592052 - Missing NSGetModule export (binary backwards compatiblity)

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[Nils Maier [:nmaier]]

Attachment: patch v1, add missing export back

1.9.2 binary compatiblity stuff was added by bug 568691:
http://hg.mozilla.org/mozilla-central/rev/21ebf7198406

However, the global exports (gnu-ld) were removed in bug 568691, and are hence missing:
http://hg.mozilla.org/mozilla-central/rev/014f02585f6d

The NSGetModule export must be added again in order to get working backwards-compatible binaries.

Comment 1

[Nils Maier [:nmaier]]

Nominating blocking. Should be no risk, and omitting it will prevent third-party authors from building mixed 1.9.2/2.0 binary components.

Comment 2

[Benjamin Smedberg]

If NSGetModule *isn't* present (which is the common case), does this cause build warnings or errors?

Comment 3

[Benjamin Smedberg]

This definitely doesn't block, and can be worked around by component authors pretty easily.

Comment 4

[Nils Maier [:nmaier]]

(In reply to comment #2)
> If NSGetModule *isn't* present (which is the common case), does this cause
> build warnings or errors?

Didn't saw any new warnings/errors in my tests: Ubuntu 10.04 + gcc (4:4.4.3-1ubuntu1) + binutils (2.20.1-3ubuntu5)

(In reply to comment #3)
> This definitely doesn't block, and can be worked around by component authors
> pretty easily.

Well, first you actually need figure out what happened (which admittedly took me some time and fustration), then you need to develop some fix to make the export appear again. Decide where to put the fix (patching mozilla, or keep it in-tree). Not as easy as fiddling with visiblity("default") (which has no influence at all).
So I'm not sure about that "pretty easily" assessment of yours. ;)

Comment 5

[Nils Maier [:nmaier]]

Can it be checked in now?

Comment 6

[Justin Wood (:Callek)]

(In reply to comment #5)
> Can it be checked in now?

Only once it has approval, I do hope it GETS approval soon, imho though.

Comment 7

[:Margaret Leibovic]

http://hg.mozilla.org/mozilla-central/rev/7819e11aa46f

Comment 8

[Benjamin Smedberg]

Backed out due to Mac OS X build bustage, see bug 603930 for details.

Comment 9

[Nils Maier [:nmaier]]

Attachment: patch v1.1, add missing export back but skip darwin

This is basically the same thing as v1, but it omits the components-export-list changes which caused the bustage on mac, as described in bug 603930.

components-export-list is only used in darwin builds[1], so the patch still fixes the missing exports on linux.
It cannot fix things on mac, which would require different -exported-symbols definition files, and frankly I don't care too much about mac, nor do I have a fast-enough box to do any real development there.

Builds with this patch tested on Win7, OSX 10.6.0.4 and Linux x86_64 (Ubuntu maverik), all successful. NSGetModule correctly exported in Win7 and linux, but not darwin (see remarks above).

[1] http://mxr.mozilla.org/mozilla-central/source/configure.in#2921

Comment 10

[(no longer active)]

http://hg.mozilla.org/mozilla-central/rev/cc5a70c9e1e8