#							-*- shell-script -*-
#
# Copyright by The HDF Group.
# Copyright by the Board of Trustees of the University of Illinois.
# All rights reserved.
#
# This file is part of HDF5.  The full HDF5 copyright notice, including
# terms governing use, modification, and redistribution, is contained in
# the COPYING file, which can be found at the root of the source code
# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
# If you do not have access to either file, you may request a copy from
# help@hdfgroup.org.


# This file should be sourced into configure if the compiler is the
# GNU g++ compiler or a derivative.  It is careful not to do anything
# if the compiler is not GNU; otherwise `cxx_flags_set' is set to `yes'
#

# Get the compiler version in a way that works for g++
# unless a compiler version is already known
#
#   cxx_vendor:    The compiler name: g++
#   cxx_version:   Version number: 2.91.60, 2.7.2.1
#
if test X = "X$cxx_flags_set"; then
    # PathScale compiler spits out gcc version string too. Need to
    # filter it out.
    # icc beginning with version 12 includes a "gcc version compatiblilty"
    # string, causing the gcc H5_CFLAGS to be erroneously added.  The line
    # "grep -v 'icc version'" causes the discarding of any output
    # containing 'icc version'.  The cc_version for icc is correctly determined
    # and flags added in the intel-flags script.
    cxx_version="`$CXX $CXXFLAGS $H5_CXXFLAGS -v 2>&1 | grep -v 'PathScale' |\
        grep -v 'icc version' |\
        grep 'gcc version' | sed 's/.*gcc version \([-a-z0-9\.]*\).*/\1/'`"
    cxx_vendor=`echo $cxx_version |sed 's/\([a-z]*\).*/\1/'`
    cxx_version=`echo $cxx_version |sed 's/[-a-z]//g'`
    if test X = "X$cxx_vendor" -a X != "X$cxx_version"; then
	cxx_vendor=g++
    fi
    if test "-" != "$cxx_vendor-$cxx_version"; then
	echo "compiler '$CXX' is GNU $cxx_vendor-$cxx_version"
    fi

    # Some version numbers
    cxx_vers_major=`echo $cxx_version | cut -f1 -d.`
    cxx_vers_minor=`echo $cxx_version | cut -f2 -d.`
    cxx_vers_patch=`echo $cxx_version | cut -f3 -d.`
    test -n "$cc_vers_major" || cxx_vers_major=0
    test -n "$cc_vers_minor" || cxx_vers_minor=0
    test -n "$cc_vers_patch" || cxx_vers_patch=0
    cxx_vers_all=`expr $cxx_vers_major '*' 1000000 + $cxx_vers_minor '*' 1000 + $cxx_vers_patch`
fi

# Common g++ flags for various situations
case "$cxx_vendor-$cxx_version" in
  g++*)
    # Architecture-specific flags
    arch=
    case "$host_os-$host_cpu" in
        # FreeBSD sets the information from "uname -m" to the general machine
        # architecture, not the specific CPU for the machine, so even our
        # Pentium II Xeon server is set to "i386".  Once we know we are on a FreeBSD
        # machine, use the "sysctl" command to get the CPU hardware model.
        freebsd*-i386)
            host_cpu_model=`sysctl -n hw.model`
            case "$host_cpu_model" in
                # Hmm.. this might not catch Celerons, but it won't hurt them either...
                *Pro*|*II*|*III*|*IV*|*Athlon*)
                    # architecture-specific optimizations cause problems
                    # for some users who build binaries to be used on
                    # multiple architectures.
                    # arch="-march=i686"
                ;;
            esac
            ;;

        *-i686)
                    # architecture-specific optimizations cause problems
                    # for some users who build binaries to be used on
                    # multiple architectures.
                    # arch="-march=i686"
            ;;
    esac

    # Host-specific flags
    case "`hostname`" in
        sleipnir.ncsa.uiuc.edu)
            arch="$arch -pipe"
            ;;
    esac

