From 456baa0cc9a0212e821724a1004111f215940b34 Mon Sep 17 00:00:00 2001
From: Paul Daniel Faria <Nashenas88@users.noreply.github.com>
Date: Wed, 20 Jan 2021 16:29:26 -0500
Subject: [PATCH 1/2] Fix file descriptor ranges for fuchsia

Fuchsia does not restrict the range of valid values for a file descriptor, so
the previous change that marked -1 as an invalid file descriptor does not
apply to fuchsia.
---
 library/std/src/sys/unix/fd.rs       |  9 ++++++---
 library/std/src/sys/unix/fd/tests.rs | 11 ++++++++++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/library/std/src/sys/unix/fd.rs b/library/std/src/sys/unix/fd.rs
index 821851a6c65b7..dca48d35818ed 100644
--- a/library/std/src/sys/unix/fd.rs
+++ b/library/std/src/sys/unix/fd.rs
@@ -12,11 +12,11 @@ use crate::sys_common::AsInner;
 use libc::{c_int, c_void};
 
 #[derive(Debug)]
-#[rustc_layout_scalar_valid_range_start(0)]
+#[cfg_attr(not(target_os = "fuchsia"), rustc_layout_scalar_valid_range_start(0))]
 // libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
 // 32-bit c_int. Below is -2, in two's complement, but that only works out
 // because c_int is 32 bits.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
+#[cfg_attr(not(target_os = "fuchsia"), rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE))]
 pub struct FileDesc {
     fd: c_int,
 }
@@ -68,7 +68,10 @@ const fn max_iov() -> usize {
 
 impl FileDesc {
     pub fn new(fd: c_int) -> FileDesc {
-        assert_ne!(fd, -1i32);
+        if cfg!(not(target_os = "fuchsia")) {
+            assert_ne!(fd, -1i32);
+        }
+
         // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
         unsafe { FileDesc { fd } }
     }
diff --git a/library/std/src/sys/unix/fd/tests.rs b/library/std/src/sys/unix/fd/tests.rs
index c9520485c3c7c..c1d5f38dda262 100644
--- a/library/std/src/sys/unix/fd/tests.rs
+++ b/library/std/src/sys/unix/fd/tests.rs
@@ -3,7 +3,16 @@ use core::mem::ManuallyDrop;
 
 #[test]
 fn limit_vector_count() {
-    let stdout = ManuallyDrop::new(unsafe { FileDesc { fd: 1 } });
+    let stdout = ManuallyDrop::new(
+        #[cfg(not(target_os = "fuchsia"))]
+        {
+            unsafe { FileDesc { fd: 1 } }
+        },
+        #[cfg(target_os = "fuchsia")]
+        {
+            FileDesc { fd: 1 }
+        },
+    );
     let bufs = (0..1500).map(|_| IoSlice::new(&[])).collect::<Vec<_>>();
     assert!(stdout.write_vectored(&bufs).is_ok());
 }

From a32610d2f39146191f393cb7d4925de78a37071a Mon Sep 17 00:00:00 2001
From: Paul Daniel Faria <Nashenas88@users.noreply.github.com>
Date: Thu, 21 Jan 2021 09:48:36 -0500
Subject: [PATCH 2/2] Use cfg_attr to avoid repetition in fd test

---
 library/std/src/sys/unix/fd/tests.rs | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/library/std/src/sys/unix/fd/tests.rs b/library/std/src/sys/unix/fd/tests.rs
index c1d5f38dda262..e095ccc2ac083 100644
--- a/library/std/src/sys/unix/fd/tests.rs
+++ b/library/std/src/sys/unix/fd/tests.rs
@@ -4,12 +4,8 @@ use core::mem::ManuallyDrop;
 #[test]
 fn limit_vector_count() {
     let stdout = ManuallyDrop::new(
-        #[cfg(not(target_os = "fuchsia"))]
-        {
-            unsafe { FileDesc { fd: 1 } }
-        },
-        #[cfg(target_os = "fuchsia")]
-        {
+        #[cfg_attr(target_os = "fuchsia", allow(unused_unsafe))]
+        unsafe {
             FileDesc { fd: 1 }
         },
     );