# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
import glob
import itertools
import os
import re
import sys

import llnl.util.tty as tty
import spack.architecture
import spack.util.executable

from spack.operating_systems.mac_os import macos_version, macos_sdk_path


class Gcc(AutotoolsPackage, GNUMirrorPackage):
    """The GNU Compiler Collection includes front ends for C, C++, Objective-C,
    Fortran, Ada, and Go, as well as libraries for these languages."""

    homepage = 'https://gcc.gnu.org'
    gnu_mirror_path = 'gcc/gcc-9.2.0/gcc-9.2.0.tar.xz'
    git      = 'git://gcc.gnu.org/git/gcc.git'
    list_url = 'http://ftp.gnu.org/gnu/gcc/'
    list_depth = 1

    maintainers = ['michaelkuhn']

    version('master', branch='master')

    version('10.2.0', sha256='b8dd4368bb9c7f0b98188317ee0254dd8cc99d1e3a18d0ff146c855fe16c1d8c')
    version('10.1.0', sha256='b6898a23844b656f1b68691c5c012036c2e694ac4b53a8918d4712ad876e7ea2')

    version('9.3.0', sha256='71e197867611f6054aa1119b13a0c0abac12834765fe2d81f35ac57f84f742d1')
    version('9.2.0', sha256='ea6ef08f121239da5695f76c9b33637a118dcf63e24164422231917fa61fb206')
    version('9.1.0', sha256='79a66834e96a6050d8fe78db2c3b32fb285b230b855d0a66288235bc04b327a0')

    version('8.4.0', sha256='e30a6e52d10e1f27ed55104ad233c30bd1e99cfb5ff98ab022dc941edd1b2dd4')
    version('8.3.0', sha256='64baadfe6cc0f4947a84cb12d7f0dfaf45bb58b7e92461639596c21e02d97d2c')
    version('8.2.0', sha256='196c3c04ba2613f893283977e6011b2345d1cd1af9abeac58e916b1aab3e0080')
    version('8.1.0', sha256='1d1866f992626e61349a1ccd0b8d5253816222cdc13390dcfaa74b093aa2b153')

    version('7.5.0', sha256='b81946e7f01f90528a1f7352ab08cc602b9ccc05d4e44da4bd501c5a189ee661')
    version('7.4.0', sha256='eddde28d04f334aec1604456e536416549e9b1aa137fc69204e65eb0c009fe51')
    version('7.3.0', sha256='832ca6ae04636adbb430e865a1451adf6979ab44ca1c8374f61fba65645ce15c')
    version('7.2.0', sha256='1cf7adf8ff4b5aa49041c8734bbcf1ad18cc4c94d0029aae0f4e48841088479a')
    version('7.1.0', sha256='8a8136c235f64c6fef69cac0d73a46a1a09bb250776a050aec8f9fc880bebc17')

    version('6.5.0', sha256='7ef1796ce497e89479183702635b14bb7a46b53249209a5e0f999bebf4740945')
    version('6.4.0', sha256='850bf21eafdfe5cd5f6827148184c08c4a0852a37ccf36ce69855334d2c914d4')
    version('6.3.0', sha256='f06ae7f3f790fbf0f018f6d40e844451e6bc3b7bc96e128e63b09825c1f8b29f')
    version('6.2.0', sha256='9944589fc722d3e66308c0ce5257788ebd7872982a718aa2516123940671b7c5')
    version('6.1.0', sha256='09c4c85cabebb971b1de732a0219609f93fc0af5f86f6e437fd8d7f832f1a351')

    version('5.5.0', sha256='530cea139d82fe542b358961130c69cfde8b3d14556370b65823d2f91f0ced87')
    version('5.4.0', sha256='608df76dec2d34de6558249d8af4cbee21eceddbcb580d666f7a5a583ca3303a')
    version('5.3.0', sha256='b84f5592e9218b73dbae612b5253035a7b34a9a1f7688d2e1bfaaf7267d5c4db')
    version('5.2.0', sha256='5f835b04b5f7dd4f4d2dc96190ec1621b8d89f2dc6f638f9f8bc1b1014ba8cad')
    version('5.1.0', sha256='b7dafdf89cbb0e20333dbf5b5349319ae06e3d1a30bf3515b5488f7e89dca5ad')

