# Copyright 2012-2016 The Meson development team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from . import backends
from .. import environment, mesonlib
from .. import build
from .. import mlog
from .. import dependencies
from .. import compilers
from ..mesonlib import File, MesonException, get_compiler_for_source
from .backends import InstallData
from ..build import InvalidArguments
import os, sys, pickle, re
import subprocess, shutil
from collections import OrderedDict

if mesonlib.is_windows():
    quote_char = '"'
    execute_wrapper = 'cmd /c'
else:
    quote_char = "'"
    execute_wrapper = ''

def ninja_quote(text):
    return text.replace(' ', '$ ').replace(':', '$:')

class RawFilename():
    """
    Used when a filename is already relative to the root build directory, so
    that we know not to add the target's private build directory to it.
    """
    def __init__(self, fname):
        self.fname = fname

    def __str__(self):
        return self.fname

    def __repr__(self):
        return '<RawFilename: {0}>'.format(self.fname)

    def split(self, c):
        return self.fname.split(c)

    def startswith(self, s):
        return self.fname.startswith(s)

class NinjaBuildElement():
    def __init__(self, all_outputs, outfilenames, rule, infilenames):
        if isinstance(outfilenames, str):
            self.outfilenames = [outfilenames]
        else:
            self.outfilenames = outfilenames
        assert(isinstance(rule, str))
        self.rule = rule
        if isinstance(infilenames, str):
            self.infilenames = [infilenames]
        else:
            self.infilenames = infilenames
        self.deps = []
        self.orderdeps = []
        self.elems = []
        self.all_outputs = all_outputs

    def add_dep(self, dep):
        if isinstance(dep, list):
            self.deps += dep
        else:
            self.deps.append(dep)

    def add_orderdep(self, dep):
        if isinstance(dep, list):
            self.orderdeps += dep
        else:
            self.orderdeps.append(dep)

    def add_item(self, name, elems):
        if isinstance(elems, str):
            elems = [elems]
        self.elems.append((name, elems))

    def write(self, outfile):
        self.check_outputs()
        line = 'build %s: %s %s' % (' '.join([ninja_quote(i) for i in self.outfilenames]),\
                                    self.rule,
                                    ' '.join([ninja_quote(i) for i in self.infilenames]))
        if len(self.deps) > 0:
            line += ' | ' + ' '.join([ninja_quote(x) for x in self.deps])
        if len(self.orderdeps) > 0:
            line += ' || ' + ' '.join([ninja_quote(x) for x in self.orderdeps])
        line += '\n'
        # This is the only way I could find to make this work on all
        # platforms including Windows command shell. Slash is a dir separator
        # on Windows, too, so all characters are unambiguous and, more importantly,
        # do not require quoting.
        line = line.replace('\\', '/')
        outfile.write(line)

        for e in self.elems:
            (name, elems) = e
            should_quote = True
            if name == 'DEPFILE' or name == 'DESC' or name == 'pool':
                should_quote = False
            line = ' %s = ' % name
            q_templ = quote_char + "%s" + quote_char
            noq_templ = "%s"
            newelems = []
            for i in elems:
                if not should_quote or i == '&&': # Hackety hack hack
                    templ = noq_templ
                else:
                    templ = q_templ
                i = i.replace('\\', '\\\\')
                if quote_char == '"':
                    i = i.replace('"', '\\"')
                newelems.append(templ % ninja_quote(i))
            line += ' '.join(newelems)
            line += '\n'
            outfile.write(line)
        outfile.write('\n')

    def check_outputs(self):
        for n in self.outfilenames:
            if n in self.all_outputs:
                raise MesonException('Multiple producers for Ninja target "%s". Please rename your targets.' % n)
            self.all_outputs[n] = True

class NinjaBackend(backends.Backend):

    def __init__(self, build):
        super().__init__(build)
        self.ninja_filename = 'build.ninja'
        self.fortran_deps = {}
        self.all_outputs = {}
        self.valgrind = environment.find_valgrind()

    def detect_vs_dep_prefix(self, tempfilename):
        '''VS writes its dependency in a locale dependent format.
        Detect the search prefix to use.'''
        # Of course there is another program called 'cl' on
        # some platforms. Let's just require that on Windows
        # cl points to msvc.
        if not mesonlib.is_windows() or shutil.which('cl') is None:
            return open(tempfilename, 'a')
        filename = os.path.join(self.environment.get_scratch_dir(),
                                'incdetect.c')
        with open(filename, 'w') as f:
            f.write('''#include<stdio.h>
int dummy;
''')

        pc = subprocess.Popen(['cl', '/showIncludes', '/c', 'incdetect.c'],
                              stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE,
                              cwd=self.environment.get_scratch_dir())

        (stdo, _) = pc.communicate()

        for line in stdo.split(b'\r\n'):
            if line.endswith(b'stdio.h'):
                matchstr = b':'.join(line.split(b':')[0:2]) + b':'
                with open(tempfilename, 'ab') as binfile:
                    binfile.write(b'msvc_deps_prefix = ' + matchstr + b'\r\n')
                return open(tempfilename, 'a')
        raise MesonException('Could not determine vs dep dependency prefix string.')

    def generate(self, interp):
        self.interpreter = interp
        outfilename = os.path.join(self.environment.get_build_dir(), self.ninja_filename)
        tempfilename = outfilename + '~'
        with open(tempfilename, 'w') as outfile:
            outfile.write('# This is the build file for project "%s"\n' %
                          self.build.get_project())
            outfile.write('# It is autogenerated by the Meson build system.\n')
            outfile.write('# Do not edit by hand.\n\n')
            outfile.write('ninja_required_version = 1.5.1\n\n')
        with self.detect_vs_dep_prefix(tempfilename) as outfile:
            self.generate_rules(outfile)
            self.generate_phony(outfile)
            outfile.write('# Build rules for targets\n\n')
            for t in self.build.get_targets().values():
                self.generate_target(t, outfile)
            outfile.write('# Test rules\n\n')
            self.generate_tests(outfile)
            outfile.write('# Install rules\n\n')
            self.generate_install(outfile)
            if 'b_coverage' in self.environment.coredata.base_options and \
                    self.environment.coredata.base_options['b_coverage'].value:
                outfile.write('# Coverage rules\n\n')
                self.generate_coverage_rules(outfile)
            outfile.write('# Suffix\n\n')
            self.generate_utils(outfile)
            self.generate_ending(outfile)
        # Only ovewrite the old build file after the new one has been
        # fully created.
        os.replace(tempfilename, outfilename)
        self.generate_compdb()

    # http://clang.llvm.org/docs/JSONCompilationDatabase.html
    def generate_compdb(self):
        ninja_exe = environment.detect_ninja()
        builddir = self.environment.get_build_dir()
        try:
            jsondb = subprocess.check_output([ninja_exe, '-t', 'compdb', 'c_COMPILER', 'cpp_COMPILER'], cwd=builddir)
            with open(os.path.join(builddir, 'compile_commands.json'), 'wb') as f:
                f.write(jsondb)
        except Exception:
            mlog.warning('Could not create compilation database.')

    # Get all generated headers. Any source file might need them so
    # we need to add an order dependency to them.
    def get_generated_headers(self, target):
        header_deps = []
        # XXX: Why don't we add deps to CustomTarget headers here?
        for genlist in target.get_generated_sources():
            if isinstance(genlist, build.CustomTarget):
                continue
            for src in genlist.get_outputs():
                if self.environment.is_header(src):
                    header_deps.append(self.get_target_generated_dir(target, genlist, src))
        # Recurse and find generated headers
        for dep in target.link_targets:
            if isinstance(dep, (build.StaticLibrary, build.SharedLibrary)):
                header_deps += self.get_generated_headers(dep)
        return header_deps

    def get_target_generated_sources(self, target):
        """
        Returns a dictionary with the keys being the path to the file
        (relative to the build directory) of that type and the value
        being the GeneratorList or CustomTarget that generated it.
        """
        srcs = OrderedDict()
        for gensrc in target.get_generated_sources():
            for s in gensrc.get_outputs():
                f = self.get_target_generated_dir(target, gensrc, s)
                srcs[f] = s
        return srcs

    def get_target_sources(self, target):
        srcs = OrderedDict()
        for s in target.get_sources():
            # BuildTarget sources are always mesonlib.File files which are
            # either in the source root, or generated with configure_file and
            # in the build root
            if not isinstance(s, File):
                raise InvalidArguments('All sources in target {!r} must be of type mesonlib.File'.format(t))
            f = s.rel_to_builddir(self.build_to_src)
            srcs[f] = s
        return srcs

    # Languages that can mix with C or C++ but don't support unity builds yet
    # because the syntax we use for unity builds is specific to C/++/ObjC/++.
    langs_cant_unity = ('d', 'fortran')
    def get_target_source_can_unity(self, target, source):
        if isinstance(source, File):
            source = source.fname
        suffix = os.path.splitext(source)[1][1:]
        for lang in self.langs_cant_unity:
            if not lang in target.compilers:
                continue
            if suffix in target.compilers[lang].file_suffixes:
                return False
        return True

    def generate_target(self, target, outfile):
        if isinstance(target, build.CustomTarget):
            self.generate_custom_target(target, outfile)
        if isinstance(target, build.RunTarget):
            self.generate_run_target(target, outfile)
        name = target.get_id()
        if name in self.processed_targets:
            return
        self.processed_targets[name] = True
        # Generate rules for all dependency targets
        self.process_target_dependencies(target, outfile)
        # If target uses a language that cannot link to C objects,
        # just generate for that language and return.
        if isinstance(target, build.Jar):
            self.generate_jar_target(target, outfile)
            return
        if 'rust' in target.compilers:
            self.generate_rust_target(target, outfile)
            return
        if 'cs' in target.compilers:
            self.generate_cs_target(target, outfile)
            return
        if 'swift' in target.compilers:
            self.generate_swift_target(target, outfile)
            return

        # Pre-existing target C/C++ sources to be built; dict of full path to
        # source relative to build root and the original File object.
        target_sources = OrderedDict()
        # GeneratedList and CustomTarget sources to be built; dict of the full
        # path to source relative to build root and the generating target/list
        generated_sources = OrderedDict()
        # Array of sources generated by valac that have to be compiled
        vala_generated_sources = []
        if 'vala' in target.compilers:
            # Sources consumed by valac are filtered out. These only contain
            # C/C++ sources, objects, generated libs, and unknown sources now.
            target_sources, generated_sources, \
            vala_generated_sources = self.generate_vala_compile(target, outfile)
        else:
            target_sources = self.get_target_sources(target)
            generated_sources = self.get_target_generated_sources(target)
        self.scan_fortran_module_outputs(target)
        # Generate rules for GeneratedLists
        self.generate_generator_list_rules(target, outfile)

