Merge pull request #4250 from jon-turney/windows-clang-cl

Add support for clang-cl on Windows

31 files changed, 217 insertions, 128 deletions

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 8c36abd..5f7e3c4 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -44,6 +44,10 @@ jobs:
           arch: x64
           compiler: msvc2017
           backend: vs2017
+        clangclx64ninja:
+          arch: x64
+          compiler: clang-cl
+          backend: ninja
 
   steps:
   - template: ci/azure-steps.yml
diff --git a/ci/azure-steps.yml b/ci/azure-steps.yml
index 5c4a058..6303761 100644
--- a/ci/azure-steps.yml
+++ b/ci/azure-steps.yml
@@ -48,13 +48,34 @@ steps:
      # add downloads to PATH
      $env:Path = "$env:SYSTEM_WORKFOLDER;$env:Path"
 
+     $origPath = $env:Path
      # import visual studio variables
+     if ($env:compiler -eq 'msvc2015') {
+       $vsver = $env:compiler.Replace('msvc', '')
+     } else {
+       $vsver = '2017'
+     }
      Set-PSRepository -Name PSGallery -InstallationPolicy Trusted
      Install-Module Pscx -Scope CurrentUser -AllowClobber
      Install-Module VSSetup -Scope CurrentUser
-     $vsver = $env:compiler.Replace('msvc', '')
      Import-VisualStudioVars -VisualStudioVersion $vsver -Architecture $(arch)
 
+     if ($env:compiler -eq 'clang-cl') {
+       # drop visual studio from PATH
+       # (but leave INCLUDE, LIB and WindowsSdkDir environment variables set)
+       $env:Path = $origPath
+
+       # install llvm for clang-cl builds
+       DownloadFile -Source 'http://releases.llvm.org/7.0.0/LLVM-7.0.0-win64.exe' -Destination LLVM-7.0.0-win64.exe
+       Start-Process .\LLVM-7.0.0-win64.exe -ArgumentList '/S' -Wait
+       $env:Path = "C:\Program Files\LLVM\bin;$env:Path"
+       $env:CC = "clang-cl"
+       $env:CXX = "clang-cl"
+
+       # and use Windows SDK tools
+       $env:Path = "$env:WindowsSdkDir\bin\$env:Arch;$env:Path"
+     }
+
      # add .NET framework tools to path for resgen for C# tests
      # (always use 32-bit tool, as there doesn't seem to be a 64-bit tool)
      if ((Get-Command "resgen.exe" -ErrorAction SilentlyContinue) -eq $null) {
diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index 7dc1b83..370e35b 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -23,7 +23,7 @@ import subprocess
 from ..mesonlib import MesonException, OrderedSet
 from ..mesonlib import classify_unity_sources
 from ..mesonlib import File
-from ..compilers import CompilerArgs
+from ..compilers import CompilerArgs, VisualStudioCCompiler
 from collections import OrderedDict
 import shlex
 from functools import lru_cache
@@ -491,7 +491,7 @@ class Backend:
             return args
         extra_args = []
         # Compiler-specific escaping is needed for -D args but not for any others
-        if compiler.get_id() == 'msvc':
+        if isinstance(compiler, VisualStudioCCompiler):
             # MSVC needs escaping when a -D argument ends in \ or \"
             for arg in args:
                 if arg.startswith('-D') or arg.startswith('/D'):
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 229980d..28c6480 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -29,7 +29,7 @@ from .. import build
 from .. import mlog
 from .. import dependencies
 from .. import compilers
-from ..compilers import CompilerArgs, CCompiler
+from ..compilers import CompilerArgs, CCompiler, VisualStudioCCompiler
 from ..linkers import ArLinker
 from ..mesonlib import File, MesonException, OrderedSet
 from ..mesonlib import get_compiler_for_source, has_path_sep
@@ -169,7 +169,7 @@ class NinjaBackend(backends.Backend):
         Detect the search prefix to use.'''
         for compiler in self.build.compilers.values():
             # Have to detect the dependency format
-            if compiler.id == 'msvc':
+            if isinstance(compiler, VisualStudioCCompiler):
                 break
         else:
             # None of our compilers are MSVC, we're done.
@@ -185,7 +185,8 @@ int dummy;
         # and locale dependent. Any attempt at converting it to
         # Python strings leads to failure. We _must_ do this detection
         # in raw byte mode and write the result in raw bytes.
-        pc = subprocess.Popen(['cl', '/showIncludes', '/c', 'incdetect.c'],
+        pc = subprocess.Popen([compiler.get_exelist(),
+                               '/showIncludes', '/c', 'incdetect.c'],
                               cwd=self.environment.get_scratch_dir(),
                               stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         (stdo, _) = pc.communicate()
@@ -195,7 +196,7 @@ int dummy;
         # different locales have different messages with a different
         # number of colons. Match up to the the drive name 'd:\'.
         matchre = re.compile(rb"^(.*\s)[a-zA-Z]:\\.*stdio.h$")
-        for line in stdo.split(b'\r\n'):
+        for line in re.split(rb'\r?\n', stdo):
             match = matchre.match(line)
             if match:
                 with open(tempfilename, 'ab') as binfile:
@@ -1604,7 +1605,7 @@ rule FORTRAN_DEP_HACK%s
             compile_only_args=' '.join(compiler.get_compile_only_args())
         )
         description = ' description = Compiling %s object $out.\n' % compiler.get_display_language()
-        if compiler.get_id() == 'msvc':
+        if isinstance(compiler, VisualStudioCCompiler):
             deps = ' deps = msvc\n'
         else:
             deps = ' deps = gcc\n'
@@ -1636,7 +1637,7 @@ rule FORTRAN_DEP_HACK%s
             if d != '$out' and d != '$in':
                 d = quote_func(d)
             quoted_depargs.append(d)
-        if compiler.get_id() == 'msvc':
+        if isinstance(compiler, VisualStudioCCompiler):
             output = ''
         else:
             output = ' '.join(compiler.get_output_args('$out'))
@@ -1648,7 +1649,7 @@ rule FORTRAN_DEP_HACK%s
             compile_only_args=' '.join(compiler.get_compile_only_args())
         )
         description = ' description = Precompiling header %s.\n' % '$in'
-        if compiler.get_id() == 'msvc':
+        if isinstance(compiler, VisualStudioCCompiler):
             deps = ' deps = msvc\n'
         else:
             deps = ' deps = gcc\n'
@@ -1839,7 +1840,7 @@ rule FORTRAN_DEP_HACK%s
         return compiler.get_no_stdinc_args()
 
