[lldb] [test] Fix qRegisterInfo lldb-server test to handle missing registers

[mgorny]

Summary

Fix qRegisterInfo tests to handle Exx error response when querying
registers that are not supported on the platform in question. This
is how FreeBSD and NetBSD platforms reporting missing registers right
now, and there certainly is value from verifying the remaining
registers.

This change fixes the test for FreeBSD but NetBSD has other regressions
that still need to be researched.

[labath]

Looks good. I'd rephrase the commit title to make it clearer this only changes the single test, and does not change behavior otherwise...

lldb/test/API/tools/lldb-server/TestLldbGdbServer.py

588

Maybe add a TODO to remove this once we're able to actually make registers disappear.

[mgorny]

Ok, will add the comment and push.

lldb/test/API/tools/lldb-server/TestLldbGdbServer.py

def p_returns_correct_data_size_for_each_qRegisterInfo(self):
                 True)
             context = self.expect_gdbremote_sequence()
             self.assertIsNotNone(context)
 
             # Verify the response length.
             p_response = context.get("p_response")
             self.assertIsNotNone(p_response)
 
+            # Skip erraneous (unsupported) registers.
+            # TODO: remove this once we make unsupported registers disappear.
+            if p_response.startswith("E") and len(p_response) == 3:
+                continue
+
             if "dynamic_size_dwarf_expr_bytes" in reg_info:
                 self.updateRegInfoBitsize(reg_info, byte_order)
-            self.assertEqual(len(p_response), 2 * int(reg_info["bitsize"]) / 8)
+            self.assertEqual(len(p_response), 2 * int(reg_info["bitsize"]) / 8,
+                             reg_info)
 
             # Increment loop
             reg_index += 1
 
     @debugserver_test
     @skipIfDarwinEmbedded # <rdar://problem/34539270> lldb-server tests not updated to work on ios etc yet
     def test_p_returns_correct_data_size_for_each_qRegisterInfo_launch_debugserver(
             self):
         self.init_debugserver_test()
         self.build()
         self.set_inferior_startup_launch()
         self.p_returns_correct_data_size_for_each_qRegisterInfo()
 
-    @expectedFailureAll(oslist=["freebsd", "netbsd"])
+    @expectedFailureAll(oslist=["netbsd"])
     @llgs_test
     def test_p_returns_correct_data_size_for_each_qRegisterInfo_launch_llgs(
             self):
         self.init_llgs_test()
         self.build()
         self.set_inferior_startup_launch()
         self.p_returns_correct_data_size_for_each_qRegisterInfo()
 
     @debugserver_test
     @skipIfDarwinEmbedded # <rdar://problem/34539270> lldb-server tests not updated to work on ios etc yet
     def test_p_returns_correct_data_size_for_each_qRegisterInfo_attach_debugserver(
             self):
         self.init_debugserver_test()
         self.build()
         self.set_inferior_startup_attach()
         self.p_returns_correct_data_size_for_each_qRegisterInfo()
 
-    @expectedFailureAll(oslist=["freebsd", "netbsd"])
+    @expectedFailureAll(oslist=["netbsd"])
     @llgs_test
     def test_p_returns_correct_data_size_for_each_qRegisterInfo_attach_llgs(
             self):
         self.init_llgs_test()
         self.build()
         self.set_inferior_startup_attach()
         self.p_returns_correct_data_size_for_each_qRegisterInfo()