Accept `derive` instead of `deriving`

[breaking-change]

`deriving is still accepted, but gives a deprecation warning

4 files changed, 36 insertions, 24 deletions

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 692ecf75091..82aa40cb0ad 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -551,7 +551,7 @@ impl LintPass for BoxPointers {
 declare_lint! {
     RAW_POINTER_DERIVING,
     Warn,
-    "uses of #[deriving] with raw pointers are rarely correct"
+    "uses of #[derive] with raw pointers are rarely correct"
 }
 
 struct RawPtrDerivingVisitor<'a, 'tcx: 'a> {
@@ -560,7 +560,7 @@ struct RawPtrDerivingVisitor<'a, 'tcx: 'a> {
 
 impl<'a, 'tcx, 'v> Visitor<'v> for RawPtrDerivingVisitor<'a, 'tcx> {
     fn visit_ty(&mut self, ty: &ast::Ty) {
-        static MSG: &'static str = "use of `#[deriving]` with a raw pointer";
+        static MSG: &'static str = "use of `#[derive]` with a raw pointer";
         if let ast::TyPtr(..) = ty.node {
             self.cx.span_lint(RAW_POINTER_DERIVING, ty.span, MSG);
         }
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 5134897893f..efb4867a016 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -390,6 +390,8 @@ fn initial_syntax_expander_table(ecfg: &expand::ExpansionConfig) -> SyntaxEnv {
     syntax_expanders.insert(intern("log_syntax"),
                             builtin_normal_expander(
                                     ext::log_syntax::expand_syntax_ext));
+    syntax_expanders.insert(intern("derive"),
+                            Decorator(box ext::deriving::expand_meta_derive));
     syntax_expanders.insert(intern("deriving"),
                             Decorator(box ext::deriving::expand_meta_deriving));
 
diff --git a/src/libsyntax/ext/deriving/generic/mod.rs b/src/libsyntax/ext/deriving/generic/mod.rs
index 9149c20ce1b..acfb020fab6 100644
--- a/src/libsyntax/ext/deriving/generic/mod.rs
+++ b/src/libsyntax/ext/deriving/generic/mod.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 //! Some code that abstracts away much of the boilerplate of writing
-//! `deriving` instances for traits. Among other things it manages getting
+//! `derive` instances for traits. Among other things it manages getting
 //! access to the fields of the 4 different sorts of structs and enum
 //! variants, as well as creating the method and impl ast instances.
 //!
@@ -26,7 +26,7 @@
 //!   moment. (`TraitDef.additional_bounds`)
 //!
 //! Unsupported: FIXME #6257: calling methods on reference fields,
-//! e.g. deriving Eq/Ord/Clone don't work on `struct A(&int)`,
+//! e.g. derive Eq/Ord/Clone don't work on `struct A(&int)`,
 //! because of how the auto-dereferencing happens.
 //!
 //! The most important thing for implementers is the `Substructure` and
@@ -209,7 +209,7 @@ use self::ty::{LifetimeBounds, Path, Ptr, PtrTy, Self, Ty};
 pub mod ty;
 
 pub struct TraitDef<'a> {
-    /// The span for the current #[deriving(Foo)] header.
+    /// The span for the current #[derive(Foo)] header.
     pub span: Span,
 
     pub attributes: Vec<ast::Attribute>,
@@ -354,7 +354,7 @@ impl<'a> TraitDef<'a> {
                                      generics)
             }
             _ => {
-                cx.span_err(mitem.span, "`deriving` may only be applied to structs and enums");
+                cx.span_err(mitem.span, "`derive` may only be applied to structs and enums");
                 return;
             }
         };
@@ -718,7 +718,7 @@ impl<'a> MethodDef<'a> {
     }
 
     /// ```
-    /// #[deriving(PartialEq)]
+    /// #[derive(PartialEq)]
     /// struct A { x: int, y: int }
     ///
     /// // equivalent to:
@@ -782,7 +782,7 @@ impl<'a> MethodDef<'a> {
         } else {
             cx.span_bug(trait_.span,
                         "no self arguments to non-static method in generic \
-                         `deriving`")
+                         `derive`")
         };
 
         // body of the inner most destructuring match
@@ -822,7 +822,7 @@ impl<'a> MethodDef<'a> {
     }
 
