Auto merge of #52931 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 31 pull requests

Successful merges:

 - #52332 (dead-code lint: say "constructed" for structs)
 - #52340 (Document From trait implementations for OsStr, OsString, CString, and CStr)
 - #52628 (Cleanup some rustdoc code)
 - #52732 (Remove unstable and deprecated APIs)
 - #52745 (Update clippy to latest master)
 - #52756 (rustc: Disallow machine applicability in foreign macros)
 - #52771 (Clarify thread::park semantics)
 - #52810 ([NLL] Don't make "fake" match variables mutable)
 - #52821 (pretty print for std::collections::vecdeque)
 - #52822 (Fix From<LocalWaker>)
 - #52824 (Fix -Wpessimizing-move warnings in rustllvm/PassWrapper)
 - #52831 (remove references to AUTHORS.txt file)
 - #52835 (Fix Alias intra doc ICE)
 - #52842 (update comment)
 - #52846 (Add timeout to use of `curl` in bootstrap.py.)
 - #52851 (Make the tool_lints actually usable)
 - #52853 (Improve bootstrap help on stages)
 - #52859 (Use Vec::extend in SmallVec::extend when applicable)
 - #52861 (Add targets for HermitCore (https://hermitcore.org) to the Rust compiler and port libstd to it.)
 - #52867 (releases.md: fix 2 typos)
 - #52870 (Implement Unpin for FutureObj and LocalFutureObj)
 - #52876 (run-pass/const-endianness: negate before to_le())
 - #52878 (Fix wrong issue number in the test name)
 - #52883 (Include lifetime in mutability suggestion in NLL messages)
 - #52904 (NLL: sort diagnostics by span)
 - #52905 (Fix a typo in unsize.rs)
 - #52907 (NLL: On "cannot move out of type" error, print original before rewrite)
 - #52908 (Use SetLenOnDrop in Vec::truncate())
 - #52914 (Only run the sparc-abi test on sparc)
 - #52918 (Backport 1.27.2 release notes)
 - #52929 (Update compatibility note for 1.28.0 to be correct)

Failed merges:

 - #52758 (Cleanup for librustc::session)
 - #52799 (Use BitVector for global sets of AttrId)

r? @ghost

COPYRIGHT

@@ -10,8 +10,8 @@ Copyrights in the Rust project are retained by their contributors. No
 copyright assignment is required to contribute to the Rust project.
 
 Some files include explicit copyright notices and/or license notices.
-For full authorship information, see AUTHORS.txt and the version control
-history.
+For full authorship information, see the version control history or
+https://thanks.rust-lang.org
 
 Except as otherwise noted (below and/or in individual files), Rust is
 licensed under the Apache License, Version 2.0 <LICENSE-APACHE> or

