#! /bin/sh

: ${R_SRC_DIR=~/src/R}

args="--cache-file=config.cache \
--enable-R-shlib --enable-memory-profiling \
DEFS='-DUSE_TYPE_CHECKING_STRICT -D_FORTIFY_SOURCE=3' LIBnn=lib"
## DEFS='-DUSE_TYPE_CHECKING_STRICT' LIBnn=lib"
## --with-valgrind-instrumentation=1

## Compilers to use.
## Use configure defaults (gcc/g++/gfortran).
compilers=
flavor="-fg"
extra=false
blas=
## --with-blas=no is the current default ...
##   blas="--with-blas=no"

## <NOTE>
## If needed, the flavors could set their own user Makevars file via the
## environment variable R_MAKEVARS_USER.
## </NOTE>

while test -n "${1}"; do
  case "${1}" in
    -r)
      R_SRC_DIR=~/src/apps/R/r-release/R ;;
    -p)
      R_SRC_DIR=~/src/apps/R/r-patched/R ;;
    -d)
      R_SRC_DIR=~/src/apps/R/r-devel/R ;;
    -s)
      R_SRC_DIR="${2}"
      shift ;;
    -m)
      args="${args} --enable-maintainer-mode" ;;
    -x)
      extra=true ;;
    -bo)
      blas="--with-blas=-lopenblas --with-lapack=no" ;;
    -ba)
      blas="--with-blas='-lcblas -lf77blas -latlas' --with-lapack=no" ;;
    -bm)
      blas="--with-blas='-lmkl_gf_lp64 -lmkl_core -lmkl_sequential' --with-lapack" ;;
    -bi)
      blas="--with-blas=no --with-lapack=no" ;;
    -b)
      blas="--with-blas=yes --with-lapack=yes" ;;
    -v)
      args="${args} --with-valgrind-instrumentation=2 --with-system-valgrind-headers" ;;
    -f*)
      flavor="${1}" ;;
    *)
      args="${args} ${1}" ;;
  esac
  shift
done

args="${args} ${blas}"

case "${flavor}" in    
  -fg*)
    ## flavor: gcc
    ## <NOTE>
    ## When primarily using clang for testing, configure with
    ## --disable-long-double so that we can emulate hardware with no
    ## excess fp precision results:
    ##   args="${args} --disable-long-double"
    ## </NOTE>
    v=`expr "${flavor}" : ".*/\\(.*\\)"`
    gcc_series_is_snap=false
    case "${v}" in 
      snap)
	gcc_series_is_snap=true ;;
    esac
    PREFIX=
    SUFFIX=
    if test "${gcc_series_is_snap}" = "true"; then
      PREFIX="/usr/lib/gcc-snapshot/bin/"
    elif test -n "${v}"; then
      SUFFIX="-${v}"
    fi
    ## C standard.
    ## See <https://gcc.gnu.org/onlinedocs/gcc/Standards.html>.
    ## For GCC 11, if no C language dialect options are given, is
    ## -std=gnu17.
    ## Previously, using c11 instead of gnu11 for gcc broke many
    ## packages. 
    ##   CCSTD="-std=c11"
    CCSTD=
    ## C++ standard.
    ## See <https://gcc.gnu.org/projects/cxx-status.html>:
    ## * C++17 features are available since GCC 5. This mode is the
    ##   default in GCC 11. 
    ## * C++14 is the default in GCC 6.1 up until GCC 10 (including);
    ##   it can be explicitly selected with the -std=c++14 command-line
    ##   flag, or -std=gnu++14 to enable GNU extensions as well. 
    ## * C++98 is the default in GCC versions prior to 6.1; 
    ##   it can be explicitly selected with the -std=c++98 command-line
    ##   flag, or -std=gnu++98 to enable GNU extensions as well.
    ## As of 2021-12-17, R will configure for C++14 if available: to
    ## force a particular standard, use e.g.
    ## CXXSTD="-std=gnu++17"
    if test "${extra}" = "true"; then
      EXTRAC="-fsanitize=address,undefined -fno-omit-frame-pointer"
      EXTRACXX="-fsanitize=address,undefined,bounds-strict -fno-omit-frame-pointer"
      EXTRAF="-fsanitize=address"
      ## As of 2015-09-07, compilation with ASAN/UBSAN fails on the
      ## #pragma omp parallel in /src/library/stats/src/distance.c:
      ## Hence, disable OpenMP for the time being.
      args="--disable-openmp ${args}"
    else
      EXTRAC=
      EXTRACXX=
      EXTRAF=
    fi
    CC="\"${PREFIX}gcc${SUFFIX} ${EXTRAC}\""
    ## CC="\"${PREFIX}gcc${SUFFIX} ${CCSTD} ${EXTRAC}\""
    CXX="\"${PREFIX}g++${SUFFIX} ${EXTRACXX}\""
    ## CXX="\"${PREFIX}g++${SUFFIX} ${CXXSTD} ${EXTRAC}\""
    F77="\"${PREFIX}gfortran${SUFFIX} ${EXTRAF}\""
    FC="\"${PREFIX}gfortran${SUFFIX} ${EXTRAF}\""
    OBJC="${PREFIX}gcc${SUFFIX}"
    compilers="CC=${CC} CXX=${CXX} F77=${F77} FC=${FC} OBJC=${OBJC}"
    ## compilers="CC=${CC} CXX=${CXX} CXXSTD=${CXXSTD} F77=${F77} FC=${FC} OBJC=${OBJC}"
    if test "${gcc_series_is_snap}" = "true"; then
      compilers="${compilers} LDFLAGS=-L/usr/lib/gcc-snapshot/lib"
      ## compilers="${compilers} LDFLAGS=-Wl,-rpath,/usr/lib/gcc-snapshot/lib"
    fi
    if test "${extra}" = "true"; then
      compilers="${compilers} MAIN_LDFLAGS=\"-fsanitize=address,undefined\""
    fi
    ;;
  -fc*)
    ## flavor: clang
    ## Using '-stdlib=libc++' does not always work for packages linking
    ## against system libraries built against -lstdc++ (e.g., JAGS).
    ## CXXSTD="-std=c++98"
    ## CXXSTD="-std=c++11"
    vc=`expr "${flavor}" : "[^/]*/\\([^/]*\\)\\(/.*\\)\\?"`
    vg=`expr "${flavor}" : "[^/]*/[^/]*/\\(.*\\)"`
    if test -n "${vc}"; then
      SUFFIX="-${vc}"
    else
      SUFFIX=
    fi
    if test "${extra}" = "true"; then
      EXTRAC="-fsanitize=address,undefined -fno-sanitize=float-divide-by-zero -fno-sanitize=alignment  -fno-omit-frame-pointer"
      EXTRACXX="-fsanitize=address,undefined -fno-sanitize=float-divide-by-zero -fno-sanitize=alignment -fno-omit-frame-pointer -frtti"
    else
      EXTRAC=
      EXTRACXX=
    fi
    CC="\"clang${SUFFIX} ${EXTRAC}\""
    CXX="\"clang++${SUFFIX} ${EXTRACXX}\""
    ## CXX="\"clang++${SUFFIX} ${CXXSTD} ${EXTRAC}\""
    compilers="CC=${CC} CXX=${CXX}"
    ## compilers="CC=${CC} CXX=${CXX} CXXSTD=${CXXSTD}"
    ## ## <FIXME>
    ## ## Added 2018-04-03 to avoid compilation errors for
    ## ## RcppArmadillo: remove eventually ...?
    ## CXX11STD="-std=c++11"
    ## CXX14STD="-std=c++14"
    ## compilers="${compilers} CXX11STD=${CXX11STD} CXX14STD=${CXX14STD}"
    ## ## </FIXME>
    if test "${extra}" = "true"; then
      compilers="${compilers} MAIN_LD=\"clang++${SUFFIX} -fsanitize=undefined,address\""
    fi
    ## Clang can compile Objective-C and Objective-C++, but needs a
    ## runtime and the corresponding headers (e.g., 'objc/Object.h'):
    ## on Debian/Ubuntu, the latter are currently only available in
    ## the respective GCC version-specific header directories (e.g.,
    ## '/usr/lib/gcc/x86_64-linux-gnu/4.9/include'), and hence not
    ## really usable for Clang.
    ## One could try using the GNUstep Objective-C runtime and headers
    ## (libobjc2 available from http://download.gna.org/gnustep/) but
    ## this is not available for Debian/Ubuntu.
    ## Hence, use GCC for Objective-C and Objective-C++.
    ## What a nuisance ...
    ## Last updated: 2014-09-10.
    if test -n "${vg}"; then
      SUFFIX="-${vg}"
    else
      SUFFIX=
    fi
    F77="gfortran${SUFFIX}"
    FC="gfortran${SUFFIX}"
    OBJC="gcc${SUFFIX}"
    OBJCXX="g++${SUFFIX}"
    compilers="${compilers} F77=${F77} FC=${FC} OBJC=${OBJC} OBJCXX=${OBJCXX}"
    ;;
esac

eval ${R_SRC_DIR}/configure ${args} ${compilers}