gh-156466: fix cleanup on error after Enter in codegen_enter_scope - #156467
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iritkatriel wants to merge 1 commit into
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gh-156466: fix cleanup on error after Enter in codegen_enter_scope#156467iritkatriel wants to merge 1 commit into
iritkatriel wants to merge 1 commit into
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iritkatriel
added
3.14
picnixz
added
needs backport to 3.14
carljm
approved these changes
Aug 28, 2026
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| ADDOP_I(c, loc, RESUME, RESUME_AT_FUNC_START); | ||
| ADDOP_I_IN_SCOPE(c, loc, RESUME, RESUME_AT_FUNC_START); |
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I think we should also guard the final _PyCompile_ExitScope(c) in _PyCompile_CodeGen() with if (c->u != NULL), as compiler_mod() does?
If allocating the module's initial RESUME fails, this now exits the only scope and leaves c->u as NULL. _PyCompile_CodeGen() then reaches its unconditional final exit (Python/compile.c:1738), which dereferences c->u and segfaults.
I reproduced this with an allocator hook that fails the initial instruction-buffer allocation during:
import ast
import _testinternalcapi
_testinternalcapi.compiler_codegen(ast.parse("pass"), "<test>", 0)Main propagates MemoryError, whereas this PR crashes. Normal compile() already handles the cleanup correctly.
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If
codegen_enter_scopeerrors after_PyCompile_EnterScope, it should exit the scope before returningERROR.