RELEASES.md

@@ -94,9 +94,9 @@ Misc
 
 Compatibility Notes
 -------------------
-- [Rust will no longer consider trait objects with duplicated constraints to
-  have implementations.][51276] For example the below code will now fail
-  to compile.
+- [Rust will consider trait objects with duplicated constraints to be the same
+  type as without the duplicated constraint.][51276] For example the below code will
+  now fail to compile.
   ```rust
   trait Trait {}
 
@@ -160,6 +160,17 @@ Compatibility Notes
 [`{Any + Send + Sync}::downcast_ref`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.downcast_ref-2
 [`{Any + Send + Sync}::is`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.is-2
 
+Version 1.27.2 (2018-07-20)
+===========================
+
+Compatibility Notes
+-------------------
+
+- The borrow checker was fixed to avoid potential unsoundness when using
+  match ergonomics: [#52213][52213].
+
+[52213]: https://github.com/rust-lang/rust/issues/52213
+
 Version 1.27.1 (2018-07-10)
 ===========================
 
@@ -190,7 +201,7 @@ Version 1.27.0 (2018-06-21)
 Language
 --------
 - [Removed 'proc' from the reserved keywords list.][49699] This allows `proc` to
-  be used as an identifer.
+  be used as an identifier.
 - [The dyn syntax is now available.][49968] This syntax is equivalent to the
   bare `Trait` syntax, and should make it clearer when being used in tandem with
   `impl Trait`. Since it is equivalent to the following syntax:
@@ -4795,7 +4806,7 @@ Language
 --------
 
 * Patterns with `ref mut` now correctly invoke [`DerefMut`] when
-  matching against dereferencable values.
+  matching against dereferenceable values.
 
 Libraries
 ---------

src/Cargo.lock

@@ -2612,18 +2612,9 @@ dependencies = [
  "rustc_lsan 0.0.0",
  "rustc_msan 0.0.0",
  "rustc_tsan 0.0.0",
- "std_unicode 0.0.0",
  "unwind 0.0.0",
 ]
 
-[[package]]
-name = "std_unicode"
-version = "0.0.0"
-dependencies = [
- "compiler_builtins 0.0.0",
- "core 0.0.0",
-]
-
 [[package]]
 name = "string_cache"
 version = "0.7.3"

src/bootstrap/bootstrap.py

@@ -88,7 +88,10 @@ def _download(path, url, probably_big, verbose, exception):
             option = "-#"
         else:
             option = "-s"
-        run(["curl", option, "--retry", "3", "-Sf", "-o", path, url],
+        run(["curl", option,
+             "-y", "30", "-Y", "10",    # timeout if speed is < 10 bytes/sec for > 30 seconds
+             "--connect-timeout", "30", # timeout if cannot connect within 30 seconds
+             "--retry", "3", "-Sf", "-o", path, url],
             verbose=verbose,
             exception=exception)
 

src/bootstrap/compile.rs

@@ -157,7 +157,6 @@ pub fn std_cargo(builder: &Builder,
         cargo.arg("--features").arg("c mem")
             .args(&["-p", "alloc"])
             .args(&["-p", "compiler_builtins"])
-            .args(&["-p", "std_unicode"])
             .arg("--manifest-path")
             .arg(builder.src.join("src/rustc/compiler_builtins_shim/Cargo.toml"));
     } else {

src/bootstrap/dist.rs

@@ -856,7 +856,6 @@ impl Step for Src {
             "src/librustc_msan",
             "src/librustc_tsan",
             "src/libstd",
-            "src/libstd_unicode",
             "src/libunwind",
             "src/rustc/compiler_builtins_shim",
             "src/rustc/libc_shim",

src/bootstrap/doc.rs

@@ -489,7 +489,7 @@ impl Step for Std {
         // Keep a whitelist so we do not build internal stdlib crates, these will be
         // build by the rustc step later if enabled.
         cargo.arg("--no-deps");
-        for krate in &["alloc", "core", "std", "std_unicode"] {
+        for krate in &["alloc", "core", "std"] {
             cargo.arg("-p").arg(krate);
             // Create all crate output directories first to make sure rustdoc uses
             // relative links.

src/bootstrap/flags.rs

@@ -121,7 +121,10 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`"
         opts.optmulti("", "exclude", "build paths to exclude", "PATH");
         opts.optopt("", "on-fail", "command to run on failure", "CMD");
         opts.optflag("", "dry-run", "dry run; don't build anything");
