commit 11420791428f82010a3b77ee960c1b4d6958952f
author zforman <zforman@google.com> Sun Dec 13 19:23:36 2015 -0800
committer Commit bot <commit-bot@chromium.org> Mon Dec 14 03:24:33 2015 +0000
tree 5e7f19c6c4ffefa33260e59874e2a96c1d6d158b
parent 81d48c2efb4b11dc3ace3ce262f2840120db7c37

GN: Makes GN output deterministic

Sorts various output just prior to printing to ensure that GN output
is deterministic.

The overall effect on performance is relatively small, with
runtime over 50 runs varying as follows on my Z840:

    +-------+-------+-------+
    |       |  old  |  new  |
    +-------+-------+-------+
    | mean  | 1415  | 1430  |
    +-------+-------+-------+
    | stdev | 58.0  | 70.5  |
    +-------+-------+-------+

To verify results:
$ gn gen out/Default; mv out out-1
$ gn gen out/Default; mv out out-2
$ diff -qr out-1 out-2

The diff should be empty.

Initial discussion can be seen at https://groups.google.com/a/chromium.org/forum/#!topic/gn-dev/8mOLgM4r3PI.

BUG=565075

Review URL: https://codereview.chromium.org/1494883002

Cr-Original-Commit-Position: refs/heads/master@{#364954}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 98ec25a8fb3f710d43d60b1bcdc5a1475aab136f