     /// ```
-    /// #[deriving(PartialEq)]
+    /// #[derive(PartialEq)]
     /// enum A {
     ///     A1,
     ///     A2(int)
@@ -1185,7 +1185,7 @@ impl<'a> TraitDef<'a> {
                      cx: &mut ExtCtxt,
                      mut to_set: Span) -> Span {
         let trait_name = match self.path.path.last() {
-            None => cx.span_bug(self.span, "trait with empty path in generic `deriving`"),
+            None => cx.span_bug(self.span, "trait with empty path in generic `derive`"),
             Some(name) => *name
         };
         to_set.expn_id = cx.codemap().record_expansion(codemap::ExpnInfo {
@@ -1215,7 +1215,7 @@ impl<'a> TraitDef<'a> {
         match (just_spans.is_empty(), named_idents.is_empty()) {
             (false, false) => cx.span_bug(self.span,
                                           "a struct with named and unnamed \
-                                          fields in generic `deriving`"),
+                                          fields in generic `derive`"),
             // named fields
             (_, false) => Named(named_idents),
             // tuple structs (includes empty structs)
@@ -1263,7 +1263,7 @@ impl<'a> TraitDef<'a> {
                     None
                 }
                 _ => {
-                    cx.span_bug(sp, "a struct with named and unnamed fields in `deriving`");
+                    cx.span_bug(sp, "a struct with named and unnamed fields in `derive`");
                 }
             };
             let ident = cx.ident_of(format!("{}_{}", prefix, i)[]);
@@ -1371,7 +1371,7 @@ pub fn cs_fold<F>(use_foldl: bool,
             enum_nonmatch_f(cx, trait_span, (all_args[], tuple),
                             substructure.nonself_args),
         StaticEnum(..) | StaticStruct(..) => {
-            cx.span_bug(trait_span, "static function in `deriving`")
+            cx.span_bug(trait_span, "static function in `derive`")
         }
     }
 }
@@ -1411,7 +1411,7 @@ pub fn cs_same_method<F>(f: F,
             enum_nonmatch_f(cx, trait_span, (all_self_args[], tuple),
                             substructure.nonself_args),
         StaticEnum(..) | StaticStruct(..) => {
-            cx.span_bug(trait_span, "static function in `deriving`")
+            cx.span_bug(trait_span, "static function in `derive`")
         }
     }
 }
diff --git a/src/libsyntax/ext/deriving/mod.rs b/src/libsyntax/ext/deriving/mod.rs
index 75f763b5c38..57d66f0e355 100644
--- a/src/libsyntax/ext/deriving/mod.rs
+++ b/src/libsyntax/ext/deriving/mod.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-//! The compiler code necessary to implement the `#[deriving]` extensions.
+//! The compiler code necessary to implement the `#[derive]` extensions.
 //!
 //! FIXME (#2810): hygiene. Search for "__" strings (in other files too). We also assume "extra" is
 //! the standard library, and "std" is the core library.
@@ -45,16 +45,26 @@ pub fn expand_meta_deriving(cx: &mut ExtCtxt,
                             _span: Span,
                             mitem: &MetaItem,
                             item: &Item,
-                            mut push: Box<FnMut(P<Item>)>) {
+                            push: Box<FnMut(P<Item>)>) {
+    cx.span_warn(mitem.span, "`deriving` is deprecated; use `derive`");
+
+    expand_meta_derive(cx, _span, mitem, item, push)
+}
+
+pub fn expand_meta_derive(cx: &mut ExtCtxt,
+                          _span: Span,
+                          mitem: &MetaItem,
+                          item: &Item,
+                          mut push: Box<FnMut(P<Item>)>) {
     match mitem.node {
         MetaNameValue(_, ref l) => {
-            cx.span_err(l.span, "unexpected value in `deriving`");
+            cx.span_err(l.span, "unexpected value in `derive`");
         }
         MetaWord(_) => {
-            cx.span_warn(mitem.span, "empty trait list in `deriving`");
+            cx.span_warn(mitem.span, "empty trait list in `derive`");
         }
         MetaList(_, ref titems) if titems.len() == 0 => {
-            cx.span_warn(mitem.span, "empty trait list in `deriving`");
+            cx.span_warn(mitem.span, "empty trait list in `derive`");
         }
         MetaList(_, ref titems) => {
             for titem in titems.iter().rev() {
@@ -78,15 +88,15 @@ pub fn expand_meta_deriving(cx: &mut ExtCtxt,
                             }
                             "Encodable" => {
                                 cx.span_warn(titem.span,
-                                             "deriving(Encodable) is deprecated \
-                                              in favor of deriving(RustcEncodable)");
+                                             "derive(Encodable) is deprecated \
+                                              in favor of derive(RustcEncodable)");
 
                                 expand!(encodable::expand_deriving_encodable)
                             }
                             "Decodable" => {
                                 cx.span_warn(titem.span,
-                                             "deriving(Decodable) is deprecated \
-                                              in favor of deriving(RustcDecodable)");
+                                             "derive(Decodable) is deprecated \
+                                              in favor of derive(RustcDecodable)");
 
                                 expand!(decodable::expand_deriving_decodable)
                             }
@@ -111,7 +121,7 @@ pub fn expand_meta_deriving(cx: &mut ExtCtxt,
 
                             ref tname => {
                                 cx.span_err(titem.span,
-                                            format!("unknown `deriving` \
+                                            format!("unknown `derive` \
                                                      trait: `{}`",
                                                     *tname)[]);
                             }