[Lldb-commits] [lldb] [llvm] [lldb][RISCV] function calls support in lldb expressions (PR #99336)

[via lldb-commits]

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@@ -164,11 +167,82 @@ TotalArgsSizeInWords(bool is_rv64,
   return total_size;
 }
 
+static bool UpdateRegister(RegisterContext *reg_ctx,
+                           const lldb::RegisterKind reg_kind,
+                           const uint32_t reg_num, const addr_t value) {
+  Log *log = GetLog(LLDBLog::Expressions);
+
+  const RegisterInfo *reg_info = reg_ctx->GetRegisterInfo(reg_kind, reg_num);
+
+  LLDB_LOG(log, "Writing {0}: 0x{1:x}", reg_info->name,
+           static_cast<uint64_t>(value));
+  if (!reg_ctx->WriteRegisterFromUnsigned(reg_info, value)) {
+    LLDB_LOG(log, "Writing {0}: failed", reg_info->name);
+    return false;
+  }
+  return true;
+}
+
+static void LogInitInfo(Log *log, const Thread &thread, addr_t sp,
+                        addr_t func_addr, addr_t return_addr,
+                        const llvm::ArrayRef<addr_t> args) {
+  assert(log);
+  std::stringstream ss;
+  ss << "ABISysV_riscv::PrepareTrivialCall"
+     << " (tid = 0x" << std::hex << thread.GetID() << ", sp = 0x" << sp
+     << ", func_addr = 0x" << func_addr << ", return_addr = 0x" << return_addr;
+
+  for (auto &&[idx, arg] : enumerate(args))
+    ss << ", arg" << std::dec << idx << " = 0x" << std::hex << arg;
+  ss << ")";
+  log->PutString(ss.str());
+}
+
 bool ABISysV_riscv::PrepareTrivialCall(Thread &thread, addr_t sp,
                                        addr_t func_addr, addr_t return_addr,
                                        llvm::ArrayRef<addr_t> args) const {
-  // TODO: Implement
-  return false;
+  Log *log = GetLog(LLDBLog::Expressions);
+  if (log)
+    LogInitInfo(log, thread, sp, func_addr, return_addr, args);
+
+  const auto reg_ctx_sp = thread.GetRegisterContext();
+  if (!reg_ctx_sp) {
+    LLDB_LOG(log, "Failed to get RegisterContext");
+    return false;
+  }
+
+  if (args.size() > s_regs_for_args_count) {
+    LLDB_LOG(log, "Function has {0} arguments, but only {1} are allowed!",
+             args.size(), s_regs_for_args_count);
+    return false;
+  }
+
+  // Write arguments to registers
+  for (auto &&[idx, arg] : enumerate(args)) {
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dlav-sc wrote:

addressed

https://github.com/llvm/llvm-project/pull/99336