Fix for line events in the case:
def f(a):
if a:
print 5
else:
pass
diff --git a/Python/compile.c b/Python/compile.c
index 328c57b..7bbcd62 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -629,7 +629,10 @@
int c_maxstacklevel; /* Maximum stack level */
int c_firstlineno;
PyObject *c_lnotab; /* Table mapping address to line number */
- int c_last_addr, c_last_line, c_lnotab_next;
+ int c_last_addr; /* last op addr seen and recorded in lnotab */
+ int c_last_line; /* last line seen and recorded in lnotab */
+ int c_lnotab_next; /* current length of lnotab */
+ int c_lnotab_last; /* start of last lnotab record added */
char *c_private; /* for private name mangling */
int c_tmpname; /* temporary local name counter */
int c_nested; /* Is block nested funcdef or lamdef? */
@@ -848,6 +851,7 @@
c->c_last_addr = 0;
c->c_last_line = 0;
c->c_lnotab_next = 0;
+ c->c_lnotab_last = 0;
c->c_tmpname = 0;
c->c_nested = 0;
c->c_closure = 0;
@@ -964,6 +968,7 @@
else {
int incr_addr = c->c_nexti - c->c_last_addr;
int incr_line = lineno - c->c_last_line;
+ c->c_lnotab_last = c->c_lnotab_next;
while (incr_addr > 255) {
com_add_lnotab(c, 255, 0);
incr_addr -= 255;
@@ -981,6 +986,27 @@
}
static void
+com_strip_lnotab(struct compiling *c)
+{
+ /* strip the last lnotab entry if no opcode were emitted.
+ * This prevents a line number to be generated on a final
+ * pass, like in the following example:
+ *
+ * if a:
+ * print 5
+ * else:
+ * pass
+ *
+ * Without the fix, a line trace event would be generated
+ * on the pass even if a is true (because of the implicit
+ * return).
+ */
+ if (c->c_nexti == c->c_last_addr && c->c_lnotab_last > 0) {
+ c->c_lnotab_next = c->c_lnotab_last;
+ }
+}
+
+static void
com_addoparg(struct compiling *c, int op, int arg)
{
int extended_arg = arg >> 16;
@@ -4167,6 +4193,7 @@
c->c_infunction = 1;
com_node(c, CHILD(n, 4));
c->c_infunction = 0;
+ com_strip_lnotab(c);
com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
com_push(c, 1);
com_addbyte(c, RETURN_VALUE);
@@ -4218,6 +4245,7 @@
else
(void) com_addconst(c, Py_None);
com_node(c, ch);
+ com_strip_lnotab(c);
com_addbyte(c, LOAD_LOCALS);
com_push(c, 1);
com_addbyte(c, RETURN_VALUE);
@@ -4237,6 +4265,7 @@
n = CHILD(n, 0);
if (TYPE(n) != NEWLINE)
com_node(c, n);
+ com_strip_lnotab(c);
com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
com_push(c, 1);
com_addbyte(c, RETURN_VALUE);
@@ -4246,6 +4275,7 @@
case file_input: /* A whole file, or built-in function exec() */
com_file_input(c, n);
+ com_strip_lnotab(c);
com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
com_push(c, 1);
com_addbyte(c, RETURN_VALUE);