    # General (copied from H5_CFLAGS)
    H5_CXXFLAGS="$H5_CXXFLAGS $arch -pedantic -Wall -W -Wundef -Wshadow -Wpointer-arith -Wcast-qual -Wcast-align -Wwrite-strings -Wconversion -Wredundant-decls -Winline"

    # C++-specific
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsign-promo -Woverloaded-virtual -Wold-style-cast -Weffc++ -Wreorder -Wnon-virtual-dtor -Wctor-dtor-privacy -Wabi"

    # Production
    # NDEBUG is handled explicitly by the configure script
    case "$cxx_vendor-$cxx_version" in
      g++-[34].*)
        PROD_CXXFLAGS=
        ;;
      g++-[56].*)
        PROD_CXXFLAGS="-fstdarg-opt"
        ;;
      *)
        PROD_CXXFLAGS="-finline-functions"
        ;;
    esac

    # Debug
    # NDEBUG is handled explicitly by the configure script
    # -g is hanled by the symbols flags
    case "$cxx_vendor-$cxx_version" in
      g++-[56].*)
        DEBUG_CXXFLAGS="-ftrapv -fno-common"
        ;;
      *)
        DEBUG_CXXFLAGS=
        ;;
    esac

    # Symbols
    NO_SYMBOLS_CXXFLAGS="-s"
    SYMBOLS_CXXFLAGS="-g"

    # Profile
    PROFILE_CXXFLAGS="-pg"

    # Optimization
    case "$cxx_vendor-$cxx_version" in
      g++-[34].*)
        HIGH_OPT_CXXFLAGS="-O3"
        DEBUG_OPT_CXXFLAGS=
        ;;
      g++-[56].*)
        HIGH_OPT_CXXFLAGS="-O3"
        DEBUG_OPT_CXXFLAGS="-Og"
        ;;
      *)
        HIGH_OPT_CXXFLAGS="-O"
        DEBUG_OPT_CXXFLAGS=
        ;;
    esac
    NO_OPT_CXXFLAGS="-O0"

    # Flags are set
    cxx_flags_set=yes
    ;;
esac

# Version-specific g++ flags
#
# Please follow the pattern below by adding new versions at the top, copying
# the information from the previous version and adding modifications to that.
case "$cxx_vendor-$cxx_version" in

# Closer to the g++ 5.2 release, we should check for additional flags to
# include and break it out into it's own section, like the other versions
# below. -QAK
  g++-[56]*)

    # Append warning flags from gcc-3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"

    # Append more extra warning flags that only gcc 4.5+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow=5"

    # Append more extra warning flags that only gcc 4.6+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdouble-promotion -Wsuggest-attribute=const -Wtrampolines"

    # Append more extra warning flags that only gcc 4.7+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstack-usage=8192 -Wvector-operation-performance -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"

    # Append more extra warning flags that only gcc 4.8+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsuggest-attribute=format"

    # Append more extra warning flags that only gcc 4.9+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdate-time -Wopenmp-simd"

    # (There was no release of gcc 5.0)

    # Append more extra warning flags that only gcc 5.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Warray-bounds=2"
    ;;

  g++-4.9*)
    # Append warning flags

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc 3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc 3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"

    # Append more extra warning flags that only gcc 4.5+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow=5"

    # Append more extra warning flags that only gcc 4.6+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdouble-promotion -Wsuggest-attribute=const -Wtrampolines"

    # Append more extra warning flags that only gcc 4.7+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstack-usage=8192 -Wvector-operation-performance -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"

    # Append more extra warning flags that only gcc 4.8+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsuggest-attribute=format"

    # Append more extra warning flags that only gcc 4.9+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdate-time -Wopenmp-simd"
    ;;

  g++-4.8*)
    # Append warning flags

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"

    # Append more extra warning flags that only gcc 4.5+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow=5"

    # Append more extra warning flags that only gcc 4.6+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdouble-promotion -Wsuggest-attribute=const -Wtrampolines"

    # Append more extra warning flags that only gcc 4.7+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstack-usage=8192 -Wvector-operation-performance -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"

    # Append more extra warning flags that only gcc 4.8+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsuggest-attribute=format"
    ;;

  g++-4.7*)
    # Append warning flags
    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"

