) -> P<Expr> {
-        cs_fold(true,
-                |cx, span, subexpr, self_f, other_fs| {
-                    let other_f = (other_fs.len(), other_fs.get(0)).1.unwrap();
-                    let eq = cx.expr_binary(span, BinOpKind::Eq, self_f, other_f.clone());
-                    cx.expr_binary(span, BinOpKind::And, subexpr, eq)
-                },
-                cx.expr_bool(span, true),
-                Box::new(|cx, span, _, _| cx.expr_bool(span, false)),
-                cx,
-                span,
-                substr)
-    }
-
-    let inline = cx.meta_word(span, Symbol::intern("inline"));
-    let attrs = vec![cx.attribute(span, inline)];
-    let methods = vec![MethodDef {
-        name: "eq",
-        generics: LifetimeBounds::empty(),
-        explicit_self: borrowed_explicit_self(),
-        args: vec![(borrowed_self(), "other")],
-        ret_ty: Literal(deriving::generic::ty::Path::new_local("bool")),
-        attributes: attrs,
-        is_unsafe: false,
-        unify_fieldless_variants: true,
-        combine_substructure: combine_substructure(Box::new(cs_eq)),
-    }];
-
-    let trait_def = TraitDef {
-        span: span,
-        attributes: Vec::new(),
-        path: deriving::generic::ty::Path::new(vec!["cmp", "PartialEq"]),
-        additional_bounds: Vec::new(),
-        generics: LifetimeBounds::empty(),
-        is_unsafe: false,
-        supports_unions: false,
-        methods: methods,
-        associated_types: Vec::new(),
-    };
-    trait_def.expand(cx, mitem, item, push)
-}
diff --git a/src/test/run-pass-fulldeps/auxiliary/custom-derive-plugin-attr.rs b/src/test/run-pass-fulldeps/auxiliary/custom-derive-plugin-attr.rs
deleted file mode 100644
index c6b33fbc75e..00000000000
--- a/src/test/run-pass-fulldeps/auxiliary/custom-derive-plugin-attr.rs
+++ /dev/null
@@ -1,84 +0,0 @@
-// force-host
-
-#![feature(plugin_registrar)]
-#![feature(box_syntax)]
-#![feature(rustc_private)]
-
-extern crate syntax;
-extern crate syntax_ext;
-extern crate syntax_pos;
-extern crate rustc;
-extern crate rustc_plugin;
-
-use syntax::ast;
-use syntax::attr;
-use syntax::ext::base::{MultiDecorator, ExtCtxt, Annotatable};
-use syntax::ext::build::AstBuilder;
-use syntax::symbol::{Symbol, sym};
-use syntax::ptr::P;
-use syntax_ext::deriving::generic::{TraitDef, MethodDef, combine_substructure};
-use syntax_ext::deriving::generic::{Substructure, Struct, EnumMatching};
-use syntax_ext::deriving::generic::ty::{Literal, LifetimeBounds, Path, borrowed_explicit_self};
-use syntax_pos::Span;
-use rustc_plugin::Registry;
-
-#[plugin_registrar]
-pub fn plugin_registrar(reg: &mut Registry) {
-    reg.register_syntax_extension(
-        Symbol::intern("rustc_derive_TotalSum"),
-        MultiDecorator(box expand));
-}
-
-fn expand(cx: &mut ExtCtxt,
-          span: Span,
-          mitem: &ast::MetaItem,
-          item: &Annotatable,
-          push: &mut FnMut(Annotatable)) {
-    let trait_def = TraitDef {
-        span: span,
-        attributes: vec![],
-        path: Path::new_local("TotalSum"),
-        additional_bounds: vec![],
-        generics: LifetimeBounds::empty(),
-        associated_types: vec![],
-        is_unsafe: false,
-        supports_unions: false,
-        methods: vec![
-            MethodDef {
-                name: "total_sum",
-                generics: LifetimeBounds::empty(),
-                explicit_self: borrowed_explicit_self(),
-                args: vec![],
-                ret_ty: Literal(Path::new_local("isize")),
-                attributes: vec![],
-                is_unsafe: false,
-                unify_fieldless_variants: true,
-                combine_substructure: combine_substructure(Box::new(totalsum_substructure)),
-            },
-        ],
-    };
-
-    trait_def.expand(cx, mitem, item, push)
-}
-
-// Mostly copied from syntax::ext::deriving::hash
-/// Defines how the implementation for `trace()` is to be generated
-fn totalsum_substructure(cx: &mut ExtCtxt, trait_span: Span,
-                         substr: &Substructure) -> P<ast::Expr> {
-    let fields = match *substr.fields {