        # Generate rules for building the remaining source files in this target
        outname = self.get_target_filename(target)
        obj_list = []
        use_pch = self.environment.coredata.base_options.get('b_pch', False)
        is_unity = self.environment.coredata.get_builtin_option('unity')
        if use_pch and target.has_pch():
            pch_objects = self.generate_pch(target, outfile)
        else:
            pch_objects = []
        header_deps = []
        unity_src = []
        unity_deps = [] # Generated sources that must be built before compiling a Unity target.
        header_deps += self.get_generated_headers(target)
        src_list = []

        if is_unity:
            # Warn about incompatible sources if a unity build is enabled
            langs = set(target.compilers.keys())
            langs_cant = langs.intersection(self.langs_cant_unity)
            if langs_cant:
                langs_are = langs = ', '.join(langs_cant).upper()
                langs_are += ' are' if len(langs_cant) > 1 else ' is'
                msg = '{} not supported in Unity builds yet, so {} ' \
                      'sources in the {!r} target will be compiled normally' \
                      ''.format(langs_are, langs, target.name)
                mlog.log(mlog.red('FIXME'), msg)

        # Get a list of all generated *sources* (sources files, headers,
        # objects, etc). Needed to determine the linker.
        generated_output_sources = [] 
        # Get a list of all generated headers that will be needed while building
        # this target's sources (generated sources and pre-existing sources).
        # This will be set as dependencies of all the target's sources. At the
        # same time, also deal with generated sources that need to be compiled.
        generated_source_files = []
        for rel_src, gensrc in generated_sources.items():
            generated_output_sources.append(rel_src)
            raw_src = RawFilename(rel_src)
            if self.environment.is_source(rel_src) and not self.environment.is_header(rel_src):
                if is_unity and self.get_target_source_can_unity(target, rel_src):
                    unity_deps.append(raw_src)
                    abs_src = os.path.join(self.environment.get_build_dir(), rel_src)
                    unity_src.append(abs_src)
                else:
                    generated_source_files.append(raw_src)
            elif self.environment.is_object(rel_src):
                obj_list.append(rel_src)
            elif self.environment.is_library(rel_src):
                pass
            else:
                # Assume anything not specifically a source file is a header. This is because
                # people generate files with weird suffixes (.inc, .fh) that they then include
                # in their source files.
                header_deps.append(raw_src)
        # These are the generated source files that need to be built for use by
        # this target. We create the Ninja build file elements for this here
        # because we need `header_deps` to be fully generated in the above loop.
        for src in generated_source_files:
            src_list.append(src)
            obj_list.append(self.generate_single_compile(target, outfile, src, True,
                                                         header_deps=header_deps))

        # Generate compilation targets for C sources generated from Vala
        # sources. This can be extended to other $LANG->C compilers later if
        # necessary. This needs to be separate for at least Vala
        vala_generated_source_files = []
        for src in vala_generated_sources:
            raw_src = RawFilename(src)
            src_list.append(src)
            if is_unity:
                unity_src.append(os.path.join(self.environment.get_build_dir(), src))
                header_deps.append(raw_src)
            else:
                # Generated targets are ordered deps because the must exist
                # before the sources compiling them are used. After the first
                # compile we get precise dependency info from dep files.
                # This should work in all cases. If it does not, then just
                # move them from orderdeps to proper deps.
                if self.environment.is_header(src):
                    header_deps.append(raw_src)
                else:
                    # We gather all these and generate compile rules below
                    # after `header_deps` (above) is fully generated
                    vala_generated_source_files.append(raw_src)
        for src in vala_generated_source_files:
            # Passing 'vala' here signifies that we want the compile
            # arguments to be specialized for C code generated by
            # valac. For instance, no warnings should be emitted.
            obj_list.append(self.generate_single_compile(target, outfile, src, 'vala', [], header_deps))

        # Generate compile targets for all the pre-existing sources for this target
        for f, src in target_sources.items():
            if not self.environment.is_header(src):
                src_list.append(src)
                if is_unity and self.get_target_source_can_unity(target, src):
                    abs_src = os.path.join(self.environment.get_build_dir(),
                                           src.rel_to_builddir(self.build_to_src))
                    unity_src.append(abs_src)
                else:
                    obj_list.append(self.generate_single_compile(target, outfile, src, False, [], header_deps))
        obj_list += self.flatten_object_list(target)
        if is_unity:
            for src in self.generate_unity_files(target, unity_src):
                obj_list.append(self.generate_single_compile(target, outfile, RawFilename(src), True, unity_deps + header_deps))
        linker = self.determine_linker(target, src_list + generated_output_sources)
        elem = self.generate_link(target, outfile, outname, obj_list, linker, pch_objects)
        self.generate_shlib_aliases(target, self.get_target_dir(target))
        elem.write(outfile)

    def process_target_dependencies(self, target, outfile):
        for t in target.get_dependencies():
            tname = t.get_basename() + t.type_suffix()
            if not tname in self.processed_targets:
                self.generate_target(t, outfile)

    def custom_target_generator_inputs(self, target, outfile):
        for s in target.sources:
            if hasattr(s, 'held_object'):
                s = s.held_object
            if isinstance(s, build.GeneratedList):
                self.generate_genlist_for_target(s, target, outfile)

    def unwrap_dep_list(self, target):
        deps = []
        for i in target.get_dependencies():
            # FIXME, should not grab element at zero but rather expand all.
            if isinstance(i, list):
                i = i[0]
            # Add a dependency on all the outputs of this target
            for output in i.get_outputs():
                deps.append(os.path.join(self.get_target_dir(i), output))
        return deps

    def generate_custom_target(self, target, outfile):
        self.custom_target_generator_inputs(target, outfile)
        (srcs, ofilenames, cmd) = self.eval_custom_target_command(target)
        deps = self.unwrap_dep_list(target)
        desc = 'Generating {0} with a {1} command.'
        if target.build_always:
            deps.append('PHONY')
        if target.depfile is None:
            rulename = 'CUSTOM_COMMAND'
        else:
            rulename = 'CUSTOM_COMMAND_DEP'
        elem = NinjaBuildElement(self.all_outputs, ofilenames, rulename, srcs)
        for i in target.depend_files:
            if isinstance(i, mesonlib.File):
                deps.append(i.rel_to_builddir(self.build_to_src))
            else:
                deps.append(os.path.join(self.build_to_src, i))
        elem.add_dep(deps)
        for d in target.extra_depends:
            # Add a dependency on all the outputs of this target
            for output in d.get_outputs():
                elem.add_dep(os.path.join(self.get_target_dir(d), output))
        # If the target requires capturing stdout, then use the serialized
        # executable wrapper to capture that output and save it to a file.
        #
        # Windows doesn't have -rpath, so for EXEs that need DLLs built within
        # the project, we need to set PATH so the DLLs are found. We use
        # a serialized executable wrapper for that and check if the
        # CustomTarget command needs extra paths first.
        if target.capture or (mesonlib.is_windows() and
                self.determine_windows_extra_paths(target.command[0])):
            exe_data = self.serialise_executable(target.command[0], cmd[1:],
                # All targets are built from the build dir
                self.environment.get_build_dir(),
                capture=ofilenames[0] if target.capture else None)
            cmd = [sys.executable, self.environment.get_build_command(),
                   '--internal', 'exe', exe_data]
            cmd_type = 'meson_exe.py custom'
        else:
            cmd_type = 'custom'

        if target.depfile is not None:
            rel_dfile = os.path.join(self.get_target_dir(target), target.depfile)
            abs_pdir = os.path.join(self.environment.get_build_dir(), self.get_target_dir(target))
            os.makedirs(abs_pdir, exist_ok=True)
            elem.add_item('DEPFILE', rel_dfile)
        elem.add_item('COMMAND', cmd)
        elem.add_item('description',  desc.format(target.name, cmd_type))
        elem.write(outfile)
        self.processed_targets[target.name + target.type_suffix()] = True

    def generate_run_target(self, target, outfile):
        runnerscript = [sys.executable, self.environment.get_build_command(), '--internal', 'commandrunner']
        deps = self.unwrap_dep_list(target)
        arg_strings = []
        for i in target.args:
            if isinstance(i, str):
                arg_strings.append(i)
            elif isinstance(i, (build.BuildTarget, build.CustomTarget)):
                relfname = self.get_target_filename(i)
                arg_strings.append(os.path.join(self.environment.get_build_dir(), relfname))
                deps.append(relfname)
            elif isinstance(i, mesonlib.File):
                relfname = i.rel_to_builddir(self.build_to_src)
                arg_strings.append(os.path.join(self.environment.get_build_dir(), relfname))
            else:
                raise AssertionError('Unreachable code in generate_run_target: ' + str(i))
        elem = NinjaBuildElement(self.all_outputs, target.name, 'CUSTOM_COMMAND', [])
        cmd = runnerscript + [self.environment.get_source_dir(), self.environment.get_build_dir(), target.subdir]
        texe = target.command
        try:
            texe = texe.held_object
        except AttributeError:
            pass
        if isinstance(texe, build.Executable):
            abs_exe = os.path.join(self.environment.get_build_dir(), self.get_target_filename(texe))
            deps.append(self.get_target_filename(texe))
            if self.environment.is_cross_build() and \
               self.environment.cross_info.need_exe_wrapper():
                exe_wrap = self.environment.cross_info.config['binaries'].get('exe_wrapper', None)
                if exe_wrap is not None:
                    cmd += [exe_wrap]
            cmd.append(abs_exe)
        elif isinstance(texe, dependencies.ExternalProgram):
            cmd += texe.get_command()
        elif isinstance(texe, build.CustomTarget):
            deps.append(self.get_target_filename(texe))
            cmd += [os.path.join(self.environment.get_build_dir(), self.get_target_filename(texe))]
        else:
            cmd.append(target.command)
        cmd += arg_strings
        elem.add_dep(deps)
        elem.add_item('COMMAND', cmd)
        elem.add_item('description', 'Running external command %s.' % target.name)
        elem.add_item('pool', 'console')
        elem.write(outfile)
        self.processed_targets[target.name + target.type_suffix()] = True

    def generate_coverage_rules(self, outfile):
        (gcovr_exe, lcov_exe, genhtml_exe) = environment.find_coverage_tools()
        added_rule = False
        if gcovr_exe:
            added_rule = True
            elem = NinjaBuildElement(self.all_outputs, 'coverage-xml', 'CUSTOM_COMMAND', '')
            elem.add_item('COMMAND', [gcovr_exe, '-x', '-r', self.environment.get_source_dir(),\
                                      '-o', os.path.join(self.environment.get_log_dir(), 'coverage.xml')])
            elem.add_item('DESC', 'Generating XML coverage report.')
            elem.write(outfile)
            elem = NinjaBuildElement(self.all_outputs, 'coverage-text', 'CUSTOM_COMMAND', '')
            elem.add_item('COMMAND', [gcovr_exe, '-r', self.environment.get_source_dir(),\
                                      '-o', os.path.join(self.environment.get_log_dir(), 'coverage.txt')])
            elem.add_item('DESC', 'Generating text coverage report.')
            elem.write(outfile)
        if lcov_exe and genhtml_exe:
            added_rule = True
            htmloutdir = os.path.join(self.environment.get_log_dir(), 'coveragereport')
            covinfo = os.path.join(self.environment.get_log_dir(), 'coverage.info')
            phony_elem = NinjaBuildElement(self.all_outputs, 'coverage-html', 'phony', os.path.join(htmloutdir, 'index.html'))
            phony_elem.write(outfile)
            elem = NinjaBuildElement(self.all_outputs, os.path.join(htmloutdir, 'index.html'), 'CUSTOM_COMMAND', '')
            command = [lcov_exe, '--directory', self.environment.get_build_dir(),\
                       '--capture', '--output-file', covinfo, '--no-checksum',\
                       '&&', genhtml_exe, '--prefix', self.environment.get_build_dir(),\
                       '--output-directory', htmloutdir, '--title', 'Code coverage',\
                       '--legend', '--show-details', covinfo]
            elem.add_item('COMMAND', command)
            elem.add_item('DESC', 'Generating HTML coverage report.')
            elem.write(outfile)
        if not added_rule:
            mlog.warning('coverage requested but neither gcovr nor lcov/genhtml found.')

