Re: [Qemu-devel] Configuring qemu on Solaris

[Juergen Keil <jk@tools.de>]

Andreas Färber <andreas.faerber@web.de> wrote:

> The following part of configure is triggered on a fully-updated  
> Solaris 10 8/07 amd64:
> 
> #
> # Solaris specific configure tool chain decisions
> #
> if test "$solaris" = "yes" ; then
>    #
>    # gcc for solaris 10/fcs in /usr/sfw/bin doesn't compile qemu  
> correctly
>    # override the check with --disable-gcc-check
>    #
>    if test "$solarisrev" -eq 10 -a "$check_gcc" = "yes" ; then
>      solgcc=`which $cc`
>      if test "$solgcc" = "/usr/sfw/bin/gcc" ; then
>        echo "Solaris 10/FCS gcc in /usr/sfw/bin will not compiled qemu  
> correctly."
>        echo "please get gcc-3.4.3 or later, from www.blastwave.org  
> using pkg-get -i gcc3"
>        echo "or get the latest patch from SunSolve for gcc"
>        exit 1
>      fi
>    fi
> 
> Depending on the path of gcc, configure bails out. The text appears to  
> indicate that "the latest patch [...] for gcc", whichever that may be,  
> fixes some compilation issue.
> Since the script does not try to detect the presence of such a patch,  
> can we remove the exit and keep the text as a warning only?
> Or can someone comment on what the corresponding Solaris patch id or  
> gcc version is in order to make this conditional? The system gcc  
> version is 3.4.3 here and it appears to compile fine.

IIRC, problem was a code generation issue with the specific version of
gcc 3.4.3 (includes some patches from Sun; /usr/sfw/bin/gcc) that is
included with Solaris 10 x86.  qemu would compile just fine (32-bit x86
binary), but would crash at run time.


The problematic version of gcc refused to eliminate the frame pointer
for a function like this:

==============================================
#include <setjmp.h>

jmp_buf env;

void
func(void)
{
        longjmp(env, 1);
}
==============================================

% /usr/sfw/bin/gcc -O2 -fomit-frame-pointer -S xx.c
% cat xx.s
        .file   "xx.c"
        .text
        .p2align 2,,3
.globl func
        .type   func, @function
func:
        pushl   %ebp                       <<<<<<<<<<<<<<<<<<<<<<<
        movl    %esp, %ebp                 <<<<<<<<<<<<<<<<<<<<<<<
        subl    $16, %esp
        pushl   $1
        pushl   $env
        call    longjmp
        .size   func, .-func
        .comm   env,40,32
        .ident  "GCC: (GNU) 3.4.3 (csl-sol210-3_4-branch+sol_rpath)"

==============================================


I'm not sure if there is actually a patch id that we could check for
in "showrev -p" output.


But maybe the configure script could look at "gcc --version" output;
I guess if it finds "(csl-sol210-3_4-branch+sol_rpath)", configure should
complain.  

Current opensolaris comes with "gcc (GCC) 3.4.3 (csl-sol210-3_4-20050802)",
and this version eliminates the frame pointer in the above sample code,
and is able to compile a working qemu 32-bit x86 binary.