[Lldb-commits] [lldb] [lldb][debugserver] Read/write SME registers on arm64 (PR #119171)

[David Spickett via lldb-commits]

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@@ -0,0 +1,163 @@
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+import os
+
+
+class TestSMERegistersDarwin(TestBase):
+    NO_DEBUG_INFO_TESTCASE = True
+    mydir = TestBase.compute_mydir(__file__)
+
+    @skipIfRemote
+    @skipUnlessDarwin
+    @skipUnlessFeature("hw.optional.arm.FEAT_SME")
+    @skipUnlessFeature("hw.optional.arm.FEAT_SME2")
+    # thread_set_state/thread_get_state only avail in macOS 15.4+
+    @skipIf(macos_version=["<", "15.4"])
+    def test(self):
+        """Test that we can read the contents of the SME/SVE registers on Darwin"""
+        self.build()
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.c")
+        )
+        frame = thread.GetFrameAtIndex(0)
+        self.assertTrue(frame.IsValid())
+
+        if self.TraceOn():
+            self.runCmd("reg read -a")
+
+        svl_reg = frame.register["svl"]
+        svl = svl_reg.GetValueAsUnsigned()
+
+        # SSVE and SME modes should be enabled (reflecting PSTATE.SM and PSTATE.ZA)
+        svcr = frame.register["svcr"]
+        self.assertEqual(svcr.GetValueAsUnsigned(), 3)
+
+        z0 = frame.register["z0"]
+        self.assertEqual(z0.GetNumChildren(), svl)
+        self.assertEqual(z0.GetChildAtIndex(0).GetValueAsUnsigned(), 0x1)
+        self.assertEqual(z0.GetChildAtIndex(svl - 1).GetValueAsUnsigned(), 0x1)
+
+        z31 = frame.register["z31"]
+        self.assertEqual(z31.GetNumChildren(), svl)
+        self.assertEqual(z31.GetChildAtIndex(0).GetValueAsUnsigned(), 32)
+        self.assertEqual(z31.GetChildAtIndex(svl - 1).GetValueAsUnsigned(), 32)
+
+        p0 = frame.register["p0"]
+        self.assertEqual(p0.GetNumChildren(), svl / 8)
+        self.assertEqual(p0.GetChildAtIndex(0).GetValueAsUnsigned(), 0xFF)
+        self.assertEqual(
+            p0.GetChildAtIndex(p0.GetNumChildren() - 1).GetValueAsUnsigned(), 0xFF
+        )
+
+        p15 = frame.register["p15"]
+        self.assertEqual(p15.GetNumChildren(), svl / 8)
+        self.assertEqual(p15.GetChildAtIndex(0).GetValueAsUnsigned(), 0xFF)
+        self.assertEqual(
+            p15.GetChildAtIndex(p15.GetNumChildren() - 1).GetValueAsUnsigned(), 0xFF
+        )
+
+        za = frame.register["za"]
+        self.assertEqual(za.GetNumChildren(), (svl * svl))
+        za_0 = za.GetChildAtIndex(0)
+        self.assertEqual(za_0.GetValueAsUnsigned(), 4)
+        za_final = za.GetChildAtIndex(za.GetNumChildren() - 1)
+        self.assertEqual(za_final.GetValueAsUnsigned(), 67)
+
+        zt0 = frame.register["zt0"]
+        self.assertEqual(zt0.GetNumChildren(), 64)
+        zt0_0 = zt0.GetChildAtIndex(0)
+        self.assertEqual(zt0_0.GetValueAsUnsigned(), 0)
+        zt0_final = zt0.GetChildAtIndex(63)
+        self.assertEqual(zt0_final.GetValueAsUnsigned(), 63)
+
+        z0_old_values = []
----------------
DavidSpickett wrote:

My brain screams for a refactor of this code but I'm not sure what would not just make it hard to debug if it ever failed.

Could you add a comment at the start of each run of this almost repeated stuff like:
```
# Write each register with a value X more than the current value.
<...>
# Read back the new value, it should be X more ...
```
Then at least reading this is less cryptic. 

https://github.com/llvm/llvm-project/pull/119171