    def generate_install(self, outfile):
        install_data_file = os.path.join(self.environment.get_scratch_dir(), 'install.dat')
        d = InstallData(self.environment.get_source_dir(),
                        self.environment.get_build_dir(),
                        self.environment.get_prefix())
        elem = NinjaBuildElement(self.all_outputs, 'install', 'CUSTOM_COMMAND', 'PHONY')
        elem.add_dep('all')
        elem.add_item('DESC', 'Installing files.')
        elem.add_item('COMMAND', [sys.executable, self.environment.get_build_command(), '--internal', 'install', install_data_file])
        elem.add_item('pool', 'console')
        self.generate_depmf_install(d)
        self.generate_target_install(d)
        self.generate_header_install(d)
        self.generate_man_install(d)
        self.generate_data_install(d)
        self.generate_custom_install_script(d)
        self.generate_subdir_install(d)
        elem.write(outfile)

        with open(install_data_file, 'wb') as ofile:
            pickle.dump(d, ofile)

    def generate_target_install(self, d):
        should_strip = self.environment.coredata.get_builtin_option('strip')
        for t in self.build.get_targets().values():
            if t.should_install():
                # Find the installation directory. FIXME: Currently only one
                # installation directory is supported for each target
                outdir = t.get_custom_install_dir()
                if outdir is not None:
                    pass
                elif isinstance(t, build.SharedLibrary):
                    # For toolchains/platforms that need an import library for
                    # linking (separate from the shared library with all the
                    # code), we need to install the import library (dll.a/.lib)
                    if t.get_import_filename():
                        # Install the import library.
                        i = [self.get_target_filename_for_linking(t),
                             self.environment.get_import_lib_dir(),
                             # It has no aliases, should not be stripped, and
                             # doesn't have an install_rpath
                             [], False, '']
                        d.targets.append(i)
                    outdir = self.environment.get_shared_lib_dir()
                elif isinstance(t, build.StaticLibrary):
                    outdir = self.environment.get_static_lib_dir()
                elif isinstance(t, build.Executable):
                    outdir = self.environment.get_bindir()
                else:
                    # XXX: Add BuildTarget-specific install dir cases here
                    outdir = self.environment.get_libdir()
                if isinstance(t, build.SharedLibrary) or isinstance(t, build.Executable):
                    if t.get_debug_filename():
                        # Install the debug symbols file in the same place as
                        # the target itself. It has no aliases, should not be
                        # stripped, and doesn't have an install_rpath
                        i = [self.get_target_debug_filename(t), outdir, [], False, '']
                        d.targets.append(i)
                if isinstance(t, build.BuildTarget):
                    i = [self.get_target_filename(t), outdir, t.get_aliaslist(),\
                        should_strip, t.install_rpath]
                    d.targets.append(i)
                elif isinstance(t, build.CustomTarget):
                    for output in t.get_outputs():
                        f = os.path.join(self.get_target_dir(t), output)
                        d.targets.append([f, outdir, [], False, None])

    def generate_custom_install_script(self, d):
        d.install_scripts = self.build.install_scripts

    def generate_header_install(self, d):
        incroot = self.environment.get_includedir()
        headers = self.build.get_headers()

        for h in headers:
            outdir = h.get_custom_install_dir()
            if outdir is None:
                outdir = os.path.join(incroot, h.get_install_subdir())
            for f in h.get_sources():
                abspath = os.path.join(self.environment.get_source_dir(), h.get_source_subdir(), f)
                i = [abspath, outdir]
                d.headers.append(i)

    def generate_man_install(self, d):
        manroot = self.environment.get_mandir()
        man = self.build.get_man()
        for m in man:
            for f in m.get_sources():
                num = f.split('.')[-1]
                subdir = m.get_custom_install_dir()
                if subdir is None:
                    subdir = os.path.join(manroot, 'man' + num)
                srcabs = os.path.join(self.environment.get_source_dir(), m.get_source_subdir(), f)
                dstabs = os.path.join(subdir, os.path.split(f)[1] + '.gz')
                i = [srcabs, dstabs]
                d.man.append(i)

    def generate_data_install(self, d):
        data = self.build.get_data()
        for de in data:
            assert(isinstance(de, build.Data))
            subdir = de.install_dir
            for f in de.sources:
                plain_f = os.path.split(f)[1]
                if de.in_sourcetree:
                    srcprefix = self.environment.get_source_dir()
                else:
                    srcprefix = self.environment.get_build_dir()
                srcabs = os.path.join(srcprefix, de.source_subdir, f)
                dstabs = os.path.join(subdir, plain_f)
                i = [srcabs, dstabs]
                d.data.append(i)

    def generate_subdir_install(self, d):
        for sd in self.build.get_install_subdirs():
            inst_subdir = sd.installable_subdir.rstrip('/')
            idir_parts = inst_subdir.split('/')
            if len(idir_parts) > 1:
                subdir = os.path.join(sd.source_subdir, '/'.join(idir_parts[:-1]))
                inst_dir = idir_parts[-1]
            else:
                subdir = sd.source_subdir
                inst_dir = sd.installable_subdir
            src_dir = os.path.join(self.environment.get_source_dir(), subdir)
            dst_dir = os.path.join(self.environment.get_prefix(), sd.install_dir)
            d.install_subdirs.append([src_dir, inst_dir, dst_dir])

    def write_test_suite_targets(self, cmd, outfile):
        suites = {}
        for t in self.build.get_tests():
            for s in t.suite:
                suites[s] = True
        suites = list(suites.keys())
        suites.sort()
        for s in suites:
            if s == '':
                visible_name = 'for top level tests'
            else:
                visible_name = s
            elem = NinjaBuildElement(self.all_outputs, 'test:' + s, 'CUSTOM_COMMAND', ['all', 'PHONY'])
            elem.add_item('COMMAND', cmd + ['--suite=' + s])
            elem.add_item('DESC', 'Running test suite %s.' % visible_name)
            elem.add_item('pool', 'console')
            elem.write(outfile)

            if self.valgrind:
                velem = NinjaBuildElement(self.all_outputs, 'test-valgrind:' + s, 'CUSTOM_COMMAND', ['all', 'PHONY'])
                velem.add_item('COMMAND', cmd + ['--wrapper=' + self.valgrind, '--suite=' + s])
                velem.add_item('DESC', 'Running test suite %s under Valgrind.' % visible_name)
                velem.add_item('pool', 'console')
                velem.write(outfile)

    def generate_tests(self, outfile):
        (test_data, benchmark_data) = self.serialise_tests()
        script_root = self.environment.get_script_dir()
        cmd = [ sys.executable, self.environment.get_build_command(), '--internal', 'test' ]
        if not self.environment.coredata.get_builtin_option('stdsplit'):
            cmd += ['--no-stdsplit']
        if self.environment.coredata.get_builtin_option('errorlogs'):
            cmd += ['--print-errorlogs']
        cmd += [ test_data ]
        elem = NinjaBuildElement(self.all_outputs, 'test', 'CUSTOM_COMMAND', ['all', 'PHONY'])
        elem.add_item('COMMAND', cmd)
        elem.add_item('DESC', 'Running all tests.')
        elem.add_item('pool', 'console')
        elem.write(outfile)
        self.write_test_suite_targets(cmd, outfile)

        if self.valgrind:
            velem = NinjaBuildElement(self.all_outputs, 'test-valgrind', 'CUSTOM_COMMAND', ['all', 'PHONY'])
            velem.add_item('COMMAND', cmd + ['--wrapper=' + self.valgrind])
            velem.add_item('DESC', 'Running test suite under Valgrind.')
            velem.add_item('pool', 'console')
            velem.write(outfile)

        # And then benchmarks.
        cmd = [sys.executable, self.environment.get_build_command(), '--internal', 'benchmark', benchmark_data]
        elem = NinjaBuildElement(self.all_outputs, 'benchmark', 'CUSTOM_COMMAND', ['all', 'PHONY'])
        elem.add_item('COMMAND', cmd)
        elem.add_item('DESC', 'Running benchmark suite.')
        elem.add_item('pool', 'console')
        elem.write(outfile)

    def generate_rules(self, outfile):
        outfile.write('# Rules for compiling.\n\n')
        self.generate_compile_rules(outfile)
        outfile.write('# Rules for linking.\n\n')
        if self.environment.is_cross_build():
            self.generate_static_link_rules(True, outfile)
        self.generate_static_link_rules(False, outfile)
        self.generate_dynamic_link_rules(outfile)
        outfile.write('# Other rules\n\n')
        outfile.write('rule CUSTOM_COMMAND\n')
        outfile.write(' command = $COMMAND\n')
        outfile.write(' description = $DESC\n')
        outfile.write(' restat = 1\n\n')
        # Ninja errors out if you have deps = gcc but no depfile, so we must
        # have two rules for custom commands.
        outfile.write('rule CUSTOM_COMMAND_DEP\n')
        outfile.write(' command = $COMMAND\n')
        outfile.write(' description = $DESC\n')
        outfile.write(' deps = gcc\n')
        outfile.write(' depfile = $DEPFILE\n')
        outfile.write(' restat = 1\n\n')
        outfile.write('rule REGENERATE_BUILD\n')
        c = (quote_char + ninja_quote(sys.executable) + quote_char,
             quote_char + ninja_quote(self.environment.get_build_command())  + quote_char,
             '--internal',
             'regenerate',
             quote_char + ninja_quote(self.environment.get_source_dir())  + quote_char,
             quote_char + ninja_quote(self.environment.get_build_dir())  + quote_char)
        outfile.write(" command = %s %s %s %s %s %s --backend ninja\n" % c)
        outfile.write(' description = Regenerating build files\n')
        outfile.write(' generator = 1\n\n')
        outfile.write('\n')

