Auto merge of #52616 - kennytm:rollup, r=kennytm

Rollup of 11 pull requests

Successful merges:

 - #51807 (Deprecation of str::slice_unchecked(_mut))
 - #52051 (mem::swap the obvious way for types smaller than the SIMD optimization's block size)
 - #52465 (Add CI test harness for `thumb*` targets. [IRR-2018-embedded])
 - #52507 (Reword when `_` couldn't be inferred)
 - #52508 (Document that Unique::empty() and NonNull::dangling() aren't sentinel values)
 - #52521 (Fix links in rustdoc book.)
 - #52581 (Avoid using `#[macro_export]` for documenting builtin macros)
 - #52582 (Typo)
 - #52587 (Add missing backtick in UniversalRegions doc comment)
 - #52594 (Run the error index tool against the sysroot libdir)
 - #52615 (Added new lines to .gitignore.)

.gitignore

@@ -86,15 +86,18 @@ __pycache__/
 target/
 /test/
 /tmp/
+tags
+tags.*
 TAGS
-TAGS.emacs
-TAGS.vi
+TAGS.*
 \#*
 \#*\#
 config.mk
 config.stamp
 keywords.md
 lexer.ml
+mir_dump
+Session.vim
 src/etc/dl
 tmp.*.rs
 version.md

src/bootstrap/test.rs

@@ -966,7 +966,9 @@ impl Step for Compiletest {
             builder.ensure(compile::Rustc { compiler, target });
         }
 
-        builder.ensure(compile::Test { compiler, target });
+        if builder.no_std(target) != Some(true) {
+            builder.ensure(compile::Test { compiler, target });
+        }
         builder.ensure(native::TestHelpers { target });
         builder.ensure(RemoteCopyLibs { compiler, target });
 

src/bootstrap/tool.rs

@@ -275,7 +275,7 @@ pub fn prepare_tool_cargo(
 
 macro_rules! tool {
     ($($name:ident, $path:expr, $tool_name:expr, $mode:expr $(,llvm_tools = $llvm:expr)*;)+) => {
-        #[derive(Copy, Clone)]
+        #[derive(Copy, PartialEq, Eq, Clone)]
         pub enum Tool {
             $(
                 $name,
@@ -640,7 +640,7 @@ impl<'a> Builder<'a> {
     fn prepare_tool_cmd(&self, compiler: Compiler, tool: Tool, cmd: &mut Command) {
         let host = &compiler.host;
         let mut lib_paths: Vec<PathBuf> = vec![
-            if compiler.stage == 0 {
+            if compiler.stage == 0 && tool != Tool::ErrorIndex {
                 self.build.rustc_snapshot_libdir()
             } else {
                 PathBuf::from(&self.sysroot_libdir(compiler, compiler.host))

src/ci/docker/dist-various-1/Dockerfile

@@ -80,6 +80,11 @@ RUN \
   echo "# a" >> /usr/local/mips-linux-musl/bin/mips-openwrt-linux-musl-wrapper.sh && \
   echo "# b" >> /usr/local/mipsel-linux-musl/bin/mipsel-openwrt-linux-musl-wrapper.sh
 
+ENV RUN_MAKE_TARGETS=thumbv6m-none-eabi
+ENV RUN_MAKE_TARGETS=$RUN_MAKE_TARGETS,thumbv7m-none-eabi
+ENV RUN_MAKE_TARGETS=$RUN_MAKE_TARGETS,thumbv7em-none-eabi
+ENV RUN_MAKE_TARGETS=$RUN_MAKE_TARGETS,thumbv7em-none-eabihf
+
 ENV TARGETS=asmjs-unknown-emscripten
 ENV TARGETS=$TARGETS,wasm32-unknown-emscripten
 ENV TARGETS=$TARGETS,x86_64-rumprun-netbsd
@@ -120,7 +125,9 @@ ENV RUST_CONFIGURE_ARGS \
       --enable-emscripten \
       --disable-docs
 
-ENV SCRIPT python2.7 ../x.py dist --target $TARGETS
+ENV SCRIPT \ 
+      python2.7 ../x.py test --target $RUN_MAKE_TARGETS src/test/run-make && \
+      python2.7 ../x.py dist --target $TARGETS
 
 # sccache
 COPY scripts/sccache.sh /scripts/

src/doc/rustdoc/src/passes.md

@@ -5,8 +5,8 @@ Rustdoc has a concept called "passes". These are transformations that
 
 In addition to the passes below, check out the docs for these flags:
 
-* [`--passes`](command-line-arguments.html#--passes-add-more-rustdoc-passes)
-* [`--no-defaults`](command-line-arguments.html#--no-defaults-dont-run-default-passes)
+* [`--passes`](command-line-arguments.html#a--passes-add-more-rustdoc-passes)
+* [`--no-defaults`](command-line-arguments.html#a--no-defaults-dont-run-default-passes)
 
