Auto merge of #128134 - joboet:move_pal_alloc, r=cupiver

std: move allocators to `sys`

Part of #117276.

1 files changed, 30 insertions, 0 deletions

diff --git a/library/std/src/sys/alloc/solid.rs b/library/std/src/sys/alloc/solid.rs
new file mode 100644
index 00000000000..abb534a1c5c
--- /dev/null
+++ b/library/std/src/sys/alloc/solid.rs
@@ -0,0 +1,30 @@
+use super::{realloc_fallback, MIN_ALIGN};
+use crate::alloc::{GlobalAlloc, Layout, System};
+
+#[stable(feature = "alloc_system_type", since = "1.28.0")]
+unsafe impl GlobalAlloc for System {
+    #[inline]
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
+            unsafe { libc::malloc(layout.size()) as *mut u8 }
+        } else {
+            unsafe { libc::memalign(layout.align(), layout.size()) as *mut u8 }
+        }
+    }
+
+    #[inline]
+    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
+        unsafe { libc::free(ptr as *mut libc::c_void) }
+    }
+
+    #[inline]
+    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+        unsafe {
+            if layout.align() <= MIN_ALIGN && layout.align() <= new_size {
+                libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8
+            } else {
+                realloc_fallback(self, ptr, layout, new_size)
+            }
+        }
+    }
+}