Fix try/catch (fix jqlang#1859)

src/execute.c

@@ -253,6 +253,7 @@ struct forkpoint {
  int path_len, subexp_nest;
  jv value_at_path;
  uint16_t* return_address;
+ uint16_t* call_address; /* for tr/catch */
 };
 
 struct stack_pos {
@@ -274,6 +275,7 @@ void stack_save(jq_state *jq, uint16_t* retaddr, struct stack_pos sp){
  fork->value_at_path = jv_copy(jq->value_at_path);
  fork->subexp_nest = jq->subexp_nest;
  fork->return_address = retaddr;
+ fork->call_address = 0;
  jq->stk_top = sp.saved_data_stack;
  jq->curr_frame = sp.saved_curr_frame;
 }
@@ -339,6 +341,7 @@ uint16_t* stack_restore(jq_state *jq){
  }
 
  struct forkpoint* fork = stack_block(&jq->stk, jq->fork_top);
+ uint16_t* call_address = fork->call_address;
  uint16_t* retaddr = fork->return_address;
  jq->stk_top = fork->saved_data_stack;
  jq->curr_frame = fork->saved_curr_frame;
@@ -353,6 +356,11 @@ uint16_t* stack_restore(jq_state *jq){
  jq->value_at_path = fork->value_at_path;
  jq->subexp_nest = fork->subexp_nest;
  jq->fork_top = stack_pop_block(&jq->stk, jq->fork_top, sizeof(struct forkpoint));
+ if (jq->fork_top) {
+ fork = stack_block(&jq->stk, jq->fork_top);
+ if (!fork->call_address || fork->call_address < call_address)
+ fork->call_address = call_address;
+ }
  return retaddr;
 }
 
@@ -438,6 +446,7 @@ jv jq_next(jq_state *jq) {
  }
  assert(pc);
 
+ uint16_t *error_source = 0;
  int raising;
  int backtracking = !jq->initial_execution;
  jq->initial_execution = 0;
@@ -896,6 +905,12 @@ jv jq_next(jq_state *jq) {
  jq->finished = 1;
  return jv_invalid();
  }
+ if (!jv_is_valid(jq->error) && jq->fork_top && jq->curr_frame > jq->fork_top) {
+ struct forkpoint* frk = stack_block(&jq->stk, jq->fork_top);
+ error_source = frk->call_address;
+ } else {
+ error_source = pc;
+ }
  backtracking = 1;
  break;
  }
@@ -915,17 +930,22 @@ jv jq_next(jq_state *jq) {
  jv_free(stack_pop(jq));
  goto do_backtrack;
  }
+
+ uint16_t offset = *pc++;
+
  // `try EXP ...` exception caught in EXP
  // DESTRUCTURE_ALT doesn't want the error message on the stack,
  // as we would just want to throw it away anyway.
  if (opcode != ON_BACKTRACK(DESTRUCTURE_ALT)) {
  jv_free(stack_pop(jq)); // free the input
+ if (error_source > (pc + offset))
+ goto do_backtrack;
  stack_push(jq, jv_invalid_get_msg(jq->error)); // push the error's message
  } else {
+ error_source = 0;
  jv_free(jq->error);
  }
  jq->error = jv_null();
- uint16_t offset = *pc++;
  pc += offset;
  break;
  }
@@ -937,6 +957,10 @@ jv jq_next(jq_state *jq) {
  }
 
  case CALL_BUILTIN: {
+ if (jq->fork_top && jq->curr_frame > jq->fork_top) {
+ struct forkpoint* frk = stack_block(&jq->stk, jq->fork_top);
+ frk->call_address = pc;
+ }
  int nargs = *pc++;
  jv top = stack_pop(jq);
  jv* in = cfunc_input;
@@ -976,6 +1000,10 @@ jv jq_next(jq_state *jq) {
 
  case TAIL_CALL_JQ:
  case CALL_JQ: {
+ if (jq->fork_top && jq->curr_frame > jq->fork_top) {
+ struct forkpoint* frk = stack_block(&jq->stk, jq->fork_top);
+ frk->call_address = pc;
+ }
  /*
  * Bytecode layout here:
  *
@@ -1246,6 +1274,8 @@ jv jq_next(jq_state *jq) {
  case ON_BACKTRACK(CORET):
  case ON_BACKTRACK(RET): {
  // resumed after top-level return
+ if (!jv_is_valid(jq->error))
+ error_source = pc;
  goto do_backtrack;
  }
  }