171888 2017-05-09 15:17:04 -0700 Heap::heap() should behave gracefully for null pointers 2017-05-09 15:27:21 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Nightly Build All All RESOLVED FIXED P2 Normal --- 1 fpizlo fpizlo buildbot keith_miller mark.lam msaboff saam oldest_to_newest 1306609 0 fpizlo 2017-05-09 15:17:04 -0700 Some callers of Heap::heap() can pass a null cell and they will behave gracefully if we return a null Heap. So, let's do that. 1306612 1 309549 fpizlo 2017-05-09 15:19:11 -0700 Created attachment 309549 the patch 1306613 2 309549 mark.lam 2017-05-09 15:23:15 -0700 Comment on attachment 309549 the patch View in context: https://bugs.webkit.org/attachment.cgi?id=309549&action=review r=me > Source/JavaScriptCore/heap/HeapInlines.h:49 > + if (!cell) nit: make this "if (UNLIKELY(!cell))" > Source/JavaScriptCore/heap/HeapInlines.h:56 > if (!v.isCell()) might as well make this one UNLIKELY too. 1306614 3 fpizlo 2017-05-09 15:25:56 -0700 (In reply to Mark Lam from comment #2) > Comment on attachment 309549 [details] > the patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=309549&action=review > > r=me > > > Source/JavaScriptCore/heap/HeapInlines.h:49 > > + if (!cell) > > nit: make this "if (UNLIKELY(!cell))" > > > Source/JavaScriptCore/heap/HeapInlines.h:56 > > if (!v.isCell()) > > might as well make this one UNLIKELY too. UNIKELY is unlikely to help if it's for an early return. UNLIKELY is most useful when it lets the compiler know that some code is unlikely to be reached, but here the fall-through path is likely to be reached either way. Also, I already benchmarked it without the UNLIKELY. 1306615 4 fpizlo 2017-05-09 15:27:21 -0700 Landed in https://trac.webkit.org/changeset/216547/webkit 309549 2017-05-09 15:19:11 -0700 2017-05-09 15:23:15 -0700 the patch blah.patch text/plain 1544 fpizlo SW5kZXg6IFNvdXJjZS9KYXZhU2NyaXB0Q29yZS9DaGFuZ2VMb2cKPT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQotLS0gU291 cmNlL0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwkocmV2aXNpb24gMjE2NTQ1KQorKysgU291cmNl L0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwkod29ya2luZyBjb3B5KQpAQCAtMSwzICsxLDIwIEBA CisyMDE3LTA1LTA5ICBGaWxpcCBQaXpsbyAgPGZwaXpsb0BhcHBsZS5jb20+CisKKyAgICAgICAg SGVhcDo6aGVhcCgpIHNob3VsZCBiZWhhdmUgZ3JhY2VmdWxseSBmb3IgbnVsbCBwb2ludGVycwor ICAgICAgICBodHRwczovL2J1Z3Mud2Via2l0Lm9yZy9zaG93X2J1Zy5jZ2k/aWQ9MTcxODg4Cisg ICAgICAgIDxyZGFyOi8vcHJvYmxlbS8zMjAwNTMxNT4KKworICAgICAgICBSZXZpZXdlZCBieSBO T0JPRFkgKE9PUFMhKS4KKyAgICAgICAgCisgICAgICAgIFNvbWUgY2FsbGVycyBvZiBIZWFwOjpo ZWFwKCkgY2FuIHBhc3MgYSBudWxsIGNlbGwgYW5kIHRoZXkgd2lsbCBiZWhhdmUgZ3JhY2VmdWxs eSBpZiB3ZQorICAgICAgICByZXR1cm4gYSBudWxsIEhlYXAuIFNvLCBsZXQncyBkbyB0aGF0Lgor ICAgICAgICAKKyAgICAgICAgVGhpcyBmaXhlcyBhIGNyYXNoIGFuZCBpdCBkb2VzIG5vdCBodXJ0 IHBlcmZvcm1hbmNlLiBJJ20gc2VlaW5nIGEgcG9zc2libGUgMC41JSByZWdyZXNzaW9uCisgICAg ICAgIHdpdGggNzQlIHByb2JhYmlsaXR5LiBUaGF0J3MgYSBuZXV0cmFsIHJlc3VsdCBieSBvdXIg dXN1YWwgOTUlIHN0YW5kYXJkLgorCisgICAgICAgICogaGVhcC9IZWFwSW5saW5lcy5oOgorICAg ICAgICAoSlNDOjpIZWFwOjpoZWFwKToKKwogMjAxNy0wNS0wOSAgWXVzdWtlIFN1enVraSAgPHV0 YXRhbmUudGVhQGdtYWlsLmNvbT4KIAogICAgICAgICBIYW5kbGUgSURMUHJvbWlzZTw+IHByb3Bl cmx5CkluZGV4OiBTb3VyY2UvSmF2YVNjcmlwdENvcmUvaGVhcC9IZWFwSW5saW5lcy5oCj09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT0KLS0tIFNvdXJjZS9KYXZhU2NyaXB0Q29yZS9oZWFwL0hlYXBJbmxpbmVzLmgJKHJldmlz aW9uIDIxNjQ1MikKKysrIFNvdXJjZS9KYXZhU2NyaXB0Q29yZS9oZWFwL0hlYXBJbmxpbmVzLmgJ KHdvcmtpbmcgY29weSkKQEAgLTQ2LDEzICs0NiwxNSBAQCBBTFdBWVNfSU5MSU5FIFZNKiBIZWFw Ojp2bSgpIGNvbnN0CiAKIEFMV0FZU19JTkxJTkUgSGVhcCogSGVhcDo6aGVhcChjb25zdCBIZWFw Q2VsbCogY2VsbCkKIHsKKyAgICBpZiAoIWNlbGwpCisgICAgICAgIHJldHVybiBudWxscHRyOwog ICAgIHJldHVybiBjZWxsLT5oZWFwKCk7CiB9CiAKIGlubGluZSBIZWFwKiBIZWFwOjpoZWFwKGNv bnN0IEpTVmFsdWUgdikKIHsKICAgICBpZiAoIXYuaXNDZWxsKCkpCi0gICAgICAgIHJldHVybiAw OworICAgICAgICByZXR1cm4gbnVsbHB0cjsKICAgICByZXR1cm4gaGVhcCh2LmFzQ2VsbCgpKTsK IH0KIAo=