Rollup of 10 pull requests

config.toml.example

@@ -138,6 +138,10 @@
 # specified, use this rustc binary instead as the stage0 snapshot compiler.
 #rustc = "/path/to/bin/rustc"
 
+# Instead of download the src/stage0.txt version of rustfmt specified,
+# use this rustfmt binary instead as the stage0 snapshot rustfmt.
+#rustfmt = "/path/to/bin/rustfmt"
+
 # Flag to specify whether any documentation is built. If false, rustdoc and
 # friends will still be compiled but they will not be used to generate any
 # documentation.
@@ -406,6 +410,13 @@
 # Whether to verify generated LLVM IR
 #verify-llvm-ir = false
 
+# Compile the compiler with a non-default ThinLTO import limit. This import
+# limit controls the maximum size of functions imported by ThinLTO. Decreasing
+# will make code compile faster at the expense of lower runtime performance.
+# If `incremental` is set to true above, the import limit will default to 10
+# instead of LLVM's default of 100.
+#thin-lto-import-instr-limit = 100
+
 # Map all debuginfo paths for libstd and crates to `/rust/$sha/$crate/...`,
 # generally only set for releases
 #remap-debuginfo = false

src/bootstrap/builder.rs

@@ -1183,6 +1183,21 @@ impl<'a> Builder<'a> {
             rustflags.arg("-Cprefer-dynamic");
         }
 
+        // When building incrementally we default to a lower ThinLTO import limit
+        // (unless explicitly specified otherwise). This will produce a somewhat
+        // slower code but give way better compile times.
+        {
+            let limit = match self.config.rust_thin_lto_import_instr_limit {
+                Some(limit) => Some(limit),
+                None if self.config.incremental => Some(10),
+                _ => None,
+            };
+
+            if let Some(limit) = limit {
+                rustflags.arg(&format!("-Cllvm-args=-import-instr-limit={}", limit));
+            }
+        }
+
         Cargo { command: cargo, rustflags }
     }
 

src/bootstrap/config.rs

@@ -108,6 +108,7 @@ pub struct Config {
     pub rust_dist_src: bool,
     pub rust_codegen_backends: Vec<Interned<String>>,
     pub rust_verify_llvm_ir: bool,
+    pub rust_thin_lto_import_instr_limit: Option<u32>,
     pub rust_remap_debuginfo: bool,
 
     pub build: Interned<String>,
@@ -202,6 +203,7 @@ struct Build {
     target: Vec<String>,
     cargo: Option<String>,
     rustc: Option<String>,
+    rustfmt: Option<String>, /* allow bootstrap.py to use rustfmt key */
     docs: Option<bool>,
     compiler_docs: Option<bool>,
     submodules: Option<bool>,
@@ -325,6 +327,7 @@ struct Rust {
     deny_warnings: Option<bool>,
     backtrace_on_ice: Option<bool>,
     verify_llvm_ir: Option<bool>,
+    thin_lto_import_instr_limit: Option<u32>,
     remap_debuginfo: Option<bool>,
     jemalloc: Option<bool>,
     test_compare_mode: Option<bool>,
@@ -569,6 +572,7 @@ impl Config {
             set(&mut config.deny_warnings, flags.deny_warnings.or(rust.deny_warnings));
             set(&mut config.backtrace_on_ice, rust.backtrace_on_ice);
             set(&mut config.rust_verify_llvm_ir, rust.verify_llvm_ir);
+            config.rust_thin_lto_import_instr_limit = rust.thin_lto_import_instr_limit;
             set(&mut config.rust_remap_debuginfo, rust.remap_debuginfo);
 
             if let Some(ref backends) = rust.codegen_backends {

src/ci/docker/x86_64-gnu-llvm-7/Dockerfile

@@ -25,7 +25,9 @@ RUN sh /scripts/sccache.sh
 ENV RUST_CONFIGURE_ARGS \
       --build=x86_64-unknown-linux-gnu \
       --llvm-root=/usr/lib/llvm-7 \
-      --enable-llvm-link-shared
+      --enable-llvm-link-shared \
+      --set rust.thin-lto-import-instr-limit=10
+
 ENV SCRIPT python2.7 ../x.py test src/tools/tidy && python2.7 ../x.py test
 
