Restrict compiler selection to MPICH_{CC,CXX,F77}, allowing CC, et. al risks an infinite recursion.

git-svn-id: https://svn.mcs.anl.gov/repos/darshan/trunk@703 3b7491f3-a168-0410-bf4b-c445ed680a29

darshan-runtime/darshan-gen-cc.pl.in

@@ -117,10 +117,7 @@ print OUTPUT<<"EOF";
 # Show is set to echo to cause the compilation command to be echoed instead 
 # of executed.
 Show=
-CC=\${CC:-"$CC"}
-if [ -n "\$MPICH_CC" ] ; then
-    CC=\$MPICH_CC
-fi
+CC=\${MPICH_CC:-"$CC"}
 
 EOF
 

darshan-runtime/darshan-gen-cxx.pl.in

@@ -117,10 +117,7 @@ print OUTPUT<<"EOF";
 # Show is set to echo to cause the compilation command to be echoed instead 
 # of executed.
 Show=
-CXX=\${CXX:-"$CXX"}
-if [ -n "\$MPICH_CC" ] ; then
-    CXX=\$MPICH_CXX
-fi
+CXX=\${MPICH_CXX:-"$CXX"}
 
 EOF
 

darshan-runtime/darshan-gen-fortran.pl.in

@@ -117,10 +117,7 @@ print OUTPUT<<"EOF";
 # Show is set to echo to cause the compilation command to be echoed instead 
 # of executed.
 Show=
-FC=\${F77:-"$FC"}
-if [ -n "\$MPICH_F77" -o -n "\$MPICH_F90" ] ; then
-    FC=\${MPICH_F90:-\$MPICH_F77}
-fi
+FC=\${MPICH_F77:-"$FC"}
 
 EOF