Auto merge of #87808 - JohnTitor:rollup-qqp79xs, r=JohnTitor

Rollup of 9 pull requests

Successful merges:

 - #87561 (thread set_name haiku implementation.)
 - #87715 (Add long error explanation for E0625)
 - #87727 (explicit_generic_args_with_impl_trait: fix min expected number of generics)
 - #87742 (Validate FFI-safety warnings on naked functions)
 - #87756 (Add back -Zno-profiler-runtime)
 - #87759 (Re-use std::sealed::Sealed in os/linux/process.)
 - #87760 (Promote `aarch64-apple-ios-sim` to Tier 2)
 - #87770 (permit drop impls with generic constants in where clauses)
 - #87780 (alloc: Use intra doc links for the reserve function)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_error_codes/src/error_codes.rs

@@ -359,6 +359,7 @@ E0621: include_str!("./error_codes/E0621.md"),
 E0622: include_str!("./error_codes/E0622.md"),
 E0623: include_str!("./error_codes/E0623.md"),
 E0624: include_str!("./error_codes/E0624.md"),
+E0625: include_str!("./error_codes/E0625.md"),
 E0626: include_str!("./error_codes/E0626.md"),
 E0627: include_str!("./error_codes/E0627.md"),
 E0628: include_str!("./error_codes/E0628.md"),
@@ -622,7 +623,6 @@ E0783: include_str!("./error_codes/E0783.md"),
 //  E0611, // merged into E0616
 //  E0612, // merged into E0609
 //  E0613, // Removed (merged with E0609)
-    E0625, // thread-local statics cannot be accessed at compile-time
 //  E0629, // missing 'feature' (rustc_const_unstable)
 //  E0630, // rustc_const_unstable attribute must be paired with stable/unstable
            // attribute

compiler/rustc_error_codes/src/error_codes/E0625.md

@@ -0,0 +1,28 @@
+A compile-time const variable is referring to a thread-local static variable.
+
+Erroneous code example:
+
+```compile_fail,E0625
+#![feature(thread_local)]
+
+#[thread_local]
+static X: usize = 12;
+
+const Y: usize = 2 * X;
+```
+
+Static and const variables can refer to other const variables but a const
+variable cannot refer to a thread-local static variable. In this example,
+`Y` cannot refer to `X`. To fix this, the value can be extracted as a const
+and then used:
+
+```
+#![feature(thread_local)]
+
+const C: usize = 12;
+
+#[thread_local]
+static X: usize = C;
+
+const Y: usize = 2 * C;
+```

compiler/rustc_interface/src/tests.rs

@@ -740,6 +740,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(new_llvm_pass_manager, Some(true));
     tracked!(no_generate_arange_section, true);
     tracked!(no_link, true);
+    tracked!(no_profiler_runtime, true);
     tracked!(osx_rpath_install_name, true);
     tracked!(panic_abort_tests, true);
     tracked!(plt, Some(true));
@@ -748,7 +749,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(print_fuel, Some("abc".to_string()));
     tracked!(profile, true);
     tracked!(profile_emit, Some(PathBuf::from("abc")));
-    tracked!(profiler_runtime, None);
+    tracked!(profiler_runtime, "abc".to_string());
     tracked!(relax_elf_relocations, Some(true));
     tracked!(relro_level, Some(RelroLevel::Full));
     tracked!(simulate_remapped_rust_src_base, Some(PathBuf::from("/rustc/abc")));

compiler/rustc_metadata/src/creader.rs

@@ -777,19 +777,17 @@ impl<'a> CrateLoader<'a> {
     }
 
     fn inject_profiler_runtime(&mut self, krate: &ast::Crate) {
-        let profiler_runtime = &self.sess.opts.debugging_opts.profiler_runtime;
-
-        if !(profiler_runtime.is_some()
-            && (self.sess.instrument_coverage()
+        if self.sess.opts.debugging_opts.no_profiler_runtime
+            || !(self.sess.instrument_coverage()
                 || self.sess.opts.debugging_opts.profile
-                || self.sess.opts.cg.profile_generate.enabled()))
+                || self.sess.opts.cg.profile_generate.enabled())
         {
             return;
         }
 
         info!("loading profiler");
 
