Auto merge of #70072 - Centril:rollup-722hooh, r=Centril

Rollup of 7 pull requests

Successful merges:

 - #68746 (Make macro metavars respect (non-)hygiene)
 - #69688 (Move tidy check to mingw-check)
 - #69735 (bootstrap: Use hash to determine if sanitizers needs to be rebuilt)
 - #69922 (implement zeroed and uninitialized with MaybeUninit)
 - #69956 (Ensure HAS_FREE_LOCAL_NAMES is set for ReFree)
 - #70061 (Cosmetic fixes in documentation)
 - #70064 (Update books)

Failed merges:

r? @ghost

Author: bors

src/bootstrap/native.rs

@@ -11,6 +11,7 @@
 use std::env;
 use std::ffi::OsString;
 use std::fs::{self, File};
+use std::io;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
@@ -54,7 +55,6 @@ impl Step for Llvm {
             }
         }
 
-        let llvm_info = &builder.in_tree_llvm_info;
         let root = "src/llvm-project/llvm";
         let out_dir = builder.llvm_out(target);
         let mut llvm_config_ret_dir = builder.llvm_out(builder.config.build);
@@ -65,40 +65,35 @@ impl Step for Llvm {
 
         let build_llvm_config =
             llvm_config_ret_dir.join(exe("llvm-config", &*builder.config.build));
-        let done_stamp = out_dir.join("llvm-finished-building");
 
-        if done_stamp.exists() {
-            if builder.config.llvm_skip_rebuild {
-                builder.info(
-                    "Warning: \
-                    Using a potentially stale build of LLVM; \
-                    This may not behave well.",
-                );
-                return build_llvm_config;
-            }
+        let stamp = out_dir.join("llvm-finished-building");
+        let stamp = HashStamp::new(stamp, builder.in_tree_llvm_info.sha());
 
-            if let Some(llvm_commit) = llvm_info.sha() {
-                let done_contents = t!(fs::read(&done_stamp));
+        if builder.config.llvm_skip_rebuild && stamp.path.exists() {
+            builder.info(
+                "Warning: \
+                Using a potentially stale build of LLVM; \
+                This may not behave well.",
+            );
+            return build_llvm_config;
+        }
 
-                // If LLVM was already built previously and the submodule's commit didn't change
-                // from the previous build, then no action is required.
-                if done_contents == llvm_commit.as_bytes() {
-                    return build_llvm_config;
-                }
-            } else {
+        if stamp.is_done() {
+            if stamp.hash.is_none() {
                 builder.info(
                     "Could not determine the LLVM submodule commit hash. \
                      Assuming that an LLVM rebuild is not necessary.",
                 );
                 builder.info(&format!(
                     "To force LLVM to rebuild, remove the file `{}`",
-                    done_stamp.display()
+                    stamp.path.display()
                 ));
-                return build_llvm_config;
             }
+            return build_llvm_config;
         }
 
         builder.info(&format!("Building LLVM for {}", target));
+        t!(stamp.remove());
         let _time = util::timeit(&builder);
         t!(fs::create_dir_all(&out_dir));
 
@@ -271,7 +266,7 @@ impl Step for Llvm {
 
         cfg.build();
 
-        t!(fs::write(&done_stamp, llvm_info.sha().unwrap_or("")));
+        t!(stamp.write());
 
         build_llvm_config
     }
@@ -584,17 +579,21 @@ impl Step for Sanitizers {
             return runtimes;
         }
 
-        let done_stamp = out_dir.join("sanitizers-finished-building");
-        if done_stamp.exists() {
-            builder.info(&format!(
-                "Assuming that sanitizers rebuild is not necessary. \
-                To force a rebuild, remove the file `{}`",
-                done_stamp.display()
-            ));
+        let stamp = out_dir.join("sanitizers-finished-building");
+        let stamp = HashStamp::new(stamp, builder.in_tree_llvm_info.sha());
+
+        if stamp.is_done() {
+            if stamp.hash.is_none() {
+                builder.info(&format!(
+                    "Rebuild sanitizers by removing the file `{}`",
+                    stamp.path.display()
+                ));
+            }
             return runtimes;
         }
 
         builder.info(&format!("Building sanitizers for {}", self.target));
+        t!(stamp.remove());
         let _time = util::timeit(&builder);
 
