Add submodule dependency filesHEADmaster

Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec

15 files changed, 3535 insertions, 0 deletions

diff --git a/meson/mesonbuild/compilers/mixins/__init__.py b/meson/mesonbuild/compilers/mixins/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/__init__.py
diff --git a/meson/mesonbuild/compilers/mixins/arm.py b/meson/mesonbuild/compilers/mixins/arm.py
new file mode 100644
index 000000000..4e1898ae7
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/arm.py
@@ -0,0 +1,190 @@
+# Copyright 2012-2020 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.
+
+"""Representations specific to the arm family of compilers."""
+
+import os
+import typing as T
+
+from ... import mesonlib
+from ...linkers import ArmClangDynamicLinker
+from ...mesonlib import OptionKey
+from ..compilers import clike_debug_args
+from .clang import clang_color_args
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+arm_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+arm_optimization_args = {
+    '0': ['-O0'],
+    'g': ['-g'],
+    '1': ['-O1'],
+    '2': [], # Compiler defaults to -O2
+    '3': ['-O3', '-Otime'],
+    's': ['-O3'], # Compiler defaults to -Ospace
+}  # type: T.Dict[str, T.List[str]]
+
+armclang_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+armclang_optimization_args = {
+    '0': [], # Compiler defaults to -O0
+    'g': ['-g'],
+    '1': ['-O1'],
+    '2': ['-O2'],
+    '3': ['-O3'],
+    's': ['-Oz']
+}  # type: T.Dict[str, T.List[str]]
+
+
+class ArmCompiler(Compiler):
+
+    """Functionality that is common to all ARM family compilers."""
+
+    def __init__(self) -> None:
+        if not self.is_cross:
+            raise mesonlib.EnvironmentException('armcc supports only cross-compilation.')
+        self.id = 'arm'
+        default_warn_args = []  # type: T.List[str]
+        self.warn_args = {'0': [],
+                          '1': default_warn_args,
+                          '2': default_warn_args + [],
+                          '3': default_warn_args + []}  # type: T.Dict[str, T.List[str]]
+        # Assembly
+        self.can_compile_suffixes.add('s')
+
+    def get_pic_args(self) -> T.List[str]:
+        # FIXME: Add /ropi, /rwpi, /fpic etc. qualifiers to --apcs
+        return []
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return arm_buildtype_args[buildtype]
+
+    # Override CCompiler.get_always_args
+    def get_always_args(self) -> T.List[str]:
+        return []
+
+    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
+        return ['--depend_target', outtarget, '--depend', outfile, '--depend_single_line']
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        # FIXME: Add required arguments
+        # NOTE from armcc user guide:
+        # "Support for Precompiled Header (PCH) files is deprecated from ARM Compiler 5.05
+        # onwards on all platforms. Note that ARM Compiler on Windows 8 never supported
+        # PCH files."
+        return []
+
+    def get_pch_suffix(self) -> str:
+        # NOTE from armcc user guide:
+        # "Support for Precompiled Header (PCH) files is deprecated from ARM Compiler 5.05
+        # onwards on all platforms. Note that ARM Compiler on Windows 8 never supported
+        # PCH files."
+        return 'pch'
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    def get_coverage_args(self) -> T.List[str]:
+        return []
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return arm_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return clike_debug_args[is_debug]
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:2] == '-I' or i[:2] == '-L':
+                parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))
+
+        return parameter_list
+
+
+class ArmclangCompiler(Compiler):
+
+    def __init__(self) -> None:
+        if not self.is_cross:
+            raise mesonlib.EnvironmentException('armclang supports only cross-compilation.')
+        # Check whether 'armlink' is available in path
+        if not isinstance(self.linker, ArmClangDynamicLinker):
+            raise mesonlib.EnvironmentException(f'Unsupported Linker {self.linker.exelist}, must be armlink')
+        if not mesonlib.version_compare(self.version, '==' + self.linker.version):
+            raise mesonlib.EnvironmentException('armlink version does not match with compiler version')
+        self.id = 'armclang'
+        self.base_options = {
+            OptionKey(o) for o in
+            ['b_pch', 'b_lto', 'b_pgo', 'b_sanitize', 'b_coverage',
+             'b_ndebug', 'b_staticpic', 'b_colorout']}
+        # Assembly
+        self.can_compile_suffixes.add('s')
+
+    def get_pic_args(self) -> T.List[str]:
+        # PIC support is not enabled by default for ARM,
+        # if users want to use it, they need to add the required arguments explicitly
+        return []
+
+    def get_colorout_args(self, colortype: str) -> T.List[str]:
+        return clang_color_args[colortype][:]
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return armclang_buildtype_args[buildtype]
+
+    def get_pch_suffix(self) -> str:
+        return 'gch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        # Workaround for Clang bug http://llvm.org/bugs/show_bug.cgi?id=15136
+        # This flag is internal to Clang (or at least not documented on the man page)
+        # so it might change semantics at any time.
+        return ['-include-pch', os.path.join(pch_dir, self.get_pch_name(header))]
+
+    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
+        return ['-MD', '-MT', outtarget, '-MF', outfile]
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return armclang_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return clike_debug_args[is_debug]
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:2] == '-I' or i[:2] == '-L':
+                parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))
+
+        return parameter_list
diff --git a/meson/mesonbuild/compilers/mixins/c2000.py b/meson/mesonbuild/compilers/mixins/c2000.py
new file mode 100644
index 000000000..287aaa89e
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/c2000.py
@@ -0,0 +1,124 @@
+# Copyright 2012-2019 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.
+
+"""Representations specific to the Texas Instruments C2000 compiler family."""
+
+import os
+import typing as T
+
+from ...mesonlib import EnvironmentException
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+c2000_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+c2000_optimization_args = {
+    '0': ['-O0'],
+    'g': ['-Ooff'],
+    '1': ['-O1'],
+    '2': ['-O2'],
+    '3': ['-O3'],
+    's': ['-04']
+}  # type: T.Dict[str, T.List[str]]
+
+c2000_debug_args = {
+    False: [],
+    True: []
+}  # type: T.Dict[bool, T.List[str]]
+
+
+class C2000Compiler(Compiler):
+
+    def __init__(self) -> None:
+        if not self.is_cross:
+            raise EnvironmentException('c2000 supports only cross-compilation.')
+        self.id = 'c2000'
+        # Assembly
+        self.can_compile_suffixes.add('asm')
+        default_warn_args = []  # type: T.List[str]
+        self.warn_args = {'0': [],
+                          '1': default_warn_args,
+                          '2': default_warn_args + [],
+                          '3': default_warn_args + []}  # type: T.Dict[str, T.List[str]]
+
+    def get_pic_args(self) -> T.List[str]:
+        # PIC support is not enabled by default for c2000,
+        # if users want to use it, they need to add the required arguments explicitly
+        return []
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return c2000_buildtype_args[buildtype]
+
+    def get_pch_suffix(self) -> str:
+        return 'pch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        return []
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    def get_coverage_args(self) -> T.List[str]:
+        return []
+
+    def get_no_stdinc_args(self) -> T.List[str]:
+        return []
+
+    def get_no_stdlib_link_args(self) -> T.List[str]:
+        return []
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return c2000_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return c2000_debug_args[is_debug]
+
+    @classmethod
+    def unix_args_to_native(cls, args: T.List[str]) -> T.List[str]:
+        result = []
+        for i in args:
+            if i.startswith('-D'):
+                i = '-define=' + i[2:]
+            if i.startswith('-I'):
+                i = '-include=' + i[2:]
+            if i.startswith('-Wl,-rpath='):
+                continue
+            elif i == '--print-search-dirs':
+                continue
+            elif i.startswith('-L'):
+                continue
+            result.append(i)
+        return result
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:9] == '-include=':
+                parameter_list[idx] = i[:9] + os.path.normpath(os.path.join(build_dir, i[9:]))
+
+        return parameter_list
diff --git a/meson/mesonbuild/compilers/mixins/ccrx.py b/meson/mesonbuild/compilers/mixins/ccrx.py
new file mode 100644
index 000000000..eba4c455f
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/ccrx.py
@@ -0,0 +1,130 @@
+# Copyright 2012-2019 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.
+
+"""Representations specific to the Renesas CC-RX compiler family."""
+
+import os
+import typing as T
+
+from ...mesonlib import EnvironmentException
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+ccrx_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+ccrx_optimization_args = {
+    '0': ['-optimize=0'],
+    'g': ['-optimize=0'],
+    '1': ['-optimize=1'],
+    '2': ['-optimize=2'],
+    '3': ['-optimize=max'],
+    's': ['-optimize=2', '-size']
+}  # type: T.Dict[str, T.List[str]]
+
+ccrx_debug_args = {
+    False: [],
+    True: ['-debug']
+}  # type: T.Dict[bool, T.List[str]]
+
+
+class CcrxCompiler(Compiler):
+
+    if T.TYPE_CHECKING:
+        is_cross = True
+        can_compile_suffixes = set()  # type: T.Set[str]
+
+    def __init__(self) -> None:
+        if not self.is_cross:
+            raise EnvironmentException('ccrx supports only cross-compilation.')
+        self.id = 'ccrx'
+        # Assembly
+        self.can_compile_suffixes.add('src')
+        default_warn_args = []  # type: T.List[str]
+        self.warn_args = {'0': [],
+                          '1': default_warn_args,
+                          '2': default_warn_args + [],
+                          '3': default_warn_args + []}  # type: T.Dict[str, T.List[str]]
+
+    def get_pic_args(self) -> T.List[str]:
+        # PIC support is not enabled by default for CCRX,
+        # if users want to use it, they need to add the required arguments explicitly
+        return []
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return ccrx_buildtype_args[buildtype]
+
+    def get_pch_suffix(self) -> str:
+        return 'pch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        return []
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    def get_coverage_args(self) -> T.List[str]:
+        return []
+
+    def get_no_stdinc_args(self) -> T.List[str]:
+        return []
+
+    def get_no_stdlib_link_args(self) -> T.List[str]:
+        return []
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return ccrx_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return ccrx_debug_args[is_debug]
+
+    @classmethod
+    def unix_args_to_native(cls, args: T.List[str]) -> T.List[str]:
+        result = []
+        for i in args:
+            if i.startswith('-D'):
+                i = '-define=' + i[2:]
+            if i.startswith('-I'):
+                i = '-include=' + i[2:]
+            if i.startswith('-Wl,-rpath='):
+                continue
+            elif i == '--print-search-dirs':
+                continue
+            elif i.startswith('-L'):
+                continue
+            elif not i.startswith('-lib=') and i.endswith(('.a', '.lib')):
+                i = '-lib=' + i
+            result.append(i)
+        return result
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:9] == '-include=':
+                parameter_list[idx] = i[:9] + os.path.normpath(os.path.join(build_dir, i[9:]))
+
+        return parameter_list
diff --git a/meson/mesonbuild/compilers/mixins/clang.py b/meson/mesonbuild/compilers/mixins/clang.py
new file mode 100644
index 000000000..f7e94928c
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/clang.py
@@ -0,0 +1,162 @@
+# Copyright 2019 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.
+
+"""Abstractions for the LLVM/Clang compiler family."""
+
+import os
+import shutil
+import typing as T
+
+from ... import mesonlib
+from ...linkers import AppleDynamicLinker, ClangClDynamicLinker, LLVMDynamicLinker, GnuGoldDynamicLinker
+from ...mesonlib import OptionKey
+from ..compilers import CompileCheckMode
+from .gnu import GnuLikeCompiler
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...dependencies import Dependency  # noqa: F401
+
+clang_color_args = {
+    'auto': ['-fcolor-diagnostics'],
+    'always': ['-fcolor-diagnostics'],
+    'never': ['-fno-color-diagnostics'],
+}  # type: T.Dict[str, T.List[str]]
+
+clang_optimization_args = {
+    '0': ['-O0'],
+    'g': ['-Og'],
+    '1': ['-O1'],
+    '2': ['-O2'],
+    '3': ['-O3'],
+    's': ['-Os'],
+}  # type: T.Dict[str, T.List[str]]
+
+class ClangCompiler(GnuLikeCompiler):
+
+    def __init__(self, defines: T.Optional[T.Dict[str, str]]):
+        super().__init__()
+        self.id = 'clang'
+        self.defines = defines or {}
+        self.base_options.update(
+            {OptionKey('b_colorout'), OptionKey('b_lto_threads'), OptionKey('b_lto_mode')})
+
+        # TODO: this really should be part of the linker base_options, but
+        # linkers don't have base_options.
+        if isinstance(self.linker, AppleDynamicLinker):
+            self.base_options.add(OptionKey('b_bitcode'))
+        # All Clang backends can also do LLVM IR
+        self.can_compile_suffixes.add('ll')
+
+    def get_colorout_args(self, colortype: str) -> T.List[str]:
+        return clang_color_args[colortype][:]
+
+    def has_builtin_define(self, define: str) -> bool:
+        return define in self.defines
+
+    def get_builtin_define(self, define: str) -> T.Optional[str]:
+        return self.defines.get(define)
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return clang_optimization_args[optimization_level]
+
+    def get_pch_suffix(self) -> str:
+        return 'pch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        # Workaround for Clang bug http://llvm.org/bugs/show_bug.cgi?id=15136
+        # This flag is internal to Clang (or at least not documented on the man page)
+        # so it might change semantics at any time.
+        return ['-include-pch', os.path.join(pch_dir, self.get_pch_name(header))]
+
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
+        # Clang is different than GCC, it will return True when a symbol isn't
+        # defined in a header. Specifically this seems ot have something to do
+        # with functions that may be in a header on some systems, but not all of
+        # them. `strlcat` specifically with can trigger this.
+        myargs: T.List[str] = ['-Werror=implicit-function-declaration']
+        if mode is CompileCheckMode.COMPILE:
+            myargs.extend(['-Werror=unknown-warning-option', '-Werror=unused-command-line-argument'])
+            if mesonlib.version_compare(self.version, '>=3.6.0'):
+                myargs.append('-Werror=ignored-optimization-argument')
+        return super().get_compiler_check_args(mode) + myargs
+
+    def has_function(self, funcname: str, prefix: str, env: 'Environment', *,
+                     extra_args: T.Optional[T.List[str]] = None,
+                     dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
+        if extra_args is None:
+            extra_args = []
+        # Starting with XCode 8, we need to pass this to force linker
+        # visibility to obey OS X/iOS/tvOS minimum version targets with
+        # -mmacosx-version-min, -miphoneos-version-min, -mtvos-version-min etc.
+        # https://github.com/Homebrew/homebrew-core/issues/3727
+        # TODO: this really should be communicated by the linker
+        if isinstance(self.linker, AppleDynamicLinker) and mesonlib.version_compare(self.version, '>=8.0'):
+            extra_args.append('-Wl,-no_weak_imports')
+        return super().has_function(funcname, prefix, env, extra_args=extra_args,
+                                   dependencies=dependencies)
+
+    def openmp_flags(self) -> T.List[str]:
+        if mesonlib.version_compare(self.version, '>=3.8.0'):
+            return ['-fopenmp']
+        elif mesonlib.version_compare(self.version, '>=3.7.0'):
+            return ['-fopenmp=libomp']
+        else:
+            # Shouldn't work, but it'll be checked explicitly in the OpenMP dependency.
+            return []
+
+    @classmethod
+    def use_linker_args(cls, linker: str) -> T.List[str]:
+        # Clang additionally can use a linker specified as a path, which GCC
+        # (and other gcc-like compilers) cannot. This is becuse clang (being
+        # llvm based) is retargetable, while GCC is not.
+        #
+
+        # qcld: Qualcomm Snapdragon linker, based on LLVM
+        if linker == 'qcld':
+            return  ['-fuse-ld=qcld']
+
+        if shutil.which(linker):
+            if not shutil.which(linker):
+                raise mesonlib.MesonException(
+                    f'Cannot find linker {linker}.')
