329615 – dev-libs/gmp requires CPPFLAGS="-fexceptions" in order to support sys-devel/gcc with USE=graphite (suggested patches included)

Bug 329615 - dev-libs/gmp requires CPPFLAGS="-fexceptions" in order to support sys-devel/gcc with USE=graphite (suggested patches included)

Summary: dev-libs/gmp requires CPPFLAGS="-fexceptions" in order to support sys-devel/g...

Status:	RESOLVED DUPLICATE of bug 294978

Alias:	None

Product:	Gentoo Linux
Classification:	Unclassified
Component:	New packages (show other bugs)
Hardware:	All Linux

Importance:	High normal (vote)
Assignee:	Gentoo Toolchain Maintainers

URL:
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Keywords:

Depends on:
Blocks:

Reported:	2010-07-23 18:14 UTC by Phil Stracchino (Unix Ronin)
Modified:	2010-07-24 21:37 UTC (History)
CC List:	1 user (show)

See Also:
Package list:
Runtime testing required:	---

Attachments
Patch for dev-libs/gmp ebuild (gmp-ebuild.diff,920 bytes, patch) 2010-07-23 18:15 UTC, Phil Stracchino (Unix Ronin)	Details \| Diff
Patch for dev-libs/ppl ebuild (ppl-ebuild.diff,554 bytes, patch) 2010-07-23 18:16 UTC, Phil Stracchino (Unix Ronin)	Details \| Diff
View All Add an attachment (proposed patch, testcase, etc.)

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Description Phil Stracchino (Unix Ronin) 2010-07-23 18:14:00 UTC

Recent versions of sys-devel/gcc have an option to use the new 'graphite' loop optimization feature of gcc.  This requires dev-libs/ppl and dev-libs/cloog-ppl, in addition to the dev-libs/gmp already required by sys-devel/gcc.  However, dev-libs/ppl REQUIRES that dev-libs/gmp be built using CPPFLAGS="-fexceptions".  There is currently no mechanism to enable CPPFLAGS="-fexceptions" *only* for dev-libs/gmp other than by doing it manually every time dev-libs/gmp is compiled.

I have found no package that uses dev-libs/gmp for which compilation of dev-libs/gmp with CPPFLAGS="-fexceptions" is harmful.  However, there do appear to be some packages (including, it appears, media-video/vlc) which themselves fail to build in the presence of CPPFLAGS="-fexceptions".  (It looks as though the problem is the Qt4 moc tool does not get along with -fexceptions.)

I see two obvious possible solutions to this issue:

(a) [simpler, PROBABLY safe]  Simply add CPPFLAGS="-fexceptions" to dev-libs/gmp by default.

(b) [better, safe]  Add an exceptions USE flag to dev-libs/gmp, and add dev-libs/gmp[exceptions] to the dependencies for dev-libs/ppl

I have tested the latter and it seems to work correctly.

Reproducible: Always

Comment 1 Phil Stracchino (Unix Ronin) 2010-07-23 18:15:23 UTC

Created attachment 239941 [details, diff]
Patch for dev-libs/gmp ebuild

Comment 2 Phil Stracchino (Unix Ronin) 2010-07-23 18:16:04 UTC

Created attachment 239943 [details, diff]
Patch for dev-libs/ppl ebuild

Comment 3 Rafał Mużyło 2010-07-24 01:58:22 UTC

On one hand, there's bug 294978, on the other, there's seems to be a misunderstanding there.

Though, '-fexceptions' seems to belong to CXXFLAGS, not preprocessor.

Do you have any sources more verbose than that configure message on *why*
is that needed and why the other upstream  doesn't even suggest it ?

Comment 4 Ryan Hill (RETIRED) gentoo-dev

2010-07-24 03:14:06 UTC

Your gmp isn't being built correctly.

*** This bug has been marked as a duplicate of bug 294978 ***

Comment 5 Phil Stracchino (Unix Ronin) 2010-07-24 21:37:42 UTC

Rafal, I put -fexceptions in CPPFLAGS because that's where the configure warning from dev-libs/ppl told me to.

Ryan, my dev-libs/gmp is being built correctly, but I had to set it up by hand to do so.  I was proposing these small changes so that other people wanting to use sys-devel/gcc[graphite] would have an existing mechanism to set it up correctly.