Rollup of 8 pull requests

src/libcore/lib.rs

@@ -133,7 +133,7 @@
 #![feature(associated_type_bounds)]
 #![feature(const_type_id)]
 #![feature(const_caller_location)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 
 #[prelude_import]
 #[allow(unused)]

src/libcore/tests/lib.rs

@@ -19,7 +19,7 @@
 #![feature(range_is_empty)]
 #![feature(raw)]
 #![feature(saturating_neg)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![feature(sort_internals)]
 #![feature(slice_partition_at_index)]
 #![feature(specialization)]

src/librustc/benches/lib.rs

@@ -1,4 +1,4 @@
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![feature(test)]
 
 extern crate test;

src/librustc/lib.rs

@@ -42,7 +42,7 @@
 #![feature(optin_builtin_traits)]
 #![feature(option_expect_none)]
 #![feature(range_is_empty)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![feature(specialization)]
 #![feature(unboxed_closures)]
 #![feature(thread_local)]

src/librustc_ast_passes/feature_gate.rs

@@ -470,29 +470,8 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
         visit::walk_expr(self, e)
     }
 
-    fn visit_arm(&mut self, arm: &'a ast::Arm) {
-        visit::walk_arm(self, arm)
-    }
-
     fn visit_pat(&mut self, pattern: &'a ast::Pat) {
         match &pattern.kind {
-            PatKind::Slice(pats) => {
-                for pat in &*pats {
-                    let span = pat.span;
-                    let inner_pat = match &pat.kind {
-                        PatKind::Ident(.., Some(pat)) => pat,
-                        _ => pat,
-                    };
-                    if inner_pat.is_rest() {
-                        gate_feature_post!(
-                            &self,
-                            slice_patterns,
-                            span,
-                            "subslice patterns are unstable"
-                        );
-                    }
-                }
-            }
             PatKind::Box(..) => {
                 gate_feature_post!(
                     &self,

src/librustc_ast_passes/lib.rs

@@ -2,7 +2,7 @@
 //! parsed by `rustc_parse` and then lowered, after the passes in this crate,
 //! by `rustc_ast_lowering`.
 
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 
 pub mod ast_validation;
 pub mod feature_gate;

src/librustc_codegen_ssa/lib.rs

@@ -4,7 +4,7 @@
 #![feature(box_syntax)]
 #![feature(core_intrinsics)]
 #![feature(libc)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![feature(stmt_expr_attributes)]
 #![feature(try_blocks)]
 #![feature(in_band_lifetimes)]

src/librustc_error_codes/error_codes/E0198.md

@@ -1,17 +1,18 @@
-A negative implementation is one that excludes a type from implementing a
-particular trait. Not being able to use a trait is always a safe operation,
-so negative implementations are always safe and never need to be marked as
-unsafe.
+A negative implementation was marked as unsafe.
 
-```compile_fail
-#![feature(optin_builtin_traits)]
+Erroneous code example:
 
+```compile_fail
 struct Foo;
 
-// unsafe is unnecessary
-unsafe impl !Clone for Foo { }
+unsafe impl !Clone for Foo { } // error!
 ```
 
+A negative implementation is one that excludes a type from implementing a
+particular trait. Not being able to use a trait is always a safe operation,
+so negative implementations are always safe and never need to be marked as
+unsafe.
+
 This will compile:
 
 ```ignore (ignore auto_trait future compatibility warning)

src/librustc_error_codes/error_codes/E0199.md

@@ -1,14 +1,23 @@
+A trait implementation was marked as unsafe while the trait is safe.
+
+Erroneous code example:
+
+```compile_fail,E0199
+struct Foo;
+
+trait Bar { }
+
+unsafe impl Bar for Foo { } // error!
+```
+
 Safe traits should not have unsafe implementations, therefore marking an
 implementation for a safe trait unsafe will cause a compiler error. Removing
-the unsafe marker on the trait noted in the error will resolve this problem.
+the unsafe marker on the trait noted in the error will resolve this problem:
 
