[Lldb-commits] [lldb] [lldb] Fix feature format in DisassemblerLLVMC constructor (PR #184355)

[Georgiy Samoylov via lldb-commits]

https://github.com/sga-sc created https://github.com/llvm/llvm-project/pull/184355

At this moment feature string in `DisassemblerLLVMC` constructor for example for RISC-V architecture can be something like `+m,+f,+d,+a,+m,`. Last comma at this string is redundant judging by this comment https://github.com/llvm/llvm-project/blob/c9d065abc15846deb95a23fb0b3e1855d3d26314/llvm/include/llvm/TargetParser/SubtargetFeature.h#L167-L174

This patch is also needed for successful test passing in https://github.com/llvm/llvm-project/pull/180943

>From 8501306a6f482387458aad224cf45ea348d4c1ff Mon Sep 17 00:00:00 2001
From: Georgiy Samoylov <g.samoylov at syntacore.com>
Date: Tue, 3 Mar 2026 16:11:01 +0300
Subject: [PATCH] [lldb] Delete last comma from features

---
 .../Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp      | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp b/lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp
index 6384b5e1bb57c..36329e40ab8a2 100644
--- a/lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp
+++ b/lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp
@@ -1617,6 +1617,10 @@ DisassemblerLLVMC::DisassemblerLLVMC(const ArchSpec &arch,
     }
   }
 
+  // We should delete the last comma from string
+  if (!features_str.empty() && features_str.back() == ',')
+    features_str.pop_back();
+
   // We use m_disasm_up.get() to tell whether we are valid or not, so if this
   // isn't good for some reason, we won't be valid and FindPlugin will fail and
   // we won't get used.
@@ -1638,9 +1642,9 @@ DisassemblerLLVMC::DisassemblerLLVMC(const ArchSpec &arch,
     /* Create alternate disassembler for MIPS16 and microMIPS */
     uint32_t arch_flags = arch.GetFlags();
     if (arch_flags & ArchSpec::eMIPSAse_mips16)
-      features_str += "+mips16,";
+      features_str += ",+mips16";
     else if (arch_flags & ArchSpec::eMIPSAse_micromips)
-      features_str += "+micromips,";
+      features_str += ",+micromips";
 
     m_alternate_disasm_up = MCDisasmInstance::Create(
         triple_str, cpu, features_str.c_str(), flavor, *this);