[lldb] -stdlib=libc++ for linking with lldb lib also if LLVM_ENABLE_LIBCXX

[llunak]

Summary

Otherwise on Linux e.g. the api/command-return-object test uses libstdc++ for the test app and libc++ is used for the lldb library, and some objects such as std::shared_ptr are not binary compatible between the two libs, leading to "mysterious" crashes.

[teemperor]

Thanks for working on this! This looks good to me, but I wonder if doing this with a dedicated flag instead of an environment variable would be better. But I'll leave that to the others who have a better idea how the dotest flags should work.

Out of curiosity, will this also fix the TestPluginCommands.py ?

lldb/test/API/lit.site.cfg.py.in

24

Maybe move this below the config.llvm_use_sanitizer line, as this is currently in the middle of the python/dotest.py-related config flags.

[JDevlieghere]

In D86416#2232966, @teemperor wrote:

This looks good to me, but I wonder if doing this with a dedicated flag instead of an environment variable would be better. But I'll leave that to the others who have a better idea how the dotest flags should work.

Yeah, please make this a dedicated flag and store its value in the configuration. We've been slowly (but steadily) moving away from passing around things trough the environment.

[labath]

I actually think tests relying on this should be converted to c++ unit tests. The logic to compile and link against liblldb takes up a considerable chunk of our test buildsystem. Why recreate that logic, when cmake knows how to do that already? TestPluginCommands might be more involved, but converting api/command-return-object should be trivial using the api unit test framework we already have (unittests/API)...

[llunak]

Updated to not use environment variable.

[llunak]

In D86416#2232966, @teemperor wrote:

Out of curiosity, will this also fix the TestPluginCommands.py ?

Yes.

[llunak]

Ping.

[llunak]

Ping.

[JDevlieghere]

The change to use the configuration looks good, but I think Pavel raised a good point. Which tests are affected by this? How much work would it be to convert them as suggested?

[llunak]

In D86416#2286333, @JDevlieghere wrote:

Which tests are affected by this?

I don't know. There are 5 hits for 'buildDriver' and 8 for '%include_SB_APIs%' under tests/, so at least 13, but I don't know if that's all.

How much work would it be to convert them as suggested?

I don't know either. I don't plan on doing that, at least not now. My patch is a fix and it's done. The suggestion is an improvement. surely it can be done after the fix.

lldb/packages/Python/lldbsuite/test/configuration.py

 
 # The names of all tests. Used to assert we don't have two tests with the
 # same base name.
 all_tests = set()
 
 # LLDB library directory.
 lldb_libs_dir = None
 
+# Whether to force use of libc++ when using liblldb.
+libcxx_used = False
+
 # A plugin whose tests will be enabled, like intel-pt.
 enabled_plugins = []
 
 
 def shouldSkipBecauseOfCategories(test_categories):
     if use_categories:
         if len(test_categories) == 0 or len(
                 categories_list & set(test_categories)) == 0:

lldb/packages/Python/lldbsuite/test/dotest.py

if args.clang_module_cache_dir:
         configuration.clang_module_cache_dir = args.clang_module_cache_dir
     else:
         configuration.clang_module_cache_dir = os.path.join(
             configuration.test_build_dir, 'module-cache-clang')
 
     if args.lldb_libs_dir:
         configuration.lldb_libs_dir = args.lldb_libs_dir
 
+    if args.libcxx_used:
+        configuration.libcxx_used = args.libcxx_used
+
     if args.enabled_plugins:
         configuration.enabled_plugins = args.enabled_plugins
 
     # Gather all the dirs passed on the command line.
     if len(args.args) > 0:
         configuration.testdirs = [os.path.realpath(os.path.abspath(x)) for x in args.args]
 
     lldbtest_config.codesign_identity = args.codesign_identity

lldb/packages/Python/lldbsuite/test/dotest_args.py

group.add_argument(
         metavar='The clang module cache directory used by Clang',
         help='The clang module cache directory used in the Make files by Clang while building tests. Defaults to <test build directory>/module-cache-clang.')
     group.add_argument(
         '--lldb-libs-dir',
         dest='lldb_libs_dir',
         metavar='path',
         help='The path to LLDB library directory (containing liblldb)')
     group.add_argument(
+        '--libcxx-used',
+        dest='libcxx_used',
+        metavar='libc++ used',
+        help='Whether to force use of libc++ when using liblldb')
+    group.add_argument(
         '--enable-plugin',
         dest='enabled_plugins',
         action='append',
         type=str,
         metavar='A plugin whose tests will be enabled',
         help='A plugin whose tests will be enabled. The only currently supported plugin is intel-pt.')
 