    def generate_phony(self, outfile):
        outfile.write('# Phony build target, always out of date\n')
        outfile.write('build PHONY: phony\n')
        outfile.write('\n')

    def generate_jar_target(self, target, outfile):
        fname = target.get_filename()
        subdir = target.get_subdir()
        outname_rel = os.path.join(self.get_target_dir(target), fname)
        src_list = target.get_sources()
        class_list = []
        compiler = target.compilers['java']
        c = 'c'
        m = ''
        e = ''
        f = 'f'
        main_class = target.get_main_class()
        if main_class != '':
            e = 'e'
        for src in src_list:
            plain_class_path = self.generate_single_java_compile(src, target, compiler, outfile)
            class_list.append(plain_class_path)
        class_dep_list = [os.path.join(self.get_target_private_dir(target), i) for i in class_list]
        jar_rule = 'java_LINKER'
        commands = [c+m+e+f]
        if e != '':
            commands.append(main_class)
        commands.append(self.get_target_filename(target))
        for cls in class_list:
            commands += ['-C', self.get_target_private_dir(target), cls]
        elem = NinjaBuildElement(self.all_outputs, outname_rel, jar_rule, [])
        elem.add_dep(class_dep_list)
        elem.add_item('ARGS', commands)
        elem.write(outfile)

    def generate_cs_resource_tasks(self, target, outfile):
        args = []
        deps = []
        for r in target.resources:
            rel_sourcefile = os.path.join(self.build_to_src, target.subdir, r)
            if r.endswith('.resources'):
                a = '-resource:' + rel_sourcefile
            elif r.endswith('.txt') or r.endswith('.resx'):
                ofilebase = os.path.splitext(os.path.basename(r))[0] + '.resources'
                ofilename = os.path.join(self.get_target_private_dir(target), ofilebase)
                elem = NinjaBuildElement(self.all_outputs, ofilename, "CUSTOM_COMMAND", rel_sourcefile)
                elem.add_item('COMMAND', ['resgen', rel_sourcefile, ofilename])
                elem.add_item('DESC', 'Compiling resource %s.' % rel_sourcefile)
                elem.write(outfile)
                deps.append(ofilename)
                a = '-resource:' + ofilename
            else:
                raise InvalidArguments('Unknown resource file %s.' % r)
            args.append(a)
        return (args, deps)

    def generate_cs_target(self, target, outfile):
        buildtype = self.environment.coredata.get_builtin_option('buildtype')
        fname = target.get_filename()
        outname_rel = os.path.join(self.get_target_dir(target), fname)
        src_list = target.get_sources()
        compiler = target.compilers['cs']
        rel_srcs = [s.rel_to_builddir(self.build_to_src) for s in src_list]
        deps = []
        commands = target.extra_args.get('cs', [])
        commands += compiler.get_buildtype_args(buildtype)
        if isinstance(target, build.Executable):
            commands.append('-target:exe')
        elif isinstance(target, build.SharedLibrary):
            commands.append('-target:library')
        else:
            raise MesonException('Unknown C# target type.')
        (resource_args, resource_deps) = self.generate_cs_resource_tasks(target, outfile)
        commands += resource_args
        deps += resource_deps
        commands += compiler.get_output_args(outname_rel)
        for l in target.link_targets:
            lname = os.path.join(self.get_target_dir(l), l.get_filename())
            commands += compiler.get_link_args(lname)
            deps.append(lname)
        if '-g' in commands:
            outputs = [outname_rel, outname_rel + '.mdb']
        else:
            outputs = [outname_rel]
        elem = NinjaBuildElement(self.all_outputs, outputs, 'cs_COMPILER', rel_srcs)
        elem.add_dep(deps)
        elem.add_item('ARGS', commands)
        elem.write(outfile)

    def generate_single_java_compile(self, src, target, compiler, outfile):
        args = []
        args += compiler.get_buildtype_args(self.environment.coredata.get_builtin_option('buildtype'))
        args += compiler.get_output_args(self.get_target_private_dir(target))
        for i in target.include_dirs:
            for idir in i.get_incdirs():
                args += ['-sourcepath', os.path.join(self.build_to_src, i.curdir, idir)]
        rel_src = src.rel_to_builddir(self.build_to_src)
        plain_class_path = src.fname[:-4] + 'class'
        rel_obj = os.path.join(self.get_target_private_dir(target), plain_class_path)
        element = NinjaBuildElement(self.all_outputs, rel_obj, compiler.get_language() + '_COMPILER', rel_src)
        element.add_item('ARGS', args)
        element.write(outfile)
        return plain_class_path

    def generate_java_link(self, outfile):
        rule = 'rule java_LINKER\n'
        command = ' command = jar $ARGS\n'
        description = ' description = Creating jar $out.\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)
        outfile.write('\n')

    def determine_dep_vapis(self, target):
        """
        Peek into the sources of BuildTargets we're linking with, and if any of
        them was built with Vala, assume that it also generated a .vapi file of
        the same name as the BuildTarget and return the path to it relative to
        the build directory.
        """
        result = []
        for dep in target.link_targets:
            for i in dep.sources:
                if hasattr(i, 'fname'):
                    i = i.fname
                if i.endswith('vala'):
                    vapiname = dep.name + '.vapi'
                    fullname = os.path.join(self.get_target_dir(dep), vapiname)
                    result.append(fullname)
                    break
        return result

    def split_vala_sources(self, t):
        """
        Splits the target's sources into .vala, .vapi, and other sources.
        Handles both pre-existing and generated sources.

        Returns a tuple (vala, vapi, others) each of which is a dictionary with
        the keys being the path to the file (relative to the build directory)
        and the value being the object that generated or represents the file.
        """
        vala = OrderedDict()
        vapi = OrderedDict()
        others = OrderedDict()
        othersgen = OrderedDict()
        # Split pre-existing sources
        for s in t.get_sources():
            # BuildTarget sources are always mesonlib.File files which are
            # either in the source root, or generated with configure_file and
            # in the build root
            if not isinstance(s, File):
                msg = 'All sources in target {!r} must be of type ' \
                      'mesonlib.File, not {!r}'.format(t, s)
                raise InvalidArguments(msg)
            f = s.rel_to_builddir(self.build_to_src)
            if s.endswith('.vala'):
                srctype = vala
            elif s.endswith('.vapi'):
                srctype = vapi
            else:
                srctype = others
            srctype[f] = s
        # Split generated sources
        for gensrc in t.get_generated_sources():
            for s in gensrc.get_outputs():
                f = self.get_target_generated_dir(t, gensrc, s)
                if s.endswith('.vala'):
                    srctype = vala
                elif s.endswith('.vapi'):
                    srctype = vapi
                # Generated non-Vala (C/C++) sources. Won't be used for
                # generating the Vala compile rule below.
                else:
                    srctype = othersgen
                # Duplicate outputs are disastrous
                if f in srctype:
                    msg = 'Duplicate output {0!r} from {1!r} {2!r}; ' \
                          'conflicts with {0!r} from {4!r} {3!r}' \
                          ''.format(f, type(gensrc).__name__, gensrc.name,
                                    srctype[f].name, type(srctype[f]).__name__)
                    raise InvalidArguments(msg)
                # Store 'somefile.vala': GeneratedList (or CustomTarget)
                srctype[f] = gensrc
        return (vala, vapi, (others, othersgen))

    def generate_vala_compile(self, target, outfile):
        """Vala is compiled into C. Set up all necessary build steps here."""
        (vala_src, vapi_src, other_src) = self.split_vala_sources(target)
        extra_dep_files = []
        if len(vala_src) == 0:
            raise InvalidArguments('Vala library has no Vala source files.')

        valac = target.compilers['vala']
        c_out_dir = self.get_target_private_dir(target)
        # C files generated by valac
        vala_c_src = []
        # Files generated by valac
        valac_outputs = []
        # All sources that are passed to valac on the commandline
        all_files = list(vapi_src.keys())
        for (vala_file, gensrc) in vala_src.items():
            all_files.append(vala_file)
            # Figure out where the Vala compiler will write the compiled C file
            # If the Vala file is in a subdir of the build dir (in our case
            # because it was generated/built by something else), the subdir path
            # components will be preserved in the output path. But if the Vala
            # file is outside the build directory, the path components will be
            # stripped and just the basename will be used.
            if isinstance(gensrc, (build.CustomTarget, build.GeneratedList)) or gensrc.is_built:
                vala_c_file = os.path.splitext(vala_file)[0] + '.c'
            else:
                vala_c_file = os.path.splitext(os.path.basename(vala_file))[0] + '.c'
            # All this will be placed inside the c_out_dir
            vala_c_file = os.path.join(c_out_dir, vala_c_file)
            vala_c_src.append(vala_c_file)
            valac_outputs.append(vala_c_file)

        args = []
        args += self.build.get_global_args(valac)
        args += self.build.get_project_args(valac, target.subproject)
        args += valac.get_buildtype_args(self.environment.coredata.get_builtin_option('buildtype'))
        # Tell Valac to output everything in our private directory. Sadly this
        # means it will also preserve the directory components of Vala sources
        # found inside the build tree (generated sources).
        args += ['-d', c_out_dir]
        args += ['-C']
        if not isinstance(target, build.Executable):
            # Library name
            args += ['--library=' + target.name]
            # Outputted header
            hname = os.path.join(self.get_target_dir(target), target.vala_header)
            args += ['-H', hname]
            valac_outputs.append(hname)
            # Outputted vapi file
            vapiname = os.path.join(self.get_target_dir(target), target.vala_vapi)
            # Force valac to write the vapi and gir files in the target build dir.
            # Without this, it will write it inside c_out_dir
            args += ['--vapi', os.path.join('..', target.vala_vapi)]
            valac_outputs.append(vapiname)
            if isinstance(target.vala_gir, str):
                girname = os.path.join(self.get_target_dir(target), target.vala_gir)
                args += ['--gir', os.path.join('..',  target.vala_gir)]
                valac_outputs.append(girname)
        if self.environment.coredata.get_builtin_option('werror'):
            args += valac.get_werror_args()
        for d in target.get_external_deps():
            if isinstance(d, dependencies.PkgConfigDependency):
                if d.name == 'glib-2.0' and d.version_requirement is not None \
                   and d.version_requirement.startswith(('>=', '==')):
                    args += ['--target-glib', d.version_requirement[2:]]
                args += ['--pkg', d.name]
            elif isinstance(d, dependencies.ExternalLibrary):
                args += d.get_lang_args('vala')
        extra_args = []