-        let name = Symbol::intern(profiler_runtime.as_ref().unwrap());
+        let name = Symbol::intern(&self.sess.opts.debugging_opts.profiler_runtime);
         if name == sym::profiler_builtins && self.sess.contains_name(&krate.attrs, sym::no_core) {
             self.sess.err(
                 "`profiler_builtins` crate (required by compiler options) \

compiler/rustc_metadata/src/locator.rs

@@ -1103,8 +1103,8 @@ impl CrateError {
                         if sess.is_nightly_build() {
                             err.help("consider building the standard library from source with `cargo build -Zbuild-std`");
                         }
-                    } else if Some(crate_name)
-                        == sess.opts.debugging_opts.profiler_runtime.as_deref().map(Symbol::intern)
+                    } else if crate_name
+                        == Symbol::intern(&sess.opts.debugging_opts.profiler_runtime)
                     {
                         err.note(&"the compiler may have been built without the profiler runtime");
                     }

compiler/rustc_session/src/options.rs

@@ -1172,6 +1172,8 @@ options! {
         "compile without linking"),
     no_parallel_llvm: bool = (false, parse_no_flag, [UNTRACKED],
         "run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO)"),
+    no_profiler_runtime: bool = (false, parse_no_flag, [TRACKED],
+        "prevent automatic injection of the profiler_builtins crate"),
     normalize_docs: bool = (false, parse_bool, [TRACKED],
         "normalize associated items in rustdoc when generating documentation"),
     osx_rpath_install_name: bool = (false, parse_bool, [TRACKED],
@@ -1217,8 +1219,8 @@ options! {
     profile_emit: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "file path to emit profiling data at runtime when using 'profile' \
         (default based on relative source path)"),
-    profiler_runtime: Option<String> = (Some(String::from("profiler_builtins")), parse_opt_string, [TRACKED],
-        "name of the profiler runtime crate to automatically inject, or None to disable"),
+    profiler_runtime: String = (String::from("profiler_builtins"), parse_string, [TRACKED],
+        "name of the profiler runtime crate to automatically inject (default: `profiler_builtins`)"),
     query_dep_graph: bool = (false, parse_bool, [UNTRACKED],
         "enable queries of the dependency graph for regression testing (default: no)"),
     query_stats: bool = (false, parse_bool, [UNTRACKED],

compiler/rustc_typeck/src/astconv/generics.rs

@@ -613,7 +613,6 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 param_counts.consts + named_type_param_count
                     - default_counts.types
                     - default_counts.consts
-                    - synth_type_param_count
             };
             debug!("expected_min: {:?}", expected_min);
             debug!("arg_counts.lifetimes: {:?}", gen_args.num_lifetime_params());

compiler/rustc_typeck/src/check/dropck.rs

@@ -218,9 +218,9 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
 
         // This closure is a more robust way to check `Predicate` equality
         // than simple `==` checks (which were the previous implementation).
-        // It relies on `ty::relate` for `TraitPredicate` and `ProjectionPredicate`
-        // (which implement the Relate trait), while delegating on simple equality
-        // for the other `Predicate`.
+        // It relies on `ty::relate` for `TraitPredicate`, `ProjectionPredicate`,
+        // `ConstEvaluatable` and `TypeOutlives` (which implement the Relate trait),
+        // while delegating on simple equality for the other `Predicate`.
         // This implementation solves (Issue #59497) and (Issue #58311).
         // It is unclear to me at the moment whether the approach based on `relate`
         // could be extended easily also to the other `Predicate`.
@@ -235,6 +235,13 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
                 (ty::PredicateKind::Projection(a), ty::PredicateKind::Projection(b)) => {
                     relator.relate(predicate.rebind(a), p.rebind(b)).is_ok()
                 }
+                (
+                    ty::PredicateKind::ConstEvaluatable(def_a, substs_a),
+                    ty::PredicateKind::ConstEvaluatable(def_b, substs_b),
+                ) => tcx.try_unify_abstract_consts(((def_a, substs_a), (def_b, substs_b))),
+                (ty::PredicateKind::TypeOutlives(a), ty::PredicateKind::TypeOutlives(b)) => {
+                    relator.relate(predicate.rebind(a.0), p.rebind(b.0)).is_ok()
+                }
                 _ => predicate == p,
             }
         };

library/alloc/src/collections/vec_deque/mod.rs

@@ -697,7 +697,9 @@ impl<T, A: Allocator> VecDeque<T, A> {
     ///
     /// Note that the allocator may give the collection more space than it
     /// requests. Therefore, capacity can not be relied upon to be precisely
-    /// minimal. Prefer `reserve` if future insertions are expected.
+    /// minimal. Prefer [`reserve`] if future insertions are expected.
+    ///
+    /// [`reserve`]: VecDeque::reserve
     ///
     /// # Errors
     ///

library/alloc/src/string.rs

@@ -1035,7 +1035,9 @@ impl String {
     ///
     /// Note that the allocator may give the collection more space than it
     /// requests. Therefore, capacity can not be relied upon to be precisely
-    /// minimal. Prefer `reserve` if future insertions are expected.
+    /// minimal. Prefer [`reserve`] if future insertions are expected.
+    ///
+    /// [`reserve`]: String::reserve
     ///
     /// # Errors
     ///

