Merge from rustc

8 files changed, 92 insertions, 69 deletions

diff --git a/src/doc/rustc-dev-guide/src/tests/minicore.md b/src/doc/rustc-dev-guide/src/tests/minicore.md
index e4853b6d40e..507b259e027 100644
--- a/src/doc/rustc-dev-guide/src/tests/minicore.md
+++ b/src/doc/rustc-dev-guide/src/tests/minicore.md
@@ -6,25 +6,37 @@
 ui/codegen/assembly test suites. It provides `core` stubs for tests that need to
 build for cross-compiled targets but do not need/want to run.
 
+<div class="warning">
+Please note that [`minicore`] is only intended for `core` items, and explicitly
+**not** `std` or `alloc` items because `core` items are applicable to a wider
+range of tests.
+</div>
+
 A test can use [`minicore`] by specifying the `//@ add-core-stubs` directive.
 Then, mark the test with `#![feature(no_core)]` + `#![no_std]` + `#![no_core]`.
 Due to Edition 2015 extern prelude rules, you will probably need to declare
 `minicore` as an extern crate.
 
+## Implied compiler flags
+
 Due to the `no_std` + `no_core` nature of these tests, `//@ add-core-stubs`
 implies and requires that the test will be built with `-C panic=abort`.
-Unwinding panics are not supported.
+**Unwinding panics are not supported.**
+
+Tests will also be built with `-C force-unwind-tables=yes` to preserve CFI
+directives in assembly tests.
+
+TL;DR: `//@ add-core-stubs` implies two compiler flags:
+
+1. `-C panic=abort`
+2. `-C force-unwind-tables=yes`
+
+## Adding more `core` stubs
 
 If you find a `core` item to be missing from the [`minicore`] stub, consider
 adding it to the test auxiliary if it's likely to be used or is already needed
 by more than one test.
 