        for a in target.extra_args.get('vala', []):
            if isinstance(a, File):
                relname = a.rel_to_builddir(self.build_to_src)
                extra_dep_files.append(relname)
                extra_args.append(relname)
            else:
                extra_args.append(a)
        dependency_vapis = self.determine_dep_vapis(target)
        extra_dep_files += dependency_vapis
        args += extra_args
        element = NinjaBuildElement(self.all_outputs, valac_outputs,
                                    valac.get_language() + '_COMPILER',
                                    all_files + dependency_vapis)
        element.add_item('ARGS', args)
        element.add_dep(extra_dep_files)
        element.write(outfile)
        return other_src[0], other_src[1], vala_c_src

    def generate_rust_target(self, target, outfile):
        rustc = target.compilers['rust']
        relsrc = []
        for i in target.get_sources():
            if not rustc.can_compile(i):
                raise InvalidArguments('Rust target %s contains a non-rust source file.' % target.get_basename())
            relsrc.append(i.rel_to_builddir(self.build_to_src))
        target_name = os.path.join(target.subdir, target.get_filename())
        args = ['--crate-type']
        if isinstance(target, build.Executable):
            cratetype = 'bin'
        elif isinstance(target, build.SharedLibrary):
            cratetype = 'rlib'
        elif isinstance(target, build.StaticLibrary):
            cratetype = 'rlib'
        else:
            raise InvalidArguments('Unknown target type for rustc.')
        args.append(cratetype)
        args += rustc.get_buildtype_args(self.environment.coredata.get_builtin_option('buildtype'))
        depfile = target.name + '.d'
        args += ['--out-dir', target.subdir]
        args += ['--emit', 'dep-info', '--emit', 'link']
        orderdeps = [os.path.join(t.subdir, t.get_filename()) for t in target.link_targets]
        linkdirs = OrderedDict()
        for d in target.link_targets:
            linkdirs[d.subdir] = True
        for d in linkdirs.keys():
            if d == '':
                d = '.'
            args += ['-L', d]
        element = NinjaBuildElement(self.all_outputs, target_name, 'rust_COMPILER', relsrc)
        if len(orderdeps) > 0:
            element.add_orderdep(orderdeps)
        element.add_item('ARGS', args)
        element.add_item('targetdep', depfile)
        element.add_item('cratetype', cratetype)
        element.write(outfile)

    def swift_module_file_name(self, target):
        return os.path.join(self.get_target_private_dir(target),
                            self.target_swift_modulename(target) + '.swiftmodule')

    def target_swift_modulename(self, target):
        return target.name

    def is_swift_target(self, target):
        for s in target.sources:
            if s.endswith('swift'):
                return True
        return False

    def determine_swift_dep_modules(self, target):
        result = []
        for l in target.link_targets:
            if self.is_swift_target(l):
                result.append(self.swift_module_file_name(l))
        return result

    def determine_swift_dep_dirs(self, target):
        result = []
        for l in target.link_targets:
            result.append(self.get_target_private_dir_abs(l))
        return result

    def get_swift_link_deps(self, target):
        result = []
        for l in target.link_targets:
            result.append(self.get_target_filename(l))
        return result

    def split_swift_generated_sources(self, target):
        all_srcs = self.get_target_generated_sources(target)
        srcs = []
        others = []
        for i in all_srcs:
            if i.endswith('.swift'):
                srcs.append(i)
            else:
                others.append(i)
        return (srcs, others)

    def generate_swift_target(self, target, outfile):
        module_name = self.target_swift_modulename(target)
        swiftc = target.compilers['swift']
        abssrc = []
        abs_headers = []
        header_imports = []
        for i in target.get_sources():
            if swiftc.can_compile(i):
                relsrc = i.rel_to_builddir(self.build_to_src)
                abss = os.path.normpath(os.path.join(self.environment.get_build_dir(), relsrc))
                abssrc.append(abss)
            elif self.environment.is_header(i):
                relh = i.rel_to_builddir(self.build_to_src)
                absh = os.path.normpath(os.path.join(self.environment.get_build_dir(), relh))
                abs_headers.append(absh)
                header_imports += swiftc.get_header_import_args(absh)
            else:
                raise InvalidArguments('Swift target %s contains a non-swift source file.' % target.get_basename())
        os.makedirs(self.get_target_private_dir_abs(target), exist_ok=True)
        compile_args = swiftc.get_compile_only_args()
        compile_args += swiftc.get_module_args(module_name)
        link_args = swiftc.get_output_args(os.path.join(self.environment.get_build_dir(), self.get_target_filename(target)))
        rundir = self.get_target_private_dir(target)
        out_module_name = self.swift_module_file_name(target)
        in_module_files = self.determine_swift_dep_modules(target)
        abs_module_dirs = self.determine_swift_dep_dirs(target)
        module_includes = []
        for x in abs_module_dirs:
            module_includes += swiftc.get_include_args(x)
        link_deps = self.get_swift_link_deps(target)
        abs_link_deps = [os.path.join(self.environment.get_build_dir(), x) for x in link_deps]
        (rel_generated, _) = self.split_swift_generated_sources(target)
        abs_generated = [os.path.join(self.environment.get_build_dir(), x) for x in rel_generated]
        # We need absolute paths because swiftc needs to be invoked in a subdir
        # and this is the easiest way about it.
        objects = [] # Relative to swift invocation dir
        rel_objects = [] # Relative to build.ninja
        for i in abssrc + abs_generated:
            base = os.path.split(i)[1]
            oname = os.path.splitext(base)[0] + '.o'
            objects.append(oname)
            rel_objects.append(os.path.join(self.get_target_private_dir(target), oname))

        # Swiftc does not seem to be able to emit objects and module files in one go.
        elem = NinjaBuildElement(self.all_outputs, rel_objects,
                                 'swift_COMPILER',
                                 abssrc)
        elem.add_dep(in_module_files + rel_generated)
        elem.add_dep(abs_headers)
        elem.add_item('ARGS', compile_args + header_imports + abs_generated + module_includes)
        elem.add_item('RUNDIR', rundir)
        elem.write(outfile)
        elem = NinjaBuildElement(self.all_outputs, out_module_name,
                                 'swift_COMPILER',
                                 abssrc)
        elem.add_dep(in_module_files + rel_generated)
        elem.add_item('ARGS', compile_args + abs_generated + module_includes + swiftc.get_mod_gen_args())
        elem.add_item('RUNDIR', rundir)
        elem.write(outfile)
        if isinstance(target, build.StaticLibrary):
            elem = self.generate_link(target, outfile, self.get_target_filename(target),
                               rel_objects, self.build.static_linker)
            elem.write(outfile)
        elif isinstance(target, build.Executable):
            elem = NinjaBuildElement(self.all_outputs, self.get_target_filename(target), 'swift_COMPILER', [])
            elem.add_dep(rel_objects)
            elem.add_dep(link_deps)
            elem.add_item('ARGS', link_args + swiftc.get_std_exe_link_args() + objects + abs_link_deps)
            elem.add_item('RUNDIR', rundir)
            elem.write(outfile)
        else:
            raise MesonException('Swift supports only executable and static library targets.')

    def generate_static_link_rules(self, is_cross, outfile):
        if self.build.has_language('java'):
            if not is_cross:
                self.generate_java_link(outfile)
        if is_cross:
            if self.environment.cross_info.need_cross_compiler():
                static_linker = self.build.static_cross_linker
            else:
                static_linker = self.build.static_linker
            crstr = '_CROSS'
        else:
            static_linker = self.build.static_linker
            crstr = ''
        if static_linker is None:
            return
        rule = 'rule STATIC%s_LINKER\n' % crstr
        if mesonlib.is_windows():
            command_templ = ''' command = %s @$out.rsp
 rspfile = $out.rsp
 rspfile_content = $LINK_ARGS %s $in
'''
        else:
            command_templ = ' command = %s $LINK_ARGS %s $in\n'
        command = command_templ %\
        (' '.join(static_linker.get_exelist()),
         ' '.join(static_linker.get_output_args('$out')))
        description = ' description = Static linking library $out\n\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)

    def generate_dynamic_link_rules(self, outfile):
        ctypes = [(self.build.compilers, False)]
        if self.environment.is_cross_build():
            if self.environment.cross_info.need_cross_compiler():
                ctypes.append((self.build.cross_compilers, True))
            else:
                # Native compiler masquerades as the cross compiler.
                ctypes.append((self.build.compilers, True))
        else:
            ctypes.append((self.build.cross_compilers, True))
        for (complist, is_cross) in ctypes:
            for compiler in complist:
                langname = compiler.get_language()
                if langname == 'java' or langname == 'vala' or\
                 langname == 'rust' or langname == 'cs':
                    continue
                crstr = ''
                cross_args = []
                if is_cross:
                    crstr = '_CROSS'
                    try:
                        cross_args = self.environment.cross_info.config['properties'][langname + '_link_args']
                    except KeyError:
                        pass
                rule = 'rule %s%s_LINKER\n' % (langname, crstr)
                if mesonlib.is_windows():
                    command_template = ''' command = %s @$out.rsp
 rspfile = $out.rsp
 rspfile_content = %s $ARGS  %s $in $LINK_ARGS $aliasing
'''
                else:
                    command_template = ' command = %s %s $ARGS  %s $in $LINK_ARGS $aliasing\n'
                command = command_template % \
                (' '.join(compiler.get_linker_exelist()),\
                 ' '.join(cross_args),\
                 ' '.join(compiler.get_linker_output_args('$out')))
                description = ' description = Linking target $out'
                outfile.write(rule)
                outfile.write(command)
                outfile.write(description)
                outfile.write('\n')
        scriptdir = self.environment.get_script_dir()
        outfile.write('\n')
        symrule = 'rule SHSYM\n'
        symcmd = ' command = "%s" "%s" %s %s %s %s $CROSS\n' % (ninja_quote(sys.executable),
                                                                self.environment.get_build_command(),
                                                                '--internal',
                                                                'symbolextractor',
                                                                '$in',
                                                                '$out')
        synstat = ' restat = 1\n'
        syndesc = ' description = Generating symbol file $out.\n'
        outfile.write(symrule)
        outfile.write(symcmd)
        outfile.write(synstat)
        outfile.write(syndesc)
        outfile.write('\n')

    def generate_java_compile_rule(self, compiler, outfile):
        rule = 'rule %s_COMPILER\n' % compiler.get_language()
        invoc = ' '.join([ninja_quote(i) for i in compiler.get_exelist()])
        command = ' command = %s $ARGS $in\n' % invoc
        description = ' description = Compiling Java object $in.\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)
        outfile.write('\n')

    def generate_cs_compile_rule(self, compiler, outfile):
        rule = 'rule %s_COMPILER\n' % compiler.get_language()
        invoc = ' '.join([ninja_quote(i) for i in compiler.get_exelist()])
        command = ' command = %s $ARGS $in\n' % invoc
        description = ' description = Compiling cs target $out.\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)
        outfile.write('\n')