library/alloc/src/vec/mod.rs

@@ -811,7 +811,9 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// Note that the allocator may give the collection more space than it
     /// requests. Therefore, capacity can not be relied upon to be precisely
-    /// minimal. Prefer `reserve` if future insertions are expected.
+    /// minimal. Prefer [`reserve`] if future insertions are expected.
+    ///
+    /// [`reserve`]: Vec::reserve
     ///
     /// # Panics
     ///
@@ -875,7 +877,9 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// Note that the allocator may give the collection more space than it
     /// requests. Therefore, capacity can not be relied upon to be precisely
-    /// minimal. Prefer `reserve` if future insertions are expected.
+    /// minimal. Prefer [`reserve`] if future insertions are expected.
+    ///
+    /// [`reserve`]: Vec::reserve
     ///
     /// # Errors
     ///

library/std/src/ffi/os_str.rs

@@ -271,7 +271,9 @@ impl OsString {
     ///
     /// Note that the allocator may give the collection more space than it
     /// requests. Therefore, capacity can not be relied upon to be precisely
-    /// minimal. Prefer reserve if future insertions are expected.
+    /// minimal. Prefer [`reserve`] if future insertions are expected.
+    ///
+    /// [`reserve`]: OsString::reserve
     ///
     /// # Examples
     ///

library/std/src/os/linux/process.rs

@@ -5,6 +5,7 @@
 use crate::io::Result;
 use crate::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
 use crate::process;
+use crate::sealed::Sealed;
 #[cfg(not(doc))]
 use crate::sys::fd::FileDesc;
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
@@ -84,15 +85,10 @@ impl IntoRawFd for PidFd {
     }
 }
 
-mod private_child_ext {
-    pub trait Sealed {}
-    impl Sealed for crate::process::Child {}
-}
-
 /// Os-specific extensions for [`Child`]
 ///
 /// [`Child`]: process::Child
-pub trait ChildExt: private_child_ext::Sealed {
+pub trait ChildExt: Sealed {
     /// Obtains a reference to the [`PidFd`] created for this [`Child`], if available.
     ///
     /// A pidfd will only be available if its creation was requested with
@@ -120,15 +116,10 @@ pub trait ChildExt: private_child_ext::Sealed {
     fn take_pidfd(&mut self) -> Result<PidFd>;
 }
 
-mod private_command_ext {
-    pub trait Sealed {}
-    impl Sealed for crate::process::Command {}
-}
-
 /// Os-specific extensions for [`Command`]
 ///
 /// [`Command`]: process::Command
-pub trait CommandExt: private_command_ext::Sealed {
+pub trait CommandExt: Sealed {
     /// Sets whether a [`PidFd`](struct@PidFd) should be created for the [`Child`]
     /// spawned by this [`Command`].
     /// By default, no pidfd will be created.

library/std/src/process.rs

@@ -205,6 +205,10 @@ pub struct Child {
     pub stderr: Option<ChildStderr>,
 }
 
+/// Allows extension traits within `std`.
+#[unstable(feature = "sealed", issue = "none")]
+impl crate::sealed::Sealed for Child {}
+
 impl AsInner<imp::Process> for Child {
     fn as_inner(&self) -> &imp::Process {
         &self.handle

library/std/src/sys/unix/thread.rs

@@ -164,16 +164,23 @@ impl Thread {
         }
     }
 
+    #[cfg(target_os = "haiku")]
+    pub fn set_name(name: &CStr) {
+        unsafe {
+            let thread_self = libc::find_thread(ptr::null_mut());
+            libc::rename_thread(thread_self, name.as_ptr());
+        }
+    }
+
     #[cfg(any(
         target_env = "newlib",
-        target_os = "haiku",
         target_os = "l4re",
         target_os = "emscripten",
         target_os = "redox",
         target_os = "vxworks"
     ))]
     pub fn set_name(_name: &CStr) {
-        // Newlib, Haiku, Emscripten, and VxWorks have no way to set a thread name.
+        // Newlib, Emscripten, and VxWorks have no way to set a thread name.
     }
 
