[lldb][AArch64] Automatically add all extensions to disassembler

[DavidSpickett]

Summary

This means we don't have to remember to update this code as much.

This is all tested in lldb/test/Shell/Commands/command-disassemble-aarch64-extensions.s
which I added previously.

We don't have a way to get the latest base architecture yet
so that remains manual. Having all the extensions specified
will probably be equivalent to the latest architecture version
in any case.

[DavidSpickett]

@labath This addresses (most of) what you asked about in https://reviews.llvm.org/D121999. The architecture revision is still manual but given how lax llvm is about allowing any extension on any arch I don't think we'll have a problem. Anyway, it's a step forward.

getExtensionFeatures was incomplete but I fixed that in https://reviews.llvm.org/D123296.

[labath]

This is great. Thanks for doing that.

lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp

1190

If you use features_str as the initial accumulator value, then I'd expect you shouldn't need to use += on the line above. Otherwise, you'd get the +v9.3a bit twice.

But I'd just say features_str += llvm::join(features, ","); instead...

[DavidSpickett]

Use llvm::join.

lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp

 //===-- DisassemblerLLVMC.cpp ---------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "DisassemblerLLVMC.h"
 
 #include "llvm-c/Disassembler.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 #include "llvm/MC/MCDisassembler/MCExternalSymbolizer.h"
 #include "llvm/MC/MCDisassembler/MCRelocationInfo.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCInstPrinter.h"
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/MC/TargetRegistry.h"
+#include "llvm/Support/AArch64TargetParser.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ScopedPrinter.h"
 #include "llvm/Support/TargetSelect.h"
 
 #include "lldb/Core/Address.h"
 #include "lldb/Core/Module.h"
 #include "lldb/Symbol/SymbolContext.h"
 #include "lldb/Target/ExecutionContext.h"
 #include "lldb/Target/Process.h"
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Target/SectionLoadList.h"
 #include "lldb/Target/StackFrame.h"
 #include "lldb/Target/Target.h"
 #include "lldb/Utility/DataExtractor.h"
 #include "lldb/Utility/LLDBLog.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/RegularExpression.h"
 #include "lldb/Utility/Stream.h"
 
+#include <numeric>
+
 using namespace lldb;
 using namespace lldb_private;
 
 LLDB_PLUGIN_DEFINE(DisassemblerLLVMC)
 
 class DisassemblerLLVMC::MCDisasmInstance {
 public:
   static std::unique_ptr<MCDisasmInstance>
if (arch.IsMIPS()) {
     if (arch_flags & ArchSpec::eMIPSAse_msa)
       features_str += "+msa,";
     if (arch_flags & ArchSpec::eMIPSAse_dsp)
       features_str += "+dsp,";
     if (arch_flags & ArchSpec::eMIPSAse_dspr2)
       features_str += "+dspr2,";
   }
 
-  // If any AArch64 variant, enable latest ISA with any optional
-  // extensions like MTE.
+  // If any AArch64 variant, enable latest ISA with all extensions.
   if (triple.isAArch64()) {
-    features_str += "+v9.3a,+mte,+sm4,+sha2,+sha3,+aes,+fp16fml,+sve2-aes,+"
-                    "sve2-sm4,+sve2-sha3,+sve2-bitperm,+f32mm,+f64mm,+tme,+"
-                    "ls64,+sme,+sme-f64,+sme-i64,+spe,+rand,+brbe";
+    features_str += "+v9.3a,";
+    std::vector<llvm::StringRef> features;
+    // Get all possible features
+    llvm::AArch64::getExtensionFeatures(-1, features);
+    features_str +=
+        std::accumulate(features.begin(), features.end(), features_str,
+                        [](std::string features, llvm::StringRef feature) {
+                          return features + feature.str() + ",";
+                        });
 
     if (triple.getVendor() == llvm::Triple::Apple)
       cpu = "apple-latest";
   }
 
   if (triple.isRISCV()) {
     uint32_t arch_flags = arch.GetFlags();
     if (arch_flags & ArchSpec::eRISCV_rvc)