-        Struct(_, ref fs) | EnumMatching(.., ref fs) => fs,
-        _ => cx.span_bug(trait_span, "impossible substructure")
-    };
-
-    fields.iter().fold(cx.expr_isize(trait_span, 0), |acc, ref item| {
-        if attr::contains_name(&item.attrs, sym::ignore) {
-            acc
-        } else {
-            cx.expr_binary(item.span, ast::BinOpKind::Add, acc,
-                           cx.expr_method_call(item.span,
-                                               item.self_.clone(),
-                                               substr.method_ident,
-                                               Vec::new()))
-        }
-    })
-}
diff --git a/src/test/run-pass-fulldeps/auxiliary/custom-derive-plugin.rs b/src/test/run-pass-fulldeps/auxiliary/custom-derive-plugin.rs
deleted file mode 100644
index 874a0ec7c13..00000000000
--- a/src/test/run-pass-fulldeps/auxiliary/custom-derive-plugin.rs
+++ /dev/null
@@ -1,76 +0,0 @@
-// force-host
-
-#![feature(plugin_registrar)]
-#![feature(box_syntax)]
-#![feature(rustc_private)]
-
-extern crate syntax;
-extern crate syntax_ext;
-extern crate syntax_pos;
-extern crate rustc;
-extern crate rustc_plugin;
-
-use syntax::ast;
-use syntax::ext::base::{MultiDecorator, ExtCtxt, Annotatable};
-use syntax::ext::build::AstBuilder;
-use syntax::symbol::Symbol;
-use syntax_ext::deriving::generic::{cs_fold, TraitDef, MethodDef, combine_substructure};
-use syntax_ext::deriving::generic::ty::{Literal, LifetimeBounds, Path, borrowed_explicit_self};
-use syntax_pos::Span;
-use rustc_plugin::Registry;
-
-#[plugin_registrar]
-pub fn plugin_registrar(reg: &mut Registry) {
-    reg.register_syntax_extension(
-        Symbol::intern("derive_TotalSum"),
-        MultiDecorator(box expand));
-
-    reg.register_syntax_extension(
-        Symbol::intern("derive_Nothing"),
-        MultiDecorator(box noop));
-}
-
-fn noop(_: &mut ExtCtxt, _: Span, _: &ast::MetaItem, _: &Annotatable, _: &mut FnMut(Annotatable)) {}
-
-fn expand(cx: &mut ExtCtxt,
-          span: Span,
-          mitem: &ast::MetaItem,
-          item: &Annotatable,
-          push: &mut FnMut(Annotatable)) {
-    let trait_def = TraitDef {
-        span: span,
-        attributes: vec![],
-        path: Path::new_local("TotalSum"),
-        additional_bounds: vec![],
-        generics: LifetimeBounds::empty(),
-        associated_types: vec![],
-        is_unsafe: false,
-        supports_unions: false,
-        methods: vec![
-            MethodDef {
-                name: "total_sum",
-                generics: LifetimeBounds::empty(),
-                explicit_self: borrowed_explicit_self(),
-                args: vec![],
-                ret_ty: Literal(Path::new_local("isize")),
-                attributes: vec![],
-                is_unsafe: false,
-                unify_fieldless_variants: true,
-                combine_substructure: combine_substructure(box |cx, span, substr| {
-                    let zero = cx.expr_isize(span, 0);
-                    cs_fold(false,
-                            |cx, span, subexpr, field, _| {
-                                cx.expr_binary(span, ast::BinOpKind::Add, subexpr,
-                                    cx.expr_method_call(span, field,
-                                        ast::Ident::from_str("total_sum"), vec![]))
-                            },
-                            zero,
-                            box |cx, span, _, _| { cx.span_bug(span, "wtf??"); },
-                            cx, span, substr)
-                }),
-            },
-        ],
-    };
-
-    trait_def.expand(cx, mitem, item, push)
-}
diff --git a/src/test/run-pass-fulldeps/custom-derive-partial-eq.rs b/src/test/run-pass-fulldeps/custom-derive-partial-eq.rs
deleted file mode 100644
index ac8fff4f6bf..00000000000
--- a/src/test/run-pass-fulldeps/custom-derive-partial-eq.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-// aux-build:custom-derive-partial-eq.rs
-// ignore-stage1
-#![feature(plugin)]
-#![plugin(custom_derive_partial_eq)]
-#![allow(unused)]
-
-#[derive_CustomPartialEq] // Check that this is not a stability error.
