Fix: Main function of native modules were NULL (#161)

This is handled and the crash were fixed

src/pk_compiler.c

@@ -2766,7 +2766,7 @@ static void compileTopLevelStatement(Compiler* compiler) {
 }
 
 PkResult compile(PKVM* vm, Script* script, const char* source,
-             const PkCompileOptions* options) {
+                 const PkCompileOptions* options) {
 
   // Skip utf8 BOM if there is any.
   if (strncmp(source, "\xEF\xBB\xBF", 3) == 0) source += 3;
@@ -2781,10 +2781,14 @@ PkResult compile(PKVM* vm, Script* script, const char* source,
   compiler->next_compiler = vm->compiler;
   vm->compiler = compiler;
 
+  // If the script doesn't has a body by default, it's probably was created by
+  // the native api function (pkNewModule() that'll return a module without a
+  // main function) so just create and add the function here.
+  if (script->body == NULL) scriptAddMain(vm, script);
+
   // If we're compiling for a script that was already compiled (when running
   // REPL or evaluating an expression) we don't need the old main anymore.
   // just use the globals and functions of the script and use a new body func.
-  ASSERT(script->body != NULL, OOPS);
   pkByteBufferClear(&script->body->fn->opcodes, vm);
 
   // Remember the count of the globals, functions and types, If the compilation

src/pk_core.c

@@ -38,7 +38,7 @@
 
 // Create a new module with the given [name] and returns as a Script* for
 // internal. Which will be wrapped by pkNewModule to return a pkHandle*.
-static Script* newModuleInternal(PKVM* vm, const char* name, bool is_core);
+static Script* newModuleInternal(PKVM* vm, const char* name);
 
 // The internal function to add global value to a module.
 static void moduleAddGlobalInternal(PKVM* vm, Script* script,
@@ -51,7 +51,7 @@ static void moduleAddFunctionInternal(PKVM* vm, Script* script,
 
 // pkNewModule implementation (see pocketlang.h for description).
 PkHandle* pkNewModule(PKVM* vm, const char* name) {
-  Script* module = newModuleInternal(vm, name, false);
+  Script* module = newModuleInternal(vm, name);
   return vmNewHandle(vm, VAR_OBJ(module));
 }
 
@@ -743,7 +743,7 @@ DEF(coreMapRemove,
 /*****************************************************************************/
 
 // Create a module and add it to the vm's core modules, returns the script.
-static Script* newModuleInternal(PKVM* vm, const char* name, bool is_core) {
+static Script* newModuleInternal(PKVM* vm, const char* name) {
 
   // Create a new Script for the module.
   String* _name = newString(vm, name);
@@ -757,7 +757,7 @@ static Script* newModuleInternal(PKVM* vm, const char* name, bool is_core) {
              "A module named '$' already exists", name)->data);
   }
 
-  Script* scr = newScript(vm, _name, is_core);
+  Script* scr = newScript(vm, _name, true);
   vmPopTempRef(vm); // _name
 
   // Add the script to core_libs.
@@ -1182,7 +1182,7 @@ void initializeCore(PKVM* vm) {
 
   // Core Modules /////////////////////////////////////////////////////////////
 
-  Script* lang = newModuleInternal(vm, "lang", true);
+  Script* lang = newModuleInternal(vm, "lang");
   MODULE_ADD_FN(lang, "clock", stdLangClock,  0);
   MODULE_ADD_FN(lang, "gc",    stdLangGC,     0);
   MODULE_ADD_FN(lang, "disas", stdLangDisas,  1);
@@ -1191,7 +1191,7 @@ void initializeCore(PKVM* vm) {
   MODULE_ADD_FN(lang, "debug_break", stdLangDebugBreak, 0);
 #endif
 
