Rollup of 11 pull requests

Cargo.lock

@@ -3996,6 +3996,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",
+ "rustc_hir_pretty",
  "rustc_index",
  "rustc_infer",
  "rustc_middle",

src/libcore/lib.rs

@@ -96,6 +96,7 @@
 #![feature(custom_inner_attributes)]
 #![feature(decl_macro)]
 #![feature(doc_cfg)]
+#![feature(duration_consts_2)]
 #![feature(extern_types)]
 #![feature(fundamental)]
 #![feature(intrinsics)]

src/libcore/time.rs

@@ -130,10 +130,12 @@ impl Duration {
     /// ```
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
-    #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
-    pub fn new(secs: u64, nanos: u32) -> Duration {
-        let secs =
-            secs.checked_add((nanos / NANOS_PER_SEC) as u64).expect("overflow in Duration::new");
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn new(secs: u64, nanos: u32) -> Duration {
+        let secs = match secs.checked_add((nanos / NANOS_PER_SEC) as u64) {
+            Some(secs) => secs,
+            None => panic!("overflow in Duration::new"),
+        };
         let nanos = nanos % NANOS_PER_SEC;
         Duration { secs, nanos }
     }
@@ -433,7 +435,8 @@ impl Duration {
     /// ```
     #[stable(feature = "duration_checked_ops", since = "1.16.0")]
     #[inline]
-    pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn checked_add(self, rhs: Duration) -> Option<Duration> {
         if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
             let mut nanos = self.nanos + rhs.nanos;
             if nanos >= NANOS_PER_SEC {
@@ -468,7 +471,8 @@ impl Duration {
     /// ```
     #[stable(feature = "duration_checked_ops", since = "1.16.0")]
     #[inline]
-    pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn checked_sub(self, rhs: Duration) -> Option<Duration> {
         if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
             let nanos = if self.nanos >= rhs.nanos {
                 self.nanos - rhs.nanos
@@ -504,19 +508,19 @@ impl Duration {
     /// ```
     #[stable(feature = "duration_checked_ops", since = "1.16.0")]
     #[inline]
-    pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn checked_mul(self, rhs: u32) -> Option<Duration> {
         // Multiply nanoseconds as u64, because it cannot overflow that way.
         let total_nanos = self.nanos as u64 * rhs as u64;
         let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
         let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
-        if let Some(secs) =
-            self.secs.checked_mul(rhs as u64).and_then(|s| s.checked_add(extra_secs))
-        {
-            debug_assert!(nanos < NANOS_PER_SEC);
-            Some(Duration { secs, nanos })
-        } else {
-            None
+        if let Some(s) = self.secs.checked_mul(rhs as u64) {
+            if let Some(secs) = s.checked_add(extra_secs) {
+                debug_assert!(nanos < NANOS_PER_SEC);
+                return Some(Duration { secs, nanos });
+            }
         }
+        None
     }
 
     /// Checked `Duration` division. Computes `self / other`, returning [`None`]
@@ -537,7 +541,8 @@ impl Duration {
     /// ```
     #[stable(feature = "duration_checked_ops", since = "1.16.0")]
     #[inline]
-    pub fn checked_div(self, rhs: u32) -> Option<Duration> {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn checked_div(self, rhs: u32) -> Option<Duration> {
         if rhs != 0 {
             let secs = self.secs / (rhs as u64);
             let carry = self.secs - secs * (rhs as u64);
@@ -563,7 +568,8 @@ impl Duration {
     /// ```
     #[stable(feature = "duration_float", since = "1.38.0")]
     #[inline]
-    pub fn as_secs_f64(&self) -> f64 {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn as_secs_f64(&self) -> f64 {
         (self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64)
     }
 
@@ -580,7 +586,8 @@ impl Duration {
     /// ```
     #[stable(feature = "duration_float", since = "1.38.0")]
     #[inline]
-    pub fn as_secs_f32(&self) -> f32 {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn as_secs_f32(&self) -> f32 {
         (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
     }
 
@@ -747,7 +754,8 @@ impl Duration {
     /// ```
     #[unstable(feature = "div_duration", issue = "63139")]
     #[inline]
-    pub fn div_duration_f64(self, rhs: Duration) -> f64 {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn div_duration_f64(self, rhs: Duration) -> f64 {
         self.as_secs_f64() / rhs.as_secs_f64()
     }
 
