Compiler flag -fwrapv is not known to GCC 3.3.5

[Christian Kellermann]

This breaks the build on OpenBSD. (Yes the compiler is ancient). Which is the recommended gcc version that should be used? OpenBSD has a newer GCC in its ports (4.2.x 4.3.x) so it is no problem if this fact is set in stone (aka the readme) somewhere. Or have I missed it? Removing this flag from the makefile of course fixes the issue.

What I gathered from other sources on the net is that versions above or equal to 4.2.4 work ok with it, while 4.1 versions do have issues.
Then again maybe it is just the linux kernel. Source: ​https://patchwork.kernel.org/patch/35097/

[Christian Kellermann]

This has been introduced by

commit 52cad50d492e2e599bb845dbcfc514274eea5aac
Author: felix <felix@…>
Date: Thu Sep 16 04:40:25 2010 -0400

added -fwrapv to gcc options

Sorry for not catching this earlier. I have setup a cron job that does a daily build now.

[felix winkelmann]

Well, I'm not sure what to do. Would it be acceptable to require 4.2 or higher? As I understand, this option enables "normal" overflow of integer arithmetic (2s complement), which I think (just think) is required for the fixnum-overflow detection (Gambit uses this flag and I recall readinf somewhere on its mailing list about the flag being "required for correctness", whatever that means).

[felix winkelmann]

Christian, does the system run ok when you remove this flag?

[Christian Kellermann]

diff to disable flag when building on openbsd

[Christian Kellermann]

Attached is a patch that excludes the flag when building on OpenBSD. Maybe a check against the compiler version is better though...

Tested against 4.6.2 it seems to work, all tests run fine.

[felix winkelmann]

Thanks, Christian. Patch is applied (experimental).

[felix winkelmann]

Milestone 4.7.0 deleted

[felix winkelmann]

Milestone 4.8.0 deleted