+            return [f'-fuse-ld={linker}']
+        return super().use_linker_args(linker)
+
+    def get_has_func_attribute_extra_args(self, name: str) -> T.List[str]:
+        # Clang only warns about unknown or ignored attributes, so force an
+        # error.
+        return ['-Werror=attributes']
+
+    def get_coverage_link_args(self) -> T.List[str]:
+        return ['--coverage']
+
+    def get_lto_compile_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
+        args: T.List[str] = []
+        if mode == 'thin':
+            # Thin LTO requires the use of gold, lld, ld64, or lld-link
+            if not isinstance(self.linker, (AppleDynamicLinker, ClangClDynamicLinker, LLVMDynamicLinker, GnuGoldDynamicLinker)):
+                raise mesonlib.MesonException(f"LLVM's thinLTO only works with gnu gold, lld, lld-link, and ld64, not {self.linker.id}")
+            args.append(f'-flto={mode}')
+        else:
+            assert mode == 'default', 'someone forgot to wire something up'
+            args.extend(super().get_lto_compile_args(threads=threads))
+        return args
+
+    def get_lto_link_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
+        args = self.get_lto_compile_args(threads=threads, mode=mode)
+        # In clang -flto=0 means auto
+        if threads >= 0:
+            args.append(f'-flto-jobs={threads}')
+        return args
diff --git a/meson/mesonbuild/compilers/mixins/clike.py b/meson/mesonbuild/compilers/mixins/clike.py
new file mode 100644
index 000000000..09ad837b1
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/clike.py
@@ -0,0 +1,1267 @@
+# Copyright 2012-2017 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.
+
+
+"""Mixin classes to be shared between C and C++ compilers.
+
+Without this we'll end up with awful diamond inherintance problems. The goal
+of this is to have mixin's, which are classes that are designed *not* to be
+standalone, they only work through inheritance.
+"""
+
+import collections
+import functools
+import glob
+import itertools
+import os
+import re
+import subprocess
+import typing as T
+from pathlib import Path
+
+from ... import arglist
+from ... import mesonlib
+from ... import mlog
+from ...linkers import GnuLikeDynamicLinkerMixin, SolarisDynamicLinker, CompCertDynamicLinker
+from ...mesonlib import LibType
+from ...coredata import OptionKey
+from .. import compilers
+from ..compilers import CompileCheckMode
+from .visualstudio import VisualStudioLikeCompiler
+
+if T.TYPE_CHECKING:
+    from ...dependencies import Dependency
+    from ..._typing import ImmutableListProtocol
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+    from ...programs import ExternalProgram
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+GROUP_FLAGS = re.compile(r'''\.so (?:\.[0-9]+)? (?:\.[0-9]+)? (?:\.[0-9]+)?$ |
+                             ^(?:-Wl,)?-l |
+                             \.a$''', re.X)
+
+class CLikeCompilerArgs(arglist.CompilerArgs):
+    prepend_prefixes = ('-I', '-L')
+    dedup2_prefixes = ('-I', '-isystem', '-L', '-D', '-U')
+
+    # NOTE: not thorough. A list of potential corner cases can be found in
+    # https://github.com/mesonbuild/meson/pull/4593#pullrequestreview-182016038
+    dedup1_prefixes = ('-l', '-Wl,-l', '-Wl,--export-dynamic')
+    dedup1_suffixes = ('.lib', '.dll', '.so', '.dylib', '.a')
+    dedup1_args = ('-c', '-S', '-E', '-pipe', '-pthread')
+
+    def to_native(self, copy: bool = False) -> T.List[str]:
+        # This seems to be allowed, but could never work?
+        assert isinstance(self.compiler, compilers.Compiler), 'How did you get here'
+
+        # Check if we need to add --start/end-group for circular dependencies
+        # between static libraries, and for recursively searching for symbols
+        # needed by static libraries that are provided by object files or
+        # shared libraries.
+        self.flush_pre_post()
+        if copy:
+            new = self.copy()
+        else:
+            new = self
+        # This covers all ld.bfd, ld.gold, ld.gold, and xild on Linux, which
+        # all act like (or are) gnu ld
+        # TODO: this could probably be added to the DynamicLinker instead
+        if isinstance(self.compiler.linker, (GnuLikeDynamicLinkerMixin, SolarisDynamicLinker, CompCertDynamicLinker)):
+            group_start = -1
+            group_end = -1
+            for i, each in enumerate(new):
+                if not GROUP_FLAGS.search(each):
+                    continue
+                group_end = i
+                if group_start < 0:
+                    # First occurrence of a library
+                    group_start = i
+            if group_start >= 0:
+                # Last occurrence of a library
+                new.insert(group_end + 1, '-Wl,--end-group')
+                new.insert(group_start, '-Wl,--start-group')
+        # Remove system/default include paths added with -isystem
+        default_dirs = self.compiler.get_default_include_dirs()
+        if default_dirs:
+            bad_idx_list = []  # type: T.List[int]
+            for i, each in enumerate(new):
+                if not each.startswith('-isystem'):
+                    continue
+
+                # Remove the -isystem and the path if the path is a default path
+                if (each == '-isystem' and
+                        i < (len(new) - 1) and
+                        new[i + 1] in default_dirs):
+                    bad_idx_list += [i, i + 1]
+                elif each.startswith('-isystem=') and each[9:] in default_dirs:
+                    bad_idx_list += [i]
+                elif each[8:] in default_dirs:
+                    bad_idx_list += [i]
+            for i in reversed(bad_idx_list):
+                new.pop(i)
+        return self.compiler.unix_args_to_native(new._container)
+
+    def __repr__(self) -> str:
+        self.flush_pre_post()
+        return f'CLikeCompilerArgs({self.compiler!r}, {self._container!r})'
+
+
+class CLikeCompiler(Compiler):
+
+    """Shared bits for the C and CPP Compilers."""
+
+    if T.TYPE_CHECKING:
+        warn_args = {}  # type: T.Dict[str, T.List[str]]
+
+    # TODO: Replace this manual cache with functools.lru_cache
+    find_library_cache = {}    # type: T.Dict[T.Tuple[T.Tuple[str, ...], str, T.Tuple[str, ...], str, LibType], T.Optional[T.List[str]]]
+    find_framework_cache = {}  # type: T.Dict[T.Tuple[T.Tuple[str, ...], str, T.Tuple[str, ...], bool], T.Optional[T.List[str]]]
+    internal_libs = arglist.UNIXY_COMPILER_INTERNAL_LIBS
+
+    def __init__(self, exe_wrapper: T.Optional['ExternalProgram'] = None):
+        # If a child ObjC or CPP class has already set it, don't set it ourselves
+        self.can_compile_suffixes.add('h')
+        # If the exe wrapper was not found, pretend it wasn't set so that the
+        # sanity check is skipped and compiler checks use fallbacks.
+        if not exe_wrapper or not exe_wrapper.found() or not exe_wrapper.get_command():
+            self.exe_wrapper = None
+        else:
+            self.exe_wrapper = exe_wrapper
+
+    def compiler_args(self, args: T.Optional[T.Iterable[str]] = None) -> CLikeCompilerArgs:
+        # This is correct, mypy just doesn't understand co-operative inheritance
+        return CLikeCompilerArgs(self, args)
+
+    def needs_static_linker(self) -> bool:
+        return True # When compiling static libraries, so yes.
+
+    def get_always_args(self) -> T.List[str]:
+        '''
+        Args that are always-on for all C compilers other than MSVC
+        '''
+        return self.get_largefile_args()
+
+    def get_no_stdinc_args(self) -> T.List[str]:
+        return ['-nostdinc']
+
+    def get_no_stdlib_link_args(self) -> T.List[str]:
+        return ['-nostdlib']
+
+    def get_warn_args(self, level: str) -> T.List[str]:
+        # TODO: this should be an enum
+        return self.warn_args[level]
+
+    def get_no_warn_args(self) -> T.List[str]:
+        # Almost every compiler uses this for disabling warnings
+        return ['-w']
+
+    def get_depfile_suffix(self) -> str:
+        return 'd'
+
+    def get_exelist(self) -> T.List[str]:
+        return self.exelist.copy()
+
+    def get_preprocess_only_args(self) -> T.List[str]:
+        return ['-E', '-P']
+
+    def get_compile_only_args(self) -> T.List[str]:
+        return ['-c']
+
+    def get_no_optimization_args(self) -> T.List[str]:
+        return ['-O0']
+
+    def get_output_args(self, target: str) -> T.List[str]:
+        return ['-o', target]
+
+    def get_werror_args(self) -> T.List[str]:
+        return ['-Werror']
+
+    def get_include_args(self, path: str, is_system: bool) -> T.List[str]:
+        if path == '':
+            path = '.'
+        if is_system:
+            return ['-isystem', path]
+        return ['-I' + path]
+
+    def get_compiler_dirs(self, env: 'Environment', name: str) -> T.List[str]:
+        '''
+        Get dirs from the compiler, either `libraries:` or `programs:`
+        '''
+        return []
+
+    @functools.lru_cache()
+    def _get_library_dirs(self, env: 'Environment',
+                          elf_class: T.Optional[int] = None) -> 'ImmutableListProtocol[str]':
+        # TODO: replace elf_class with enum
+        dirs = self.get_compiler_dirs(env, 'libraries')
+        if elf_class is None or elf_class == 0:
+            return dirs
+
+        # if we do have an elf class for 32-bit or 64-bit, we want to check that
+        # the directory in question contains libraries of the appropriate class. Since
+        # system directories aren't mixed, we only need to check one file for each
+        # directory and go by that. If we can't check the file for some reason, assume
+        # the compiler knows what it's doing, and accept the directory anyway.
+        retval = []
+        for d in dirs:
+            files = [f for f in os.listdir(d) if f.endswith('.so') and os.path.isfile(os.path.join(d, f))]
+            # if no files, accept directory and move on
+            if not files:
+                retval.append(d)
+                continue
+
+            for f in files:
+                file_to_check = os.path.join(d, f)
+                try:
+                    with open(file_to_check, 'rb') as fd:
+                        header = fd.read(5)
+                        # if file is not an ELF file, it's weird, but accept dir
+                        # if it is elf, and the class matches, accept dir
+                        if header[1:4] != b'ELF' or int(header[4]) == elf_class:
+                            retval.append(d)
+                        # at this point, it's an ELF file which doesn't match the
+                        # appropriate elf_class, so skip this one
+                    # stop scanning after the first successful read
+                    break
+                except OSError:
+                    # Skip the file if we can't read it
+                    pass
+
+        return retval
+
+    def get_library_dirs(self, env: 'Environment',
+                         elf_class: T.Optional[int] = None) -> T.List[str]:
+        """Wrap the lru_cache so that we return a new copy and don't allow
+        mutation of the cached value.
+        """
+        return self._get_library_dirs(env, elf_class).copy()
+
+    @functools.lru_cache()
+    def _get_program_dirs(self, env: 'Environment') -> 'ImmutableListProtocol[str]':
+        '''
+        Programs used by the compiler. Also where toolchain DLLs such as
+        libstdc++-6.dll are found with MinGW.
+        '''
+        return self.get_compiler_dirs(env, 'programs')
+
+    def get_program_dirs(self, env: 'Environment') -> T.List[str]:
+        return self._get_program_dirs(env).copy()
+
+    def get_pic_args(self) -> T.List[str]:
+        return ['-fPIC']
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        return ['-include', os.path.basename(header)]
+
+    def get_pch_name(self, header_name: str) -> str:
+        return os.path.basename(header_name) + '.' + self.get_pch_suffix()
+
+    def get_default_include_dirs(self) -> T.List[str]:
+        return []
+
+    def gen_export_dynamic_link_args(self, env: 'Environment') -> T.List[str]:
+        return self.linker.export_dynamic_args(env)
+
+    def gen_import_library_args(self, implibname: str) -> T.List[str]:
+        return self.linker.import_library_args(implibname)
+
+    def _sanity_check_impl(self, work_dir: str, environment: 'Environment',
+                         sname: str, code: str) -> None:
+        mlog.debug('Sanity testing ' + self.get_display_language() + ' compiler:', ' '.join(self.exelist))
+        mlog.debug(f'Is cross compiler: {self.is_cross!s}.')
+
+        source_name = os.path.join(work_dir, sname)
+        binname = sname.rsplit('.', 1)[0]
+        mode = CompileCheckMode.LINK
+        if self.is_cross:
+            binname += '_cross'
+            if self.exe_wrapper is None:
+                # Linking cross built apps is painful. You can't really
+                # tell if you should use -nostdlib or not and for example
+                # on OSX the compiler binary is the same but you need
+                # a ton of compiler flags to differentiate between
+                # arm and x86_64. So just compile.
+                mode = CompileCheckMode.COMPILE
+        cargs, largs = self._get_basic_compiler_args(environment, mode)
+        extra_flags = cargs + self.linker_to_compiler_args(largs)
+
+        # Is a valid executable output for all toolchains and platforms
+        binname += '.exe'
+        # Write binary check source
+        binary_name = os.path.join(work_dir, binname)
+        with open(source_name, 'w', encoding='utf-8') as ofile:
+            ofile.write(code)
+        # Compile sanity check
+        # NOTE: extra_flags must be added at the end. On MSVC, it might contain a '/link' argument
+        # after which all further arguments will be passed directly to the linker
+        cmdlist = self.exelist + [sname] + self.get_output_args(binname) + extra_flags
+        pc, stdo, stde = mesonlib.Popen_safe(cmdlist, cwd=work_dir)
+        mlog.debug('Sanity check compiler command line:', ' '.join(cmdlist))
+        mlog.debug('Sanity check compile stdout:')
+        mlog.debug(stdo)
+        mlog.debug('-----\nSanity check compile stderr:')
+        mlog.debug(stde)
+        mlog.debug('-----')
+        if pc.returncode != 0:
+            raise mesonlib.EnvironmentException(f'Compiler {self.name_string()} can not compile programs.')
+        # Run sanity check
+        if self.is_cross:
+            if self.exe_wrapper is None:
+                # Can't check if the binaries run so we have to assume they do
+                return
+            cmdlist = self.exe_wrapper.get_command() + [binary_name]
+        else:
+            cmdlist = [binary_name]
+        mlog.debug('Running test binary command: ' + ' '.join(cmdlist))
+        try:
+            pe = subprocess.Popen(cmdlist)
+        except Exception as e:
+            raise mesonlib.EnvironmentException(f'Could not invoke sanity test executable: {e!s}.')
+        pe.wait()
+        if pe.returncode != 0:
+            raise mesonlib.EnvironmentException(f'Executables created by {self.language} compiler {self.name_string()} are not runnable.')
