Allow re-targeting of naclports install

examples/systems/bochs-2.4.6/nacl-bochs-2.4.6.sh

 #!/bin/bash
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 # nacl-bochs-2.4.6.sh
 #
 # usage:  nacl-bochs-2.4.6.sh
 #
@@ skipping 13 matching lines @@
 source ../../../build_tools/common.sh
 
 BOCHS_EXAMPLE_DIR=${NACL_SRC}/examples/systems/bochs-2.4.6
 
 CustomConfigureStep() {
   Banner "Configuring ${PACKAGE_NAME}"
   # export the nacl tools
   export CC=${NACLCC}
   export CXX=${NACLCXX}
   export CXXFLAGS="-O2 -g -I${NACL_SDK_ROOT}/include"
-  export LDFLAGS=""
+  export LDFLAGS="${NACLPORTS_LDFLAGS}"
   if [ ${NACL_ARCH} = "pnacl" ] ; then
     export CXXFLAGS="-O3 -g"
     export LDFLAGS="-O0 -static"
   fi
   export AR=${NACLAR}
   export RANLIB=${NACLRANLIB}
   # path and package magic to make sure we call the right
   # sdl-config, etc.
-  export PKG_CONFIG_PATH=${NACL_SDK_USR_LIB}/pkgconfig
-  export PKG_CONFIG_LIBDIR=${NACL_SDK_USR_LIB}
+  export PKG_CONFIG_PATH=${NACLPORTS_LIBDIR}/pkgconfig
+  export PKG_CONFIG_LIBDIR=${NACLPORTS_LIBDIR}
   export PATH=${NACL_BIN_PATH}:${PATH};
-  export PATH="${NACL_SDK_USR_BIN}:${PATH}"
+  export PATH="${NACLPORTS_PREFIX_BIN}:${PATH}"
 
   export NACLBXLIBS="-lnacl-mounts -lpthread"
 
   # Hacky way of getting around the bochs configuration tools which don't allow
   # --whole-archive and don't allow for multiple libraries with the same name
   # on the linker line
   PWD=$(pwd)
   # TODO(bradnelson): take this out once the sdk is fixed (and do the line
   # after).
   if [ "$NACL_ARCH" = "x86_64" ]; then
@@ skipping 22 matching lines @@
   fi
   export LIBS="$LIBS -Wl,--end-group"
 
   ChangeDir ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}
   Remove ${PACKAGE_NAME}-build
   MakeDir ${PACKAGE_NAME}-build
   cd ${PACKAGE_NAME}-build
   ../configure \
     --host=nacl \
     --disable-shared \
-    --prefix=${NACL_SDK_USR} \
-    --exec-prefix=${NACL_SDK_USR} \
-    --libdir=${NACL_SDK_USR_LIB} \
-    --oldincludedir=${NACL_SDK_USR_INCLUDE} \
+    --prefix=${NACLPORTS_PREFIX} \
+    --exec-prefix=${NACLPORTS_PREFIX} \
+    --libdir=${NACLPORTS_LIBDIR} \
+    --oldincludedir=${NACLPORTS_INCLUDE} \
     --with-x=no \
     --with-x11=no \
     --with-sdl=yes \
     --with-gnu-ld
 }
 
 CustomExtractStep(){
   Banner "Untaring ${PACKAGE_NAME}.tar.gz"
   ChangeDir ${NACL_PACKAGES_REPOSITORY}
   Remove ${PACKAGE_NAME}
@@ skipping 110 matching lines @@
   DefaultBuildStep
   if [ ${NACL_ARCH} = "pnacl" ] ; then
     DefaultTranslateStep ${PACKAGE_NAME} ${PACKAGE_NAME}-build/bochs
   fi
   CustomInstallStep
   DefaultCleanUpStep
 }
 
 CustomPackageInstall
 exit 0