Auto merge of #48860 - Manishearth:rollup, r=Manishearth

Rollup of 5 pull requests

- Successful merges: #48527, #48588, #48801, #48856, #48857
- Failed merges:

src/librustc/lint/builtin.rs

@@ -17,7 +17,6 @@
 use errors::DiagnosticBuilder;
 use lint::{LintPass, LateLintPass, LintArray};
 use session::Session;
-use session::config::Epoch;
 use syntax::codemap::Span;
 
 declare_lint! {
@@ -264,9 +263,8 @@ declare_lint! {
 
 declare_lint! {
     pub BARE_TRAIT_OBJECT,
-    Warn,
-    "suggest using `dyn Trait` for trait objects",
-    Epoch::Epoch2018
+    Allow,
+    "suggest using `dyn Trait` for trait objects"
 }
 
 declare_lint! {

src/librustc/lint/context.rs

@@ -42,6 +42,7 @@ use util::nodemap::FxHashMap;
 use std::default::Default as StdDefault;
 use std::cell::{Ref, RefCell};
 use syntax::ast;
+use syntax::epoch;
 use syntax_pos::{MultiSpan, Span};
 use errors::DiagnosticBuilder;
 use hir;
@@ -105,7 +106,7 @@ pub struct FutureIncompatibleInfo {
     pub reference: &'static str,
     /// If this is an epoch fixing lint, the epoch in which
     /// this lint becomes obsolete
-    pub epoch: Option<config::Epoch>,
+    pub epoch: Option<epoch::Epoch>,
 }
 
 /// The target of the `by_name` map, which accounts for renaming/deprecation.
@@ -201,7 +202,7 @@ impl LintStore {
                                         sess: Option<&Session>,
                                         lints: Vec<FutureIncompatibleInfo>) {
 
-        for epoch in config::ALL_EPOCHS {
+        for epoch in epoch::ALL_EPOCHS {
             let lints = lints.iter().filter(|f| f.epoch == Some(*epoch)).map(|f| f.id)
                              .collect::<Vec<_>>();
             if !lints.is_empty() {

src/librustc/lint/mod.rs

@@ -38,10 +38,11 @@ use hir::def_id::{CrateNum, LOCAL_CRATE};
 use hir::intravisit::{self, FnKind};
 use hir;
 use lint::builtin::BuiltinLintDiagnostics;
-use session::{config, Session, DiagnosticMessageId};
+use session::{Session, DiagnosticMessageId};
 use std::hash;
 use syntax::ast;
 use syntax::codemap::MultiSpan;
+use syntax::epoch::Epoch;
 use syntax::symbol::Symbol;
 use syntax::visit as ast_visit;
 use syntax_pos::Span;
@@ -77,7 +78,7 @@ pub struct Lint {
     pub desc: &'static str,
 
     /// Deny lint after this epoch
-    pub epoch_deny: Option<config::Epoch>,
+    pub epoch_deny: Option<Epoch>,
 }
 
 impl Lint {
@@ -492,9 +493,14 @@ pub fn struct_lint_level<'a>(sess: &'a Session,
     // Check for future incompatibility lints and issue a stronger warning.
     let lints = sess.lint_store.borrow();
     if let Some(future_incompatible) = lints.future_incompatible(LintId::of(lint)) {
+        let future = if let Some(epoch) = future_incompatible.epoch {
+            format!("the {} epoch", epoch)
+        } else {
+            "a future release".to_owned()
+        };
         let explanation = format!("this was previously accepted by the compiler \
                                    but is being phased out; \
-                                   it will become a hard error in a future release!");
+                                   it will become a hard error in {}!", future);
         let citation = format!("for more information, see {}",
                                future_incompatible.reference);
         err.warn(&explanation);

src/librustc/session/config.rs

@@ -28,6 +28,7 @@ use middle::cstore;
 
 use syntax::ast::{self, IntTy, UintTy};
 use syntax::codemap::{FileName, FilePathMapping};
+use syntax::epoch::Epoch;
 use syntax::parse::token;
 use syntax::parse;
 use syntax::symbol::Symbol;
@@ -111,59 +112,6 @@ pub enum OutputType {
     DepInfo,
 }
 