+
+    def sanity_check(self, work_dir: str, environment: 'Environment') -> None:
+        code = 'int main(void) { int class=0; return class; }\n'
+        return self._sanity_check_impl(work_dir, environment, 'sanitycheckc.c', code)
+
+    def check_header(self, hname: str, prefix: str, env: 'Environment', *,
+                     extra_args: T.Optional[T.List[str]] = None,
+                     dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
+        code = f'''{prefix}
+        #include <{hname}>'''
+        return self.compiles(code, env, extra_args=extra_args,
+                             dependencies=dependencies)
+
+    def has_header(self, hname: str, prefix: str, env: 'Environment', *,
+                   extra_args: T.Optional[T.List[str]] = None,
+                   dependencies: T.Optional[T.List['Dependency']] = None,
+                   disable_cache: bool = False) -> T.Tuple[bool, bool]:
+        code = f'''{prefix}
+        #ifdef __has_include
+         #if !__has_include("{hname}")
+          #error "Header '{hname}' could not be found"
+         #endif
+        #else
+         #include <{hname}>
+        #endif'''
+        return self.compiles(code, env, extra_args=extra_args,
+                             dependencies=dependencies, mode='preprocess', disable_cache=disable_cache)
+
+    def has_header_symbol(self, hname: str, symbol: str, prefix: str,
+                          env: 'Environment', *,
+                          extra_args: T.Optional[T.List[str]] = None,
+                          dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
+        t = f'''{prefix}
+        #include <{hname}>
+        int main(void) {{
+            /* If it's not defined as a macro, try to use as a symbol */
+            #ifndef {symbol}
+                {symbol};
+            #endif
+            return 0;
+        }}'''
+        return self.compiles(t, env, extra_args=extra_args,
+                             dependencies=dependencies)
+
+    def _get_basic_compiler_args(self, env: 'Environment', mode: CompileCheckMode) -> T.Tuple[T.List[str], T.List[str]]:
+        cargs = []  # type: T.List[str]
+        largs = []  # type: T.List[str]
+        if mode is CompileCheckMode.LINK:
+            # Sometimes we need to manually select the CRT to use with MSVC.
+            # One example is when trying to do a compiler check that involves
+            # linking with static libraries since MSVC won't select a CRT for
+            # us in that case and will error out asking us to pick one.
+            try:
+                crt_val = env.coredata.options[OptionKey('b_vscrt')].value
+                buildtype = env.coredata.options[OptionKey('buildtype')].value
+                cargs += self.get_crt_compile_args(crt_val, buildtype)
+            except (KeyError, AttributeError):
+                pass
+
+        # Add CFLAGS/CXXFLAGS/OBJCFLAGS/OBJCXXFLAGS and CPPFLAGS from the env
+        sys_args = env.coredata.get_external_args(self.for_machine, self.language)
+        if isinstance(sys_args, str):
+            sys_args = [sys_args]
+        # Apparently it is a thing to inject linker flags both
+        # via CFLAGS _and_ LDFLAGS, even though the former are
+        # also used during linking. These flags can break
+        # argument checks. Thanks, Autotools.
+        cleaned_sys_args = self.remove_linkerlike_args(sys_args)
+        cargs += cleaned_sys_args
+
+        if mode is CompileCheckMode.LINK:
+            ld_value = env.lookup_binary_entry(self.for_machine, self.language + '_ld')
+            if ld_value is not None:
+                largs += self.use_linker_args(ld_value[0])
+
+            # Add LDFLAGS from the env
+            sys_ld_args = env.coredata.get_external_link_args(self.for_machine, self.language)
+            # CFLAGS and CXXFLAGS go to both linking and compiling, but we want them
+            # to only appear on the command line once. Remove dupes.
+            largs += [x for x in sys_ld_args if x not in sys_args]
+
+        cargs += self.get_compiler_args_for_mode(mode)
+        return cargs, largs
+
+    def build_wrapper_args(self, env: 'Environment',
+                           extra_args: T.Union[None, arglist.CompilerArgs, T.List[str]],
+                           dependencies: T.Optional[T.List['Dependency']],
+                           mode: CompileCheckMode = CompileCheckMode.COMPILE) -> arglist.CompilerArgs:
+        # TODO: the caller should handle the listfing of these arguments
+        if extra_args is None:
+            extra_args = []
+        else:
+            # TODO: we want to do this in the caller
+            extra_args = mesonlib.listify(extra_args)
+        extra_args = mesonlib.listify([e(mode.value) if callable(e) else e for e in extra_args])
+
+        if dependencies is None:
+            dependencies = []
+        elif not isinstance(dependencies, collections.abc.Iterable):
+            # TODO: we want to ensure the front end does the listifing here
+            dependencies = [dependencies]  # type: ignore
+        # Collect compiler arguments
+        cargs = self.compiler_args()  # type: arglist.CompilerArgs
+        largs = []  # type: T.List[str]
+        for d in dependencies:
+            # Add compile flags needed by dependencies
+            cargs += d.get_compile_args()
+            if mode is CompileCheckMode.LINK:
+                # Add link flags needed to find dependencies
+                largs += d.get_link_args()
+
+        ca, la = self._get_basic_compiler_args(env, mode)
+        cargs += ca
+        largs += la
+
+        cargs += self.get_compiler_check_args(mode)
+
+        # on MSVC compiler and linker flags must be separated by the "/link" argument
+        # at this point, the '/link' argument may already be part of extra_args, otherwise, it is added here
+        if self.linker_to_compiler_args([]) == ['/link'] and largs != [] and not ('/link' in extra_args):
+            extra_args += ['/link']
+
+        args = cargs + extra_args + largs
+        return args
+
+    def run(self, code: str, env: 'Environment', *,
+            extra_args: T.Optional[T.List[str]] = None,
+            dependencies: T.Optional[T.List['Dependency']] = None) -> compilers.RunResult:
+        need_exe_wrapper = env.need_exe_wrapper(self.for_machine)
+        if need_exe_wrapper and self.exe_wrapper is None:
+            raise compilers.CrossNoRunException('Can not run test applications in this cross environment.')
+        with self._build_wrapper(code, env, extra_args, dependencies, mode='link', want_output=True) as p:
+            if p.returncode != 0:
+                mlog.debug(f'Could not compile test file {p.input_name}: {p.returncode}\n')
+                return compilers.RunResult(False)
+            if need_exe_wrapper:
+                cmdlist = self.exe_wrapper.get_command() + [p.output_name]
+            else:
+                cmdlist = [p.output_name]
+            try:
+                pe, so, se = mesonlib.Popen_safe(cmdlist)
+            except Exception as e:
+                mlog.debug(f'Could not run: {cmdlist} (error: {e})\n')
+                return compilers.RunResult(False)
+
+        mlog.debug('Program stdout:\n')
+        mlog.debug(so)
+        mlog.debug('Program stderr:\n')
+        mlog.debug(se)
+        return compilers.RunResult(True, pe.returncode, so, se)
+
+    def _compile_int(self, expression: str, prefix: str, env: 'Environment',
+                     extra_args: T.Optional[T.List[str]],
+                     dependencies: T.Optional[T.List['Dependency']]) -> bool:
+        t = f'''#include <stdio.h>
+        {prefix}
+        int main(void) {{ static int a[1-2*!({expression})]; a[0]=0; return 0; }}'''
+        return self.compiles(t, env, extra_args=extra_args,
+                             dependencies=dependencies)[0]
+
+    def cross_compute_int(self, expression: str, low: T.Optional[int], high: T.Optional[int],
+                          guess: T.Optional[int], prefix: str, env: 'Environment',
+                          extra_args: T.Optional[T.List[str]] = None,
+                          dependencies: T.Optional[T.List['Dependency']] = None) -> int:
+        # Try user's guess first
+        if isinstance(guess, int):
+            if self._compile_int(f'{expression} == {guess}', prefix, env, extra_args, dependencies):
+                return guess
+
+        # If no bounds are given, compute them in the limit of int32
+        maxint = 0x7fffffff
+        minint = -0x80000000
+        if not isinstance(low, int) or not isinstance(high, int):
+            if self._compile_int(f'{expression} >= 0', prefix, env, extra_args, dependencies):
+                low = cur = 0
+                while self._compile_int(f'{expression} > {cur}', prefix, env, extra_args, dependencies):
+                    low = cur + 1
+                    if low > maxint:
+                        raise mesonlib.EnvironmentException('Cross-compile check overflowed')
+                    cur = cur * 2 + 1
+                    if cur > maxint:
+                        cur = maxint
+                high = cur
+            else:
+                high = cur = -1
+                while self._compile_int(f'{expression} < {cur}', prefix, env, extra_args, dependencies):
+                    high = cur - 1
+                    if high < minint:
+                        raise mesonlib.EnvironmentException('Cross-compile check overflowed')
+                    cur = cur * 2
+                    if cur < minint:
+                        cur = minint
+                low = cur
+        else:
+            # Sanity check limits given by user
+            if high < low:
+                raise mesonlib.EnvironmentException('high limit smaller than low limit')
+            condition = f'{expression} <= {high} && {expression} >= {low}'
+            if not self._compile_int(condition, prefix, env, extra_args, dependencies):
+                raise mesonlib.EnvironmentException('Value out of given range')
+
+        # Binary search
+        while low != high:
+            cur = low + int((high - low) / 2)
+            if self._compile_int(f'{expression} <= {cur}', prefix, env, extra_args, dependencies):
+                high = cur
+            else:
+                low = cur + 1
+
+        return low
+
+    def compute_int(self, expression: str, low: T.Optional[int], high: T.Optional[int],
+                    guess: T.Optional[int], prefix: str, env: 'Environment', *,
+                    extra_args: T.Optional[T.List[str]] = None,
+                    dependencies: T.Optional[T.List['Dependency']] = None) -> int:
+        if extra_args is None:
+            extra_args = []
+        if self.is_cross:
+            return self.cross_compute_int(expression, low, high, guess, prefix, env, extra_args, dependencies)
+        t = f'''#include<stdio.h>
+        {prefix}
+        int main(void) {{
+            printf("%ld\\n", (long)({expression}));
+            return 0;
+        }};'''
+        res = self.run(t, env, extra_args=extra_args,
+                       dependencies=dependencies)
+        if not res.compiled:
+            return -1
+        if res.returncode != 0:
+            raise mesonlib.EnvironmentException('Could not run compute_int test binary.')
+        return int(res.stdout)
+
+    def cross_sizeof(self, typename: str, prefix: str, env: 'Environment', *,
+                     extra_args: T.Optional[T.List[str]] = None,
+                     dependencies: T.Optional[T.List['Dependency']] = None) -> int:
+        if extra_args is None:
+            extra_args = []
+        t = f'''#include <stdio.h>
+        {prefix}
+        int main(void) {{
+            {typename} something;
+            return 0;
+        }}'''
+        if not self.compiles(t, env, extra_args=extra_args,
+                             dependencies=dependencies)[0]:
+            return -1
+        return self.cross_compute_int(f'sizeof({typename})', None, None, None, prefix, env, extra_args, dependencies)
+
+    def sizeof(self, typename: str, prefix: str, env: 'Environment', *,
+               extra_args: T.Optional[T.List[str]] = None,
+               dependencies: T.Optional[T.List['Dependency']] = None) -> int:
+        if extra_args is None:
+            extra_args = []
+        if self.is_cross:
+            return self.cross_sizeof(typename, prefix, env, extra_args=extra_args,
+                                     dependencies=dependencies)
+        t = f'''#include<stdio.h>
+        {prefix}
+        int main(void) {{
+            printf("%ld\\n", (long)(sizeof({typename})));
+            return 0;
+        }};'''
+        res = self.run(t, env, extra_args=extra_args,
+                       dependencies=dependencies)
+        if not res.compiled:
+            return -1
+        if res.returncode != 0:
+            raise mesonlib.EnvironmentException('Could not run sizeof test binary.')
+        return int(res.stdout)
+
+    def cross_alignment(self, typename: str, prefix: str, env: 'Environment', *,
+                        extra_args: T.Optional[T.List[str]] = None,
+                        dependencies: T.Optional[T.List['Dependency']] = None) -> int:
+        if extra_args is None:
+            extra_args = []
+        t = f'''#include <stdio.h>
+        {prefix}
+        int main(void) {{
+            {typename} something;
+            return 0;
+        }}'''
+        if not self.compiles(t, env, extra_args=extra_args,
+                             dependencies=dependencies)[0]:
+            return -1
+        t = f'''#include <stddef.h>
+        {prefix}
+        struct tmp {{
+            char c;
+            {typename} target;
+        }};'''
+        return self.cross_compute_int('offsetof(struct tmp, target)', None, None, None, t, env, extra_args, dependencies)
+
+    def alignment(self, typename: str, prefix: str, env: 'Environment', *,
+                  extra_args: T.Optional[T.List[str]] = None,
+                  dependencies: T.Optional[T.List['Dependency']] = None) -> int:
+        if extra_args is None:
+            extra_args = []
+        if self.is_cross:
+            return self.cross_alignment(typename, prefix, env, extra_args=extra_args,
+                                        dependencies=dependencies)
+        t = f'''#include <stdio.h>
+        #include <stddef.h>
+        {prefix}
+        struct tmp {{
+            char c;
+            {typename} target;
+        }};
+        int main(void) {{
+            printf("%d", (int)offsetof(struct tmp, target));
+            return 0;
+        }}'''
+        res = self.run(t, env, extra_args=extra_args,
+                       dependencies=dependencies)
+        if not res.compiled:
+            raise mesonlib.EnvironmentException('Could not compile alignment test.')
+        if res.returncode != 0:
+            raise mesonlib.EnvironmentException('Could not run alignment test binary.')
+        align = int(res.stdout)
+        if align == 0:
+            raise mesonlib.EnvironmentException(f'Could not determine alignment of {typename}. Sorry. You might want to file a bug.')
+        return align
+
+    def get_define(self, dname: str, prefix: str, env: 'Environment',
+                   extra_args: T.Optional[T.List[str]],
+                   dependencies: T.Optional[T.List['Dependency']],
+                   disable_cache: bool = False) -> T.Tuple[str, bool]:
+        delim = '"MESON_GET_DEFINE_DELIMITER"'
+        code = f'''
+        {prefix}
+        #ifndef {dname}
+        # define {dname}
+        #endif
+        {delim}\n{dname}'''
+        args = self.build_wrapper_args(env, extra_args, dependencies,
+                                             mode=CompileCheckMode.PREPROCESS).to_native()
+        func = functools.partial(self.cached_compile, code, env.coredata, extra_args=args, mode='preprocess')
+        if disable_cache:
+            func = functools.partial(self.compile, code, extra_args=args, mode='preprocess', temp_dir=env.scratch_dir)
+        with func() as p:
+            cached = p.cached
+            if p.returncode != 0:
+                raise mesonlib.EnvironmentException(f'Could not get define {dname!r}')
+        # Get the preprocessed value after the delimiter,
+        # minus the extra newline at the end and
+        # merge string literals.
+        return self._concatenate_string_literals(p.stdout.split(delim + '\n')[-1][:-1]), cached
+
+    def get_return_value(self, fname: str, rtype: str, prefix: str,
+                         env: 'Environment', extra_args: T.Optional[T.List[str]],
+                         dependencies: T.Optional[T.List['Dependency']]) -> T.Union[str, int]:
+        # TODO: rtype should be an enum.
+        # TODO: maybe we can use overload to tell mypy when this will return int vs str?
+        if rtype == 'string':
+            fmt = '%s'
+            cast = '(char*)'
+        elif rtype == 'int':
+            fmt = '%lli'
+            cast = '(long long int)'
+        else:
+            raise AssertionError(f'BUG: Unknown return type {rtype!r}')
+        code = f'''{prefix}
+        #include <stdio.h>
+        int main(void) {{
+            printf ("{fmt}", {cast} {fname}());
+            return 0;
+        }}'''
+        res = self.run(code, env, extra_args=extra_args, dependencies=dependencies)
+        if not res.compiled:
+            raise mesonlib.EnvironmentException(f'Could not get return value of {fname}()')
+        if rtype == 'string':
+            return res.stdout
+        elif rtype == 'int':
+            try:
+                return int(res.stdout.strip())
+            except ValueError:
+                raise mesonlib.EnvironmentException(f'Return value of {fname}() is not an int')
+        assert False, 'Unreachable'
+
+    @staticmethod
+    def _no_prototype_templ() -> T.Tuple[str, str]:
+        """
+        Try to find the function without a prototype from a header by defining
+        our own dummy prototype and trying to link with the C library (and
+        whatever else the compiler links in by default). This is very similar
+        to the check performed by Autoconf for AC_CHECK_FUNCS.
