Bug 167282

Summary:

JavaScriptCore has a weak external symbol in it

Product:

WebKit

Reporter:

Shuan Zhao <hszhsh>

Component:

JavaScriptCore

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

ap, commit-queue, joepeck, keith_miller, mark.lam, msaboff, saam

Priority:

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
[PATCH] Proposed Fix	none

Description Shuan Zhao 2017-01-21 02:05:41 PST

ERROR: JavaScriptCore has a weak external symbol in it (/Users/hoolai/Library/Developer/Xcode/DerivedData/WebKit-ehpvmnqmihxdvndqudiokzoxdfuu/Build/Products/Debug/JavaScriptCore.framework/Versions/A/JavaScriptCore)
ERROR: A weak external symbol is generated when a symbol is defined in multiple compilation units and is also marked as being exported from the library.
ERROR: A common cause of weak external symbols is when an inline function is listed in the linker export file.
ERROR: symbol automatically hidden __ZTVN3JSC8Debugger15ProfilingClientE

Comment 1 Alexey Proskuryakov 2017-01-21 23:29:17 PST

I don't think that we've seen this particular error. What version of Xcode are you building with?

Comment 2 Shuan Zhao 2017-01-21 23:32:26 PST

I'm using Xcode Version 8.2.1 (8C1002)

Comment 3 Alexey Proskuryakov 2017-01-21 23:52:10 PST

Our bots have version 8.2, which is unlikely to be different in this regard. What command do you build with?

Comment 4 Shuan Zhao 2017-01-22 00:14:51 PST

I just open the workspace file with Xcode, and select the JavaScriptCore target. I have changed the Mach-O Type to static library to run on iOS with my own app. Error was reported for debug build. I can make the release build successfully.

Comment 5 Joseph Pecoraro 2017-01-22 18:41:47 PST

This seems like an issue that I used to see in the past that was solved by newer compilers. In any case, it sounds like we can just make the destructor:

    virtual ~ProfilingClient() { }

Not be inlined to solve this. I'll try to reproduce myself tonight, but I'll just throw up a patch anyways.

Comment 6 Joseph Pecoraro 2017-01-22 22:14:00 PST

With:

  $ xcrun clang++ -v
  Apple LLVM version 8.1.0 (clang-802.0.21.2)

I only see these weak externals:

  $ nm -m $build/Release/JavaScriptCore.framework/JavaScriptCore | grep 'weak external'
    (undefined) weak external __ZdaPv (from libc++)
    (undefined) weak external __ZdlPv (from libc++)
    (undefined) weak external __Znam (from libc++)
    (undefined) weak external __Znwm (from libc++)

So I guess I can go ahead speculatively here, seems harmless.

Comment 7 Joseph Pecoraro 2017-01-22 22:16:29 PST

Created attachment 299500 [details]
[PATCH] Proposed Fix

Comment 8 Joseph Pecoraro 2017-01-22 22:17:03 PST

Shuan, since I can't reproduce but you can, would you be willing to try the attached patch (very basic) and see if it solves the problem for you?

Comment 9 Shuan Zhao 2017-01-22 22:20:19 PST

Ok, I'll try it and report my result later.

Comment 10 Shuan Zhao 2017-01-22 23:35:47 PST

The patch solved my problem. Thanks for you work.

Comment 11 Yusuke Suzuki 2017-01-23 02:18:28 PST

Comment on attachment 299500 [details]
[PATCH] Proposed Fix

ok, r=me

Comment 12 WebKit Commit Bot 2017-01-23 02:42:58 PST

Comment on attachment 299500 [details]
[PATCH] Proposed Fix

Clearing flags on attachment: 299500

Committed r211037: <http://trac.webkit.org/changeset/211037>

Comment 13 WebKit Commit Bot 2017-01-23 02:43:02 PST

All reviewed patches have been landed.  Closing bug.