configure

#!/bin/sh
#
# This file is NOT generated (e.g. don't look for configure.ac).
#
# TODO:
#  + sanitize/filter GASNET_CONFIGURE_ARGS ??

##
## Begin portable (no bash-isms) logic to check for correct shell.
## We try to reexec with bash if present in $PATH
##

# Note tcsh graciously yields 'BASH_VERSION: Undefined variable' before giving up here.
if test -z "$BASH_VERSION"; then
  if test -z "$UPCXX_REEXEC"; then
    exec env UPCXX_REEXEC=1 bash "$0" "$@"
  fi
fi

# Issue 364: try to avoid /bin/sh that enables bash POSIX mode and is non-standard on Apple
if test x"$BASH" = x"/bin/sh" && test -z "$UPCXX_REEXEC$UPCXX_REEXEC_SILENT" ; then
  if test -x /bin/bash ; then
    exec env UPCXX_REEXEC_SILENT=1 /bin/bash "$0" "$@"
  fi
  # on exec failure, try again in PATH
  exec env UPCXX_REEXEC=1 bash "$0" "$@"
fi

# Minimum we support is 3.2.57
UPCXX_BASH_MAJ=3
UPCXX_BASH_MIN=2
UPCXX_BASH_PATCH=57
UPCXX_BASH_FLOOR="$UPCXX_BASH_MAJ.$UPCXX_BASH_MIN.$UPCXX_BASH_PATCH"

bad_shell() {
  echo "ERROR: UPC++ requires bash version $UPCXX_BASH_FLOOR or newer, please re-run" >&2
  echo "ERROR: using '/full/path/to/suitable/bash $0 [args]'" >&2
  echo "ERROR: $*" >&2
  exit 1
}

# Either could not exec bash in $PATH or we did and it is not bash
if test -z "$BASH_VERSION" || test -z "$BASH"; then
  bad_shell 'bash was not found in $PATH, or does not appear to be bash.'
fi

##
## End portable (no bash-isms) logic.
## We may now assume we are running bash
##

## Versioning scheme changed between 2 and 3, but has been stable since
if (( BASH_VERSINFO[0] < 3 )) ||
   (( 10000*BASH_VERSINFO[0] + 100*BASH_VERSINFO[1] + BASH_VERSINFO[2] <
      10000*UPCXX_BASH_MAJ   + 100*UPCXX_BASH_MIN   + UPCXX_BASH_PATCH )); then
  bad_shell "This bash reports a version of '$BASH_VERSION'."
fi
set +o posix

# Record the full command line (with shell quoting, suitable for reexecution).
# The value has ": " prefixed, but rather than trim that off, we encorporate
# it into the final output.
fullcmd=$(set -- "$0" "$@"; PS4=; exec 2>&1; set -x; : "$@")

# Preserve command and all output for post mortem
if [[ -z "$UPCXX_CONFIGURE_TEED" ]]; then
  echo "UPC++ configure$fullcmd" >| config.log
  exec &> >(tee -a config.log)
  UPCXX_CONFIGURE_TEED=y exec $BASH "$0" "$@"
fi

#
# Usage
#

function usage {
  cat <<'EOF'
Usage:
  --prefix=...
        Specifies the installation directory.
        The default is '/usr/local/upcxx'.

  --with-cc=...
  --with-cxx=...
        Specify the C and C++ compilers to use.
        Override the values of $CC and $CXX, if any.
        The (platform dependent) default is usually appropriate.
  --enable-allow-mismatched-compilers
  --disable-allow-mismatched-compilers
        Controls compiler version sanity checking
        By default, this configure script rejects use of CXX and CC which do
        not appear to be from the same release.  The enable form of this option
        converts this behavior to a warning, while the disable form restores
        the default (error) behavior.
  --with-cross(=...)
  --without-cross
        Control cross-compilation.
        Passing `--with-cross` (without a value) requests the default
        auto-detection behavior, while providing a value requests a
        specific cross-compilation target.
        Passing `--without-cross` disables cross-compilation.
        Overrides the value of $UPCXX_CROSS, if any.
        The default behavior (auto-detection) is appropriate unless
        auto-detection is making the wrong choice.

  --enable-cuda
  --disable-cuda
        Enabled or disable UPC++ Memory Kinds over NVIDIA CUDA.
        Overrides the value of $UPCXX_CUDA, if any.
  --with-nvcc=...
        Overrides the value of $UPCXX_CUDA_NVCC, if any.
        The default is to search for 'nvcc' in $PATH.
  --with-cuda-cppflags=...
        Sets the pre-processor flags needed to find CUDA runtime headers.
        Overrides the value of $UPCXX_CUDA_CPPFLAGS, if any.
        The default is to probe 'nvcc'.
  --with-cuda-libflags=...
        Sets the linker flags needed to link CUDA runtime libraries.
        Overrides the value of $UPCXX_CUDA_LIBFLAGS, if any.
        The default is to probe 'nvcc'.

  --enable-hip
  --disable-hip
        Enable or disable UPC++ Memory Kinds over AMD ROCm/HIP.
  --with-hip-home=...
        Install prefix of HIP developer tools 
        The default is determined by searching for 'hipcc' in $PATH.
  --with-hip-cppflags=...
        Sets the pre-processor flags needed to find HIP runtime headers.
        Overrides the value of $UPCXX_HIP_CPPFLAGS, if any.
        The default is automatically determined based on the host compiler.
  --with-hip-libflags=...
        Sets the linker flags needed to link HIP runtime libraries.
        Overrides the value of $UPCXX_HIP_LIBFLAGS, if any.
        The default is automatically determined.
  --with-hip-platform=nvidia
        Activates EXPERIMENTAL support for --enable-hip using HIP-over-CUDA on NVIDIA GPUs.
        Additionally requires a working CUDA installation (details in INSTALL.md).
        The default of --with-hip-platform=amd selects AMD-branded GPU hardware.

  --enable-ze
  --disable-ze
        Enable or disable UPC++ Memory Kinds over Intel Level Zero.
  --with-ze-home=...
        Install prefix of Level Zero developer tools 
        The default is determined by searching for 'ocloc' in $PATH.
  --with-ze-cppflags=...
        Sets the pre-processor flags needed to find Level Zero runtime headers.
        Overrides the value of $UPCXX_ZE_CPPFLAGS, if any.
        The default is automatically determined.
  --with-ze-libflags=...
        Sets the linker flags needed to link ze runtime libraries.
        Overrides the value of $UPCXX_ZE_LIBFLAGS, if any.
        The default is automatically determined.

  --enable-ccs-rpc
  --disable-ccs-rpc
        Enable or disable support for Cross Code Segment (CCS) RPC and
        CCS error detection.

  --with-default-network=...
        Specifies the default network.
        The default is system dependent.

  --with-gasnet=...
        Specifies the URL or path of GASNet sources.
        Overrides the value of $GASNET, if any.
        The default is normally sufficient.

  --with-gmake=...
        Specify the location of GNU Make 3.80 or newer.
        Overrides the value of $GMAKE, if any.
        Default is to search for 'gmake' or 'make' in $PATH.
  --with-python=...
        Specify the location of Python3 or Python2 version 2.7.5 or newer.
        Overrides the value of $UPCXX_PYTHON, if any.
        Default is to search for common Python interpreter names in $PATH
        at configure time for any meeting the version requirement.  The first
        one thus identified is then located in $PATH dynamically at runtime.

  --enable-valgrind
        Enable limited support for the Valgrind dynamic analysis tool,
        at some potential cost in performance (off by default).

  --enable-discontig-ranks
        Enable support for process layouts where the rank numbering assigned
        at job spawn is permitted to be discontiguous on any given physical host.
        Otherwise, co-located ranks are required to be contiguously numbered.

  -h|--help|--usage
        Produces this message.
  --help=recursive
        Produces this message and GASNet's `configure --help` message.
  -V|--version
        Report version and copyright.

All unrecognized arguments will be passed to GASNet's configure.

Some influential environment variables:
  CXX         C++ compiler command
  CXXFLAGS    C++ compiler flags
  CXXCPP      C++ preprocessor
  CC          C compiler command
  CFLAGS      C compiler flags
  CPP         C preprocessor
  CPPFLAGS    C/C++ preprocessor flags, e.g. -I<include dir> if you have
              headers in a nonstandard directory <include dir>
  LDFLAGS     linker flags, e.g. -L<lib dir> if you have libraries in a
              nonstandard directory <lib dir>
  LIBS        libraries to pass to the linker, e.g. -l<library>
Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.

