[Lldb-commits] [lldb] [lldb][RISCV] Fix GetRegisterInfo to support RISCV-32 (PR #175262)

[via lldb-commits]

https://github.com/MkDev11 updated https://github.com/llvm/llvm-project/pull/175262

>From 9bcd3415b706dac890e67ce2ffe0f98405f91fbf Mon Sep 17 00:00:00 2001
From: mkdev11 <jaysmth689 at gmail.com>
Date: Thu, 15 Jan 2026 02:38:41 +0200
Subject: [PATCH] [lldb][RISCV] Fix GetRegisterInfo to support RISCV-32

GetRegisterInfo in EmulateInstructionRISCV.cpp was hardcoded to use
RegisterInfoPOSIX_riscv64, which caused LLDB to assert when working
with RISCV-32 ELF files.

This patch adds a check for the architecture and uses
RegisterInfoPOSIX_riscv32 when the target is RISCV-32.

Fixes #175092
---
 .../RISCV/EmulateInstructionRISCV.cpp         | 23 +++++++++++++++----
 .../Instruction/RISCV/TestRISCVEmulator.cpp   | 17 ++++++++++++++
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/lldb/source/Plugins/Instruction/RISCV/EmulateInstructionRISCV.cpp b/lldb/source/Plugins/Instruction/RISCV/EmulateInstructionRISCV.cpp
index 2957cb716041d..4f4e6779072d2 100644
--- a/lldb/source/Plugins/Instruction/RISCV/EmulateInstructionRISCV.cpp
+++ b/lldb/source/Plugins/Instruction/RISCV/EmulateInstructionRISCV.cpp
@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "EmulateInstructionRISCV.h"
+#include "Plugins/Process/Utility/RegisterInfoInterface.h"
+#include "Plugins/Process/Utility/RegisterInfoPOSIX_riscv32.h"
 #include "Plugins/Process/Utility/RegisterInfoPOSIX_riscv64.h"
 #include "Plugins/Process/Utility/lldb-riscv-register-enums.h"
 #include "RISCVCInstructions.h"
@@ -1837,10 +1839,23 @@ EmulateInstructionRISCV::GetRegisterInfo(RegisterKind reg_kind,
     }
   }
 
-  RegisterInfoPOSIX_riscv64 reg_info(m_arch,
-                                     RegisterInfoPOSIX_riscv64::eRegsetMaskAll);
-  const RegisterInfo *array = reg_info.GetRegisterInfo();
-  const uint32_t length = reg_info.GetRegisterCount();
+  std::unique_ptr<RegisterInfoInterface> reg_info;
+  switch (m_arch.GetTriple().getArch()) {
+  case llvm::Triple::riscv32:
+    reg_info = std::make_unique<RegisterInfoPOSIX_riscv32>(
+        m_arch, RegisterInfoPOSIX_riscv32::eRegsetMaskAll);
+    break;
+  case llvm::Triple::riscv64:
+    reg_info = std::make_unique<RegisterInfoPOSIX_riscv64>(
+        m_arch, RegisterInfoPOSIX_riscv64::eRegsetMaskAll);
+    break;
+  default:
+    assert(false && "unsupported triple");
+    return {};
+  }
+
+  const RegisterInfo *array = reg_info->GetRegisterInfo();
+  const uint32_t length = reg_info->GetRegisterCount();
 
   if (reg_index >= length || reg_kind != eRegisterKindLLDB)
     return {};
diff --git a/lldb/unittests/Instruction/RISCV/TestRISCVEmulator.cpp b/lldb/unittests/Instruction/RISCV/TestRISCVEmulator.cpp
index 90d5a7c4f3b97..f713755c77a7c 100644
--- a/lldb/unittests/Instruction/RISCV/TestRISCVEmulator.cpp
+++ b/lldb/unittests/Instruction/RISCV/TestRISCVEmulator.cpp
@@ -16,6 +16,7 @@
 #include "lldb/Utility/RegisterValue.h"
 
 #include "Plugins/Instruction/RISCV/EmulateInstructionRISCV.h"
+#include "Plugins/Process/Utility/RegisterInfoPOSIX_riscv32.h"
 #include "Plugins/Process/Utility/RegisterInfoPOSIX_riscv64.h"
 #include "Plugins/Process/Utility/lldb-riscv-register-enums.h"
 
@@ -806,3 +807,19 @@ TEST_F(RISCVEmulatorTester, TestFMV_D_XInst) {
   ASSERT_TRUE(this->Execute(*decode, false));
   ASSERT_EQ(this->fpr.fpr[DecodeRD(FMV_D_XInst)], bits);
 }
+
+TEST_F(RISCVEmulatorTester, TestGetRegisterInfoRV64) {
+  // Test that GetRegisterInfo returns valid register info for riscv64.
+  auto reg_info = this->GetRegisterInfo(eRegisterKindLLDB, gpr_x1_riscv);
+  ASSERT_TRUE(reg_info.has_value());
+  ASSERT_EQ(reg_info->byte_size, 8u);
+  ASSERT_STREQ(reg_info->name, "ra");
+}
+
+TEST_F(RISCVEmulatorTester32, TestGetRegisterInfoRV32) {
+  // Test that GetRegisterInfo returns valid register info for riscv32.
+  auto reg_info = this->GetRegisterInfo(eRegisterKindLLDB, gpr_x1_riscv);
+  ASSERT_TRUE(reg_info.has_value());
+  ASSERT_EQ(reg_info->byte_size, 4u);
+  ASSERT_STREQ(reg_info->name, "ra");
+}