-  Script* math = newModuleInternal(vm, "math", true);
+  Script* math = newModuleInternal(vm, "math");
   MODULE_ADD_FN(math, "floor", stdMathFloor,       1);
   MODULE_ADD_FN(math, "ceil",  stdMathCeil,        1);
   MODULE_ADD_FN(math, "pow",   stdMathPow,         2);
@@ -1218,7 +1218,7 @@ void initializeCore(PKVM* vm) {
   // attribute of a core module and we can throw an error.
   moduleAddGlobalInternal(vm, math, "PI", VAR_NUM(M_PI));
 
-  Script* fiber = newModuleInternal(vm, "Fiber", true);
+  Script* fiber = newModuleInternal(vm, "Fiber");
   MODULE_ADD_FN(fiber, "new",      stdFiberNew,     1);
   MODULE_ADD_FN(fiber, "run",      stdFiberRun,    -1);
   MODULE_ADD_FN(fiber, "resume",   stdFiberResume, -1);

src/pk_var.c

@@ -375,15 +375,11 @@ Script* newScript(PKVM* vm, String* name, bool is_core) {
 
   script->path = name;
   script->module = NULL;
-  script->initialized = false;
+  script->initialized = is_core;
   script->body = NULL;
 
-  // Core modules has its name as the module name, and since they don't have a
+  // Core modules has its name as the module name.
-  // main function, they doesn't need an initialization.
+  if (is_core) script->module = name;
-  if (is_core) {
-    script->module = name;
-    script->initialized = true;
-  }
 
   pkVarBufferInit(&script->globals);
   pkUintBufferInit(&script->global_names);
@@ -396,10 +392,7 @@ Script* newScript(PKVM* vm, String* name, bool is_core) {
   // if it's not a core module.
   if (!is_core) {
     vmPushTempRef(vm, &script->_super);
-    const char* fn_name = PK_IMPLICIT_MAIN_NAME;
+    scriptAddMain(vm, script);
-    script->body = newFunction(vm, fn_name, (int)strlen(fn_name),
-                               script, false, NULL/*TODO*/);
-    script->body->arity = 0;
 
     // Add '__file__' variable with it's path as value. If the path starts with
     // '$' It's a special file ($(REPL) or $(TRY)) and don't define __file__.
@@ -1159,6 +1152,16 @@ uint32_t scriptAddGlobal(PKVM* vm, Script* script,
   return script->globals.count - 1;
 }
 
+void scriptAddMain(PKVM* vm, Script* script) {
+  ASSERT(script->body == NULL, OOPS);
+
+  const char* fn_name = PK_IMPLICIT_MAIN_NAME;
+  script->body = newFunction(vm, fn_name, (int)strlen(fn_name),
+                             script, false, NULL/*TODO*/);
+  script->body->arity = 0;
+  script->initialized = false;
+}
+
 bool instGetAttrib(PKVM* vm, Instance* inst, String* attrib, Var* value) {
   ASSERT(inst != NULL, OOPS);
   ASSERT(attrib != NULL, OOPS);

src/pk_var.h

@@ -295,7 +295,11 @@ struct Script {
   pkVarBuffer literals;        //< Script literal constant values.
 
   Function* body;              //< Script body is an anonymous function.
-  bool initialized;            //< Set to true just before the body executed.
+
+  // When a script has globals, it's body need to be executed to initialize the
+  // global values, this will be false if the module isn't initialized yet and
+  // we need to execute the script's body whe we're importing it.
+  bool initialized;
 };
 
 // Script function pointer.
@@ -588,6 +592,12 @@ uint32_t scriptAddGlobal(PKVM* vm, Script* script,
                          const char* name, uint32_t length,
                          Var value);
 
+// This will allocate a new implicit main function for the script and assign to
+// the script's body attribute. And the attribute initialized will be set to
+// false for the new function. Note that the body of the script should be NULL
+// before calling this function.
+void scriptAddMain(PKVM* vm, Script* script);
+
 // Get the attribut from the instance and set it [value]. On success return
 // true, if the attribute not exists it'll return false but won't set an error.
 bool instGetAttrib(PKVM* vm, Instance* inst, String* attrib, Var* value);