feat: add cygwin support (#2610)

* feat: add cygwin support

* Remove no_mangle

* Add check-cfg for cygwin target

* feat: full cygwin support

* feat: update libc to add cygwin support

* feat: add statfs support for cygwin

* fix: some tests for cygwin

* fix: ignore failed tests on cygwin

* Format code

* fix: mark from_i32 pub(crate)

* test: restore symlink tests on cygwin

* test: test user passwd on cygwin

* test: restore more tests on cygwin

They pass on Cygwin, but not on MSYS2 as intended.

Author: Berrysoft

Cargo.toml

@@ -28,7 +28,7 @@ targets = [
 ]
 
 [dependencies]
-libc = { version = "0.2.166", features = ["extra_traits"] }
+libc = { version = "0.2.171", features = ["extra_traits"] }
 bitflags = "2.3.3"
 cfg-if = "1.0"
 pin-utils = { version = "0.1.0", optional = true }

build.rs

@@ -30,4 +30,6 @@ fn main() {
     // Below are custom cfg values set during some CI steps.
     println!("cargo:rustc-check-cfg=cfg(fbsd14)");
     println!("cargo:rustc-check-cfg=cfg(qemu)");
+    // Cygwin target, added in 1.86
+    println!("cargo:rustc-check-cfg=cfg(target_os, values(\"cygwin\"))");
 }

src/dir.rs

@@ -287,6 +287,7 @@ impl Entry {
                          target_os = "fuchsia",
                          target_os = "haiku",
                          target_os = "hurd",
+                         target_os = "cygwin",
                          solarish,
                          linux_android,
                          apple_targets))] {