1572385 - js/src/vm/StringType.h:338:5: error: static_assert failed due to requirement 'JSString::offsetOfFlags() == __builtin_offsetof(JS::shadow::String, flags_)' "shadow::String flags offset must match JSString" on s390x, and presumably other big-endians

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P2)

Description

[Mike Hommey [:glandium]]

https://treeherder.mozilla.org/logviewer.html#?job_id=260536670&repo=try

[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/gc/StoreBuffer.cpp:7:
[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/gc/StoreBuffer-inl.h:15:
[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/gc/Heap-inl.h:13:
[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/gc/Zone.h:15:
[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/gc/ZoneAllocator.h:15:
[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/vm/Runtime.h:24:
[task 2019-08-08T06:27:15.779Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/builtin/AtomicsObject.h:15:
[task 2019-08-08T06:27:15.780Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/vm/JSObject.h:18:
[task 2019-08-08T06:27:15.780Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/vm/Shape.h:32:
[task 2019-08-08T06:27:15.780Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/vm/ObjectGroup.h:19:
[task 2019-08-08T06:27:15.780Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/vm/TypeSet.h:22:
[task 2019-08-08T06:27:15.780Z] 06:27:15     INFO -  In file included from /builds/worker/workspace/build/src/js/src/jit/IonTypes.h:19:
[task 2019-08-08T06:27:15.780Z] 06:27:15    ERROR -  /builds/worker/workspace/build/src/js/src/vm/StringType.h:338:5: error: static_assert failed due to requirement 'JSString::offsetOfFlags() == __builtin_offsetof(JS::shadow::String, flags_)' "shadow::String flags offset must match JSString"
[task 2019-08-08T06:27:15.781Z] 06:27:15     INFO -      static_assert(JSString::offsetOfFlags() == offsetof(String, flags_),
[task 2019-08-08T06:27:15.781Z] 06:27:15     INFO -      ^             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[task 2019-08-08T06:27:15.781Z] 06:27:15     INFO -  1 error generated.
[task 2019-08-08T06:27:15.781Z] 06:27:15     INFO -  /builds/worker/workspace/build/src/config/rules.mk:786: recipe for target 'StoreBuffer.o' failed

Comment 1

[Jan de Mooij [:jandem]]

This static assert used to check:

offsetof(JSString, d.flags_) == offsetof(String, flags_)

But now it checks:

JSString::offsetOfFlags() == offsetof(String, flags_)

We could go back to checking the raw flags_ field offset I suppose.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug is a defect, but please change it back in case of error.

Comment 3

[Ted Campbell [:tcampbell]]

Yeah, checking the raw field makes sense. The 'offsetOfFlags' stuff is really just for jits.

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Bug 1572385 - Check raw flags_ field offset in JSString::staticAsserts to fix 64-bit big-endian platforms. r?tcampbell!

The length_ and flags_ fields are private so I added a protected offsetOf* accessor.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0d98b57bcabf
Check raw flags_ field offset in JSString::staticAsserts to fix 64-bit big-endian platforms. r=tcampbell

Comment 6

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/0d98b57bcabf