Rollup merge of rust-lang#88619 - GuillaumeGomez:simplify-std-os-reexports, r=Amanieu

Remove `cfg(doc)` from std::os module reexports to fix rustdoc linking issues

Fixes rust-lang#88304.

I tested it based on rust-lang#88292.

Not sure if it's the best approach, but at least it makes thing a bit simpler.

cc ``@jyn514``

Author: GuillaumeGomez

library/std/src/os/mod.rs

@@ -10,117 +10,121 @@ pub mod raw;
 // of a macro that is not vendored by Rust and included in the toolchain.
 // See https://github.com/rust-analyzer/rust-analyzer/issues/6038.
 
+// On certain platforms right now the "main modules" modules that are
+// documented don't compile (missing things in `libc` which is empty),
+// so just omit them with an empty module and add the "unstable" attribute.
+
+// Unix, linux, wasi and windows are handled a bit differently.
 #[cfg(all(
     doc,
-    not(any(
+    any(
         all(target_arch = "wasm32", not(target_os = "wasi")),
         all(target_vendor = "fortanix", target_env = "sgx")
-    ))
+    )
 ))]
-#[path = "."]
-mod doc {
-    // When documenting std we want to show the `unix`, `windows`, `linux` and `wasi`
-    // modules as these are the "main modules" that are used across platforms,
-    // so these modules are enabled when `cfg(doc)` is set.
-    // This should help show platform-specific functionality in a hopefully cross-platform
-    // way in the documentation.
-
-    pub mod unix;
-
-    pub mod linux;
-
-    pub mod wasi;
-
-    pub mod windows;
-}
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod unix {}
 #[cfg(all(
     doc,
     any(
         all(target_arch = "wasm32", not(target_os = "wasi")),
         all(target_vendor = "fortanix", target_env = "sgx")
     )
 ))]
-mod doc {
-    // On certain platforms right now the "main modules" modules that are
-    // documented don't compile (missing things in `libc` which is empty),
-    // so just omit them with an empty module.
-
-    #[unstable(issue = "none", feature = "std_internals")]
-    pub mod unix {}
-
-    #[unstable(issue = "none", feature = "std_internals")]
-    pub mod linux {}
-
-    #[unstable(issue = "none", feature = "std_internals")]
-    pub mod wasi {}
-
-    #[unstable(issue = "none", feature = "std_internals")]
-    pub mod windows {}
-}
-#[cfg(doc)]
-#[stable(feature = "os", since = "1.0.0")]
-pub use doc::*;
-
-#[cfg(not(doc))]
-#[path = "."]
-mod imp {
-    // If we're not documenting std then we only expose modules appropriate for the
-    // current platform.
-
-    #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))]
-    pub mod fortanix_sgx;
-
-    #[cfg(target_os = "hermit")]
-    #[path = "hermit/mod.rs"]
-    pub mod unix;
-
-    #[cfg(target_os = "android")]
-    pub mod android;
-    #[cfg(target_os = "dragonfly")]
-    pub mod dragonfly;
-    #[cfg(target_os = "emscripten")]
-    pub mod emscripten;
-    #[cfg(target_os = "espidf")]
-    pub mod espidf;
-    #[cfg(target_os = "freebsd")]
-    pub mod freebsd;
-    #[cfg(target_os = "fuchsia")]
-    pub mod fuchsia;
-    #[cfg(target_os = "haiku")]
-    pub mod haiku;
-    #[cfg(target_os = "illumos")]
-    pub mod illumos;
-    #[cfg(target_os = "ios")]
-    pub mod ios;
-    #[cfg(target_os = "l4re")]
-    pub mod linux;
-    #[cfg(target_os = "linux")]
-    pub mod linux;
-    #[cfg(target_os = "macos")]
-    pub mod macos;
-    #[cfg(target_os = "netbsd")]
-    pub mod netbsd;
-    #[cfg(target_os = "openbsd")]
-    pub mod openbsd;
-    #[cfg(target_os = "redox")]
-    pub mod redox;
-    #[cfg(target_os = "solaris")]
-    pub mod solaris;
-    #[cfg(unix)]
-    pub mod unix;
-
-    #[cfg(target_os = "vxworks")]
-    pub mod vxworks;
-
-    #[cfg(target_os = "wasi")]
-    pub mod wasi;
-
-    #[cfg(windows)]
-    pub mod windows;
-}
-#[cfg(not(doc))]
-#[stable(feature = "os", since = "1.0.0")]
-pub use imp::*;
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod linux {}
+#[cfg(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+))]
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod wasi {}
+#[cfg(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+))]
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod windows {}
+
+// unix
+#[cfg(not(any(
+    all(target_arch = "wasm32", not(target_os = "wasi")),
+    all(target_vendor = "fortanix", target_env = "sgx")
+)))]
+#[cfg(all(not(doc), target_os = "hermit"))]
+#[path = "hermit/mod.rs"]
+pub mod unix;
+#[cfg(not(any(
+    all(target_arch = "wasm32", not(target_os = "wasi")),
+    all(target_vendor = "fortanix", target_env = "sgx")
+)))]
+#[cfg(any(unix, doc))]
+pub mod unix;
+
+// linux
+#[cfg(not(any(
+    all(target_arch = "wasm32", not(target_os = "wasi")),
+    all(target_vendor = "fortanix", target_env = "sgx")
+)))]
+#[cfg(any(target_os = "linux", target_os = "l4re", doc))]
+pub mod linux;
+
+// wasi
+#[cfg(not(any(
+    all(target_arch = "wasm32", not(target_os = "wasi")),
+    all(target_vendor = "fortanix", target_env = "sgx")
+)))]
+#[cfg(any(target_os = "wasi", doc))]
+pub mod wasi;
+
+// windows
+#[cfg(not(any(
+    all(target_arch = "wasm32", not(target_os = "wasi")),
+    all(target_vendor = "fortanix", target_env = "sgx")
+)))]
+#[cfg(any(windows, doc))]
+pub mod windows;
+
+// Others.
+#[cfg(target_os = "android")]
+pub mod android;
+#[cfg(target_os = "dragonfly")]
+pub mod dragonfly;
+#[cfg(target_os = "emscripten")]
+pub mod emscripten;
+#[cfg(target_os = "espidf")]
+pub mod espidf;
+#[cfg(all(target_vendor = "fortanix", target_env = "sgx"))]
+pub mod fortanix_sgx;
+#[cfg(target_os = "freebsd")]
+pub mod freebsd;
+#[cfg(target_os = "fuchsia")]
+pub mod fuchsia;
+#[cfg(target_os = "haiku")]
+pub mod haiku;
+#[cfg(target_os = "illumos")]
+pub mod illumos;
+#[cfg(target_os = "ios")]
+pub mod ios;
+#[cfg(target_os = "macos")]
+pub mod macos;
+#[cfg(target_os = "netbsd")]
+pub mod netbsd;
+#[cfg(target_os = "openbsd")]
+pub mod openbsd;
+#[cfg(target_os = "redox")]
+pub mod redox;
+#[cfg(target_os = "solaris")]
+pub mod solaris;
+
+#[cfg(target_os = "vxworks")]
+pub mod vxworks;
 
 #[cfg(any(unix, target_os = "wasi", doc))]
 mod fd;