    def generate_vala_compile_rules(self, compiler, outfile):
        rule = 'rule %s_COMPILER\n' % compiler.get_language()
        invoc = ' '.join([ninja_quote(i) for i in compiler.get_exelist()])
        command = ' command = %s $ARGS $in\n' % invoc
        description = ' description = Compiling Vala source $in.\n'
        restat = ' restat = 1\n' # ValaC does this always to take advantage of it.
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)
        outfile.write(restat)
        outfile.write('\n')

    def generate_rust_compile_rules(self, compiler, outfile):
        rule = 'rule %s_COMPILER\n' % compiler.get_language()
        invoc = ' '.join([ninja_quote(i) for i in compiler.get_exelist()])
        command = ' command = %s $ARGS $in\n' % invoc
        description = ' description = Compiling Rust source $in.\n'
        depfile = ' depfile = $targetdep\n'

        depstyle = ' deps = gcc\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)
        outfile.write(depfile)
        outfile.write(depstyle)
        outfile.write('\n')

    def generate_swift_compile_rules(self, compiler, outfile):
        rule = 'rule %s_COMPILER\n' % compiler.get_language()
        full_exe = [sys.executable,
                    self.environment.get_build_command(),
                    '--internal',
                    'dirchanger',
                    '$RUNDIR'] + compiler.get_exelist()
        invoc = ' '.join([ninja_quote(i) for i in full_exe])
        command = ' command = %s $ARGS $in\n' % invoc
        description = ' description = Compiling Swift source $in.\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(description)
        outfile.write('\n')

    def generate_fortran_dep_hack(self, outfile):
        if mesonlib.is_windows():
            cmd = 'cmd /C ""'
        else:
            cmd = 'true'
        template = '''# Workaround for these issues:
# https://groups.google.com/forum/#!topic/ninja-build/j-2RfBIOd_8
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485
rule FORTRAN_DEP_HACK
 command = %s
 description = Dep hack
 restat = 1

'''
        outfile.write(template % cmd)

    def generate_compile_rule_for(self, langname, compiler, qstr, is_cross, outfile):
        if langname == 'java':
            if not is_cross:
                self.generate_java_compile_rule(compiler, outfile)
            return
        if langname == 'cs':
            if not is_cross:
                self.generate_cs_compile_rule(compiler, outfile)
            return
        if langname == 'vala':
            if not is_cross:
                self.generate_vala_compile_rules(compiler, outfile)
            return
        if langname == 'rust':
            if not is_cross:
                self.generate_rust_compile_rules(compiler, outfile)
            return
        if langname == 'swift':
            if not is_cross:
                self.generate_swift_compile_rules(compiler, outfile)
            return
        if langname == 'fortran':
            self.generate_fortran_dep_hack(outfile)
        if is_cross:
            crstr = '_CROSS'
        else:
            crstr = ''
        rule = 'rule %s%s_COMPILER\n' % (langname, crstr)
        depargs = compiler.get_dependency_gen_args('$out', '$DEPFILE')
        quoted_depargs = []
        for d in depargs:
            if d != '$out' and d != '$in':
                d = qstr % d
            quoted_depargs.append(d)
        cross_args = []
        if is_cross:
            try:
                cross_args = self.environment.cross_info.config['properties'][langname + '_args']
            except KeyError:
                pass
        if mesonlib.is_windows():
            command_template = ''' command = %s @$out.rsp
 rspfile = $out.rsp
 rspfile_content = %s $ARGS %s %s %s $in
'''
        else:
            command_template = ' command = %s %s $ARGS %s %s %s $in\n'
        command = command_template % \
            (' '.join([ninja_quote(i) for i in compiler.get_exelist()]),\
             ' '.join(cross_args),
             ' '.join(quoted_depargs),\
             ' '.join(compiler.get_output_args('$out')),\
             ' '.join(compiler.get_compile_only_args()))
        description = ' description = Compiling %s object $out\n' % langname
        if compiler.get_id() == 'msvc':
            deps = ' deps = msvc\n'
        else:
            deps = ' deps = gcc\n'
            deps += ' depfile = $DEPFILE\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(deps)
        outfile.write(description)
        outfile.write('\n')

    def generate_pch_rule_for(self, langname, compiler, qstr, is_cross, outfile):
        if langname != 'c' and langname != 'cpp':
            return
        if is_cross:
            crstr = '_CROSS'
        else:
            crstr = ''
        rule = 'rule %s%s_PCH\n' % (langname, crstr)
        depargs = compiler.get_dependency_gen_args('$out', '$DEPFILE')
        cross_args = []
        if is_cross:
            try:
                cross_args = self.environment.cross_info.config['properties'][langname + '_args']
            except KeyError:
                pass

        quoted_depargs = []
        for d in depargs:
            if d != '$out' and d != '$in':
                d = qstr % d
            quoted_depargs.append(d)
        if compiler.get_id() == 'msvc':
            output = ''
        else:
            output = ' '.join(compiler.get_output_args('$out'))
        command = " command = %s %s $ARGS %s %s %s $in\n" % \
            (' '.join(compiler.get_exelist()),\
             ' '.join(cross_args),\
             ' '.join(quoted_depargs),\
             output,\
             ' '.join(compiler.get_compile_only_args()))
        description = ' description = Precompiling header %s\n' % '$in'
        if compiler.get_id() == 'msvc':
            deps = ' deps = msvc\n'
        else:
            deps = ' deps = gcc\n'
            deps += ' depfile = $DEPFILE\n'
        outfile.write(rule)
        outfile.write(command)
        outfile.write(deps)
        outfile.write(description)
        outfile.write('\n')

    def generate_compile_rules(self, outfile):
        qstr = quote_char + "%s" + quote_char
        for compiler in self.build.compilers:
            langname = compiler.get_language()
            self.generate_compile_rule_for(langname, compiler, qstr, False, outfile)
            self.generate_pch_rule_for(langname, compiler, qstr, False, outfile)
        if self.environment.is_cross_build():
            # In case we are going a target-only build, make the native compilers
            # masquerade as cross compilers.
            if self.environment.cross_info.need_cross_compiler():
                cclist = self.build.cross_compilers
            else:
                cclist = self.build.compilers
            for compiler in cclist:
                langname = compiler.get_language()
                self.generate_compile_rule_for(langname, compiler, qstr, True, outfile)
                self.generate_pch_rule_for(langname, compiler, qstr, True, outfile)
        outfile.write('\n')

    def generate_generator_list_rules(self, target, outfile):
        # CustomTargets have already written their rules,
        # so write rules for GeneratedLists here
        for genlist in target.get_generated_sources():
            if isinstance(genlist, build.CustomTarget):
                continue
            self.generate_genlist_for_target(genlist, target, outfile)

    def generate_genlist_for_target(self, genlist, target, outfile):
        generator = genlist.get_generator()
        exe = generator.get_exe()
        exe_arr = self.exe_object_to_cmd_array(exe)
        infilelist = genlist.get_inputs()
        outfilelist = genlist.get_outputs()
        base_args = generator.get_arglist()
        extra_dependencies = [os.path.join(self.build_to_src, i) for i in genlist.extra_depends]
        for i in range(len(infilelist)):
            if len(generator.outputs) == 1:
                sole_output = os.path.join(self.get_target_private_dir(target), outfilelist[i])
            else:
                sole_output = ''
            curfile = infilelist[i]
            infilename = os.path.join(self.build_to_src, curfile)
            outfiles = genlist.get_outputs_for(curfile)
            outfiles = [os.path.join(self.get_target_private_dir(target), of) for of in outfiles]
            if generator.depfile is None:
                rulename = 'CUSTOM_COMMAND'
                args = base_args
            else:
                rulename = 'CUSTOM_COMMAND_DEP'
                depfilename = generator.get_dep_outname(infilename)
                depfile = os.path.join(self.get_target_private_dir(target), depfilename)
                args = [x.replace('@DEPFILE@', depfile)  for x in base_args]
            args = [x.replace("@INPUT@", infilename).replace('@OUTPUT@', sole_output)\
                    for x in args]
            args = self.replace_outputs(args, self.get_target_private_dir(target), outfilelist)
            # We have consumed output files, so drop them from the list of remaining outputs.
            if sole_output == '':
                outfilelist = outfilelist[len(generator.outputs):]
            relout = self.get_target_private_dir(target)
            args = [x.replace("@SOURCE_DIR@", self.build_to_src).replace("@BUILD_DIR@", relout)
                    for x in args]
            cmdlist = exe_arr + self.replace_extra_args(args, genlist)
            elem = NinjaBuildElement(self.all_outputs, outfiles, rulename, infilename)
            if generator.depfile is not None:
                elem.add_item('DEPFILE', depfile)
            if len(extra_dependencies) > 0:
                elem.add_dep(extra_dependencies)
            elem.add_item('DESC', 'Generating $out')
            if isinstance(exe, build.BuildTarget):
                elem.add_dep(self.get_target_filename(exe))
            elem.add_item('COMMAND', cmdlist)
            elem.write(outfile)

    def scan_fortran_module_outputs(self, target):
        compiler = None
        for c in self.build.compilers:
            if c.get_language() == 'fortran':
                compiler = c
                break
        if compiler is None:
            self.fortran_deps[target.get_basename()] = {}
            return
        modre = re.compile(r"\s*module\s+(\w+)", re.IGNORECASE)
        module_files = {}
        for s in target.get_sources():
            # FIXME, does not work for generated Fortran sources,
            # but those are really rare. I hope.
            if not compiler.can_compile(s):
                continue
            filename = os.path.join(self.environment.get_source_dir(),
                                    s.subdir, s.fname)
            with open(filename) as f:
                for line in f:
                    modmatch = modre.match(line)
                    if modmatch is not None:
                        modname = modmatch.group(1)
                        if modname.lower() == 'procedure':
                            # MODULE PROCEDURE construct
                            continue
                        if modname in module_files:
                            raise InvalidArguments(
                                'Namespace collision: module %s defined in '
                                'two files %s and %s.' %
                                    (modname, module_files[modname], s))
                        module_files[modname] = s
        self.fortran_deps[target.get_basename()] = module_files

    def get_fortran_deps(self, compiler, src, target):
        mod_files = []
        usere = re.compile(r"\s*use\s+(\w+)", re.IGNORECASE)
        dirname = self.get_target_private_dir(target)
        tdeps= self.fortran_deps[target.get_basename()]
        with open(src) as f:
            for line in f:
                usematch = usere.match(line)
                if usematch is not None:
                    usename = usematch.group(1)
                    if usename not in tdeps:
                        # The module is not provided by any source file. This
                        # is due to:
                        #   a) missing file/typo/etc
                        #   b) using a module provided by the compiler, such as
                        #      OpenMP
                        # There's no easy way to tell which is which (that I
                        # know of) so just ignore this and go on. Ideally we
                        # would print a warning message to the user but this is
                        # a common occurrence, which would lead to lots of
                        # distracting noise.
                        continue
                    mod_source_file = tdeps[usename]
                    # Check if a source uses a module it exports itself.
                    # Potential bug if multiple targets have a file with
                    # the same name.
                    if mod_source_file.fname == os.path.split(src)[1]:
                        continue
                    mod_name = compiler.module_name_to_filename(
                        usematch.group(1))
                    mod_files.append(os.path.join(dirname, mod_name))
        return mod_files

