diff options
Diffstat (limited to 'py/vm.c')
| -rw-r--r-- | py/vm.c | 43 |
1 files changed, 23 insertions, 20 deletions
@@ -17,16 +17,6 @@ // top element. // Exception stack also grows up, top element is also pointed at. -// Exception stack entry -typedef struct _mp_exc_stack { - const byte *handler; - // bit 0 is saved currently_in_except_block value - machine_uint_t val_sp; - // We might only have 2 interesting cases here: SETUP_EXCEPT & SETUP_FINALLY, - // consider storing it in bit 1 of val_sp. TODO: SETUP_WITH? - byte opcode; -} mp_exc_stack; - // Exception stack unwind reasons (WHY_* in CPython-speak) // TODO perhaps compress this to RETURN=0, JUMP>0, with number of unwinds // left to do encoded in the JUMP number @@ -89,8 +79,10 @@ mp_vm_return_kind_t mp_execute_byte_code(const byte *code, const mp_obj_t *args, } } + mp_exc_stack exc_stack[4]; + mp_exc_stack *exc_sp = &exc_stack[0] - 1; // execute the byte code - mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(code, &ip, &state[n_state - 1], &sp); + mp_vm_return_kind_t vm_return_kind = mp_execute_byte_code_2(code, &ip, &state[n_state - 1], &sp, exc_stack, &exc_sp, MP_OBJ_NULL); switch (vm_return_kind) { case MP_VM_RETURN_NORMAL: @@ -113,7 +105,10 @@ mp_vm_return_kind_t mp_execute_byte_code(const byte *code, const mp_obj_t *args, // MP_VM_RETURN_NORMAL, sp valid, return value in *sp // MP_VM_RETURN_YIELD, ip, sp valid, yielded value in *sp // MP_VM_RETURN_EXCEPTION, exception in fastn[0] -mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **ip_in_out, mp_obj_t *fastn, mp_obj_t **sp_in_out) { +mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **ip_in_out, + mp_obj_t *fastn, mp_obj_t **sp_in_out, + mp_exc_stack *exc_stack, mp_exc_stack **exc_sp_in_out, + volatile mp_obj_t inject_exc) { // careful: be sure to declare volatile any variables read in the exception handler (written is ok, I think) const byte *ip = *ip_in_out; @@ -123,14 +118,21 @@ mp_vm_return_kind_t mp_execute_byte_code_2(const byte *code_info, const byte **i mp_obj_t obj1, obj2; nlr_buf_t nlr; - volatile machine_uint_t currently_in_except_block = 0; // 0 or 1, to detect nested exceptions - mp_exc_stack exc_stack[4]; - mp_exc_stack *volatile exc_sp = &exc_stack[0] - 1; // stack grows up, exc_sp points to top of stack + volatile machine_uint_t currently_in_except_block = (int)*exc_sp_in_out & 1; // 0 or 1, to detect nested exceptions + mp_exc_stack *volatile exc_sp = (void*)((int)*exc_sp_in_out & ~1); // stack grows up, exc_sp points to top of stack const byte *volatile save_ip = ip; // this is so we can access ip in the exception handler without making ip volatile (which means the compiler can't keep it in a register in the main loop) // outer exception handling loop for (;;) { if (nlr_push(&nlr) == 0) { + // If we have exception to inject, now that we finish setting up + // execution context, raise it. This works as if RAISE_VARARGS + // bytecode was executed. + if (inject_exc != MP_OBJ_NULL) { + mp_obj_t t = inject_exc; + inject_exc = MP_OBJ_NULL; + nlr_jump(rt_make_raise_obj(t)); + } // loop to execute byte code for (;;) { dispatch_loop: @@ -434,7 +436,7 @@ unwind_jump: // matched against: SETUP_EXCEPT, SETUP_FINALLY, SETUP_WITH case MP_BC_POP_BLOCK: // we are exiting an exception handler, so pop the last one of the exception-stack - assert(exc_sp >= &exc_stack[0]); + assert(exc_sp >= exc_stack); currently_in_except_block = (exc_sp->val_sp & 1); // restore previous state exc_sp--; // pop back to previous exception handler break; @@ -443,7 +445,7 @@ unwind_jump: case MP_BC_POP_EXCEPT: // TODO need to work out how blocks work etc // pops block, checks it's an exception block, and restores the stack, saving the 3 exception values to local threadstate - assert(exc_sp >= &exc_stack[0]); + assert(exc_sp >= exc_stack); assert(currently_in_except_block); //sp = (mp_obj_t*)(*exc_sp--); //exc_sp--; // discard ip @@ -592,7 +594,7 @@ unwind_return: } nlr_pop(); *sp_in_out = sp; - assert(exc_sp == &exc_stack[0] - 1); + assert(exc_sp == exc_stack - 1); return MP_VM_RETURN_NORMAL; case MP_BC_RAISE_VARARGS: @@ -605,6 +607,7 @@ unwind_return: nlr_pop(); *ip_in_out = ip; *sp_in_out = sp; + *exc_sp_in_out = (void*)((int)exc_sp | currently_in_except_block); return MP_VM_RETURN_YIELD; case MP_BC_IMPORT_NAME: @@ -654,7 +657,7 @@ unwind_return: while (currently_in_except_block) { // nested exception - assert(exc_sp >= &exc_stack[0]); + assert(exc_sp >= exc_stack); // TODO make a proper message for nested exception // at the moment we are just raising the very last exception (the one that caused the nested exception) @@ -664,7 +667,7 @@ unwind_return: exc_sp--; // pop back to previous exception handler } - if (exc_sp >= &exc_stack[0]) { + if (exc_sp >= exc_stack) { // set flag to indicate that we are now handling an exception currently_in_except_block = 1; |