         let mut cfg = cmake::Config::new(&compiler_rt_dir);
@@ -623,8 +622,7 @@ impl Step for Sanitizers {
             cfg.build_target(&runtime.cmake_target);
             cfg.build();
         }
-
-        t!(fs::write(&done_stamp, b""));
+        t!(stamp.write());
 
         runtimes
     }
@@ -689,3 +687,41 @@ fn supported_sanitizers(
     }
     result
 }
+
+struct HashStamp {
+    path: PathBuf,
+    hash: Option<Vec<u8>>,
+}
+
+impl HashStamp {
+    fn new(path: PathBuf, hash: Option<&str>) -> Self {
+        HashStamp { path, hash: hash.map(|s| s.as_bytes().to_owned()) }
+    }
+
+    fn is_done(&self) -> bool {
+        match fs::read(&self.path) {
+            Ok(h) => self.hash.as_deref().unwrap_or(b"") == h.as_slice(),
+            Err(e) if e.kind() == io::ErrorKind::NotFound => false,
+            Err(e) => {
+                panic!("failed to read stamp file `{}`: {}", self.path.display(), e);
+            }
+        }
+    }
+
+    fn remove(&self) -> io::Result<()> {
+        match fs::remove_file(&self.path) {
+            Ok(()) => Ok(()),
+            Err(e) => {
+                if e.kind() == io::ErrorKind::NotFound {
+                    Ok(())
+                } else {
+                    Err(e)
+                }
+            }
+        }
+    }
+
+    fn write(&self) -> io::Result<()> {
+        fs::write(&self.path, self.hash.as_deref().unwrap_or(b""))
+    }
+}

src/ci/docker/mingw-check/Dockerfile

@@ -25,4 +25,5 @@ ENV RUN_CHECK_WITH_PARALLEL_QUERIES 1
 ENV SCRIPT python2.7 ../x.py check --target=i686-pc-windows-gnu --host=i686-pc-windows-gnu && \
            python2.7 ../x.py build --stage 0 src/tools/build-manifest && \
            python2.7 ../x.py test --stage 0 src/tools/compiletest && \
+           python2.7 ../x.py test src/tools/tidy && \
            /scripts/validate-toolstate.sh

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

@@ -29,7 +29,7 @@ ENV RUST_CONFIGURE_ARGS \
       --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
+ENV SCRIPT python2.7 ../x.py test --exclude src/tools/tidy && python2.7 ../x.py test src/tools/tidy
 
 # The purpose of this container isn't to test with debug assertions and
 # this is run on all PRs, so let's get speedier builds by disabling these extra

src/doc/embedded-book

@@ -1027,46 +1027,8 @@ extern "rust-intrinsic" {
     #[rustc_const_unstable(feature = "const_caller_location", issue = "47809")]
     pub fn caller_location() -> &'static crate::panic::Location<'static>;
 
-    /// Creates a value initialized to zero.
-    ///
-    /// `init` is unsafe because it returns a zeroed-out datum,
-    /// which is unsafe unless `T` is `Copy`. Also, even if T is
-    /// `Copy`, an all-zero value may not correspond to any legitimate
-    /// state for the type in question.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`std::mem::zeroed`](../../std/mem/fn.zeroed.html).
-    #[unstable(
-        feature = "core_intrinsics",
-        reason = "intrinsics are unlikely to ever be stabilized, instead \
-                         they should be used through stabilized interfaces \
-                         in the rest of the standard library",
-        issue = "none"
-    )]
-    #[rustc_deprecated(reason = "superseded by MaybeUninit, removal planned", since = "1.38.0")]
-    pub fn init<T>() -> T;
-
-    /// Creates an uninitialized value.
-    ///
-    /// `uninit` is unsafe because there is no guarantee of what its
-    /// contents are. In particular its drop-flag may be set to any
-    /// state, which means it may claim either dropped or
-    /// undropped. In the general case one must use `ptr::write` to
-    /// initialize memory previous set to the result of `uninit`.
-    ///
-    /// The stabilized version of this intrinsic is
-    /// [`std::mem::MaybeUninit`](../../std/mem/union.MaybeUninit.html).
-    #[unstable(
-        feature = "core_intrinsics",
-        reason = "intrinsics are unlikely to ever be stabilized, instead \
-                         they should be used through stabilized interfaces \
-                         in the rest of the standard library",
-        issue = "none"
-    )]
-    #[rustc_deprecated(reason = "superseded by MaybeUninit, removal planned", since = "1.38.0")]
-    pub fn uninit<T>() -> T;
-
     /// Moves a value out of scope without running drop glue.
+    /// This exists solely for `mem::forget_unsized`; normal `forget` uses `ManuallyDrop` instead.
     pub fn forget<T: ?Sized>(_: T);
 
