Fix computation of stack depth for classdef and closures.

Also minor tweaks to internal routines.
Use PyCF_MASK instead of explicit list of flags.

For the MAKE_CLOSURE opcode, the number of items popped off the stack
depends on both the oparg and the number of free variables for the
code object.  Fix the code so it accounts for the free variables.

In com_classdef(), record an extra pop to account for the STORE call
after the BUILD_CLASS.

Get rid of some commented out debugging code in com_push() and
com_pop().

Factor string resize logic into helper routine com_check_size().

In com_addbyte(), remove redudant if statement after assert.  (They
test the same condition.)

In several routines, use string macros instead of string functions.

Python/compile.c

@@ -668,20 +668,21 @@ static void
 com_push(struct compiling *c, int n)
 {
 	c->c_stacklevel += n;
-	if (c->c_stacklevel > c->c_maxstacklevel)
+	if (c->c_stacklevel > c->c_maxstacklevel) {
 		c->c_maxstacklevel = c->c_stacklevel;
+		/*
+		fprintf(stderr, "%s:%s:%d max stack nexti=%d level=%d n=%d\n",
+			c->c_filename, c->c_name, c->c_lineno,
+			c->c_nexti, c->c_stacklevel, n);
+		*/
+	}
 }
 
 static void
 com_pop(struct compiling *c, int n)
 {
-	if (c->c_stacklevel < n) {
-		/* fprintf(stderr,
-			"%s:%d: underflow! nexti=%d, level=%d, n=%d\n",
-			c->c_filename, c->c_lineno,
-			c->c_nexti, c->c_stacklevel, n); */
+	if (c->c_stacklevel < n) 
 		c->c_stacklevel = 0;
-	}
 	else
 		c->c_stacklevel -= n;
 }
@@ -695,26 +696,26 @@ com_done(struct compiling *c)
 		_PyString_Resize(&c->c_lnotab, c->c_lnotab_next);
 }
 
+static int
+com_check_size(PyObject **s, int offset)
+{
+	int len = PyString_GET_SIZE(*s);
+	if (offset >= len) 
+		return _PyString_Resize(s, len * 2);
+	return 0;
+}
+
 static void
 com_addbyte(struct compiling *c, int byte)
 {
-	int len;
 	/*fprintf(stderr, "%3d: %3d\n", c->c_nexti, byte);*/
 	assert(byte >= 0 && byte <= 255);
-	if (byte < 0 || byte > 255) {
-		com_error(c, PyExc_SystemError,
-			  "com_addbyte: byte out of range");
-	}
-	if (c->c_code == NULL)
+	assert(c->c_code);
+	if (com_check_size(&c->c_code, c->c_nexti)) {
+		c->c_errors++;
 		return;
-	len = PyString_Size(c->c_code);
-	if (c->c_nexti >= len) {
-		if (_PyString_Resize(&c->c_code, len+1000) != 0) {
-			c->c_errors++;
-			return;
-		}
 	}
-	PyString_AsString(c->c_code)[c->c_nexti++] = byte;
+	PyString_AS_STRING(c->c_code)[c->c_nexti++] = byte;
 }
 
