39268 - xptc on FreeBSD 3.x with gcc > 2.7 doesn't work

Status: RESOLVED FIXED

(Core :: XPCOM, defect, P3)

Description

[Joerg.Brunsmann]

Here's a patch:

Index: xpcom/reflect/xptcall/src/md/unix/xptc_platforms_unixish_x86.h
===================================================================
RCS file:
/cvsroot/mozilla/xpcom/reflect/xptcall/src/md/unix/xptc_platforms_unixish_x86.h,v
retrieving revision 1.6
diff -r1.6 xptc_platforms_unixish_x86.h
62c62
< #elif __FreeBSD_version == 340000
---
> #elif (__FreeBSD_version == 340000) && (__GNUC__ == 2) && (__GNUC_MINOR__ ==
7)


Can you please check it in? Thanks.

Comment 1

[Scott Collins]

I'll handle this

Comment 2

[Scott Collins]

patch checked in

Comment 3

[Tracy Walker [:tracy]]

- Per last comments, age of bug, and no reopen - Marking Verified/Fixed.  Please 
reopen if still a problem. 

Comment 4

[Jonathan Lennox]

This fix should be changed to apply to anything in the 3.x series, not just 3.4.
The obvious fix would be to say (__FreeBSD_version < 400000); I'll test
this on my 3.5.1 box to confirm it (both for the system gcc 2.7.2.3 and gcc
2.95.2).

Comment 5

[Jonathan Lennox]

Okay, I've done some more analysis of this.  Here's what's going on; it's why
there's been so much confusion over FreeBSD xptc.

/usr/bin/g++ in every released version of FreeBSD has used CFront-style object
layout.  In 3.x, /usr/bin/g++ is gcc 2.7.2.3; in 4.x releases and in
5.0-CURRENT, /usr/src/contrib/gcc/config/freebsd.h has DEFAULT_VTABLE_THUNKS
#undef'd.

The complications arise from two facts.  First of all, there was a period of
time during the development of 4.0-CURRENT (from September 1999 to January
2000) when /usr/bin/g++ used thunks.  This was changed before 4.0-RELEASE, but
people in the past were compiling Mozilla on 4.0-CURRENT.

Secondly, the versions of gcc 2.95 from the FreeBSD ports collection
(/usr/ports/lang/egcs, which gets installed as /usr/local/bin/g++295) *do*
use thunks.  Anyone wanting to compile with gcc 2.95 on FreeBSD 3.x uses
these version.  (This will also happen, I believe, if you use the stock
FSF gcc 2.95.x.)

Fortunately, I believe all this stuff can be disambiguated with the
preprocessor symbol __FreeBSD_cc_version.  This is only defined by the
/usr/bin versions of the compiler, so its absence indicates that you're using
a ported or FSF version of gcc.  In the two versions of the system compiler
which used thunks, its value was 400002 and 400003.

I've created a patch which implements this.  It works for me on FreeBSD 3.5.1
using both /usr/bin/g++ and /usr/local/bin/g++295.  It needs testing on 4.x
and 5.x, though.

Comment 6

[Jonathan Lennox]

Attachment: Patch to untangle FreeBSD object layout

Comment 7

[Scott Collins]

jband: I'm not sure why this bug is assigned to me, though I'm capable of 
checking in a patch ... should you own this?  or someone else?

Comment 8

[John Bandhauer]

shaver gets these. He's been actively working with folks lately to get all these 
xptcall x86 Unixish platform issues under control.

Comment 9

[pete collins]

Compiles and runs for me on 4.) RELEASE

--pete

Comment 10

[Mike Shaver (:shaver emeritus)]

One down, 5.x to go.

(And approval, natch.)

Comment 11

[Pascal Hofstee]

I applied the patch ... and as You can see ... my Tinderbox build is still All
Green :-)

I'd say ... it works

Comment 12

[Jonathan Lennox]

For those who don't follow netscape.public.mozilla.unix (or tinderbox)
religiously, Pascal's machine shadowmere is the FreeBSD 5.0-CURRENT tinderbox.
Thanks, Pascal!

Comment 13

[Mike Shaver (:shaver emeritus)]

Sorry for not noticing earlier that we made 5.0 work as well!  OK, can someone
other than me review, and then I'll sr= and check it in?

Comment 14

[Mike Shaver (:shaver emeritus)]

*** Bug 33739 has been marked as a duplicate of this bug. ***

Comment 15

[Mike Shaver (:shaver emeritus)]

jband? scc? have any spare review cycles?

Comment 16

[Mike Shaver (:shaver emeritus)]

This is now fixed in the tip and the 0.8.1 branch.  Sorry for the extreme delay. =(

If you'd like to contribute a milestone build for 0.8.1, please read
http://www.mozilla.org/build/distribution.html and send me email about where to
find the completed build.