+        """
+        # Define the symbol to something else since it is defined by the
+        # includes or defines listed by the user or by the compiler. This may
+        # include, for instance _GNU_SOURCE which must be defined before
+        # limits.h, which includes features.h
+        # Then, undef the symbol to get rid of it completely.
+        head = '''
+        #define {func} meson_disable_define_of_{func}
+        {prefix}
+        #include <limits.h>
+        #undef {func}
+        '''
+        # Override any GCC internal prototype and declare our own definition for
+        # the symbol. Use char because that's unlikely to be an actual return
+        # value for a function which ensures that we override the definition.
+        head += '''
+        #ifdef __cplusplus
+        extern "C"
+        #endif
+        char {func} (void);
+        '''
+        # The actual function call
+        main = '''
+        int main(void) {{
+          return {func} ();
+        }}'''
+        return head, main
+
+    @staticmethod
+    def _have_prototype_templ() -> T.Tuple[str, str]:
+        """
+        Returns a head-er and main() call that uses the headers listed by the
+        user for the function prototype while checking if a function exists.
+        """
+        # Add the 'prefix', aka defines, includes, etc that the user provides
+        # This may include, for instance _GNU_SOURCE which must be defined
+        # before limits.h, which includes features.h
+        head = '{prefix}\n#include <limits.h>\n'
+        # We don't know what the function takes or returns, so return it as an int.
+        # Just taking the address or comparing it to void is not enough because
+        # compilers are smart enough to optimize it away. The resulting binary
+        # is not run so we don't care what the return value is.
+        main = '''\nint main(void) {{
+            void *a = (void*) &{func};
+            long long b = (long long) a;
+            return (int) b;
+        }}'''
+        return head, main
+
+    def has_function(self, funcname: str, prefix: str, env: 'Environment', *,
+                     extra_args: T.Optional[T.List[str]] = None,
+                     dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
+        """Determine if a function exists.
+
+        First, this function looks for the symbol in the default libraries
+        provided by the compiler (stdlib + a few others usually). If that
+        fails, it checks if any of the headers specified in the prefix provide
+        an implementation of the function, and if that fails, it checks if it's
+        implemented as a compiler-builtin.
+        """
+        if extra_args is None:
+            extra_args = []
+
+        # Short-circuit if the check is already provided by the cross-info file
+        varname = 'has function ' + funcname
+        varname = varname.replace(' ', '_')
+        if self.is_cross:
+            val = env.properties.host.get(varname, None)
+            if val is not None:
+                if isinstance(val, bool):
+                    return val, False
+                raise mesonlib.EnvironmentException(f'Cross variable {varname} is not a boolean.')
+
+        # TODO: we really need a protocol for this,
+        #
+        # class StrProto(typing.Protocol):
+        #    def __str__(self) -> str: ...
+        fargs = {'prefix': prefix, 'func': funcname}  # type: T.Dict[str, T.Union[str, bool, int]]
+
+        # glibc defines functions that are not available on Linux as stubs that
+        # fail with ENOSYS (such as e.g. lchmod). In this case we want to fail
+        # instead of detecting the stub as a valid symbol.
+        # We already included limits.h earlier to ensure that these are defined
+        # for stub functions.
+        stubs_fail = '''
+        #if defined __stub_{func} || defined __stub___{func}
+        fail fail fail this function is not going to work
+        #endif
+        '''
+
+        # If we have any includes in the prefix supplied by the user, assume
+        # that the user wants us to use the symbol prototype defined in those
+        # includes. If not, then try to do the Autoconf-style check with
+        # a dummy prototype definition of our own.
+        # This is needed when the linker determines symbol availability from an
+        # SDK based on the prototype in the header provided by the SDK.
+        # Ignoring this prototype would result in the symbol always being
+        # marked as available.
+        if '#include' in prefix:
+            head, main = self._have_prototype_templ()
+        else:
+            head, main = self._no_prototype_templ()
+        templ = head + stubs_fail + main
+
+        res, cached = self.links(templ.format(**fargs), env, extra_args=extra_args,
+                                 dependencies=dependencies)
+        if res:
+            return True, cached
+
+        # MSVC does not have compiler __builtin_-s.
+        if self.get_id() in {'msvc', 'intel-cl'}:
+            return False, False
+
+        # Detect function as a built-in
+        #
+        # Some functions like alloca() are defined as compiler built-ins which
+        # are inlined by the compiler and you can't take their address, so we
+        # need to look for them differently. On nice compilers like clang, we
+        # can just directly use the __has_builtin() macro.
+        fargs['no_includes'] = '#include' not in prefix
+        is_builtin = funcname.startswith('__builtin_')
+        fargs['is_builtin'] = is_builtin
+        fargs['__builtin_'] = '' if is_builtin else '__builtin_'
+        t = '''{prefix}
+        int main(void) {{
+
+        /* With some toolchains (MSYS2/mingw for example) the compiler
+         * provides various builtins which are not really implemented and
+         * fall back to the stdlib where they aren't provided and fail at
+         * build/link time. In case the user provides a header, including
+         * the header didn't lead to the function being defined, and the
+         * function we are checking isn't a builtin itself we assume the
+         * builtin is not functional and we just error out. */
+        #if !{no_includes:d} && !defined({func}) && !{is_builtin:d}
+            #error "No definition for {__builtin_}{func} found in the prefix"
+        #endif
+
+        #ifdef __has_builtin
+            #if !__has_builtin({__builtin_}{func})
+                #error "{__builtin_}{func} not found"
+            #endif
+        #elif ! defined({func})
+            {__builtin_}{func};
+        #endif
+        return 0;
+        }}'''
+        return self.links(t.format(**fargs), env, extra_args=extra_args,
+                          dependencies=dependencies)
+
+    def has_members(self, typename: str, membernames: T.List[str],
+                    prefix: str, env: 'Environment', *,
+                    extra_args: T.Optional[T.List[str]] = None,
+                    dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
+        if extra_args is None:
+            extra_args = []
+        # Create code that accesses all members
+        members = ''
+        for member in membernames:
+            members += f'foo.{member};\n'
+        t = f'''{prefix}
+        void bar(void) {{
+            {typename} foo;
+            {members}
+        }};'''
+        return self.compiles(t, env, extra_args=extra_args,
+                             dependencies=dependencies)
+
+    def has_type(self, typename: str, prefix: str, env: 'Environment', extra_args: T.List[str],
+                 dependencies: T.Optional[T.List['Dependency']] = None) -> T.Tuple[bool, bool]:
+        t = f'''{prefix}
+        void bar(void) {{
+            sizeof({typename});
+        }};'''
+        return self.compiles(t, env, extra_args=extra_args,
+                             dependencies=dependencies)
+
+    def symbols_have_underscore_prefix(self, env: 'Environment') -> bool:
+        '''
+        Check if the compiler prefixes an underscore to global C symbols
+        '''
+        symbol_name = b'meson_uscore_prefix'
+        code = '''#ifdef __cplusplus
+        extern "C" {
+        #endif
+        void ''' + symbol_name.decode() + ''' (void) {}
+        #ifdef __cplusplus
+        }
+        #endif
+        '''
+        args = self.get_compiler_check_args(CompileCheckMode.COMPILE)
+        n = 'symbols_have_underscore_prefix'
+        with self._build_wrapper(code, env, extra_args=args, mode='compile', want_output=True, temp_dir=env.scratch_dir) as p:
+            if p.returncode != 0:
+                raise RuntimeError(f'BUG: Unable to compile {n!r} check: {p.stdout}')
+            if not os.path.isfile(p.output_name):
+                raise RuntimeError(f'BUG: Can\'t find compiled test code for {n!r} check')
+            with open(p.output_name, 'rb') as o:
+                for line in o:
+                    # Check if the underscore form of the symbol is somewhere
+                    # in the output file.
+                    if b'_' + symbol_name in line:
+                        mlog.debug("Symbols have underscore prefix: YES")
+                        return True
+                    # Else, check if the non-underscored form is present
+                    elif symbol_name in line:
+                        mlog.debug("Symbols have underscore prefix: NO")
+                        return False
+        raise RuntimeError(f'BUG: {n!r} check failed unexpectedly')
+
+    def _get_patterns(self, env: 'Environment', prefixes: T.List[str], suffixes: T.List[str], shared: bool = False) -> T.List[str]:
+        patterns = []  # type: T.List[str]
+        for p in prefixes:
+            for s in suffixes:
+                patterns.append(p + '{}.' + s)
+        if shared and env.machines[self.for_machine].is_openbsd():
+            # Shared libraries on OpenBSD can be named libfoo.so.X.Y:
+            # https://www.openbsd.org/faq/ports/specialtopics.html#SharedLibs
+            #
+            # This globbing is probably the best matching we can do since regex
+            # is expensive. It's wrong in many edge cases, but it will match
+            # correctly-named libraries and hopefully no one on OpenBSD names
+            # their files libfoo.so.9a.7b.1.0
+            for p in prefixes:
+                patterns.append(p + '{}.so.[0-9]*.[0-9]*')
+        return patterns
+
+    def get_library_naming(self, env: 'Environment', libtype: LibType, strict: bool = False) -> T.Tuple[str, ...]:
+        '''
+        Get library prefixes and suffixes for the target platform ordered by
+        priority
+        '''
+        stlibext = ['a']
+        # We've always allowed libname to be both `foo` and `libfoo`, and now
+        # people depend on it. Also, some people use prebuilt `foo.so` instead
+        # of `libfoo.so` for unknown reasons, and may also want to create
+        # `foo.so` by setting name_prefix to ''
+        if strict and not isinstance(self, VisualStudioLikeCompiler): # lib prefix is not usually used with msvc
+            prefixes = ['lib']
+        else:
+            prefixes = ['lib', '']
+        # Library suffixes and prefixes
+        if env.machines[self.for_machine].is_darwin():
+            shlibext = ['dylib', 'so']
+        elif env.machines[self.for_machine].is_windows():
+            # FIXME: .lib files can be import or static so we should read the
+            # file, figure out which one it is, and reject the wrong kind.
+            if isinstance(self, VisualStudioLikeCompiler):
+                shlibext = ['lib']
+            else:
+                shlibext = ['dll.a', 'lib', 'dll']
+            # Yep, static libraries can also be foo.lib
+            stlibext += ['lib']
+        elif env.machines[self.for_machine].is_cygwin():
+            shlibext = ['dll', 'dll.a']
+            prefixes = ['cyg'] + prefixes
+        else:
+            # Linux/BSDs
+            shlibext = ['so']
+        # Search priority
+        if libtype is LibType.PREFER_SHARED:
+            patterns = self._get_patterns(env, prefixes, shlibext, True)
+            patterns.extend([x for x in self._get_patterns(env, prefixes, stlibext, False) if x not in patterns])
+        elif libtype is LibType.PREFER_STATIC:
+            patterns = self._get_patterns(env, prefixes, stlibext, False)
+            patterns.extend([x for x in self._get_patterns(env, prefixes, shlibext, True) if x not in patterns])
+        elif libtype is LibType.SHARED:
+            patterns = self._get_patterns(env, prefixes, shlibext, True)
+        else:
+            assert libtype is LibType.STATIC
+            patterns = self._get_patterns(env, prefixes, stlibext, False)
+        return tuple(patterns)
+
+    @staticmethod
+    def _sort_shlibs_openbsd(libs: T.List[str]) -> T.List[str]:
+        filtered = []  # type: T.List[str]
+        for lib in libs:
+            # Validate file as a shared library of type libfoo.so.X.Y
+            ret = lib.rsplit('.so.', maxsplit=1)
+            if len(ret) != 2:
+                continue
+            try:
+                float(ret[1])
+            except ValueError:
+                continue
+            filtered.append(lib)
+        float_cmp = lambda x: float(x.rsplit('.so.', maxsplit=1)[1])
+        return sorted(filtered, key=float_cmp, reverse=True)
+
+    @classmethod
+    def _get_trials_from_pattern(cls, pattern: str, directory: str, libname: str) -> T.List[Path]:
+        f = Path(directory) / pattern.format(libname)
+        # Globbing for OpenBSD
+        if '*' in pattern:
+            # NOTE: globbing matches directories and broken symlinks
+            # so we have to do an isfile test on it later
+            return [Path(x) for x in cls._sort_shlibs_openbsd(glob.glob(str(f)))]
+        return [f]
+
+    @staticmethod
+    def _get_file_from_list(env: 'Environment', paths: T.List[Path]) -> Path:
+        '''
+        We just check whether the library exists. We can't do a link check
+        because the library might have unresolved symbols that require other
+        libraries. On macOS we check if the library matches our target
+        architecture.
+        '''
+        # If not building on macOS for Darwin, do a simple file check
+        if not env.machines.host.is_darwin() or not env.machines.build.is_darwin():
+            for p in paths:
+                if p.is_file():
+                    return p
+        # Run `lipo` and check if the library supports the arch we want
+        for p in paths:
+            if not p.is_file():
+                continue
+            archs = mesonlib.darwin_get_object_archs(str(p))
+            if archs and env.machines.host.cpu_family in archs:
+                return p
+            else:
+                mlog.debug(f'Rejected {p}, supports {archs} but need {env.machines.host.cpu_family}')
+        return None
+
+    @functools.lru_cache()
+    def output_is_64bit(self, env: 'Environment') -> bool:
+        '''
+        returns true if the output produced is 64-bit, false if 32-bit
+        '''
+        return self.sizeof('void *', '', env) == 8
+
+    def _find_library_real(self, libname: str, env: 'Environment', extra_dirs: T.List[str], code: str, libtype: LibType) -> T.Optional[T.List[str]]:
+        # First try if we can just add the library as -l.
+        # Gcc + co seem to prefer builtin lib dirs to -L dirs.
+        # Only try to find std libs if no extra dirs specified.
+        # The built-in search procedure will always favour .so and then always
+        # search for .a. This is only allowed if libtype is LibType.PREFER_SHARED
+        if ((not extra_dirs and libtype is LibType.PREFER_SHARED) or
+                libname in self.internal_libs):
+            cargs = ['-l' + libname]
+            largs = self.get_linker_always_args() + self.get_allow_undefined_link_args()
+            extra_args = cargs + self.linker_to_compiler_args(largs)
+
+            if self.links(code, env, extra_args=extra_args, disable_cache=True)[0]:
+                return cargs
+            # Don't do a manual search for internal libs
+            if libname in self.internal_libs:
+                return None
+        # Not found or we want to use a specific libtype? Try to find the
+        # library file itself.
+        patterns = self.get_library_naming(env, libtype)
+        # try to detect if we are 64-bit or 32-bit. If we can't
+        # detect, we will just skip path validity checks done in
+        # get_library_dirs() call
+        try:
+            if self.output_is_64bit(env):
+                elf_class = 2
+            else:
+                elf_class = 1
+        except (mesonlib.MesonException, KeyError): # TODO evaluate if catching KeyError is wanted here
+            elf_class = 0
+        # Search in the specified dirs, and then in the system libraries
+        for d in itertools.chain(extra_dirs, self.get_library_dirs(env, elf_class)):
+            for p in patterns:
+                trials = self._get_trials_from_pattern(p, d, libname)
+                if not trials:
+                    continue
+                trial = self._get_file_from_list(env, trials)
+                if not trial:
+                    continue
+                return [trial.as_posix()]
+        return None
+
+    def _find_library_impl(self, libname: str, env: 'Environment', extra_dirs: T.List[str],
+                         code: str, libtype: LibType) -> T.Optional[T.List[str]]:
+        # These libraries are either built-in or invalid
+        if libname in self.ignore_libs:
+            return []
+        if isinstance(extra_dirs, str):
+            extra_dirs = [extra_dirs]
+        key = (tuple(self.exelist), libname, tuple(extra_dirs), code, libtype)
+        if key not in self.find_library_cache:
+            value = self._find_library_real(libname, env, extra_dirs, code, libtype)
+            self.find_library_cache[key] = value
+        else:
+            value = self.find_library_cache[key]
+        if value is None:
+            return None
+        return value.copy()
+
+    def find_library(self, libname: str, env: 'Environment', extra_dirs: T.List[str],
+                     libtype: LibType = LibType.PREFER_SHARED) -> T.Optional[T.List[str]]:
+        code = 'int main(void) { return 0; }\n'
+        return self._find_library_impl(libname, env, extra_dirs, code, libtype)
+
+    def find_framework_paths(self, env: 'Environment') -> T.List[str]:
+        '''
+        These are usually /Library/Frameworks and /System/Library/Frameworks,
+        unless you select a particular macOS SDK with the -isysroot flag.
