Allow 'continue' inside 'try' clause
SF patch 102989 by Thomas Wouters
diff --git a/Python/ceval.c b/Python/ceval.c
index 8eaa8bd..264ba30 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -322,7 +322,8 @@
WHY_EXCEPTION, /* Exception occurred */
WHY_RERAISE, /* Exception re-raised by 'finally' */
WHY_RETURN, /* 'return' statement */
- WHY_BREAK /* 'break' statement */
+ WHY_BREAK, /* 'break' statement */
+ WHY_CONTINUE, /* 'continue' statement */
};
static enum why_code do_raise(PyObject *, PyObject *, PyObject *);
@@ -1357,6 +1358,11 @@
case BREAK_LOOP:
why = WHY_BREAK;
break;
+
+ case CONTINUE_LOOP:
+ retval = PyInt_FromLong(oparg);
+ why = WHY_CONTINUE;
+ break;
case RAISE_VARARGS:
u = v = w = NULL;
@@ -1419,7 +1425,8 @@
v = POP();
if (PyInt_Check(v)) {
why = (enum why_code) PyInt_AsLong(v);
- if (why == WHY_RETURN)
+ if (why == WHY_RETURN ||
+ why == CONTINUE_LOOP)
retval = POP();
}
else if (PyString_Check(v) || PyClass_Check(v)) {
@@ -1834,7 +1841,7 @@
case SETUP_EXCEPT:
case SETUP_FINALLY:
PyFrame_BlockSetup(f, opcode, INSTR_OFFSET() + oparg,
- STACK_LEVEL());
+ STACK_LEVEL());
continue;
case SET_LINENO:
@@ -2110,6 +2117,18 @@
while (why != WHY_NOT && f->f_iblock > 0) {
PyTryBlock *b = PyFrame_BlockPop(f);
+
+ if (b->b_type == SETUP_LOOP && why == WHY_CONTINUE) {
+ /* For a continue inside a try block,
+ don't pop the block for the loop. */
+ PyFrame_BlockSetup(f, b->b_type, b->b_level,
+ b->b_handler);
+ why = WHY_NOT;
+ JUMPTO(PyInt_AS_LONG(retval));
+ Py_DECREF(retval);
+ break;
+ }
+
while (STACK_LEVEL() > b->b_level) {
v = POP();
Py_XDECREF(v);
@@ -2145,7 +2164,8 @@
PUSH(exc);
}
else {
- if (why == WHY_RETURN)
+ if (why == WHY_RETURN ||
+ why == CONTINUE_LOOP)
PUSH(retval);
v = PyInt_FromLong((long)why);
PUSH(v);
diff --git a/Python/compile.c b/Python/compile.c
index 68f9e7f..3dae4c8 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -5,7 +5,7 @@
XXX add __doc__ attribute == co_doc to code object attributes?
XXX (it's currently the first item of the co_const tuple)
XXX Generate simple jump for break/return outside 'try...finally'
- XXX Allow 'continue' inside try-finally
+ XXX Allow 'continue' inside finally clause of try-finally
XXX New opcode for loading the initial index for a for loop
XXX other JAR tricks?
*/
@@ -3247,19 +3247,24 @@
}
else {
int j;
- for (j = 0; j <= i; ++j) {
+ for (j = i-1; j >= 0; --j) {
if (c->c_block[j] == SETUP_LOOP)
break;
}
- if (j < i+1) {
+ if (j >= 0) {
/* there is a loop, but something interferes */
- for (++j; j <= i; ++j) {
- if (c->c_block[i] == SETUP_EXCEPT
- || c->c_block[i] == SETUP_FINALLY) {
- com_error(c, PyExc_SyntaxError,
- "'continue' not supported inside 'try' clause");
+ for (; i > j; --i) {
+ if (c->c_block[i] == SETUP_EXCEPT ||
+ c->c_block[i] == SETUP_FINALLY) {
+ com_addoparg(c, CONTINUE_LOOP,
+ c->c_begin);
return;
}
+ if (c->c_block[i] == END_FINALLY) {
+ com_error(c, PyExc_SyntaxError,
+ "'continue' not supported inside 'finally' clause");
+ return;
+ }
}
}
com_error(c, PyExc_SyntaxError,