    def get_cross_stdlib_args(self, target, compiler):
        if not target.is_cross:
            return []
        if not self.environment.cross_info.has_stdlib(compiler.language):
            return []
        return compiler.get_no_stdinc_args()

    def get_compile_debugfile_args(self, compiler, target, objfile):
        if compiler.id != 'msvc':
            return []
        # The way MSVC uses PDB files is documented exactly nowhere so
        # the following is what we have been able to decipher via
        # reverse engineering.
        #
        # Each object file gets the path of its PDB file written
        # inside it.  This can be either the final PDB (for, say,
        # foo.exe) or an object pdb (for foo.obj). If the former, then
        # each compilation step locks the pdb file for writing, which
        # is a bottleneck and object files from one target can not be
        # used in a different target. The latter seems to be the
        # sensible one (and what Unix does) but there is a catch.  If
        # you try to use precompiled headers MSVC will error out
        # because both source and pch pdbs go in the same file and
        # they must be the same.
        #
        # This means:
        #
        # - pch files must be compiled anew for every object file (negating
        #   the entire point of having them in the first place)
        # - when using pch, output must go to the target pdb
        #
        # Since both of these are broken in some way, use the one that
        # works for each target. This unfortunately means that you
        # can't combine pch and object extraction in a single target.
        #
        # PDB files also lead to filename collisions. A target foo.exe
        # has a corresponding foo.pdb. A shared library foo.dll _also_
        # has pdb file called foo.pdb. So will a static library
        # foo.lib, which clobbers both foo.pdb _and_ the dll file's
        # export library called foo.lib (by default, currently we name
        # them libfoo.a to avoidt this issue). You can give the files
        # unique names such as foo_exe.pdb but VC also generates a
        # bunch of other files which take their names from the target
        # basename (i.e. "foo") and stomp on each other.
        #
        # CMake solves this problem by doing two things. First of all
        # static libraries do not generate pdb files at
        # all. Presumably you don't need them and VC is smart enough
        # to look up the original data when linking (speculation, not
        # tested). The second solution is that you can only have
        # target named "foo" as an exe, shared lib _or_ static
        # lib. This makes filename collisions not happen. The downside
        # is that you can't have an executable foo that uses a shared
        # library libfoo.so, which is a common idiom on Unix.
        #
        # If you feel that the above is completely wrong and all of
        # this is actually doable, please send patches.

        if target.has_pch():
            tfilename = self.get_target_filename_abs(target)
            return compiler.get_compile_debugfile_args(tfilename, pch=True)
        else:
            return compiler.get_compile_debugfile_args(objfile, pch=False)

    def get_link_debugfile_args(self, linker, target, outname):
        return linker.get_link_debugfile_args(outname)

    def generate_single_compile(self, target, outfile, src, is_generated=False, header_deps=[], order_deps=[]):
        """
        Compiles C/C++, ObjC/ObjC++, and D sources
        """
        if isinstance(src, str) and src.endswith('.h'):
            raise AssertionError('BUG: sources should not contain headers')
        if isinstance(src, RawFilename) and src.fname.endswith('.h'):
            raise AssertionError('BUG: sources should not contain headers')
        extra_orderdeps = []
        compiler = get_compiler_for_source(target.compilers.values(), src)
        commands = []
        # The first thing is implicit include directories: source, build and private.
        commands += compiler.get_include_args(self.get_target_private_dir(target), False)
        # Compiler args for compiling this target
        commands += compilers.get_base_compile_args(self.environment.coredata.base_options,
                                                    compiler)
        # Add the root source and build directories as include dirs
        curdir = target.get_subdir()
        tmppath = os.path.normpath(os.path.join(self.build_to_src, curdir))
        src_inc = compiler.get_include_args(tmppath, False)
        if curdir ==  '':
            curdir = '.'
        build_inc = compiler.get_include_args(curdir, False)
        commands += build_inc + src_inc
        # -I args work differently than other ones. In them the first found
        # directory is used whereas for other flags (such as -ffoo -fno-foo) the
        # latest one is used.  Therefore put the internal include directories
        # here before generating the "basic compiler args" so they override args
        # coming from e.g. pkg-config.
        for i in target.get_include_dirs():
            basedir = i.get_curdir()
            for d in i.get_incdirs():
                expdir =  os.path.join(basedir, d)
                srctreedir = os.path.join(self.build_to_src, expdir)
                bargs = compiler.get_include_args(expdir, i.is_system)
                sargs = compiler.get_include_args(srctreedir, i.is_system)
                commands += bargs
                commands += sargs
            for d in i.get_extra_build_dirs():
                commands += compiler.get_include_args(d, i.is_system)
        commands += self.generate_basic_compiler_args(target, compiler,
                                                      # The code generated by valac is usually crap
                                                      # and has tons of unused variables and such,
                                                      # so disable warnings for Vala C sources.
                                                      no_warn_args=(is_generated == 'vala'))
        for d in target.external_deps:
            if d.need_threads():
                commands += compiler.thread_flags()
                break
        if isinstance(src, RawFilename):
            rel_src = src.fname
            if os.path.isabs(src.fname):
                abs_src = src.fname
            else:
                abs_src = os.path.join(self.environment.get_build_dir(), src.fname)
        elif is_generated:
            raise AssertionError('BUG: broken generated source file handling for {!r}'.format(src))
        else:
            if isinstance(src, File):
                rel_src = src.rel_to_builddir(self.build_to_src)
            else:
                raise InvalidArguments('Invalid source type: {!r}'.format(src))
            abs_src = os.path.join(self.environment.get_build_dir(), rel_src)
        if isinstance(src, (RawFilename, File)):
            src_filename = src.fname
        elif os.path.isabs(src):
            src_filename = os.path.basename(src)
        else:
            src_filename = src
        obj_basename = src_filename.replace('/', '_').replace('\\', '_')
        rel_obj = os.path.join(self.get_target_private_dir(target), obj_basename)
        rel_obj += '.' + self.environment.get_object_suffix()
        dep_file = compiler.depfile_for_object(rel_obj)
        if self.environment.coredata.base_options.get('b_pch', False):
            pchlist = target.get_pch(compiler.language)
        else:
            pchlist = []
        if len(pchlist) == 0:
            pch_dep = []
        else:
            arr = []
            i = os.path.join(self.get_target_private_dir(target), compiler.get_pch_name(pchlist[0]))
            arr.append(i)
            pch_dep = arr
        custom_target_include_dirs = []
        for i in target.get_generated_sources():
            if not isinstance(i, build.CustomTarget):
                continue
            idir = self.get_target_dir(i)
            if idir not in custom_target_include_dirs:
                custom_target_include_dirs.append(idir)
        for i in custom_target_include_dirs:
            commands+= compiler.get_include_args(i, False)
        if self.environment.coredata.base_options.get('b_pch', False):
            commands += self.get_pch_include_args(compiler, target)

        commands += self.get_compile_debugfile_args(compiler, target, rel_obj)
        crstr = ''
        if target.is_cross:
            crstr = '_CROSS'
        compiler_name = '%s%s_COMPILER' % (compiler.get_language(), crstr)
        extra_deps = []
        if compiler.get_language() == 'fortran':
            extra_deps += self.get_fortran_deps(compiler, abs_src, target)
            # Dependency hack. Remove once multiple outputs in Ninja is fixed:
            # https://groups.google.com/forum/#!topic/ninja-build/j-2RfBIOd_8
            for modname, srcfile in self.fortran_deps[target.get_basename()].items():
                modfile = os.path.join(self.get_target_private_dir(target),
                                       compiler.module_name_to_filename(modname))
                if srcfile == src:
                    depelem = NinjaBuildElement(self.all_outputs, modfile, 'FORTRAN_DEP_HACK', rel_obj)
                    depelem.write(outfile)
            commands += compiler.get_module_outdir_args(self.get_target_private_dir(target))

        element = NinjaBuildElement(self.all_outputs, rel_obj, compiler_name, rel_src)
        for d in header_deps:
            if isinstance(d, RawFilename):
                d = d.fname
            elif not self.has_dir_part(d):
                d = os.path.join(self.get_target_private_dir(target), d)
            element.add_dep(d)
        for d in extra_deps:
            element.add_dep(d)
        for d in order_deps:
            if isinstance(d, RawFilename):
                d = d.fname
            elif not self.has_dir_part(d):
                d = os.path.join(self.get_target_private_dir(target), d)
            element.add_orderdep(d)
        element.add_orderdep(pch_dep)
        element.add_orderdep(extra_orderdeps)
        commands = self.dedup_arguments(commands)
        for i in self.get_fortran_orderdeps(target, compiler):
            element.add_orderdep(i)
        element.add_item('DEPFILE', dep_file)
        element.add_item('ARGS', commands)
        element.write(outfile)
        return rel_obj

    def has_dir_part(self, fname):
        # FIXME FIXME: The usage of this is a terrible and unreliable hack
        return '/' in fname or '\\' in fname

    # Fortran is a bit weird (again). When you link against a library, just compiling a source file
    # requires the mod files that are output when single files are built. To do this right we would need to
    # scan all inputs and write out explicit deps for each file. That is stoo slow and too much effort so
    # instead just have an ordered dependendy on the library. This ensures all required mod files are created.
    # The real deps are then detected via dep file generation from the compiler. This breaks on compilers that
    # produce incorrect dep files but such is life.
    def get_fortran_orderdeps(self, target, compiler):
        if compiler.language != 'fortran':
            return []
        return [os.path.join(self.get_target_dir(lt), lt.get_filename()) for lt in target.link_targets]

    def generate_msvc_pch_command(self, target, compiler, pch):
        if len(pch) != 2:
            raise RuntimeError('MSVC requires one header and one source to produce precompiled headers.')
        header = pch[0]
        source = pch[1]
        pchname = compiler.get_pch_name(header)
        dst = os.path.join(self.get_target_private_dir(target), pchname)

        commands = []
        commands += self.generate_basic_compiler_args(target, compiler)
        just_name = os.path.split(header)[1]
        (objname, pch_args) = compiler.gen_pch_args(just_name, source, dst)
        commands += pch_args
        commands += self.get_compile_debugfile_args(compiler, target, objname)
        dep = dst + '.' + compiler.get_depfile_suffix()
        return (commands, dep, dst, [objname])

    def generate_gcc_pch_command(self, target, compiler, pch):
        commands = []
        commands += self.generate_basic_compiler_args(target, compiler)
        dst = os.path.join(self.get_target_private_dir(target),
                           os.path.split(pch)[-1] + '.' + compiler.get_pch_suffix())
        dep = dst + '.' + compiler.get_depfile_suffix()
        return (commands, dep, dst, []) # Gcc does not create an object file during pch generation.