@@ -764,7 +772,8 @@ impl Duration {
     /// ```
     #[unstable(feature = "div_duration", issue = "63139")]
     #[inline]
-    pub fn div_duration_f32(self, rhs: Duration) -> f32 {
+    #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
+    pub const fn div_duration_f32(self, rhs: Duration) -> f32 {
         self.as_secs_f32() / rhs.as_secs_f32()
     }
 }

src/librustc_ast_pretty/pprust.rs

@@ -450,9 +450,20 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
     fn print_comment(&mut self, cmnt: &comments::Comment) {
         match cmnt.style {
             comments::Mixed => {
-                assert_eq!(cmnt.lines.len(), 1);
                 self.zerobreak();
-                self.word(cmnt.lines[0].clone());
+                if let Some((last, lines)) = cmnt.lines.split_last() {
+                    self.ibox(0);
+
+                    for line in lines {
+                        self.word(line.clone());
+                        self.hardbreak()
+                    }
+
+                    self.word(last.clone());
+                    self.space();
+
+                    self.end();
+                }
                 self.zerobreak()
             }
             comments::Isolated => {

src/librustc_error_codes/error_codes.rs

@@ -451,6 +451,7 @@ E0765: include_str!("./error_codes/E0765.md"),
 E0766: include_str!("./error_codes/E0766.md"),
 E0767: include_str!("./error_codes/E0767.md"),
 E0768: include_str!("./error_codes/E0768.md"),
+E0769: include_str!("./error_codes/E0769.md"),
 ;
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard

src/librustc_error_codes/error_codes/E0704.md

@@ -1,6 +1,6 @@
-This error indicates that a incorrect visibility restriction was specified.
+An incorrect visibility restriction was specified.
 
-Example of erroneous code:
+Erroneous code example:
 
 ```compile_fail,E0704
 mod foo {
@@ -12,6 +12,7 @@ mod foo {
 
 To make struct `Bar` only visible in module `foo` the `in` keyword should be
 used:
+
 ```
 mod foo {
     pub(in crate::foo) struct Bar {

src/librustc_error_codes/error_codes/E0769.md

@@ -0,0 +1,39 @@
+A tuple struct or tuple variant was used in a pattern as if it were a
+struct or struct variant.
+
+Erroneous code example:
+
+```compile_fail,E0769
+enum E {
+    A(i32),
+}
+let e = E::A(42);
+match e {
+    E::A { number } => println!("{}", x),
+}
+```
+
+To fix this error, you can use the tuple pattern:
+
+```
+# enum E {
+#     A(i32),
+# }
+# let e = E::A(42);
+match e {
+    E::A(number) => println!("{}", number),
+}
+```
+
+Alternatively, you can also use the struct pattern by using the correct
+field names and binding them to new identifiers:
+
+```
+# enum E {
+#     A(i32),
+# }
+# let e = E::A(42);
+match e {
+    E::A { 0: number } => println!("{}", number),
+}
+```

src/librustc_middle/ty/layout.rs

@@ -774,12 +774,12 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> {
                     (present_variants.next(), present_variants.next())
                 };
                 let present_first = match present_first {
-                    present_first @ Some(_) => present_first,
+                    Some(present_first) => present_first,
                     // Uninhabited because it has no variants, or only absent ones.
                     None if def.is_enum() => return tcx.layout_raw(param_env.and(tcx.types.never)),
                     // If it's a struct, still compute a layout so that we can still compute the
                     // field offsets.
-                    None => Some(VariantIdx::new(0)),
+                    None => VariantIdx::new(0),
                 };
 
                 let is_struct = !def.is_enum() ||
@@ -791,7 +791,7 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> {
                     // Struct, or univariant enum equivalent to a struct.
                     // (Typechecking will reject discriminant-sizing attrs.)
 
-                    let v = present_first.unwrap();
+                    let v = present_first;
                     let kind = if def.is_enum() || variants[v].is_empty() {
                         StructKind::AlwaysSized
                     } else {

src/librustc_typeck/Cargo.toml

@@ -18,6 +18,7 @@ rustc_attr = { path = "../librustc_attr" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_hir = { path = "../librustc_hir" }
+rustc_hir_pretty = { path = "../librustc_hir_pretty" }
 rustc_target = { path = "../librustc_target" }
 rustc_session = { path = "../librustc_session" }
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }

src/librustc_typeck/check/cast.rs

@@ -387,6 +387,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                             // Check for infer types because cases like `Option<{integer}>` would
                             // panic otherwise.
                             if !expr_ty.has_infer_types()
+                                && !ty.has_infer_types()
                                 && fcx.tcx.type_implements_trait((
                                     from_trait,
                                     ty,