-<div class="warning">
-Please note that [`minicore`] is only intended for `core` items, and explicitly
-**not** `std` or `alloc` items because `core` items are applicable to a wider
-range of tests.
-</div>
-
 ## Example codegen test that uses `minicore`
 
 ```rust,no_run
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 9870e5011eb..50c7ae3ef8d 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -34,7 +34,7 @@ target | notes
 -------|-------
 [`aarch64-apple-darwin`](platform-support/apple-darwin.md) | ARM64 macOS (11.0+, Big Sur+)
 `aarch64-unknown-linux-gnu` | ARM64 Linux (kernel 4.1, glibc 2.17+)
-`i686-pc-windows-msvc` | 32-bit MSVC (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI]
+`i686-pc-windows-msvc` | 32-bit MSVC (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 `i686-unknown-linux-gnu` | 32-bit Linux (kernel 3.2+, glibc 2.17+, Pentium 4) [^x86_32-floats-return-ABI]
 [`x86_64-apple-darwin`](platform-support/apple-darwin.md) | 64-bit macOS (10.12+, Sierra+)
 [`x86_64-pc-windows-gnu`](platform-support/windows-gnu.md) | 64-bit MinGW (Windows 10+, Windows Server 2016+)
@@ -43,6 +43,8 @@ target | notes
 
 [^x86_32-floats-return-ABI]: Due to limitations of the C ABI, floating-point support on `i686` targets is non-compliant: floating-point return values are passed via an x87 register, so NaN payload bits can be lost. Functions with the default Rust ABI are not affected. See [issue #115567][x86-32-float-return-issue].
 
+[^win32-msvc-alignment]: Due to non-standard behavior of MSVC, native C code on this target can cause types with an alignment of more than 4 bytes to be incorrectly aligned to only 4 bytes (this affects, e.g., `u64` and `i64`). Rust applies some mitigations to reduce the impact of this issue, but this can still cause unsoundness due to unsafe code that (correctly) assumes that references are always properly aligned. See [issue #112480](https://github.com/rust-lang/rust/issues/112480).
+
 [77071]: https://github.com/rust-lang/rust/issues/77071
 [x86-32-float-return-issue]: https://github.com/rust-lang/rust/issues/115567
 
@@ -95,7 +97,7 @@ target | notes
 [`armv7-unknown-linux-ohos`](platform-support/openharmony.md) | Armv7-A OpenHarmony
 [`loongarch64-unknown-linux-gnu`](platform-support/loongarch-linux.md) | LoongArch64 Linux, LP64D ABI (kernel 5.19, glibc 2.36)
 [`loongarch64-unknown-linux-musl`](platform-support/loongarch-linux.md) | LoongArch64 Linux, LP64D ABI (kernel 5.19, musl 1.2.5)
-[`i686-pc-windows-gnu`](platform-support/windows-gnu.md) | 32-bit MinGW (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI]
+[`i686-pc-windows-gnu`](platform-support/windows-gnu.md) | 32-bit MinGW (Windows 10+, Windows Server 2016+, Pentium 4) [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 `powerpc-unknown-linux-gnu` | PowerPC Linux (kernel 3.2, glibc 2.17)
 `powerpc64-unknown-linux-gnu` | PPC64 Linux (kernel 3.2, glibc 2.17)
 [`powerpc64le-unknown-linux-gnu`](platform-support/powerpc64le-unknown-linux-gnu.md) | PPC64LE Linux (kernel 3.10, glibc 2.17)
@@ -169,7 +171,7 @@ target | std | notes
 [`i686-pc-windows-gnullvm`](platform-support/windows-gnullvm.md) | ✓ | 32-bit x86 MinGW (Windows 10+, Pentium 4), LLVM ABI [^x86_32-floats-return-ABI]
 [`i686-unknown-freebsd`](platform-support/freebsd.md) | ✓ | 32-bit x86 FreeBSD (Pentium 4) [^x86_32-floats-return-ABI]
 `i686-unknown-linux-musl` | ✓ | 32-bit Linux with musl 1.2.3 (Pentium 4) [^x86_32-floats-return-ABI]
-[`i686-unknown-uefi`](platform-support/unknown-uefi.md) | ? | 32-bit UEFI (Pentium 4, softfloat)
+[`i686-unknown-uefi`](platform-support/unknown-uefi.md) | ? | 32-bit UEFI (Pentium 4, softfloat) [^win32-msvc-alignment]
 [`loongarch64-unknown-none`](platform-support/loongarch-none.md) | * | LoongArch64 Bare-metal (LP64D ABI)
 [`loongarch64-unknown-none-softfloat`](platform-support/loongarch-none.md) | * | LoongArch64 Bare-metal (LP64S ABI)
 [`nvptx64-nvidia-cuda`](platform-support/nvptx64-nvidia-cuda.md) | * | --emit=asm generates PTX code that [runs on NVIDIA GPUs]
@@ -317,9 +319,9 @@ target | std | host | notes
 [`i686-unknown-netbsd`](platform-support/netbsd.md) | ✓ | ✓ | NetBSD/i386 (Pentium 4) [^x86_32-floats-return-ABI]