Report bugs to upcxx@googlegroups.com or at https://upcxx-bugs.lbl.gov
UPC++ home page: https://upcxx.lbl.gov

See INSTALL.md for additional information.
EOF
}

function version {
  header="$UPCXX_SRC/src/version.hpp"
  version=$(grep "# *define  *UPCXX_VERSION " ${header} 2>/dev/null| head -1)
  if [[ "$version" =~ ([0-9]{4})([0-9]{2})([0-9]{2}) ]]; then
    version="${BASH_REMATCH[1]}.${BASH_REMATCH[2]#0}.${BASH_REMATCH[3]#0}"
  else
    version=${version##*UPCXX_VERSION }
  fi
  githash=$(git describe --always 2> /dev/null)
  echo "UPC++ version $version $githash"
  echo "Copyright (c) 2025, The Regents of the University of California,"
  echo "through Lawrence Berkeley National Laboratory."
  echo "https://upcxx.lbl.gov"
  echo ""
}

#
# Global variables
#

# This script's name and location
self=$(basename $0)
UPCXX_SRC=$(cd $(dirname $(type -p $0)) && pwd -P)

# Default installation prefix
PREFIX=/usr/local/upcxx

# Init some options that are undocumented and/or have no documented envvar switch
single=''
hip_platform=''

# Text to emit at end
# Each distinct warning added should start with a newline
warnings=''

# backwards compat: CROSS
# must preserve both unset and set-but-empty, which have significance
if [[ ${UPCXX_CROSS-unset}${CROSS+set} == 'unsetset' ]]; then
  export UPCXX_CROSS=${CROSS}
fi

# Preserve env vars which options processing may clobber
UPCXX_CONFIG_ENVVARS=( CC CFLAGS CXX CXXFLAGS CPPFLAGS LDFLAGS LIBS\
                       GASNET GASNET_CONDUIT GASNET_CONFIGURE_ARGS UPCXX_CROSS \
                       GMAKE UPCXX_PYTHON \
                       UPCXX_CUDA{,_NVCC,_CPPFLAGS,_LIBFLAGS} \
                       HIP_HOME UPCXX_HIP{,_CPPFLAGS,_LIBFLAGS} \
                       ZE_HOME UPCXX_ZE{,_CPPFLAGS,_LIBFLAGS} )
for var in ${UPCXX_CONFIG_ENVVARS[*]} ; do
    eval ORIG_$var=\'${!var}\'
done

# Clear "new" non-legacy configure options
# these are only accepted on the configure line and not via environment
UPCXX_VALGRIND=
UPCXX_DISCONTIG=
UPCXX_FORCE_LEGACY_RELOCATIONS=''
UPCXX_HAVE_OPENMP=
UPCXX_HAVE_CXX17=

unset gasnet_help

#
# Error handling
#

function echo_and_die {
  echo $* >&2
  exit 1
}

function failure_and_die {
  echo "UPC++ configuration failed. Please report the entire log above to: upcxx@googlegroups.com" >&2
  exit 1
}

function get_arg_val {
  if [[ "$*" =~ (^[^=]*=(.+)) ]]; then
    echo "${BASH_REMATCH[2]}"
  else
    echo "ERROR: option '${1%=}' is missing its required value." >&2
    echo "Run '$0 --help' for complete usage information." >&2
    exit 1
  fi
}

#
# Argument parsing
#

shopt -s extglob
trap exit ERR  # so exit in get_arg_val exits from top-level
# DO NOT simplify 'FOO="$(get_arg_val $1)"; export FOO;' to a single command, or get_arg_val can't fatal-exit
while [[ $# -gt 0 ]]; do
  arg="$1"
  orig_arg="$1"
  shift
  # uniform preprocessing on args:
  if [[ "$arg" =~ (^-+(.+)) ]]; then # normalize to single dash
    arg="-${BASH_REMATCH[2]}"
  fi
  if [[ "$arg" =~ (^-+enable-(.+)) ]]; then  # -enable  => -with
    arg="-with-${BASH_REMATCH[2]}"
  fi
  if [[ "$arg" =~ (^-+disable-(.+)) ]]; then # -disable => -without
    arg="-without-${BASH_REMATCH[2]}"
  fi
  #echo "configure: arg '$orig_arg' => '$arg'"
  case "$arg" in
    # Passed explicitly to GASNet's configure:
    -prefix?(=*))               PREFIX="$(get_arg_val $arg)";;

    # Used to find and run GASNet's configure:
    -with-gasnet?(=*))          GASNET="$(get_arg_val $arg)";         export GASNET;;
    -with-cross)                unset UPCXX_CROSS;                  export UPCXX_CROSS;;
    -with-cross?(=*))           UPCXX_CROSS="$(get_arg_val $arg)";    export UPCXX_CROSS;;
    -without-cross)             UPCXX_CROSS='';                     export UPCXX_CROSS;;

    # Not relevant to GASNet's configure:
    -with-default-network?(=*)) GASNET_CONDUIT="$(get_arg_val $arg)"; export GASNET_CONDUIT;;
    -with-python?(=*))          UPCXX_PYTHON="$(get_arg_val $arg)"; export UPCXX_PYTHON;;
    -without-discontig-ranks)   UPCXX_DISCONTIG=''; export UPCXX_DISCONTIG;;
    -with-discontig-ranks)      UPCXX_DISCONTIG=1; export UPCXX_DISCONTIG
      warnings+="\nWARNING: --enable-discontig-ranks mode activated.\n"
      warnings+='WARNING: This mode has not been carefully tuned and is not recommended for general use.\n'
      warnings+='WARNING: If this feature matters to you, please let us know!\n'
      ;;
    -with-allow-compiler-mismatch)    UPCXX_ALLOW_COMPILER_MISMATCH=1;;
    -without-allow-compiler-mismatch) UPCXX_ALLOW_COMPILER_MISMATCH=0;;

    # Passed explicitly to GASNet's configure, potentially after some processing:
    -with-cc?(=*))              CC="$(get_arg_val $arg)";    export CC;;
    -with-cxx?(=*))             CXX="$(get_arg_val $arg)";   export CXX;;
    -with-cflags?(=*))          CFLAGS="$(get_arg_val $arg)";   export CFLAGS;;  # NOT documented in usage
    -with-cxxflags?(=*))        CXXFLAGS="$(get_arg_val $arg)"; export CXXFLAGS;;# NOT documented in usage
    -with-ldflags?(=*))         LDFLAGS="$(get_arg_val $arg)"; export LDFLAGS;;  # NOT documented in usage

    # Passed to GASNet's configure implicitly via environment:
    -with-gmake?(=*))           GMAKE="$(get_arg_val $arg)"; export GMAKE;;

    # Note GASNet's related configure option(s) handled later
    -with-cuda)                 UPCXX_CUDA=1; export UPCXX_CUDA;;
    -without-cuda)              unset UPCXX_CUDA;;
    -with-nvcc?(=*))            UPCXX_CUDA_NVCC="$(get_arg_val $arg)";     export UPCXX_CUDA_NVCC;;
    -with-cuda-cppflags?(=*))   UPCXX_CUDA_CPPFLAGS="$(get_arg_val $arg)"; export UPCXX_CUDA_CPPFLAGS;;
    -with-cuda-libflags?(=*))   UPCXX_CUDA_LIBFLAGS="$(get_arg_val $arg)"; export UPCXX_CUDA_LIBFLAGS;;

    -with-hip)                 UPCXX_HIP=1; export UPCXX_HIP;;
    -without-hip)              unset UPCXX_HIP;;
    -with-hip-home?(=*))       HIP_HOME="$(get_arg_val $arg)"; export HIP_HOME;;
    -with-hip-cppflags?(=*))   UPCXX_HIP_CPPFLAGS="$(get_arg_val $arg)"; export UPCXX_HIP_CPPFLAGS;;
    -with-hip-libflags?(=*))   UPCXX_HIP_LIBFLAGS="$(get_arg_val $arg)"; export UPCXX_HIP_LIBFLAGS;;

    -with-ze)                  UPCXX_ZE=1; export UPCXX_ZE;;
    -without-ze)               unset UPCXX_ZE;;
    -with-ze-home?(=*))        ZE_HOME="$(get_arg_val $arg)"; export ZE_HOME;;
    -with-ze-cppflags?(=*))    UPCXX_ZE_CPPFLAGS="$(get_arg_val $arg)"; export UPCXX_ZE_CPPFLAGS;;
    -with-ze-libflags?(=*))    UPCXX_ZE_LIBFLAGS="$(get_arg_val $arg)"; export UPCXX_ZE_LIBFLAGS;;

    -with-ccs-rpc)              UPCXX_FORCE_LEGACY_RELOCATIONS=''; export UPCXX_FORCE_LEGACY_RELOCATIONS;;
    -without-ccs-rpc)           UPCXX_FORCE_LEGACY_RELOCATIONS=1; export UPCXX_FORCE_LEGACY_RELOCATIONS;;