    def generate_pch(self, target, outfile):
        cstr = ''
        pch_objects = []
        if target.is_cross:
            cstr = '_CROSS'
        for lang in ['c', 'cpp']:
            pch = target.get_pch(lang)
            if len(pch) == 0:
                continue
            if '/' not in pch[0] or '/' not in pch[-1]:
                msg = 'Precompiled header of {!r} must not be in the same ' \
                      'directory as source, please put it in a subdirectory.' \
                      ''.format(target.get_basename())
                raise InvalidArguments(msg)
            compiler = target.compilers[lang]
            if compiler.id == 'msvc':
                src = os.path.join(self.build_to_src, target.get_source_subdir(), pch[-1])
                (commands, dep, dst, objs) = self.generate_msvc_pch_command(target, compiler, pch)
                extradep = os.path.join(self.build_to_src, target.get_source_subdir(), pch[0])
            else:
                src = os.path.join(self.build_to_src, target.get_source_subdir(), pch[0])
                (commands, dep, dst, objs) = self.generate_gcc_pch_command(target, compiler, pch[0])
                extradep = None
            pch_objects += objs
            rulename = compiler.get_language() + cstr + '_PCH'
            elem = NinjaBuildElement(self.all_outputs, dst, rulename, src)
            if extradep is not None:
                elem.add_dep(extradep)
            elem.add_item('ARGS', commands)
            elem.add_item('DEPFILE', dep)
            elem.write(outfile)
        return pch_objects

    def generate_shsym(self, outfile, target):
        target_name = self.get_target_filename(target)
        targetdir = self.get_target_private_dir(target)
        symname = os.path.join(targetdir, target_name + '.symbols')
        elem = NinjaBuildElement(self.all_outputs, symname, 'SHSYM', target_name)
        if self.environment.is_cross_build() and self.environment.cross_info.need_cross_compiler():
            elem.add_item('CROSS', '--cross-host=' + self.environment.cross_info.config['host_machine']['system'])
        elem.write(outfile)

    def get_cross_stdlib_link_args(self, target, linker):
        if isinstance(target, build.StaticLibrary) or not target.is_cross:
            return []
        if not self.environment.cross_info.has_stdlib(linker.language):
            return []
        return linker.get_no_stdlib_link_args()

    def generate_link(self, target, outfile, outname, obj_list, linker, extra_args=[]):
        if isinstance(target, build.StaticLibrary):
            linker_base = 'STATIC'
        else:
            linker_base = linker.get_language() # Fixme.
        if isinstance(target, build.SharedLibrary):
            self.generate_shsym(outfile, target)
        crstr = ''
        if target.is_cross:
            crstr = '_CROSS'
        linker_rule = linker_base + crstr + '_LINKER'
        abspath = os.path.join(self.environment.get_build_dir(), target.subdir)
        commands = []
        if not isinstance(target, build.StaticLibrary):
            commands += self.build.get_project_link_args(linker, target.subproject)
            commands += self.build.get_global_link_args(linker)
        commands += self.get_cross_stdlib_link_args(target, linker)
        commands += linker.get_linker_always_args()
        if not isinstance(target, build.StaticLibrary):
            commands += compilers.get_base_link_args(self.environment.coredata.base_options,
                                                     linker)
        commands += linker.get_buildtype_linker_args(self.environment.coredata.get_builtin_option('buildtype'))
        commands += linker.get_option_link_args(self.environment.coredata.compiler_options)
        commands += self.get_link_debugfile_args(linker, target, outname)
        if not(isinstance(target, build.StaticLibrary)):
            commands += self.environment.coredata.external_link_args[linker.get_language()]
        if isinstance(target, build.Executable):
            commands += linker.get_std_exe_link_args()
        elif isinstance(target, build.SharedLibrary):
            commands += linker.get_std_shared_lib_link_args()
            commands += linker.get_pic_args()
            if hasattr(target, 'soversion'):
                soversion = target.soversion
            else:
                soversion = None
            commands += linker.get_soname_args(target.prefix, target.name, target.suffix, abspath, soversion)
            # This is only visited when using the Visual Studio toolchain
            if target.vs_module_defs and hasattr(linker, 'gen_vs_module_defs_args'):
                commands += linker.gen_vs_module_defs_args(target.vs_module_defs.rel_to_builddir(self.build_to_src))
            # This is only visited when building for Windows using either MinGW/GCC or Visual Studio
            if target.import_filename:
                commands += linker.gen_import_library_args(os.path.join(target.subdir, target.import_filename))
        elif isinstance(target, build.StaticLibrary):
            commands += linker.get_std_link_args()
        else:
            raise RuntimeError('Unknown build target type.')
        # Link arguments of static libraries are not put in the command line of
        # the library. They are instead appended to the command line where
        # the static library is used.
        if linker_base == 'STATIC':
            dependencies = []
        else:
            dependencies = target.get_dependencies()
        commands += self.build_target_link_arguments(linker, dependencies)
        for d in target.external_deps:
            if d.need_threads():
                commands += linker.thread_link_flags()
        if not isinstance(target, build.StaticLibrary):
            commands += target.link_args
            # External deps must be last because target link libraries may depend on them.
            for dep in target.get_external_deps():
                commands += dep.get_link_args()
            for d in target.get_dependencies():
                if isinstance(d, build.StaticLibrary):
                    for dep in d.get_external_deps():
                        commands += dep.get_link_args()
        commands += linker.build_rpath_args(self.environment.get_build_dir(),\
                                            self.determine_rpath_dirs(target), target.install_rpath)
        custom_target_libraries = self.get_custom_target_provided_libraries(target)
        commands += extra_args
        commands += custom_target_libraries
        commands = linker.unix_link_flags_to_native(self.dedup_arguments(commands))
        dep_targets = [self.get_dependency_filename(t) for t in dependencies]
        dep_targets += [os.path.join(self.environment.source_dir,
                                     target.subdir, t) for t in target.link_depends]
        elem = NinjaBuildElement(self.all_outputs, outname, linker_rule, obj_list)
        elem.add_dep(dep_targets + custom_target_libraries)
        elem.add_item('LINK_ARGS', commands)
        return elem

    def determine_rpath_dirs(self, target):
        link_deps = target.get_all_link_deps()
        result = []
        for ld in link_deps:
            prospective = self.get_target_dir(ld)
            if not prospective in result:
                result.append(prospective)
        return result

    def get_dependency_filename(self, t):
        if isinstance(t, build.SharedLibrary):
            return os.path.join(self.get_target_private_dir(t), self.get_target_filename(t) + '.symbols')
        return self.get_target_filename(t)

    def generate_shlib_aliases(self, target, outdir):
        basename = target.get_filename()
        aliases = target.get_aliaslist()
        for alias in aliases:
            aliasfile = os.path.join(self.environment.get_build_dir(), outdir, alias)
            try:
                os.remove(aliasfile)
            except Exception:
                pass
            try:
                os.symlink(basename, aliasfile)
            except NotImplementedError:
                mlog.debug("Library versioning disabled because symlinks are not supported.")
            except OSError:
                mlog.debug("Library versioning disabled because we do not have symlink creation privileges.")

    def generate_gcov_clean(self, outfile):
            gcno_elem = NinjaBuildElement(self.all_outputs, 'clean-gcno', 'CUSTOM_COMMAND', 'PHONY')
            script_root = self.environment.get_script_dir()
            clean_script = os.path.join(script_root, 'delwithsuffix.py')
            gcno_elem.add_item('COMMAND', [sys.executable, clean_script, '.', 'gcno'])
            gcno_elem.add_item('description', 'Deleting gcno files')
            gcno_elem.write(outfile)

            gcda_elem = NinjaBuildElement(self.all_outputs, 'clean-gcda', 'CUSTOM_COMMAND', 'PHONY')
            script_root = self.environment.get_script_dir()
            clean_script = os.path.join(script_root, 'delwithsuffix.py')
            gcda_elem.add_item('COMMAND', [sys.executable, clean_script, '.', 'gcda'])
            gcda_elem.add_item('description', 'Deleting gcda files')
            gcda_elem.write(outfile)

    # For things like scan-build and other helper tools we might have.
    def generate_utils(self, outfile):
        cmd = [sys.executable, self.environment.get_build_command(),
               '--internal', 'scanbuild', self.environment.source_dir, self.environment.build_dir,
               sys.executable, self.environment.get_build_command()]
        elem = NinjaBuildElement(self.all_outputs, 'scan-build', 'CUSTOM_COMMAND', 'PHONY')
        elem.add_item('COMMAND', cmd)
        elem.add_item('pool', 'console')
        elem.write(outfile)

    def generate_ending(self, outfile):
        targetlist = []
        for t in self.build.get_targets().values():
            # RunTargets are meant to be invoked manually
            if isinstance(t, build.RunTarget):
                continue
            # CustomTargets that aren't installed should only be built if they
            # are used by something else or are meant to be always built
            if isinstance(t, build.CustomTarget) and not (t.install or t.build_always):
                continue
            # Add the first output of each target to the 'all' target so that
            # they are all built
            targetlist.append(os.path.join(self.get_target_dir(t), t.get_outputs()[0]))

        elem = NinjaBuildElement(self.all_outputs, 'all', 'phony', targetlist)
        elem.write(outfile)

        default = 'default all\n\n'
        outfile.write(default)

        ninja_command = environment.detect_ninja()
        if ninja_command is None:
            raise MesonException('Could not detect Ninja v1.6 or newer')
        elem = NinjaBuildElement(self.all_outputs, 'clean', 'CUSTOM_COMMAND', 'PHONY')
        elem.add_item('COMMAND', [ninja_command, '-t', 'clean'])
        elem.add_item('description', 'Cleaning')
        if 'b_coverage' in self.environment.coredata.base_options and \
           self.environment.coredata.base_options['b_coverage'].value:
            self.generate_gcov_clean(outfile)
            elem.add_dep('clean-gcda')
            elem.add_dep('clean-gcno')
        elem.write(outfile)

        deps = self.get_regen_filelist()
        elem = NinjaBuildElement(self.all_outputs, 'build.ninja', 'REGENERATE_BUILD', deps)
        elem.add_item('pool', 'console')
        elem.write(outfile)

        elem = NinjaBuildElement(self.all_outputs, 'reconfigure', 'REGENERATE_BUILD', 'PHONY')
        elem.add_item('pool', 'console')
        elem.write(outfile)

        elem = NinjaBuildElement(self.all_outputs, deps, 'phony', '')
        elem.write(outfile)
