Skip to content

gh-109823: Adjust labels in compiler when removing an empty basic block which is a jump target #109839

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Sep 25, 2023
Merged

gh-109823: Adjust labels in compiler when removing an empty basic block which is a jump target #109839

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
29070c5
gh-109823: Adjust labels in compiler when removing an empty basic blo…
iritkatriel Sep 25, 2023
8a33990
add news
iritkatriel Sep 25, 2023
c62fd3b
Merge branch 'main' into gh-109823
iritkatriel Sep 25, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions Lib/test/test_compile.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1272,6 +1272,11 @@ def f():
else:
1 if 1 else 1

def test_remove_empty_basic_block_with_jump_target_label(self):
# See gh-109823
def f(x):
while x:
0 if 1 else 0

@requires_debug_ranges()
class TestSourcePositions(unittest.TestCase):
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2023-09-25-14-28-14.gh-issue-109823.kbVTKF.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Fix bug where compiler does not adjust labels when removing an empty basic
block which is a jump target.
9 changes: 8 additions & 1 deletion Python/flowgraph.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -960,6 +960,7 @@ eliminate_empty_basic_blocks(cfg_builder *g) {
while(g->g_entryblock && g->g_entryblock->b_iused == 0) {
g->g_entryblock = g->g_entryblock->b_next;
}
int next_lbl = get_max_label(g->g_entryblock) + 1;
for (basicblock *b = g->g_entryblock; b != NULL; b = b->b_next) {
assert(b->b_iused > 0);
for (int i = 0; i < b->b_iused; i++) {
Expand All @@ -969,7 +970,13 @@ eliminate_empty_basic_blocks(cfg_builder *g) {
while (target->b_iused == 0) {
target = target->b_next;
}
instr->i_target = target;
if (instr->i_target != target) {
if (!IS_LABEL(target->b_label)) {
target->b_label.id = next_lbl++;
}
instr->i_target = target;
instr->i_oparg = target->b_label.id;
}
assert(instr->i_target && instr->i_target->b_iused > 0);
}
}
Expand Down