+        You can also add to this by setting -F in CFLAGS.
+        '''
+        # TODO: this really needs to be *AppleClang*, not just any clang.
+        if self.id != 'clang':
+            raise mesonlib.MesonException('Cannot find framework path with non-clang compiler')
+        # Construct the compiler command-line
+        commands = self.get_exelist() + ['-v', '-E', '-']
+        commands += self.get_always_args()
+        # Add CFLAGS/CXXFLAGS/OBJCFLAGS/OBJCXXFLAGS from the env
+        commands += env.coredata.get_external_args(self.for_machine, self.language)
+        mlog.debug('Finding framework path by running: ', ' '.join(commands), '\n')
+        os_env = os.environ.copy()
+        os_env['LC_ALL'] = 'C'
+        _, _, stde = mesonlib.Popen_safe(commands, env=os_env, stdin=subprocess.PIPE)
+        paths = []  # T.List[str]
+        for line in stde.split('\n'):
+            if '(framework directory)' not in line:
+                continue
+            # line is of the form:
+            # ` /path/to/framework (framework directory)`
+            paths.append(line[:-21].strip())
+        return paths
+
+    def _find_framework_real(self, name: str, env: 'Environment', extra_dirs: T.List[str], allow_system: bool) -> T.Optional[T.List[str]]:
+        code = 'int main(void) { return 0; }'
+        link_args = []
+        for d in extra_dirs:
+            link_args += ['-F' + d]
+        # We can pass -Z to disable searching in the system frameworks, but
+        # then we must also pass -L/usr/lib to pick up libSystem.dylib
+        extra_args = [] if allow_system else ['-Z', '-L/usr/lib']
+        link_args += ['-framework', name]
+        if self.links(code, env, extra_args=(extra_args + link_args), disable_cache=True)[0]:
+            return link_args
+        return None
+
+    def _find_framework_impl(self, name: str, env: 'Environment', extra_dirs: T.List[str],
+                            allow_system: bool) -> T.Optional[T.List[str]]:
+        if isinstance(extra_dirs, str):
+            extra_dirs = [extra_dirs]
+        key = (tuple(self.exelist), name, tuple(extra_dirs), allow_system)
+        if key in self.find_framework_cache:
+            value = self.find_framework_cache[key]
+        else:
+            value = self._find_framework_real(name, env, extra_dirs, allow_system)
+            self.find_framework_cache[key] = value
+        if value is None:
+            return None
+        return value.copy()
+
+    def find_framework(self, name: str, env: 'Environment', extra_dirs: T.List[str],
+                       allow_system: bool = True) -> T.Optional[T.List[str]]:
+        '''
+        Finds the framework with the specified name, and returns link args for
+        the same or returns None when the framework is not found.
+        '''
+        # TODO: maybe this belongs in clang? also, should probably check for macOS?
+        if self.id != 'clang':
+            raise mesonlib.MesonException('Cannot find frameworks with non-clang compiler')
+        return self._find_framework_impl(name, env, extra_dirs, allow_system)
+
+    def get_crt_compile_args(self, crt_val: str, buildtype: str) -> T.List[str]:
+        # TODO: does this belong here or in GnuLike or maybe PosixLike?
+        return []
+
+    def get_crt_link_args(self, crt_val: str, buildtype: str) -> T.List[str]:
+        # TODO: does this belong here or in GnuLike or maybe PosixLike?
+        return []
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        # TODO: does this belong here or in GnuLike or maybe PosixLike?
+        host_m = env.machines[self.for_machine]
+        if host_m.is_haiku() or host_m.is_darwin():
+            return []
+        return ['-pthread']
+
+    def linker_to_compiler_args(self, args: T.List[str]) -> T.List[str]:
+        return args.copy()
+
+    def has_arguments(self, args: T.List[str], env: 'Environment', code: str,
+                      mode: str) -> T.Tuple[bool, bool]:
+        return self.compiles(code, env, extra_args=args, mode=mode)
+
+    def _has_multi_arguments(self, args: T.List[str], env: 'Environment', code: str) -> T.Tuple[bool, bool]:
+        new_args = []  # type: T.List[str]
+        for arg in args:
+            # some compilers, e.g. GCC, don't warn for unsupported warning-disable
+            # flags, so when we are testing a flag like "-Wno-forgotten-towel", also
+            # check the equivalent enable flag too "-Wforgotten-towel"
+            if arg.startswith('-Wno-'):
+                new_args.append('-W' + arg[5:])
+            if arg.startswith('-Wl,'):
+                mlog.warning(f'{arg} looks like a linker argument, '
+                             'but has_argument and other similar methods only '
+                             'support checking compiler arguments. Using them '
+                             'to check linker arguments are never supported, '
+                             'and results are likely to be wrong regardless of '
+                             'the compiler you are using. has_link_argument or '
+                             'other similar method can be used instead.')
+            new_args.append(arg)
+        return self.has_arguments(new_args, env, code, mode='compile')
+
+    def has_multi_arguments(self, args: T.List[str], env: 'Environment') -> T.Tuple[bool, bool]:
+        return self._has_multi_arguments(args, env, 'extern int i;\nint i;\n')
+
+    def _has_multi_link_arguments(self, args: T.List[str], env: 'Environment', code: str) -> T.Tuple[bool, bool]:
+        # First time we check for link flags we need to first check if we have
+        # --fatal-warnings, otherwise some linker checks could give some
+        # false positive.
+        args = self.linker.fatal_warnings() + args
+        args = self.linker_to_compiler_args(args)
+        return self.has_arguments(args, env, code, mode='link')
+
+    def has_multi_link_arguments(self, args: T.List[str], env: 'Environment') -> T.Tuple[bool, bool]:
+        return self._has_multi_link_arguments(args, env, 'int main(void) { return 0; }\n')
+
+    @staticmethod
+    def _concatenate_string_literals(s: str) -> str:
+        pattern = re.compile(r'(?P<pre>.*([^\\]")|^")(?P<str1>([^\\"]|\\.)*)"\s+"(?P<str2>([^\\"]|\\.)*)(?P<post>".*)')
+        ret = s
+        m = pattern.match(ret)
+        while m:
+            ret = ''.join(m.group('pre', 'str1', 'str2', 'post'))
+            m = pattern.match(ret)
+        return ret
+
+    def get_has_func_attribute_extra_args(self, name: str) -> T.List[str]:
+        # Most compilers (such as GCC and Clang) only warn about unknown or
+        # ignored attributes, so force an error. Overridden in GCC and Clang
+        # mixins.
+        return ['-Werror']
+
+    def has_func_attribute(self, name: str, env: 'Environment') -> T.Tuple[bool, bool]:
+        # Just assume that if we're not on windows that dllimport and dllexport
+        # don't work
+        m = env.machines[self.for_machine]
+        if not (m.is_windows() or m.is_cygwin()):
+            if name in ['dllimport', 'dllexport']:
+                return False, False
+
+        return self.compiles(self.attribute_check_func(name), env,
+                             extra_args=self.get_has_func_attribute_extra_args(name))
+
+    def get_disable_assert_args(self) -> T.List[str]:
+        return ['-DNDEBUG']
diff --git a/meson/mesonbuild/compilers/mixins/compcert.py b/meson/mesonbuild/compilers/mixins/compcert.py
new file mode 100644
index 000000000..3211f6af2
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/compcert.py
@@ -0,0 +1,131 @@
+# Copyright 2012-2019 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.
+
+"""Representations specific to the CompCert C compiler family."""
+
+import os
+import re
+import typing as T
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+ccomp_buildtype_args = {
+    'plain': [''],
+    'debug': ['-O0', '-g'],
+    'debugoptimized': ['-O0', '-g'],
+    'release': ['-03'],
+    'minsize': ['-Os'],
+    'custom': ['-Obranchless'],
+}  # type: T.Dict[str, T.List[str]]
+
+ccomp_optimization_args = {
+    '0': ['-O0'],
+    'g': ['-O0'],
+    '1': ['-O1'],
+    '2': ['-O2'],
+    '3': ['-O3'],
+    's': ['-Os']
+}  # type: T.Dict[str, T.List[str]]
+
+ccomp_debug_args = {
+    False: [],
+    True: ['-g']
+}  # type: T.Dict[bool, T.List[str]]
+
+# As of CompCert 20.04, these arguments should be passed to the underlying gcc linker (via -WUl,<arg>)
+# There are probably (many) more, but these are those used by picolibc
+ccomp_args_to_wul = [
+        r"^-ffreestanding$",
+        r"^-r$"
+] # type: T.List[str]
+
+class CompCertCompiler(Compiler):
+
+    def __init__(self) -> None:
+        self.id = 'ccomp'
+        # Assembly
+        self.can_compile_suffixes.add('s')
+        default_warn_args = []  # type: T.List[str]
+        self.warn_args = {'0': [],
+                          '1': default_warn_args,
+                          '2': default_warn_args + [],
+                          '3': default_warn_args + []}  # type: T.Dict[str, T.List[str]]
+
+    def get_always_args(self) -> T.List[str]:
+        return []
+
+    def get_pic_args(self) -> T.List[str]:
+        # As of now, CompCert does not support PIC
+        return []
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return ccomp_buildtype_args[buildtype]
+
+    def get_pch_suffix(self) -> str:
+        return 'pch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        return []
+
+    def unix_args_to_native(self, args: T.List[str]) -> T.List[str]:
+        "Always returns a copy that can be independently mutated"
+        patched_args = []  # type: T.List[str]
+        for arg in args:
+            added = 0
+            for ptrn in ccomp_args_to_wul:
+                if re.match(ptrn, arg):
+                    patched_args.append('-WUl,' + arg)
+                    added = 1
+            if not added:
+                patched_args.append(arg)
+        return patched_args
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    def get_preprocess_only_args(self) -> T.List[str]:
+        return ['-E']
+
+    def get_compile_only_args(self) -> T.List[str]:
+        return ['-c']
+
+    def get_coverage_args(self) -> T.List[str]:
+        return []
+
+    def get_no_stdinc_args(self) -> T.List[str]:
+        return ['-nostdinc']
+
+    def get_no_stdlib_link_args(self) -> T.List[str]:
+        return ['-nostdlib']
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return ccomp_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return ccomp_debug_args[is_debug]
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:9] == '-I':
+                parameter_list[idx] = i[:9] + os.path.normpath(os.path.join(build_dir, i[9:]))
+
+        return parameter_list
diff --git a/meson/mesonbuild/compilers/mixins/elbrus.py b/meson/mesonbuild/compilers/mixins/elbrus.py
new file mode 100644
index 000000000..16f621005
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/elbrus.py
@@ -0,0 +1,82 @@
+# Copyright 2019 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.
+
+"""Abstractions for the Elbrus family of compilers."""
+
+import os
+import typing as T
+import subprocess
+import re
+
+from .gnu import GnuLikeCompiler
+from .gnu import gnu_optimization_args
+from ...mesonlib import Popen_safe, OptionKey
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+
+
+class ElbrusCompiler(GnuLikeCompiler):
+    # Elbrus compiler is nearly like GCC, but does not support
+    # PCH, LTO, sanitizers and color output as of version 1.21.x.
+
+    def __init__(self) -> None:
+        super().__init__()
+        self.id = 'lcc'
+        self.base_options = {OptionKey(o) for o in ['b_pgo', 'b_coverage', 'b_ndebug', 'b_staticpic', 'b_lundef', 'b_asneeded']}
+
+    # FIXME: use _build_wrapper to call this so that linker flags from the env
+    # get applied
+    def get_library_dirs(self, env: 'Environment', elf_class: T.Optional[int] = None) -> T.List[str]:
+        os_env = os.environ.copy()
+        os_env['LC_ALL'] = 'C'
+        stdo = Popen_safe(self.exelist + ['--print-search-dirs'], env=os_env)[1]
+        for line in stdo.split('\n'):
+            if line.startswith('libraries:'):
+                # lcc does not include '=' in --print-search-dirs output. Also it could show nonexistent dirs.
+                libstr = line.split(' ', 1)[1]
+                return [os.path.realpath(p) for p in libstr.split(':') if os.path.exists(p)]
+        return []
+
+    def get_program_dirs(self, env: 'Environment') -> T.List[str]:
+        os_env = os.environ.copy()
+        os_env['LC_ALL'] = 'C'
+        stdo = Popen_safe(self.exelist + ['--print-search-dirs'], env=os_env)[1]
+        for line in stdo.split('\n'):
+            if line.startswith('programs:'):
+                # lcc does not include '=' in --print-search-dirs output.
+                libstr = line.split(' ', 1)[1]
+                return [os.path.realpath(p) for p in libstr.split(':')]
+        return []
+
+    def get_default_include_dirs(self) -> T.List[str]:
+        os_env = os.environ.copy()
+        os_env['LC_ALL'] = 'C'
+        p = subprocess.Popen(self.exelist + ['-xc', '-E', '-v', '-'], env=os_env, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        stderr = p.stderr.read().decode('utf-8', errors='replace')
+        includes = []
+        for line in stderr.split('\n'):
+            if line.lstrip().startswith('--sys_include'):
+                includes.append(re.sub(r'\s*\\$', '', re.sub(r'^\s*--sys_include\s*', '', line)))
+        return includes
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return gnu_optimization_args[optimization_level]
+
+    def get_pch_suffix(self) -> str:
+        # Actually it's not supported for now, but probably will be supported in future
+        return 'pch'
+
+    def openmp_flags(self) -> T.List[str]:
+        return ['-fopenmp']
diff --git a/meson/mesonbuild/compilers/mixins/emscripten.py b/meson/mesonbuild/compilers/mixins/emscripten.py
new file mode 100644
index 000000000..226cc1531
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/emscripten.py
@@ -0,0 +1,69 @@
+# Copyright 2019 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.
+
+"""Provides a mixin for shared code between C and C++ Emscripten compilers."""
+
+import os.path
+import typing as T
+
+from ... import coredata
+from ...mesonlib import OptionKey
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+
+class EmscriptenMixin(Compiler):
+
+    def _get_compile_output(self, dirname: str, mode: str) -> str:
+        # In pre-processor mode, the output is sent to stdout and discarded
+        if mode == 'preprocess':
+            return None
+        # Unlike sane toolchains, emcc infers the kind of output from its name.
+        # This is the only reason why this method is overridden; compiler tests
+        # do not work well with the default exe/obj suffices.
+        if mode == 'link':
+            suffix = 'js'
+        else:
+            suffix = 'o'
+        return os.path.join(dirname, 'output.' + suffix)
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return ['-s', 'USE_PTHREADS=1']
+
+    def thread_link_flags(self, env: 'Environment') -> T.List[str]:
+        args = ['-s', 'USE_PTHREADS=1']
+        count: int = env.coredata.options[OptionKey('thread_count', lang=self.language, machine=self.for_machine)].value
+        if count:
+            args.extend(['-s', f'PTHREAD_POOL_SIZE={count}'])
+        return args
+
+    def get_options(self) -> 'coredata.KeyedOptionDictType':
+        opts = super().get_options()
+        key = OptionKey('thread_count', machine=self.for_machine, lang=self.language)
+        opts.update({
+            key: coredata.UserIntegerOption(
+                'Number of threads to use in web assembly, set to 0 to disable',
+                (0, None, 4),  # Default was picked at random
+            ),
+        })
+
+        return opts
diff --git a/meson/mesonbuild/compilers/mixins/gnu.py b/meson/mesonbuild/compilers/mixins/gnu.py
new file mode 100644
index 000000000..bc40af494
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/gnu.py
@@ -0,0 +1,398 @@
+# Copyright 2019 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.