     def get_compile_debugfile_args(self, compiler, target, objfile):
-        if compiler.id != 'msvc':
+        if not isinstance(compiler, VisualStudioCCompiler):
             return []
         # The way MSVC uses PDB files is documented exactly nowhere so
         # the following is what we have been able to decipher via
@@ -2203,7 +2204,7 @@ rule FORTRAN_DEP_HACK%s
                       ''.format(target.get_basename())
                 raise InvalidArguments(msg)
             compiler = target.compilers[lang]
-            if compiler.id == 'msvc':
+            if isinstance(compiler, VisualStudioCCompiler):
                 src = os.path.join(self.build_to_src, target.get_source_subdir(), pch[-1])
                 (commands, dep, dst, objs) = self.generate_msvc_pch_command(target, compiler, pch)
                 extradep = os.path.join(self.build_to_src, target.get_source_subdir(), pch[0])
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index df67c8e..8bb49c0 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -1168,7 +1168,7 @@ You probably should put it in link_with instead.''')
         '''
         linker, _ = self.get_clink_dynamic_linker_and_stdlibs()
         # Mixing many languages with MSVC is not supported yet so ignore stdlibs.
-        if linker and linker.get_id() in ['msvc', 'llvm', 'dmd']:
+        if linker and linker.get_id() in ['msvc', 'clang-cl', 'llvm', 'dmd']:
             return True
         return False
 
diff --git a/mesonbuild/compilers/__init__.py b/mesonbuild/compilers/__init__.py
index 677301e..7050b0c 100644
--- a/mesonbuild/compilers/__init__.py
+++ b/mesonbuild/compilers/__init__.py
@@ -45,6 +45,8 @@ __all__ = [
     'ClangCPPCompiler',
     'ClangObjCCompiler',
     'ClangObjCPPCompiler',
+    'ClangClCCompiler',
+    'ClangClCPPCompiler',
     'CompilerArgs',
     'CPPCompiler',
     'DCompiler',
@@ -114,6 +116,7 @@ from .c import (
     ArmCCompiler,
     ArmclangCCompiler,
     ClangCCompiler,
+    ClangClCCompiler,
     GnuCCompiler,
     ElbrusCCompiler,
     IntelCCompiler,
@@ -124,6 +127,7 @@ from .cpp import (
     ArmCPPCompiler,
     ArmclangCPPCompiler,
     ClangCPPCompiler,
+    ClangClCPPCompiler,
     GnuCPPCompiler,
     ElbrusCPPCompiler,
     IntelCPPCompiler,
diff --git a/mesonbuild/compilers/c.py b/mesonbuild/compilers/c.py
index 9b24e85..35c71df 100644
--- a/mesonbuild/compilers/c.py
+++ b/mesonbuild/compilers/c.py
@@ -170,7 +170,7 @@ class CCompiler(Compiler):
             else:
                 # GNU ld and LLVM lld
                 return ['-Wl,--allow-shlib-undefined']
-        elif self.id == 'msvc':
+        elif isinstance(self, VisualStudioCCompiler):
             # link.exe
             return ['/FORCE:UNRESOLVED']
         # FIXME: implement other linkers
@@ -392,6 +392,8 @@ class CCompiler(Compiler):
         return self.compiles(t.format(**fargs), env, extra_args, dependencies)
 
     def _get_compiler_check_args(self, env, extra_args, dependencies, mode='compile'):
+        if callable(extra_args):
+            extra_args = extra_args(mode)
         if extra_args is None:
             extra_args = []
         elif isinstance(extra_args, str):
@@ -890,7 +892,7 @@ class CCompiler(Compiler):
         stlibext = ['a']
         # We've always allowed libname to be both `foo` and `libfoo`,
         # and now people depend on it
-        if strict and self.id != 'msvc': # lib prefix is not usually used with msvc
+        if strict and not isinstance(self, VisualStudioCCompiler): # lib prefix is not usually used with msvc
             prefixes = ['lib']
         else:
             prefixes = ['lib', '']
@@ -900,7 +902,7 @@ class CCompiler(Compiler):
         elif for_windows(env.is_cross_build(), env):
             # 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 self.id == 'msvc':
+            if isinstance(self, VisualStudioCCompiler):
                 shlibext = ['lib']
             else:
                 shlibext = ['dll.a', 'lib', 'dll']
@@ -1296,7 +1298,7 @@ class VisualStudioCCompiler(CCompiler):
 
     def get_buildtype_args(self, buildtype):
         args = compilers.msvc_buildtype_args[buildtype]
-        if version_compare(self.version, '<18.0'):
+        if self.id == 'msvc' and version_compare(self.version, '<18.0'):
             args = [arg for arg in args if arg != '/Gw']
         return args
 
@@ -1314,6 +1316,8 @@ class VisualStudioCCompiler(CCompiler):
 
     def get_pch_use_args(self, pch_dir, header):
         base = os.path.basename(header)
+        if self.id == 'clang-cl':
+            base = header
         pchname = self.get_pch_name(header)
         return ['/FI' + base, '/Yu' + base, '/Fp' + os.path.join(pch_dir, pchname)]
 
@@ -1341,7 +1345,12 @@ class VisualStudioCCompiler(CCompiler):
         return []
 
     def get_linker_exelist(self):
-        return ['link'] # FIXME, should have same path as compiler.
+        # FIXME, should have same path as compiler.
+        # FIXME, should be controllable via cross-file.
+        if self.id == 'clang-cl':
+            return ['lld-link']
+        else:
+            return ['link']
 
     def get_linker_always_args(self):
         return ['/nologo']
@@ -1449,6 +1458,8 @@ class VisualStudioCCompiler(CCompiler):
     # 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, env, code, mode):
         warning_text = '4044' if mode == 'link' else '9002'
+        if self.id == 'clang-cl' and mode != 'link':
+            args = args + ['-Werror=unknown-argument']
         with self._build_wrapper(code, env, extra_args=args, mode=mode) as p:
             if p.returncode != 0:
                 return False
@@ -1464,7 +1475,7 @@ class VisualStudioCCompiler(CCompiler):
         # 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 version_compare(self.version, '>=18.0'):
+        if pch and self.id == 'msvc' and version_compare(self.version, '>=18.0'):
             args = ['/FS'] + args
         return args
 
@@ -1481,7 +1492,7 @@ class VisualStudioCCompiler(CCompiler):
     def get_instruction_set_args(self, instruction_set):
         if self.is_64:
             return vs64_instruction_set_args.get(instruction_set, None)
-        if self.version.split('.')[0] == '16' and instruction_set == 'avx':
+        if self.id == 'msvc' and 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 the can not be called.
@@ -1489,6 +1500,10 @@ class VisualStudioCCompiler(CCompiler):
         return vs32_instruction_set_args.get(instruction_set, None)
 
     def get_toolset_version(self):
+        if self.id == 'clang-cl':
+            # I have no idea
+            return '14.1'
+
         # See boost/config/compiler/visualc.cpp for up to date mapping
         try:
             version = int(''.join(self.version.split('.')[0:2]))
@@ -1546,6 +1561,10 @@ class VisualStudioCCompiler(CCompiler):
     def get_argument_syntax(self):
         return 'msvc'
 