     /// Reinterprets the bits of a value of one type as another type.

src/doc/reference

@@ -490,7 +490,7 @@ pub const fn needs_drop<T>() -> bool {
 ///
 /// let _x: &i32 = unsafe { mem::zeroed() }; // Undefined behavior!
 /// ```
-#[inline]
+#[inline(always)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated_in_future)]
 #[allow(deprecated)]
@@ -500,7 +500,7 @@ pub unsafe fn zeroed<T>() -> T {
     intrinsics::assert_zero_valid::<T>();
     #[cfg(bootstrap)]
     intrinsics::panic_if_uninhabited::<T>();
-    intrinsics::init()
+    MaybeUninit::zeroed().assume_init()
 }
 
 /// Bypasses Rust's normal memory-initialization checks by pretending to
@@ -525,7 +525,7 @@ pub unsafe fn zeroed<T>() -> T {
 /// [uninit]: union.MaybeUninit.html#method.uninit
 /// [assume_init]: union.MaybeUninit.html#method.assume_init
 /// [inv]: union.MaybeUninit.html#initialization-invariant
-#[inline]
+#[inline(always)]
 #[rustc_deprecated(since = "1.39.0", reason = "use `mem::MaybeUninit` instead")]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated_in_future)]
@@ -536,7 +536,7 @@ pub unsafe fn uninitialized<T>() -> T {
     intrinsics::assert_uninit_valid::<T>();
     #[cfg(bootstrap)]
     intrinsics::panic_if_uninhabited::<T>();
-    intrinsics::uninit()
+    MaybeUninit::uninit().assume_init()
 }
 
 /// Swaps the values at two mutable locations, without deinitializing either one.

src/doc/rust-by-example

@@ -554,24 +554,26 @@ bitflags! {
         /// Does this have [ConstKind::Placeholder]?
         const HAS_CT_PLACEHOLDER        = 1 << 8;
 
+        /// `true` if there are "names" of regions and so forth
+        /// that are local to a particular fn/inferctxt
+        const HAS_FREE_LOCAL_REGIONS    = 1 << 9;
+
         /// `true` if there are "names" of types and regions and so forth
         /// that are local to a particular fn
         const HAS_FREE_LOCAL_NAMES      = TypeFlags::HAS_TY_PARAM.bits
-                                        | TypeFlags::HAS_RE_PARAM.bits
                                         | TypeFlags::HAS_CT_PARAM.bits
                                         | TypeFlags::HAS_TY_INFER.bits
-                                        | TypeFlags::HAS_RE_INFER.bits
                                         | TypeFlags::HAS_CT_INFER.bits
                                         | TypeFlags::HAS_TY_PLACEHOLDER.bits
-                                        | TypeFlags::HAS_RE_PLACEHOLDER.bits
-                                        | TypeFlags::HAS_CT_PLACEHOLDER.bits;
+                                        | TypeFlags::HAS_CT_PLACEHOLDER.bits
+                                        | TypeFlags::HAS_FREE_LOCAL_REGIONS.bits;
 
         /// Does this have [Projection] or [UnnormalizedProjection]?
-        const HAS_TY_PROJECTION         = 1 << 9;
+        const HAS_TY_PROJECTION         = 1 << 10;
         /// Does this have [Opaque]?
-        const HAS_TY_OPAQUE             = 1 << 10;
+        const HAS_TY_OPAQUE             = 1 << 11;
         /// Does this have [ConstKind::Unevaluated]?
-        const HAS_CT_PROJECTION         = 1 << 11;
+        const HAS_CT_PROJECTION         = 1 << 12;
 
         /// Could this type be normalized further?
         const HAS_PROJECTION            = TypeFlags::HAS_TY_PROJECTION.bits
@@ -580,21 +582,21 @@ bitflags! {
 
         /// Present if the type belongs in a local type context.
         /// Set for placeholders and inference variables that are not "Fresh".
-        const KEEP_IN_LOCAL_TCX         = 1 << 12;
+        const KEEP_IN_LOCAL_TCX         = 1 << 13;
 