     # Configuration options

lldb/packages/Python/lldbsuite/test/lldbtest.py

class Base(unittest2.TestCase):
     # ==================================================
 
     def getstdlibFlag(self):
         """ Returns the proper -stdlib flag, or empty if not required."""
         if self.platformIsDarwin() or self.getPlatform() == "freebsd" or self.getPlatform() == "openbsd":
             stdlibflag = "-stdlib=libc++"
         else:  # this includes NetBSD
             stdlibflag = ""
+        if configuration.libcxx_used:
+            stdlibflag = "-stdlib=libc++"
         return stdlibflag
 
     def getstdFlag(self):
         """ Returns the proper stdflag. """
         if "gcc" in self.getCompiler() and "4.6" in self.getCompilerVersion():
             stdflag = "-std=c++0x"
         else:
             stdflag = "-std=c++11"
def buildDriver(self, sources, exe_name):
                 (exe_name, sources))
 
         self.buildDefault(dictionary=d)
 
     def buildLibrary(self, sources, lib_name):
         """Platform specific way to build a default library. """
 
         stdflag = self.getstdFlag()
+        stdlibflag = self.getstdlibFlag()
 
         lib_dir = configuration.lldb_libs_dir
         if self.hasDarwinFramework():
             d = {'DYLIB_CXX_SOURCES': sources,
                  'DYLIB_NAME': lib_name,
-                 'CFLAGS_EXTRAS': "%s -stdlib=libc++" % stdflag,
+                 'CFLAGS_EXTRAS': "%s %s" % (stdflag, stdlibflag),
                  'FRAMEWORK_INCLUDES': "-F%s" % self.framework_dir,
                  'LD_EXTRAS': "%s -Wl,-rpath,%s -dynamiclib" % (self.dsym, self.framework_dir),
                  }
         elif self.getPlatform() == 'windows':
             d = {
                 'DYLIB_CXX_SOURCES': sources,
                 'DYLIB_NAME': lib_name,
-                'CFLAGS_EXTRAS': "%s -I%s " % (stdflag,
+                'CFLAGS_EXTRAS': "%s %s -I%s " % (stdflag,
+                                                  stdlibflag,
                                                   os.path.join(
                                                       os.environ["LLDB_SRC"],
                                                       "include")),
                 'LD_EXTRAS': "-shared -l%s\liblldb.lib" % self.os.environ["LLDB_IMPLIB_DIR"]}
         else:
             d = {
                 'DYLIB_CXX_SOURCES': sources,
                 'DYLIB_NAME': lib_name,
-                'CFLAGS_EXTRAS': "%s -I%s -fPIC" % (stdflag,
+                'CFLAGS_EXTRAS': "%s %s -I%s -fPIC" % (stdflag,
+                                                       stdlibflag,
                                                        os.path.join(
                                                            os.environ["LLDB_SRC"],
                                                            "include")),
                 'LD_EXTRAS': "-shared -L%s -llldb -Wl,-rpath,%s" % (lib_dir, lib_dir)}
         if self.TraceOn():
             print(
                 "Building LLDB Library (%s) from sources %s" %
                 (lib_name, sources))
 
         self.buildDefault(dictionary=d)
 

lldb/test/API/lit.cfg.py

if config.filecheck:
   dotest_cmd += ['--filecheck', config.filecheck]
 
 if config.yaml2obj:
   dotest_cmd += ['--yaml2obj', config.yaml2obj]
 
 if config.lldb_libs_dir:
   dotest_cmd += ['--lldb-libs-dir', config.lldb_libs_dir]
 
+if config.libcxx_used:
+  dotest_cmd += ['--libcxx-used']
+
 if 'lldb-repro-capture' in config.available_features or \
     'lldb-repro-replay' in config.available_features:
   dotest_cmd += ['--skip-category=lldb-vscode', '--skip-category=std-module']
 
 if config.enabled_plugins:
   for plugin in config.enabled_plugins:
     dotest_cmd += ['--enable-plugin', plugin]
 

lldb/test/API/lit.site.cfg.py.in

 @LIT_SITE_CFG_IN_HEADER@
 
 config.test_exec_root = "@LLDB_BINARY_DIR@"
 config.llvm_src_root = "@LLVM_SOURCE_DIR@"
 config.llvm_obj_root = "@LLVM_BINARY_DIR@"
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.llvm_libs_dir = "@LLVM_LIBS_DIR@"
 config.llvm_shlib_dir = "@SHLIBDIR@"
 config.llvm_build_mode = "@LLVM_BUILD_MODE@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.lldb_obj_root = "@LLDB_BINARY_DIR@"
 config.lldb_src_root = "@LLDB_SOURCE_DIR@"
 config.lldb_libs_dir = "@LLDB_LIBS_DIR@"
 config.cmake_cxx_compiler = "@CMAKE_CXX_COMPILER@"
+config.libcxx_used = @LLVM_LIBCXX_USED@
 config.host_os = "@HOST_OS@"
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.shared_libs = @LLVM_ENABLE_SHARED_LIBS@
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.target_triple = "@TARGET_TRIPLE@"
 config.lldb_build_directory = "@LLDB_TEST_BUILD_DIRECTORY@"
 config.lldb_reproducer_directory = os.path.join("@LLDB_TEST_BUILD_DIRECTORY@", "reproducers")
 config.python_executable = "@Python3_EXECUTABLE@"
 config.dotest_path = "@LLDB_SOURCE_DIR@/test/API/dotest.py"
 config.dotest_args_str = "@LLDB_DOTEST_ARGS@"
 config.lldb_enable_python = @LLDB_ENABLE_PYTHON@
 config.dotest_lit_args_str = None
 config.enabled_plugins = []
 config.lldb_executable = '@LLDB_TEST_EXECUTABLE@'
 config.test_arch = '@LLDB_TEST_ARCH@'
 config.test_compiler = '@LLDB_TEST_COMPILER@'
 config.dsymutil = '@LLDB_TEST_DSYMUTIL@'