Auto merge of #43348 - kennytm:fix-24658-doc-every-platform, r=alexcrichton

Expose all OS-specific modules in libstd doc.

1. Uses the special `--cfg dox` configuration passed by rustbuild when running `rustdoc`. Changes the `#[cfg(platform)]` into `#[cfg(any(dox, platform))]` so that platform-specific API are visible to rustdoc.

2. Since platform-specific implementations often won't compile correctly on other platforms, `rustdoc` is changed to apply `everybody_loops` to the functions during documentation and doc-test harness.

3. Since platform-specific code are documented on all platforms now, it could confuse users who found a useful API but is non-portable. Also, their examples will be doc-tested, so must be excluded when not testing on the native platform. An undocumented attribute `#[doc(cfg(...))]` is introduced to serve the above purposed.

Fixes #24658 (Does _not_ fully implement #1998).

2 files changed, 11 insertions, 2 deletions

diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index 4785cefd6b4..ba54ca6ea18 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -301,7 +301,7 @@ pub const PIPE_READMODE_BYTE: DWORD = 0x00000000;
 pub const FD_SETSIZE: usize = 64;
 
 #[repr(C)]
-#[cfg(target_arch = "x86")]
+#[cfg(not(target_pointer_width = "64"))]
 pub struct WSADATA {
     pub wVersion: WORD,
     pub wHighVersion: WORD,
@@ -312,7 +312,7 @@ pub struct WSADATA {
     pub lpVendorInfo: *mut u8,
 }
 #[repr(C)]
-#[cfg(target_arch = "x86_64")]
+#[cfg(target_pointer_width = "64")]
 pub struct WSADATA {
     pub wVersion: WORD,
     pub wHighVersion: WORD,
@@ -768,6 +768,14 @@ pub struct FLOATING_SAVE_AREA {
     _Dummy: [u8; 512] // FIXME: Fill this out
 }
 
+// FIXME(#43348): This structure is used for backtrace only, and a fake
+// definition is provided here only to allow rustdoc to pass type-check. This
+// will not appear in the final documentation. This should be also defined for
+// other architectures supported by Windows such as ARM, and for historical
+// interest, maybe MIPS and PowerPC as well.
+#[cfg(all(dox, not(any(target_arch = "x86_64", target_arch = "x86"))))]
+pub enum CONTEXT {}
+
 #[repr(C)]
 pub struct SOCKADDR_STORAGE_LH {
     pub ss_family: ADDRESS_FAMILY,
diff --git a/src/libstd/sys/windows/ext/mod.rs b/src/libstd/sys/windows/ext/mod.rs
index 11b1337a8ae..4b458d293bc 100644
--- a/src/libstd/sys/windows/ext/mod.rs
+++ b/src/libstd/sys/windows/ext/mod.rs
@@ -17,6 +17,7 @@
 //! platform-agnostic idioms would not normally support.
 
 #![stable(feature = "rust1", since = "1.0.0")]
+#![doc(cfg(windows))]
 
 pub mod ffi;
 pub mod fs;