https://github.com/python/cpython/commit/c1bf4874c1e9db2beda1d62c8c241229783c789b
commit: c1bf4874c1e9db2beda1d62c8c241229783c789b
branch: main
author: Irit Katriel <[email protected]>
committer: encukou <[email protected]>
date: 2024-05-01T13:01:16+02:00
summary:
gh-116767: fix crash on 'async with' with many context managers (GH-118348)
Account for `add_stopiteration_handler` pushing a block for `async with`.
To allow generator functions that previously almost hit the `CO_MAXBLOCKS`
limit by nesting non-async blocks, the limit is increased by 1.
This increase allows one more block in non-generator functions.
files:
A Misc/NEWS.d/next/Core and
Builtins/2024-04-27-16-23-29.gh-issue-116767.z9UFpr.rst
M Include/cpython/code.h
M Lib/test/test_syntax.py
M Python/compile.c
diff --git a/Include/cpython/code.h b/Include/cpython/code.h
index b0e226e0e1971a..ef8f9304ccab56 100644
--- a/Include/cpython/code.h
+++ b/Include/cpython/code.h
@@ -226,7 +226,7 @@ struct PyCodeObject _PyCode_DEF(1);
*/
#define PY_PARSER_REQUIRES_FUTURE_KEYWORD
-#define CO_MAXBLOCKS 20 /* Max static block nesting within a function */
+#define CO_MAXBLOCKS 21 /* Max static block nesting within a function */
PyAPI_DATA(PyTypeObject) PyCode_Type;
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index e9bec3317811dd..de783f714509a3 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -2392,13 +2392,40 @@ def bug():
code += "): yield a"
return code
- CO_MAXBLOCKS = 20 # static nesting limit of the compiler
+ CO_MAXBLOCKS = 21 # static nesting limit of the compiler
+ MAX_MANAGERS = CO_MAXBLOCKS - 1 # One for the StopIteration block
- for n in range(CO_MAXBLOCKS):
+ for n in range(MAX_MANAGERS):
with self.subTest(f"within range: {n=}"):
compile(get_code(n), "<string>", "exec")
- for n in range(CO_MAXBLOCKS, CO_MAXBLOCKS + 5):
+ for n in range(MAX_MANAGERS, MAX_MANAGERS + 5):
+ with self.subTest(f"out of range: {n=}"):
+ self._check_error(get_code(n), "too many statically nested
blocks")
+
+ @support.cpython_only
+ def test_async_with_statement_many_context_managers(self):
+ # See gh-116767
+
+ def get_code(n):
+ code = [ textwrap.dedent("""
+ async def bug():
+ async with (
+ a
+ """) ]
+ for i in range(n):
+ code.append(f" as a{i}, a\n")
+ code.append("): yield a")
+ return "".join(code)
+
+ CO_MAXBLOCKS = 21 # static nesting limit of the compiler
+ MAX_MANAGERS = CO_MAXBLOCKS - 1 # One for the StopIteration block
+
+ for n in range(MAX_MANAGERS):
+ with self.subTest(f"within range: {n=}"):
+ compile(get_code(n), "<string>", "exec")
+
+ for n in range(MAX_MANAGERS, MAX_MANAGERS + 5):
with self.subTest(f"out of range: {n=}"):
self._check_error(get_code(n), "too many statically nested
blocks")
@@ -2536,7 +2563,8 @@ def test_syntax_error_on_deeply_nested_blocks(self):
while 20:
while 21:
while 22:
- break
+ while 23:
+ break
"""
self._check_error(source, "too many statically nested blocks")
diff --git a/Misc/NEWS.d/next/Core and
Builtins/2024-04-27-16-23-29.gh-issue-116767.z9UFpr.rst b/Misc/NEWS.d/next/Core
and Builtins/2024-04-27-16-23-29.gh-issue-116767.z9UFpr.rst
new file mode 100644
index 00000000000000..cec2041d12ee15
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and
Builtins/2024-04-27-16-23-29.gh-issue-116767.z9UFpr.rst
@@ -0,0 +1 @@
+Fix crash in compiler on 'async with' that has many context managers.
diff --git a/Python/compile.c b/Python/compile.c
index ca5551a8e64ab0..4e94f9297a32d1 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -113,7 +113,8 @@ compiler IR.
enum fblocktype { WHILE_LOOP, FOR_LOOP, TRY_EXCEPT, FINALLY_TRY, FINALLY_END,
WITH, ASYNC_WITH, HANDLER_CLEANUP, POP_VALUE,
EXCEPTION_HANDLER,
- EXCEPTION_GROUP_HANDLER, ASYNC_COMPREHENSION_GENERATOR };
+ EXCEPTION_GROUP_HANDLER, ASYNC_COMPREHENSION_GENERATOR,
+ STOP_ITERATION };
struct fblockinfo {
enum fblocktype fb_type;
@@ -1503,6 +1504,7 @@ compiler_unwind_fblock(struct compiler *c, location *ploc,
case EXCEPTION_HANDLER:
case EXCEPTION_GROUP_HANDLER:
case ASYNC_COMPREHENSION_GENERATOR:
+ case STOP_ITERATION:
return SUCCESS;
case FOR_LOOP:
@@ -2232,14 +2234,26 @@ compiler_function_body(struct compiler *c, stmt_ty s,
int is_async, Py_ssize_t f
c->u->u_metadata.u_argcount = asdl_seq_LEN(args->args);
c->u->u_metadata.u_posonlyargcount = asdl_seq_LEN(args->posonlyargs);
c->u->u_metadata.u_kwonlyargcount = asdl_seq_LEN(args->kwonlyargs);
+
+ NEW_JUMP_TARGET_LABEL(c, start);
+ USE_LABEL(c, start);
+ bool add_stopiteration_handler = c->u->u_ste->ste_coroutine ||
c->u->u_ste->ste_generator;
+ if (add_stopiteration_handler) {
+ /* wrap_in_stopiteration_handler will push a block, so we need to
account for that */
+ RETURN_IF_ERROR(
+ compiler_push_fblock(c, NO_LOCATION, STOP_ITERATION,
+ start, NO_LABEL, NULL));
+ }
+
for (Py_ssize_t i = first_instr; i < asdl_seq_LEN(body); i++) {
VISIT_IN_SCOPE(c, stmt, (stmt_ty)asdl_seq_GET(body, i));
}
- if (c->u->u_ste->ste_coroutine || c->u->u_ste->ste_generator) {
+ if (add_stopiteration_handler) {
if (wrap_in_stopiteration_handler(c) < 0) {
compiler_exit_scope(c);
return ERROR;
}
+ compiler_pop_fblock(c, STOP_ITERATION, start);
}
PyCodeObject *co = optimize_and_assemble(c, 1);
compiler_exit_scope(c);
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