[SystemZ][z/OS] Link library path in libc++ testing

[muiez]

Summary

The functions configure_link_flags_cxx_library_path & configure_link_flags_abi_library_path are not handling the z/OS specific case correctly when a [cxx|abi]_runtime_root is specified to link. The options are not recognized on z/OS.

Hence, this patch adds a z/OS specific case (similar to the other platform-specific cases) but adds the library path using the LIBPATH env variable. In addition, (add_path) is modified to account for adding the LIBPATH env variable as well.

[ldionne]

I don't understand why this change is necessary, since you folks are using this config libcxx/test/configs/ibm-libc++-shared.cfg.in.

Generally speaking, we're trying to move away from the old config file in libcxx/utils/libcxx/test/config.py. I don't really have an objection to this patch except that it's going to break when we remove libcxx/utils/libcxx/test/config.py, so you should probably set up your testing against the right configuration from the get go.

[muiez]

Will use custom config file instead.

libcxx/utils/libcxx/test/config.py

def configure_link_flags(self):
         self.cxx.link_flags += shlex.split(link_flags_str)
 
     def configure_link_flags_cxx_library_path(self):
         if self.cxx_library_root:
             self.cxx.link_flags += ['-L' + self.cxx_library_root]
             if self.target_info.is_windows() and self.link_shared:
                 self.add_path(self.cxx.compile_env, self.cxx_library_root)
         if self.cxx_runtime_root:
-            if not self.target_info.is_windows():
+            if self.target_info.is_zos():
+                self.add_path(self.exec_env, self.cxx_runtime_root, is_libpath=True)
+            elif not self.target_info.is_windows():
                 self.cxx.link_flags += ['-Wl,-rpath,' +
                                         self.cxx_runtime_root]
             elif self.target_info.is_windows() and self.link_shared:
                 self.add_path(self.exec_env, self.cxx_runtime_root)
         additional_flags = self.get_lit_conf('test_linker_flags')
         if additional_flags:
             self.cxx.link_flags += shlex.split(additional_flags)
 
     def configure_link_flags_abi_library_path(self):
         # Configure ABI library paths.
         if self.abi_library_root:
             self.cxx.link_flags += ['-L' + self.abi_library_root]
         if self.abi_runtime_root:
-            if not self.target_info.is_windows():
+            if self.target_info.is_zos():
+                self.add_path(self.exec_env, self.abi_runtime_root, is_libpath=True)
+            elif not self.target_info.is_windows():
                 self.cxx.link_flags += ['-Wl,-rpath,' + self.abi_runtime_root]
             else:
                 self.add_path(self.exec_env, self.abi_runtime_root)
 
     def configure_link_flags_cxx_library(self):
         if self.link_shared:
             self.cxx.link_flags += ['-lc++']
         else:
def configure_substitutions(self):
             '--codesign_identity "{}"'.format(codesign_ident),
             '--env {}'.format(env_vars)
         ]
         sub.append(('%{exec}', '{} {} -- '.format(self.executor, ' '.join(exec_args))))
 
     def configure_env(self):
         self.config.environment = dict(os.environ)
 
-    def add_path(self, dest_env, new_path):
-        self.target_info.add_path(dest_env, new_path)
+    def add_path(self, dest_env, new_path, is_libpath=False):
+        self.target_info.add_path(dest_env, new_path, is_libpath)

libcxx/utils/libcxx/test/target_info.py

class DefaultTargetInfo(object):
     def is_mingw(self):
         return False
 
     def add_cxx_flags(self, flags): pass
     def add_cxx_compile_flags(self, flags): pass
     def add_cxx_link_flags(self, flags): pass
     def allow_cxxabi_link(self): return True
 
-    def add_path(self, dest_env, new_path):
+    def add_path(self, dest_env, new_path, is_libpath=False):
+        env_var = 'LIBPATH' if is_libpath else 'PATH'
         if not new_path:
             return
-        if 'PATH' not in dest_env:
-            dest_env['PATH'] = new_path
+        if env_var not in dest_env:
+            dest_env[env_var] = new_path
         else:
             split_char = ';' if self.is_windows() else ':'
-            dest_env['PATH'] = '%s%s%s' % (new_path, split_char,
-                                           dest_env['PATH'])
+            dest_env[env_var] = '%s%s%s' % (new_path, split_char,
+                                           dest_env[env_var])
 
 
 class DarwinLocalTI(DefaultTargetInfo):
     def __init__(self, full_config):
         super(DarwinLocalTI, self).__init__(full_config)
 
     def add_cxx_flags(self, flags):
         out, err, exit_code = executeCommand(['xcrun', '--show-sdk-path'])