+class ClangClCCompiler(VisualStudioCCompiler):
+    def __init__(self, exelist, version, is_cross, exe_wrap, is_64):
+        super().__init__(exelist, version, is_cross, exe_wrap, is_64)
+        self.id = 'clang-cl'
 
 class ArmCCompiler(ArmCompiler, CCompiler):
     def __init__(self, exelist, version, compiler_type, is_cross, exe_wrapper=None, **kwargs):
diff --git a/mesonbuild/compilers/cpp.py b/mesonbuild/compilers/cpp.py
index 9dc2876..65a1033 100644
--- a/mesonbuild/compilers/cpp.py
+++ b/mesonbuild/compilers/cpp.py
@@ -19,7 +19,7 @@ from .. import coredata
 from .. import mlog
 from ..mesonlib import MesonException, version_compare
 
-from .c import CCompiler, VisualStudioCCompiler
+from .c import CCompiler, VisualStudioCCompiler, ClangClCCompiler
 from .compilers import (
     CompilerType,
     gnu_winlibs,
@@ -310,12 +310,15 @@ class VisualStudioCPPCompiler(VisualStudioCCompiler, CPPCompiler):
 
     def get_options(self):
         cpp_stds = ['none', 'c++11', 'vc++11']
-        # Visual Studio 2015 and later
-        if version_compare(self.version, '>=19'):
-            cpp_stds.extend(['c++14', 'vc++14', 'c++latest', 'vc++latest'])
-        # Visual Studio 2017 and later
-        if version_compare(self.version, '>=19.11'):
-            cpp_stds.extend(['c++17', 'vc++17'])
+        if self.id == 'clang-cl':
+            cpp_stds.extend(['c++14', 'vc++14', 'c++17', 'vc++17', 'c++latest'])
+        else:
+            # Visual Studio 2015 and later
+            if version_compare(self.version, '>=19'):
+                cpp_stds.extend(['c++14', 'vc++14', 'c++latest', 'vc++latest'])
+            # Visual Studio 2017 and later
+            if version_compare(self.version, '>=19.11'):
+                cpp_stds.extend(['c++17', 'vc++17'])
 
         opts = CPPCompiler.get_options(self)
         opts.update({'cpp_eh': coredata.UserComboOption('cpp_eh',
@@ -356,7 +359,7 @@ class VisualStudioCPPCompiler(VisualStudioCCompiler, CPPCompiler):
             # which means setting the C++ standard version to C++14, in compilers that support it
             # (i.e., after VS2015U3)
             # if one is using anything before that point, one cannot set the standard.
-            if version_compare(self.version, '>=19.00.24210'):
+            if self.id == 'clang-cl' or version_compare(self.version, '>=19.00.24210'):
                 mlog.warning('MSVC does not support C++11; '
                              'attempting best effort; setting the standard to C++14')
                 args.append('/std:c++14')
@@ -378,6 +381,10 @@ class VisualStudioCPPCompiler(VisualStudioCCompiler, CPPCompiler):
         # so just use the plain C args.
         return VisualStudioCCompiler.get_compiler_check_args(self)
 
+class ClangClCPPCompiler(VisualStudioCPPCompiler, ClangClCCompiler):
+    def __init__(self, exelist, version, is_cross, exe_wrap, is_64):
+        VisualStudioCPPCompiler.__init__(self, exelist, version, is_cross, exe_wrap, is_64)
+        self.id = 'clang-cl'
 
 class ArmCPPCompiler(ArmCompiler, CPPCompiler):
     def __init__(self, exelist, version, compiler_type, is_cross, exe_wrap=None, **kwargs):
diff --git a/mesonbuild/compilers/d.py b/mesonbuild/compilers/d.py
index 099d907..0a59e7f 100644
--- a/mesonbuild/compilers/d.py
+++ b/mesonbuild/compilers/d.py
@@ -274,6 +274,8 @@ class DCompiler(Compiler):
         return ['-Wl,-rpath,{}'.format(paths)]
 
     def _get_compiler_check_args(self, env, extra_args, dependencies, mode='compile'):
+        if callable(extra_args):
+            extra_args = extra_args(mode)
         if extra_args is None:
             extra_args = []
         elif isinstance(extra_args, str):
diff --git a/mesonbuild/dependencies/boost.py b/mesonbuild/dependencies/boost.py
index 17f9240..6a8050d 100644
--- a/mesonbuild/dependencies/boost.py
+++ b/mesonbuild/dependencies/boost.py
@@ -288,7 +288,7 @@ class BoostDependency(ExternalDependency):
         tag = None
         compiler = self.env.detect_cpp_compiler(self.want_cross)
         if mesonlib.for_windows(self.want_cross, self.env):
-            if compiler.get_id() == 'msvc':
+            if compiler.get_id() in ['msvc', 'clang-cl']:
                 comp_ts_version = compiler.get_toolset_version()
                 compiler_ts = comp_ts_version.split('.')
                 # FIXME - what about other compilers?
@@ -320,7 +320,7 @@ class BoostDependency(ExternalDependency):
 
     def arch_tag(self):
         # currently only applies to windows msvc installed binaries
-        if self.env.detect_cpp_compiler(self.want_cross).get_id() != 'msvc':
+        if self.env.detect_cpp_compiler(self.want_cross).get_id() not in ['msvc', 'clang-cl']:
             return ''
         # pre-compiled binaries only added arch tag for versions > 1.64
         if float(self.version) < 1.65:
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index 8c6c60e..dfed376 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -39,6 +39,8 @@ from .compilers import (
     ClangCPPCompiler,
     ClangObjCCompiler,
     ClangObjCPPCompiler,
+    ClangClCCompiler,
+    ClangClCPPCompiler,
     G95FortranCompiler,
     GnuCCompiler,
     GnuCPPCompiler,
@@ -190,6 +192,8 @@ def detect_windows_arch(compilers):
                 platform = os.environ.get('Platform', 'x86').lower()
             if platform == 'x86':
                 return platform
+        if compiler.id == 'clang-cl' and not compiler.is_64:
+            return 'x86'
         if compiler.id == 'gcc' and compiler.has_builtin_define('__i386__'):
             return 'x86'
     return os_arch
@@ -344,8 +348,8 @@ class Environment:
 
         # List of potential compilers.
         if mesonlib.is_windows():
-            self.default_c = ['cl', 'cc', 'gcc', 'clang']
-            self.default_cpp = ['cl', 'c++', 'g++', 'clang++']
+            self.default_c = ['cl', 'cc', 'gcc', 'clang', 'clang-cl']
+            self.default_cpp = ['cl', 'c++', 'g++', 'clang++', 'clang-cl']
         else:
             self.default_c = ['cc', 'gcc', 'clang']
             self.default_cpp = ['c++', 'g++', 'clang++']
@@ -359,6 +363,7 @@ class Environment:
         self.default_rust = ['rustc']
         self.default_static_linker = ['ar']
         self.vs_static_linker = ['lib']
+        self.clang_cl_static_linker = ['llvm-lib']
         self.gcc_static_linker = ['gcc-ar']
         self.clang_static_linker = ['llvm-ar']
 