 # The purpose of this container isn't to test with debug assertions and

src/liballoc/tests/arc.rs

@@ -142,7 +142,7 @@ fn shared_from_iter_trustedlen_normal() {
 
     // Try a ZST to make sure it is handled well.
     {
-        let iter = (0..SHARED_ITER_MAX).map(|_| ());
+        let iter = (0..SHARED_ITER_MAX).map(drop);
         let vec = iter.clone().collect::<Vec<_>>();
         let rc = iter.collect::<Rc<[_]>>();
         assert_eq!(&*vec, &*rc);

src/liballoc/tests/rc.rs

@@ -138,7 +138,7 @@ fn shared_from_iter_trustedlen_normal() {
 
     // Try a ZST to make sure it is handled well.
     {
-        let iter = (0..SHARED_ITER_MAX).map(|_| ());
+        let iter = (0..SHARED_ITER_MAX).map(drop);
         let vec = iter.clone().collect::<Vec<_>>();
         let rc = iter.collect::<Rc<[_]>>();
         assert_eq!(&*vec, &*rc);

src/libcore/cmp.rs

@@ -495,7 +495,7 @@ impl<T: Ord> Ord for Reverse<T> {
 ///
 /// An order is a total order if it is (for all `a`, `b` and `c`):
 ///
-/// - total and antisymmetric: exactly one of `a < b`, `a == b` or `a > b` is true; and
+/// - total and asymmetric: exactly one of `a < b`, `a == b` or `a > b` is true; and
 /// - transitive, `a < b` and `b < c` implies `a < c`. The same must hold for both `==` and `>`.
 ///
 /// ## Derivable
@@ -674,7 +674,7 @@ impl PartialOrd for Ordering {
 ///
 /// The comparison must satisfy, for all `a`, `b` and `c`:
 ///
-/// - antisymmetry: if `a < b` then `!(a > b)`, as well as `a > b` implying `!(a < b)`; and
+/// - asymmetry: if `a < b` then `!(a > b)`, as well as `a > b` implying `!(a < b)`; and
 /// - transitivity: `a < b` and `b < c` implies `a < c`. The same must hold for both `==` and `>`.
 ///
 /// Note that these requirements mean that the trait itself must be implemented symmetrically and

src/libcore/mem/mod.rs

@@ -557,7 +557,7 @@ pub fn swap<T>(x: &mut T, y: &mut T) {
     }
 }
 
-/// Replace `dest` with the default value of `T`, and return the previous `dest` value.
+/// Replaces `dest` with the default value of `T`, returning the previous `dest` value.
 ///
 /// # Examples
 ///

src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs

@@ -54,7 +54,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                             err.span_suggestion(
                                 fn_return_span,
                                 &format!(
-                                    "you can add a constraint to the return type to make it last \
+                                    "you can add a bound to the return type to make it last \
                                  less than `'static` and match {}",
                                     lifetime,
                                 ),

src/librustc_error_codes/error_codes/E0130.md

@@ -1,4 +1,4 @@
-You declared a pattern as an argument in a foreign function declaration.
+A pattern was declared as an argument in a foreign function declaration.
 
 Erroneous code example:
 
@@ -9,7 +9,7 @@ extern {
 }
 ```
 
-Please replace the pattern argument with a regular one. Example:
+To fix this error, replace the pattern argument with a regular one. Example:
 
 ```
 struct SomeStruct {

src/librustc_error_codes/error_codes/E0131.md

@@ -1,8 +1,11 @@
-It is not possible to define `main` with generic parameters.
-When `main` is present, it must take no arguments and return `()`.
+The `main` function was defined with generic parameters.
+
 Erroneous code example:
 
 ```compile_fail,E0131
 fn main<T>() { // error: main function is not allowed to have generic parameters
 }
 ```
+
+It is not possible to define the `main` function with generic parameters.
+It must not take any arguments.