    version('4.9.4', sha256='6c11d292cd01b294f9f84c9a59c230d80e9e4a47e5c6355f046bb36d4f358092')
    version('4.9.3', sha256='2332b2a5a321b57508b9031354a8503af6fdfb868b8c1748d33028d100a8b67e')
    version('4.9.2', sha256='2020c98295856aa13fda0f2f3a4794490757fc24bcca918d52cc8b4917b972dd')
    version('4.9.1', sha256='d334781a124ada6f38e63b545e2a3b8c2183049515a1abab6d513f109f1d717e')
    version('4.8.5', sha256='22fb1e7e0f68a63cee631d85b20461d1ea6bda162f03096350e38c8d427ecf23')
    version('4.8.4', sha256='4a80aa23798b8e9b5793494b8c976b39b8d9aa2e53cd5ed5534aff662a7f8695')
    version('4.7.4', sha256='92e61c6dc3a0a449e62d72a38185fda550168a86702dea07125ebd3ec3996282')
    version('4.6.4', sha256='35af16afa0b67af9b8eb15cafb76d2bc5f568540552522f5dc2c88dd45d977e8')
    version('4.5.4', sha256='eef3f0456db8c3d992cbb51d5d32558190bc14f3bc19383dd93acc27acc6befc')

    # We specifically do not add 'all' variant here because:
    # (i) Ada, Go, Jit, and Objective-C++ are not default languages.
    # In that respect, the name 'all' is rather misleading.
    # (ii) Languages other than c,c++,fortran are prone to configure bug in GCC
    # For example, 'java' appears to ignore custom location of zlib
    # (iii) meaning of 'all' changes with GCC version, i.e. 'java' is not part
    # of gcc7. Correctly specifying conflicts() and depends_on() in such a
    # case is a PITA.
    variant('languages',
            default='c,c++,fortran',
            values=('ada', 'brig', 'c', 'c++', 'fortran',
                    'go', 'java', 'jit', 'lto', 'objc', 'obj-c++'),
            multi=True,
            description='Compilers and runtime libraries to build')
    variant('binutils',
            default=False,
            description='Build via binutils')
    variant('piclibs',
            default=False,
            description='Build PIC versions of libgfortran.a and libstdc++.a')
    variant('strip',
            default=False,
            description='Strip executables to reduce installation size')
    variant('nvptx',
            default=False,
            description='Target nvptx offloading to NVIDIA GPUs')
    variant('bootstrap',
            default=False,
            description='add --enable-bootstrap flag for stage3 build')

    depends_on('flex', type='build', when='@master')

    # https://gcc.gnu.org/install/prerequisites.html
    depends_on('gmp@4.3.2:')
    # GCC 7.3 does not compile with newer releases on some platforms, see
    #   https://github.com/spack/spack/issues/6902#issuecomment-433030376
    depends_on('mpfr@2.4.2:3.1.6', when='@:9.9')
    depends_on('mpfr@3.1.0:', when='@10:')
    depends_on('mpc@1.0.1:', when='@4.5:')
    # Already released GCC versions do not support any newer version of ISL
    #   GCC 5.4 https://github.com/spack/spack/issues/6902#issuecomment-433072097
    #   GCC 7.3 https://github.com/spack/spack/issues/6902#issuecomment-433030376
    #   GCC 9+  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86724
    depends_on('isl@0.14', when='@5.0:5.2')
    depends_on('isl@0.15', when='@5.3:5.9')
    depends_on('isl@0.15:0.18', when='@6:8.9')
    depends_on('isl@0.15:0.20', when='@9:9.9')
    depends_on('isl@0.15:', when='@10:')
    depends_on('zlib', when='@6:')
    depends_on('zstd', when='@10:')
    depends_on('iconv', when='platform=darwin')
    depends_on('gnat', when='languages=ada')
    depends_on('binutils~libiberty', when='+binutils', type=('build', 'link', 'run'))
    depends_on('zip', type='build', when='languages=java')
    depends_on('cuda', when='+nvptx')