 [`i686-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | 32-bit OpenBSD (Pentium 4) [^x86_32-floats-return-ABI]
 `i686-uwp-windows-gnu` | ✓ |  | [^x86_32-floats-return-ABI]
-[`i686-uwp-windows-msvc`](platform-support/uwp-windows-msvc.md) | ✓ |  | [^x86_32-floats-return-ABI]
+[`i686-uwp-windows-msvc`](platform-support/uwp-windows-msvc.md) | ✓ |  | [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 [`i686-win7-windows-gnu`](platform-support/win7-windows-gnu.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI]
-[`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI]
+[`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 [`i686-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | [^x86_32-floats-return-ABI]
 [`loongarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ✓ |   | LoongArch64 OpenHarmony
 [`m68k-unknown-linux-gnu`](platform-support/m68k-unknown-linux-gnu.md) | ? |  | Motorola 680x0 Linux
diff --git a/src/doc/rustc/src/platform-support/x86_64-pc-cygwin.md b/src/doc/rustc/src/platform-support/x86_64-pc-cygwin.md
index 60aaa371bbc..e98aa996a6e 100644
--- a/src/doc/rustc/src/platform-support/x86_64-pc-cygwin.md
+++ b/src/doc/rustc/src/platform-support/x86_64-pc-cygwin.md
@@ -20,8 +20,9 @@ The `target_os` of the target is `cygwin`, and it is `unix`.
 
 ## Building the target
 
-For cross-compilation you want LLVM with [llvm/llvm-project#121439 (merged)](https://github.com/llvm/llvm-project/pull/121439) applied to fix the LLVM codegen on importing external global variables from DLLs.
-No native builds on Cygwin now. It should be possible theoretically though, but might need a lot of patches.
+For cross-compilation you want LLVM at least 20.1.0-rc1.
+No native builds on Cygwin now.
+The tracking issue for host tools on Cygwin is [#137819](https://github.com/rust-lang/rust/issues/137819).
 
 ## Building Rust programs
 
diff --git a/src/doc/rustdoc/src/command-line-arguments.md b/src/doc/rustdoc/src/command-line-arguments.md
index 872592d669d..b55ddf6e0e1 100644
--- a/src/doc/rustdoc/src/command-line-arguments.md
+++ b/src/doc/rustdoc/src/command-line-arguments.md
@@ -222,6 +222,28 @@ For more, see [the chapter on documentation tests](write-documentation/documenta
 
 See also `--test`.
 
+## `--test-runtool`, `--test-runtool-arg`: program to run tests with; args to pass to it
+
+A doctest wrapper program can be specified with the `--test-runtool` flag.
+Rustdoc will execute that wrapper instead of the doctest executable when
+running tests. The first arguments to the wrapper will be any arguments
+specified with the `--test-runtool-arg` flag, followed by the path to the
+doctest executable to run.
+
+Using these options looks like this:
+
+```bash
+$ rustdoc src/lib.rs --test-runtool path/to/runner --test-runtool-arg --do-thing --test-runtool-arg --do-other-thing
+```
+
+For example, if you want to run your doctests under valgrind you might run:
+
+```bash
+$ rustdoc src/lib.rs --test-runtool valgrind
+```
+
+Another use case would be to run a test inside an emulator, or through a Virtual Machine.
+
 ## `--target`: generate documentation for the specified target triple
 
 Using this flag looks like this:
diff --git a/src/doc/rustdoc/src/read-documentation/search.md b/src/doc/rustdoc/src/read-documentation/search.md
index bace2f5f953..5635f68b1b3 100644
--- a/src/doc/rustdoc/src/read-documentation/search.md
+++ b/src/doc/rustdoc/src/read-documentation/search.md
@@ -89,7 +89,7 @@ the standard library and functions that are included in the results list:
 
 ### Non-functions in type-based search
 Certain items that are not functions are treated as though they
-were a semantically equivelent function.
+were a semantically equivalent function.
 
 For example, struct fields are treated as though they were getter methods.
 This means that a search for `CpuidResult -> u32` will show
diff --git a/src/doc/rustdoc/src/unstable-features.md b/src/doc/rustdoc/src/unstable-features.md
index d4ff69a9933..69e5a5adbec 100644
--- a/src/doc/rustdoc/src/unstable-features.md
+++ b/src/doc/rustdoc/src/unstable-features.md
@@ -631,60 +631,6 @@ The generated output (formatted) will look like this:
