Initial codegen for LuaState_Call.inc.

src/Bindings/gen_LuaState_Call.lua

@@ -0,0 +1,196 @@
+
+-- gen_LuaState_Call.lua
+
+-- Generates the cLuaState::Call() function templates that are included from LuaState.h
+
+--[[
+The cLuaState::Call() family of functions provides a template-based system for calling any Lua function
+either by name or by reference with almost any number of parameters and return values. This is done by
+providing a number of overloads of the same name with variable number of template-type parameters. To
+separate the arguments from the return values, a special type of cLuaState::cRet is used.
+--]]
+
+
+
+
+print("Generating LuaState_Call.inc...")
+
+
+
+
+-- List of combinations (# params, # returns) to generate:
+local Combinations =
+{
+	-- no return values:
+	{0, 0},
+	{1, 0},
+	{2, 0},
+	{3, 0},
+	{4, 0},
+
+	-- 1 return value:
+	{0, 1},
+	{1, 1},
+	{2, 1},
+	{3, 1},
+	{4, 1},
+	{5, 1},
+	{6, 1},
+	{7, 1},
+	{8, 1},
+	{9, 1},
+	{10, 1},
+
+	-- 2 return values:
+	{0, 2},
+	{1, 2},
+	{2, 2},
+	{3, 2},
+	{4, 2},
+	{5, 2},
+	{6, 2},
+	{7, 2},
+	{8, 2},
+	{9, 2},
+	
+	-- Special combinations:
+	{7, 3},
+	{8, 3},
+	{9, 5},
+}
+
+
+
+
+--- Writes a single overloaded function definition for the specified number of params and returns into f
+--[[
+The format for the generated function is this:
+/** Call the specified 3-param 2-return Lua function:
+Returns true if call succeeded, false if there was an error. */
+template <typename FnT, typename ParamT1, typename ParamT2, typename ParamT3, typename RetT1, typename RetT2>
+bool Call(FnT a_Function, ParamT1 a_Param1, ParamT2 a_Param2, ParamT3 a_Param3, const cLuaState::cRet & a_RetMark, RetT1 & a_Ret1, RetT2 & a_Ret2)
+{
+	UNUSED(a_RetMark);
+	if (!PushFunction(a_Function))
+	{
+		return false;
+	}
+	Push(a_Param1);
+	Push(a_Param2);
+	Push(a_Param3);
+	if (!CallFunction(2))
+	{
+		return false;
+	}
+	GetStackValue(-2, a_Ret1);
+	GetStackValue(-1, a_Ret2);
+	lua_pop(m_LuaState, 2);
+	return true;
+}
+Note especially the negative numbers in GetStackValue() calls.
+--]]
+local function WriteOverload(f, a_NumParams, a_NumReturns)
+	-- Write the function doxy-comments:
+	f:write("/** Call the specified ", a_NumParams, "-param ", a_NumReturns, "-return Lua function:\n")
+	f:write("Returns true if call succeeded, false if there was an error. */\n")
+	
+	-- Write the template <...> line:
+	f:write("template <typename FnT")
+	for i = 1, a_NumParams do
+		f:write(", typename ParamT", i)
+	end
+	if (a_NumReturns > 0) then
+		for i = 1, a_NumReturns do
+			f:write(", typename RetT", i)
+		end
+	end
+	f:write(">\n")
+	
+	-- Write the function signature:
+	f:write("bool Call(")
+	f:write("FnT a_Function")
+	for i = 1, a_NumParams do
+		f:write(", ParamT", i, " a_Param", i)
+	end
+	if (a_NumReturns > 0) then
+		f:write(", const cLuaState::cRet & a_RetMark")
+		for i = 1, a_NumReturns do
+			f:write(", RetT", i, " & a_Ret", i)
+		end
+	end
+	f:write(")\n")
+	
+	-- Common code:
+	f:write("{\n")
+	if (a_NumReturns > 0) then
+		f:write("\tUNUSED(a_RetMark);\n")
+	end
+	f:write("\tif (!PushFunction(a_Function))\n")
+	f:write("\t{\n")
+	f:write("\t\treturn false;\n")
+	f:write("\t}\n")
+	
+	-- Push the params:
+	for i = 1, a_NumParams do
+		f:write("\tPush(a_Param", i, ");\n")
+	end
+	
+	-- Call the function:
+	f:write("\tif (!CallFunction(", a_NumReturns, "))\n")
+	f:write("\t{\n")
+	f:write("\t\treturn false;\n")
+	f:write("\t}\n")
+	
+	-- Get the return values:
+	for i = 1, a_NumReturns do
+		f:write("\tGetStackValue(", -1 - a_NumReturns + i, ", a_Ret", i, ");\n")
+	end
+	
+	-- Pop the returns off the stack, if needed:
+	if (a_NumReturns > 0) then
+		f:write("\tlua_pop(m_LuaState, ", a_NumReturns, ");\n")
+	end
+	
+	-- Everything ok:
+	f:write("\treturn true;\n")
+	f:write("}\n")
+	
+	-- Separate from the next function:
+	f:write("\n\n\n\n\n")
+end
+
+
+
+
+
+local f = assert(io.open("LuaState_Call.inc", "w"))
+
+-- Write file header:
+f:write([[
+// LuaState_Call.inc
+
+// This file is auto-generated by gen_LuaState_Call.lua
+// Make changes to the generator instead of to this file!
+
+// This file contains the various overloads for the cLuaState::Call() function
+// Each overload handles a different number of parameters / return values
+]])
+f:write("\n\n\n\n\n")
+
+-- Write out a template function for each overload:
+for _, combination in ipairs(Combinations) do
+	WriteOverload(f, combination[1], combination[2])
+end
+
+-- Close the generated file
+f:close()
+
+
+
+
+
+print("LuaState_Call.inc generated")
+
+
+
+