@@ -537,7 +542,7 @@ This is probably wrong, it should always point to the native compiler.''' % evar
         for compiler in compilers:
             if isinstance(compiler, str):
                 compiler = [compiler]
-            if 'cl' in compiler or 'cl.exe' in compiler:
+            if not set(['cl', 'cl.exe', 'clang-cl', 'clang-cl.exe']).isdisjoint(compiler):
                 # Watcom C provides it's own cl.exe clone that mimics an older
                 # version of Microsoft's compiler. Since Watcom's cl.exe is
                 # just a wrapper, we skip using it if we detect its presence
@@ -606,6 +611,18 @@ This is probably wrong, it should always point to the native compiler.''' % evar
                 compiler_type = CompilerType.ARM_WIN
                 cls = ArmclangCCompiler if lang == 'c' else ArmclangCPPCompiler
                 return cls(ccache + compiler, version, compiler_type, is_cross, exe_wrap, full_version=full_version)
+            if 'CL.EXE COMPATIBILITY' in out:
+                # if this is clang-cl masquerading as cl, detect it as cl, not
+                # clang
+                arg = '--version'
+                try:
+                    p, out, err = Popen_safe(compiler + [arg])
+                except OSError as e:
+                    popen_exceptions[' '.join(compiler + [arg])] = e
+                version = search_version(out)
+                is_64 = 'Target: x86_64' in out
+                cls = ClangClCCompiler if lang == 'c' else ClangClCPPCompiler
+                return cls(compiler, version, is_cross, exe_wrap, is_64)
             if 'clang' in out:
                 if 'Apple' in out or mesonlib.for_darwin(want_cross, self):
                     compiler_type = CompilerType.CLANG_OSX
@@ -903,7 +920,7 @@ This is probably wrong, it should always point to the native compiler.''' % evar
             if evar in os.environ:
                 linkers = [shlex.split(os.environ[evar])]
             elif isinstance(compiler, compilers.VisualStudioCCompiler):
-                linkers = [self.vs_static_linker]
+                linkers = [self.vs_static_linker, self.clang_cl_static_linker]
             elif isinstance(compiler, compilers.GnuCompiler):
                 # Use gcc-ar if available; needed for LTO
                 linkers = [self.gcc_static_linker, self.default_static_linker]
@@ -913,14 +930,14 @@ This is probably wrong, it should always point to the native compiler.''' % evar
             elif isinstance(compiler, compilers.DCompiler):
                 # Prefer static linkers over linkers used by D compilers
                 if mesonlib.is_windows():
-                    linkers = [self.vs_static_linker, compiler.get_linker_exelist()]
+                    linkers = [self.vs_static_linker, self.clang_cl_static_linker, compiler.get_linker_exelist()]
                 else:
                     linkers = [self.default_static_linker, compiler.get_linker_exelist()]
             else:
                 linkers = [self.default_static_linker]
         popen_exceptions = {}
         for linker in linkers:
-            if 'lib' in linker or 'lib.exe' in linker:
+            if not set(['lib', 'lib.exe', 'llvm-lib', 'llvm-lib.exe']).isdisjoint(linker):
                 arg = '/?'
             else:
                 arg = '--version'
@@ -929,7 +946,7 @@ This is probably wrong, it should always point to the native compiler.''' % evar
             except OSError as e:
                 popen_exceptions[' '.join(linker + [arg])] = e
                 continue
-            if '/OUT:' in out or '/OUT:' in err:
+            if '/OUT:' in out.upper() or '/OUT:' in err.upper():
                 return VisualStudioLinker(linker)
             if p.returncode == 0 and ('armar' in linker or 'armar.exe' in linker):
                 return ArmarLinker(linker)
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index c2cfe5c..86b761e 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -38,6 +38,7 @@ import subprocess
 from collections import namedtuple
 from pathlib import PurePath
 import traceback
+import functools
 
 import importlib
 
@@ -965,7 +966,7 @@ class CompilerHolder(InterpreterObject):
     def cmd_array_method(self, args, kwargs):
         return self.compiler.exelist
 
-    def determine_args(self, kwargs):
+    def determine_args(self, kwargs, mode='link'):
         nobuiltins = kwargs.get('no_builtin_args', False)
         if not isinstance(nobuiltins, bool):
             raise InterpreterException('Type of no_builtin_args not a boolean.')
@@ -981,7 +982,8 @@ class CompilerHolder(InterpreterObject):
         if not nobuiltins:
             opts = self.environment.coredata.compiler_options
             args += self.compiler.get_option_compile_args(opts)
-            args += self.compiler.get_option_link_args(opts)
+            if mode == 'link':
+                args += self.compiler.get_option_link_args(opts)
         args += mesonlib.stringlistify(kwargs.get('args', []))
         return args
 
@@ -1039,7 +1041,7 @@ class CompilerHolder(InterpreterObject):
         testname = kwargs.get('name', '')
         if not isinstance(testname, str):
             raise InterpreterException('Testname argument must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs, endl=None)
         result = self.compiler.run(code, self.environment, extra_args, deps)
         if len(testname) > 0:
@@ -1094,7 +1096,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of has_member must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         had = self.compiler.has_members(typename, [membername], prefix,
                                         self.environment, extra_args, deps)
@@ -1122,7 +1124,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of has_members must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         had = self.compiler.has_members(typename, membernames, prefix,
                                         self.environment, extra_args, deps)
@@ -1175,7 +1177,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of has_type must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         had = self.compiler.has_type(typename, prefix, self.environment, extra_args, deps)
         if had:
@@ -1213,7 +1215,7 @@ class CompilerHolder(InterpreterObject):
             raise InterpreterException('High argument of compute_int must be an int.')
         if guess is not None and not isinstance(guess, int):
             raise InterpreterException('Guess argument of compute_int must be an int.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         res = self.compiler.compute_int(expression, low, high, guess, prefix, self.environment, extra_args, deps)
         mlog.log('Computing int of', mlog.bold(expression, True), msg, res)
@@ -1234,7 +1236,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of sizeof must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         esize = self.compiler.sizeof(element, prefix, self.environment, extra_args, deps)
         mlog.log('Checking for size of', mlog.bold(element, True), msg, esize)
@@ -1256,7 +1258,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of get_define() must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         value = self.compiler.get_define(element, prefix, self.environment, extra_args, deps)
         mlog.log('Fetching value of define', mlog.bold(element, True), msg, value)
@@ -1281,7 +1283,7 @@ class CompilerHolder(InterpreterObject):
         testname = kwargs.get('name', '')
         if not isinstance(testname, str):
             raise InterpreterException('Testname argument must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs, endl=None)
         result = self.compiler.compiles(code, self.environment, extra_args, deps)
         if len(testname) > 0:
@@ -1311,7 +1313,7 @@ class CompilerHolder(InterpreterObject):
         testname = kwargs.get('name', '')
         if not isinstance(testname, str):
             raise InterpreterException('Testname argument must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs, endl=None)
         result = self.compiler.links(code, self.environment, extra_args, deps)
         if len(testname) > 0:
@@ -1338,7 +1340,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of has_header must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         haz = self.compiler.check_header(hname, prefix, self.environment, extra_args, deps)
         if haz:
@@ -1363,7 +1365,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of has_header must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         haz = self.compiler.has_header(hname, prefix, self.environment, extra_args, deps)
         if haz:
@@ -1389,7 +1391,7 @@ class CompilerHolder(InterpreterObject):
         prefix = kwargs.get('prefix', '')
         if not isinstance(prefix, str):
             raise InterpreterException('Prefix argument of has_header_symbol must be a string.')
-        extra_args = self.determine_args(kwargs)
+        extra_args = functools.partial(self.determine_args, kwargs)
         deps, msg = self.determine_dependencies(kwargs)
         haz = self.compiler.has_header_symbol(hname, symbol, prefix, self.environment, extra_args, deps)
         if haz:
diff --git a/mesonbuild/modules/windows.py b/mesonbuild/modules/windows.py
index f0d5113..4d0f244 100644
--- a/mesonbuild/modules/windows.py
+++ b/mesonbuild/modules/windows.py
@@ -60,7 +60,7 @@ class WindowsModule(ExtensionModule):
 