 `--output-format html` has no effect, as the default output is HTML. This is
 accepted on stable, even though the other options for this flag aren't.
 
-## `--enable-per-target-ignores`: allow `ignore-foo` style filters for doctests
-
- * Tracking issue: [#64245](https://github.com/rust-lang/rust/issues/64245)
-
-Using this flag looks like this:
-
-```bash
-$ rustdoc src/lib.rs -Z unstable-options --enable-per-target-ignores
-```
-
-This flag allows you to tag doctests with compiletest style `ignore-foo` filters that prevent
-rustdoc from running that test if the target triple string contains foo. For example:
-
-```rust
-///```ignore-foo,ignore-bar
-///assert!(2 == 2);
-///```
-struct Foo;
-```
-
-This will not be run when the build target is `super-awesome-foo` or `less-bar-awesome`.
-If the flag is not enabled, then rustdoc will consume the filter, but do nothing with it, and
-the above example will be run for all targets.
-If you want to preserve backwards compatibility for older versions of rustdoc, you can use
-
-```rust
-///```ignore,ignore-foo
-///assert!(2 == 2);
-///```
-struct Foo;
-```
-
-In older versions, this will be ignored on all targets, but on newer versions `ignore-gnu` will
-override `ignore`.
-
-## `--runtool`, `--runtool-arg`: program to run tests with; args to pass to it
-
- * Tracking issue: [#64245](https://github.com/rust-lang/rust/issues/64245)
-
-Using these options looks like this:
-
-```bash
-$ rustdoc src/lib.rs -Z unstable-options --runtool runner --runtool-arg --do-thing --runtool-arg --do-other-thing
-```
-
-These options can be used to run the doctest under a program, and also pass arguments to
-that program. For example, if you want to run your doctests under valgrind you might run
-
-```bash
-$ rustdoc src/lib.rs -Z unstable-options --runtool valgrind
-```
-
-Another use case would be to run a test inside an emulator, or through a Virtual Machine.
-
 ## `--with-examples`: include examples of uses of items as documentation
 
  * Tracking issue: [#88791](https://github.com/rust-lang/rust/issues/88791)
diff --git a/src/doc/rustdoc/src/write-documentation/documentation-tests.md b/src/doc/rustdoc/src/write-documentation/documentation-tests.md
index b921f677857..077b02d603d 100644
--- a/src/doc/rustdoc/src/write-documentation/documentation-tests.md
+++ b/src/doc/rustdoc/src/write-documentation/documentation-tests.md
@@ -427,6 +427,43 @@ should not be merged with the others. So the previous code should use it:
 In this case, it means that the line information will not change if you add/remove other
 doctests.
 
+### Ignoring targets
+
+Attributes starting with `ignore-` can be used to ignore doctests for specific
+targets. For example, `ignore-x86_64` will avoid building doctests when the
+target name contains `x86_64`.
+
+```rust
+/// ```ignore-x86_64
+/// assert!(2 == 2);
+/// ```
+struct Foo;
+```
+
+This doctest will not be built for targets such as `x86_64-unknown-linux-gnu`.
+
+Multiple ignore attributes can be specified to ignore multiple targets:
+
+```rust
+/// ```ignore-x86_64,ignore-windows
+/// assert!(2 == 2);
+/// ```
+struct Foo;
+```
+
+If you want to preserve backwards compatibility for older versions of rustdoc,
+you can specify both `ignore` and `ignore-`, such as:
+
+```rust
+/// ```ignore,ignore-x86_64
+/// assert!(2 == 2);
+/// ```
+struct Foo;
+```
+
+In older versions, this will be ignored on all targets, but starting with
+version CURRENT_RUSTC_VERSION, `ignore-x86_64` will override `ignore`.
+
 ### Custom CSS classes for code blocks
 
 ```rust
diff --git a/src/doc/unstable-book/src/library-features/concat-idents.md b/src/doc/unstable-book/src/library-features/concat-idents.md
index 4366172fb99..8a38d155e3d 100644
--- a/src/doc/unstable-book/src/library-features/concat-idents.md
+++ b/src/doc/unstable-book/src/library-features/concat-idents.md
@@ -2,7 +2,10 @@
 
 The tracking issue for this feature is: [#29599]
 
+This feature is deprecated, to be replaced by [`macro_metavar_expr_concat`].
+
 [#29599]: https://github.com/rust-lang/rust/issues/29599
+[`macro_metavar_expr_concat`]: https://github.com/rust-lang/rust/issues/124225
 
 ------------------------