    # Append more extra warning flags that only gcc 4.5+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow=5"

    # Append more extra warning flags that only gcc 4.6+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdouble-promotion -Wsuggest-attribute=const -Wtrampolines"

    # Append more extra warning flags that only gcc 4.7+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstack-usage=8192 -Wvector-operation-performance -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"
    ;;

  g++-4.6*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ knows about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"

    # Append more extra warning flags that only gcc 4.5+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-aliasing -Wstrict-overflow=5"

    # Append more extra warning flags that only gcc 4.6+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wdouble-promotion -Wsuggest-attribute=const -Wtrampolines"
    ;;

  g++-4.5*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc4.0+ knows about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"

    # Append more extra warning flags that only gcc 4.5+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-aliasing -Wstrict-overflow=5"
    ;;

  g++-4.4*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"

    # Append more extra warning flags that only gcc 4.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"
    ;;

  g++-4.3*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations -Wvolatile-register-var"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"

    # Append more extra warning flags that only gcc 4.3+ know about
    #
    # Technically, variable-length arrays are part of the C99 standard, but
    #   we should approach them a bit cautiously... -QAK
    H5_CXXFLAGS="$H5_CXXFLAGS -Wlogical-op -Wvla"
    ;;

  g++-4.2*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations -Wvolatile-register-var"

    # Append more extra warning flags that only gcc 4.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wstrict-overflow"
    ;;

  g++-4.1.*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # Enable more format checking flags, beyond the basic -Wformat included
    # in -Wall
    H5_CXXFLAGS="$H5_CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"

    # Append more extra warning flags that only gcc 4.1+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wunsafe-loop-optimizations -Wvolatile-register-var"
    ;;

  g++-4.0*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # The "format=2" warning generates too many warnings about valid
    # usage in the library.
    #CXXFLAGS="$CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append warning flags from gcc-3.4* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"

    # Append more extra warning flags that only gcc 4.0+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wvariadic-macros -Winit-self -Wmissing-include-dirs -Wswitch-default -Wswitch-enum -Wunused-macros"
    ;;

  g++-3.4*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # The "format=2" warning generates too many warnings about valid
    # usage in the library.
    #CXXFLAGS="$CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append warning flags from gcc-3.3* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"

    # Append more extra warning flags that only gcc3.4+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Winvalid-pch"

    # Replace old -W flag with new -Wextra flag
    H5_CXXFLAGS="`echo $H5_CXXFLAGS | sed -e 's/-W\ /-Wextra\ /g'`"
    ;;

  g++-3.3*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append warning flags from gcc-3.2* case
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # The "format=2" warning generates too many warnings about valid
    # usage in the library.
    #CXXFLAGS="$CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"

    # Append more extra warning flags that only gcc3.3+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wendif-labels"
    ;;

  g++-3.2*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append warning flags from gcc-3* case
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"

    # Append more extra warning flags that only gcc3.2+ know about
    H5_CXXFLAGS="$H5_CXXFLAGS -Wmissing-noreturn -Wpacked -Wdisabled-optimization"

    # The "format=2" warning generates too many warnings about valid
    # usage in the library.
    #CXXFLAGS="$CXXFLAGS -Wformat=2"

    # The "unreachable code" flag generates many spurious C++ warnings.
    # We'll disable it for now.
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wunreachable-code"
    ;;

  g++-3*)
    # Disable warnings about using 'long long' type
    H5_CXXFLAGS="$H5_CXXFLAGS -Wno-long-long"

    # Append some extra warning flags that only gcc3+ know about
    # (don't use -Wpadded flag for normal builds, many of the warnings its
    #   issuing can't be fixed and they are making it hard to detect other,
    #   more important warnings)
    #H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute -Wpadded"
    H5_CXXFLAGS="$H5_CXXFLAGS -Wfloat-equal -Wmissing-format-attribute"
    ;;
esac

# Clear cxx info if no flags set
if test "X$cxx_flags_set" = "X"; then
  cxx_vendor=
  cxx_version=
fi
