[lldb] [ABI/AArch64] Recognize special regs by their xN names too

[mgorny]

Summary

Recognize lr/sp/fp by their numeric register names in the ABI plugin.
This is necessary to mark them appropriately when interfacing with
gdbserver.

[labath]

seems reasonable

[mgorny]

@labath, the tests here require D109272, as otherwise LLDB won't recognize the architecture correctly. If you review that one, I can rebase its tests not to require other patches and merge these two.

lldb/source/Plugins/ABI/AArch64/ABIAArch64.cpp

std::string ABIAArch64::GetMCName(std::string reg) {
   MapRegisterName(reg, "v", "q");
   MapRegisterName(reg, "x29", "fp");
   MapRegisterName(reg, "x30", "lr");
   return reg;
 }
 uint32_t ABIAArch64::GetGenericNum(llvm::StringRef name) {
   return llvm::StringSwitch<uint32_t>(name)
       .Case("pc", LLDB_REGNUM_GENERIC_PC)
-      .Case("lr", LLDB_REGNUM_GENERIC_RA)
-      .Case("sp", LLDB_REGNUM_GENERIC_SP)
-      .Case("fp", LLDB_REGNUM_GENERIC_FP)
+      .Cases("lr", "x30", LLDB_REGNUM_GENERIC_RA)
+      .Cases("sp", "x31", LLDB_REGNUM_GENERIC_SP)
+      .Cases("fp", "x29", LLDB_REGNUM_GENERIC_FP)
       .Case("cpsr", LLDB_REGNUM_GENERIC_FLAGS)
       .Case("x0", LLDB_REGNUM_GENERIC_ARG1)
       .Case("x1", LLDB_REGNUM_GENERIC_ARG2)
       .Case("x2", LLDB_REGNUM_GENERIC_ARG3)
       .Case("x3", LLDB_REGNUM_GENERIC_ARG4)
       .Case("x4", LLDB_REGNUM_GENERIC_ARG5)
       .Case("x5", LLDB_REGNUM_GENERIC_ARG6)
       .Case("x6", LLDB_REGNUM_GENERIC_ARG7)
       .Case("x7", LLDB_REGNUM_GENERIC_ARG8)
       .Default(LLDB_INVALID_REGNUM);
 }

lldb/test/API/functionalities/gdb_remote_client/TestGDBServerTargetXML.py

def test_aarch64_regs(self):
         self.match("register read cpsr",
                    ["cpsr = 0x74737271"])
 
         # test generic aliases
         self.match("register read arg1",
                    ["x0 = 0x0807060504030201"])
         self.match("register read arg2",
                    ["x1 = 0x1817161514131211"])
+        self.match("register read fp",
+                   ["x29 = 0x3837363534333231"])
+        self.match("register read lr",
+                   ["x30 = 0x4847464544434241"])
+        self.match("register read ra",
+                   ["x30 = 0x4847464544434241"])
         self.match("register read flags",
                    ["cpsr = 0x74737271"])