    -h|-help|-usage)
      echo 'UPC++ configure script.'
      echo '======================='
      usage;
      exit 0;
      ;;

    -help=recursive)
      echo 'UPC++ configure script.'
      echo '======================='
      usage;
      echo
      echo 'GASNet-EX configure script.'
      echo '==========================='
      gasnet_help=1
      ;;

    -V|-version)
      version;
      exit 0;
      ;;

    # These are not in the usage message, but autoconf-familiar users may expect these to work:
    CC?(=*))   CC="$(get_arg_val $arg)";    export CC;;
    CXX?(=*))  CXX="$(get_arg_val $arg)";   export CXX;;
    CFLAGS?(=*))   CFLAGS="$(get_arg_val $arg)";    export CFLAGS;;
    CXXFLAGS?(=*)) CXXFLAGS="$(get_arg_val $arg)";  export CXXFLAGS;;
    LDFLAGS?(=*)) LDFLAGS="$(get_arg_val $arg)";    export LDFLAGS;;

    # These are to remain undocumented
    -v|-verbose) set -x ;;
    -with-single?(=*))
      single="$(get_arg_val $arg)"
      warnings+="\nWARNING: --enable-single=$single mode enabled.\n"
      warnings+='WARNING: This mode is intended for maintainers only.\n'
      warnings+='WARNING: Many make targets will fail and components will be missing.\n'
      ;;
    -with-mpsc-queue=*)
      UPCXX_MPSC_QUEUE="$(get_arg_val $arg)"; export UPCXX_MPSC_QUEUE
      ;;
    # deliberately undocumented maintainer flags to control default dev-test set
    -with-tests-cxx17)     UPCXX_HAVE_CXX17=1  ; export UPCXX_HAVE_CXX17 ;;
    -without-tests-cxx17)  UPCXX_HAVE_CXX17=   ; export UPCXX_HAVE_CXX17 ;;
    -with-tests-openmp)    UPCXX_HAVE_OPENMP=1 ; export UPCXX_HAVE_OPENMP ;;
    -without-tests-openmp) UPCXX_HAVE_OPENMP=  ; export UPCXX_HAVE_OPENMP ;;

    *) # Anything we don't consume above will be passed to GASNet's configure

      case "$arg" in 

        # These options are interpreted here and ALSO passed to GASNet's configure
        -with-valgrind)     UPCXX_VALGRIND=1 ; export UPCXX_VALGRIND;;
        -without-valgrind)  UPCXX_VALGRIND=  ; export UPCXX_VALGRIND;;

        # Deliberately Undocumented
        -with-hip-platform?(=*))       hip_platform="$(get_arg_val $arg)";
      
      esac


      # Quoting is believed sufficient for space, tab, single-quote and double-quote.
      # We pass the unmodified argument to GASNet configure
      GASNET_CONFIGURE_ARGS+="${GASNET_CONFIGURE_ARGS+ }\"${orig_arg//\"/\\\"}\""
      ;;
  esac
done  

trap failure_and_die ERR  # errors after arg parsing are fatal

#
# Helper functions
#

# Warn if a prog was found outside a whitelist of paths
function check_known_path {
  local exe="${1%% *}"
  case $(dirname "$exe") in
    /bin|/usr/bin|/usr/local/bin|/usr/pkg/bin|/opt/csw/bin)
      # OK
      ;;
    *)
      warnings+="${2+\nWARNING: $2\n}"
      warnings+='WARNING: This full path will be encoded in installed scripts.\n'
      warnings+='WARNING: Please ensure it is valid for all users and on all nodes.\n'
      warnings+="WARNING: Alternatively, configuring with '/usr/bin/env $(basename $exe)'\n"
      warnings+='WARNING: can be used to defer the $PATH search until run time.\n'
  esac
}

# check_tool_path()
#
# input: the path or filename to check
# accepts full paths
# searches for bare names (no /) in $PATH
# rejects relative paths and bare names not found in $PATH
# also rejects any input which is missing or not executable
# on success returns zero with absolute path on stdout
# returns non-zero on failure with (partial) error message on stdout
check_tool_path() {
  local exe="${1%% *}"
  local args="${1/$exe}"
  if [[ $exe =~ ^/ ]]; then
    # full path: check that it exists and is executable
    if [[ ! -x $exe ]]; then
      echo 'does not exist or is not executable'
      return 1
    fi
    echo "$exe$args"
  elif [[ ! $exe =~ / ]]; then
    # bare tool name: search in $PATH
    local output=$(type -p "$exe" 2>/dev/null || true)
    if [[ -z $output || ! -x $output ]]; then
      echo 'was not found in $PATH'
      return 1
    fi
    echo "$output$args"
  else
    # relative path: prohibited
    echo 'is a relative path (not permitted)'
    return 1
  fi
  return 0
}

#
# Default GASNet source
# Enable offline installers with an embedded GASNet-EX tarball
#
GASNET_DEFAULT='https://bitbucket.org/berkeleylab/gasnet/downloads/GASNet-stable.tar.gz' # Un-comment for development
#GASNET_DEFAULT='https://gasnet.lbl.gov/EX/GASNet-2025.8.0.tar.gz' # Un-comment for release
#GASNET_DEFAULT='NONE' # Un-comment for snapshots
gex_offline=`/bin/ls "$UPCXX_SRC"/src/GASNet-{stable,2???.*}.tar.gz 2> /dev/null | sort -t. -k1,1 -k2,2n -k3n | tail -1`
if [[ -n "$GASNET" ]]; then
  : # keep defn
elif [[ -r "$gex_offline" ]]; then
  GASNET="$gex_offline"
elif [[ $GASNET_DEFAULT == 'NONE' ]]; then
  echo_and_die 'There is no GASNet tarball available for this UPC++ version. Please obtain a tarball of this UPC++ version containing an embedded GASNet archive.'
else
  GASNET=$GASNET_DEFAULT
fi

#
# Fetch and unpack GASNet (as required) and verify
#

function bad_gasnet_fetch {
  echo Error: $* >&2
  echo_and_die "Please correct the URL or point --with-gasnet=... at a manually downloaded GASNet source .tar.gz file ($GASNET_DEFAULT is the recommended version)"
}
ORIG_GASNET="$GASNET"
GASNET_UNPACKED=""
GASNET_TYPE=source  # default
if [[ -n "$single" && -r "$GASNET/gasnet_config.h" ]] ; then
  # single + GASNET=builddir (may or may not be a srcdir as well)
  GASNET_TYPE=build
  # Convert relative path of build directory to absolute if necessary
  if ! expr "/$GASNET" : // >/dev/null; then
    export GASNET=$(cd "$GASNET" && pwd -P)
  fi
elif [ -r "$GASNET/gasnet_config.h.in" ]; then
  # Convert relative path of souce directory to absolute if necessary
  if ! expr "/$GASNET" : // >/dev/null; then
    export GASNET=$(cd "$GASNET" && pwd -P)
  fi
elif [ -r "$GASNET/gasnetex.h" ]; then
  echo_and_die "GASNET='$GASNET' appears to be an un-bootstraped source tree.  Please run '$GASNET/Bootstrap'"
elif expr "$GASNET" : '.*\.tar\.gz' >/dev/null; then
  # Unpack tarball into bld/

  # Fetch if URL, check access if PATH
  unset gex_tmp
  if [[ "$GASNET" =~ ^http ]]; then
      if [[ -n "$URL_CAT" ]] ; then
        : # keep defn
      elif [[ -n "$(type -p curl)" ]]; then
        URL_CAT='curl --retry 5 -LsSf'
      elif [[ -n "$(type -p wget)" ]]; then
        URL_CAT='wget --tries=5 -nv -O -'
      fi
      if [ -z "$URL_CAT" ]; then
        bad_gasnet_fetch "Do not know how to fetch a URL (did not find wget or curl in \$PATH)"
      fi
      gex_tmp="${GASNET##*/}"
      echo Fetching $GASNET
      eval "$URL_CAT '$GASNET' >'$gex_tmp'"
      [[ $? -eq 0 && -r "$gex_tmp" ]] || bad_gasnet_fetch "Failed to fetch '$GASNET'"
  else
      if [[ ! -r "$GASNET" ]]; then
        if [[ ! -e "$GASNET" ]]; then
          failure='does not exist'
        else
          failure='cannot be read'
        fi
        echo_and_die "GASNET='$GASNET' specifies a file which $failure. Please unset \`GASNET\` in your environment to use the default, or provide a correct value using \`--with-gasnet=...\`"
      fi
  fi

