js/src/jit-test/tests/basic/bug972961.js@6474c204b198 (annotated)
js/src/jit-test/tests/basic/bug972961.js
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | // Bug 972961 - Test compiler with very long chains of property accesses |
| michael@0 | 2 | |
| michael@0 | 3 | // Return true if we can compile a chain of n property accesses, |
| michael@0 | 4 | // false if we cannot. Throw if compilation fails in an unexpected way. |
| michael@0 | 5 | function test(n) { |
| michael@0 | 6 | print("testing " + n); |
| michael@0 | 7 | try { |
| michael@0 | 8 | eval('if (false) {' + Array(n).join(("a.")) + 'a}'); |
| michael@0 | 9 | } catch (exc) { |
| michael@0 | 10 | // Expected outcome if the expression is too deeply nested is an InternalError. |
| michael@0 | 11 | if (!(exc instanceof InternalError)) |
| michael@0 | 12 | throw exc; |
| michael@0 | 13 | print(exc.message); |
| michael@0 | 14 | return false; |
| michael@0 | 15 | } |
| michael@0 | 16 | print("no exception"); |
| michael@0 | 17 | return true; |
| michael@0 | 18 | } |
| michael@0 | 19 | |
| michael@0 | 20 | // Find out how long a chain is enough to break the compiler. |
| michael@0 | 21 | var n = 4, LIMIT = 0x000fffff; |
| michael@0 | 22 | var lo = 1, hi = 1; |
| michael@0 | 23 | while (n <= LIMIT && test(n)) { |
| michael@0 | 24 | lo = n; |
| michael@0 | 25 | n *= 4; |
| michael@0 | 26 | } |
| michael@0 | 27 | |
| michael@0 | 28 | // Using binary search, find a pass/fail boundary (in order to |
| michael@0 | 29 | // test the edge case). |
| michael@0 | 30 | if (n <= LIMIT) { |
| michael@0 | 31 | hi = n; |
| michael@0 | 32 | while (lo !== hi) { |
| michael@0 | 33 | var mid = Math.floor((lo + hi) / 2); |
| michael@0 | 34 | if (test(mid)) |
| michael@0 | 35 | lo = mid + 1; |
| michael@0 | 36 | else |
| michael@0 | 37 | hi = mid; |
| michael@0 | 38 | } |
| michael@0 | 39 | print((lo - 1) + " attributes should be enough for anyone"); |
| michael@0 | 40 | } |
