Remove alternative main feature

Author: cramertj

src/doc/reference.md

@@ -1982,8 +1982,6 @@ type int8_t = i8;
 
 ### Function-only attributes
 
-- `main` - indicates that this function should be passed to the entry point,
-  rather than the function in the crate root named `main`.
 - `plugin_registrar` - mark this function as the registration point for
   [compiler plugins][plugin], such as loadable syntax extensions.
 - `start` - indicates that this function should be used as the entry point,

src/librustc/middle/entry.rs

@@ -94,8 +94,6 @@ fn entry_point_type(item: &Item, at_root: bool) -> EntryPointType {
         ItemFn(..) => {
             if attr::contains_name(&item.attrs, "start") {
                 EntryPointType::Start
-            } else if attr::contains_name(&item.attrs, "main") {
-                EntryPointType::MainAttr
             } else if item.name == "main" {
                 if at_root {
                     // This is a top-level function so can be 'main'

src/libsyntax/entry.rs

@@ -26,8 +26,6 @@ pub fn entry_point_type(item: &Item, depth: usize) -> EntryPointType {
         ItemKind::Fn(..) => {
             if attr::contains_name(&item.attrs, "start") {
                 EntryPointType::Start
-            } else if attr::contains_name(&item.attrs, "main") {
-                EntryPointType::MainAttr
             } else if item.ident.name == "main" {
                 if depth == 1 {
                     // This is a top-level function so can be 'main'

src/libsyntax/feature_gate.rs

@@ -129,7 +129,6 @@ declare_features! (
 
     (active, allocator, "1.0.0", Some(27389)),
     (active, fundamental, "1.0.0", Some(29635)),
-    (active, main, "1.0.0", Some(29634)),
     (active, needs_allocator, "1.4.0", Some(27389)),
     (active, on_unimplemented, "1.0.0", Some(29628)),
     (active, plugin, "1.0.0", Some(29597)),
@@ -334,6 +333,7 @@ declare_features! (
 
 declare_features! (
     (removed, import_shadowing, "1.0.0", None),
+    (removed, main, "1.0.0", Some(29634)),
     (removed, managed_boxes, "1.0.0", None),
     // Allows use of unary negate on unsigned integers, e.g. -e for e: u8
     (removed, negate_unsigned, "1.0.0", Some(29645)),
@@ -468,7 +468,6 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
 
     ("cfg", Normal, Ungated),
     ("cfg_attr", Normal, Ungated),
-    ("main", Normal, Ungated),
     ("start", Normal, Ungated),
     ("test", Normal, Ungated),
     ("bench", Normal, Ungated),
@@ -1106,12 +1105,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                                        feature whose signature may change \
                                        over time");
                 }
-                if attr::contains_name(&i.attrs[..], "main") {
-                    gate_feature_post!(&self, main, i.span,
-                                       "declaration of a nonstandard #[main] \
-                                        function may change over time, for now \
-                                        a top-level `fn main()` is required");
-                }
             }
 
             ast::ItemKind::Struct(..) => {

src/libsyntax/test.rs

@@ -202,9 +202,7 @@ impl fold::Folder for EntryPointCleaner {
                         id: id,
                         ident: ident,
                         attrs: attrs.into_iter()
-                            .filter(|attr| {
-                                !attr.check_name("main") && !attr.check_name("start")
-                            })
+                            .filter(|attr| !attr.check_name("start"))
                             .chain(iter::once(allow_dead_code))
                             .collect(),
                         node: node,

src/test/compile-fail/feature-gate-main.rs

@@ -1,4 +1,4 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -7,13 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
+#![feature(main)] //~ ERROR feature has been removed [E0557]
 
-#![feature(main)]
-
-#[main]
-fn foo() {} //~ NOTE first #[main] function
-
-#[main]
-fn f() {}
-//~^ ERROR E0137
-//~| NOTE additional #[main] function
+#[main] //~ ERROR The attribute `main` is currently unknown to the compiler
+pub fn non_main() {}

src/test/compile-fail/E0137.rs renamed to src/test/compile-fail/issue-29634.rs

@@ -10,7 +10,7 @@
 
 #![allow(unused_variables)]
 #![deny(dead_code)]
-#![feature(main, start)]
+#![feature(start)]
 
 struct Foo;
 
@@ -31,9 +31,6 @@ fn live_fn() {}
 
 fn dead_fn() {} //~ ERROR: function is never used
 
-#[main]
-fn dead_fn2() {} //~ ERROR: function is never used
-
 fn used_fn() {}
 
 #[start]
@@ -47,5 +44,4 @@ fn start(_: isize, _: *const *const u8) -> isize {
 // this is not main
 fn main() { //~ ERROR: function is never used
     dead_fn();
-    dead_fn2();
 }