         if not rescomp or not rescomp.found():
             comp = self.detect_compiler(state.compilers)
-            if comp.id == 'msvc':
+            if comp.id == 'msvc' or comp.id == 'clang-cl':
                 rescomp = ExternalProgram('rc', silent=True)
             else:
                 rescomp = ExternalProgram('windres', silent=True)
diff --git a/run_project_tests.py b/run_project_tests.py
index 2445dd4..c73567e 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -132,17 +132,17 @@ def platform_fix_name(fname, compiler, env):
 
     if fname.startswith('?msvc:'):
         fname = fname[6:]
-        if compiler != 'cl':
+        if compiler != 'msvc':
             return None
 
     if fname.startswith('?gcc:'):
         fname = fname[5:]
-        if compiler == 'cl':
+        if compiler == 'msvc':
             return None
 
     if fname.startswith('?cygwin:'):
         fname = fname[8:]
-        if compiler == 'cl' or not mesonlib.for_cygwin(env.is_cross_build(), env):
+        if compiler == 'msvc' or not mesonlib.for_cygwin(env.is_cross_build(), env):
             return None
 
     return fname
@@ -687,14 +687,18 @@ def check_meson_commands_work():
 
 def detect_system_compiler():
     global system_compiler
-    if shutil.which('cl'):
-        system_compiler = 'cl'
-    elif shutil.which('cc'):
-        system_compiler = 'cc'
-    elif shutil.which('gcc'):
-        system_compiler = 'gcc'
-    else:
-        raise RuntimeError("Could not find C compiler.")
+
+    with AutoDeletedDir(tempfile.mkdtemp(prefix='b ', dir='.')) as build_dir:
+        env = environment.Environment(None, build_dir, get_fake_options('/'))
+        try:
+            comp = env.detect_c_compiler(env.is_cross_build())
+        except:
+            raise RuntimeError("Could not find C compiler.")
+        system_compiler = comp.get_id()
+
+    # canonicalize for platform_fix_name()
+    if system_compiler == 'clang-cl':
+        system_compiler = 'msvc'
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description="Run the test suite of Meson.")
diff --git a/run_unittests.py b/run_unittests.py
index ee80a87..8aa0425 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -601,7 +601,7 @@ class InternalTests(unittest.TestCase):
         elif is_cygwin():
             self._test_all_naming(cc, env, patterns, 'cygwin')
         elif is_windows():
-            if cc.get_id() == 'msvc':
+            if cc.get_argument_syntax() == 'msvc':
                 self._test_all_naming(cc, env, patterns, 'windows-msvc')
             else:
                 self._test_all_naming(cc, env, patterns, 'windows-mingw')
@@ -624,10 +624,6 @@ class InternalTests(unittest.TestCase):
             with PatchModule(mesonbuild.compilers.c.for_windows,
                              'mesonbuild.compilers.c.for_windows', true):
                 self._test_all_naming(cc, env, patterns, 'windows-mingw')
-            cc.id = 'msvc'
-            with PatchModule(mesonbuild.compilers.c.for_windows,
-                             'mesonbuild.compilers.c.for_windows', true):
-                self._test_all_naming(cc, env, patterns, 'windows-msvc')
 
     def test_pkgconfig_parse_libs(self):
         '''
@@ -679,7 +675,7 @@ class InternalTests(unittest.TestCase):
             bar_dep = PkgConfigDependency('bar', env, kwargs)
             self.assertEqual(bar_dep.get_link_args(), [(p2 / 'libbar.a').as_posix()])
             internal_dep = PkgConfigDependency('internal', env, kwargs)
-            if compiler.get_id() == 'msvc':
+            if compiler.get_argument_syntax() == 'msvc':
                 self.assertEqual(internal_dep.get_link_args(), [])
             else:
                 link_args = internal_dep.get_link_args()
@@ -1602,6 +1598,7 @@ class AllPlatformTests(BasePlatformTests):
         clang = mesonbuild.compilers.ClangCompiler
         intel = mesonbuild.compilers.IntelCompiler
         msvc = mesonbuild.compilers.VisualStudioCCompiler
+        clangcl = mesonbuild.compilers.ClangClCCompiler
         ar = mesonbuild.linkers.ArLinker
         lib = mesonbuild.linkers.VisualStudioLinker
         langs = [('c', 'CC'), ('cpp', 'CXX')]
@@ -1623,6 +1620,9 @@ class AllPlatformTests(BasePlatformTests):
                 if ebase.startswith('g') or ebase.endswith(('-gcc', '-g++')):
                     self.assertIsInstance(ecc, gnu)
                     self.assertIsInstance(elinker, ar)
+                elif 'clang-cl' in ebase:
+                    self.assertIsInstance(ecc, clangcl)
+                    self.assertIsInstance(elinker, lib)
                 elif 'clang' in ebase:
                     self.assertIsInstance(ecc, clang)
                     self.assertIsInstance(elinker, ar)
@@ -1696,6 +1696,8 @@ class AllPlatformTests(BasePlatformTests):
                 wrapperlinker_s += shlex.quote(w) + ' '
             os.environ['AR'] = wrapperlinker_s
             wlinker = env.detect_static_linker(wcc)
+            # Pop it so we don't use it for the next detection
+            evalue = os.environ.pop('AR')
             # Must be the same type since it's a wrapper around the same exelist
             self.assertIs(type(cc), type(wcc))
             self.assertIs(type(linker), type(wlinker))
@@ -1994,7 +1996,7 @@ int main(int argc, char **argv) {
 