         /// Is an error type reachable?
-        const HAS_TY_ERR                = 1 << 13;
+        const HAS_TY_ERR                = 1 << 14;
 
         /// Does this have any region that "appears free" in the type?
         /// Basically anything but [ReLateBound] and [ReErased].
-        const HAS_FREE_REGIONS          = 1 << 14;
+        const HAS_FREE_REGIONS          = 1 << 15;
 
         /// Does this have any [ReLateBound] regions? Used to check
         /// if a global bound is safe to evaluate.
-        const HAS_RE_LATE_BOUND         = 1 << 15;
+        const HAS_RE_LATE_BOUND         = 1 << 16;
 
         /// Does this have any [ReErased] regions?
-        const HAS_RE_ERASED             = 1 << 16;
+        const HAS_RE_ERASED             = 1 << 17;
 
         /// Flags representing the nominal content of a type,
         /// computed by FlagsComputation. If you add a new nominal
@@ -608,6 +610,7 @@ bitflags! {
                                         | TypeFlags::HAS_TY_PLACEHOLDER.bits
                                         | TypeFlags::HAS_RE_PLACEHOLDER.bits
                                         | TypeFlags::HAS_CT_PLACEHOLDER.bits
+                                        | TypeFlags::HAS_FREE_LOCAL_REGIONS.bits
                                         | TypeFlags::HAS_TY_PROJECTION.bits
                                         | TypeFlags::HAS_TY_OPAQUE.bits
                                         | TypeFlags::HAS_CT_PROJECTION.bits

src/libcore/intrinsics.rs

@@ -1743,42 +1743,42 @@ impl RegionKind {
         }
     }
 
-    pub fn keep_in_local_tcx(&self) -> bool {
-        if let ty::ReVar(..) = self { true } else { false }
-    }
-
     pub fn type_flags(&self) -> TypeFlags {
         let mut flags = TypeFlags::empty();
 
-        if self.keep_in_local_tcx() {
-            flags = flags | TypeFlags::KEEP_IN_LOCAL_TCX;
-        }
-
         match *self {
             ty::ReVar(..) => {
                 flags = flags | TypeFlags::HAS_FREE_REGIONS;
+                flags = flags | TypeFlags::HAS_FREE_LOCAL_REGIONS;
                 flags = flags | TypeFlags::HAS_RE_INFER;
+                flags = flags | TypeFlags::KEEP_IN_LOCAL_TCX;
             }
             ty::RePlaceholder(..) => {
                 flags = flags | TypeFlags::HAS_FREE_REGIONS;
+                flags = flags | TypeFlags::HAS_FREE_LOCAL_REGIONS;
                 flags = flags | TypeFlags::HAS_RE_PLACEHOLDER;
             }
-            ty::ReLateBound(..) => {
-                flags = flags | TypeFlags::HAS_RE_LATE_BOUND;
-            }
             ty::ReEarlyBound(..) => {
                 flags = flags | TypeFlags::HAS_FREE_REGIONS;
+                flags = flags | TypeFlags::HAS_FREE_LOCAL_REGIONS;
                 flags = flags | TypeFlags::HAS_RE_PARAM;
             }
-            ty::ReEmpty(_) | ty::ReStatic | ty::ReFree { .. } | ty::ReScope { .. } => {
+            ty::ReFree { .. } | ty::ReScope { .. } => {
                 flags = flags | TypeFlags::HAS_FREE_REGIONS;
+                flags = flags | TypeFlags::HAS_FREE_LOCAL_REGIONS;
             }
-            ty::ReErased => {
-                flags = flags | TypeFlags::HAS_RE_ERASED;
+            ty::ReEmpty(_) | ty::ReStatic => {
+                flags = flags | TypeFlags::HAS_FREE_REGIONS;
             }
             ty::ReClosureBound(..) => {
                 flags = flags | TypeFlags::HAS_FREE_REGIONS;
             }
+            ty::ReLateBound(..) => {
+                flags = flags | TypeFlags::HAS_RE_LATE_BOUND;
+            }
+            ty::ReErased => {
+                flags = flags | TypeFlags::HAS_RE_ERASED;
+            }
         }
 
         debug!("type_flags({:?}) = {:?}", self, flags);