https://github.com/python/cpython/commit/21866c8ed296524f0ca175c0f55b43744c2b30df
commit: 21866c8ed296524f0ca175c0f55b43744c2b30df
branch: main
author: Irit Katriel <[email protected]>
committer: iritkatriel <[email protected]>
date: 2024-06-17T10:10:06Z
summary:
gh-120367: fix removal of redundant NOPs and jumps after reordering hot-cold
blocks (#120425)
files:
A Misc/NEWS.d/next/Core and
Builtins/2024-06-12-18-50-29.gh-issue-120367.LmXx2y.rst
M Lib/test/test_compile.py
M Python/flowgraph.c
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index ae23aea08d99bc..219314b5ce3d6f 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -502,6 +502,33 @@ def test_compile_invalid_namedexpr(self):
with self.assertRaisesRegex(TypeError, "NamedExpr target must be a
Name"):
compile(ast.fix_missing_locations(m), "<file>", "exec")
+ def test_compile_redundant_jumps_and_nops_after_moving_cold_blocks(self):
+ # See gh-120367
+ code=textwrap.dedent("""
+ try:
+ pass
+ except:
+ pass
+ else:
+ match name_2:
+ case b'':
+ pass
+ finally:
+ something
+ """)
+
+ tree = ast.parse(code)
+
+ # make all instructions locations the same to create redundancies
+ for node in ast.walk(tree):
+ if hasattr(node,"lineno"):
+ del node.lineno
+ del node.end_lineno
+ del node.col_offset
+ del node.end_col_offset
+
+ compile(ast.fix_missing_locations(tree), "<file>", "exec")
+
def test_compile_ast(self):
fname = __file__
if fname.lower().endswith('pyc'):
diff --git a/Misc/NEWS.d/next/Core and
Builtins/2024-06-12-18-50-29.gh-issue-120367.LmXx2y.rst b/Misc/NEWS.d/next/Core
and Builtins/2024-06-12-18-50-29.gh-issue-120367.LmXx2y.rst
new file mode 100644
index 00000000000000..2d7212a66f7a84
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and
Builtins/2024-06-12-18-50-29.gh-issue-120367.LmXx2y.rst
@@ -0,0 +1,2 @@
+Fix crash in compiler on code with redundant NOPs and JUMPs which show up
+after exception handlers are moved to the end of the code.
diff --git a/Python/flowgraph.c b/Python/flowgraph.c
index aed694aee91f91..6f30dfcd33e0b4 100644
--- a/Python/flowgraph.c
+++ b/Python/flowgraph.c
@@ -1857,6 +1857,22 @@ optimize_basic_block(PyObject *const_cache, basicblock
*bb, PyObject *consts)
static int resolve_line_numbers(cfg_builder *g, int firstlineno);
+static int
+remove_redundant_nops_and_jumps(cfg_builder *g)
+{
+ int removed_nops, removed_jumps;
+ do {
+ /* Convergence is guaranteed because the number of
+ * redundant jumps and nops only decreases.
+ */
+ removed_nops = remove_redundant_nops(g);
+ RETURN_IF_ERROR(removed_nops);
+ removed_jumps = remove_redundant_jumps(g);
+ RETURN_IF_ERROR(removed_jumps);
+ } while(removed_nops + removed_jumps > 0);
+ return SUCCESS;
+}
+
/* Perform optimizations on a control flow graph.
The consts object should still be in list form to allow new constants
to be appended.
@@ -1878,17 +1894,7 @@ optimize_cfg(cfg_builder *g, PyObject *consts, PyObject
*const_cache, int firstl
}
RETURN_IF_ERROR(remove_redundant_nops_and_pairs(g->g_entryblock));
RETURN_IF_ERROR(remove_unreachable(g->g_entryblock));
-
- int removed_nops, removed_jumps;
- do {
- /* Convergence is guaranteed because the number of
- * redundant jumps and nops only decreases.
- */
- removed_nops = remove_redundant_nops(g);
- RETURN_IF_ERROR(removed_nops);
- removed_jumps = remove_redundant_jumps(g);
- RETURN_IF_ERROR(removed_jumps);
- } while(removed_nops + removed_jumps > 0);
+ RETURN_IF_ERROR(remove_redundant_nops_and_jumps(g));
assert(no_redundant_jumps(g));
return SUCCESS;
}
@@ -2358,7 +2364,7 @@ push_cold_blocks_to_end(cfg_builder *g) {
b->b_next = cold_blocks;
if (cold_blocks != NULL) {
- RETURN_IF_ERROR(remove_redundant_jumps(g));
+ RETURN_IF_ERROR(remove_redundant_nops_and_jumps(g));
}
return SUCCESS;
}
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