Auto merge of #37128 - nrc:depr-attr, r=@alexcrichton

Deprecate no_debug and custom_derive

r? @nikomatsakis

src/librustc/lint/mod.rs

@@ -314,5 +314,4 @@ pub enum LintSource {
 pub type LevelSource = (Level, LintSource);
 
 pub mod builtin;
-
 mod context;

src/librustc_lint/builtin.rs

@@ -39,12 +39,13 @@
 use rustc::hir::map as hir_map;
 use util::nodemap::NodeSet;
 use lint::{Level, LateContext, LintContext, LintArray, Lint};
-use lint::{LintPass, LateLintPass};
+use lint::{LintPass, LateLintPass, EarlyLintPass, EarlyContext};
 
 use std::collections::HashSet;
 
 use syntax::ast;
 use syntax::attr;
+use syntax::feature_gate::{AttributeGate, AttributeType, Stability, deprecated_attributes};
 use syntax_pos::Span;
 
 use rustc::hir::{self, PatKind};
@@ -741,6 +742,54 @@ fn check_foreign_item_post(&mut self, cx: &LateContext, item: &hir::ForeignItem)
     }
 }
 
+declare_lint! {
+    DEPRECATED_ATTR,
+    Warn,
+    "detects use of deprecated attributes"
+}
+
+/// Checks for use of attributes which have been deprecated.
+#[derive(Clone)]
+pub struct DeprecatedAttr {
+    // This is not free to compute, so we want to keep it around, rather than
+    // compute it for every attribute.
+    depr_attrs: Vec<&'static (&'static str, AttributeType, AttributeGate)>,
+}
+
+impl DeprecatedAttr {
+    pub fn new() -> DeprecatedAttr {
+        DeprecatedAttr {
+            depr_attrs: deprecated_attributes(),
+        }
+    }
+}
+
+impl LintPass for DeprecatedAttr {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(DEPRECATED_ATTR)
+    }
+}
+
+impl EarlyLintPass for DeprecatedAttr {
+    fn check_attribute(&mut self, cx: &EarlyContext, attr: &ast::Attribute) {
+        let name = &*attr.name();
+        for &&(n, _, ref g) in &self.depr_attrs {
+            if n == name {
+                if let &AttributeGate::Gated(Stability::Deprecated(link),
+                                             ref name,
+                                             ref reason,
+                                             _) = g {
+                    cx.span_lint(DEPRECATED,
+                                 attr.span,
+                                 &format!("use of deprecated attribute `{}`: {}. See {}",
+                                          name, reason, link));
+                }
+                return;
+            }
+        }
+    }
+}
+
 declare_lint! {
     pub UNCONDITIONAL_RECURSION,
     Warn,

src/librustc_lint/lib.rs

@@ -37,6 +37,7 @@
 #![feature(rustc_private)]
 #![feature(slice_patterns)]
 #![feature(staged_api)]
+#![feature(dotdot_in_tuple_patterns)]
 
 #[macro_use]
 extern crate syntax;
@@ -95,6 +96,14 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             )
     }
 
+    macro_rules! add_early_builtin_with_new {
+        ($sess:ident, $($name:ident),*,) => (
+            {$(
+                store.register_early_pass($sess, false, box $name::new());
+                )*}
+            )
+    }
+
     macro_rules! add_lint_group {
         ($sess:ident, $name:expr, $($lint:ident),*) => (
             store.register_group($sess, false, $name, vec![$(LintId::of($lint)),*]);
@@ -105,6 +114,10 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
                        UnusedParens,
                        );
 
+    add_early_builtin_with_new!(sess,
+                                DeprecatedAttr,
+                                );
+
     add_builtin!(sess,
                  HardwiredLints,
                  WhileTrue,

src/libsyntax/lib.rs

@@ -34,6 +34,7 @@
 #![cfg_attr(stage0, feature(question_mark))]
 #![feature(rustc_diagnostic_macros)]
 #![feature(specialization)]
+#![feature(dotdot_in_tuple_patterns)]
 
 extern crate serialize;
 extern crate term;

src/libsyntax_ext/deriving/mod.rs

@@ -175,6 +175,7 @@ pub fn expand_derive(cx: &mut ExtCtxt,
                                            feature_gate::GateIssue::Language,
                                            feature_gate::EXPLAIN_CUSTOM_DERIVE);
         } else {
+            cx.span_warn(titem.span, feature_gate::EXPLAIN_DEPR_CUSTOM_DERIVE);
             let name = intern_and_get_ident(&format!("derive_{}", tname));
             let mitem = cx.meta_word(titem.span, name);
             new_attributes.push(cx.attribute(mitem.span, mitem));

src/test/compile-fail/deriving-meta-unknown-trait.rs

@@ -8,8 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-tidy-linelength
+
 #[derive(Eqr)]
-//~^ ERROR `#[derive]` for custom traits is not stable enough for use and is subject to change
+//~^ ERROR `#[derive]` for custom traits is not stable enough for use. It is deprecated and will be removed in v1.15 (see issue #29644)
 struct Foo;
 
 pub fn main() {}

src/test/compile-fail/feature-gate-no-debug-2.rs

+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <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.
+
+#![deny(deprecated)]
+#![feature(no_debug)]
+
+#[no_debug] //~ ERROR use of deprecated attribute `no_debug`
+fn main() {}