     def pbcompile(self, compiler, source, objectfile, extra_args=[]):
         cmd = compiler.get_exelist()
-        if compiler.id == 'msvc':
+        if compiler.get_argument_syntax() == 'msvc':
             cmd += ['/nologo', '/Fo' + objectfile, '/c', source] + extra_args
         else:
             cmd += ['-c', source, '-o', objectfile] + extra_args
@@ -2016,7 +2018,7 @@ int main(int argc, char **argv) {
     def build_static_lib(self, compiler, linker, source, objectfile, outfile, extra_args=None):
         if extra_args is None:
             extra_args = []
-        if compiler.id == 'msvc':
+        if compiler.get_argument_syntax() == 'msvc':
             link_cmd = ['lib', '/NOLOGO', '/OUT:' + outfile, objectfile]
         else:
             link_cmd = ['ar', 'csr', outfile, objectfile]
@@ -2049,9 +2051,10 @@ int main(int argc, char **argv) {
     def build_shared_lib(self, compiler, source, objectfile, outfile, impfile, extra_args=None):
         if extra_args is None:
             extra_args = []
-        if compiler.id == 'msvc':
-            link_cmd = ['link', '/NOLOGO', '/DLL', '/DEBUG',
-                        '/IMPLIB:' + impfile, '/OUT:' + outfile, objectfile]
+        if compiler.get_argument_syntax() == 'msvc':
+            link_cmd = compiler.get_linker_exelist() + [
+                '/NOLOGO', '/DLL', '/DEBUG', '/IMPLIB:' + impfile,
+                '/OUT:' + outfile, objectfile]
         else:
             extra_args += ['-fPIC']
             link_cmd = compiler.get_exelist() + ['-shared', '-o', outfile, objectfile]
@@ -2069,7 +2072,7 @@ int main(int argc, char **argv) {
         source = os.path.join(tdir, 'alexandria.c')
         objectfile = os.path.join(tdir, 'alexandria.' + object_suffix)
         impfile = os.path.join(tdir, 'alexandria.lib')
-        if cc.id == 'msvc':
+        if cc.get_argument_syntax() == 'msvc':
             shlibfile = os.path.join(tdir, 'alexandria.' + shared_suffix)
         elif is_cygwin():
             shlibfile = os.path.join(tdir, 'cygalexandria.' + shared_suffix)
@@ -2107,7 +2110,7 @@ int main(int argc, char **argv) {
         objectfile = os.path.join(testdir, 'foo.' + objext)
         stlibfile = os.path.join(testdir, 'libfoo.a')
         impfile = os.path.join(testdir, 'foo.lib')
-        if cc.id == 'msvc':
+        if cc.get_argument_syntax() == 'msvc':
             shlibfile = os.path.join(testdir, 'foo.' + shext)
         elif is_cygwin():
             shlibfile = os.path.join(testdir, 'cygfoo.' + shext)
@@ -2449,7 +2452,7 @@ recommended as it is not supported on some platforms''')
         testdirlib = os.path.join(testdirbase, 'lib')
         extra_args = None
         env = get_fake_env(testdirlib, self.builddir, self.prefix)
-        if env.detect_c_compiler(False).get_id() != 'msvc':
+        if env.detect_c_compiler(False).get_id() not in ['msvc', 'clang-cl']:
             # static libraries are not linkable with -l with msvc because meson installs them
             # as .a files which unix_args_to_native will not know as it expects libraries to use
             # .lib as extension. For a DLL the import library is installed as .lib. Thus for msvc
@@ -3058,7 +3061,7 @@ class WindowsTests(BasePlatformTests):
         testdir = os.path.join(self.platform_test_dir, '1 basic')
         env = get_fake_env(testdir, self.builddir, self.prefix)
         cc = env.detect_c_compiler(False)
-        if cc.id != 'msvc':
+        if cc.get_argument_syntax() != 'msvc':
             raise unittest.SkipTest('Not using MSVC')
         # To force people to update this test, and also test
         self.assertEqual(set(cc.ignore_libs), {'c', 'm', 'pthread', 'dl', 'rt'})
@@ -3070,7 +3073,7 @@ class WindowsTests(BasePlatformTests):
 
         # resource compiler depfile generation is not yet implemented for msvc
         env = get_fake_env(testdir, self.builddir, self.prefix)
-        depfile_works = env.detect_c_compiler(False).get_id() != 'msvc'
+        depfile_works = env.detect_c_compiler(False).get_id() not in ['msvc', 'clang-cl']
 
         self.init(testdir)
         self.build()
@@ -3097,9 +3100,14 @@ class WindowsTests(BasePlatformTests):
             self.utime(os.path.join(testdir, 'res', 'resource.h'))
             self.assertRebuiltTarget('prog_1')
 
-    @unittest.skipIf(shutil.which('cl') is None, 'Test only applies to VS')
     def test_msvc_cpp17(self):
         testdir = os.path.join(self.unit_test_dir, '45 vscpp17')
+
+        env = get_fake_env(testdir, self.builddir, self.prefix)
+        cc = env.detect_c_compiler(False)
+        if cc.get_argument_syntax() != 'msvc':
+            raise unittest.SkipTest('Test only applies to MSVC-like compilers')
+
         try:
             self.init(testdir)
         except subprocess.CalledProcessError:
diff --git a/test cases/common/100 manygen/subdir/manygen.py b/test cases/common/100 manygen/subdir/manygen.py
index 7ffd435..0fbc2ec 100755
--- a/test cases/common/100 manygen/subdir/manygen.py
+++ b/test cases/common/100 manygen/subdir/manygen.py
@@ -6,38 +6,30 @@ from __future__ import print_function
 # file and a header file.
 
 import sys, os
-import shutil, subprocess
+import subprocess
 
 with open(sys.argv[1]) as f:
     funcname = f.readline().strip()
 outdir = sys.argv[2]
 buildtype_args = sys.argv[3]
+compiler_type = sys.argv[4]
+compiler = sys.argv[5:]
 
 if not os.path.isdir(outdir):
     print('Outdir does not exist.')
     sys.exit(1)
 
-# Emulate the environment.detect_c_compiler() logic
-compiler = os.environ.get('CC', None)
-if not compiler:
-    compiler = shutil.which('cl') or \
-        shutil.which('gcc') or \
-        shutil.which('clang') or \
-        shutil.which('cc')
-
-compbase = os.path.basename(compiler)
-if 'cl' in compbase and 'clang' not in compbase:
+if compiler_type == 'msvc':
     libsuffix = '.lib'
     is_vs = True
-    compiler = 'cl'
-    linker = 'lib'
+    if any(['clang-cl' in c for c in compiler]):
+        linker = 'llvm-lib'
+    else:
+        linker = 'lib'
 else:
     libsuffix = '.a'
     is_vs = False
     linker = 'ar'
-    if compiler is None:
-        print('No known compilers found.')
-        sys.exit(1)
 
 objsuffix = '.o'
 