+
+"""Provides mixins for GNU compilers and GNU-like compilers."""
+
+import abc
+import functools
+import os
+import multiprocessing
+import pathlib
+import re
+import subprocess
+import typing as T
+
+from ... import mesonlib
+from ... import mlog
+from ...mesonlib import OptionKey
+
+if T.TYPE_CHECKING:
+    from ..._typing import ImmutableListProtocol
+    from ...environment import Environment
+    from ..compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+# XXX: prevent circular references.
+# FIXME: this really is a posix interface not a c-like interface
+clike_debug_args = {
+    False: [],
+    True: ['-g'],
+}  # type: T.Dict[bool, T.List[str]]
+
+gnulike_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+gnu_optimization_args = {
+    '0': [],
+    'g': ['-Og'],
+    '1': ['-O1'],
+    '2': ['-O2'],
+    '3': ['-O3'],
+    's': ['-Os'],
+}  # type: T.Dict[str, T.List[str]]
+
+gnulike_instruction_set_args = {
+    'mmx': ['-mmmx'],
+    'sse': ['-msse'],
+    'sse2': ['-msse2'],
+    'sse3': ['-msse3'],
+    'ssse3': ['-mssse3'],
+    'sse41': ['-msse4.1'],
+    'sse42': ['-msse4.2'],
+    'avx': ['-mavx'],
+    'avx2': ['-mavx2'],
+    'neon': ['-mfpu=neon'],
+}  # type: T.Dict[str, T.List[str]]
+
+gnu_symbol_visibility_args = {
+    '': [],
+    'default': ['-fvisibility=default'],
+    'internal': ['-fvisibility=internal'],
+    'hidden': ['-fvisibility=hidden'],
+    'protected': ['-fvisibility=protected'],
+    'inlineshidden': ['-fvisibility=hidden', '-fvisibility-inlines-hidden'],
+}  # type: T.Dict[str, T.List[str]]
+
+gnu_color_args = {
+    'auto': ['-fdiagnostics-color=auto'],
+    'always': ['-fdiagnostics-color=always'],
+    'never': ['-fdiagnostics-color=never'],
+}  # type: T.Dict[str, T.List[str]]
+
+
+@functools.lru_cache(maxsize=None)
+def gnulike_default_include_dirs(compiler: T.Tuple[str, ...], lang: str) -> 'ImmutableListProtocol[str]':
+    lang_map = {
+        'c': 'c',
+        'cpp': 'c++',
+        'objc': 'objective-c',
+        'objcpp': 'objective-c++'
+    }
+    if lang not in lang_map:
+        return []
+    lang = lang_map[lang]
+    env = os.environ.copy()
+    env["LC_ALL"] = 'C'
+    cmd = list(compiler) + [f'-x{lang}', '-E', '-v', '-']
+    p = subprocess.Popen(
+        cmd,
+        stdin=subprocess.DEVNULL,
+        stderr=subprocess.STDOUT,
+        stdout=subprocess.PIPE,
+        env=env
+    )
+    stdout = p.stdout.read().decode('utf-8', errors='replace')
+    parse_state = 0
+    paths = []  # type: T.List[str]
+    for line in stdout.split('\n'):
+        line = line.strip(' \n\r\t')
+        if parse_state == 0:
+            if line == '#include "..." search starts here:':
+                parse_state = 1
+        elif parse_state == 1:
+            if line == '#include <...> search starts here:':
+                parse_state = 2
+            else:
+                paths.append(line)
+        elif parse_state == 2:
+            if line == 'End of search list.':
+                break
+            else:
+                paths.append(line)
+    if not paths:
+        mlog.warning('No include directory found parsing "{cmd}" output'.format(cmd=" ".join(cmd)))
+    # Append a normalized copy of paths to make path lookup easier
+    paths += [os.path.normpath(x) for x in paths]
+    return paths
+
+
+class GnuLikeCompiler(Compiler, metaclass=abc.ABCMeta):
+    """
+    GnuLikeCompiler is a common interface to all compilers implementing
+    the GNU-style commandline interface. This includes GCC, Clang
+    and ICC. Certain functionality between them is different and requires
+    that the actual concrete subclass define their own implementation.
+    """
+
+    LINKER_PREFIX = '-Wl,'
+
+    def __init__(self) -> None:
+        self.base_options = {
+            OptionKey(o) for o in ['b_pch', 'b_lto', 'b_pgo', 'b_coverage',
+                                   'b_ndebug', 'b_staticpic', 'b_pie']}
+        if not (self.info.is_windows() or self.info.is_cygwin() or self.info.is_openbsd()):
+            self.base_options.add(OptionKey('b_lundef'))
+        if not self.info.is_windows() or self.info.is_cygwin():
+            self.base_options.add(OptionKey('b_asneeded'))
+        if not self.info.is_hurd():
+            self.base_options.add(OptionKey('b_sanitize'))
+        # All GCC-like backends can do assembly
+        self.can_compile_suffixes.add('s')
+
+    def get_pic_args(self) -> T.List[str]:
+        if self.info.is_windows() or self.info.is_cygwin() or self.info.is_darwin():
+            return [] # On Window and OS X, pic is always on.
+        return ['-fPIC']
+
+    def get_pie_args(self) -> T.List[str]:
+        return ['-fPIE']
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return gnulike_buildtype_args[buildtype]
+
+    @abc.abstractmethod
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        pass
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return clike_debug_args[is_debug]
+
+    @abc.abstractmethod
+    def get_pch_suffix(self) -> str:
+        pass
+
+    def split_shlib_to_parts(self, fname: str) -> T.Tuple[str, str]:
+        return os.path.dirname(fname), fname
+
+    def get_instruction_set_args(self, instruction_set: str) -> T.Optional[T.List[str]]:
+        return gnulike_instruction_set_args.get(instruction_set, None)
+
+    def get_default_include_dirs(self) -> T.List[str]:
+        return gnulike_default_include_dirs(tuple(self.exelist), self.language).copy()
+
+    @abc.abstractmethod
+    def openmp_flags(self) -> T.List[str]:
+        pass
+
+    def gnu_symbol_visibility_args(self, vistype: str) -> T.List[str]:
+        return gnu_symbol_visibility_args[vistype]
+
+    def gen_vs_module_defs_args(self, defsfile: str) -> T.List[str]:
+        if not isinstance(defsfile, str):
+            raise RuntimeError('Module definitions file should be str')
+        # On Windows targets, .def files may be specified on the linker command
+        # line like an object file.
+        if self.info.is_windows() or self.info.is_cygwin():
+            return [defsfile]
+        # For other targets, discard the .def file.
+        return []
+
+    def get_argument_syntax(self) -> str:
+        return 'gcc'
+
+    def get_profile_generate_args(self) -> T.List[str]:
+        return ['-fprofile-generate']
+
+    def get_profile_use_args(self) -> T.List[str]:
+        return ['-fprofile-use', '-fprofile-correction']
+
+    def get_gui_app_args(self, value: bool) -> T.List[str]:
+        return ['-mwindows' if value else '-mconsole']
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:2] == '-I' or i[:2] == '-L':
+                parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))
+
+        return parameter_list
+
+    @functools.lru_cache()
+    def _get_search_dirs(self, env: 'Environment') -> str:
+        extra_args = ['--print-search-dirs']
+        with self._build_wrapper('', env, extra_args=extra_args,
+                                 dependencies=None, mode='compile',
+                                 want_output=True) as p:
+            return p.stdout
+
+    def _split_fetch_real_dirs(self, pathstr: str) -> T.List[str]:
+        # We need to use the path separator used by the compiler for printing
+        # lists of paths ("gcc --print-search-dirs"). By default
+        # we assume it uses the platform native separator.
+        pathsep = os.pathsep
+
+        # clang uses ':' instead of ';' on Windows https://reviews.llvm.org/D61121
+        # so we need to repair things like 'C:\foo:C:\bar'
+        if pathsep == ';':
+            pathstr = re.sub(r':([^/\\])', r';\1', pathstr)
+
+        # pathlib treats empty paths as '.', so filter those out
+        paths = [p for p in pathstr.split(pathsep) if p]
+
+        result = []
+        for p in paths:
+            # GCC returns paths like this:
+            # /usr/lib/gcc/x86_64-linux-gnu/8/../../../../x86_64-linux-gnu/lib
+            # It would make sense to normalize them to get rid of the .. parts
+            # Sadly when you are on a merged /usr fs it also kills these:
+            # /lib/x86_64-linux-gnu
+            # since /lib is a symlink to /usr/lib. This would mean
+            # paths under /lib would be considered not a "system path",
+            # which is wrong and breaks things. Store everything, just to be sure.
+            pobj = pathlib.Path(p)
+            unresolved = pobj.as_posix()
+            if pobj.exists():
+                if unresolved not in result:
+                    result.append(unresolved)
+                try:
+                    resolved = pathlib.Path(p).resolve().as_posix()
+                    if resolved not in result:
+                        result.append(resolved)
+                except FileNotFoundError:
+                    pass
+        return result
+
+    def get_compiler_dirs(self, env: 'Environment', name: str) -> T.List[str]:
+        '''
+        Get dirs from the compiler, either `libraries:` or `programs:`
+        '''
+        stdo = self._get_search_dirs(env)
+        for line in stdo.split('\n'):
+            if line.startswith(name + ':'):
+                return self._split_fetch_real_dirs(line.split('=', 1)[1])
+        return []
+
+    def get_lto_compile_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
+        # This provides a base for many compilers, GCC and Clang override this
+        # for their specific arguments
+        return ['-flto']
+
+    def sanitizer_compile_args(self, value: str) -> T.List[str]:
+        if value == 'none':
+            return []
+        args = ['-fsanitize=' + value]
+        if 'address' in value:  # for -fsanitize=address,undefined
+            args.append('-fno-omit-frame-pointer')
+        return args
+
+    def get_output_args(self, target: str) -> T.List[str]:
+        return ['-o', target]
+
+    def get_dependency_gen_args(self, outtarget: str, outfile: str) -> T.List[str]:
+        return ['-MD', '-MQ', outtarget, '-MF', outfile]
+
+    def get_compile_only_args(self) -> T.List[str]:
+        return ['-c']
+
+    def get_include_args(self, path: str, is_system: bool) -> T.List[str]:
+        if not path:
+            path = '.'
+        if is_system:
+            return ['-isystem' + path]
+        return ['-I' + path]
+
+    @classmethod
+    def use_linker_args(cls, linker: str) -> T.List[str]:
+        if linker not in {'gold', 'bfd', 'lld'}:
+            raise mesonlib.MesonException(
+                f'Unsupported linker, only bfd, gold, and lld are supported, not {linker}.')
+        return [f'-fuse-ld={linker}']
+
+    def get_coverage_args(self) -> T.List[str]:
+        return ['--coverage']
+
+
+class GnuCompiler(GnuLikeCompiler):
+    """
+    GnuCompiler represents an actual GCC in its many incarnations.
+    Compilers imitating GCC (Clang/Intel) should use the GnuLikeCompiler ABC.
+    """
+
+    def __init__(self, defines: T.Optional[T.Dict[str, str]]):
+        super().__init__()
+        self.id = 'gcc'
+        self.defines = defines or {}
+        self.base_options.update({OptionKey('b_colorout'), OptionKey('b_lto_threads')})
+
+    def get_colorout_args(self, colortype: str) -> T.List[str]:
+        if mesonlib.version_compare(self.version, '>=4.9.0'):
+            return gnu_color_args[colortype][:]
+        return []
+
+    def get_warn_args(self, level: str) -> T.List[str]:
+        # Mypy doesn't understand cooperative inheritance
+        args = super().get_warn_args(level)
+        if mesonlib.version_compare(self.version, '<4.8.0') and '-Wpedantic' in args:
+            # -Wpedantic was added in 4.8.0
+            # https://gcc.gnu.org/gcc-4.8/changes.html
+            args[args.index('-Wpedantic')] = '-pedantic'
+        return args
+
+    def has_builtin_define(self, define: str) -> bool:
+        return define in self.defines
+
+    def get_builtin_define(self, define: str) -> T.Optional[str]:
+        if define in self.defines:
+            return self.defines[define]
+        return None
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return gnu_optimization_args[optimization_level]
+
+    def get_pch_suffix(self) -> str:
+        return 'gch'
+
+    def openmp_flags(self) -> T.List[str]:
+        return ['-fopenmp']
+
+    def has_arguments(self, args: T.List[str], env: 'Environment', code: str,
+                      mode: str) -> T.Tuple[bool, bool]:
+        # For some compiler command line arguments, the GNU compilers will
+        # emit a warning on stderr indicating that an option is valid for a
+        # another language, but still complete with exit_success
+        with self._build_wrapper(code, env, args, None, mode) as p:
+            result = p.returncode == 0
+            if self.language in {'cpp', 'objcpp'} and 'is valid for C/ObjC' in p.stderr:
+                result = False
+            if self.language in {'c', 'objc'} and 'is valid for C++/ObjC++' in p.stderr:
+                result = False
+        return result, p.cached
+
+    def get_has_func_attribute_extra_args(self, name: str) -> T.List[str]:
+        # GCC only warns about unknown or ignored attributes, so force an
+        # error.
+        return ['-Werror=attributes']
+
+    def get_prelink_args(self, prelink_name: str, obj_list: T.List[str]) -> T.List[str]:
+        return ['-r', '-o', prelink_name] + obj_list
+
+    def get_lto_compile_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
+        if threads == 0:
+            if mesonlib.version_compare(self.version, '>= 10.0'):
+                return ['-flto=auto']
+            # This matches clang's behavior of using the number of cpus
+            return [f'-flto={multiprocessing.cpu_count()}']
+        elif threads > 0:
+            return [f'-flto={threads}']
+        return super().get_lto_compile_args(threads=threads)
diff --git a/meson/mesonbuild/compilers/mixins/intel.py b/meson/mesonbuild/compilers/mixins/intel.py
new file mode 100644
index 000000000..89f351854
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/intel.py
@@ -0,0 +1,189 @@
+# Copyright 2019 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.
+
+"""Abstractions for the Intel Compiler families.
+
+Intel provides both a posix/gcc-like compiler (ICC) for MacOS and Linux,
+with Meson mixin IntelGnuLikeCompiler.
+For Windows, the Intel msvc-like compiler (ICL) Meson mixin
+is IntelVisualStudioLikeCompiler.
+"""
+
+import os
+import typing as T
+
+from ... import mesonlib
+from ..compilers import CompileCheckMode
+from .gnu import GnuLikeCompiler
+from .visualstudio import VisualStudioLikeCompiler
+
+if T.TYPE_CHECKING:
+    from ...arglist import CompilerArgs
+    from ...dependencies import Dependency
+    from ...environment import Environment
+
+# XXX: avoid circular dependencies
+# TODO: this belongs in a posix compiler class
+# NOTE: the default Intel optimization is -O2, unlike GNU which defaults to -O0.
+# this can be surprising, particularly for debug builds, so we specify the
+# default as -O0.
