[mvapich-discuss] How do I build -O0?

[Adam Moody]

Hello MVAPICH team,
I'm trying to get a "-g -O0" build of MVAPICH2-1.4 so that I see correct 
line numbers in the MPI source under a debugger like TotalView.  I'm 
using the following settings, which I think should work based on the 
help info in the configure command:
    #!/bin/bash
    export PREFIX=`pwd`
    export CC=gcc
    export CXX=g++
    export F77=gfortran
    export F90=gfortran
    export MPICH2LIB_CFLAGS="-g -O0"
    export MPICH2LIB_CXXFLAGS="-g -O0"
    export MPICH2LIB_FFLAGS="-g -O0"
    export MPICH2LIB_F90FLAGS="-g -O0"
    export CONFIG_FLAGS="--disable-fast --enable-g=dbg 
--enable-error-checking=runtime --enable-error-messages=all 
--enable-nmpi-as-mpi"
    ./configure \
        --prefix=$PREFIX \
        --enable-sharedlibs=gcc \
        --enable-f77 --enable-f90 --enable-cxx \
        $CONFIG_FLAGS \
        --enable-debuginfo \
        --with-pmi=slurm --with-pm=no \
        --with-rdma=gen2 --with-ib-include=/usr/include 
--with-ib-lib=/usr/lib64 \
        --enable-registration-cache --enable-limic2 \
        --enable-romio --with-file-system=lustre+nfs+ufs \
        --disable-mpe --without-mpe

I'm building the MVAPICH2-1.4 tarball from:
    http://mvapich.cse.ohio-state.edu/download/mvapich2/mvapich2-1.4.tgz

It seems to do the correct thing with --enable-g=dbg and 
MPICH2LIB_CFLAGS as an extra "-g -g -O0" gets appended to the CFLAGS, 
but there is this leading "-g -O2" that I can't get rid of (see below):

=== configuring in channels/mrail 
(/usr/global/tools/mpi/checkouts/llnl/mvapich2-1.4-r3536/mvapich2-1.4/src/mpid/ch3/channels/mrail)^M
configure: running /bin/sh ./configure --disable-option-checking 
'--prefix=/usr/global/tools/mpi/checkouts/llnl/mvapich2-1.4-r3536/mvapich2-1.4'  
'--enable-sharedlibs=gcc' '--enable-f77' '--enable-f90' '--enable-cxx' 
'--disable-fast' '--enable-g=dbg' '--enable-error-checking=runtime' 
'--enable-error-messages=all' '--enable-nmpi-as-mpi' 
'--enable-debuginfo' '--with-pmi=slurm' '--with-pm=no' 
'--with-rdma=gen2' '--with-ib-include=/usr/include' 
'--with-ib-lib=/usr/lib64' '--enable-registration-cache' 
'--enable-limic2' '--enable-romio' '--with-file-system=lustre+nfs+ufs' 
'--disable-mpe' '--without-mpe' 'CC=gcc' 'F77=gfortran' 'F90=gfortran' 
'CXX=g++' 'MPICH2LIB_CFLAGS=-g -O0' 'MPICH2LIB_CXXFLAGS=-g -O0' 
'MPICH2LIB_FFLAGS=-g -O0' 'MPICH2LIB_F90FLAGS=-g -O0' 
'--enable-header-caching' 'CFLAGS=-g -O2 -g -g -O0' 'LIBS=-lpthread ' 
'CPPFLAGS=-I/usr/include ' --cache-file=/dev/null --srcdir=.

I think I could perhaps set CFLAGS explicitly to "-g -O0", but this then 
forces "-g -O0" into the MPI wrapper scripts like mpicc, which I don't 
want.  I'd just like the MPI library itself to build with -O0, not the 
application code.  Is there a way to do this?  I can't seem to find the 
right flag or environment variable.
Thanks,
-Adam