933892 - MFBT_APIs are getting exported from too many DLLs

Status: RESOLVED WORKSFORME

(Core :: MFBT, defect)

Description

[(Away)]

I noticed that mozglue.dll exports a bunch of WebCore::Decimal and double_conversion functions. I don't think anybody actually needs these from mozglue, but the linker has to keep them around because of the export marking. I suspect that the intent was to export those functions only from mozjs, but mozglue ends up exporting them too because mozglue happened to pull in that header (or maybe vice versa).

These changes added MFBT_API on those functions:
https://hg.mozilla.org/integration/mozilla-inbound/rev/84eb9e72b338
https://hg.mozilla.org/integration/mozilla-inbound/rev/463626bffba7

MFBT_API is either an export marker or an import marker depending on whether you defined(IMPL_MFBT):
https://hg.mozilla.org/mozilla-central/file/5bb07c1ae9f5/mfbt/Types.h#l80

When I see that kind of code pattern, I kind of expect that there would be one implementor and the rest are consumers. But it seems that both JS and mozglue want to IMPL_MFBT:
http://mxr.mozilla.org/mozilla-central/search?string=IMPL_MFBT

Comment 1

[Mike Hommey [:glandium]]

(In reply to David Major [:dmajor] from comment #0)
> When I see that kind of code pattern, I kind of expect that there would be
> one implementor and the rest are consumers. But it seems that both JS and
> mozglue want to IMPL_MFBT:
> http://mxr.mozilla.org/mozilla-central/search?string=IMPL_MFBT

That's a red herring. JS only does that for standalone builds, where it builds mfbt itself.

Comment 2

[(Away)]

This appears to have been fixed by bug 870401.