@@ -70,9 +62,9 @@ with open(tmpc, 'w') as f:
 ''' % funcname)
 
 if is_vs:
-    subprocess.check_call([compiler, '/nologo', '/c', buildtype_args, '/Fo' + outo, tmpc])
+    subprocess.check_call(compiler + ['/nologo', '/c', buildtype_args, '/Fo' + outo, tmpc])
 else:
-    subprocess.check_call([compiler, '-c', '-o', outo, tmpc])
+    subprocess.check_call(compiler + ['-c', '-o', outo, tmpc])
 
 with open(tmpc, 'w') as f:
     f.write('''int %s_in_lib() {
@@ -81,10 +73,10 @@ with open(tmpc, 'w') as f:
 ''' % funcname)
 
 if is_vs:
-    subprocess.check_call([compiler, '/nologo', '/c', '/Fo' + tmpo, tmpc])
+    subprocess.check_call(compiler + ['/nologo', '/c', '/Fo' + tmpo, tmpc])
     subprocess.check_call([linker, '/NOLOGO', '/OUT:' + outa, tmpo])
 else:
-    subprocess.check_call([compiler, '-c', '-o', tmpo, tmpc])
+    subprocess.check_call(compiler + ['-c', '-o', tmpo, tmpc])
     subprocess.check_call([linker, 'csr', outa, tmpo])
 
 os.unlink(tmpo)
diff --git a/test cases/common/100 manygen/subdir/meson.build b/test cases/common/100 manygen/subdir/meson.build
index 73b4ff7..56f60e6 100644
--- a/test cases/common/100 manygen/subdir/meson.build
+++ b/test cases/common/100 manygen/subdir/meson.build
@@ -3,7 +3,8 @@ py3_bin = import('python3').find_python()
 
 buildtype = get_option('buildtype')
 buildtype_args = '-Dfooxxx' # a useless compiler argument
-if meson.get_compiler('c').get_id() == 'msvc'
+cc = meson.get_compiler('c')
+if cc.get_argument_syntax() == 'msvc'
   # We need our manually generated code to use the same CRT as the executable.
   # Taken from compilers.py since build files do not have access to this.
   if buildtype == 'debug'
@@ -21,5 +22,5 @@ endif
 generated = custom_target('manygen',
   output : outfiles,
   input : ['funcinfo.def'],
-  command : [py3_bin, gen[0], '@INPUT@', '@OUTDIR@', buildtype_args],
+  command : [py3_bin, gen[0], '@INPUT@', '@OUTDIR@', buildtype_args, cc.get_argument_syntax(), cc.cmd_array()],
 )
diff --git a/test cases/common/112 spaces backslash/meson.build b/test cases/common/112 spaces backslash/meson.build
index bf614e8..d590494 100644
--- a/test cases/common/112 spaces backslash/meson.build
+++ b/test cases/common/112 spaces backslash/meson.build
@@ -7,7 +7,7 @@ project('comparer', 'c')
 include_dir = meson.current_source_dir() + '/include'
 default_c_args = ['-I' + include_dir]
 
-if meson.get_compiler('c').get_id() == 'msvc'
+if meson.get_compiler('c').get_argument_syntax() == 'msvc'
   default_c_args += ['/Faasm output\\']
   # Hack to create the 'asm output' directory in the builddir
   subdir('asm output')
diff --git a/test cases/common/123 llvm ir and assembly/meson.build b/test cases/common/123 llvm ir and assembly/meson.build
index 51321fb..a67c6c6 100644
--- a/test cases/common/123 llvm ir and assembly/meson.build
+++ b/test cases/common/123 llvm ir and assembly/meson.build
@@ -28,15 +28,18 @@ foreach lang : ['c', 'cpp']
   # MSVC cannot directly compile assembly files, so we pass it through the
   # cl.exe pre-processor first and then assemble it with the ml.exe assembler.
   # Then we can link it into the executable.
-  if cc_id == 'msvc'
-    cl = find_program('cl')
+  if cc.get_argument_syntax() == 'msvc'
+    cl = cc.cmd_array()
     if cpu == 'x86'
-      ml = find_program('ml')
+      ml = find_program('ml', required: false)
     elif cpu == 'x86_64'
-      ml = find_program('ml64')
+      ml = find_program('ml64', required: false)
     else
       error('Unsupported cpu family: "' + cpu + '"')
     endif
+    if not ml.found()
+      error('MESON_SKIP_TEST: ML (masm) not found')
+    endif
     # Preprocess file (ml doesn't support pre-processing)
     preproc_name = lang + square_base + '.i'
     square_preproc = custom_target(lang + square_impl + 'preproc',
diff --git a/test cases/common/124 cpp and asm/meson.build b/test cases/common/124 cpp and asm/meson.build
index 9160775..f097084 100644
--- a/test cases/common/124 cpp and asm/meson.build
+++ b/test cases/common/124 cpp and asm/meson.build
@@ -15,7 +15,7 @@ endif
 
 sources = ['trivial.cc']
 # If the compiler cannot compile assembly, don't use it
-if meson.get_compiler('cpp').get_id() != 'msvc'
+if not ['msvc', 'clang-cl'].contains(meson.get_compiler('cpp').get_id())
   sources += ['retval-' + cpu + '.S']
   cpp_args = ['-DUSE_ASM']
   message('Using ASM')
diff --git a/test cases/common/127 no buildincdir/meson.build b/test cases/common/127 no buildincdir/meson.build
index ac69e8e..53f1a7f 100644
--- a/test cases/common/127 no buildincdir/meson.build
+++ b/test cases/common/127 no buildincdir/meson.build
@@ -1,5 +1,5 @@
 project('nobuilddir', 'c',
-  default_options : 'werror=true')
+  default_options : ['werror=true', 'buildtype=plain'])
 
 cc = meson.get_compiler('c')
 
diff --git a/test cases/common/13 pch/mixed/meson.build b/test cases/common/13 pch/mixed/meson.build
index 7f6033d..f0c3eca 100644
--- a/test cases/common/13 pch/mixed/meson.build
+++ b/test cases/common/13 pch/mixed/meson.build
@@ -5,8 +5,9 @@ exe = executable(
   cpp_pch : ['pch/main_pch.cc', 'pch/main.h'],
 )
 
+# test pch when only a header is given (not supported by msvc)
 cc = meson.get_compiler('c')
-if cc.get_id() != 'msvc'
+if not ['msvc', 'clang-cl'].contains(cc.get_id())
   exe2 = executable(
     'prog2',
     files('main.cc', 'func.c'),
diff --git a/test cases/common/132 generated assembly/meson.build b/test cases/common/132 generated assembly/meson.build
index 6a8744b..5fb7429 100644
--- a/test cases/common/132 generated assembly/meson.build
+++ b/test cases/common/132 generated assembly/meson.build
@@ -2,8 +2,8 @@ project('generated assembly', 'c')
 
 cc = meson.get_compiler('c')
 
-if cc.get_id() == 'msvc'
-  error('MESON_SKIP_TEST: assembly files cannot be compiled directly by MSVC')
+if ['msvc', 'clang-cl'].contains(cc.get_id())
+  error('MESON_SKIP_TEST: assembly files cannot be compiled directly by the compiler')
 endif
 
 cpu = host_machine.cpu_family()
diff --git a/test cases/common/138 c cpp and asm/meson.build b/test cases/common/138 c cpp and asm/meson.build
index 2c3610e..ca820e2 100644
--- a/test cases/common/138 c cpp and asm/meson.build
+++ b/test cases/common/138 c cpp and asm/meson.build
@@ -9,7 +9,7 @@ if not supported_cpus.contains(cpu)
   error('MESON_SKIP_TEST unsupported cpu:' + cpu)
 endif
 