-        opts.optopt("", "stage", "stage to build", "N");
+        opts.optopt("", "stage",
+            "stage to build (indicates compiler to use/test, e.g. stage 0 uses the \
+             bootstrap compiler, stage 1 the stage 0 rustc artifacts, etc.)",
+            "N");
         opts.optmulti("", "keep-stage", "stage(s) to keep without recompiling", "N");
         opts.optopt("", "src", "path to the root of the rust checkout", "DIR");
         opts.optopt("j", "jobs", "number of jobs to run in parallel", "JOBS");
@@ -258,7 +261,7 @@ Arguments:
 
         ./x.py build --stage 1 src/libtest
 
-    This will first build everything once (like --stage 0 without further
+    This will first build everything once (like `--stage 0` without further
     arguments would), and then use the compiler built in stage 0 to build
     src/libtest and its dependencies.
     Once this is done, build/$ARCH/stage1 contains a usable compiler.",
@@ -290,10 +293,14 @@ Arguments:
 
         ./x.py test src/test/run-pass
         ./x.py test src/libstd --test-args hash_map
-        ./x.py test src/libstd --stage 0
+        ./x.py test src/libstd --stage 0 --no-doc
         ./x.py test src/test/ui --bless
         ./x.py test src/test/ui --compare-mode nll
 
+    Note that `test src/test/* --stage N` does NOT depend on `build src/rustc --stage N`;
+    just like `build src/libstd --stage N` it tests the compiler produced by the previous
+    stage.
+
     If no arguments are passed then the complete artifacts for that stage are
     compiled and tested.
 

src/doc/man/rustdoc.1

@@ -119,7 +119,7 @@ See <\fBhttps://github.com/rust\-lang/rust/issues\fR>
 for issues.
 
 .SH "AUTHOR"
-See \fIAUTHORS.txt\fR in the Rust source distribution.
+See the version control history or <\fBhttps://thanks.rust\-lang.org\fR>
 
 .SH "COPYRIGHT"
 This work is dual\[hy]licensed under Apache\ 2.0 and MIT terms.

src/etc/debugger_pretty_printers_common.py

@@ -47,6 +47,7 @@
 TYPE_KIND_FIXED_SIZE_VEC    = 16
 TYPE_KIND_REGULAR_UNION     = 17
 TYPE_KIND_OS_STRING         = 18
+TYPE_KIND_STD_VECDEQUE      = 19
 
 ENCODED_ENUM_PREFIX = "RUST$ENCODED$ENUM$"
 ENUM_DISR_FIELD_NAME = "RUST$ENUM$DISR"
@@ -62,6 +63,14 @@
 STD_VEC_FIELD_NAMES = [STD_VEC_FIELD_NAME_BUF,
                        STD_VEC_FIELD_NAME_LENGTH]
 
+# std::collections::VecDeque<> related constants
+STD_VECDEQUE_FIELD_NAME_TAIL = "tail"
+STD_VECDEQUE_FIELD_NAME_HEAD = "head"
+STD_VECDEQUE_FIELD_NAME_BUF = "buf"
+STD_VECDEQUE_FIELD_NAMES = [STD_VECDEQUE_FIELD_NAME_TAIL,
+                            STD_VECDEQUE_FIELD_NAME_HEAD,
+                            STD_VECDEQUE_FIELD_NAME_BUF]
+
 # std::String related constants
 STD_STRING_FIELD_NAMES = ["vec"]
 
@@ -161,6 +170,11 @@ def __classify_struct(self):
             self.__conforms_to_field_layout(STD_VEC_FIELD_NAMES)):
             return TYPE_KIND_STD_VEC
 
+        # STD COLLECTION VECDEQUE
+        if (unqualified_type_name.startswith("VecDeque<") and
+            self.__conforms_to_field_layout(STD_VECDEQUE_FIELD_NAMES)):
+            return TYPE_KIND_STD_VECDEQUE
+
         # STD STRING
         if (unqualified_type_name.startswith("String") and
             self.__conforms_to_field_layout(STD_STRING_FIELD_NAMES)):
@@ -325,6 +339,25 @@ def extract_length_ptr_and_cap_from_std_vec(vec_val):
     assert data_ptr.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_PTR
     return (length, data_ptr, capacity)
 
+
+def extract_tail_head_ptr_and_cap_from_std_vecdeque(vec_val):
+    assert vec_val.type.get_type_kind() == TYPE_KIND_STD_VECDEQUE
+    tail_field_index = STD_VECDEQUE_FIELD_NAMES.index(STD_VECDEQUE_FIELD_NAME_TAIL)
+    head_field_index = STD_VECDEQUE_FIELD_NAMES.index(STD_VECDEQUE_FIELD_NAME_HEAD)
+    buf_field_index = STD_VECDEQUE_FIELD_NAMES.index(STD_VECDEQUE_FIELD_NAME_BUF)
+
+    tail = vec_val.get_child_at_index(tail_field_index).as_integer()
+    head = vec_val.get_child_at_index(head_field_index).as_integer()
+    buf = vec_val.get_child_at_index(buf_field_index)
+
+    vec_ptr_val = buf.get_child_at_index(0)
+    capacity = buf.get_child_at_index(1).as_integer()
+    unique_ptr_val = vec_ptr_val.get_child_at_index(0)
