From 3cd2c281d7cf990b3afb78287a58cf4ee3f23ca5 Mon Sep 17 00:00:00 2001 From: Damien George Date: Mon, 3 Sep 2018 17:41:02 +1000 Subject: [PATCH] py/emitnative: Cancel caught exception once handled to prevent reraise. The native emitter keeps the current exception in a slot in its C stack (instead of on its Python value stack), so when it catches an exception it must explicitly clear that slot so the same exception is not reraised later on. --- py/emitnative.c | 4 +++- tests/basics/try_finally1.py | 13 +++++++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/py/emitnative.c b/py/emitnative.c index 5db496a22..a5075eead 100644 --- a/py/emitnative.c +++ b/py/emitnative.c @@ -1892,7 +1892,9 @@ STATIC void emit_native_pop_block(emit_t *emit) { } STATIC void emit_native_pop_except(emit_t *emit) { - (void)emit; + // Cancel any active exception so subsequent handlers don't see it + ASM_MOV_REG_IMM(emit->as, REG_TEMP0, (mp_uint_t)mp_const_none); + ASM_MOV_LOCAL_REG(emit->as, LOCAL_IDX_EXC_VAL(emit), REG_TEMP0); } STATIC void emit_native_unary_op(emit_t *emit, mp_unary_op_t op) { diff --git a/tests/basics/try_finally1.py b/tests/basics/try_finally1.py index 2416f6d18..1e821deb6 100644 --- a/tests/basics/try_finally1.py +++ b/tests/basics/try_finally1.py @@ -69,3 +69,16 @@ try: # top-level catch-all except to not fail script except: print("catch-all except") print() + +# case where a try-except within a finally cancels the exception +print("exc-finally-subexcept") +try: + print("try1") +finally: + try: + print("try2") + foo + except: + print("except2") + print("finally1") +print()