SF bug #436207: "if 0: yield x" is ignored.
Not anymore <wink>. Pure hack. Doesn't fix any other "if 0:" glitches.
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index 884cbc0..3646001 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -431,6 +431,9 @@
Try writing it without generators, and correctly, and without generating
3 internal results for each result output.
+XXX Suspect there's memory leaks in this one; definitely in the next
+XXX version.
+
>>> def times(n, g):
... for i in g:
... yield n * i
@@ -482,6 +485,8 @@
functions can be reused as-is, because they only assume their stream
arguments are iterable -- a LazyList is the same as a generator to times().
+XXX Massive memory leaks in this; see Python-Iterators.
+
>>> class LazyList:
... def __init__(self, g):
... self.sofar = []
@@ -514,7 +519,8 @@
[400, 405, 432, 450, 480, 486, 500, 512, 540, 576, 600, 625, 640, 648, 675]
"""
-# syntax_tests mostly provokes SyntaxErrors.
+# syntax_tests mostly provokes SyntaxErrors. Also fiddling with #if 0
+# hackery.
syntax_tests = """
@@ -588,13 +594,128 @@
... return
>>> list(f())
[12, 666]
+
+>>> def f():
+... if 0:
+... yield 1
+>>> type(f())
+<type 'generator'>
+
+>>> def f():
+... if "":
+... yield None
+>>> type(f())
+<type 'generator'>
+
+>>> def f():
+... return
+... try:
+... if x==4:
+... pass
+... elif 0:
+... try:
+... 1/0
+... except SyntaxError:
+... pass
+... else:
+... if 0:
+... while 12:
+... x += 1
+... yield 2 # don't blink
+... f(a, b, c, d, e)
+... else:
+... pass
+... except:
+... x = 1
+... return
+>>> type(f())
+<type 'generator'>
+
+>>> def f():
+... if 0:
+... def g():
+... yield 1
+...
+>>> type(f())
+<type 'None'>
+
+>>> def f():
+... if 0:
+... class C:
+... def __init__(self):
+... yield 1
+... def f(self):
+... yield 2
+>>> type(f())
+<type 'None'>
"""
-__test__ = {"tut": tutorial_tests,
- "pep": pep_tests,
- "email": email_tests,
- "fun": fun_tests,
- "syntax": syntax_tests}
+
+x_tests = """
+
+>>> def firstn(g, n):
+... return [g.next() for i in range(n)]
+
+>>> def times(n, g):
+... for i in g:
+... yield n * i
+
+>>> def merge(g, h):
+... ng = g.next()
+... nh = h.next()
+... while 1:
+... if ng < nh:
+... yield ng
+... ng = g.next()
+... elif ng > nh:
+... yield nh
+... nh = h.next()
+... else:
+... yield ng
+... ng = g.next()
+... nh = h.next()
+
+>>> class LazyList:
+... def __init__(self, g):
+... self.sofar = []
+... self.fetch = g.next
+...
+... def __getitem__(self, i):
+... sofar, fetch = self.sofar, self.fetch
+... while i >= len(sofar):
+... sofar.append(fetch())
+... return sofar[i]
+
+>>> def m235():
+... yield 1
+... # Gack: m235 below actually refers to a LazyList.
+... me_times2 = times(2, m235)
+... me_times3 = times(3, m235)
+... me_times5 = times(5, m235)
+... for i in merge(merge(me_times2,
+... me_times3),
+... me_times5):
+... yield i
+
+>>> m235 = LazyList(m235())
+>>> for i in range(5):
+... x = [m235[j] for j in range(15*i, 15*(i+1))]
+
+
+[1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24]
+[25, 27, 30, 32, 36, 40, 45, 48, 50, 54, 60, 64, 72, 75, 80]
+[81, 90, 96, 100, 108, 120, 125, 128, 135, 144, 150, 160, 162, 180, 192]
+[200, 216, 225, 240, 243, 250, 256, 270, 288, 300, 320, 324, 360, 375, 384]
+[400, 405, 432, 450, 480, 486, 500, 512, 540, 576, 600, 625, 640, 648, 675]
+"""
+
+__test__ = {"tut": tutorial_tests, # clean
+ "pep": pep_tests, # clean
+ "email": email_tests, # clean
+ "fun": fun_tests, # leaks
+ "syntax": syntax_tests # clean
+ #"x": x_tests
+}
# Magic test name that regrtest.py invokes *after* importing this module.
# This worms around a bootstrap problem.
@@ -605,7 +726,7 @@
if 0:
# Temporary block to help track down leaks. So far, the blame
# has fallen mostly on doctest.
- for i in range(1000):
+ for i in range(5000):
doctest.master = None
doctest.testmod(test_generators)
else:
diff --git a/Python/compile.c b/Python/compile.c
index 2ce7487..e82c34c 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -4840,6 +4840,34 @@
#define symtable_add_use(ST, NAME) symtable_add_def((ST), (NAME), USE)
+/* Look for a yield stmt under n. Return 1 if found, else 0. */
+static int
+look_for_yield(node *n)
+{
+ int i;
+
+ for (i = 0; i < NCH(n); ++i) {
+ node *kid = CHILD(n, i);
+
+ switch (TYPE(kid)) {
+
+ case classdef:
+ case funcdef:
+ /* Stuff in nested functions and classes can't make
+ the parent a generator. */
+ return 0;
+
+ case yield_stmt:
+ return 1;
+
+ default:
+ if (look_for_yield(kid))
+ return 1;
+ }
+ }
+ return 0;
+}
+
static void
symtable_node(struct symtable *st, node *n)
{
@@ -4883,8 +4911,12 @@
}
case if_stmt:
for (i = 0; i + 3 < NCH(n); i += 4) {
- if (is_constant_false(NULL, (CHILD(n, i + 1))))
+ if (is_constant_false(NULL, (CHILD(n, i + 1)))) {
+ if (st->st_cur->ste_generator == 0)
+ st->st_cur->ste_generator =
+ look_for_yield(CHILD(n, i+3));
continue;
+ }
symtable_node(st, CHILD(n, i + 1));
symtable_node(st, CHILD(n, i + 3));
}