+    data_ptr = unique_ptr_val.get_child_at_index(0)
+    assert data_ptr.type.get_dwarf_type_kind() == DWARF_TYPE_CODE_PTR
+    return (tail, head, data_ptr, capacity)
+
+
 def extract_length_and_ptr_from_slice(slice_val):
     assert (slice_val.type.get_type_kind() == TYPE_KIND_SLICE or
             slice_val.type.get_type_kind() == TYPE_KIND_STR_SLICE)

src/etc/gdb_rust_pretty_printing.py

@@ -124,6 +124,9 @@ def rust_pretty_printer_lookup_function(gdb_val):
     if type_kind == rustpp.TYPE_KIND_STD_VEC:
         return RustStdVecPrinter(val)
 
+    if type_kind == rustpp.TYPE_KIND_STD_VECDEQUE:
+        return RustStdVecDequePrinter(val)
+
     if type_kind == rustpp.TYPE_KIND_STD_STRING:
         return RustStdStringPrinter(val)
 
@@ -274,6 +277,28 @@ def children(self):
             yield (str(index), (gdb_ptr + index).dereference())
 
 
+class RustStdVecDequePrinter(object):
+    def __init__(self, val):
+        self.__val = val
+
+    @staticmethod
+    def display_hint():
+        return "array"
+
+    def to_string(self):
+        (tail, head, data_ptr, cap) = \
+            rustpp.extract_tail_head_ptr_and_cap_from_std_vecdeque(self.__val)
+        return (self.__val.type.get_unqualified_type_name() +
+                ("(len: %i, cap: %i)" % (head - tail, cap)))
+
+    def children(self):
+        (tail, head, data_ptr, cap) = \
+            rustpp.extract_tail_head_ptr_and_cap_from_std_vecdeque(self.__val)
+        gdb_ptr = data_ptr.get_wrapped_value()
+        for index in xrange(tail, head):
+            yield (str(index), (gdb_ptr + index).dereference())
+
+
 class RustStdStringPrinter(object):
     def __init__(self, val):
         self.__val = val

src/liballoc/vec.rs

@@ -690,14 +690,20 @@ impl<T> Vec<T> {
     /// [`drain`]: #method.drain
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn truncate(&mut self, len: usize) {
+        let current_len = self.len;
         unsafe {
+            let mut ptr = self.as_mut_ptr().offset(self.len as isize);
+            // Set the final length at the end, keeping in mind that
+            // dropping an element might panic. Works around a missed
+            // optimization, as seen in the following issue:
+            // https://github.com/rust-lang/rust/issues/51802
+            let mut local_len = SetLenOnDrop::new(&mut self.len);
+
             // drop any extra elements
-            while len < self.len {
-                // decrement len before the drop_in_place(), so a panic on Drop
-                // doesn't re-drop the just-failed value.
-                self.len -= 1;
-                let len = self.len;
-                ptr::drop_in_place(self.get_unchecked_mut(len));
+            for _ in len..current_len {
+                local_len.decrement_len(1);
+                ptr = ptr.offset(-1);
+                ptr::drop_in_place(ptr);
             }
         }
     }
@@ -1512,6 +1518,11 @@ impl<'a> SetLenOnDrop<'a> {
     fn increment_len(&mut self, increment: usize) {
         self.local_len += increment;
     }
+
+    #[inline]
+    fn decrement_len(&mut self, decrement: usize) {
+        self.local_len -= decrement;
+    }
 }
 
 impl<'a> Drop for SetLenOnDrop<'a> {

src/liballoc_system/lib.rs

@@ -174,7 +174,10 @@ mod platform {
         }
     }
 
-    #[cfg(any(target_os = "android", target_os = "redox", target_os = "solaris"))]
+    #[cfg(any(target_os = "android",
+              target_os = "hermit",
+              target_os = "redox",
+              target_os = "solaris"))]
     #[inline]
     unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
         // On android we currently target API level 9 which unfortunately
@@ -197,7 +200,10 @@ mod platform {
         libc::memalign(layout.align(), layout.size()) as *mut u8
     }
 
-    #[cfg(not(any(target_os = "android", target_os = "redox", target_os = "solaris")))]
+    #[cfg(not(any(target_os = "android",
+                  target_os = "hermit",
+                  target_os = "redox",
+                  target_os = "solaris")))]
     #[inline]
     unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
         let mut out = ptr::null_mut();