Auto merge of #135113 - workingjubilee:rollup-yy6nxel, r=workingjubilee

Rollup of 4 pull requests

Successful merges:

 - #134925 (deny usage of special FileCheck prefixes as revision names)
 - #134996 (Add UWP (msvc) target support page)
 - #135104 (do not in-place-iterate over flatmap/flatten)
 - #135110 (library: fix adler{ -> 2}.debug)

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

5 files changed, 123 insertions, 5 deletions

diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md
index f0c3720eae1..0f45c9dbd4e 100644
--- a/src/doc/rustc/src/SUMMARY.md
+++ b/src/doc/rustc/src/SUMMARY.md
@@ -87,6 +87,7 @@
     - [*-unknown-openbsd](platform-support/openbsd.md)
     - [*-unknown-redox](platform-support/redox.md)
     - [\*-unknown-uefi](platform-support/unknown-uefi.md)
+    - [\*-uwp-windows-msvc](platform-support/uwp-windows-msvc.md)
     - [\*-wrs-vxworks](platform-support/vxworks.md)
     - [wasm32-wasip1](platform-support/wasm32-wasip1.md)
     - [wasm32-wasip1-threads](platform-support/wasm32-wasip1-threads.md)
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 24e9a3c8121..7b07d991992 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -264,7 +264,7 @@ target | std | host | notes
 [`aarch64-unknown-redox`](platform-support/redox.md) | ✓ |  | ARM64 Redox OS
 [`aarch64-unknown-teeos`](platform-support/aarch64-unknown-teeos.md) | ? |  | ARM64 TEEOS |
 [`aarch64-unknown-trusty`](platform-support/trusty.md) | ? |  |
-`aarch64-uwp-windows-msvc` | ✓ |  |
+[`aarch64-uwp-windows-msvc`](platform-support/uwp-windows-msvc.md) | ✓ |  |
 [`aarch64-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | ARM64 VxWorks OS
 `aarch64_be-unknown-linux-gnu` | ✓ | ✓ | ARM64 Linux (big-endian)
 `aarch64_be-unknown-linux-gnu_ilp32` | ✓ | ✓ | ARM64 Linux (big-endian, ILP32 ABI)
@@ -312,7 +312,7 @@ target | std | host | notes
 [`i686-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | 32-bit OpenBSD [^x86_32-floats-return-ABI]
 [`i686-unknown-redox`](platform-support/redox.md) | ✓ |  | i686 Redox OS
 `i686-uwp-windows-gnu` | ✓ |  | [^x86_32-floats-return-ABI]
-`i686-uwp-windows-msvc` | ✓ |  | [^x86_32-floats-return-ABI]
+[`i686-uwp-windows-msvc`](platform-support/uwp-windows-msvc.md) | ✓ |  | [^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-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | [^x86_32-floats-return-ABI]
 [`loongarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ✓ |   | LoongArch64 OpenHarmony
@@ -383,8 +383,8 @@ target | std | host | notes
 [`thumbv4t-none-eabi`](platform-support/armv4t-none-eabi.md) | * |  | Thumb-mode Bare Armv4T
 [`thumbv5te-none-eabi`](platform-support/armv5te-none-eabi.md) | * |  | Thumb-mode Bare Armv5TE
 [`thumbv6m-nuttx-eabi`](platform-support/nuttx.md) | * |  | ARMv6M with NuttX
-`thumbv7a-pc-windows-msvc` | ✓ |  |
-`thumbv7a-uwp-windows-msvc` | ✓ |  |
+`thumbv7a-pc-windows-msvc` |  |  |
+[`thumbv7a-uwp-windows-msvc`](platform-support/uwp-windows-msvc.md) |  |  |
 [`thumbv7em-nuttx-eabi`](platform-support/nuttx.md) | * |  | ARMv7EM with NuttX
 [`thumbv7em-nuttx-eabihf`](platform-support/nuttx.md) | * |  | ARMv7EM with NuttX, hardfloat
 [`thumbv7m-nuttx-eabi`](platform-support/nuttx.md) | * |  | ARMv7M with NuttX
@@ -406,7 +406,7 @@ target | std | host | notes
 [`x86_64-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | 64-bit OpenBSD
 [`x86_64-unknown-trusty`](platform-support/trusty.md) | ? |  |
 `x86_64-uwp-windows-gnu` | ✓ |  |
-`x86_64-uwp-windows-msvc` | ✓ |  |
+[`x86_64-uwp-windows-msvc`](platform-support/uwp-windows-msvc.md) | ✓ |  |
 [`x86_64-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 64-bit Windows 7 support
 [`x86_64-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  |
 [`x86_64h-apple-darwin`](platform-support/x86_64h-apple-darwin.md) | ✓ | ✓ | macOS with late-gen Intel (at least Haswell)
diff --git a/src/doc/rustc/src/platform-support/uwp-windows-msvc.md b/src/doc/rustc/src/platform-support/uwp-windows-msvc.md
new file mode 100644
index 00000000000..ce2ebb686fa
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/uwp-windows-msvc.md
@@ -0,0 +1,52 @@
+# `x86_64-uwp-windows-msvc`, `i686-uwp-windows-msvc`, `thumbv7a-uwp-windows-msvc` and `aarch64-uwp-windows-msvc`
+
+**Tier: 3**
+
+Windows targets for Universal Windows Platform (UWP) applications, using MSVC toolchain.
+
+## Target maintainers
+
+- [@bdbai](https://github.com/bdbai)
+
+## Requirements
+
+These targets are cross-compiled with std support. The host requirement and
+binary format are the same as the corresponding non-UWP targets (i.e.
+`x86_64-pc-windows-msvc`, `i686-pc-windows-msvc`, `thumbv7a-pc-windows-msvc`
+and `aarch64-pc-windows-msvc`).
+
+## Building the targets
+
+The targets can be built by enabling them for a `rustc` build, for example:
+
+```toml
+[build]
+build-stage = 1
+target = ["x86_64-uwp-windows-msvc", "aarch64-uwp-windows-msvc"]
+```
+
+## Building Rust programs
+
+Rust does not yet ship pre-compiled artifacts for these targets. To compile for
+these targets, you will either need to build Rust with the targets enabled (see
+"Building the targets" above), or build your own copy of `std` by using
+`build-std` or similar.
+
+Example of building a Rust project for x64 UWP using `build-std`:
+
+```pwsh
+cargo build -Z build-std=std,panic_abort --target x86_64-uwp-windows-msvc
+```
+
+## Testing
+
+Currently there is no support to run the rustc test suite for this target.
+
+## Cross-compilation toolchains and C code
+
+In general, the toolchain target should match the corresponding non-UWP
+targets. Beware that not all Win32 APIs behave the same way in UWP, and some
+are restricted in [AppContainer](https://learn.microsoft.com/en-us/windows/win32/secauthz/appcontainer-for-legacy-applications-)
+or even not available at all. If the C code being compiled happens to use any
+of restricted or unavailable APIs, consider using allowed alternatives or
+disable certain feature sets to avoid using them.
diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index 48149e3b897..8c96554738e 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -934,6 +934,9 @@ fn iter_header(
 