 ## Default passes
 

src/liballoc/str.rs

@@ -268,11 +268,11 @@ impl str {
         let mut result = String::new();
         let mut last_end = 0;
         for (start, part) in self.match_indices(from) {
-            result.push_str(unsafe { self.slice_unchecked(last_end, start) });
+            result.push_str(unsafe { self.get_unchecked(last_end..start) });
             result.push_str(to);
             last_end = start + part.len();
         }
-        result.push_str(unsafe { self.slice_unchecked(last_end, self.len()) });
+        result.push_str(unsafe { self.get_unchecked(last_end..self.len()) });
         result
     }
 
@@ -309,11 +309,11 @@ impl str {
         let mut result = String::with_capacity(32);
         let mut last_end = 0;
         for (start, part) in self.match_indices(pat).take(count) {
-            result.push_str(unsafe { self.slice_unchecked(last_end, start) });
+            result.push_str(unsafe { self.get_unchecked(last_end..start) });
             result.push_str(to);
             last_end = start + part.len();
         }
-        result.push_str(unsafe { self.slice_unchecked(last_end, self.len()) });
+        result.push_str(unsafe { self.get_unchecked(last_end..self.len()) });
         result
     }
 

src/liballoc/string.rs

@@ -1222,7 +1222,7 @@ impl String {
 
         while idx < len {
             let ch = unsafe {
-                self.slice_unchecked(idx, len).chars().next().unwrap()
+                self.get_unchecked(idx..len).chars().next().unwrap()
             };
             let ch_len = ch.len_utf8();
 

src/liballoc/tests/str.rs

@@ -177,9 +177,9 @@ fn test_join_for_different_lengths_with_long_separator() {
 
 #[test]
 fn test_unsafe_slice() {
-    assert_eq!("ab", unsafe {"abc".slice_unchecked(0, 2)});
-    assert_eq!("bc", unsafe {"abc".slice_unchecked(1, 3)});
-    assert_eq!("", unsafe {"abc".slice_unchecked(1, 1)});
+    assert_eq!("ab", unsafe {"abc".get_unchecked(0..2)});
+    assert_eq!("bc", unsafe {"abc".get_unchecked(1..3)});
+    assert_eq!("", unsafe {"abc".get_unchecked(1..1)});
     fn a_million_letter_a() -> String {
         let mut i = 0;
         let mut rs = String::new();
@@ -200,7 +200,7 @@ fn test_unsafe_slice() {
     }
     let letters = a_million_letter_a();
     assert_eq!(half_a_million_letter_a(),
-        unsafe { letters.slice_unchecked(0, 500000)});
+        unsafe { letters.get_unchecked(0..500000)});
 }
 
 #[test]

src/libcore/macros.rs

@@ -543,6 +543,7 @@ macro_rules! unimplemented {
 /// into libsyntax itself.
 ///
 /// For more information, see documentation for `std`'s macros.
+#[cfg(dox)]
 mod builtin {
 
     /// Unconditionally causes compilation to fail with the given error message when encountered.
@@ -551,8 +552,7 @@ mod builtin {
     ///
     /// [`std::compile_error!`]: ../std/macro.compile_error.html
     #[stable(feature = "compile_error_macro", since = "1.20.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! compile_error {
         ($msg:expr) => ({ /* compiler built-in */ });
         ($msg:expr,) => ({ /* compiler built-in */ });
@@ -564,8 +564,7 @@ mod builtin {
     ///
     /// [`std::format_args!`]: ../std/macro.format_args.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! format_args {
         ($fmt:expr) => ({ /* compiler built-in */ });
         ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ });
@@ -577,8 +576,7 @@ mod builtin {
     ///
     /// [`std::env!`]: ../std/macro.env.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! env {
         ($name:expr) => ({ /* compiler built-in */ });
         ($name:expr,) => ({ /* compiler built-in */ });
@@ -590,8 +588,7 @@ mod builtin {
     ///
     /// [`std::option_env!`]: ../std/macro.option_env.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! option_env {
         ($name:expr) => ({ /* compiler built-in */ });
         ($name:expr,) => ({ /* compiler built-in */ });
@@ -603,8 +600,7 @@ mod builtin {
     ///
     /// [`std::concat_idents!`]: ../std/macro.concat_idents.html
     #[unstable(feature = "concat_idents_macro", issue = "29599")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! concat_idents {
         ($($e:ident),+) => ({ /* compiler built-in */ });
         ($($e:ident,)+) => ({ /* compiler built-in */ });
@@ -616,8 +612,7 @@ mod builtin {
     ///
     /// [`std::concat!`]: ../std/macro.concat.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! concat {
         ($($e:expr),*) => ({ /* compiler built-in */ });
         ($($e:expr,)*) => ({ /* compiler built-in */ });
@@ -629,8 +624,7 @@ mod builtin {
     ///
     /// [`std::line!`]: ../std/macro.line.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! line { () => ({ /* compiler built-in */ }) }
 
     /// A macro which expands to the column number on which it was invoked.
@@ -639,8 +633,7 @@ mod builtin {
     ///
     /// [`std::column!`]: ../std/macro.column.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! column { () => ({ /* compiler built-in */ }) }
 
