Remove PyTryblock struct (GH-26059)

Author: markshannon

Include/cpython/frameobject.h

@@ -19,12 +19,6 @@ enum _framestate {
 
 typedef signed char PyFrameState;
 
-typedef struct {
- int b_type; /* what kind of block this is */
- int b_handler; /* where to jump to find handler */
- int b_level; /* value stack level to pop to */
-} PyTryBlock;
-
 struct _frame {
  PyObject_VAR_HEAD
  struct _frame *f_back; /* previous frame, or NULL */

Python/ceval.c

@@ -95,7 +95,7 @@ static PyObject * special_lookup(PyThreadState *, PyObject *, _Py_Identifier *);
 static int check_args_iterable(PyThreadState *, PyObject *func, PyObject *vararg);
 static void format_kwargs_error(PyThreadState *, PyObject *func, PyObject *kwargs);
 static void format_awaitable_error(PyThreadState *, PyTypeObject *, int, int);
-static PyTryBlock get_exception_handler(PyCodeObject *, int);
+static int get_exception_handler(PyCodeObject *, int, int*, int*, int*);
 
 #define NAME_ERROR_MSG \
  "name '%.200s' is not defined"
@@ -4461,21 +4461,20 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
 exception_unwind:
  f->f_state = FRAME_UNWINDING;
  /* We can't use f->f_lasti here, as RERAISE may have set it */
- int lasti = INSTR_OFFSET()-1;
- PyTryBlock from_table = get_exception_handler(co, lasti);
- if (from_table.b_handler < 0) {
+ int offset = INSTR_OFFSET()-1;
+ int level, handler, lasti;
+ if (get_exception_handler(co, offset, &level, &handler, &lasti) == 0) {
  // No handlers, so exit.
  break;
  }
 
- assert(STACK_LEVEL() >= from_table.b_level);
- while (STACK_LEVEL() > from_table.b_level) {
+ assert(STACK_LEVEL() >= level);
+ while (STACK_LEVEL() > level) {
  PyObject *v = POP();
  Py_XDECREF(v);
  }
  PyObject *exc, *val, *tb;
- int handler = from_table.b_handler;
- if (from_table.b_type) {
+ if (lasti) {
  PyObject *lasti = PyLong_FromLong(f->f_lasti);
  if (lasti == NULL) {
  goto exception_unwind;
@@ -4811,21 +4810,11 @@ parse_range(unsigned char *p, int *start, int*end)
  return p;
 }
 
-static inline void
-parse_block(unsigned char *p, PyTryBlock *block) {
- int depth_and_lasti;
- p = parse_varint(p, &block->b_handler);
- p = parse_varint(p, &depth_and_lasti);
- block->b_level = depth_and_lasti >> 1;
- block->b_type = depth_and_lasti & 1;
-}
-
 #define MAX_LINEAR_SEARCH 40
 
-static PyTryBlock
-get_exception_handler(PyCodeObject *code, int index)
+static int
+get_exception_handler(PyCodeObject *code, int index, int *level, int *handler, int *lasti)
 {
- PyTryBlock res;
  unsigned char *start = (unsigned char *)PyBytes_AS_STRING(code->co_exceptiontable);
  unsigned char *end = start + PyBytes_GET_SIZE(code->co_exceptiontable);
  /* Invariants:
@@ -4837,8 +4826,7 @@ get_exception_handler(PyCodeObject *code, int index)
  int offset;
  parse_varint(start, &offset);
  if (offset > index) {
- res.b_handler = -1;
- return res;
+ return 0;
  }
  do {
  unsigned char * mid = start + ((end-start)>>1);
@@ -4862,13 +4850,16 @@ get_exception_handler(PyCodeObject *code, int index)
  }
  scan = parse_varint(scan, &size);
  if (start_offset + size > index) {
- parse_block(scan, &res);
- return res;
+ scan = parse_varint(scan, handler);
+ int depth_and_lasti;
+ parse_varint(scan, &depth_and_lasti);
+ *level = depth_and_lasti >> 1;
+ *lasti = depth_and_lasti & 1;
+ return 1;
  }
  scan = skip_to_next_entry(scan, end);
  }
- res.b_handler = -1;
- return res;
+ return 0;
 }
 
 PyFrameObject *