-if meson.get_compiler('c').get_id() == 'msvc'
+if meson.get_compiler('c').get_argument_syntax() == 'msvc'
   error('MESON_SKIP_TEST MSVC can\'t compile assembly')
 endif
 
diff --git a/test cases/common/143 C and CPP link/meson.build b/test cases/common/143 C and CPP link/meson.build
index 55c1b87..af5c54a 100644
--- a/test cases/common/143 C and CPP link/meson.build
+++ b/test cases/common/143 C and CPP link/meson.build
@@ -25,9 +25,10 @@ libc = static_library('cfoo', ['foo.c', 'foo.h'])
 # ourselves at configure time and then 'find' it with cxx.find_library().
 cxx = meson.get_compiler('cpp')
 
-if cxx.get_id() == 'msvc'
+if cxx.get_argument_syntax() == 'msvc'
+  static_linker = find_program('lib', 'llvm-lib')
   compile_cmd = ['/c', '@INPUT@', '/Fo@OUTPUT@']
-  stlib_cmd = ['lib', '/OUT:@OUTPUT@', '@INPUT@']
+  stlib_cmd = [static_linker, '/OUT:@OUTPUT@', '@INPUT@']
 else
   compile_cmd = ['-c', '-fPIC', '@INPUT@', '-o', '@OUTPUT@']
   stlib_cmd = ['ar', 'csr', '@OUTPUT@', '@INPUT@']
diff --git a/test cases/common/186 has link arg/meson.build b/test cases/common/186 has link arg/meson.build
index e166101..10f2218 100644
--- a/test cases/common/186 has link arg/meson.build
+++ b/test cases/common/186 has link arg/meson.build
@@ -3,7 +3,7 @@ project('has link arg', 'c', 'cpp')
 cc = meson.get_compiler('c')
 cpp = meson.get_compiler('cpp')
 
-if cc.get_id() == 'msvc'
+if cc.get_argument_syntax() == 'msvc'
   is_arg = '/OPT:REF'
   useless = '/DEBUG'
   isnt_arg = '/iambroken'
diff --git a/test cases/common/190 openmp/meson.build b/test cases/common/190 openmp/meson.build
index eb270ab..018bf24 100644
--- a/test cases/common/190 openmp/meson.build
+++ b/test cases/common/190 openmp/meson.build
@@ -10,6 +10,9 @@ endif
 if cc.get_id() == 'msvc' and cc.version().version_compare('<17')
   error('MESON_SKIP_TEST msvc is too old to support OpenMP.')
 endif
+if cc.get_id() == 'clang-cl'
+  error('MESON_SKIP_TEST clang-cl does not support OpenMP.')
+endif
 if host_machine.system() == 'darwin'
   error('MESON_SKIP_TEST macOS does not support OpenMP.')
 endif
diff --git a/test cases/common/204 function attributes/meson.build b/test cases/common/204 function attributes/meson.build
index e46533f..c906b49 100644
--- a/test cases/common/204 function attributes/meson.build
+++ b/test cases/common/204 function attributes/meson.build
@@ -19,7 +19,7 @@ project('gcc func attributes', ['c', 'cpp'])
 c = meson.get_compiler('c')
 cpp = meson.get_compiler('cpp')
 
-expected_result = c.get_id() != 'msvc'
+expected_result = not ['msvc', 'clang-cl'].contains(c.get_id())
 
 # Q: Why is ifunc not in this list or any of the below lists?
 # A: It's too damn hard to figure out if you actually support it, since it
@@ -57,8 +57,6 @@ if c.get_id() != 'intel'
   attributes += 'weakref'
 endif
 
-expected_result = c.get_id() != 'msvc'
-
 # These are unsupported on darwin with apple clang 9.1.0
 if host_machine.system() != 'darwin'
   attributes += 'alias'
@@ -97,7 +95,7 @@ foreach a : ['dllexport', 'dllimport']
 endforeach
 
 message('checking get_supported_function_attributes')
-if c.get_id() != 'msvc'
+if not ['msvc', 'clang-cl'].contains(c.get_id())
   multi_expected = attributes
 else
   multi_expected = []
diff --git a/test cases/common/206 argument syntax/meson.build b/test cases/common/206 argument syntax/meson.build
index c884f90..216da45 100644
--- a/test cases/common/206 argument syntax/meson.build
+++ b/test cases/common/206 argument syntax/meson.build
@@ -7,7 +7,7 @@ cc = meson.get_compiler('c')
 
 if ['gcc', 'lcc', 'clang'].contains(cc.get_id())
   expected = 'gcc'
-elif cc.get_id() == 'msvc'
+elif ['msvc', 'clang-cl'].contains(cc.get_id())
   expected = 'msvc'
 elif cc.get_id() == 'intel'
   if host_machine.system() == 'windows'
diff --git a/test cases/common/91 default options/meson.build b/test cases/common/91 default options/meson.build
index 9f45df0..c4c72ef 100644
--- a/test cases/common/91 default options/meson.build
+++ b/test cases/common/91 default options/meson.build
@@ -6,11 +6,9 @@ project('default options', 'cpp', 'c', default_options : [
   'warning_level=3',
   ])
 
-cpp_id = meson.get_compiler('cpp').get_id()
-
 assert(get_option('buildtype') == 'debugoptimized', 'Build type default value wrong.')
 
-if cpp_id == 'msvc'
+if meson.get_compiler('cpp').get_argument_syntax() == 'msvc'
   cpp_eh = get_option('cpp_eh')
   assert(cpp_eh == 'none', 'MSVC eh value is "' + cpp_eh + '" instead of "none"')
 else
@@ -33,4 +31,3 @@ assert(w_level == '3', 'warning level "' + w_level + '" instead of "3"')
 #   assert(not cc.compiles('int foobar;'), 'Default arg not used in test.')
 #   assert(cc.compiles('int foobar;', no_builtin_args : true), 'No_builtin did not disable builtins.')
 # endif
-
diff --git a/test cases/windows/16 gui app/meson.build b/test cases/windows/16 gui app/meson.build
index 2435218..224d708 100644
--- a/test cases/windows/16 gui app/meson.build
+++ b/test cases/windows/16 gui app/meson.build
@@ -17,6 +17,10 @@ console_prog = executable('console_prog', 'console_prog.c', gui_app: false)
 
 tester = find_program('gui_app_tester.py')
 
-tool = find_program('objdump', 'dumpbin')
-test('is_gui', tester, args: [tool.path(), gui_prog, '2'])
-test('not_gui', tester, args: [tool.path(), console_prog, '3'])
+tool = find_program('objdump', 'dumpbin', required: false)
+# TODO: when 'llvm-objdump -f' emits the subsystem type, we could use that also
+
+if tool.found()
+  test('is_gui', tester, args: [tool.path(), gui_prog, '2'])
+  test('not_gui', tester, args: [tool.path(), console_prog, '3'])
+endif