+# https://software.intel.com/en-us/cpp-compiler-developer-guide-and-reference-o
+# https://software.intel.com/en-us/cpp-compiler-developer-guide-and-reference-g
+# https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-o
+# https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-g
+# https://software.intel.com/en-us/fortran-compiler-developer-guide-and-reference-traceback
+# https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
+
+
+class IntelGnuLikeCompiler(GnuLikeCompiler):
+    """
+    Tested on linux for ICC 14.0.3, 15.0.6, 16.0.4, 17.0.1, 19.0
+    debugoptimized: -g -O2
+    release: -O3
+    minsize: -O2
+    """
+
+    BUILD_ARGS = {
+        'plain': [],
+        'debug': ["-g", "-traceback"],
+        'debugoptimized': ["-g", "-traceback"],
+        'release': [],
+        'minsize': [],
+        'custom': [],
+    }  # type: T.Dict[str, T.List[str]]
+
+    OPTIM_ARGS = {
+        '0': ['-O0'],
+        'g': ['-O0'],
+        '1': ['-O1'],
+        '2': ['-O2'],
+        '3': ['-O3'],
+        's': ['-Os'],
+    }
+
+    def __init__(self) -> None:
+        super().__init__()
+        # As of 19.0.0 ICC doesn't have sanitizer, color, or lto support.
+        #
+        # It does have IPO, which serves much the same purpose as LOT, but
+        # there is an unfortunate rule for using IPO (you can't control the
+        # name of the output file) which break assumptions meson makes
+        self.base_options = {mesonlib.OptionKey(o) for o in [
+            'b_pch', 'b_lundef', 'b_asneeded', 'b_pgo', 'b_coverage',
+            'b_ndebug', 'b_staticpic', 'b_pie']}
+        self.id = 'intel'
+        self.lang_header = 'none'
+
+    def get_pch_suffix(self) -> str:
+        return 'pchi'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        return ['-pch', '-pch_dir', os.path.join(pch_dir), '-x',
+                self.lang_header, '-include', header, '-x', 'none']
+
+    def get_pch_name(self, header_name: str) -> str:
+        return os.path.basename(header_name) + '.' + self.get_pch_suffix()
+
+    def openmp_flags(self) -> T.List[str]:
+        if mesonlib.version_compare(self.version, '>=15.0.0'):
+            return ['-qopenmp']
+        else:
+            return ['-openmp']
+
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
+        extra_args = [
+            '-diag-error', '10006',  # ignoring unknown option
+            '-diag-error', '10148',  # Option not supported
+            '-diag-error', '10155',  # ignoring argument required
+            '-diag-error', '10156',  # ignoring not argument allowed
+            '-diag-error', '10157',  # Ignoring argument of the wrong type
+            '-diag-error', '10158',  # Argument must be separate. Can be hit by trying an option like -foo-bar=foo when -foo=bar is a valid option but -foo-bar isn't
+        ]
+        return super().get_compiler_check_args(mode) + extra_args
+
+    def get_profile_generate_args(self) -> T.List[str]:
+        return ['-prof-gen=threadsafe']
+
+    def get_profile_use_args(self) -> T.List[str]:
+        return ['-prof-use']
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return self.BUILD_ARGS[buildtype]
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return self.OPTIM_ARGS[optimization_level]
+
+    def get_has_func_attribute_extra_args(self, name: str) -> T.List[str]:
+        return ['-diag-error', '1292']
+
+
+class IntelVisualStudioLikeCompiler(VisualStudioLikeCompiler):
+
+    """Abstractions for ICL, the Intel compiler on Windows."""
+
+    BUILD_ARGS = {
+        'plain': [],
+        'debug': ["/Zi", "/traceback"],
+        'debugoptimized': ["/Zi", "/traceback"],
+        'release': [],
+        'minsize': [],
+        'custom': [],
+    }  # type: T.Dict[str, T.List[str]]
+
+    OPTIM_ARGS = {
+        '0': ['/Od'],
+        'g': ['/Od'],
+        '1': ['/O1'],
+        '2': ['/O2'],
+        '3': ['/O3'],
+        's': ['/Os'],
+    }
+
+    def __init__(self, target: str) -> None:
+        super().__init__(target)
+        self.id = 'intel-cl'
+
+    def get_compiler_check_args(self, mode: CompileCheckMode) -> T.List[str]:
+        args = super().get_compiler_check_args(mode)
+        if mode is not CompileCheckMode.LINK:
+            args.extend([
+                '/Qdiag-error:10006',  # ignoring unknown option
+                '/Qdiag-error:10148',  # Option not supported
+                '/Qdiag-error:10155',  # ignoring argument required
+                '/Qdiag-error:10156',  # ignoring not argument allowed
+                '/Qdiag-error:10157',  # Ignoring argument of the wrong type
+                '/Qdiag-error:10158',  # Argument must be separate. Can be hit by trying an option like -foo-bar=foo when -foo=bar is a valid option but -foo-bar isn't
+            ])
+        return args
+
+    def get_toolset_version(self) -> T.Optional[str]:
+        # ICL provides a cl.exe that returns the version of MSVC it tries to
+        # emulate, so we'll get the version from that and pass it to the same
+        # function the real MSVC uses to calculate the toolset version.
+        _, _, err = mesonlib.Popen_safe(['cl.exe'])
+        v1, v2, *_ = mesonlib.search_version(err).split('.')
+        version = int(v1 + v2)
+        return self._calculate_toolset_version(version)
+
+    def openmp_flags(self) -> T.List[str]:
+        return ['/Qopenmp']
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return self.BUILD_ARGS[buildtype]
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return self.OPTIM_ARGS[optimization_level]
+
+    def get_pch_base_name(self, header: str) -> str:
+        return os.path.basename(header)
\ No newline at end of file
diff --git a/meson/mesonbuild/compilers/mixins/islinker.py b/meson/mesonbuild/compilers/mixins/islinker.py
new file mode 100644
index 000000000..4c29f8c0d
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/islinker.py
@@ -0,0 +1,129 @@
+# Copyright 2019 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.
+
+"""Mixins for compilers that *are* linkers.
+
+While many compilers (such as gcc and clang) are used by meson to dispatch
+linker commands and other (like MSVC) are not, a few (such as DMD) actually
+are both the linker and compiler in one binary. This module provides mixin
+classes for those cases.
+"""
+
+import typing as T
+
+from ...mesonlib import EnvironmentException, MesonException, is_windows
+
+if T.TYPE_CHECKING:
+    from ...coredata import KeyedOptionDictType
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+
+class BasicLinkerIsCompilerMixin(Compiler):
+
+    """Provides a baseline of methods that a linker would implement.
+
+    In every case this provides a "no" or "empty" answer. If a compiler
+    implements any of these it needs a different mixin or to override that
+    functionality itself.
+    """
+
+    def sanitizer_link_args(self, value: str) -> T.List[str]:
+        return []
+
+    def get_lto_link_args(self, *, threads: int = 0, mode: str = 'default') -> T.List[str]:
+        return []
+
+    def can_linker_accept_rsp(self) -> bool:
+        return is_windows()
+
+    def get_linker_exelist(self) -> T.List[str]:
+        return self.exelist.copy()
+
+    def get_linker_output_args(self, output: str) -> T.List[str]:
+        return []
+
+    def get_linker_always_args(self) -> T.List[str]:
+        return []
+
+    def get_linker_lib_prefix(self) -> str:
+        return ''
+
+    def get_option_link_args(self, options: 'KeyedOptionDictType') -> T.List[str]:
+        return []
+
+    def has_multi_link_args(self, args: T.List[str], env: 'Environment') -> T.Tuple[bool, bool]:
+        return False, False
+
+    def get_link_debugfile_args(self, targetfile: str) -> T.List[str]:
+        return []
+
+    def get_std_shared_lib_link_args(self) -> T.List[str]:
+        return []
+
+    def get_std_shared_module_args(self, options: 'KeyedOptionDictType') -> T.List[str]:
+        return self.get_std_shared_lib_link_args()
+
+    def get_link_whole_for(self, args: T.List[str]) -> T.List[str]:
+        raise EnvironmentException(f'Linker {self.id} does not support link_whole')
+
+    def get_allow_undefined_link_args(self) -> T.List[str]:
+        raise EnvironmentException(f'Linker {self.id} does not support allow undefined')
+
+    def get_pie_link_args(self) -> T.List[str]:
+        raise EnvironmentException(f'Linker {self.id} does not support position-independent executable')
+
+    def get_undefined_link_args(self) -> T.List[str]:
+        return []
+
+    def get_coverage_link_args(self) -> T.List[str]:
+        return []
+
+    def no_undefined_link_args(self) -> T.List[str]:
+        return []
+
+    def bitcode_args(self) -> T.List[str]:
+        raise MesonException("This linker doesn't support bitcode bundles")
+
+    def get_soname_args(self, env: 'Environment', prefix: str, shlib_name: str,
+                        suffix: str, soversion: str,
+                        darwin_versions: T.Tuple[str, str],
+                        is_shared_module: bool) -> T.List[str]:
+        raise MesonException("This linker doesn't support soname args")
+
+    def build_rpath_args(self, env: 'Environment', build_dir: str, from_dir: str,
+                         rpath_paths: str, build_rpath: str,
+                         install_rpath: str) -> T.Tuple[T.List[str], T.Set[bytes]]:
+        return ([], set())
+
+    def get_asneeded_args(self) -> T.List[str]:
+        return []
+
+    def get_buildtype_linker_args(self, buildtype: str) -> T.List[str]:
+        return []
+
+    def get_link_debugfile_name(self, target: str) -> str:
+        return ''
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    def thread_link_flags(self, env: 'Environment') -> T.List[str]:
+        return []
diff --git a/meson/mesonbuild/compilers/mixins/pgi.py b/meson/mesonbuild/compilers/mixins/pgi.py
new file mode 100644
index 000000000..51de8afa5
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/pgi.py
@@ -0,0 +1,109 @@
+# Copyright 2019 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.
+
+"""Abstractions for the PGI family of compilers."""
+
+import typing as T
+import os
+from pathlib import Path
+
+from ..compilers import clike_debug_args, clike_optimization_args
+from ...mesonlib import OptionKey
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+pgi_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+
+class PGICompiler(Compiler):
+
+    def __init__(self) -> None:
+        self.base_options = {OptionKey('b_pch')}
+        self.id = 'pgi'
+
+        default_warn_args = ['-Minform=inform']
+        self.warn_args = {'0': [],
+                          '1': default_warn_args,
+                          '2': default_warn_args,
+                          '3': default_warn_args
+        }  # type: T.Dict[str, T.List[str]]
+
+    def get_module_incdir_args(self) -> T.Tuple[str]:
+        return ('-module', )
+
+    def get_no_warn_args(self) -> T.List[str]:
+        return ['-silent']
+
+    def gen_import_library_args(self, implibname: str) -> T.List[str]:
+        return []
+
+    def get_pic_args(self) -> T.List[str]:
+        # PGI -fPIC is Linux only.
+        if self.info.is_linux():
+            return ['-fPIC']
+        return []
+
+    def openmp_flags(self) -> T.List[str]:
+        return ['-mp']
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return pgi_buildtype_args[buildtype]
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return clike_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return clike_debug_args[is_debug]
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:2] == '-I' or i[:2] == '-L':
+                parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))
+        return parameter_list
+
+    def get_always_args(self) -> T.List[str]:
+        return []
+
+    def get_pch_suffix(self) -> str:
+        # PGI defaults to .pch suffix for PCH on Linux and Windows with --pch option
+        return 'pch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        # PGI supports PCH for C++ only.
+        hdr = Path(pch_dir).resolve().parent / header
+        if self.language == 'cpp':
+            return ['--pch',
+                    '--pch_dir', str(hdr.parent),
+                    f'-I{hdr.parent}']
+        else:
+            return []
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        # PGI cannot accept -pthread, it's already threaded
+        return []
diff --git a/meson/mesonbuild/compilers/mixins/visualstudio.py b/meson/mesonbuild/compilers/mixins/visualstudio.py
new file mode 100644
index 000000000..e911f64f4
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/visualstudio.py
@@ -0,0 +1,428 @@
+# Copyright 2019 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.
+
+"""Abstractions to simplify compilers that implement an MSVC compatible
+interface.
+"""
+
+import abc
+import os
+import typing as T
+
+from ... import arglist
+from ... import mesonlib
+from ... import mlog
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from .clike import CLikeCompiler as Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+vs32_instruction_set_args = {
+    'mmx': ['/arch:SSE'], # There does not seem to be a flag just for MMX
+    'sse': ['/arch:SSE'],
+    'sse2': ['/arch:SSE2'],
+    'sse3': ['/arch:AVX'], # VS leaped from SSE2 directly to AVX.
+    'sse41': ['/arch:AVX'],
+    'sse42': ['/arch:AVX'],
+    'avx': ['/arch:AVX'],
+    'avx2': ['/arch:AVX2'],
+    'neon': None,
+}  # T.Dicst[str, T.Optional[T.List[str]]]
+
+# The 64 bit compiler defaults to /arch:avx.
+vs64_instruction_set_args = {
+    'mmx': ['/arch:AVX'],
+    'sse': ['/arch:AVX'],
+    'sse2': ['/arch:AVX'],
+    'sse3': ['/arch:AVX'],
+    'ssse3': ['/arch:AVX'],
+    'sse41': ['/arch:AVX'],
+    'sse42': ['/arch:AVX'],
+    'avx': ['/arch:AVX'],
+    'avx2': ['/arch:AVX2'],
+    'neon': None,
+}  # T.Dicst[str, T.Optional[T.List[str]]]
+
+msvc_optimization_args = {
+    '0': ['/Od'],
+    'g': [], # No specific flag to optimize debugging, /Zi or /ZI will create debug information
+    '1': ['/O1'],
+    '2': ['/O2'],
+    '3': ['/O2', '/Gw'],
+    's': ['/O1', '/Gw'],
+}  # type: T.Dict[str, T.List[str]]
+
+msvc_debug_args = {
+    False: [],
+    True: ['/Zi']
+}  # type: T.Dict[bool, T.List[str]]
+
+
+class VisualStudioLikeCompiler(Compiler, metaclass=abc.ABCMeta):
+
+    """A common interface for all compilers implementing an MSVC-style
+    interface.
+
+    A number of compilers attempt to mimic MSVC, with varying levels of
+    success, such as Clang-CL and ICL (the Intel C/C++ Compiler for Windows).
+    This class implements as much common logic as possible.
