Re: gcc bootstrapping problem

[Ralf Corsepius]

On Sat, 2004-09-18 at 18:41, Post, Mark K wrote:
> Hi,
> 
> I'm trying to create a native 64-bit compiler for Slack/390.  I downloaded
> some existing ones from the Fedora project to get me started.  I ran into a
> problem with them.  That is, far, far along into the build, the make process
> starts to configure in the s390x-slackware-linux/libjava/ directory, and it
> invokes ltconfig.  The ltconfig script issues this command, and gets the
> error shown:
> ltconfig:1487:  /tmp/build-gcc-3.3.4-s390x-1/gcc.build.lnx/gcc/xgcc
> -shared-libgcc -B/tmp/build-gcc-3.3.4-s390x-1/gcc.build.lnx/gcc/ -nostdinc++
> -L/tmp/build-gcc-3.3.4-s390x-1/gcc.build.lnx/s390x-slackware-linux/libstdc++
> -v3/src
> -L/tmp/build-gcc-3.3.4-s390x-1/gcc.build.lnx/s390x-slackware-linux/libstdc++
> -v3/src/.libs -B/usr/s390x-slackware-linux/bin/
> -B/usr/s390x-slackware-linux/lib/ -isystem
> /usr/s390x-slackware-linux/include -o conftest -g -O2 -D_GNU_SOURCE
> -fno-builtin -fno-rtti -fno-exceptions   conftest.cc conftstm.o 1>&5
> conftstm.o(.eh_frame+0x11): In function `main':
> /tmp/build-gcc-3.3.4-s390x-1/gcc.build.lnx/s390x-slackware-linux/libjava/con
> ftest.cc:9: undefined reference to `__gxx_personality_v0'
> collect2: ld returned 1 exit status
> 
> According to a conversation I had with a gcc developer, the issue is
> "ltconfig is
> attempting to use the C driver (xgcc) to build and link a C++ program; this
> is the reason of the failure."
This is only half of the story.

Yes, it is using "xgcc", but "xgcc" is not the "C driver". "xgcc" is a
temporary, gcc-buildtree local version of the "to-be-built gcc".
In the log above, they are invoking xgcc in such a way that it expects
"C-code", i.e. it implicitly calls the "C-driver"

To be able to compile and link C++ files, they either must be using a
corresponding temporary, local "xg++" (AFAIK, such thing does not exist)
or pass the appropriate language options to xgcc (Probably something
like "xgcc -x c++").

So, IMO, this is a problem in GCC's way to set up CXX.

> I'm using libtool 1.5.6 on this system.
Are you a gcc-developer rebuilding auto*tool generated files inside of
GCC's sourcetree (Bootstrapping gcc's sourcedir) or a user trying to
build gcc (bootstrapping gcc)? In the latter case, this should not
matter, because GCC ships with prebuild files, you don't really want to
touch. 

>   I tried searching for prior bug
> reports, but didn't come across any.  It was pretty late at night, though,
> and I could have missed one.
> 
> If this is a known issue, I'll upgrade to the latest released version.
IMO, this is not a libtool bug, but a problem with GCC's configure
scripts.

Ralf