Add basic support for -m argument to interpreter

kuroko.c

@@ -303,8 +303,9 @@ static int modulePaths(void) {
 
 int main(int argc, char * argv[]) {
 	int flags = 0;
+	int moduleAsMain = 0;
 	int opt;
-	while ((opt = getopt(argc, argv, "dgrstMV-:")) != -1) {
+	while ((opt = getopt(argc, argv, "dgm:rstMV-:")) != -1) {
 		switch (opt) {
 			case 'd':
 				/* Disassemble code blocks after compilation. */
@@ -322,6 +323,10 @@ int main(int argc, char * argv[]) {
 				/* Disassemble instructions as they are executed. */
 				flags |= KRK_ENABLE_TRACING;
 				break;
+			case 'm':
+				moduleAsMain = 1;
+				optind--; /* to get us back to optarg */
+				goto _finishArgs;
 			case 'r':
 				enableRline = 0;
 				break;
@@ -338,6 +343,7 @@ int main(int argc, char * argv[]) {
 						"Interpreter options:\n"
 						" -d          Debug output from the bytecode compiler.\n"
 						" -g          Collect garbage on every allocation.\n"
+						" -m mod      Run a module as a script.\n"
 						" -r          Disable complex line editing in the REPL.\n"
 						" -s          Debug output from the scanner/tokenizer.\n"
 						" -t          Disassemble instructions as they are exceuted.\n"
@@ -357,6 +363,7 @@ int main(int argc, char * argv[]) {
 		}
 	}
 
+_finishArgs:
 	krk_initVM(flags);
 
 	/* Attach kuroko.argv - argv[0] will be set to an empty string for the repl */
@@ -383,7 +390,23 @@ int main(int argc, char * argv[]) {
 
 	KrkValue result = INTEGER_VAL(0);
 
-	if (optind == argc) {
+	if (moduleAsMain) {
+		/* This isn't going to do what we want for built-in modules, but I'm not sure
+		 * what we _should_ do for them anyway... let's just leave that as a TODO;
+		 * we do let C modules know they are the __main__ now, so non-built-in
+		 * C modules can still act as scripts if they want... */
+		KrkValue module;
+		krk_push(OBJECT_VAL(krk_copyString("__main__",8)));
+		int out = !krk_loadModule(
+			AS_STRING(AS_LIST(OBJECT_VAL(AS_INSTANCE(argList)->_internal))->values[0]),
+			&module,
+			AS_STRING(krk_peek(0)));
+		if (vm.flags & KRK_HAS_EXCEPTION) {
+			krk_dumpTraceback();
+			krk_resetStack();
+		}
+		return out;
+	} else if (optind == argc) {
 		/* Add builtins for the repl, but hide them from the globals() list. */
 		krk_defineNative(&vm.builtins->fields, "exit", exitFunc);
 		krk_defineNative(&vm.builtins->fields, "paste", paste);

modules/maindemo.krk

@@ -0,0 +1,5 @@
+import kuroko
+if __name__ == '__main__':
+    print("Run as main with args:", kuroko.argv)
+else:
+    print("__name__ =", __name__)

vm.c

@@ -125,15 +125,17 @@ static void dumpStack(CallFrame * frame) {
  * is not None, it will also be printed using safe methods.
  */
 void krk_dumpTraceback() {
-	fprintf(stderr, "Traceback, most recent last:\n");
-	for (size_t i = 0; i <= vm.frameCount - 1; i++) {
-		CallFrame * frame = &vm.frames[i];
-		KrkFunction * function = frame->closure->function;
-		size_t instruction = frame->ip - function->chunk.code - 1;
-		fprintf(stderr, "  File \"%s\", line %d, in %s\n",
-			(function->chunk.filename ? function->chunk.filename->chars : "?"),
-			(int)krk_lineNumber(&function->chunk, instruction),
-			(function->name ? function->name->chars : "(unnamed)"));
+	if (vm.frameCount) {
+		fprintf(stderr, "Traceback, most recent last:\n");
+		for (size_t i = 0; i <= vm.frameCount - 1; i++) {
+			CallFrame * frame = &vm.frames[i];
+			KrkFunction * function = frame->closure->function;
+			size_t instruction = frame->ip - function->chunk.code - 1;
+			fprintf(stderr, "  File \"%s\", line %d, in %s\n",
+				(function->chunk.filename ? function->chunk.filename->chars : "?"),
+				(int)krk_lineNumber(&function->chunk, instruction),
+				(function->name ? function->name->chars : "(unnamed)"));
+		}
 	}
 
 	if (!krk_valuesEqual(vm.currentException,NONE_VAL())) {
@@ -3481,7 +3483,7 @@ static int handleException() {
  * a later search path has a krk source and an earlier search path has a shared
  * object module, the later search path will still win.
  */
-int krk_loadModule(KrkString * name, KrkValue * moduleOut) {
+int krk_loadModule(KrkString * name, KrkValue * moduleOut, KrkString * runAs) {
 	KrkValue modulePaths, modulePathsInternal;
 
 	/* See if the module is already loaded */
@@ -3544,7 +3546,7 @@ int krk_loadModule(KrkString * name, KrkValue * moduleOut) {
 		 * returns to the current call frame; modules should return objects. */
 		int previousExitFrame = vm.exitOnFrame;
 		vm.exitOnFrame = vm.frameCount;
-		*moduleOut = krk_runfile(fileName,1,name->chars,fileName);
+		*moduleOut = krk_runfile(fileName,1,runAs->chars,fileName);
 		vm.exitOnFrame = previousExitFrame;
 		if (!IS_OBJECT(*moduleOut)) {
 			krk_runtimeError(vm.exceptions.importError,
@@ -3585,7 +3587,7 @@ int krk_loadModule(KrkString * name, KrkValue * moduleOut) {
 
 		char * handlerName = AS_CSTRING(krk_peek(0));
 
-		KrkValue (*moduleOnLoad)();
+		KrkValue (*moduleOnLoad)(KrkString * name);
 		void * out = dlsym(dlRef, handlerName);
 		memcpy(&moduleOnLoad,&out,sizeof(out));
 
@@ -3599,7 +3601,7 @@ int krk_loadModule(KrkString * name, KrkValue * moduleOut) {
 
 		krk_pop(); /* onload function */
 
-		*moduleOut = moduleOnLoad();
+		*moduleOut = moduleOnLoad(runAs);
 		if (!IS_INSTANCE(*moduleOut)) {
 			krk_runtimeError(vm.exceptions.importError,
 				"Failed to load module '%s' from '%s'", name->chars, fileName);
@@ -3852,7 +3854,7 @@ static KrkValue run() {
 			case OP_IMPORT: {
 				KrkString * name = READ_STRING(operandWidth);
 				KrkValue module;
-				if (!krk_loadModule(name, &module)) {
+				if (!krk_loadModule(name, &module, name)) {
 					goto _finishException;
 				}
 				break;

vm.h

@@ -151,3 +151,4 @@ extern void krk_finalizeClass(KrkClass * _class);
 extern void krk_dumpTraceback();
 extern KrkInstance * krk_startModule(const char * name);
 extern KrkValue krk_dirObject(int argc, KrkValue argv[]);
+extern int krk_loadModule(KrkString * name, KrkValue * moduleOut, KrkString * runAs);