Get test-suite configuring on Windows with clang-cl

This patch gets the test suite "working" on Windows, although
none of the tests pass.

In order to reuse the existing configuration, which uses UNIX
style flags not accepted by clang-cl, this patch only works with clang++.
When clang-cl is specified the test harness secretly looks for
clang++ and then it configures it using the INCLUDE and LIB enviroment
variables.

This is very much a work in progress.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@291072 91177308-0d34-0410-b5e6-96231b3b80d8

test/libcxx/test/config.py

@@ -57,7 +57,9 @@ class Configuration(object):
     def __init__(self, lit_config, config):
         self.lit_config = lit_config
         self.config = config
+        self.is_windows = platform.system() == 'Windows'
         self.cxx = None
+        self.cxx_is_clang_cl = None
         self.cxx_stdlib_under_test = None
         self.project_obj_root = None
         self.libcxx_src_root = None
@@ -95,6 +97,13 @@ class Configuration(object):
         self.lit_config.fatal(
             "parameter '{}' should be true or false".format(name))
 
+    def make_static_lib_name(self, name):
+        """Return the full filename for the specified library name"""
+        if self.is_windows:
+            return name + '.lib'
+        else:
+            return 'lib' + name + '.a'
+
     def configure(self):
         self.configure_executor()
         self.configure_target_info()
@@ -171,20 +180,25 @@ class Configuration(object):
     def configure_cxx(self):
         # Gather various compiler parameters.
         cxx = self.get_lit_conf('cxx_under_test')
-
+        self.cxx_is_clang_cl = cxx is not None and \
+                               os.path.basename(cxx) == 'clang-cl.exe'
         # If no specific cxx_under_test was given, attempt to infer it as
         # clang++.
-        if cxx is None:
+        if cxx is None or self.cxx_is_clang_cl:
             clangxx = lit.util.which('clang++',
                                      self.config.environment['PATH'])
             if clangxx:
                 cxx = clangxx
                 self.lit_config.note(
                     "inferred cxx_under_test as: %r" % cxx)
+            elif self.cxx_is_clang_cl:
+                self.lit_config.fatal('Failed to find clang++ substitution for'
+                                      ' clang-cl')
         if not cxx:
             self.lit_config.fatal('must specify user parameter cxx_under_test '
                                   '(e.g., --param=cxx_under_test=clang++)')
-        self.cxx = CXXCompiler(cxx)
+        self.cxx = CXXCompiler(cxx) if not self.cxx_is_clang_cl else \
+                   self._configure_clang_cl(cxx)
         cxx_type = self.cxx.type
         if cxx_type is not None:
             assert self.cxx.version is not None
@@ -194,6 +208,25 @@ class Configuration(object):
             self.config.available_features.add('%s-%s.%s' % (
                 cxx_type, maj_v, min_v))
 
+    def _configure_clang_cl(self, clang_path):
+        assert self.cxx_is_clang_cl
+        # FIXME: don't hardcode the target
+        flags = ['-fms-compatibility-version=19.00',
+                 '--target=i686-unknown-windows']
+        compile_flags = []
+        link_flags = ['-fuse-ld=lld']
+        if 'INCLUDE' in os.environ:
+            compile_flags += ['-isystem %s' % p.strip()
+                              for p in os.environ['INCLUDE'].split(';')
+                              if p.strip()]
+        if 'LIB' in os.environ:
+            link_flags += ['-L%s' % p.strip()
+                           for p in os.environ['LIB'].split(';') if p.strip()]
+        return CXXCompiler(clang_path, flags=flags,
+                           compile_flags=compile_flags,
+                           link_flags=link_flags)
+
+
     def configure_src_root(self):
         self.libcxx_src_root = self.get_lit_conf(
             'libcxx_src_root', os.path.dirname(self.config.test_source_root))
@@ -400,7 +433,8 @@ class Configuration(object):
 
     def configure_compile_flags_header_includes(self):
         support_path = os.path.join(self.libcxx_src_root, 'test/support')
-        if self.cxx_stdlib_under_test != 'libstdc++':
+        if self.cxx_stdlib_under_test != 'libstdc++' and \
+           not self.is_windows:
             self.cxx.compile_flags += [
                 '-include', os.path.join(support_path, 'nasty_macros.hpp')]
         self.configure_config_site_header()
@@ -459,6 +493,8 @@ class Configuration(object):
         # Transform each macro name into the feature name used in the tests.
         # Ex. _LIBCPP_HAS_NO_THREADS -> libcpp-has-no-threads
         for m in feature_macros:
+            if m == '_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS':
+                continue
             if m == '_LIBCPP_ABI_VERSION':
                 self.config.available_features.add('libcpp-abi-version-v%s'
                     % feature_macros[m])
@@ -558,15 +594,16 @@ class Configuration(object):
         if not self.use_system_cxx_lib:
             if self.cxx_library_root:
                 self.cxx.link_flags += ['-L' + self.cxx_library_root]
-            if self.cxx_runtime_root:
+            if self.cxx_runtime_root and not self.is_windows:
                 self.cxx.link_flags += ['-Wl,-rpath,' + self.cxx_runtime_root]
 
     def configure_link_flags_abi_library_path(self):
         # Configure ABI library paths.
         self.abi_library_root = self.get_lit_conf('abi_library_path')
         if self.abi_library_root:
-            self.cxx.link_flags += ['-L' + self.abi_library_root,
+            self.cxx.link_flags += ['-L' + self.abi_library_root]
-                                    '-Wl,-rpath,' + self.abi_library_root]
+            if not self.is_windows:
+                self.cxx.link_flags += ['-Wl,-rpath,' + self.abi_library_root]
 
     def configure_link_flags_cxx_library(self):
         libcxx_experimental = self.get_lit_bool('enable_experimental', default=False)
@@ -579,7 +616,10 @@ class Configuration(object):
         else:
             cxx_library_root = self.get_lit_conf('cxx_library_root')
             if cxx_library_root:
-                abs_path = os.path.join(cxx_library_root, 'libc++.a')
+                libname = self.make_static_lib_name('c++')
+                abs_path = os.path.join(cxx_library_root, libname)
+                assert os.path.exists(abs_path) and \
+                       "static libc++ library does not exist"
                 self.cxx.link_flags += [abs_path]
             else:
                 self.cxx.link_flags += ['-lc++']
@@ -598,7 +638,8 @@ class Configuration(object):
                 else:
                     cxxabi_library_root = self.get_lit_conf('abi_library_path')
                     if cxxabi_library_root:
-                        abs_path = os.path.join(cxxabi_library_root, 'libc++abi.a')
+                        libname = self.make_static_lib_name('c++abi')
+                        abs_path = os.path.join(cxxabi_library_root, libname)
                         self.cxx.link_flags += [abs_path]
                     else:
                         self.cxx.link_flags += ['-lc++abi']