spec: add initial vtable stubs

CMakeLists.txt

@@ -32,6 +32,7 @@ add_custom_command (
 OUTPUT
     "${CMAKE_CURRENT_BINARY_DIR}/vk.hpp"
     "${CMAKE_CURRENT_BINARY_DIR}/icd/dispatch.cpp"
+    "${CMAKE_CURRENT_BINARY_DIR}/icd/vtable.hpp"
 COMMENT
     "[spec.py] vk.hpp"
 COMMAND
@@ -39,6 +40,7 @@ COMMAND
     "${CMAKE_CURRENT_SOURCE_DIR}/tools/spec.py"
     "--src" "${CMAKE_CURRENT_SOURCE_DIR}/specs/xml/vk.xml"
     "--dst" "${CMAKE_CURRENT_BINARY_DIR}/vk.hpp"
+    "--icd" "${CMAKE_CURRENT_BINARY_DIR}/icd/vtable.hpp"
     "--dispatch" "${CMAKE_CURRENT_BINARY_DIR}/icd/dispatch.cpp"
     "--platform" "${VK_PLATFORM}"
 DEPENDS
@@ -61,6 +63,7 @@ endif()
 
 ##-----------------------------------------------------------------------------
 add_library (cruft-vk-icd STATIC
+    ${CMAKE_CURRENT_BINARY_DIR}/icd/vtable.hpp
     ${CMAKE_CURRENT_BINARY_DIR}/icd/dispatch.cpp
     icd/vendor.hpp
     icd/vendor.cpp

tools/spec.py

@@ -69,9 +69,15 @@ class type(object):
     This includes (but is not limited to) types, like structures; and values,
     like constants.
     """
-    def __init__(self, name:str, depends:List[str] = []):
+    def __init__(self, name:str, depends:List[str] = None):
+        assert name
+
         self.name = name
-        self.depends = [] + depends
+        self.depends = depends or []
+
+        assert isinstance(self.depends, list)
+        for i in self.depends:
+            assert isinstance(i, str)
 
     def depends(self):
         return self.depends
@@ -85,18 +91,28 @@ class type(object):
 
 ###############################################################################
 class aliastype(type):
-    def __init__(self, name:str, target:str):
+    """
-        super().__init__(name, depends=[target])
+    A type that is an alias for another type.
+
+    May be serialised using an appropriate host language facility
+    (eg, a typedef)
+    """
+    def __init__(self, name:str, target:str, depends:List[str]=None):
+        depends = depends or []
+        super().__init__(name, depends=depends+[target])
         self.target = target
 
     def declare(self):
-        return "using %(name)s = %(target)s;" % {
+        return f"using {rename(self.name)} = {rename(self.target)};"
-            "name": self.name,
-            "target": self.target
-        }
 
 
+##-----------------------------------------------------------------------------
 class aliasvalue(type):
+    """
+    A value that is an alias for another value.
+
+    May be serialised using an appropriate host language facility.
+    """
     def __init__(self, name:str, target:str):
         super().__init__(name, depends=[target])
         self.target = target
@@ -104,8 +120,8 @@ class aliasvalue(type):
 
     def declare(self):
         return "constexpr auto %(name)s = %(target)s;" % {
-            "name": self.name,
+            "name": rename(self.name),
-            "target": self.target
+            "target": rename(self.target),
         }
 
 
@@ -369,6 +385,21 @@ class constant(type):
 
 
 class command(type):
+    class param(type):
+        def __init__(self, node, **kwargs):
+            assert node.tag == 'param'
+
+            super().__init__(
+                name = node.find('name').text,
+                depends=[node.find('type').text],
+                **kwargs
+            )
+
+            self.type = ""
+            for i in node.iter():
+                self.type += i.text or ""
+                self.type += i.tail or ""
+
     def __init__(self, node):
         assert node.tag == "command"
         proto = node.find('proto')
@@ -376,20 +407,16 @@ class command(type):
         super().__init__(name)
 
         self.result = proto.find('type').text
+        self.params = [self.param(p) for p in node.findall('./param')]
         self.depends += [self.result]
-
+        for p in self.params:
-        self.params = []
+            self.depends += p.depends
-        for p in node.findall('./param'):
-            self.depends.append(p.find('type').text)
-            self.params.append("".join(p.itertext()))
-
-        pass
 
     def declare(self):
         return "%(result)s %(name)s (%(params)s) noexcept;" % {
             'name': rename(self.name),
             'result': self.result,
-            'params': ", ".join(self.params)
+            'params': ", ".join(p.type for p in self.params)
         }
 
 
@@ -652,6 +679,7 @@ if __name__ == '__main__':
     parser = argparse.ArgumentParser(description='Transform XML API specification into C++ headers')
     parser.add_argument('--src', type=str, help='the path to the XML file to transform')
     parser.add_argument('--dst', type=str, help='the output path for the result')
+    parser.add_argument('--icd', type=str, help='the output path for the icd loading routines')
     parser.add_argument('--dispatch', type=str, help="the output path for function dispatch")
     parser.add_argument(
         '--platform',
@@ -700,19 +728,44 @@ if __name__ == '__main__':
             dst.write('\n')
         dst.write('}\n')
 
+    with open(args.icd, 'w') as icd:
+        icd.write("""
+        #include "vk.hpp"
+
+        namespace cruft::vk::icd {
+        struct vtable {
+        """)
+
+        for obj in q:
+            if not isinstance(obj, command):
+                continue
+            icd.write(f"{obj.result} (*{obj.name}) ({','.join(p.type for p in obj.params)});\n")
+
+        icd.write("""
+        };
+        }
+        """)
+
+
     with open(args.dispatch, 'w') as dispatch:
         dispatch.write("""
         #include "vk.hpp"
+        #include "vtable.hpp"
+
         #include <cruft/util/debug.hpp>
 
         #pragma GCC diagnostic ignored "-Wunused-parameter"
+
+        static cruft::vk::icd::vtable *s_vtable = nullptr;
         """)
+
+
         for obj in q:
             if not isinstance(obj, command):
                 continue
 
             dispatch.write(f"""
-            extern "C" {obj.result} {rename(obj.name)} ({", ".join(obj.params)}) noexcept {{
+            extern "C" {obj.result} {rename(obj.name)} ({", ".join(p.type for p in obj.params)}) noexcept {{
-                unimplemented ();
+                return (*s_vtable->{obj.name})({", ".join(p.name for p in obj.params)});
             }}
             """)