[libcxx] Add targets to available features.

[danielkiss]

Summary

This patch add the target-* (x86_64-*) as used elsewhere in llvm.

[danielkiss]

some test never runs due to these features are missing. I realised this when tried to run this one: https://github.com/llvm/llvm-project/blob/master/libunwind/test/remember_state_leak.pass.sh.s#L1

[ldionne]

libcxx/utils/libcxx/test/config.py

269–283

None of these features are used anywhere in the tests as far as I can find. Why add them?

288

Not used in the tests, I would prefer we don't add features just for the sake of having them.

291–303

I think it only makes sense to add those, and the reason is that Lit doesn't allow matching partial triples. We already add the full target triple as a Lit feature, and I think it would be nicer to be able to say something like // REQUIRES: x86_64-linux-* instead of having to add these features. But Lit doesn't do that, so let's add them.

[danielkiss]

The system-* and native are used in clang and lldb only, so dropped.
I only added them for consistency across llvm components.

libcxx/utils/libcxx/test/config.py

def configure_features(self):
                 # using this feature. (Also see llvm.org/PR32730)
                 self.config.available_features.add('LIBCXX-WINDOWS-FIXME')
 
         libcxx_gdb = self.get_lit_conf('libcxx_gdb')
         if libcxx_gdb and 'NOTFOUND' not in libcxx_gdb:
             self.config.available_features.add('libcxx_gdb')
             self.cxx.libcxx_gdb = libcxx_gdb
 
+        target_triple = getattr(self.config, 'target_triple', None)
+        if target_triple:
+            if re.match(r'^x86_64.*-apple', target_triple):
+                self.config.available_features.add('x86_64-apple')
+            if re.match(r'^x86_64.*-linux', target_triple):
+                self.config.available_features.add('x86_64-linux')
+            if re.match(r'^i.86.*', target_triple):
+                self.config.available_features.add('target-x86')
+            elif re.match(r'^x86_64.*', target_triple):
+                self.config.available_features.add('target-x86_64')
+            elif re.match(r'^aarch64.*', target_triple):
+                self.config.available_features.add('target-aarch64')
+            elif re.match(r'^arm.*', target_triple):
+                self.config.available_features.add('target-arm')
+
     def configure_compile_flags(self):
         self.configure_default_compile_flags()
         # Configure extra flags
         compile_flags_str = self.get_lit_conf('compile_flags', '')
         self.cxx.compile_flags += shlex.split(compile_flags_str)
         if self.target_info.is_windows():
             self.cxx.compile_flags += ['-D_CRT_SECURE_NO_WARNINGS']
             # Don't warn about using common but nonstandard unprefixed functions
             # like chdir, fileno.
             self.cxx.compile_flags += ['-D_CRT_NONSTDC_NO_WARNINGS']
             # Required so that tests using min/max don't fail on Windows,
             # and so that those tests don't have to be changed to tolerate
             # this insanity.
             self.cxx.compile_flags += ['-DNOMINMAX']
         additional_flags = self.get_lit_conf('test_compiler_flags')
         if additional_flags:
             self.cxx.compile_flags += shlex.split(additional_flags)
 
     def configure_default_compile_flags(self):
         # Configure include paths
         self.configure_compile_flags_header_includes()
         self.target_info.add_cxx_compile_flags(self.cxx.compile_flags)
         self.target_info.add_cxx_flags(self.cxx.flags)
         # Configure feature flags.
         enable_32bit = self.get_lit_bool('enable_32bit', False)
         if enable_32bit:
             self.cxx.flags += ['-m32']
         # Use verbose output for better errors