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Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2"
From: |
Allan McRae |
Subject: |
Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2" |
Date: |
Wed, 08 May 2013 15:17:02 +1000 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130428 Thunderbird/17.0.5 |
On 08/05/13 15:01, Paul Eggert wrote:
> On 05/07/2013 08:49 PM, Anatol Pomozov wrote:
>
>> Linux Arch distributive recently added following compilation flags to
>> CPPFLAGS: "-D_FORTIFY_SOURCE=2 -O2". Unfortunately it breaks autoconf based
>> projects such as gdb, gcc, ...
>>
>> The issue is that autoconf compiles some programs to find whether system
>> has headers. And to compile it uses only preprocessor defines from CPPFLAGS
>> (-D_FORTIFY_SOURCE=2 in case of Arch). recent versions of glibc produces a
>> warning when it compiles apps with _FORTIFY_SOURCE but without -O2.
>
> Sorry, I don't understand. If CPPFLAGS="-D_FORTIFY_SOURCE=2 -O2",
> and if 'configure' uses preprocessor defines from CPPFLAGS,
> then 'configure' should be using -D_FORTIFY_SOURCE=2 -O2.
> But you seem to be implying that 'configure' is using -D_FORTIFY_SOURCE=2
> without -O2. How can this be?
Our distribution packages are compiled with:
CPPFLAGS="-D_FORTIFY_SOURCE=2"
CFLAGS="-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector
--param=ssp-buffer-size=4"
So when both CPPFLAGS and CFLAGS are passed there is no issue.
I have not looked into this in great detail yet, but it seems some
configure scripts have this in them:
ac_cpp='$CPP $CPPFLAGS'
and this is used to test for header presence. Note I said some
configure scripts - I have not figured out why others do not use
CPPFLAGS in this test.
>> recent versions of glibc produces a
>> warning when it compiles apps with _FORTIFY_SOURCE but without -O2
>
> That's a real problem, which will break lots of things.
> Fix that, and your Autoconf issue will go away.
I don't agree that the glibc warning is an issue. Unless you use
-Werror (bad) or check for any warning rather than a specific one.
Allan
- Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Anatol Pomozov, 2013/05/07
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Paul Eggert, 2013/05/08
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2",
Allan McRae <=
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Ralf Corsepius, 2013/05/08
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Anatol Pomozov, 2013/05/08
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Paul Eggert, 2013/05/08
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Allan McRae, 2013/05/08
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Eric Blake, 2013/05/08
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Allan McRae, 2013/05/09
- Re: Autoconf does not like "-D_FORTIFY_SOURCE=2 -O2", Paul Eggert, 2013/05/08