| // Bug 972961 - Test compiler with very long chains of property accesses |
| |
| // Return true if we can compile a chain of n property accesses, |
| // false if we cannot. Throw if compilation fails in an unexpected way. |
| function test(n) { |
| print("testing " + n); |
| try { |
| eval('if (false) {' + Array(n).join(("a.")) + 'a}'); |
| } catch (exc) { |
| // Expected outcome if the expression is too deeply nested is an InternalError. |
| if (!(exc instanceof InternalError)) |
| throw exc; |
| print(exc.message); |
| return false; |
| } |
| print("no exception"); |
| return true; |
| } |
| |
| // Find out how long a chain is enough to break the compiler. |
| var n = 4, LIMIT = 0x000fffff; |
| var lo = 1, hi = 1; |
| while (n <= LIMIT && test(n)) { |
| lo = n; |
| n *= 4; |
| } |
| |
| // Using binary search, find a pass/fail boundary (in order to |
| // test the edge case). |
| if (n <= LIMIT) { |
| hi = n; |
| while (lo !== hi) { |
| var mid = Math.floor((lo + hi) / 2); |
| if (test(mid)) |
| lo = mid + 1; |
| else |
| hi = mid; |
| } |
| print((lo - 1) + " attributes should be enough for anyone"); |
| } |