1
2
3
4
5
6 :(scenario jump_to_different_function)
7 % Hide_errors = true;
8 == 0x1
9 fn1:
10 7e/jump-if $target/disp8
11 fn2:
12 $target:
13 +error: '7e/jump-if $target/disp8' in function 'fn1': jump to within another function 'fn2' is a *really* bad idea
14
15 :(before "Rewrite Labels(segment code)")
16 check_local_jumps(code);
17 if (trace_contains_errors()) return;
18 :(code)
19 void check_local_jumps(const segment& code) {
20 map<string, string> function;
21 compute_function_target(code, function);
22 if (trace_contains_errors()) return;
23 string current_function;
24 for (int i = 0; i < SIZE(code.lines); ++i) {
25 const line& inst = code.lines.at(i);
26 if (SIZE(inst.words) == 1 && is_label(inst.words.at(0))) {
27
28 if (inst.words.at(0).data.at(0) != '$')
29 current_function = drop_last(inst.words.at(0).data);
30 }
31 else if (is_jump(inst)) {
32 const word& target = inst.words.at(first_operand(inst));
33 if (!contains_key(function, target.data)) continue;
34 if (get(function, target.data) == current_function) continue;
35 raise << "'" << to_string(inst) << "' in function '" << current_function << "': jump to within another function '" << get(function, target.data) << "' is a *really* bad idea\n" << end();
36 return;
37 }
38 }
39 }
40
41 void compute_function_target(const segment& code, map<string, string>& out) {
42 string current_function;
43 for (int i = 0; i < SIZE(code.lines); ++i) {
44 const line& inst = code.lines.at(i);
45 if (SIZE(inst.words) != 1) continue;
46 const word& curr = inst.words.at(0);
47 if (!is_label(curr)) continue;
48 const string& label = drop_last(curr.data);
49 if (label.at(0) != '$') {
50 current_function = label;
51 continue;
52 }
53 if (contains_key(out, label)) {
54 raise << "duplicate label '" << label << "'\n" << end();
55 return;
56 }
57
58 put(out, label, current_function);
59 }
60 }