    # The server is sometimes a bit slow to respond
    timeout = {'timeout': 60}

    resource(name='newlib',
             url='ftp://sourceware.org/pub/newlib/newlib-3.0.0.20180831.tar.gz',
             sha256='3ad3664f227357df15ff34e954bfd9f501009a647667cd307bf0658aefd6eb5b',
             destination='newlibsource',
             when='+nvptx',
             fetch_options=timeout)

    # nvptx-tools does not seem to work as a dependency,
    # but does fine when the source is inside the gcc build directory
    # nvptx-tools doesn't have any releases, so grabbing the last commit
    resource(name='nvptx-tools',
             git='https://github.com/MentorEmbedded/nvptx-tools',
             commit='5f6f343a302d620b0868edab376c00b15741e39e',
             when='+nvptx')

    # TODO: integrate these libraries.
    # depends_on('ppl')
    # depends_on('cloog')

    # https://gcc.gnu.org/install/test.html
    depends_on('dejagnu@1.4.4', type='test')
    depends_on('expect', type='test')
    depends_on('tcl', type='test')
    depends_on('autogen@5.5.4:', type='test')
    depends_on('guile@1.4.1:', type='test')

    # See https://golang.org/doc/install/gccgo#Releases
    provides('golang',        when='languages=go @4.6:')
    provides('golang@:1',     when='languages=go @4.7.1:')
    provides('golang@:1.1',   when='languages=go @4.8:')
    provides('golang@:1.1.2', when='languages=go @4.8.2:')
    provides('golang@:1.2',   when='languages=go @4.9:')
    provides('golang@:1.4',   when='languages=go @5:')
    provides('golang@:1.6.1', when='languages=go @6:')
    provides('golang@:1.8',   when='languages=go @7:')

    # For a list of valid languages for a specific release,
    # run the following command in the GCC source directory:
    #    $ grep ^language= gcc/*/config-lang.in
    # See https://gcc.gnu.org/install/configure.html

    # Support for processing BRIG 1.0 files was added in GCC 7
    # BRIG is a binary format for HSAIL:
    # (Heterogeneous System Architecture Intermediate Language).
    # See https://gcc.gnu.org/gcc-7/changes.html
    conflicts('languages=brig', when='@:6')

    # BRIG does not seem to be supported on macOS
    conflicts('languages=brig', when='platform=darwin')

    # GCC 4.8 added a 'c' language. I'm sure C was always built,
    # but this is the first version that accepts 'c' as a valid language.
    conflicts('languages=c', when='@:4.7')

    # GCC 4.6 added support for the Go programming language.
    # See https://gcc.gnu.org/gcc-4.6/changes.html
    conflicts('languages=go', when='@:4.5')

    # Go is not supported on macOS
    conflicts('languages=go', when='platform=darwin')

    # The GCC Java frontend and associated libjava runtime library
    # have been removed from GCC as of GCC 7.
    # See https://gcc.gnu.org/gcc-7/changes.html
    conflicts('languages=java', when='@7:')

    # GCC 5 added the ability to build GCC as a Just-In-Time compiler.
    # See https://gcc.gnu.org/gcc-5/changes.html
    conflicts('languages=jit', when='@:4')

    # NVPTX offloading supported in 7 and later by limited languages
    conflicts('+nvptx', when='@:6', msg='NVPTX only supported in gcc 7 and above')
    conflicts('languages=ada', when='+nvptx')
    conflicts('languages=brig', when='+nvptx')
    conflicts('languages=go', when='+nvptx')
    conflicts('languages=java', when='+nvptx')
    conflicts('languages=jit', when='+nvptx')
    conflicts('languages=objc', when='+nvptx')
    conflicts('languages=obj-c++', when='+nvptx')
    # NVPTX build disables bootstrap
    conflicts('+binutils', when='+nvptx')

    # Binutils can't build ld on macOS
    conflicts('+binutils', when='platform=darwin')

    # Newer binutils than RHEL's is required to run `as` on some instructions
    # generated by new GCC (see https://github.com/spack/spack/issues/12235)
    conflicts('~binutils', when='@7: os=rhel6',
              msg='New GCC cannot use system assembler on RHEL6')

    if sys.platform == 'darwin':
        # Fix parallel build on APFS filesystem
        # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797
        if macos_version() >= Version('10.13'):
            patch('darwin/apfs.patch', when='@5.5.0,6.1:6.4,7.1:7.3')
            # from homebrew via macports
            # https://trac.macports.org/ticket/56502#no1
            # see also: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83531
            patch('darwin/headers-10.13-fix.patch', when='@5.5.0')
        if macos_version() >= Version('10.14'):
            # Fix system headers for Mojave SDK:
            # https://github.com/Homebrew/homebrew-core/pull/39041
            patch('https://raw.githubusercontent.com/Homebrew/formula-patches/master/gcc/8.3.0-xcode-bug-_Atomic-fix.patch',
                  sha256='33ee92bf678586357ee8ab9d2faddf807e671ad37b97afdd102d5d153d03ca84',
                  when='@6:8')
        if macos_version() >= Version('10.15'):
            # Fix system headers for Catalina SDK
            # (otherwise __OSX_AVAILABLE_STARTING ends up undefined)
            patch('https://raw.githubusercontent.com/Homebrew/formula-patches/b8b8e65e/gcc/9.2.0-catalina.patch',
                  sha256='0b8d14a7f3c6a2f0d2498526e86e088926671b5da50a554ffa6b7f73ac4f132b', when='@9.2.0')
        # Use -headerpad_max_install_names in the build,
        # otherwise updated load commands won't fit in the Mach-O header.
        # This is needed because `gcc` avoids the superenv shim.
        patch('darwin/gcc-7.1.0-headerpad.patch', when='@5:')
        patch('darwin/gcc-6.1.0-jit.patch', when='@5:7')
        patch('darwin/gcc-4.9.patch1', when='@4.9.0:4.9.3')
        patch('darwin/gcc-4.9.patch2', when='@4.9.0:4.9.3')

    patch('piclibs.patch', when='+piclibs')
    patch('gcc-backport.patch', when='@4.7:4.9.2,5:5.3')

    # Backport libsanitizer patch for glibc >= 2.31 and 5.3.0 <= gcc <= 9.2.0
    # https://bugs.gentoo.org/708346
    patch('glibc-2.31-libsanitizer-1.patch', when='@7.1.0:7.5.0,8.1.0:8.3.0,9.0.0:9.2.0')
    patch('glibc-2.31-libsanitizer-1-gcc-6.patch', when='@5.3.0:5.5.0,6.1.0:6.5.0')
    patch('glibc-2.31-libsanitizer-2.patch', when='@8.1.0:8.3.0,9.0.0:9.2.0')
    patch('glibc-2.31-libsanitizer-2-gcc-6.patch', when='@5.3.0:5.5.0,6.1.0:6.5.0')
    patch('glibc-2.31-libsanitizer-2-gcc-7.patch', when='@7.1.0:7.5.0')
    # Older versions do not compile with newer versions of glibc
    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81712
    patch('ucontext_t.patch', when='@4.9,5.1:5.4,6.1:6.4,7.1')
    patch('ucontext_t-java.patch', when='@4.9,5.1:5.4,6.1:6.4 languages=java')
    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81066
    patch('stack_t-4.9.patch', when='@4.9')
    patch('stack_t.patch', when='@5.1:5.4,6.1:6.4,7.1')
    # https://bugs.busybox.net/show_bug.cgi?id=10061
    patch('signal.patch', when='@4.9,5.1:5.4')
    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85835
    patch('sys_ustat.h.patch', when='@5.0:6.4,7.0:7.3,8.1')
    patch('sys_ustat-4.9.patch', when='@4.9')

    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95005
    patch('zstd.patch', when='@10:')

    build_directory = 'spack-build'

    @property
    def executables(self):
        names = [r'gcc', r'[^\w]?g\+\+', r'gfortran']
        suffixes = [r'', r'-mp-\d+\.\d', r'-\d+\.\d', r'-\d+', r'\d\d']
        return [r''.join(x) for x in itertools.product(names, suffixes)]

    @classmethod
    def filter_detected_exes(cls, prefix, exes_in_prefix):
        result = []
        for exe in exes_in_prefix:
            # On systems like Ubuntu we might get multiple executables
            # with the string "gcc" in them. See:
            # https://helpmanual.io/packages/apt/gcc/
            basename = os.path.basename(exe)
            substring_to_be_filtered = [
                'c99-gcc',
                'c89-gcc',
                '-nm',
                '-ar',
                'ranlib',
                'clang'  # clang++ matches g++ -> clan[g++]
            ]
            if any(x in basename for x in substring_to_be_filtered):
                continue
            # Filter out links in favor of real executables on
            # all systems but Cray
            host_platform = str(spack.architecture.platform())
            if os.path.islink(exe) and host_platform != 'cray':
                continue

            result.append(exe)

        return result

    @classmethod
    def determine_version(cls, exe):
        try:
            output = spack.compiler.get_compiler_version_output(
                exe, '--version'
            )
        except Exception:
            output = ''
        # Apple's gcc is actually apple clang, so skip it.
        # Users can add it manually to compilers.yaml at their own risk.
        if 'Apple' in output:
            return None

        version_regex = re.compile(r'([\d\.]+)')
        for vargs in ('-dumpfullversion', '-dumpversion'):
            try:
                output = spack.compiler.get_compiler_version_output(exe, vargs)
                match = version_regex.search(output)
                if match:
                    return match.group(1)
            except spack.util.executable.ProcessError:
                pass
            except Exception as e:
                tty.debug(e)

        return None

    @classmethod
    def determine_variants(cls, exes, version_str):
        languages, compilers = set(), {}
        for exe in exes:
            basename = os.path.basename(exe)
            if 'g++' in basename:
                languages.add('c++')
                compilers['cxx'] = exe
            elif 'gfortran' in basename:
                languages.add('fortran')
                compilers['fortran'] = exe
            elif 'gcc' in basename:
                languages.add('c')
                compilers['c'] = exe
        variant_str = 'languages={0}'.format(','.join(languages))
        return variant_str, {'compilers': compilers}

    @classmethod
    def validate_detected_spec(cls, spec, extra_attributes):
        # For GCC 'compilers' is a mandatory attribute
        msg = ('the extra attribute "compilers" must be set for '
               'the detected spec "{0}"'.format(spec))
        assert 'compilers' in extra_attributes, msg

        compilers = extra_attributes['compilers']
        for constraint, key in {
            'languages=c': 'c',
            'languages=c++': 'cxx',
            'languages=fortran': 'fortran'
        }.items():
            if spec.satisfies(constraint, strict=True):
                msg = '{0} not in {1}'
                assert key in compilers, msg.format(key, spec)

    @property
    def cc(self):
        msg = "cannot retrieve C compiler [spec is not concrete]"
        assert self.spec.concrete, msg
        if self.spec.external:
            return self.spec.extra_attributes['compilers'].get('c', None)
        result = None
        if 'languages=c' in self.spec:
            result = str(self.spec.prefix.bin.gcc)
        return result

    @property
    def cxx(self):
        msg = "cannot retrieve C++ compiler [spec is not concrete]"
        assert self.spec.concrete, msg
        if self.spec.external:
            return self.spec.extra_attributes['compilers'].get('cxx', None)
        result = None
        if 'languages=c++' in self.spec:
            result = os.path.join(self.spec.prefix.bin, 'g++')
        return result

    @property
    def fortran(self):
        msg = "cannot retrieve Fortran compiler [spec is not concrete]"
        assert self.spec.concrete, msg
        if self.spec.external:
            return self.spec.extra_attributes['compilers'].get('fortran', None)
        result = None
        if 'languages=fortran' in self.spec:
            result = str(self.spec.prefix.bin.gfortran)
        return result

    def url_for_version(self, version):
        # This function will be called when trying to fetch from url, before
        # mirrors are tried. It takes care of modifying the suffix of gnu
        # mirror path so that Spack will also look for the correct file in
        # the mirrors
        if (version < Version('6.4.0') and version != Version('5.5.0')) \
                or version == Version('7.1.0'):
            self.gnu_mirror_path = self.gnu_mirror_path.replace('xz', 'bz2')
        return super(Gcc, self).url_for_version(version)

    def patch(self):
        spec = self.spec
        prefix = self.spec.prefix

        # Fix a standard header file for OS X Yosemite that
        # is GCC incompatible by replacing non-GCC compliant macros
        if 'yosemite' in spec.architecture:
            if os.path.isfile('/usr/include/dispatch/object.h'):
                new_dispatch_dir = join_path(prefix, 'include', 'dispatch')
                mkdirp(new_dispatch_dir)
                new_header = join_path(new_dispatch_dir, 'object.h')
                install('/usr/include/dispatch/object.h', new_header)
                filter_file(r'typedef void \(\^dispatch_block_t\)\(void\)',
                            'typedef void* dispatch_block_t',
                            new_header)

        # Use installed libz
        if self.version >= Version('6'):
            filter_file('@zlibdir@',
                        '-L{0}'.format(spec['zlib'].prefix.lib),
                        'gcc/Makefile.in')
            filter_file('@zlibinc@',
                        '-I{0}'.format(spec['zlib'].prefix.include),
                        'gcc/Makefile.in')

    # https://gcc.gnu.org/install/configure.html
    def configure_args(self):
        spec = self.spec

        # Generic options to compile GCC
        options = [
            # Distributor options
            '--with-pkgversion=Spack GCC',
            '--with-bugurl=https://github.com/spack/spack/issues',
            # Xcode 10 dropped 32-bit support
            '--disable-multilib',
            '--enable-languages={0}'.format(
                ','.join(spec.variants['languages'].value)),
            # Drop gettext dependency
            '--disable-nls'
        ]

        # Use installed libz
        if self.version >= Version('6'):
            options.append('--with-system-zlib')

        if 'zstd' in spec:
            options.append('--with-zstd={0}'.format(spec['zstd'].prefix))

        # Enabling language "jit" requires --enable-host-shared.
        if 'languages=jit' in spec:
            options.append('--enable-host-shared')

        # Binutils
        if spec.satisfies('+binutils'):
            binutils = spec['binutils'].prefix.bin
            options.extend([
                '--with-gnu-ld',
                '--with-ld=' + binutils.ld,
                '--with-gnu-as',
                '--with-as=' + binutils.join('as'),
            ])

        # enable_bootstrap
        if spec.satisfies('+bootstrap'):
            options.extend([
                '--enable-bootstrap',
            ])

        # Configure include and lib directories explicitly for these
        # dependencies since the short GCC option assumes that libraries
        # are installed in "/lib" which might not be true on all OS
        # (see #10842)
        #
        # More info at: https://gcc.gnu.org/install/configure.html
        for dep_str in ('mpfr', 'gmp', 'mpc', 'isl'):
            if dep_str not in spec:
                continue

            dep_spec = spec[dep_str]
            include_dir = dep_spec.headers.directories[0]
            lib_dir = dep_spec.libs.directories[0]
            options.extend([
                '--with-{0}-include={1}'.format(dep_str, include_dir),
                '--with-{0}-lib={1}'.format(dep_str, lib_dir)
            ])

        # nvptx-none offloading for host compiler
        if spec.satisfies('+nvptx'):
            options.extend(['--enable-offload-targets=nvptx-none',
                            '--with-cuda-driver-include={0}'.format(
                                spec['cuda'].prefix.include),
                            '--with-cuda-driver-lib={0}'.format(
                                spec['cuda'].libs.directories[0]),
                            '--disable-bootstrap',
                            '--disable-multilib'])

        if sys.platform == 'darwin':
            options.extend([
                '--with-native-system-header-dir=/usr/include',
                '--with-sysroot={0}'.format(macos_sdk_path()),
                '--with-libiconv-prefix={0}'.format(spec['iconv'].prefix)
            ])

        # enable appropriate bootstrapping flags
        stage1_ldflags = str(self.rpath_args)
        boot_ldflags = stage1_ldflags + ' -static-libstdc++ -static-libgcc'
        options.append('--with-stage1-ldflags=' + stage1_ldflags)
        options.append('--with-boot-ldflags=' + boot_ldflags)

        return options

    # run configure/make/make(install) for the nvptx-none target
    # before running the host compiler phases
    @run_before('configure')
    def nvptx_install(self):
        spec = self.spec
        prefix = self.prefix

        if not spec.satisfies('+nvptx'):
            return

        # config.guess returns the host triple, e.g. "x86_64-pc-linux-gnu"
        guess = Executable('./config.guess')
        targetguess = guess(output=str).rstrip('\n')

        options = getattr(self, 'configure_flag_args', [])
        options += ['--prefix={0}'.format(prefix)]

        options += [
            '--with-cuda-driver-include={0}'.format(
                spec['cuda'].prefix.include),
            '--with-cuda-driver-lib={0}'.format(
                spec['cuda'].libs.directories[0]),
        ]

        with working_dir('nvptx-tools'):
            configure = Executable("./configure")
            configure(*options)
            make()
            make('install')

        pattern = join_path(self.stage.source_path, 'newlibsource', '*')
        files = glob.glob(pattern)

        if files:
            symlink(join_path(files[0], 'newlib'), 'newlib')

        # self.build_directory = 'spack-build-nvptx'
        with working_dir('spack-build-nvptx', create=True):

            options = ['--prefix={0}'.format(prefix),
                       '--enable-languages={0}'.format(
                       ','.join(spec.variants['languages'].value)),
                       '--with-mpfr={0}'.format(spec['mpfr'].prefix),
                       '--with-gmp={0}'.format(spec['gmp'].prefix),
                       '--target=nvptx-none',
                       '--with-build-time-tools={0}'.format(
                           join_path(prefix,
                                     'nvptx-none', 'bin')),
                       '--enable-as-accelerator-for={0}'.format(
                           targetguess),
                       '--disable-sjlj-exceptions',
                       '--enable-newlib-io-long-long',
                       ]

            configure = Executable("../configure")
            configure(*options)
            make()
            make('install')

    @property
    def install_targets(self):
        if '+strip' in self.spec:
            return ['install-strip']
        return ['install']

    @property
    def spec_dir(self):
        # e.g. lib/gcc/x86_64-unknown-linux-gnu/4.9.2
        spec_dir = glob.glob('{0}/gcc/*/*'.format(self.prefix.lib))
        return spec_dir[0] if spec_dir else None

    @run_after('install')
    def write_rpath_specs(self):
        """Generate a spec file so the linker adds a rpath to the libs
           the compiler used to build the executable."""
        if not self.spec_dir:
            tty.warn('Could not install specs for {0}.'.format(
                     self.spec.format('{name}{@version}')))
            return

        gcc = self.spec['gcc'].command
        lines = gcc('-dumpspecs', output=str).strip().split('\n')
        specs_file = join_path(self.spec_dir, 'specs')
        with open(specs_file, 'w') as out:
            for line in lines:
                out.write(line + '\n')
                if line.startswith('*link:'):
                    out.write('-rpath {0}:{1} '.format(
                              self.prefix.lib, self.prefix.lib64))
        set_install_permissions(specs_file)

    def setup_run_environment(self, env):
        # Search prefix directory for possibly modified compiler names
        from spack.compilers.gcc import Gcc as Compiler

        # Get the contents of the installed binary directory
        bin_path = self.spec.prefix.bin

        if not os.path.isdir(bin_path):
            return

        bin_contents = os.listdir(bin_path)

        # Find the first non-symlink compiler binary present for each language
        for lang in ['cc', 'cxx', 'fc', 'f77']:
            for filename, regexp in itertools.product(
                    bin_contents,
                    Compiler.search_regexps(lang)
            ):
                if not regexp.match(filename):
                    continue

                abspath = os.path.join(bin_path, filename)
                if os.path.islink(abspath):
                    continue

                # Set the proper environment variable
                env.set(lang.upper(), abspath)
                # Stop searching filename/regex combos for this language
                break
