LuaJIT: Clean up code and organization.

src/LuaJITEngine.cpp

@@ -1,28 +1,6 @@
 #include "ScriptEngine.hpp"
 #include <luajit-2.0/lua.hpp>
 
-static const luaL_Reg lj_lib_load[] = {
-    { "",              luaopen_base },
-    { LUA_LOADLIBNAME, luaopen_package },
-    { LUA_TABLIBNAME,  luaopen_table },
-    { LUA_STRLIBNAME,  luaopen_string },
-    { LUA_MATHLIBNAME, luaopen_math },
-    { LUA_BITLIBNAME,  luaopen_bit },
-    { LUA_JITLIBNAME,  luaopen_jit },
-    { LUA_FFILIBNAME,  luaopen_ffi },
-    { NULL,            NULL }
-};
-
-LUALIB_API void custom_openlibs(lua_State *L)
-{
-    const luaL_Reg *lib;
-    for (lib = lj_lib_load; lib->func; lib++) {
-    	lua_pushcfunction(L, lib->func);
-    	lua_pushstring(L, lib->name);
-    	lua_call(L, 1, 0);
-  	}
-  	lua_pop(L, 1);
-}
 
 struct LuaJITEngine : ScriptEngine {
 	lua_State* L = NULL;
@@ -33,15 +11,15 @@ struct LuaJITEngine : ScriptEngine {
 		float sampleRate;
 		float sampleTime;
 		int bufferSize;
-		float* inputs[NUM_ROWS+1];
-		float* outputs[NUM_ROWS+1];
+		float* inputs[NUM_ROWS + 1];
+		float* outputs[NUM_ROWS + 1];
 		float* knobs;
 		bool* switches;
-		float* lights[NUM_ROWS+1];
-		float* switchLights[NUM_ROWS+1];
+		float* lights[NUM_ROWS + 1];
+		float* switchLights[NUM_ROWS + 1];
 	};
 
-	LuaProcessBlock block;
+	LuaProcessBlock luaBlock;
 
 	~LuaJITEngine() {
 		if (L)
@@ -53,22 +31,21 @@ struct LuaJITEngine : ScriptEngine {
 	}
 
 	int run(const std::string& path, const std::string& script) override {
-		ProcessBlock* original_block = getProcessBlock();
-
-		block.sampleRate = original_block->sampleRate;
-		block.sampleTime = original_block->sampleTime;
-		block.bufferSize = original_block->bufferSize;
+		ProcessBlock* block = getProcessBlock();
 
 		// Initialize all the pointers with an offset of -1
-		block.knobs = (float*)&(original_block->knobs[-1]);
-		block.switches = (bool*)&(original_block->switches[-1]);
-
-		for(int i = 1; i < NUM_ROWS + 1; i++) {
-			block.inputs[i] = (float*)&(original_block->inputs[i-1][-1]);
-			block.outputs[i] = (float*)&(original_block->outputs[i-1][-1]);
-			block.lights[i] = (float*)&(original_block->lights[i-1][-1]);
-			block.switchLights[i] = (float*)&(original_block->switchLights[i-1][-1]);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+		luaBlock.knobs = &block->knobs[-1];
+		luaBlock.switches = &block->switches[-1];
+
+		for (int i = 0; i < NUM_ROWS; i++) {
+			luaBlock.inputs[i + 1] = &block->inputs[i][-1];
+			luaBlock.outputs[i + 1] = &block->outputs[i][-1];
+			luaBlock.lights[i + 1] = &block->lights[i][-1];
+			luaBlock.switchLights[i + 1] = &block->switchLights[i][-1];
 		}
+#pragma GCC diagnostic pop
 
 		L = luaL_newstate();
 		if (!L) {
@@ -77,7 +54,22 @@ struct LuaJITEngine : ScriptEngine {
 		}
 
