added an incomplete and experimental file package

lib/posix/h2-sysapi-file.adb

@@ -0,0 +1,81 @@
+with Interfaces.C;
+with H2.Pool;
+
+separate (H2.Sysapi)
+
+package body File is
+
+	package C renames Interfaces.C;
+	use type C.int;
+
+	--function sys_open (path: ; flags: C.int; mode: C.int) return C.int;
+	function sys_open (path: Slim_String; flags: C.int; mode: C.int) return C.int;
+	pragma Import (C, sys_open, "open");
+
+	procedure sys_close (fd: C.int);
+	pragma Import (C, sys_close, "close");
+
+	type Posix_File_Record is new File_Record with record
+		Pool: Storage_Pool_Pointer := null;
+		Handle: C.int := Interfaces.C."-"(1);
+	end record;
+	type Posix_File_Pointer is access all Posix_File_Record;
+
+	function Flag_To_System (Flag: in Flag_Record) return C.int is
+	begin
+		return 0;
+	end Flag_To_System;
+
+	function Mode_To_System (Mode: in Mode_Record) return C.int is
+	begin
+		return 0;
+	end Mode_To_System;
+
+	procedure Open (File: out File_Pointer;
+	                Name: in  Slim_String;
+	                Flag: in  Flag_Record;
+	                Mode: in  Mode_Record;
+	                Pool: in  Storage_Pool_Pointer := null) is
+
+		package P is new H2.Pool (Posix_File_Record, Posix_File_Pointer, Pool);
+		F: Posix_File_Pointer;
+		
+	begin
+		F := P.Allocate;
+		F.Pool := Pool;
+
+		--F.Handle := sys_open (Interfaces.C.char_array(Name & Slim.Character'Val(0)), 0, 0);
+		F.Handle := sys_open (Name, Flag_To_System(Flag), Mode_To_System(Mode));
+		if F.Handle <= -1 then
+			raise Constraint_Error; -- TODO: raise a proper exception.
+		end if;
+
+		File := File_Pointer(F);
+	end Open;
+
+	procedure Open (File: out File_Pointer;
+	                Name: in  Wide_String;
+	                Flag: in  Flag_Record;
+	                Mode: in  Mode_Record;
+	                Pool: in  Storage_Pool_Pointer := null) is	
+	begin
+		Open (File, Wide_To_Slim(Name), Flag, Mode, Pool);
+	end Open;
+
+	procedure Close (File: in out File_Pointer) is
+		F: Posix_File_Pointer;
+	begin
+		F := Posix_File_Pointer(File);
+		sys_close (F.Handle);
+		F.Handle := Interfaces.C."-"(1);
+
+		declare
+			package P is new H2.Pool (Posix_File_Record, Posix_File_Pointer, F.Pool);
+		begin
+			P.Deallocate (F);
+		end;
+
+		File := null;
+	end Close;
+
+end File;