src/librustc_mir/borrow_check/diagnostics/explain_borrow.rs

@@ -9,7 +9,7 @@ use rustc::mir::{
 use rustc::ty::adjustment::PointerCast;
 use rustc::ty::{self, TyCtxt};
 use rustc_data_structures::fx::FxHashSet;
-use rustc_errors::DiagnosticBuilder;
+use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_index::vec::IndexVec;
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
@@ -206,6 +206,47 @@ impl BorrowExplanation {
                         ),
                     );
                 };
+
+                self.add_lifetime_bound_suggestion_to_diagnostic(
+                    tcx,
+                    err,
+                    &category,
+                    span,
+                    region_name,
+                );
+            }
+            _ => {}
+        }
+    }
+    pub(in crate::borrow_check) fn add_lifetime_bound_suggestion_to_diagnostic<'tcx>(
+        &self,
+        tcx: TyCtxt<'tcx>,
+        err: &mut DiagnosticBuilder<'_>,
+        category: &ConstraintCategory,
+        span: Span,
+        region_name: &RegionName,
+    ) {
+        match category {
+            ConstraintCategory::OpaqueType => {
+                if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(span) {
+                    let suggestable_name = if region_name.was_named() {
+                        region_name.to_string()
+                    } else {
+                        "'_".to_string()
+                    };
+
+                    err.span_suggestion(
+                        span,
+                        &format!(
+                            "you can add a bound to the {}to make it last less than \
+                             `'static` and match `{}`",
+                            category.description(),
+                            region_name,
+                        ),
+                        format!("{} + {}", snippet, suggestable_name),
+                        Applicability::Unspecified,
+                    );
+                }
             }
             _ => {}
         }

src/librustc_mir/borrow_check/diagnostics/region_errors.rs

@@ -815,7 +815,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                             span,
                             &format!(
                                 "to allow this `impl Trait` to capture borrowed data with lifetime \
-                                 `{}`, add `{}` as a constraint",
+                                 `{}`, add `{}` as a bound",
                                 fr_name, suggestable_fr_name,
                             ),
                             format!("{} + {}", snippet, suggestable_fr_name),

src/librustc_mir/hair/pattern/check_match.rs

@@ -284,7 +284,7 @@ fn check_for_bindings_named_same_as_variants(cx: &MatchVisitor<'_, '_>, pat: &Pa
             if let Some(ty::BindByValue(hir::Mutability::Not)) =
                 cx.tables.extract_binding_mode(cx.tcx.sess, p.hir_id, p.span)
             {
-                let pat_ty = cx.tables.pat_ty(p);
+                let pat_ty = cx.tables.pat_ty(p).peel_refs();
                 if let ty::Adt(edef, _) = pat_ty.kind {
                     if edef.is_enum()
                         && edef.variants.iter().any(|variant| {

src/librustc_mir/transform/inline.rs

@@ -671,12 +671,7 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Integrator<'a, 'tcx> {
         *local = self.make_integrate_local(local);
     }
 
-    fn visit_place(
-        &mut self,
-        place: &mut Place<'tcx>,
-        _context: PlaceContext,
-        _location: Location,
-    ) {
+    fn visit_place(&mut self, place: &mut Place<'tcx>, context: PlaceContext, location: Location) {
         match &mut place.base {
             PlaceBase::Static(_) => {}
             PlaceBase::Local(l) => {
@@ -689,10 +684,11 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Integrator<'a, 'tcx> {
 
                     place.projection = self.tcx.intern_place_elems(&*projs);
                 }
-
-                *l = self.make_integrate_local(l);
             }
         }
+        // Handles integrating any locals that occur in the base
+        // or projections
+        self.super_place(place, context, location)
     }
 
     fn process_projection_elem(&mut self, elem: &PlaceElem<'tcx>) -> Option<PlaceElem<'tcx>> {

src/librustc_parse/parser/diagnostics.rs

@@ -848,7 +848,7 @@ impl<'a> Parser<'a> {
         let appl = Applicability::MachineApplicable;
         if self.token.span == DUMMY_SP || self.prev_span == DUMMY_SP {
             // Likely inside a macro, can't provide meaninful suggestions.
-            return self.expect(&token::Semi).map(|_| ());
+            return self.expect(&token::Semi).map(drop);
         } else if !sm.is_multiline(self.prev_span.until(self.token.span)) {
             // The current token is in the same line as the prior token, not recoverable.
         } else if self.look_ahead(1, |t| {
@@ -887,7 +887,7 @@ impl<'a> Parser<'a> {
                 .emit();
             return Ok(());
         }
-        self.expect(&token::Semi).map(|_| ()) // Error unconditionally
+        self.expect(&token::Semi).map(drop) // Error unconditionally
     }
 
     pub(super) fn parse_semi_or_incorrect_foreign_fn_body(

src/libstd/io/buffered.rs

@@ -232,7 +232,7 @@ impl<R: Seek> BufReader<R> {
                 }
             }
         }
-        self.seek(SeekFrom::Current(offset)).map(|_| ())
+        self.seek(SeekFrom::Current(offset)).map(drop)
     }
 }
 

