1 files changed, 76 insertions, 18 deletions

diff --git a/src/libao.ads b/src/libao.ads
index db5f7ce..c2013c5 100644
--- a/src/libao.ads
+++ b/src/libao.ads
@@ -16,7 +16,7 @@ private with
     Ada.Finalization,
     Ada.Containers.Vectors,
     Interfaces.C.Strings,
-    System;
+    System.Storage_Elements;
 
 
 package Libao is
@@ -58,7 +58,7 @@ package Libao is
 
     function Priority_Level
            (Attributes : in Info)
-        return Positive;
+        return Natural;
 
     function Comment
            (Attributes : in Info)
@@ -78,19 +78,54 @@ package Libao is
 
     Empty_Options : constant Option_List;
 
+    function Length
+           (Options : in Option_List)
+        return Natural;
+
+    function Key
+           (Options : in Option_List;
+            Index   : in Positive)
+        return String;
+
+    function Value
+           (Options : in Option_List;
+            Index   : in Positive)
+        return String;
+
 
     type Sample_Format is tagged private;
     type Channel_Mnemonic is (L, R, C, M, CL, CR, BL, BR, BC, SL, SR, LFE, A1, A2, A3, A4, X);
     type Mnemonic_Array is array (Positive range <>) of Channel_Mnemonic;
 
+    Stereo       : constant Mnemonic_Array := (L, R);
+    Quadraphonic : constant Mnemonic_Array := (L, R, BL, BR);
+
     function Create
            (Bits, Rate, Channels : in Positive;
             Byte_Format          : in Endianness;
             Channel_Matrix       : in Mnemonic_Array)
-        return Sample_Format;
+        return Sample_Format
+    with Pre => Channel_Matrix'Length = Channels;
 
-    Stereo       : constant Mnemonic_Array := (L, R);
-    Quadraphonic : constant Mnemonic_Array := (L, R, BL, BR);
+    function Bits
+           (Format : in Sample_Format)
+        return Positive;
+
+    function Rate
+           (Format : in Sample_Format)
+        return Positive;
+
+    function Channels
+           (Format : in Sample_Format)
+        return Positive;
+
+    function Byte_Format
+           (Format : in Sample_Format)
+        return Endianness;
+
+    function Channel_Matrix
+           (Format : in Sample_Format)
+        return Mnemonic_Array;
 
 
 
@@ -211,33 +246,61 @@ package Libao is
 private
 
 
+    package Storage renames System.Storage_Elements;
+    use type Interfaces.C.size_t, Storage.Integer_Address;
+
+
+    Null_Pointer : constant Storage.Integer_Address := Storage.To_Integer (System.Null_Address);
+
+
     pragma Linker_Options ("-lao");
 
 
+    function c_pointer_size
+        return Interfaces.C.size_t;
+    pragma Import (C, c_pointer_size, "c_pointer_size");
+
+    --  If this fails then we are on an architecture that for whatever reason
+    --  has significant problems interfacing between C and Ada
+    pragma Assert
+       (c_pointer_size * Interfaces.C.CHAR_BIT = Storage.Integer_Address'Size,
+        "Size of C void pointers and size of Ada address values do not match");
+
+
     for Data_Buffer'Component_Size use Interfaces.C.CHAR_BIT;
 
 
+    package Address_Vectors is new Ada.Containers.Vectors
+       (Index_Type   => Positive,
+        Element_Type => Storage.Integer_Address,
+        "="          => Storage."=");
+
+
     procedure Do_Append
-           (Ptr   : in out System.Address;
-            Key   : in     Interfaces.C.char_array;
-            Value : in     Interfaces.C.char_array);
+           (Ptr_List : in out Address_Vectors.Vector;
+            Key      : in     Interfaces.C.char_array;
+            Value    : in     Interfaces.C.char_array);
 
     procedure Do_Close
-           (Ptr : in System.Address);
+           (Ptr : in Storage.Integer_Address);
+
+    function Head_Pointer
+           (This : in Address_Vectors.Vector)
+        return Storage.Integer_Address;
 
 
     type Device is tagged record
-        Ptr : System.Address := System.Null_Address;
+        Ptr : Storage.Integer_Address := Null_Pointer;
     end record;
 
 
     type Info is tagged record
-        Ptr : System.Address := System.Null_Address;
+        Ptr : Storage.Integer_Address := Null_Pointer;
     end record;
 
 
     type Option_List is new Ada.Finalization.Controlled with record
-        Ptr : System.Address := System.Null_Address;
+        Ptr_List : Address_Vectors.Vector := Address_Vectors.Empty_Vector;
     end record;
 
     overriding procedure Adjust
@@ -247,7 +310,7 @@ private
            (This : in out Option_List);
 
     Empty_Options : constant Option_List :=
-        (Ada.Finalization.Controlled with Ptr => System.Null_Address);
+        (Ada.Finalization.Controlled with Ptr_List => Address_Vectors.Empty_Vector);
 
 
     type C_Sample_Format is record
@@ -270,11 +333,6 @@ private
 
 
     --  Keep track of open devices
-    package Address_Vectors is new Ada.Containers.Vectors
-       (Index_Type   => Positive,
-        Element_Type => System.Address,
-        "="          => System."=");
-
     Device_List : Address_Vectors.Vector := Address_Vectors.Empty_Vector;