+    """
+
+    std_warn_args = ['/W3']
+    std_opt_args = ['/O2']
+    ignore_libs = arglist.UNIXY_COMPILER_INTERNAL_LIBS + ['execinfo']
+    internal_libs = []  # type: T.List[str]
+
+    crt_args = {
+        'none': [],
+        'md': ['/MD'],
+        'mdd': ['/MDd'],
+        'mt': ['/MT'],
+        'mtd': ['/MTd'],
+    }  # type: T.Dict[str, T.List[str]]
+
+    # /showIncludes is needed for build dependency tracking in Ninja
+    # See: https://ninja-build.org/manual.html#_deps
+    always_args = ['/nologo', '/showIncludes']
+    warn_args = {
+        '0': [],
+        '1': ['/W2'],
+        '2': ['/W3'],
+        '3': ['/W4'],
+    }  # type: T.Dict[str, T.List[str]]
+
+    INVOKES_LINKER = False
+
+    def __init__(self, target: str):
+        self.base_options = {mesonlib.OptionKey(o) for o in ['b_pch', 'b_ndebug', 'b_vscrt']} # FIXME add lto, pgo and the like
+        self.target = target
+        self.is_64 = ('x64' in target) or ('x86_64' in target)
+        # do some canonicalization of target machine
+        if 'x86_64' in target:
+            self.machine = 'x64'
+        elif '86' in target:
+            self.machine = 'x86'
+        elif 'aarch64' in target:
+            self.machine = 'arm64'
+        elif 'arm' in target:
+            self.machine = 'arm'
+        else:
+            self.machine = target
+        if mesonlib.version_compare(self.version, '>=19.28.29910'): # VS 16.9.0 includes cl 19.28.29910
+            self.base_options.add(mesonlib.OptionKey('b_sanitize'))
+        assert self.linker is not None
+        self.linker.machine = self.machine
+
+    # Override CCompiler.get_always_args
+    def get_always_args(self) -> T.List[str]:
+        return self.always_args
+
+    def get_pch_suffix(self) -> str:
+        return 'pch'
+
+    def get_pch_name(self, header: str) -> str:
+        chopped = os.path.basename(header).split('.')[:-1]
+        chopped.append(self.get_pch_suffix())
+        pchname = '.'.join(chopped)
+        return pchname
+
+    def get_pch_base_name(self, header: str) -> str:
+        # This needs to be implemented by inherting classes
+        raise NotImplementedError
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        base = self.get_pch_base_name(header)
+        pchname = self.get_pch_name(header)
+        return ['/FI' + base, '/Yu' + base, '/Fp' + os.path.join(pch_dir, pchname)]
+
+    def get_preprocess_only_args(self) -> T.List[str]:
+        return ['/EP']
+
+    def get_compile_only_args(self) -> T.List[str]:
+        return ['/c']
+
+    def get_no_optimization_args(self) -> T.List[str]:
+        return ['/Od','/Oi-']
+
+    def sanitizer_compile_args(self, value: str) -> T.List[str]:
+        if value == 'none':
+            return []
+        if value != 'address':
+            raise mesonlib.MesonException('VS only supports address sanitizer at the moment.')
+        return ['/fsanitize=address']
+
+    def get_output_args(self, target: str) -> T.List[str]:
+        if target.endswith('.exe'):
+            return ['/Fe' + target]
+        return ['/Fo' + target]
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return []
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return msvc_debug_args[is_debug]
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        args = msvc_optimization_args[optimization_level]
+        if mesonlib.version_compare(self.version, '<18.0'):
+            args = [arg for arg in args if arg != '/Gw']
+        return args
+
+    def linker_to_compiler_args(self, args: T.List[str]) -> T.List[str]:
+        return ['/link'] + args
+
+    def get_pic_args(self) -> T.List[str]:
+        return [] # PIC is handled by the loader on Windows
+
+    def gen_vs_module_defs_args(self, defsfile: str) -> T.List[str]:
+        if not isinstance(defsfile, str):
+            raise RuntimeError('Module definitions file should be str')
+        # With MSVC, DLLs only export symbols that are explicitly exported,
+        # so if a module defs file is specified, we use that to export symbols
+        return ['/DEF:' + defsfile]
+
+    def gen_pch_args(self, header: str, source: str, pchname: str) -> T.Tuple[str, T.List[str]]:
+        objname = os.path.splitext(pchname)[0] + '.obj'
+        return objname, ['/Yc' + header, '/Fp' + pchname, '/Fo' + objname]
+
+    def openmp_flags(self) -> T.List[str]:
+        return ['/openmp']
+
+    def openmp_link_flags(self) -> T.List[str]:
+        return []
+
+    # FIXME, no idea what these should be.
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    @classmethod
+    def unix_args_to_native(cls, args: T.List[str]) -> T.List[str]:
+        result = []
+        for i in args:
+            # -mms-bitfields is specific to MinGW-GCC
+            # -pthread is only valid for GCC
+            if i in ('-mms-bitfields', '-pthread'):
+                continue
+            if i.startswith('-LIBPATH:'):
+                i = '/LIBPATH:' + i[9:]
+            elif i.startswith('-L'):
+                i = '/LIBPATH:' + i[2:]
+            # Translate GNU-style -lfoo library name to the import library
+            elif i.startswith('-l'):
+                name = i[2:]
+                if name in cls.ignore_libs:
+                    # With MSVC, these are provided by the C runtime which is
+                    # linked in by default
+                    continue
+                else:
+                    i = name + '.lib'
+            elif i.startswith('-isystem'):
+                # just use /I for -isystem system include path s
+                if i.startswith('-isystem='):
+                    i = '/I' + i[9:]
+                else:
+                    i = '/I' + i[8:]
+            elif i.startswith('-idirafter'):
+                # same as -isystem, but appends the path instead
+                if i.startswith('-idirafter='):
+                    i = '/I' + i[11:]
+                else:
+                    i = '/I' + i[10:]
+            # -pthread in link flags is only used on Linux
+            elif i == '-pthread':
+                continue
+            result.append(i)
+        return result
+
+    @classmethod
+    def native_args_to_unix(cls, args: T.List[str]) -> T.List[str]:
+        result = []
+        for arg in args:
+            if arg.startswith(('/LIBPATH:', '-LIBPATH:')):
+                result.append('-L' + arg[9:])
+            elif arg.endswith(('.a', '.lib')) and not os.path.isabs(arg):
+                result.append('-l' + arg)
+            else:
+                result.append(arg)
+        return result
+
+    def get_werror_args(self) -> T.List[str]:
+        return ['/WX']
+
+    def get_include_args(self, path: str, is_system: bool) -> T.List[str]:
+        if path == '':
+            path = '.'
+        # msvc does not have a concept of system header dirs.
+        return ['-I' + path]
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:2] == '-I' or i[:2] == '/I':
+                parameter_list[idx] = i[:2] + os.path.normpath(os.path.join(build_dir, i[2:]))
+            elif i[:9] == '/LIBPATH:':
+                parameter_list[idx] = i[:9] + os.path.normpath(os.path.join(build_dir, i[9:]))
+
+        return parameter_list
+
+    # Visual Studio is special. It ignores some arguments it does not
+    # understand and you can't tell it to error out on those.
+    # http://stackoverflow.com/questions/15259720/how-can-i-make-the-microsoft-c-compiler-treat-unknown-flags-as-errors-rather-t
+    def has_arguments(self, args: T.List[str], env: 'Environment', code: str, mode: str) -> T.Tuple[bool, bool]:
+        warning_text = '4044' if mode == 'link' else '9002'
+        with self._build_wrapper(code, env, extra_args=args, mode=mode) as p:
+            if p.returncode != 0:
+                return False, p.cached
+            return not(warning_text in p.stderr or warning_text in p.stdout), p.cached
+
+    def get_compile_debugfile_args(self, rel_obj: str, pch: bool = False) -> T.List[str]:
+        pdbarr = rel_obj.split('.')[:-1]
+        pdbarr += ['pdb']
+        args = ['/Fd' + '.'.join(pdbarr)]
+        return args
+
+    def get_instruction_set_args(self, instruction_set: str) -> T.Optional[T.List[str]]:
+        if self.is_64:
+            return vs64_instruction_set_args.get(instruction_set, None)
+        return vs32_instruction_set_args.get(instruction_set, None)
+
+    def _calculate_toolset_version(self, version: int) -> T.Optional[str]:
+        if version < 1310:
+            return '7.0'
+        elif version < 1400:
+            return '7.1' # (Visual Studio 2003)
+        elif version < 1500:
+            return '8.0' # (Visual Studio 2005)
+        elif version < 1600:
+            return '9.0' # (Visual Studio 2008)
+        elif version < 1700:
+            return '10.0' # (Visual Studio 2010)
+        elif version < 1800:
+            return '11.0' # (Visual Studio 2012)
+        elif version < 1900:
+            return '12.0' # (Visual Studio 2013)
+        elif version < 1910:
+            return '14.0' # (Visual Studio 2015)
+        elif version < 1920:
+            return '14.1' # (Visual Studio 2017)
+        elif version < 1930:
+            return '14.2' # (Visual Studio 2019)
+        mlog.warning(f'Could not find toolset for version {self.version!r}')
+        return None
+
+    def get_toolset_version(self) -> T.Optional[str]:
+        # See boost/config/compiler/visualc.cpp for up to date mapping
+        try:
+            version = int(''.join(self.version.split('.')[0:2]))
+        except ValueError:
+            return None
+        return self._calculate_toolset_version(version)
+
+    def get_default_include_dirs(self) -> T.List[str]:
+        if 'INCLUDE' not in os.environ:
+            return []
+        return os.environ['INCLUDE'].split(os.pathsep)
+
+    def get_crt_compile_args(self, crt_val: str, buildtype: str) -> T.List[str]:
+        if crt_val in self.crt_args:
+            return self.crt_args[crt_val]
+        assert(crt_val in ['from_buildtype', 'static_from_buildtype'])
+        dbg = 'mdd'
+        rel = 'md'
+        if crt_val == 'static_from_buildtype':
+            dbg = 'mtd'
+            rel = 'mt'
+        # Match what build type flags used to do.
+        if buildtype == 'plain':
+            return []
+        elif buildtype == 'debug':
+            return self.crt_args[dbg]
+        elif buildtype == 'debugoptimized':
+            return self.crt_args[rel]
+        elif buildtype == 'release':
+            return self.crt_args[rel]
+        elif buildtype == 'minsize':
+            return self.crt_args[rel]
+        else:
+            assert(buildtype == 'custom')
+            raise mesonlib.EnvironmentException('Requested C runtime based on buildtype, but buildtype is "custom".')
+
+    def has_func_attribute(self, name: str, env: 'Environment') -> T.Tuple[bool, bool]:
+        # MSVC doesn't have __attribute__ like Clang and GCC do, so just return
+        # false without compiling anything
+        return name in ['dllimport', 'dllexport'], False
+
+    def get_argument_syntax(self) -> str:
+        return 'msvc'
+
+
+class MSVCCompiler(VisualStudioLikeCompiler):
+
+    """Spcific to the Microsoft Compilers."""
+
+    def __init__(self, target: str):
+        super().__init__(target)
+        self.id = 'msvc'
+
+    def get_compile_debugfile_args(self, rel_obj: str, pch: bool = False) -> T.List[str]:
+        args = super().get_compile_debugfile_args(rel_obj, pch)
+        # When generating a PDB file with PCH, all compile commands write
+        # to the same PDB file. Hence, we need to serialize the PDB
+        # writes using /FS since we do parallel builds. This slows down the
+        # build obviously, which is why we only do this when PCH is on.
+        # This was added in Visual Studio 2013 (MSVC 18.0). Before that it was
+        # always on: https://msdn.microsoft.com/en-us/library/dn502518.aspx
+        if pch and mesonlib.version_compare(self.version, '>=18.0'):
+            args = ['/FS'] + args
+        return args
+
+    def get_instruction_set_args(self, instruction_set: str) -> T.Optional[T.List[str]]:
+        if self.version.split('.')[0] == '16' and instruction_set == 'avx':
+            # VS documentation says that this exists and should work, but
+            # it does not. The headers do not contain AVX intrinsics
+            # and they can not be called.
+            return None
+        return super().get_instruction_set_args(instruction_set)
+
+    def get_pch_base_name(self, header: str) -> str:
+        return os.path.basename(header)
+
+
+class ClangClCompiler(VisualStudioLikeCompiler):
+
+    """Spcific to Clang-CL."""
+
+    def __init__(self, target: str):
+        super().__init__(target)
+        self.id = 'clang-cl'
+
+        # Assembly
+        self.can_compile_suffixes.add('s')
+
+    def has_arguments(self, args: T.List[str], env: 'Environment', code: str, mode: str) -> T.Tuple[bool, bool]:
+        if mode != 'link':
+            args = args + ['-Werror=unknown-argument']
+        return super().has_arguments(args, env, code, mode)
+
+    def get_toolset_version(self) -> T.Optional[str]:
+        # XXX: what is the right thing to do here?
+        return '14.1'
+
+    def get_pch_base_name(self, header: str) -> str:
+        return header
diff --git a/meson/mesonbuild/compilers/mixins/xc16.py b/meson/mesonbuild/compilers/mixins/xc16.py
new file mode 100644
index 000000000..77c4690ff
--- /dev/null
+++ b/meson/mesonbuild/compilers/mixins/xc16.py
@@ -0,0 +1,127 @@
+# Copyright 2012-2019 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.
+
+"""Representations specific to the Microchip XC16 C compiler family."""
+
+import os
+import typing as T
+
+from ...mesonlib import EnvironmentException
+
+if T.TYPE_CHECKING:
+    from ...environment import Environment
+    from ...compilers.compilers import Compiler
+else:
+    # This is a bit clever, for mypy we pretend that these mixins descend from
+    # Compiler, so we get all of the methods and attributes defined for us, but
+    # for runtime we make them descend from object (which all classes normally
+    # do). This gives up DRYer type checking, with no runtime impact
+    Compiler = object
+
+xc16_buildtype_args = {
+    'plain': [],
+    'debug': [],
+    'debugoptimized': [],
+    'release': [],
+    'minsize': [],
+    'custom': [],
+}  # type: T.Dict[str, T.List[str]]
+
+xc16_optimization_args = {
+    '0': ['-O0'],
+    'g': ['-O0'],
+    '1': ['-O1'],
+    '2': ['-O2'],
+    '3': ['-O3'],
+    's': ['-Os']
+}  # type: T.Dict[str, T.List[str]]
+
+xc16_debug_args = {
+    False: [],
+    True: []
+}  # type: T.Dict[bool, T.List[str]]
+
+
+class Xc16Compiler(Compiler):
+
+    def __init__(self) -> None:
+        if not self.is_cross:
+            raise EnvironmentException('xc16 supports only cross-compilation.')
+        self.id = 'xc16'
+        # Assembly
+        self.can_compile_suffixes.add('s')
+        default_warn_args = []  # type: T.List[str]
+        self.warn_args = {'0': [],
+                          '1': default_warn_args,
+                          '2': default_warn_args + [],
+                          '3': default_warn_args + []}  # type: T.Dict[str, T.List[str]]
+
+    def get_always_args(self) -> T.List[str]:
+        return []
+
+    def get_pic_args(self) -> T.List[str]:
+        # PIC support is not enabled by default for xc16,
+        # if users want to use it, they need to add the required arguments explicitly
+        return []
+
+    def get_buildtype_args(self, buildtype: str) -> T.List[str]:
+        return xc16_buildtype_args[buildtype]
+
+    def get_pch_suffix(self) -> str:
+        return 'pch'
+
+    def get_pch_use_args(self, pch_dir: str, header: str) -> T.List[str]:
+        return []
+
+    def thread_flags(self, env: 'Environment') -> T.List[str]:
+        return []
+
+    def get_coverage_args(self) -> T.List[str]:
+        return []
+
+    def get_no_stdinc_args(self) -> T.List[str]:
+        return ['-nostdinc']
+
+    def get_no_stdlib_link_args(self) -> T.List[str]:
+        return ['--nostdlib']
+
+    def get_optimization_args(self, optimization_level: str) -> T.List[str]:
+        return xc16_optimization_args[optimization_level]
+
+    def get_debug_args(self, is_debug: bool) -> T.List[str]:
+        return xc16_debug_args[is_debug]
+
+    @classmethod
+    def unix_args_to_native(cls, args: T.List[str]) -> T.List[str]:
+        result = []
+        for i in args:
+            if i.startswith('-D'):
+                i = '-D' + i[2:]
+            if i.startswith('-I'):
+                i = '-I' + i[2:]
+            if i.startswith('-Wl,-rpath='):
+                continue
+            elif i == '--print-search-dirs':
+                continue
+            elif i.startswith('-L'):
+                continue
+            result.append(i)
+        return result
+
+    def compute_parameters_with_absolute_paths(self, parameter_list: T.List[str], build_dir: str) -> T.List[str]:
+        for idx, i in enumerate(parameter_list):
+            if i[:9] == '-I':
+                parameter_list[idx] = i[:9] + os.path.normpath(os.path.join(build_dir, i[9:]))
+
+        return parameter_list