src/libstd/sys/unix/android.rs

@@ -93,12 +93,12 @@ pub fn ftruncate64(fd: c_int, size: u64) -> io::Result<()> {
 
     unsafe {
         match ftruncate64.get() {
-            Some(f) => cvt_r(|| f(fd, size as i64)).map(|_| ()),
+            Some(f) => cvt_r(|| f(fd, size as i64)).map(drop),
             None => {
                 if size > i32::max_value() as u64 {
                     Err(io::Error::new(io::ErrorKind::InvalidInput, "cannot truncate >2GB"))
                 } else {
-                    cvt_r(|| ftruncate(fd, size as i32)).map(|_| ())
+                    cvt_r(|| ftruncate(fd, size as i32)).map(drop)
                 }
             }
         }
@@ -107,7 +107,7 @@ pub fn ftruncate64(fd: c_int, size: u64) -> io::Result<()> {
 
 #[cfg(target_pointer_width = "64")]
 pub fn ftruncate64(fd: c_int, size: u64) -> io::Result<()> {
-    unsafe { cvt_r(|| ftruncate(fd, size as i64)).map(|_| ()) }
+    unsafe { cvt_r(|| ftruncate(fd, size as i64)).map(drop) }
 }
 
 #[cfg(target_pointer_width = "32")]

src/libstd/sys/unix/fs.rs

@@ -814,7 +814,7 @@ impl File {
             use crate::convert::TryInto;
             let size: off64_t =
                 size.try_into().map_err(|e| io::Error::new(io::ErrorKind::InvalidInput, e))?;
-            cvt_r(|| unsafe { ftruncate64(self.0.raw(), size) }).map(|_| ())
+            cvt_r(|| unsafe { ftruncate64(self.0.raw(), size) }).map(drop)
         }
     }
 

src/libstd/sys/unix/net.rs

@@ -324,7 +324,7 @@ impl Socket {
 
     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
         let mut nonblocking = nonblocking as libc::c_int;
-        cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(|_| ())
+        cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(drop)
     }
 
     pub fn take_error(&self) -> io::Result<Option<io::Error>> {

src/libstd/sys/unix/os.rs

@@ -529,7 +529,7 @@ pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
 
     unsafe {
         let _guard = env_lock();
-        cvt(libc::setenv(k.as_ptr(), v.as_ptr(), 1)).map(|_| ())
+        cvt(libc::setenv(k.as_ptr(), v.as_ptr(), 1)).map(drop)
     }
 }
 
@@ -538,7 +538,7 @@ pub fn unsetenv(n: &OsStr) -> io::Result<()> {
 
     unsafe {
         let _guard = env_lock();
-        cvt(libc::unsetenv(nbuf.as_ptr())).map(|_| ())
+        cvt(libc::unsetenv(nbuf.as_ptr())).map(drop)
     }
 }
 

src/libstd/sys/unix/pipe.rs

@@ -99,11 +99,11 @@ pub fn read2(p1: AnonPipe, v1: &mut Vec<u8>, p2: AnonPipe, v2: &mut Vec<u8>) ->
 
         if fds[0].revents != 0 && read(&p1, v1)? {
             p2.set_nonblocking(false)?;
-            return p2.read_to_end(v2).map(|_| ());
+            return p2.read_to_end(v2).map(drop);
         }
         if fds[1].revents != 0 && read(&p2, v2)? {
             p1.set_nonblocking(false)?;
-            return p1.read_to_end(v1).map(|_| ());
+            return p1.read_to_end(v1).map(drop);
         }
     }
 

src/libstd/sys/unix/process/process_unix.rs

@@ -425,7 +425,7 @@ impl Process {
                 "invalid argument: can't kill an exited process",
             ))
         } else {
-            cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(|_| ())
+            cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(drop)
         }
     }
 

src/libstd/sys/vxworks/fs.rs

@@ -340,7 +340,7 @@ impl File {
     }
 
     pub fn truncate(&self, size: u64) -> io::Result<()> {
-        return cvt_r(|| unsafe { ftruncate(self.0.raw(), size as off_t) }).map(|_| ());
+        return cvt_r(|| unsafe { ftruncate(self.0.raw(), size as off_t) }).map(drop);
     }
 
     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {