# SPDX-License-Identifier: Apache-2.0
# Copyright 2012-2017 The Meson development team

from __future__ import annotations

import typing as T
import functools
import os

from .. import options
from .. import mesonlib
from .compilers import (
    clike_debug_args,
    Compiler,
    CompileCheckMode,
)
from .mixins.clike import CLikeCompiler
from .mixins.gnu import GnuCompiler,  gnu_optimization_args
from .mixins.intel import IntelGnuLikeCompiler, IntelVisualStudioLikeCompiler
from .mixins.clang import ClangCompiler
from .mixins.elbrus import ElbrusCompiler
from .mixins.pgi import PGICompiler

from mesonbuild.mesonlib import (
    version_compare, MesonException,
    LibType,
)

if T.TYPE_CHECKING:
    from ..coredata import MutableKeyedOptionDictType
    from ..dependencies import Dependency
    from ..envconfig import MachineInfo
    from ..environment import Environment
    from ..linkers.linkers import DynamicLinker
    from ..mesonlib import MachineChoice
    from ..build import BuildTarget


class FortranCompiler(CLikeCompiler, Compiler):

    language = 'fortran'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        Compiler.__init__(self, [], exelist, version, for_machine, info,
                          is_cross=is_cross, full_version=full_version, linker=linker)
        CLikeCompiler.__init__(self)

    def has_function(self, funcname: str, prefix: str, env: 'Environment', *,
                     extra_args: T.Optional[T.List[str]] = None,
                     dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
        raise MesonException('Fortran does not have "has_function" capability.\n'
                             'It is better to test if a Fortran capability is working like:\n\n'
                             "meson.get_compiler('fortran').links('block; end block; end program')\n\n"
                             'that example is to see if the compiler has Fortran 2008 Block element.')

    def _get_basic_compiler_args(self, env: 'Environment', mode: CompileCheckMode) -> T.Tuple[T.List[str], T.List[str]]:
        cargs = env.coredata.get_external_args(self.for_machine, self.language)
        largs = env.coredata.get_external_link_args(self.for_machine, self.language)
        return cargs, largs

    def sanity_check(self, work_dir: str, environment: 'Environment') -> None:
        source_name = 'sanitycheckf.f'
        code = '      PROGRAM MAIN\n      PRINT *, "Fortran compilation is working."\n      END\n'
        return self._sanity_check_impl(work_dir, environment, source_name, code)

    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
        return gnu_optimization_args[optimization_level]

    def get_debug_args(self, is_debug: bool) -> T.List[str]:
        return clike_debug_args[is_debug]

    def get_preprocess_only_args(self) -> T.List[str]:
        return ['-cpp'] + super().get_preprocess_only_args()

    def get_module_incdir_args(self) -> T.Tuple[str, ...]:
        return ('-I', )

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['-module', path]

    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str],
                                               build_dir: str) -> T.List[str]:
        for idx, i in enumerate(parameter_list):
            if i[:2] == '-I' or i[:2] == '-L':
                parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))

        return parameter_list

    def module_name_to_filename(self, module_name: str) -> str:
        if '_' in module_name:  # submodule
            s = module_name.lower()
            if self.id in {'gcc', 'intel', 'intel-cl'}:
                filename = s.replace('_', '@') + '.smod'
            elif self.id in {'pgi', 'flang'}:
                filename = s.replace('_', '-') + '.mod'
            else:
                filename = s + '.mod'
        else:  # module
            filename = module_name.lower() + '.mod'

        return filename

    def find_library(self, libname: str, env: 'Environment', extra_dirs: T.List[str],
                     libtype: LibType = LibType.PREFER_SHARED, lib_prefix_warning: bool = True) -> T.Optional[T.List[str]]:
        code = 'stop; end program'
        return self._find_library_impl(libname, env, extra_dirs, code, libtype, lib_prefix_warning)

    def has_multi_arguments(self, args: T.List[str], env: 'Environment') -> T.Tuple[bool, bool]:
        return self._has_multi_arguments(args, env, 'stop; end program')

    def has_multi_link_arguments(self, args: T.List[str], env: 'Environment') -> T.Tuple[bool, bool]:
        return self._has_multi_link_arguments(args, env, 'stop; end program')

    def get_options(self) -> 'MutableKeyedOptionDictType':
        opts = super().get_options()

        key = self.form_compileropt_key('std')
        opts[key] = options.UserComboOption(
            self.make_option_name(key),
            'Fortran language standard to use',
            'none',
            choices=['none'])

        return opts

    def _compile_int(self, expression: str, prefix: str, env: 'Environment',
                     extra_args: T.Union[None, T.List[str], T.Callable[[CompileCheckMode], T.List[str]]],
                     dependencies: T.Optional[T.List['Dependency']]) -> bool:
        # Use a trick for emulating a static assert
        # Taken from https://github.com/j3-fortran/fortran_proposals/issues/70
        t = f'''program test
            {prefix}
            real(merge(kind(1.),-1,({expression}))), parameter :: fail = 1.
        end program test'''
        return self.compiles(t, env, extra_args=extra_args,
                             dependencies=dependencies)[0]

    def cross_compute_int(self, expression: str, low: T.Optional[int], high: T.Optional[int],
                          guess: T.Optional[int], prefix: str, env: 'Environment',
                          extra_args: T.Union[None, T.List[str], T.Callable[[CompileCheckMode], T.List[str]]] = None,
                          dependencies: T.Optional[T.List['Dependency']] = None) -> int:
        # This only difference between this implementation and that of CLikeCompiler
        # is a change in logical conjunction operator (.and. instead of &&)

        # Try user's guess first
        if isinstance(guess, int):
            if self._compile_int(f'{expression} == {guess}', prefix, env, extra_args, dependencies):
                return guess

        # If no bounds are given, compute them in the limit of int32
        maxint = 0x7fffffff
        minint = -0x80000000
        if not isinstance(low, int) or not isinstance(high, int):
            if self._compile_int(f'{expression} >= 0', prefix, env, extra_args, dependencies):
                low = cur = 0
                while self._compile_int(f'{expression} > {cur}', prefix, env, extra_args, dependencies):
                    low = cur + 1
                    if low > maxint:
                        raise mesonlib.EnvironmentException('Cross-compile check overflowed')
                    cur = min(cur * 2 + 1, maxint)
                high = cur
            else:
                high = cur = -1
                while self._compile_int(f'{expression} < {cur}', prefix, env, extra_args, dependencies):
                    high = cur - 1
                    if high < minint:
                        raise mesonlib.EnvironmentException('Cross-compile check overflowed')
                    cur = max(cur * 2, minint)
                low = cur
        else:
            # Sanity check limits given by user
            if high < low:
                raise mesonlib.EnvironmentException('high limit smaller than low limit')
            condition = f'{expression} <= {high} .and. {expression} >= {low}'
            if not self._compile_int(condition, prefix, env, extra_args, dependencies):
                raise mesonlib.EnvironmentException('Value out of given range')

        # Binary search
        while low != high:
            cur = low + int((high - low) / 2)
            if self._compile_int(f'{expression} <= {cur}', prefix, env, extra_args, dependencies):
                high = cur
            else:
                low = cur + 1

        return low

    def compute_int(self, expression: str, low: T.Optional[int], high: T.Optional[int],
                    guess: T.Optional[int], prefix: str, env: 'Environment', *,
                    extra_args: T.Union[None, T.List[str], T.Callable[[CompileCheckMode], T.List[str]]],
                    dependencies: T.Optional[T.List['Dependency']] = None) -> int:
        if extra_args is None:
            extra_args = []
        if self.is_cross:
            return self.cross_compute_int(expression, low, high, guess, prefix, env, extra_args, dependencies)
        t = f'''program test
            {prefix}
            print '(i0)', {expression}
        end program test
        '''
        res = self.run(t, env, extra_args=extra_args,
                       dependencies=dependencies)
        if not res.compiled:
            return -1
        if res.returncode != 0:
            raise mesonlib.EnvironmentException('Could not run compute_int test binary.')
        return int(res.stdout)

    def cross_sizeof(self, typename: str, prefix: str, env: 'Environment', *,
                     extra_args: T.Union[None, T.List[str], T.Callable[[CompileCheckMode], T.List[str]]] = None,
                     dependencies: T.Optional[T.List['Dependency']] = None) -> int:
        if extra_args is None:
            extra_args = []
        t = f'''program test
            use iso_c_binding
            {prefix}
            {typename} :: something
        end program test
        '''
        if not self.compiles(t, env, extra_args=extra_args,
                             dependencies=dependencies)[0]:
            return -1
        return self.cross_compute_int('c_sizeof(x)', None, None, None, prefix + '\nuse iso_c_binding\n' + typename + ' :: x', env, extra_args, dependencies)

    def sizeof(self, typename: str, prefix: str, env: 'Environment', *,
               extra_args: T.Union[None, T.List[str], T.Callable[[CompileCheckMode], T.List[str]]] = None,
               dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[int, bool]:
        if extra_args is None:
            extra_args = []
        if self.is_cross:
            r = self.cross_sizeof(typename, prefix, env, extra_args=extra_args,
                                  dependencies=dependencies)
            return r, False
        t = f'''program test
            use iso_c_binding
            {prefix}
            {typename} :: x
            print '(i0)', c_sizeof(x)
        end program test
        '''
        res = self.cached_run(t, env, extra_args=extra_args,
                              dependencies=dependencies)
        if not res.compiled:
            return -1, False
        if res.returncode != 0:
            raise mesonlib.EnvironmentException('Could not run sizeof test binary.')
        return int(res.stdout), res.cached

    @functools.lru_cache()
    def output_is_64bit(self, env: 'Environment') -> bool:
        '''
        returns true if the output produced is 64-bit, false if 32-bit
        '''
        return self.sizeof('type(c_ptr)', '', env)[0] == 8


class GnuFortranCompiler(GnuCompiler, FortranCompiler):

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 defines: T.Optional[T.Dict[str, str]] = None,
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        GnuCompiler.__init__(self, defines)
        default_warn_args = ['-Wall']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args + ['-Wextra'],
                          '3': default_warn_args + ['-Wextra', '-Wpedantic', '-fimplicit-none'],
                          'everything': default_warn_args + ['-Wextra', '-Wpedantic', '-fimplicit-none']}

    def get_options(self) -> 'MutableKeyedOptionDictType':
        opts = super().get_options()
        fortran_stds = ['legacy', 'f95', 'f2003']
        if version_compare(self.version, '>=4.4.0'):
            fortran_stds += ['f2008']
        if version_compare(self.version, '>=8.0.0'):
            fortran_stds += ['f2018']
        self._update_language_stds(opts, fortran_stds)
        return opts

    def get_option_compile_args(self, target: 'BuildTarget', env: 'Environment', subproject: T.Optional[str] = None) -> T.List[str]:
        args: T.List[str] = []
        std = self.get_compileropt_value('std', env, target, subproject)
        assert isinstance(std, str)
        if std != 'none':
            args.append('-std=' + std)
        return args

    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
        # Disabled until this is fixed:
        # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62162
        # return ['-cpp', '-MD', '-MQ', outtarget]
        return []

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['-J' + path]

    def language_stdlib_only_link_flags(self, env: 'Environment') -> T.List[str]:
        # We need to apply the search prefix here, as these link arguments may
        # be passed to a different compiler with a different set of default
        # search paths, such as when using Clang for C/C++ and gfortran for
        # fortran,
        search_dirs: T.List[str] = []
        for d in self.get_compiler_dirs(env, 'libraries'):
            search_dirs.append(f'-L{d}')
        return search_dirs + ['-lgfortran', '-lm']

    def has_header(self, hname: str, prefix: str, env: 'Environment', *,
                   extra_args: T.Union[None, T.List[str], T.Callable[['CompileCheckMode'], T.List[str]]] = None,
                   dependencies: T.Optional[T.List['Dependency']] = None,
                   disable_cache: bool = False) -> T.Tuple[bool, bool]:
        '''
        Derived from mixins/clike.py:has_header, but without C-style usage of
        __has_include which breaks with GCC-Fortran 10:
        https://github.com/mesonbuild/meson/issues/7017
        '''
        code = f'{prefix}\n#include <{hname}>'
        return self.compiles(code, env, extra_args=extra_args,
                             dependencies=dependencies, mode=CompileCheckMode.PREPROCESS, disable_cache=disable_cache)


class ElbrusFortranCompiler(ElbrusCompiler, FortranCompiler):
    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 defines: T.Optional[T.Dict[str, str]] = None,
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine, is_cross,
                                 info, linker=linker, full_version=full_version)
        ElbrusCompiler.__init__(self)

    def get_options(self) -> 'MutableKeyedOptionDictType':
        opts = super().get_options()
        self._update_language_stds(opts, ['f95', 'f2003', 'f2008', 'gnu', 'legacy', 'f2008ts'])
        return opts

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['-J' + path]


class G95FortranCompiler(FortranCompiler):

    LINKER_PREFIX = '-Wl,'
    id = 'g95'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        default_warn_args = ['-Wall']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args + ['-Wextra'],
                          '3': default_warn_args + ['-Wextra', '-pedantic'],
                          'everything': default_warn_args + ['-Wextra', '-pedantic']}

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['-fmod=' + path]


class SunFortranCompiler(FortranCompiler):

    LINKER_PREFIX = '-Wl,'
    id = 'sun'

    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
        return ['-fpp']

    def get_always_args(self) -> T.List[str]:
        return []

    def get_warn_args(self, level: str) -> T.List[str]:
        return []

    def get_module_incdir_args(self) -> T.Tuple[str, ...]:
        return ('-M', )

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['-moddir=' + path]

    def openmp_flags(self, env: Environment) -> T.List[str]:
        return ['-xopenmp']


class IntelFortranCompiler(IntelGnuLikeCompiler, FortranCompiler):

    id = 'intel'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        # FIXME: Add support for OS X and Windows in detect_fortran_compiler so
        # we are sent the type of compiler
        IntelGnuLikeCompiler.__init__(self)
        self.file_suffixes = ('f90', 'f', 'for', 'ftn', 'fpp', )
        default_warn_args = ['-warn', 'general', '-warn', 'truncated_source']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args + ['-warn', 'unused'],
                          '3': ['-warn', 'all'],
                          'everything': ['-warn', 'all']}

    def get_options(self) -> 'MutableKeyedOptionDictType':
        opts = super().get_options()
        self._update_language_stds(opts, ['none', 'legacy', 'f95', 'f2003', 'f2008', 'f2018'])
        return opts

    def get_option_compile_args(self, target: 'BuildTarget', env: 'Environment', subproject: T.Optional[str] = None) -> T.List[str]:
        args: T.List[str] = []
        std = self.get_compileropt_value('std', env, target, subproject)
        stds = {'legacy': 'none', 'f95': 'f95', 'f2003': 'f03', 'f2008': 'f08', 'f2018': 'f18'}
        assert isinstance(std, str)
        if std != 'none':
            args.append('-stand=' + stds[std])
        return args

    def get_preprocess_only_args(self) -> T.List[str]:
        return ['-cpp', '-EP']

    def get_werror_args(self) -> T.List[str]:
        return ['-warn', 'errors']

    def language_stdlib_only_link_flags(self, env: 'Environment') -> T.List[str]:
        # TODO: needs default search path added
        return ['-lifcore', '-limf']

    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
        return ['-gen-dep=' + outtarget, '-gen-depformat=make']


class IntelLLVMFortranCompiler(IntelFortranCompiler):

    id = 'intel-llvm'


class IntelClFortranCompiler(IntelVisualStudioLikeCompiler, FortranCompiler):

    always_args = ['/nologo']

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice,
                 is_cross: bool, info: 'MachineInfo', target: str,
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        IntelVisualStudioLikeCompiler.__init__(self, target)
        self.file_suffixes = ('f90', 'f', 'for', 'ftn', 'fpp', )

        default_warn_args = ['/warn:general', '/warn:truncated_source']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args + ['/warn:unused'],
                          '3': ['/warn:all'],
                          'everything': ['/warn:all']}

    def get_options(self) -> 'MutableKeyedOptionDictType':
        opts = super().get_options()
        self._update_language_stds(opts, ['none', 'legacy', 'f95', 'f2003', 'f2008', 'f2018'])
        return opts

    def get_option_compile_args(self, target: 'BuildTarget', env: 'Environment', subproject: T.Optional[str] = None) -> T.List[str]:
        args: T.List[str] = []
        std = self.get_compileropt_value('std', env, target, subproject)
        stds = {'legacy': 'none', 'f95': 'f95', 'f2003': 'f03', 'f2008': 'f08', 'f2018': 'f18'}
        assert isinstance(std, str)
        if std != 'none':
            args.append('/stand:' + stds[std])
        return args

    def get_werror_args(self) -> T.List[str]:
        return ['/warn:errors']

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['/module:' + path]


class IntelLLVMClFortranCompiler(IntelClFortranCompiler):

    id = 'intel-llvm-cl'

class PathScaleFortranCompiler(FortranCompiler):

    id = 'pathscale'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        default_warn_args = ['-fullwarn']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args,
                          '3': default_warn_args,
                          'everything': default_warn_args}

    def openmp_flags(self, env: Environment) -> T.List[str]:
        return ['-mp']


class PGIFortranCompiler(PGICompiler, FortranCompiler):

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        PGICompiler.__init__(self)

        default_warn_args = ['-Minform=inform']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args,
                          '3': default_warn_args + ['-Mdclchk'],
                          'everything': default_warn_args + ['-Mdclchk']}

    def language_stdlib_only_link_flags(self, env: 'Environment') -> T.List[str]:
        # TODO: needs default search path added
        return ['-lpgf90rtl', '-lpgf90', '-lpgf90_rpm1', '-lpgf902',
                '-lpgf90rtl', '-lpgftnrtl', '-lrt']


class NvidiaHPC_FortranCompiler(PGICompiler, FortranCompiler):

    id = 'nvidia_hpc'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        PGICompiler.__init__(self)

        default_warn_args = ['-Minform=inform']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args,
                          '3': default_warn_args + ['-Mdclchk'],
                          'everything': default_warn_args + ['-Mdclchk']}


class ClassicFlangFortranCompiler(ClangCompiler, FortranCompiler):

    id = 'flang'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        ClangCompiler.__init__(self, {})
        default_warn_args = ['-Minform=inform']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args,
                          '3': default_warn_args,
                          'everything': default_warn_args}

    def language_stdlib_only_link_flags(self, env: 'Environment') -> T.List[str]:
        # We need to apply the search prefix here, as these link arguments may
        # be passed to a different compiler with a different set of default
        # search paths, such as when using Clang for C/C++ and gfortran for
        # fortran,
        # XXX: Untested....
        search_dirs: T.List[str] = []
        for d in self.get_compiler_dirs(env, 'libraries'):
            search_dirs.append(f'-L{d}')
        return search_dirs + ['-lflang', '-lpgmath']


class ArmLtdFlangFortranCompiler(ClassicFlangFortranCompiler):

    id = 'armltdflang'


class LlvmFlangFortranCompiler(ClangCompiler, FortranCompiler):

    id = 'llvm-flang'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo', linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        ClangCompiler.__init__(self, {})
        default_warn_args = ['-Wall']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args,
                          '3': default_warn_args,
                          'everything': default_warn_args}

    def get_colorout_args(self, colortype: str) -> T.List[str]:
        # not yet supported, see https://github.com/llvm/llvm-project/issues/89888
        return []

    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
        # not yet supported, see https://github.com/llvm/llvm-project/issues/89888
        return []

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        # different syntax from classic flang (which supported `-module`), see
        # https://github.com/llvm/llvm-project/issues/66969
        return ['-module-dir', path]

    def gnu_symbol_visibility_args(self, vistype: str) -> T.List[str]:
        # flang doesn't support symbol visibility flag yet, see
        # https://github.com/llvm/llvm-project/issues/92459
        return []

    def language_stdlib_only_link_flags(self, env: 'Environment') -> T.List[str]:
        # matching setup from ClassicFlangFortranCompiler
        search_dirs: T.List[str] = []
        for d in self.get_compiler_dirs(env, 'libraries'):
            search_dirs.append(f'-L{d}')
        # does not automatically link to Fortran_main anymore after
        # https://github.com/llvm/llvm-project/commit/9d6837d595719904720e5ff68ec1f1a2665bdc2f
        # note that this changed again in flang 19 with
        # https://github.com/llvm/llvm-project/commit/8d5386669ed63548daf1bee415596582d6d78d7d;
        # it seems flang 18 doesn't work if something accidentally includes a program unit, see
        # https://github.com/llvm/llvm-project/issues/92496
        return search_dirs + ['-lFortranRuntime', '-lFortranDecimal']


class Open64FortranCompiler(FortranCompiler):

    id = 'open64'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        default_warn_args = ['-fullwarn']
        self.warn_args = {'0': [],
                          '1': default_warn_args,
                          '2': default_warn_args,
                          '3': default_warn_args,
                          'everything': default_warn_args}

    def openmp_flags(self, env: Environment) -> T.List[str]:
        return ['-mp']


class NAGFortranCompiler(FortranCompiler):

    id = 'nagfor'

    def __init__(self, exelist: T.List[str], version: str, for_machine: MachineChoice, is_cross: bool,
                 info: 'MachineInfo',
                 linker: T.Optional['DynamicLinker'] = None,
                 full_version: T.Optional[str] = None):
        FortranCompiler.__init__(self, exelist, version, for_machine,
                                 is_cross, info, linker=linker,
                                 full_version=full_version)
        # Warnings are on by default; -w disables (by category):
        self.warn_args = {
            '0': ['-w=all'],
            '1': [],
            '2': [],
            '3': [],
            'everything': [],
        }

    def get_always_args(self) -> T.List[str]:
        return self.get_nagfor_quiet(self.version)

    def get_module_outdir_args(self, path: str) -> T.List[str]:
        return ['-mdir', path]

    @staticmethod
    def get_nagfor_quiet(version: str) -> T.List[str]:
        return ['-quiet'] if version_compare(version, '>=7100') else []

    def get_pic_args(self) -> T.List[str]:
        return ['-PIC']

    def get_preprocess_only_args(self) -> T.List[str]:
        return ['-fpp']

    def get_std_exe_link_args(self) -> T.List[str]:
        return self.get_always_args()

    def openmp_flags(self, env: Environment) -> T.List[str]:
        return ['-openmp']