-/// The epoch of the compiler (RFC 2052)
-#[derive(Clone, Copy, Hash, PartialOrd, Ord, Eq, PartialEq, Debug)]
-#[non_exhaustive]
-pub enum Epoch {
-    // epochs must be kept in order, newest to oldest
-    /// The 2015 epoch
-    Epoch2015,
-    /// The 2018 epoch
-    Epoch2018,
-    // when adding new epochs, be sure to update:
-    //
-    // - the list in the `parse_epoch` static
-    // - the match in the `parse_epoch` function
-    // - add a `rust_####()` function to the session
-    // - update the enum in Cargo's sources as well
-    //
-    // When -Zepoch becomes --epoch, there will
-    // also be a check for the epoch being nightly-only
-    // somewhere. That will need to be updated
-    // whenever we're stabilizing/introducing a new epoch
-    // as well as changing the default Cargo template.
-}
-
-pub const ALL_EPOCHS: &[Epoch] = &[Epoch::Epoch2015, Epoch::Epoch2018];
-
-impl ToString for Epoch {
-    fn to_string(&self) -> String {
-        match *self {
-            Epoch::Epoch2015 => "2015".into(),
-            Epoch::Epoch2018 => "2018".into(),
-        }
-    }
-}
-
-impl Epoch {
-    pub fn lint_name(&self) -> &'static str {
-        match *self {
-            Epoch::Epoch2015 => "epoch_2015",
-            Epoch::Epoch2018 => "epoch_2018",
-        }
-    }
-}
-
-impl str::FromStr for Epoch {
-    type Err = ();
-    fn from_str(s: &str) -> Result<Self, ()> {
-        match s {
-            "2015" => Ok(Epoch::Epoch2015),
-            "2018" => Ok(Epoch::Epoch2018),
-            _ => Err(()),
-        }
-    }
-}
 
 impl_stable_hash_for!(enum self::OutputType {
     Bitcode,
@@ -829,9 +777,10 @@ macro_rules! options {
 
     #[allow(dead_code)]
     mod $mod_set {
-        use super::{$struct_name, Passes, SomePasses, AllPasses, Sanitizer, Lto, Epoch};
+        use super::{$struct_name, Passes, SomePasses, AllPasses, Sanitizer, Lto};
         use rustc_back::{LinkerFlavor, PanicStrategy, RelroLevel};
         use std::path::PathBuf;
+        use syntax::epoch::Epoch;
 
         $(
             pub fn $opt(cg: &mut $struct_name, v: Option<&str>) -> bool {

src/librustc/session/mod.rs

@@ -20,7 +20,7 @@ use lint::builtin::BuiltinLintDiagnostics;
 use middle::allocator::AllocatorKind;
 use middle::dependency_format;
 use session::search_paths::PathKind;
-use session::config::{DebugInfoLevel, Epoch, OutputType};
+use session::config::{DebugInfoLevel, OutputType};
 use ty::tls;
 use util::nodemap::{FxHashMap, FxHashSet};
 use util::common::{duration_to_secs_str, ErrorReported};
@@ -30,6 +30,7 @@ use rustc_data_structures::sync::Lrc;
 use syntax::ast::NodeId;
 use errors::{self, DiagnosticBuilder, DiagnosticId};
 use errors::emitter::{Emitter, EmitterWriter};
+use syntax::epoch::Epoch;
 use syntax::json::JsonEmitter;
 use syntax::feature_gate;
 use syntax::symbol::Symbol;

src/librustc_driver/driver.rs

@@ -647,7 +647,9 @@ pub fn phase_2_configure_and_expand_inner<'a, F>(sess: &'a Session,
 {
     let time_passes = sess.time_passes();
 
-    let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess, sess.opts.test);
+    let (mut krate, features) = syntax::config::features(krate, &sess.parse_sess,
+                                                         sess.opts.test,
+                                                         sess.opts.debugging_opts.epoch);
     // these need to be set "early" so that expansion sees `quote` if enabled.
     sess.init_features(features);
 

src/librustc_errors/Cargo.toml

@@ -13,3 +13,5 @@ serialize = { path = "../libserialize" }
 syntax_pos = { path = "../libsyntax_pos" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 unicode-width = "0.1.4"
+atty = "0.2"
+termcolor = "0.3"