  GASNET="${gex_tmp:-$GASNET}"
  unset gex_dir
  gex_dir=$(gzip -cd "$GASNET" | tar tf - | head -1 | cut -d/ -f1)
  [[ -n $gex_dir ]] || echo_and_die "Could not read TOC from GASNET='$GASNET' (corrupted or truncated?)"
  gex_dir="$PWD/bld/$gex_dir"
  if [[ -r "$gex_dir" ]]; then
    # Sort out what to do about a conflicting destination
    if [[ -n "$gasnet_help" ]]; then
      : # leave it alone to ensure that --help=recursive is non-destructive
    elif [[ ! -r "$gex_dir/gasnet_config.h.in" ]]; then
      # Does not appear to be from a GASNet-EX tarball - give up rather than clobber
      echo_and_die "Refusing to remove '$gex_dir', which does not appear to be a bootstrapped GASNet-EX source directory.  You may need to manually rename or remove it to proceed."
    else
      rm -Rf "$gex_dir"
    fi
  fi

  if [[ ! -r "$gex_dir" ]]; then
    trap - ERR # suspend error handler for detailed diagnostics
    mkdir -p bld
    echo Unpacking $GASNET
    gzip -cd "$GASNET" | ( cd bld && tar xf - )
    rc1=${PIPESTATUS[0]} rc2=${PIPESTATUS[1]}
    [ $rc1 -eq 0 ] || echo_and_die "Failed to gunzip '$GASNET' (corrupted or truncated?)"
    [ $rc2 -eq 0 ] || echo_and_die "Failed to untar '$GASNET' (corrupted or truncated?)"
    [ -r "$gex_dir/gasnet.h" ] || echo_and_die "GASNET='$ORIG_GASNET' does not appear to contain GASNet"
    if [[ ! -r "$gex_dir/version.git" && -n $(type -p git) ]]; then
      # Attempt to fill a missing version.git using commit id, if available
      gex_hash=$(gzip -cd "$GASNET" | git get-tar-commit-id 2> /dev/null || echo INVALID)
      [[ $gex_hash =~ (^[0-9a-fA-F]{40}$) ]] && echo "gex-archive-g${gex_hash:0:8}" > "$gex_dir/version.git"
    fi
    trap failure_and_die ERR  # restore error handler
    [ -n "$gex_tmp" ] && rm -f "$gex_tmp"
    GASNET_UNPACKED=$gex_dir
    echo
  fi
  export GASNET="$gex_dir"
else
  echo_and_die "GASNET='$GASNET' is not a valid value.  GASNET must name local tarball file, tarball url, or gasnet source tree.  Please unset \`GASNET\` in your environment to use the default, or provide a correct value using \`--with-gasnet=...\`"
fi

if [[ "$GASNET_TYPE" == 'build' ]]; then
  if [ -e "$GASNET/configure" ] ; then
    gex_header="$GASNET/gasnetex.h"
  else
    gex_header=''  # TODO: any non G-1 file to check in a VPATH build directory?
  fi
  gex_spec_file="$GASNET/gasnet_config.h"
else
  gex_header="$GASNET/gasnetex.h"
  gex_spec_file="$GASNET/docs/GASNet-EX.txt"
fi

# verify distinguishing file (if any)
[[ -z "$gex_header" || -r "$gex_header" ]] || \
    echo_and_die "GASNET='$ORIG_GASNET' does not contain GASNet-EX (GASNet-1 or GASNet_Tools?)"

# verify minimum version
[[ $(grep 'EX_SPEC_VERSION_MAJOR' "$gex_spec_file" | head -1 | tr '\t' ' ') =~ ( ([0-9]+)) ]]
HAVE_MAJ=${BASH_REMATCH[2]}
[[ $(grep 'EX_SPEC_VERSION_MINOR' "$gex_spec_file" | head -1 | tr '\t' ' ') =~ ( ([0-9]+)) ]]
HAVE_MIN=${BASH_REMATCH[2]}
upcxx_header="$UPCXX_SRC/src/backend/gasnet/runtime_internal.hpp"
[[ $(grep 'UPCXXI_REQUIRES_GEX_SPEC_VERSION_MAJOR.*' "$upcxx_header" | head -1 | tr '\t' ' ') =~ ( ([0-9]+)) ]]
WANT_MAJ=${BASH_REMATCH[2]}
[[ $(grep 'UPCXXI_REQUIRES_GEX_SPEC_VERSION_MINOR.*' "$upcxx_header" | head -1 | tr '\t' ' ') =~ ( ([0-9]+)) ]]
WANT_MIN=${BASH_REMATCH[2]}
[[ ($HAVE_MAJ -gt $WANT_MAJ) || (($HAVE_MAJ -eq $WANT_MAJ) && ($HAVE_MIN -ge $WANT_MIN)) ]] || \
    echo_and_die "GASNET='$ORIG_GASNET' does not contain GASNet-EX implementing specification version $WANT_MAJ.$WANT_MIN or newer"

#
# Bootstrap GASNet-EX sources, if needed
#
if [[ "$GASNET_TYPE" == 'source' && ! -r "$GASNET/gasnet_config.h.in" ]]; then
  echo 'Bootstrapping GASNet-EX sources (please be patient)'
  rm -f bootstrap.log
  $GASNET/Bootstrap &> bootstrap.log || \
    echo_and_die "GASNET='$ORIG_GASNET' appears to contain an un-bootstraped source tree and an attempt to bootstrap the sources has failed.  This most often occurs when 'autoconf' or 'automake' are not available.  Please see 'bootstrap.log' for the output of the failed GASNet-EX bootstrap."
  rm -f bootstrap.log
  echo
fi

#
# GASNet's help message if requested
#
if [[ -n "$gasnet_help" ]]; then
  exec $GASNET/configure --help
  echo "Failed to run GASNet's configure --help"
  exit 1
fi

#
# Canonicalize $PREFIX
#

# Form a "textually canonical" path.
#
# + Result is a full path without any extraneous / or .
#
# + The input path can be relative or absolute
# + White space in path is safe and is preserved
# + The input path does not need to exist (and is not created)
#
# + Does NOT verify elems are dirs (so /etc/passwd/foo is acceptable)
# + Does NOT resolve symlinks
#
function canon_path() {
  local path="$1"

  # Make absolute if relative
  [[ "$path" =~ (^/) ]] || path="$PWD/$path"

  # Ensure trailing '/.' and '/..' are not special cases
  path="$path/"

  # Convert '//' and '/./' to '/'
  while true; do
    local tmp=$(sed -e 's|//*|/|g' -e 's|/\./|/|g' <<<"$path")
    [[ "$tmp" = "$path" ]] && break
    path="$tmp"
  done

  # Remove all 'dir/../'
  while true; do
    local tmp=$(sed -e 's|[^/][^/]*/\.\./||g' <<<"$path")
    [[ "$tmp" = "$path" ]] && break
    path="$tmp"
  done

  # Convert any leading '/../' to '/'
  while true; do
    local tmp=$(sed -e 's|^/\.\./|/|g' <<<"$path")
    [[ "$tmp" = "$path" ]] && break
    path="$tmp"
  done

  path="${path/%\//}" # removes the trailing /

  if [[ -n "$path" ]]; then echo "$path"; else echo '/'; fi
}
PREFIX=$(canon_path "$PREFIX")

#
# --enable-single={opt,debug}
#
case $single in
  '')
    UPCXX_DBGOPT='debug opt'
    ;;
  opt|debug)
    UPCXX_DBGOPT=$single
    ;;
  *)
    echo_and_die "ERROR: --enable-single='$single' is not a valid option"
    ;;
esac

#
# Default UPCXX_MPSC_QUEUE
#
if [[ -z "$UPCXX_MPSC_QUEUE" ]] ; then
  UPCXX_MPSC_QUEUE=atomic
else
  case "$UPCXX_MPSC_QUEUE" in
    atomic|biglock)
      ;; # OK
    *)
      echo "ERROR: UPCXX_MPSC_QUEUE='$UPCXX_MPSC_QUEUE' is not a valid value."
      echo_and_die 'See docs/maintainer.md for valid values and additional info.'
      ;;
  esac
fi

#
# Cross-compilation
#
if [[ ${UPCXX_CROSS-unset} == 'unset' ]]; then
    : # attempt to auto-detect from environment if/when possible
else
    case $UPCXX_CROSS in
      '')
        # disabled: nothing to do
        ;;
      *)
        # explicit but unknown
        warnings+="\nWARNING: Unrecognized (thus unsupported) cross-compilation target '$UPCXX_CROSS'\n"
        ;;
    esac
fi
export UPCXX_CROSS

#
# system-checks
#
. $UPCXX_SRC/utils/system-checks.sh
sys_info
platform_sanity_checks
platform_settings

#
# Ensure Makefile captures any env vars that platform_sanity_checks may have set/modified
#
export CC
export CXX
# Quoting is believed sufficient for space, tab, single-quote and double-quote.
# Do not make these conditional on non-empty values.  We want to preserve empty values too.
GASNET_CONFIGURE_ARGS+=" --with-cc=\"${CC//\"/\\\"}\""
GASNET_CONFIGURE_ARGS+=" --with-cflags=\"${CFLAGS//\"/\\\"}\""
GASNET_CONFIGURE_ARGS+=" --with-cxx=\"${CXX//\"/\\\"}\""
GASNET_CONFIGURE_ARGS+=" --with-cxxflags=\"${CXXFLAGS//\"/\\\"}\""
GASNET_CONFIGURE_ARGS+=" --with-ldflags=\"${LDFLAGS//\"/\\\"}\""

#
# Colorization support
# Use of __INTEL_POST_CFLAGS is an ugly hack to convert a specific warning to an error
# TODO: better soln for Intel?
#
color_opts=( '-fdiagnostics-color=always' )
echo 'int main() { return 0; }' >| conftest.c
UPCXX_COLOR_CFLAGS=''
for opt in "${color_opts[@]}"; do
  if __INTEL_POST_CFLAGS+=' -we10148' $CC -c $opt -o conftest.o conftest.c >& /dev/null; then
    UPCXX_COLOR_CFLAGS="$opt"
    break
  fi
done
echo 'int main() { return 0; }' >| conftest.cpp
UPCXX_COLOR_CXXFLAGS=''
for opt in "${color_opts[@]}"; do
  if __INTEL_POST_CFLAGS+=' -we10148' $CXX -c $opt -o conftest.o conftest.cpp >& /dev/null; then
    UPCXX_COLOR_CXXFLAGS="$opt"
    break
  fi
done
rm -f conftest.cpp conftest.c conftest.o

#
# UPCXX_PYTHON
# First expand full path or validating existence
# Second check version
#
UPCXX_PYTHON_MIN=2.7.5
function check_py {
  "$@" -c "import sys; sys.exit(sys.version_info < (${UPCXX_PYTHON_MIN//./,}));" &> /dev/null;
}
unset py fpy # given/guessed value and its full path
if [[ -n $UPCXX_PYTHON ]]; then
  py="$UPCXX_PYTHON"
  fpy=$(check_tool_path "$UPCXX_PYTHON") && :  # "&& :" prevents ERR trap but preserves $?
  if [[ $? -ne 0 ]]; then
    echo "ERROR: Python interpreter '$UPCXX_PYTHON' $fpy." >&2
    echo_and_die "Use '--with-python=...' to specify a different Python interpreter."
  elif [[ $UPCXX_PYTHON =~ ^/ ]]; then
    python_whence='specified by full path'
  else
    python_whence='found in $PATH'
  fi
  fpy_ver="$($fpy --version 2>&1)" && :
  if [[ $? -ne 0 ]]; then
    echo_and_die "ERROR: Requested python interpreter failed running '$UPCXX_PYTHON --version'"
  fi
  if ! check_py $fpy &> /dev/null; then
    echo "ERROR: Requested python interpreter '$UPCXX_PYTHON' reports version '$fpy_ver'" >&2
    echo_and_die "ERROR: Python interpreter is older than the minimum of $UPCXX_PYTHON_MIN."
  fi
else
  for py in python python3 python3.{0..20} python2; do
    tmp=$(type -p "$py" 2>/dev/null || true)
    if [[ -n $tmp && -x $tmp ]] && check_py $tmp; then
      fpy="$tmp"
      break
    fi
  done
  if [[ -z "$fpy" ]]; then
    echo 'ERROR: No suitable Python interpreter was found in $PATH'
    echo_and_die "Use '--with-python=...' to specify a Python interpreter ($UPCXX_PYTHON_MIN or newer)."
  fi
  python_whence='found in $PATH'
  fpy_ver="$($fpy --version 2>&1)"
fi
if test -z "$UPCXX_INSTALL_QUIET"; then
  echo "$fpy: $fpy_ver"; echo
fi
if [[ -n $UPCXX_PYTHON ]]; then
  UPCXX_PYTHON="$fpy"
  check_known_path "$fpy" "Python interpreter '$fpy' $python_whence."
else
  # If UPCXX_PYTHON unset, then preserve run-time search of $PATH
  UPCXX_PYTHON="/usr/bin/env $py"
fi

#
# Find a usable GNU Make
#
# NOTES:
# 1. The current regexp captures the patch level, but it is not yet used.
# 2. The GMAKE_NEED_{MAJ,MIN} values are also used in the generated Makefile
#    where the "logic" is more fragile than the shell logic here.
#    If the minimum is raised don't forget to update that logic too.
#
GMAKE_NEED_MAJ=3
GMAKE_NEED_MIN=80
function bad_gmake {
  echo Error: $* >&2
  echo_and_die "Please set GMAKE (or pass --with-gmake=...) to the path to GNU Make $GMAKE_NEED_MAJ.$GMAKE_NEED_MIN or newer."
}
GMAKE_SHORT="$GMAKE"
if [[ -n "$GMAKE" ]]; then
  fgm=$(check_tool_path "$GMAKE") && :  # "&& :" prevents ERR trap but preserves $?
  if [[ $? -ne 0 ]]; then
    bad_gmake "--with-gmake='$GMAKE' $fgm"
  fi
  GMAKE="$fgm"
else
  for x in gmake make; do
    tmp="$(type -p $x)" || true
    if [[ -n "$tmp" ]] ; then
      GMAKE_SHORT="$x"
      GMAKE="$tmp"
      break
    fi
  done
  if [[ -z "$GMAKE" ]] ; then
    bad_gmake "no 'gmake' or 'make' found in \$PATH."
  fi
fi
if [[ $($GMAKE --version | grep ^GNU) =~ ([0-9]+).([0-9]+)(.[0-9]+)? ]]; then
  maj=${BASH_REMATCH[1]}
  min=${BASH_REMATCH[2]}
  if [[ $maj -lt $GMAKE_NEED_MAJ ||
      ( $maj -eq $GMAKE_NEED_MAJ && $min -lt $GMAKE_NEED_MIN ) ]] ; then
    bad_gmake "'$GMAKE' is older than $GMAKE_NEED_MAJ.$GMAKE_NEED_MIN"
  fi
else
  bad_gmake "'$GMAKE' does not appear to be GNU Make"
fi
echo -e "$GMAKE\nGNU Make version ${BASH_REMATCH[0]}\n"

#
# Find a usable checksum command
# "Usable" is defined here as 32 or more alphanumerics characters
# followed by optional space
#
UPCXX_CSUMCMD=''
for cmd in shasum sha1sum md5sum md5; do
  if [[ -n $(type -p $cmd) &&
        $($cmd <<< '') =~ ^[a-zA-Z0-9]{32,}\ ? ]]; then
    UPCXX_CSUMCMD=$cmd
    break
  fi
done
if [[ -z "$UPCXX_CSUMCMD" ]]; then
  warnings+="\nWARNING: The maintainer targets 'exe' and 'run' are unavailable due to\n"
  warnings+="WARNING: lack of a usable checksum utility.\n"
fi

#
# HIP/hipcc setup
#
if [[ $UPCXX_HIP -eq 1 ]]; then
  # PREpend to allow user to disable if needed
  GASNET_CONFIGURE_ARGS="--enable-kind-hip ${GASNET_CONFIGURE_ARGS}"

  HIP_HEADER="include/hip/hip_runtime_api.h"
  hipcc="hipcc"
  if [[ -z $HIP_HOME ]] && type -p $hipcc >/dev/null ; then # try probing hipcc
    HIP_HOME="$(dirname $(dirname $(type -p $hipcc)))"
    if ! [[ -f $HIP_HOME/$HIP_HEADER ]] ; then
      for hip_maybe in \
         $($hipcc -print-rocm-search-dirs 2>&1 | grep "search path" | cut -d: -f2) ; do
         if [[ -f $hip_maybe/$HIP_HEADER ]] ; then
           HIP_HOME=$hip_maybe
           break
         fi
      done
    fi
  fi
  if [[ -z $HIP_HOME ]] && [[ -d /opt/rocm ]] ; then
    HIP_HOME=/opt/rocm # last resort, check default install dir
  fi
  if [[ -z $HIP_HOME ]] || ! [[ -f $HIP_HOME/$HIP_HEADER ]] ; then
    echo_and_die 'Failed to find ROCm/HIP developer tools, please pass --with-hip-home=/hip/install/prefix'
  else
    GASNET_CONFIGURE_ARGS+=" --with-hip-home='$HIP_HOME'"
  fi

  CXXVERS='eval $CXX --version 2>&1'
  cppflags="-I${HIP_HOME}/include"
  if [[ -z $UPCXX_HIP_CPPFLAGS ]]; then
    if $CXXVERS | grep -e 'Free Software Foundation' -e 'clang version' &> /dev/null ; then
      # -isystem silences obnoxious warnings from ROCm headers that are not pedantic-clean
      # but `-isystem /usr/include` can break `#include_next` (issue 630)
      [[ "${HIP_HOME}" = '/usr' ]] || cppflags+=" -isystem ${HIP_HOME}/include"
    fi
  fi
  case ${hip_platform} in
    amd|hcc|'')
      cpp_defined CXX __HIP_PLATFORM_AMD__ || UPCXX_HIP_CPPFLAGS+=' -D__HIP_PLATFORM_AMD__='
      cpp_defined CXX __HIP_PLATFORM_HCC__ || UPCXX_HIP_CPPFLAGS+=' -D__HIP_PLATFORM_HCC__='
      export UPCXX_HIP_LIBFLAGS=${UPCXX_HIP_LIBFLAGS:--L${HIP_HOME}/lib -lamdhip64}
      ;;
    nvidia|nvcc)
      if [[ -z $UPCXX_HIP_CPPFLAGS ]]; then
        if $CXXVERS | grep -e 'Free Software Foundation' -e 'clang version' &> /dev/null ; then
          # disable warnings generated by HIP-over-CUDA header: (TODO: icpc needs -wd1478 -wd303)
          cppflags+=" -Wno-deprecated-declarations -Wno-return-type"
        fi
      fi
      cpp_defined CXX __HIP_PLATFORM_NVIDIA__ || UPCXX_HIP_CPPFLAGS+=' -D__HIP_PLATFORM_NVIDIA__='
      cpp_defined CXX __HIP_PLATFORM_NVCC__   || UPCXX_HIP_CPPFLAGS+=' -D__HIP_PLATFORM_NVCC__='
      export UPCXX_HIP_LIBFLAGS=${UPCXX_HIP_LIBFLAGS:--L${HIP_HOME}/lib -lcudart}
      UPCXX_CUDA=1 # force enable full CUDA support for simplicity
      ;;
    *)
      echo_and_die 'unrecognized argument to --with-hip-platform={amd,nvidia}'
      ;;
  esac
  UPCXX_HIP_CPPFLAGS="${cppflags} ${UPCXX_HIP_CPPFLAGS}"
  [[ -z ${HIP_LIBS} ]] && HIP_LIBS=${UPCXX_HIP_LIBFLAGS}
fi

#
# ZE setup
#
if [[ $UPCXX_ZE -eq 1 ]]; then
  # PREpend to allow user to disable if needed
  # Do not enable until accelerated ZE kind support in GASNet-EX reaches production-quality
  #GASNET_CONFIGURE_ARGS="--enable-kind-ze ${GASNET_CONFIGURE_ARGS}"

  ZE_HEADER="include/level_zero/ze_api.h"
  zecmd="ocloc"
  if [[ -z $ZE_HOME ]] && type -p $zecmd >/dev/null ; then # try probing zecmd
    ZE_HOME="$(dirname $(dirname $(type -p $zecmd)))"
  fi
  if [[ -z $ZE_HOME ]] && [[ -d /usr/include ]] ; then
    ZE_HOME=/usr # last resort, check system include dir
  fi
  if [[ -z $ZE_HOME ]] || ! [[ -f $ZE_HOME/$ZE_HEADER ]] ; then
    echo_and_die 'Failed to find Intel Level Zero developer tools, please pass --with-ze-home=/ze/install/prefix'
  else
    GASNET_CONFIGURE_ARGS+=" --with-ze-home='$ZE_HOME'"
  fi
  if [[ -z ${UPCXX_ZE_LIBFLAGS} ]] ; then
    ZE_LIB=ze_loader
    for dir in lib lib64 lib/x86_64-linux-gnu ; do # TODO: improve this search
      if [[ -f $ZE_HOME/$dir/lib${ZE_LIB}.so || -f $ZE_HOME/$dir/lib${ZE_LIB}.a ]] ; then
        UPCXX_ZE_LIBFLAGS="-L${ZE_HOME}/$dir -l$ZE_LIB"
      fi
    done
    if [[ -z ${UPCXX_ZE_LIBFLAGS} ]] ; then
      echo_and_die 'Failed to find Intel Level Zero library, please pass --with-ze-libflags="-L/ze/install/prefix/lib -l'$ZE_LIB'"'
    fi
  fi

  [[ -z ${UPCXX_ZE_CPPFLAGS} ]] && UPCXX_ZE_CPPFLAGS="-I${ZE_HOME}/include"
  [[ -z ${ZE_LIBS} ]] && ZE_LIBS=${UPCXX_ZE_LIBFLAGS}
fi

#
# CUDA/nvcc setup
# TODO: error reporting could be improved substantially.
# In particular, we discard much of the failure output from nvcc
#
if [[ $UPCXX_CUDA -eq 1 ]]; then
  # PREpend to allow user to disable if needed
  GASNET_CONFIGURE_ARGS="--enable-kind-cuda-uva ${GASNET_CONFIGURE_ARGS}"
  trap - ERR # suspend error handler
  # UPCXX_CUDA_NVCC: the nvcc utility
  nvcc=$(check_tool_path "${UPCXX_CUDA_NVCC:-nvcc}")
  if [[ $? -ne 0 ]]; then
    if [[ -z "$UPCXX_CUDA_NVCC" ]]; then
      echo_and_die 'ERROR: $UPCXX_CUDA_NVCC unset and 'nvcc' not found in $PATH'
    else
      echo_and_die "ERROR: --with-nvcc='$UPCXX_CUDA_NVCC' $nvcc"
    fi
  fi
  echo "${nvcc}:"
  $nvcc --version
  if [[ $? -ne 0 ]]; then
    echo_and_die "failed to run '$nvcc --version'"
  fi
  echo
  UPCXX_CUDA_NVCC="$nvcc"

  unset cxx_is_nvcc
  if $CXX --version 2>&1 | grep 'Cuda compiler driver' &> /dev/null; then
    cxx_is_nvcc=1
  fi

  # UPCXX_CUDA_CPPFLAGS: pre-processor flags
  if [[ ${UPCXX_CUDA_CPPFLAGS+set} ]]; then
    : # Keep existing value
  elif [[ $cxx_is_nvcc ]]; then
    UPCXX_CUDA_CPPFLAGS=''
  else
    # We run a subprocess w/ output to fd 3, and append $? (w/o trailing newline) to this fd
    # Bash "read" will yield non-zero due to lack of newline, which we use to capture $rc
    # Inspired by
    #    https://stackoverflow.com/questions/16854280
    #    https://stackoverflow.com/questions/43736021
    cppflags=''
    exec 3< <( $nvcc --dryrun -c foo.cpp -o foo.o 2>&1 ; echo -n $?)
    while IFS= read -u 3 -r line || { rc=$line && break; }; do
      if [[ "$line" =~ (^#\$ INCLUDES=(.*)) ]]; then
        set -- ${BASH_REMATCH[2]}
        for flag in "$@"; do
          [[ "$flag" =~ ^\" ]] && flag="${flag:1:${#flag}-2}"
          if [[ "$flag" =~ ^-[ID] ]]; then
            cppflags+=" $flag"
          fi
        done
      fi
    done
    [[ $rc -ne 0 ]] && echo_and_die "failed to run $nvcc (error code $rc) to extract pre-process flags"
    UPCXX_CUDA_CPPFLAGS=${cppflags# } # strip leading ' ' resulting from simple x+=" $y"
  fi

  # UPCXX_CUDA_LIBFLAGS: linker flags
  if [[ ${UPCXX_CUDA_LIBFLAGS+set} ]]; then
    : # Keep existing value
  elif [[ $cxx_is_nvcc ]]; then
    UPCXX_CUDA_LIBFLAGS='-lcuda'
  else
    libflags=''
    # Use incantation similar to one above to yield rc and last line output
    exec 3< <( $nvcc --dryrun foo.o 2>&1 ; echo -n $?)
    while IFS= read -u 3 -r line || { rc=$line && break; }; do last=$line; done
    [[ $rc -ne 0 ]] && echo_and_die "failed to run $nvcc (error code $rc) to extract link flags"
    set -- $last
    # Make a pass to remove object files and strip quotes
    for ((i = 1 ; i <= $# ; i++)); do
      flag="${@:i:1}"
      if [[ "$flag" =~ .*\.o\"?$ ]]; then
        # drop object files
        set -- "${@:1:i-1}" "${@:i+1}"
        i=$((i-1))
      elif [[ "$flag" =~ ^\"(.*)\"$ ]]; then
        # strip quotes
        set -- "${@:1:i-1}" "${BASH_REMATCH[1]}" "${@:i+1}"
      fi
    done
    # Second pass actually parses
    for ((i = 1 ; i <= $# ; i++)); do
      flag="${@:i:1}"
      case $flag in
        -L*|-l*|-Wl,*|-pthread)
          # Capture this flag
          libflags+=" $flag"
          ;;
        -Xlinker|-rpath)
          # Capture this flag and its argument
          i=$((i+1))
          libflags+=" $flag ${@:i:1}"
          ;;
        -Wl,--start-group)
          # Capture the entire group including its delimiters
          for ((j = i ; j <= $# ; j++)); do
            flag="${@:j:1}"
            libflags+=" $flag"
            [[ "$flag" == '-Wl,--end-group' ]] && break
          done
          ;;
      esac
    done
    UPCXX_CUDA_LIBFLAGS=${libflags# } # strip leading ' ' resulting from simple x+=" $y"
  fi

  # check that the CUDA Driver API is linkable, adding explicit link flags if needed
  DETAIL_LOG=config-cuda.log
  rm -f $DETAIL_LOG
  echo -e "#include <cuda.h>\n#include <cuda_runtime_api.h>\nint main() { cuInit(0); return 0; }" >| conftest.cpp
  for ldextra in '' '-lcuda' '-framework CUDA' 'FAIL'; do
    cmd="$CXX $UPCXX_CUDA_CPPFLAGS $LDFLAGS conftest.cpp -o conftest.exe $UPCXX_CUDA_LIBFLAGS $ldextra"
    echo '$' $cmd >> $DETAIL_LOG
    eval $cmd >> $DETAIL_LOG 2>&1
    if [[ $? -eq 0 ]]; then
      echo '$ ./conftest.exe' >> $DETAIL_LOG
      if ./conftest.exe >> $DETAIL_LOG 2>&1 ; then
        [[ -n "$ldextra" ]] && UPCXX_CUDA_LIBFLAGS+=" $ldextra"
        break
      fi
    fi
  done
  rm -f conftest.cpp conftest.exe
  if [[ "$ldextra" == 'FAIL' ]]; then
    echo_and_die "failed to link against CUDA Driver API.  See $DETAIL_LOG for the link commands attempted and their output."
  fi
  rm -f $DETAIL_LOG
  unset DETAIL_LOG
  trap failure_and_die ERR  # restore error handler

  [[ -z ${CUDA_LIBS} ]] && CUDA_LIBS=${UPCXX_CUDA_LIBFLAGS}
fi

#
# Default conduit
#
ALL_CONDUITS='smp udp mpi ibv ucx ofi'
UNOFFICIAL_CONDUITS='mpi'
##
unset OFFICIAL_CONDUITS
# Set difference:
for net in $ALL_CONDUITS; do
  if [[ ! " $UNOFFICIAL_CONDUITS " =~ " $net " ]]; then
    OFFICIAL_CONDUITS+=" $net"
  fi
done
# tolower()
GASNET_CONDUIT=$(tr '[A-Z]' '[a-z]' <<<$GASNET_CONDUIT)
if [[ -z $GASNET_CONDUIT ]]; then
  if [[ $(uname -s) = 'Darwin' ]]; then
    GASNET_CONDUIT=smp
  fi
elif [[ " $UNOFFICIAL_CONDUITS " =~ " $GASNET_CONDUIT " ]]; then
  warnings+="\nWARNING: $GASNET_CONDUIT is not an officially supported network.\n"
  warnings+="Officially supported networks:$OFFICIAL_CONDUITS\n"
elif [[ " $ALL_CONDUITS " =~ " $GASNET_CONDUIT " ]]; then
  : OK
else
  echo_and_die "ERROR: --with-default-network='$GASNET_CONDUIT' is not a valid network.\nValid networks include:$OFFICIAL_CONDUITS"
fi
if [[ -n $GASNET_CONDUIT ]]; then
  # Complain if last of enabled/disable flags for the default network is disable
  if [[ $(egrep -o -e "--?(en|dis)able-$GASNET_CONDUIT([ \"]|=[^ \"]*)" <<<"$GASNET_CONFIGURE_ARGS " | tail -1) \
         =~ (--?(disable-$GASNET_CONDUIT|enable-$GASNET_CONDUIT=no)) ]]; then
    echo_and_die "ERROR: an explicit '${BASH_REMATCH[1]}' disables the default network.  Please use '--with-default-network=...' to select an alternative default network, or remove '${BASH_REMATCH[1]}'."
  fi
  # Ensure GASNet configure fails if default network is not available
  GASNET_CONFIGURE_ARGS+=" --enable-$GASNET_CONDUIT"
fi

#
# Generate bld/Makefile if needed
#
mkdir -p bld
[[ $(pwd -P) = $UPCXX_SRC ]] || echo "include $UPCXX_SRC/bld/Makefile" > "bld/Makefile"

#
# Generate top-level Makefile
#
# NOTICE: when adding variables to the Makefile that affect post-install behavior, 
# please consider if they belong in `upcxx-info` output (see `do-config-summary` target)
cat > Makefile <<EOF
# This file is generated by the UPC++ configure script
# Modifications to this file may be overwritten
#
# Configure command$fullcmd
$(: Yes, the following will break at GNU Make 10.0 or if somebody unearths a GNU Make 3.9)
ifneq (\$(firstword \$(sort \$(MAKE_VERSION) $GMAKE_NEED_MAJ.$GMAKE_NEED_MIN)), $GMAKE_NEED_MAJ.$GMAKE_NEED_MIN)
\$(error GNU Make $GMAKE_NEED_MAJ.$GMAKE_NEED_MIN or newer required, but this is \$(MAKE_VERSION))
endif
export prefix=$PREFIX
export upcxx_src=$UPCXX_SRC
export upcxx_bld=$(pwd -P)
export UPCXX_BASH=$BASH
export UPCXX_PYTHON=$UPCXX_PYTHON
export GMAKE=$GMAKE
export GMAKE_SHORT=$GMAKE_SHORT
export CONFIG_CC=$CC
export CONFIG_CXX=$CXX
export GASNET=$GASNET
export GASNET_TYPE=$GASNET_TYPE
export UPCXX_CROSS=$UPCXX_CROSS
export UPCXX_COLOR_CFLAGS=$UPCXX_COLOR_CFLAGS
export UPCXX_COLOR_CXXFLAGS=$UPCXX_COLOR_CXXFLAGS
export UPCXX_CSUMCMD=$UPCXX_CSUMCMD
export UPCXX_MPSC_QUEUE=UPCXXI_MPSC_QUEUE_$(tr '[a-z]' '[A-Z]' <<<$UPCXX_MPSC_QUEUE)
export UPCXX_DBGOPT=$UPCXX_DBGOPT
export GASNET_UNPACKED=$GASNET_UNPACKED
export GASNET_CONFIGURE_ARGS=$GASNET_CONFIGURE_ARGS
export UPCXX_CONFIGURE_NETWORK=$GASNET_CONDUIT
export UPCXX_CUDA=$UPCXX_CUDA
export UPCXX_CUDA_NVCC=$UPCXX_CUDA_NVCC
export UPCXX_CUDA_CPPFLAGS=$UPCXX_CUDA_CPPFLAGS
export UPCXX_CUDA_LIBFLAGS=$UPCXX_CUDA_LIBFLAGS
export UPCXX_HIP=$UPCXX_HIP
export UPCXX_HIP_CPPFLAGS=$UPCXX_HIP_CPPFLAGS
export UPCXX_HIP_LIBFLAGS=$UPCXX_HIP_LIBFLAGS
export UPCXX_ZE=$UPCXX_ZE
export UPCXX_ZE_CPPFLAGS=$UPCXX_ZE_CPPFLAGS
export UPCXX_ZE_LIBFLAGS=$UPCXX_ZE_LIBFLAGS
export UPCXX_VALGRIND=$UPCXX_VALGRIND
export UPCXX_DISCONTIG=$UPCXX_DISCONTIG
export UPCXX_FORCE_LEGACY_RELOCATIONS=$UPCXX_FORCE_LEGACY_RELOCATIONS
export CUDA_LIBS=$CUDA_LIBS
export HIP_LIBS=$HIP_LIBS
export ZE_LIBS=$ZE_LIBS

# These control use of optional dependencies in tests, and support command-line override:
export UPCXX_HAVE_CXX17?=$UPCXX_HAVE_CXX17
export UPCXX_HAVE_OPENMP?=$UPCXX_HAVE_OPENMP

# This does all the actual work:
include \$(upcxx_src)/bld/Makefile.rules
EOF

#
# Generate top-level bin/
#
mkdir -p bin
cat >| bin/upcxx <<EOF
#!$BASH
function die { echo -e "upcxx: ERROR: \$*" >&2; exit 1; }
vars=\$(env UPCXX_META=BUILDDIR $BASH $UPCXX_SRC/utils/upcxx.sh "\$@")
[[ \$? -ne 0 ]] && die 'pre-parse of command line failed'
if [[ \$vars =~ UPCXX_THREADMODE=([^\$IFS]*) ]]; then
  value="\${BASH_REMATCH[1]}"
  case \$value in
    seq|par) ;;
    *) die "invalid UPCXX_THREADMODE='\$value' (valid values: 'seq' or 'par')"
  esac
fi
if [[ \$vars =~ UPCXX_NETWORK=([^\$IFS]*) ]]; then
  network="\${BASH_REMATCH[1]}"
else
  network="$GASNET_CONDUIT"
fi
if [[ -n \$network && ! " $ALL_CONDUITS " =~ " \$network " ]]; then
  die "invalid UPCXX_NETWORK='\$network'.\n\$($GMAKE --no-print-directory -s -f '$PWD/Makefile' list-networks 2>&1)"
fi
vars=\${vars/UPCXX_NETWORK/GASNET_CONDUIT}
vars=\${vars/UPCXX_THREADMODE=/UPCXX_BACKEND=gasnet_}
vars=\${vars/UPCXX_CODEMODE=opt/ASSERT=0 OPTLEV=3 DBGSYM=0}
vars=\${vars/UPCXX_CODEMODE=debug/ASSERT=1 OPTLEV=0 DBGSYM=1}
[[ -z "\$UPCXX_QUIET" ]] && echo 'INFO: may need to build the required runtime.  Please be patient.' >&2
[[ -z "\$network" ]] && export GASNET_CONDUIT="\$($GMAKE --no-print-directory -s -f '$PWD/Makefile' echo-default-network)"
tmp=\$($GMAKE --no-print-directory -f '$PWD/Makefile' upcxx \$vars 2>&1)
[[ \$? -ne 0 ]] && echo "\$tmp" >&2 && die 'build of the required runtime failed.'
exec \${tmp##*\$'\n'} "\$@"
EOF
cat >| bin/upcxx-info <<EOF
#!$BASH
export UPCXX_CODEMODE=\${UPCXX_CODEMODE:=${UPCXX_DBGOPT##* }}
exec \${0%/*}/upcxx "\$@" -info
EOF
cat >| bin/upcxx-run <<EOF
#!$BASH
function die { echo -e "upcxx-run: ERROR: \$*" >&2; exit 1; }
for arg in "\$@"; do
  case \$arg in
    -h|--help) exec \${UPCXX_PYTHON-$UPCXX_PYTHON} $UPCXX_SRC/utils/upcxx-run -h ;;
    --) break ;;
  esac
done
conduit=\$(\${UPCXX_PYTHON-$UPCXX_PYTHON} $UPCXX_SRC/utils/upcxx-run -info "\$@" | grep ^GASNetConduitName: | cut -d' ' -f2 | tr '[A-Z]' '[a-z]'; exit \${PIPESTATUS[0]})
[[ \$? -ne 0 ]] && die 'pre-parse of command line failed'
codemode=\$(tr '[A-Z]' '[a-z]' <<<\${UPCXX_CODEMODE:-${UPCXX_DBGOPT% *}})
case \$codemode in
  debug)   vars='DBGSYM=1 ASSERT=1 OPTLEV=0 GASNET_CODEMODE=debug';;
  o3|opt)  vars='DBGSYM=0 ASSERT=0 OPTLEV=3 GASNET_CODEMODE=opt';;
  *) die "invalid UPCXX_CODEMODE='\$UPCXX_CODEMODE' (valid values: 'debug' or 'opt')";;
esac
[[ -z "\$UPCXX_QUIET" ]] && echo 'INFO: may need to build the required runtime.  Please be patient.' >&2
tmp=\$($GMAKE --no-print-directory -f '$PWD/Makefile' upcxx-run \$vars GASNET_CONDUIT=\$conduit 2>&1)
[[ \$? -ne 0 ]] && echo "\$tmp" >&2 && die 'build of the required runtime failed.'
exec \${tmp##*\$'\n'} "\$@"
EOF
cat >| bin/upcxx-meta <<EOF
#!$BASH
function die { echo -e "upcxx-meta: ERROR: \$*" >&2; exit 1; }
cmode=\$(tr '[A-Z]' '[a-z]' <<<\${UPCXX_CODEMODE:-opt})
case \$cmode in
  debug)   export DBGSYM=1 ASSERT=1 OPTLEV=0;;
  o3|opt)  export DBGSYM=0 ASSERT=0 OPTLEV=3;;
  *) die "invalid UPCXX_CODEMODE='\$UPCXX_CODEMODE' (valid values: 'debug' or 'opt')";;
esac
tmode=\$(tr '[A-Z]' '[a-z]' <<<\${UPCXX_THREADMODE:=seq})
case \$tmode in
  seq|par) export UPCXX_BACKEND=gasnet_\$tmode;;
  *)       die "invalid UPCXX_THREADMODE='\$UPCXX_THREADMODE' (valid values: 'seq' or 'par')";;
esac
export GASNET_CONDUIT=\$(tr '[A-Z]' '[a-z]' <<<\${UPCXX_NETWORK:-\${UPCXX_GASNET_CONDUIT:-$GASNET_CONDUIT}})
if [[ -n \$GASNET_CONDUIT && ! " $ALL_CONDUITS " =~ " \$GASNET_CONDUIT " ]]; then
  die "invalid UPCXX_NETWORK='\$GASNET_CONDUIT'.\n\$($GMAKE --no-print-directory -s -f '$PWD/Makefile' list-networks 2>&1)"
fi
[[ -z "\$UPCXX_QUIET" ]] && echo 'INFO: may need to build the required runtime.  Please be patient.' >&2
[[ -z "\$GASNET_CONDUIT" ]] && export GASNET_CONDUIT="\$($GMAKE --no-print-directory -s -f '$PWD/Makefile' echo-default-network)"
tmp=\$($GMAKE --no-print-directory -f '$PWD/Makefile' upcxx-meta 2>&1)
[[ \$? -ne 0 ]] && echo "\$tmp" >&2 && die 'build of the required runtime failed.'
meta=\${tmp##*\$'\n'}
if [[ "\$1" == "SET" ]] ; then
  source "\$meta" ""
elif [[ "\$1" == "DUMP" ]] ; then
  i=0
  while read line; do
    [ \$((i++)) == 0 ] && continue # omit she-bang
    [ "\$line" == "" ] && break    # empty line signals end
    echo "\$line"
  done < "\$meta"
else
  exec "\$meta" \$*
fi
EOF
chmod a+rx bin/upcxx bin/upcxx-run bin/upcxx-meta bin/upcxx-info

#
# Remove (potentially out-of-date) generated headers to ensure they are rebuilt
#
rm -Rf bld/upcxx.*/gen_include

#
# Remove any (potentially out-of-date) GASNet builds to ensure they are reconfigured
#
[[ -d bld/gasnet.opt   ]] && rm -Rf bld/gasnet.opt
[[ -d bld/gasnet.debug ]] && rm -Rf bld/gasnet.debug
rm -f bld/gasnet.opt.mak bld/gasnet.debug.mak

#
# Simplify logic when using a GASNet build directory (--enable-single only)
# Only one of gasnet.opt or gasnet.debug is used
#
if [[ "$GASNET_TYPE" == 'build' ]]; then
  rm -f bld/gasnet.$single
  ln -s "$GASNET" bld/gasnet.$single
fi

#
# Final instructions
#
cat << EOF
UPC++ configuration complete.
Recommended next steps:
  1. '$GMAKE_SHORT all'
  2. '$GMAKE_SHORT check'
  3. '$GMAKE_SHORT install'
EOF

#
# Report on bash if we had to search for it
#
if test -n "$UPCXX_REEXEC"; then
  warnings+="\nWARNING: The initial shell was not bash version $UPCXX_BASH_FLOOR or newer.\n"
  warnings+="WARNING: Using '$BASH', found in \$PATH.\n"
  check_known_path "$BASH"
  warnings+="NOTE: Run 'full_path_to_bash $0 [args]' to override the automatic detection.\n"
fi

if [[ -n "$warnings" ]] ; then
  echo -e "\n********\n${warnings}\n********\n"
fi

exit 0