redesign of the interface to the unikernel HermitCore

- the old interface between HermitCore and the Rust Standard Library
  based on a small C library (newlib)
- remove this interface and call directly the unikernel
- remove the dependency to the HermitCore linker
- use rust-lld as linker

1 files changed, 40 insertions, 0 deletions

diff --git a/src/libstd/sys/hermit/alloc.rs b/src/libstd/sys/hermit/alloc.rs
new file mode 100644
index 00000000000..802a179fb67
--- /dev/null
+++ b/src/libstd/sys/hermit/alloc.rs
@@ -0,0 +1,40 @@
+use crate::alloc::{GlobalAlloc, Layout, System};
+use crate::ptr;
+
+extern "C" {
+    fn sys_malloc(size: usize, align: usize) -> *mut u8;
+    fn sys_realloc(ptr: *mut u8, size: usize, align: usize, new_size: usize) -> *mut u8;
+    fn sys_free(ptr: *mut u8, size: usize, align: usize);
+}
+
+#[stable(feature = "alloc_system_type", since = "1.28.0")]
+unsafe impl GlobalAlloc for System {
+    #[inline]
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        sys_malloc(layout.size(), layout.align())
+    }
+
+    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+        let addr = sys_malloc(layout.size(), layout.align());
+
+        if !addr.is_null() {
+            ptr::write_bytes(
+                addr,
+                0x00,
+                layout.size()
+            );
+        }
+
+        addr
+    }
+
+    #[inline]
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        sys_free(ptr, layout.size(), layout.align())
+    }
+
+    #[inline]
+    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+        sys_realloc(ptr, layout.size(), layout.align(), new_size)
+    }
+}