 		// Import a subset of the standard library
-		custom_openlibs(L);
+		static const luaL_Reg lj_lib_load[] = {
+			{"",              luaopen_base},
+			{LUA_LOADLIBNAME, luaopen_package},
+			{LUA_TABLIBNAME,  luaopen_table},
+			{LUA_STRLIBNAME,  luaopen_string},
+			{LUA_MATHLIBNAME, luaopen_math},
+			{LUA_BITLIBNAME,  luaopen_bit},
+			{LUA_JITLIBNAME,  luaopen_jit},
+			{LUA_FFILIBNAME,  luaopen_ffi},
+			{NULL,            NULL}
+		};
+		for (const luaL_Reg* lib = lj_lib_load; lib->func; lib++) {
+			lua_pushcfunction(L, lib->func);
+			lua_pushstring(L, lib->name);
+			lua_call(L, 1, 0);
+		}
 
 		// Set user pointer
 		lua_pushlightuserdata(L, this);
@@ -102,11 +94,11 @@ struct LuaJITEngine : ScriptEngine {
 		}
 		lua_setglobal(L, "config");
 
-		// Loads the FFI auxiliary functions.
+		// Load the FFI auxiliary functions.
 		std::stringstream ffi_stream;
 		ffi_stream
 		<< "local ffi = require('ffi')" << std::endl
-		// Describes the struct 'LuaProcessBlock' that way LuaJIT knows how to access the data
+		// Describe the struct `LuaProcessBlock` so that LuaJIT knows how to access the data
 		<< "ffi.cdef[[" << std::endl
 		<< "struct LuaProcessBlock {" << std::endl
 		<< "float sampleRate;" << std::endl
@@ -118,9 +110,9 @@ struct LuaJITEngine : ScriptEngine {
 		<< "bool *switches;" << std::endl
 		<< "float *lights[" << NUM_ROWS + 1 << "];" << std::endl
 		<< "float *switchLights[" << NUM_ROWS + 1 << "];" << std::endl
-		<<"};]]" << std::endl
-		// Declares the function 'castBlock' used to transform the 'block' pointer into a LuaJIT cdata
-		<< "function castBlock(b) return ffi.cast('struct LuaProcessBlock*', b) end";
+		<< "};]]" << std::endl
+		// Declare the function `_castBlock` used to transform `luaBlock` pointer into a LuaJIT cdata
+		<< "function _castBlock(b) return ffi.cast('struct LuaProcessBlock*', b) end";
 		std::string ffi_script = ffi_stream.str();
 
 		// Compile the ffi script
@@ -183,21 +175,27 @@ struct LuaJITEngine : ScriptEngine {
 		}
 
 		// Create block object
-        lua_getglobal(L, "castBlock");
-        lua_pushlightuserdata(L, (void *)&block);
-        if (lua_pcall(L, 1, 1, 0) != 0)
-            printf("error running function 'castBlock': %s", lua_tostring(L, -1));
+		lua_getglobal(L, "_castBlock");
+		lua_pushlightuserdata(L, (void*) &luaBlock);
+		if (lua_pcall(L, 1, 1, 0)) {
+			const char* s = lua_tostring(L, -1);
+			WARN("LuaJIT: Error casting block: %s", s);
+			display(s);
+			lua_pop(L, 1);
+			return -1;
+		}
 
 		return 0;
 	}
 
 	int process() override {
-		ProcessBlock* original_block = getProcessBlock();
+		ProcessBlock* block = getProcessBlock();
 
-		// Update the values of the block (the pointers should not change)
-		block.sampleRate = original_block->sampleRate;
-		block.sampleTime = original_block->sampleTime;
-		block.bufferSize = original_block->bufferSize;
+		// Update the values of the block.
+		// The pointer values do not change.
+		luaBlock.sampleRate = block->sampleRate;
+		luaBlock.sampleTime = block->sampleTime;
+		luaBlock.bufferSize = block->bufferSize;
 
 		// Duplicate process function
 		lua_pushvalue(L, -2);