-```compile_fail,E0199
+```
 struct Foo;
 
 trait Bar { }
 
-// this won't compile because Bar is safe
-unsafe impl Bar for Foo { }
-// this will compile
-impl Bar for Foo { }
+impl Bar for Foo { } // ok!
 ```

src/librustc_error_codes/error_codes/E0527.md

@@ -17,8 +17,6 @@ Ensure that the pattern is consistent with the size of the matched
 array. Additional elements can be matched with `..`:
 
 ```
-#![feature(slice_patterns)]
-
 let r = &[1, 2, 3, 4];
 match r {
     &[a, b, ..] => { // ok!

src/librustc_error_codes/error_codes/E0528.md

@@ -4,8 +4,6 @@ matched array.
 Example of erroneous code:
 
 ```compile_fail,E0528
-#![feature(slice_patterns)]
-
 let r = &[1, 2];
 match r {
     &[a, b, c, rest @ ..] => { // error: pattern requires at least 3
@@ -19,8 +17,6 @@ Ensure that the matched array has at least as many elements as the pattern
 requires. You can match an arbitrary number of remaining elements with `..`:
 
 ```
-#![feature(slice_patterns)]
-
 let r = &[1, 2, 3, 4, 5];
 match r {
     &[a, b, c, rest @ ..] => { // ok!