     pub fn sleep(dur: Duration) {

src/doc/rustc/src/platform-support.md

@@ -165,6 +165,7 @@ target | std | notes
 `wasm32-unknown-unknown` | ✓ | WebAssembly
 `wasm32-wasi` | ✓ | WebAssembly with WASI
 `x86_64-apple-ios` | ✓ | 64-bit x86 iOS
+[`aarch64-apple-ios-sim`](platform-support/aarch64-apple-ios-sim.md) | ✓ |  | Apple iOS Simulator on ARM64
 `x86_64-fortanix-unknown-sgx` | ✓ | [Fortanix ABI] for 64-bit Intel SGX
 `x86_64-fuchsia` | ✓ | 64-bit Fuchsia
 `x86_64-linux-android` | ✓ | 64-bit x86 Android
@@ -196,7 +197,6 @@ host tools.
 target | std | host | notes
 -------|:---:|:----:|-------
 `aarch64-apple-ios-macabi` | ? |  | Apple Catalyst on ARM64
-[`aarch64-apple-ios-sim`](platform-support/aarch64-apple-ios-sim.md) | ✓ |  | Apple iOS Simulator on ARM64
 `aarch64-apple-tvos` | * |  | ARM64 tvOS
 `aarch64-unknown-freebsd` | ✓ | ✓ | ARM64 FreeBSD
 `aarch64-unknown-hermit` | ? |  |

src/doc/rustc/src/platform-support/aarch64-apple-ios-sim.md

@@ -1,6 +1,6 @@
 # aarch64-apple-ios-sim
 
-**Tier: 3**
+**Tier: 2**
 
 Apple iOS Simulator on ARM64.
 
@@ -39,17 +39,16 @@ Currently there is no support to run the rustc test suite for this target.
 
 *Note: Building for this target requires the corresponding iOS SDK, as provided by Xcode 12+.*
 
-If `rustc` has support for that target and the library artifacts are available,
-then Rust programs can be built for that target:
+From Rust Nightly 1.56.0 (2021-08-03) on the artifacts are shipped pre-compiled:
 
 ```text
-rustc --target aarch64-apple-ios-sim your-code.rs
+rustup target add aarch64-apple-ios-sim --toolchain nightly
 ```
 
-On Rust Nightly it is possible to build without the target artifacts available:
+Rust programs can be built for that target:
 
 ```text
-cargo build -Z build-std --target aarch64-apple-ios-sim
+rustc --target aarch64-apple-ios-sim your-code.rs
 ```
 
 There is no easy way to run simple programs in the iOS simulator.

src/test/ui/asm/naked-functions-ffi.rs

@@ -0,0 +1,12 @@
+// check-pass
+// only-x86_64
+#![feature(asm)]
+#![feature(naked_functions)]
+#![crate_type = "lib"]
+
+#[naked]
+pub extern "C" fn naked(p: char) -> u128 {
+    //~^ WARN uses type `char`
+    //~| WARN uses type `u128`
+    unsafe { asm!("", options(noreturn)); }
+}

src/test/ui/asm/naked-functions-ffi.stderr

@@ -0,0 +1,20 @@
+warning: `extern` fn uses type `char`, which is not FFI-safe
+  --> $DIR/naked-functions-ffi.rs:8:28
+   |
+LL | pub extern "C" fn naked(p: char) -> u128 {
+   |                            ^^^^ not FFI-safe
+   |
+   = note: `#[warn(improper_ctypes_definitions)]` on by default
+   = help: consider using `u32` or `libc::wchar_t` instead
+   = note: the `char` type has no C equivalent
+
+warning: `extern` fn uses type `u128`, which is not FFI-safe
+  --> $DIR/naked-functions-ffi.rs:8:37
+   |
+LL | pub extern "C" fn naked(p: char) -> u128 {
+   |                                     ^^^^ not FFI-safe
+   |
+   = note: 128-bit integers don't currently have a known stable ABI
+
+warning: 2 warnings emitted
+

src/test/ui/const-generics/const_evaluatable_checked/drop_impl.rs

@@ -0,0 +1,16 @@
+//check-pass
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+
+struct Foo<const N: usize>
+where
+    [(); N + 1]: ;
+
+impl<const N: usize> Drop for Foo<N>
+where
+    [(); N + 1]: ,
+{
+    fn drop(&mut self) {}
+}
+
+fn main() {}

src/test/ui/impl-trait/explicit-generic-args-with-impl-trait/explicit-generic-args-for-impl.stderr

@@ -1,12 +1,12 @@
-error[E0107]: this function takes at most 1 generic argument but 2 generic arguments were supplied
+error[E0107]: this function takes 1 generic argument but 2 generic arguments were supplied
   --> $DIR/explicit-generic-args-for-impl.rs:6:5
    |
 LL |     foo::<str, String>("".to_string());
    |     ^^^        ------ help: remove this generic argument
    |     |
-   |     expected at most 1 generic argument
+   |     expected 1 generic argument
    |
-note: function defined here, with at most 1 generic parameter: `T`
+note: function defined here, with 1 generic parameter: `T`
   --> $DIR/explicit-generic-args-for-impl.rs:3:4
    |
 LL | fn foo<T: ?Sized>(_f: impl AsRef<T>) {}