Consolidate wasi alloc with unix alloc.

Author: ehuss

library/std/src/sys/unix/alloc.rs

@@ -52,46 +52,48 @@ unsafe impl GlobalAlloc for System {
     }
 }
 
-#[cfg(any(
-    target_os = "android",
-    target_os = "illumos",
-    target_os = "redox",
-    target_os = "solaris"
-))]
-#[inline]
-unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
-    // On android we currently target API level 9 which unfortunately
-    // doesn't have the `posix_memalign` API used below. Instead we use
-    // `memalign`, but this unfortunately has the property on some systems
-    // where the memory returned cannot be deallocated by `free`!
-    //
-    // Upon closer inspection, however, this appears to work just fine with
-    // Android, so for this platform we should be fine to call `memalign`
-    // (which is present in API level 9). Some helpful references could
-    // possibly be chromium using memalign [1], attempts at documenting that
-    // memalign + free is ok [2] [3], or the current source of chromium
-    // which still uses memalign on android [4].
-    //
-    // [1]: https://codereview.chromium.org/10796020/
-    // [2]: https://code.google.com/p/android/issues/detail?id=35391
-    // [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579
-    // [4]: https://chromium.googlesource.com/chromium/src/base/+/master/
-    //                                       /memory/aligned_memory.cc
-    libc::memalign(layout.align(), layout.size()) as *mut u8
-}
-
-#[cfg(not(any(
-    target_os = "android",
-    target_os = "illumos",
-    target_os = "redox",
-    target_os = "solaris"
-)))]
-#[inline]
-unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
-    let mut out = ptr::null_mut();
-    // posix_memalign requires that the alignment be a multiple of `sizeof(void*)`.
-    // Since these are all powers of 2, we can just use max.
-    let align = layout.align().max(crate::mem::size_of::<usize>());
-    let ret = libc::posix_memalign(&mut out, align, layout.size());
-    if ret != 0 { ptr::null_mut() } else { out as *mut u8 }
+cfg_if::cfg_if! {
+    if #[cfg(any(
+        target_os = "android",
+        target_os = "illumos",
+        target_os = "redox",
+        target_os = "solaris"
+    ))] {
+        #[inline]
+        unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
+            // On android we currently target API level 9 which unfortunately
+            // doesn't have the `posix_memalign` API used below. Instead we use
+            // `memalign`, but this unfortunately has the property on some systems
+            // where the memory returned cannot be deallocated by `free`!
+            //
+            // Upon closer inspection, however, this appears to work just fine with
+            // Android, so for this platform we should be fine to call `memalign`
+            // (which is present in API level 9). Some helpful references could
+            // possibly be chromium using memalign [1], attempts at documenting that
+            // memalign + free is ok [2] [3], or the current source of chromium
+            // which still uses memalign on android [4].
+            //
+            // [1]: https://codereview.chromium.org/10796020/
+            // [2]: https://code.google.com/p/android/issues/detail?id=35391
+            // [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579
+            // [4]: https://chromium.googlesource.com/chromium/src/base/+/master/
+            //                                       /memory/aligned_memory.cc
+            libc::memalign(layout.align(), layout.size()) as *mut u8
+        }
+    } else if #[cfg(target_os = "wasi")] {
+        #[inline]
+        unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
+            libc::aligned_alloc(layout.align(), layout.size()) as *mut u8
+        }
+    } else {
+        #[inline]
+        unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
+            let mut out = ptr::null_mut();
+            // posix_memalign requires that the alignment be a multiple of `sizeof(void*)`.
+            // Since these are all powers of 2, we can just use max.
+            let align = layout.align().max(crate::mem::size_of::<usize>());
+            let ret = libc::posix_memalign(&mut out, align, layout.size());
+            if ret != 0 { ptr::null_mut() } else { out as *mut u8 }
+        }
+    }
 }

library/std/src/sys/wasi/alloc.rs

@@ -17,6 +17,7 @@
 use crate::io as std_io;
 use crate::mem;
 
+#[path = "../unix/alloc.rs"]
 pub mod alloc;
 pub mod args;
 #[path = "../unsupported/cmath.rs"]