configure

#!/bin/sh
# Anticonf (tm) script by Jeroen Ooms (2015)
# This script will query 'pkg-config' for the required cflags and ldflags.
# If pkg-config is unavailable or does not find the library, try setting
# INCLUDE_DIR and LIB_DIR manually via e.g:
# R CMD INSTALL --configure-vars='INCLUDE_DIR=/.../include LIB_DIR=/.../lib'

# Library settings
PKG_CONFIG_NAME="libxml-2.0"
PKG_DEB_NAME="libxml2-dev"
PKG_RPM_NAME="libxml2-devel"
PKG_CSW_NAME="libxml2_dev"
PKG_TEST_HEADER="<libxml/tree.h>"
PKG_LIBS="-lxml2"

OS_TYPE=`uname -s`
OS_VERSION=`uname -r | cut -d '.' -f 1`

# Note that cflags may be empty in case of success
if [ "$INCLUDE_DIR" ] || [ "$LIB_DIR" ]; then
  echo "Found INCLUDE_DIR and/or LIB_DIR!"
  PKG_CFLAGS="-I$INCLUDE_DIR $PKG_CFLAGS"
  PKG_LIBS="-L$LIB_DIR $PKG_LIBS"
else
  # Use xml2-config if available
  xml2-config --version >/dev/null 2>&1
  if [ $? -eq 0 ]; then
    PKGCONFIG_CFLAGS=`xml2-config --cflags`
    PKGCONFIG_LIBS=`xml2-config --libs`

    # MacOS versions El Capitan and later ship a xml2-config which appends `xcrun
    # --show-sdk-path` to the xml2-config. So we remove it if it is present.
    # (https://stat.ethz.ch/pipermail/r-sig-mac/2016-September/012046.html)
    if [ "$OS_TYPE" = "Darwin" ] && [ "$OS_VERSION" -gt "13" ] && [ "$OS_VERSION" -lt "17" ]; then
      PKGCONFIG_CFLAGS=`echo $PKGCONFIG_CFLAGS | perl -pe "s{\Q\`xcrun -show-sdk-path\`\E}{}"`
      PKGCONFIG_LIBS=`echo $PKGCONFIG_LIBS | perl -pe "s{\Q\`xcrun -show-sdk-path\`\E}{}"`
    fi

    # Fix a missing libxml2 directory on the requested include directory
    # https://github.com/r-lib/xml2/issues/296
    if [ "${OS_TYPE}" = "Darwin" ] && echo "${PKGCONFIG_CFLAGS}" | grep -sq "/usr/include$"; then
      PKGCONFIG_CFLAGS="$PKGCONFIG_CFLAGS/libxml2"
    fi

  else
    pkg-config --version >/dev/null 2>&1
    if [ $? -eq 0 ]; then
      PKGCONFIG_CFLAGS=`pkg-config --cflags $PKG_CONFIG_NAME`
      PKGCONFIG_LIBS=`pkg-config --libs $PKG_CONFIG_NAME`
    fi
  fi

  if [ "$PKGCONFIG_CFLAGS" ] || [ "$PKGCONFIG_LIBS" ]; then
    echo "Found pkg-config cflags and libs!"
    PKG_CFLAGS=${PKGCONFIG_CFLAGS}
    PKG_LIBS=${PKGCONFIG_LIBS}
  fi
fi

# Find compiler
CC=`${R_HOME}/bin/R CMD config CC`
CFLAGS=`${R_HOME}/bin/R CMD config CFLAGS`
CPPFLAGS=`${R_HOME}/bin/R CMD config CPPFLAGS`

# For debugging
echo "Using PKG_CFLAGS=$PKG_CFLAGS"
echo "Using PKG_LIBS=$PKG_LIBS"

# Test configuration
echo "#include $PKG_TEST_HEADER" | ${CC} ${CPPFLAGS} ${PKG_CFLAGS} ${CFLAGS} -E -xc - >/dev/null 2>&1 || R_CONFIG_ERROR=1;

# Customize the error
if [ $R_CONFIG_ERROR ]; then
  echo "------------------------- ANTICONF ERROR ---------------------------"
  echo "Configuration failed because $PKG_CONFIG_NAME was not found. Try installing:"
  echo " * deb: $PKG_DEB_NAME (Debian, Ubuntu, etc)"
  echo " * rpm: $PKG_RPM_NAME (Fedora, CentOS, RHEL)"
  echo " * csw: $PKG_CSW_NAME (Solaris)"
  echo "If $PKG_CONFIG_NAME is already installed, check that 'pkg-config' is in your"
  echo "PATH and PKG_CONFIG_PATH contains a $PKG_CONFIG_NAME.pc file. If pkg-config"
  echo "is unavailable you can set INCLUDE_DIR and LIB_DIR manually via:"
  echo "R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'"
  echo "--------------------------------------------------------------------"
  exit 1;
fi

# Write to Makevars
sed -e "s|@cflags@|$PKG_CFLAGS|" -e "s|@libs@|$PKG_LIBS|" src/Makevars.in > src/Makevars

# Success
exit 0