 impl Config {
     fn parse_and_update_revisions(&self, testfile: &Path, line: &str, existing: &mut Vec<String>) {
+        const FORBIDDEN_REVISION_NAMES: [&str; 9] =
+            ["CHECK", "COM", "NEXT", "SAME", "EMPTY", "NOT", "COUNT", "DAG", "LABEL"];
+
         if let Some(raw) = self.parse_name_value_directive(line, "revisions") {
             if self.mode == Mode::RunMake {
                 panic!("`run-make` tests do not support revisions: {}", testfile.display());
@@ -948,6 +951,15 @@ impl Config {
                         raw,
                         testfile.display()
                     );
+                } else if matches!(self.mode, Mode::Assembly | Mode::Codegen | Mode::MirOpt)
+                    && FORBIDDEN_REVISION_NAMES.contains(&revision.as_str())
+                {
+                    panic!(
+                        "revision name `{revision}` is not permitted in a test suite that uses `FileCheck` annotations\n\
+                         as it is confusing when used as custom `FileCheck` prefix: `{revision}` in line `{}`: {}",
+                        raw,
+                        testfile.display()
+                    );
                 }
                 existing.push(revision);
             }
diff --git a/src/tools/compiletest/src/header/tests.rs b/src/tools/compiletest/src/header/tests.rs
index 618b66dfd4c..25bb1a5f428 100644
--- a/src/tools/compiletest/src/header/tests.rs
+++ b/src/tools/compiletest/src/header/tests.rs
@@ -554,6 +554,59 @@ fn test_duplicate_revisions() {
 }
 
 #[test]
+#[should_panic(
+    expected = "revision name `CHECK` is not permitted in a test suite that uses `FileCheck` annotations"
+)]
+fn test_assembly_mode_forbidden_revisions() {
+    let config = cfg().mode("assembly").build();
+    parse_rs(&config, "//@ revisions: CHECK");
+}
+
+#[test]
+#[should_panic(
+    expected = "revision name `CHECK` is not permitted in a test suite that uses `FileCheck` annotations"
+)]
+fn test_codegen_mode_forbidden_revisions() {
+    let config = cfg().mode("codegen").build();
+    parse_rs(&config, "//@ revisions: CHECK");
+}
+
+#[test]
+#[should_panic(
+    expected = "revision name `CHECK` is not permitted in a test suite that uses `FileCheck` annotations"
+)]
+fn test_miropt_mode_forbidden_revisions() {
+    let config = cfg().mode("mir-opt").build();
+    parse_rs(&config, "//@ revisions: CHECK");
+}
+
+#[test]
+fn test_forbidden_revisions_allowed_in_non_filecheck_dir() {
+    let revisions = ["CHECK", "COM", "NEXT", "SAME", "EMPTY", "NOT", "COUNT", "DAG", "LABEL"];
+    let modes = [
+        "pretty",
+        "debuginfo",
+        "rustdoc",
+        "rustdoc-json",
+        "codegen-units",
+        "incremental",
+        "ui",
+        "js-doc-test",
+        "coverage-map",
+        "coverage-run",
+        "crashes",
+    ];
+
+    for rev in revisions {
+        let content = format!("//@ revisions: {rev}");
+        for mode in modes {
+            let config = cfg().mode(mode).build();
+            parse_rs(&config, &content);
+        }
+    }
+}
+
+#[test]
 fn ignore_arch() {
     let archs = [
         ("x86_64-unknown-linux-gnu", "x86_64"),