     /// A macro which expands to the file name from which it was invoked.
@@ -649,8 +642,7 @@ mod builtin {
     ///
     /// [`std::file!`]: ../std/macro.file.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! file { () => ({ /* compiler built-in */ }) }
 
     /// A macro which stringifies its arguments.
@@ -659,8 +651,7 @@ mod builtin {
     ///
     /// [`std::stringify!`]: ../std/macro.stringify.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! stringify { ($($t:tt)*) => ({ /* compiler built-in */ }) }
 
     /// Includes a utf8-encoded file as a string.
@@ -669,8 +660,7 @@ mod builtin {
     ///
     /// [`std::include_str!`]: ../std/macro.include_str.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! include_str {
         ($file:expr) => ({ /* compiler built-in */ });
         ($file:expr,) => ({ /* compiler built-in */ });
@@ -682,8 +672,7 @@ mod builtin {
     ///
     /// [`std::include_bytes!`]: ../std/macro.include_bytes.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! include_bytes {
         ($file:expr) => ({ /* compiler built-in */ });
         ($file:expr,) => ({ /* compiler built-in */ });
@@ -695,8 +684,7 @@ mod builtin {
     ///
     /// [`std::module_path!`]: ../std/macro.module_path.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! module_path { () => ({ /* compiler built-in */ }) }
 
     /// Boolean evaluation of configuration flags, at compile-time.
@@ -705,8 +693,7 @@ mod builtin {
     ///
     /// [`std::cfg!`]: ../std/macro.cfg.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! cfg { ($($cfg:tt)*) => ({ /* compiler built-in */ }) }
 
     /// Parse a file as an expression or an item according to the context.
@@ -715,8 +702,7 @@ mod builtin {
     ///
     /// [`std::include!`]: ../std/macro.include.html
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[macro_export]
-    #[cfg(dox)]
+    #[rustc_doc_only_macro]
     macro_rules! include {
         ($file:expr) => ({ /* compiler built-in */ });
         ($file:expr,) => ({ /* compiler built-in */ });
@@ -727,9 +713,8 @@ mod builtin {
     /// For more information, see the documentation for [`std::assert!`].
     ///
     /// [`std::assert!`]: ../std/macro.assert.html
-    #[macro_export]
+    #[rustc_doc_only_macro]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg(dox)]
     macro_rules! assert {
         ($cond:expr) => ({ /* compiler built-in */ });
         ($cond:expr,) => ({ /* compiler built-in */ });

src/libcore/mem.rs

@@ -638,7 +638,7 @@ pub unsafe fn uninitialized<T>() -> T {
 #[stable(feature = "rust1", since = "1.0.0")]
 pub fn swap<T>(x: &mut T, y: &mut T) {
     unsafe {
-        ptr::swap_nonoverlapping(x, y, 1);
+        ptr::swap_nonoverlapping_one(x, y);
     }
 }
 

src/libcore/ptr.rs

@@ -187,6 +187,19 @@ pub unsafe fn swap_nonoverlapping<T>(x: *mut T, y: *mut T, count: usize) {
     swap_nonoverlapping_bytes(x, y, len)
 }
 
+#[inline]
+pub(crate) unsafe fn swap_nonoverlapping_one<T>(x: *mut T, y: *mut T) {
+    // For types smaller than the block optimization below,
+    // just swap directly to avoid pessimizing codegen.
+    if mem::size_of::<T>() < 32 {
+        let z = read(x);
+        copy_nonoverlapping(y, x, 1);
+        write(y, z);
+    } else {
+        swap_nonoverlapping(x, y, 1);
+    }
+}
+
 #[inline]
 unsafe fn swap_nonoverlapping_bytes(x: *mut u8, y: *mut u8, len: usize) {
     // The approach here is to utilize simd to swap x & y efficiently. Testing reveals
@@ -2703,6 +2716,11 @@ impl<T: Sized> Unique<T> {
     ///
     /// This is useful for initializing types which lazily allocate, like
     /// `Vec::new` does.
+    ///
+    /// Note that the pointer value may potentially represent a valid pointer to
+    /// a `T`, which means this must not be used as a "not yet initialized"
+    /// sentinel value. Types that lazily allocate must track initialization by
+    /// some other means.
     // FIXME: rename to dangling() to match NonNull?
     pub const fn empty() -> Self {
         unsafe {
@@ -2834,6 +2852,11 @@ impl<T: Sized> NonNull<T> {
     ///
     /// This is useful for initializing types which lazily allocate, like
     /// `Vec::new` does.
+    ///
+    /// Note that the pointer value may potentially represent a valid pointer to
+    /// a `T`, which means this must not be used as a "not yet initialized"
+    /// sentinel value. Types that lazily allocate must track initialization by
+    /// some other means.
     #[stable(feature = "nonnull", since = "1.25.0")]
     pub fn dangling() -> Self {
         unsafe {