src/librustc_error_codes/error_codes/E0730.md

@@ -18,8 +18,6 @@ Ensure that the pattern is consistent with the size of the matched
 array. Additional elements can be matched with `..`:
 
 ```
-#![feature(slice_patterns)]
-
 let r = &[1, 2, 3, 4];
 match r {
     &[a, b, ..] => { // ok!

src/librustc_errors/emitter.rs

@@ -1476,6 +1476,15 @@ impl EmitterWriter {
             None => return Ok(()),
         };
 
+        // Render the replacements for each suggestion
+        let suggestions = suggestion.splice_lines(&**sm);
+
+        if suggestions.is_empty() {
+            // Suggestions coming from macros can have malformed spans. This is a heavy handed
+            // approach to avoid ICEs by ignoring the suggestion outright.
+            return Ok(());
+        }
+
         let mut buffer = StyledBuffer::new();
 
         // Render the suggestion message
@@ -1492,9 +1501,6 @@ impl EmitterWriter {
             Some(Style::HeaderMsg),
         );
 
-        // Render the replacements for each suggestion
-        let suggestions = suggestion.splice_lines(&**sm);
-
         let mut row_num = 2;
         let mut notice_capitalization = false;
         for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) {
@@ -1505,7 +1511,9 @@ impl EmitterWriter {
             let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim())
                 && complete.lines().count() == 1;
 
-            let lines = sm.span_to_lines(parts[0].span).unwrap();
+            let lines = sm
+                .span_to_lines(parts[0].span)
+                .expect("span_to_lines failed when emitting suggestion");
 
             assert!(!lines.lines.is_empty());
 

src/librustc_errors/lib.rs

@@ -10,6 +10,7 @@
 
 pub use emitter::ColorConfig;
 
+use log::debug;
 use Level::*;
 
 use emitter::{is_case_difference, Emitter, EmitterWriter};
@@ -174,6 +175,15 @@ impl CodeSuggestion {
 
         self.substitutions
             .iter()
+            .filter(|subst| {
+                // Suggestions coming from macros can have malformed spans. This is a heavy
+                // handed approach to avoid ICEs by ignoring the suggestion outright.
+                let invalid = subst.parts.iter().any(|item| cm.is_valid_span(item.span).is_err());
+                if invalid {
+                    debug!("splice_lines: suggestion contains an invalid span: {:?}", subst);
+                }
+                !invalid
+            })
             .cloned()
             .map(|mut substitution| {
                 // Assumption: all spans are in the same file, and all spans

src/librustc_feature/accepted.rs

@@ -257,6 +257,8 @@ declare_features! (
     /// Allows relaxing the coherence rules such that
     /// `impl<T> ForeignTrait<LocalType> for ForeignType<T>` is permitted.
     (accepted, re_rebalance_coherence, "1.41.0", Some(55437), None),
+    /// Allows using subslice patterns, `[a, .., b]` and `[a, xs @ .., b]`.
+    (accepted, slice_patterns, "1.42.0", Some(62254), None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: accepted features

src/librustc_feature/active.rs

@@ -262,9 +262,6 @@ declare_features! (
     /// Allows using non lexical lifetimes (RFC 2094).
     (active, nll, "1.0.0", Some(43234), None),
 
-    /// Allows using slice patterns.
-    (active, slice_patterns, "1.0.0", Some(62254), None),
-
     /// Allows the definition of `const` functions with some advanced features.
     (active, const_fn, "1.2.0", Some(57563), None),
 

src/librustc_lint/nonstandard_style.rs

@@ -350,7 +350,20 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonSnakeCase {
     }
 
     fn check_pat(&mut self, cx: &LateContext<'_, '_>, p: &hir::Pat<'_>) {
-        if let &PatKind::Binding(_, _, ident, _) = &p.kind {
+        if let &PatKind::Binding(_, hid, ident, _) = &p.kind {
+            if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
+            {
+                if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
+                    for field in field_pats.iter() {
+                        if field.ident != ident {
+                            // Only check if a new name has been introduced, to avoid warning
+                            // on both the struct definition and this pattern.
+                            self.check_snake_case(cx, "variable", &ident);
+                        }
+                    }
+                    return;
+                }
+            }
             self.check_snake_case(cx, "variable", &ident);
         }
     }

src/librustc_metadata/lib.rs

@@ -10,7 +10,7 @@
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![feature(rustc_private)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![feature(specialization)]
 #![feature(stmt_expr_attributes)]
 #![recursion_limit = "256"]

src/librustc_mir/lib.rs

@@ -7,7 +7,7 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(nll)]
 #![feature(in_band_lifetimes)]
 #![feature(inner_deref)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]

src/librustc_mir/transform/qualify_min_const_fn.rs

@@ -309,21 +309,22 @@ fn check_terminator(
 ) -> McfResult {
     let span = terminator.source_info.span;
     match &terminator.kind {
-        TerminatorKind::Goto { .. } | TerminatorKind::Return | TerminatorKind::Resume => Ok(()),
+        TerminatorKind::FalseEdges { .. }
+        | TerminatorKind::FalseUnwind { .. }
+        | TerminatorKind::Goto { .. }
+        | TerminatorKind::Return
+        | TerminatorKind::Resume => Ok(()),
 
         TerminatorKind::Drop { location, .. } => check_place(tcx, location, span, def_id, body),
         TerminatorKind::DropAndReplace { location, value, .. } => {
             check_place(tcx, location, span, def_id, body)?;
             check_operand(tcx, value, span, def_id, body)
         }
 
-        TerminatorKind::FalseEdges { .. } | TerminatorKind::SwitchInt { .. }
-            if !feature_allowed(tcx, def_id, sym::const_if_match) =>
-        {
+        TerminatorKind::SwitchInt { .. } if !feature_allowed(tcx, def_id, sym::const_if_match) => {
             Err((span, "loops and conditional expressions are not stable in const fn".into()))
         }
 
-        TerminatorKind::FalseEdges { .. } => Ok(()),
         TerminatorKind::SwitchInt { discr, switch_ty: _, values: _, targets: _ } => {
             check_operand(tcx, discr, span, def_id, body)
         }
@@ -367,13 +368,5 @@ fn check_terminator(
         TerminatorKind::Assert { cond, expected: _, msg: _, target: _, cleanup: _ } => {
             check_operand(tcx, cond, span, def_id, body)
         }
-
-        TerminatorKind::FalseUnwind { .. } if feature_allowed(tcx, def_id, sym::const_loop) => {
-            Ok(())
-        }
-
-        TerminatorKind::FalseUnwind { .. } => {
-            Err((span, "loops are not allowed in const fn".into()))
-        }
     }
 }

src/librustc_parse/lib.rs

@@ -2,7 +2,7 @@
 
 #![feature(bool_to_option)]
 #![feature(crate_visibility_modifier)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 
 use syntax::ast;
 use syntax::print::pprust;

src/librustc_passes/lib.rs

@@ -7,7 +7,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
-#![feature(slice_patterns)]
+#![cfg_attr(bootstrap, feature(slice_patterns))]
 #![recursion_limit = "256"]
 
 #[macro_use]