[libcxx] [test] Fix testing on windows with c++experimental enabled

The straightforward `AddLinkFlag('-lc++experimental')` approach doesn't
work on e.g. MSVC. For linking to libc++ itself, a more convoluted logic
is used (see configure_link_flags_cxx_library).

Differential Revision: https://reviews.llvm.org/D99177

diff --git a/libcxx/utils/libcxx/test/features.py b/libcxx/utils/libcxx/test/features.py
index e54cece..2fb7e00 100644 (file)
--- a/libcxx/utils/libcxx/test/features.py
+++ b/libcxx/utils/libcxx/test/features.py
@@ -14,6 +14,8 @@ import sys
 _isClang      = lambda cfg: '__clang__' in compilerMacros(cfg) and '__apple_build_version__' not in compilerMacros(cfg)
 _isAppleClang = lambda cfg: '__apple_build_version__' in compilerMacros(cfg)
 _isGCC        = lambda cfg: '__GNUC__' in compilerMacros(cfg) and '__clang__' not in compilerMacros(cfg)
+_isMSVC       = lambda cfg: '_MSC_VER' in compilerMacros(cfg)
+_msvcVersion  = lambda cfg: (int(compilerMacros(cfg)['_MSC_VER']) // 100, int(compilerMacros(cfg)['_MSC_VER']) % 100)
 
 DEFAULT_FEATURES = [
   Feature(name='fcoroutines-ts',
@@ -81,6 +83,10 @@ DEFAULT_FEATURES = [
   Feature(name=lambda cfg: 'gcc-{__GNUC__}'.format(**compilerMacros(cfg)),                                                         when=_isGCC),
   Feature(name=lambda cfg: 'gcc-{__GNUC__}.{__GNUC_MINOR__}'.format(**compilerMacros(cfg)),                                        when=_isGCC),
   Feature(name=lambda cfg: 'gcc-{__GNUC__}.{__GNUC_MINOR__}.{__GNUC_PATCHLEVEL__}'.format(**compilerMacros(cfg)),                  when=_isGCC),
+
+  Feature(name='msvc',                                                                                                             when=_isMSVC),
+  Feature(name=lambda cfg: 'msvc-{}'.format(*_msvcVersion(cfg)),                                                                   when=_isMSVC),
+  Feature(name=lambda cfg: 'msvc-{}.{}'.format(*_msvcVersion(cfg)),                                                                when=_isMSVC),
 ]
 
 # Deduce and add the test features that that are implied by the #defines in

diff --git a/libcxx/utils/libcxx/test/params.py b/libcxx/utils/libcxx/test/params.py
index 9d1d83a..ddf277d 100644 (file)
--- a/libcxx/utils/libcxx/test/params.py
+++ b/libcxx/utils/libcxx/test/params.py
@@ -7,6 +7,7 @@
 #===----------------------------------------------------------------------===##
 
 from libcxx.test.dsl import *
+from libcxx.test.features import _isMSVC
 
 _warningFlags = [
   '-Werror',
@@ -111,7 +112,12 @@ DEFAULT_PARAMETERS = [
             help="Whether to enable tests for experimental C++ libraries (typically Library Fundamentals TSes).",
             actions=lambda experimental: [] if not experimental else [
               AddFeature('c++experimental'),
-              PrependLinkFlag('-lc++experimental')
+              # When linking in MSVC mode via the Clang driver, a -l<foo>
+              # maps to <foo>.lib, so we need to use -llibc++experimental here
+              # to make it link against the static libc++experimental.lib.
+              # We can't check for the feature 'msvc' in available_features
+              # as those features are added after processing parameters.
+              PrependLinkFlag(lambda config: '-llibc++experimental' if _isMSVC(config) else '-lc++experimental')
             ]),
 
   Parameter(name='long_tests', choices=[True, False], type=bool, default=True,