Move os stuff to OS specific files

core/crypto/hash/hash.odin

@@ -1,16 +1,15 @@
 package crypto_hash
 
 /*
-    Copyright 2021 zhibog
-    Made available under the BSD-3 license.
+	Copyright 2021 zhibog
+	Made available under the BSD-3 license.
 
-    List of contributors:
-        zhibog, dotbmp:  Initial implementation.
+	List of contributors:
+		zhibog, dotbmp:  Initial implementation.
 */
 
 import "core:io"
 import "core:mem"
-import "core:os"
 
 // hash_bytes will hash the given input and return the computed digest
 // in a newly allocated slice.
@@ -87,36 +86,3 @@ hash_stream :: proc(
 
 	return dst, io.Error.None
 }
-
-// hash_file will read the file provided by the given handle and return the
-// computed digest in a newly allocated slice.
-hash_file :: proc(
-	algorithm: Algorithm,
-	hd: os.Handle,
-	load_at_once := false,
-	allocator := context.allocator,
-) -> (
-	[]byte,
-	io.Error,
-) {
-	if !load_at_once {
-		return hash_stream(algorithm, os.stream_from_handle(hd), allocator)
-	}
-
-	buf, ok := os.read_entire_file(hd, allocator)
-	if !ok {
-		return nil, io.Error.Unknown
-	}
-	defer delete(buf, allocator)
-
-	return hash_bytes(algorithm, buf, allocator), io.Error.None
-}
-
-hash :: proc {
-	hash_stream,
-	hash_file,
-	hash_bytes,
-	hash_string,
-	hash_bytes_to_buffer,
-	hash_string_to_buffer,
-}

core/crypto/hash/hash_freestanding.odin

@@ -0,0 +1,10 @@
+//+build freestanding
+package crypto_hash
+
+hash :: proc {
+	hash_stream,
+	hash_bytes,
+	hash_string,
+	hash_bytes_to_buffer,
+	hash_string_to_buffer,
+}

core/crypto/hash/hash_os.odin

@@ -0,0 +1,37 @@
+//+build !freestanding
+package crypto_hash
+
+import "core:os"
+
+// hash_file will read the file provided by the given handle and return the
+// computed digest in a newly allocated slice.
+hash_file :: proc(
+	algorithm: Algorithm,
+	hd: os.Handle,
+	load_at_once := false,
+	allocator := context.allocator,
+) -> (
+	[]byte,
+	io.Error,
+) {
+	if !load_at_once {
+		return hash_stream(algorithm, os.stream_from_handle(hd), allocator)
+	}
+
+	buf, ok := os.read_entire_file(hd, allocator)
+	if !ok {
+		return nil, io.Error.Unknown
+	}
+	defer delete(buf, allocator)
+
+	return hash_bytes(algorithm, buf, allocator), io.Error.None
+}
+
+hash :: proc {
+	hash_stream,
+	hash_file,
+	hash_bytes,
+	hash_string,
+	hash_bytes_to_buffer,
+	hash_string_to_buffer,
+}