Re: libsigsegv on LinuxFromScratch

[Bruce Dubbs]

On 9/18/20 6:47 PM, Bruce Dubbs wrote:
> On 9/18/20 6:24 PM, Bruno Haible wrote:
> > Bruce Dubbs wrote in
> > <https://lists.gnu.org/r/grep-devel/2020-09/msg00052.html>
> > <https://lists.gnu.org/r/grep-devel/2020-09/msg00053.html> :
> >
> > > > checking for libsigsegv... yes
> > > > checking how to link with libsigsegv... -lsigsegv
> > >
> > > I get:
> > >
> > > checking for libsigsegv... yes
> > > checking how to link with libsigsegv... /usr/lib/libsigsegv.so
> > > /usr/lib/libc.a

Here is some background.  When we build grep on LFS, we normally do not 
have either pcre or libsegsev installed.  It has built fine for years. 
We have had no complaints.

In the latest grep-3.4-almost.31-fe6c I have been testing after both 
pcre and libsigsevv have been.  I haven't been installing the new grep 
versions, only going through make check.

Here is what I found.

If ./configure is run without options, the build and checks are fine.

If ./configure is run with --prefix=/usr with both libsigsegv and 
/usr/lib/libc.a are present, configure gives:

configure:10063: checking for libsigsegv
configure:10086: gcc -o conftest -g -O2   conftest.c 
/usr/lib/libsigsegv.so /usr/lib/libc.a  >&5
configure:10086: $? = 0
configure:10097: result: yes
configure:10104: checking how to link with libsigsegv
configure:10106: result: /usr/lib/libsigsegv.so /usr/lib/libc.a

Which causes grep to segfault immediately.

If ./configure is run with --prefix=/usr AND --without-libsigsegv-prefix
the result is:

configure:10063: checking for libsigsegv
configure:10086: gcc -o conftest -g -O2   conftest.c  -lsigsegv >&5
configure:10086: $? = 0
configure:10097: result: yes
configure:10104: checking how to link with libsigsegv
configure:10106: result: -lsigsegv

And the results of the checks are as expected.

If I move all libtool .la files (I really dislike libtool) out of the 
way, then things are fine again with just --prefix=/usr:

configure:10063: checking for libsigsegv
configure:10086: gcc -o conftest -g -O2   conftest.c 
/usr/lib/libsigsegv.so  >&5
configure:10086: $? = 0
configure:10097: result: yes
configure:10104: checking how to link with libsigsegv
configure:10106: result: /usr/lib/libsigsegv.so

So the bottom line is there is something interacting between libtool and 
teh default libsigsegv procedures, however none of the .la files 
references libc.a directly.

I hope this helps.

  -- Bruce