-enum E { V1, V2 }
-
-fn main() {}
diff --git a/src/test/run-pass-fulldeps/derive-totalsum-attr.rs b/src/test/run-pass-fulldeps/derive-totalsum-attr.rs
deleted file mode 100644
index 38eaa71dd6a..00000000000
--- a/src/test/run-pass-fulldeps/derive-totalsum-attr.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-// aux-build:custom-derive-plugin-attr.rs
-// ignore-stage1
-
-#![feature(plugin, rustc_attrs)]
-#![plugin(custom_derive_plugin_attr)]
-
-trait TotalSum {
-    fn total_sum(&self) -> isize;
-}
-
-impl TotalSum for isize {
-    fn total_sum(&self) -> isize {
-        *self
-    }
-}
-
-struct Seven;
-
-impl TotalSum for Seven {
-    fn total_sum(&self) -> isize {
-        7
-    }
-}
-
-#[rustc_derive_TotalSum]
-struct Foo {
-    seven: Seven,
-    bar: Bar,
-    baz: isize,
-    #[ignore]
-    nan: NaN,
-}
-
-#[rustc_derive_TotalSum]
-struct Bar {
-    quux: isize,
-    bleh: isize,
-    #[ignore]
-    nan: NaN2
-}
-
-struct NaN;
-
-impl TotalSum for NaN {
-    fn total_sum(&self) -> isize {
-        panic!();
-    }
-}
-
-struct NaN2;
-
-pub fn main() {
-    let v = Foo {
-        seven: Seven,
-        bar: Bar {
-            quux: 9,
-            bleh: 3,
-            nan: NaN2
-        },
-        baz: 80,
-        nan: NaN
-    };
-    assert_eq!(v.total_sum(), 99);
-}
diff --git a/src/test/run-pass-fulldeps/derive-totalsum.rs b/src/test/run-pass-fulldeps/derive-totalsum.rs
deleted file mode 100644
index 2b0bb51d90a..00000000000
--- a/src/test/run-pass-fulldeps/derive-totalsum.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-// aux-build:custom-derive-plugin.rs
-// ignore-stage1
-
-#![feature(plugin)]
-#![plugin(custom_derive_plugin)]
-
-trait TotalSum {
-    fn total_sum(&self) -> isize;
-}
-
-impl TotalSum for isize {
-    fn total_sum(&self) -> isize {
-        *self
-    }
-}
-
-struct Seven;
-
-impl TotalSum for Seven {
-    fn total_sum(&self) -> isize {
-        7
-    }
-}
-
-#[derive_TotalSum]
-struct Foo {
-    seven: Seven,
-    bar: Bar,
-    baz: isize,
-}
-
-#[derive_TotalSum]
-struct Bar {
-    quux: isize,
-    bleh: isize,
-}
-
-
-pub fn main() {
-    let v = Foo {
-        seven: Seven,
-        bar: Bar {
-            quux: 9,
-            bleh: 3,
-        },
-        baz: 80,
-    };
-    assert_eq!(v.total_sum(), 99);
-}
diff --git a/src/test/run-pass-fulldeps/issue-40663.rs b/src/test/run-pass-fulldeps/issue-40663.rs
deleted file mode 100644
index 133f6302bde..00000000000
--- a/src/test/run-pass-fulldeps/issue-40663.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-#![allow(dead_code)]
-// aux-build:custom-derive-plugin.rs
-// ignore-stage1
-
-#![feature(plugin)]
-#![plugin(custom_derive_plugin)]
-
-#[derive_Nothing]
-#[derive_Nothing]
-#[derive_Nothing]
-struct S;
-
-fn main() {}