 static void
@@ -727,18 +728,14 @@ com_addint(struct compiling *c, int x)
 static void
 com_add_lnotab(struct compiling *c, int addr, int line)
 {
-	int size;
 	char *p;
 	if (c->c_lnotab == NULL)
 		return;
-	size = PyString_Size(c->c_lnotab);
-	if (c->c_lnotab_next+2 > size) {
-		if (_PyString_Resize(&c->c_lnotab, size + 1000) < 0) {
-			c->c_errors++;
-			return;
-		}
+	if (com_check_size(&c->c_lnotab, c->c_lnotab_next + 2)) {
+		c->c_errors++;
+		return;
 	}
-	p = PyString_AsString(c->c_lnotab) + c->c_lnotab_next;
+	p = PyString_AS_STRING(c->c_lnotab) + c->c_lnotab_next;
 	*p++ = addr;
 	*p++ = line;
 	c->c_lnotab_next += 2;
@@ -804,7 +801,7 @@ com_addfwref(struct compiling *c, int op, int *p_anchor)
 static void
 com_backpatch(struct compiling *c, int anchor)
 {
-	unsigned char *code = (unsigned char *) PyString_AsString(c->c_code);
+	unsigned char *code = (unsigned char *) PyString_AS_STRING(c->c_code);
 	int target = c->c_nexti;
 	int dist;
 	int prev;
@@ -2326,26 +2323,27 @@ com_test(struct compiling *c, node *n)
 {
 	REQ(n, test); /* and_test ('or' and_test)* | lambdef */
 	if (NCH(n) == 1 && TYPE(CHILD(n, 0)) == lambdef) {
-		PyObject *co;
+		PyCodeObject *co;
 		int i, closure;
 		int ndefs = com_argdefs(c, CHILD(n, 0));
 		symtable_enter_scope(c->c_symtable, "lambda", lambdef,
 				     n->n_lineno);
-		co = (PyObject *) icompile(CHILD(n, 0), c);
+		co = icompile(CHILD(n, 0), c);
 		if (co == NULL) {
 			c->c_errors++;
 			return;
 		}
 		symtable_exit_scope(c->c_symtable);
-		i = com_addconst(c, co);
-		closure = com_make_closure(c, (PyCodeObject *)co);
-		Py_DECREF(co);
+		i = com_addconst(c, (PyObject *)co);
+		closure = com_make_closure(c, co);
 		com_addoparg(c, LOAD_CONST, i);
 		com_push(c, 1);
-		if (closure)
+		if (closure) {
 			com_addoparg(c, MAKE_CLOSURE, ndefs);
-		else
+			com_pop(c, PyTuple_GET_SIZE(co->co_freevars));
+		} else
 			com_addoparg(c, MAKE_FUNCTION, ndefs);
+		Py_DECREF(co);
 		com_pop(c, ndefs);
 	}
 	else {
@@ -3564,7 +3562,8 @@ static void
 com_classdef(struct compiling *c, node *n)
 {
 	int i;
-	PyObject *co, *v;
+	PyObject *v;
+	PyCodeObject *co;
 	char *name;
 
 	REQ(n, classdef);
@@ -3587,23 +3586,25 @@ com_classdef(struct compiling *c, node *n)
 		com_bases(c, CHILD(n, 3));
 	name = STR(CHILD(n, 1));
 	symtable_enter_scope(c->c_symtable, name, TYPE(n), n->n_lineno);
-	co = (PyObject *)icompile(n, c);
+	co = icompile(n, c);
 	symtable_exit_scope(c->c_symtable);
 	if (co == NULL)
 		c->c_errors++;
 	else {
-		int closure = com_make_closure(c, (PyCodeObject *)co);
-		i = com_addconst(c, co);
+		int closure = com_make_closure(c, co);
+		i = com_addconst(c, (PyObject *)co);
 		com_addoparg(c, LOAD_CONST, i);
 		com_push(c, 1);
-		if (closure)
+		if (closure) {
 			com_addoparg(c, MAKE_CLOSURE, 0);
-		else
+			com_pop(c, PyTuple_GET_SIZE(co->co_freevars));
+		} else
 			com_addoparg(c, MAKE_FUNCTION, 0);
 		com_addoparg(c, CALL_FUNCTION, 0);
 		com_addbyte(c, BUILD_CLASS);
 		com_pop(c, 2);
 		com_addop_varname(c, VAR_STORE, STR(CHILD(n, 1)));
+		com_pop(c, 1);
 		Py_DECREF(co);
 	}
 }
@@ -4082,8 +4083,7 @@ jcompile(node *n, char *filename, struct compiling *base,
 		if (base->c_nested 
 		    || (sc.c_symtable->st_cur->ste_type == TYPE_FUNCTION))
 			sc.c_nested = 1;
-		sc.c_flags |= base->c_flags & (CO_GENERATOR_ALLOWED |
-					       CO_FUTURE_DIVISION);
+		sc.c_flags |= base->c_flags & PyCF_MASK;
 	} else {
 		sc.c_private = NULL;
 		sc.c_future = PyNode_Future(n, filename);