[lldb/Lua] Redirect Lua stdout/stderr to the CommandReturnObject

[JDevlieghere]

Summary

Redirect the output of stdout and stderr to the CommandReturnObject for one line commands.

[JDevlieghere]

Rebase

[labath]

lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp

77

I wonder if we should just pass options.GetEnableIO() to the factory function, and let it figure out the details...

lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp

 #include "Lua.h"
 #include "lldb/Core/Debugger.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Core/StreamFile.h"
 #include "lldb/Interpreter/CommandReturnObject.h"
 #include "lldb/Utility/Stream.h"
 #include "lldb/Utility/StringList.h"
 #include "lldb/Utility/Timer.h"
+#include "llvm/Support/FormatAdapters.h"
 
 using namespace lldb;
 using namespace lldb_private;
 
 LLDB_PLUGIN_DEFINE(ScriptInterpreterLua)
 
 class IOHandlerLuaInterpreter : public IOHandlerDelegate,
                                 public IOHandlerEditline {
ScriptInterpreterLua::ScriptInterpreterLua(Debugger &debugger)
     : ScriptInterpreter(debugger, eScriptLanguageLua),
       m_lua(std::make_unique<Lua>()) {}
 
 ScriptInterpreterLua::~ScriptInterpreterLua() {}
 
 bool ScriptInterpreterLua::ExecuteOneLine(llvm::StringRef command,
                                           CommandReturnObject *result,
                                           const ExecuteScriptOptions &options) {
+  if (command.empty()) {
+    if (result)
+      result->AppendError("empty command passed to lua\n");
+    return false;
+  }
+
+  llvm::Expected<std::unique_ptr<ScriptInterpreterIORedirect>>
+      io_redirect_or_error = ScriptInterpreterIORedirect::Create(
+          options.GetEnableIO(), m_debugger, result);
+  if (!io_redirect_or_error) {
+    if (result)
+      result->AppendErrorWithFormatv(
+          "failed to redirect I/O: {0}\n",
+          llvm::fmt_consume(io_redirect_or_error.takeError()));
+    else
+      llvm::consumeError(io_redirect_or_error.takeError());
+    return false;
+  }
+
+  ScriptInterpreterIORedirect &io_redirect = **io_redirect_or_error;
+
+  if (llvm::Error e =
+          m_lua->ChangeIO(io_redirect.GetOutputFile()->GetStream(),
+                          io_redirect.GetErrorFile()->GetStream())) {
+    result->AppendErrorWithFormatv("lua failed to redirect I/O: {0}\n",
+                                   llvm::toString(std::move(e)));
+    return false;
+  }
+
   if (llvm::Error e = m_lua->Run(command)) {
     result->AppendErrorWithFormatv(
         "lua failed attempting to evaluate '{0}': {1}\n", command,
         llvm::toString(std::move(e)));
     return false;
   }
+
+  io_redirect.Flush();
   return true;
 }
 
 void ScriptInterpreterLua::ExecuteInterpreterLoop() {
   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
   Timer scoped_timer(func_cat, LLVM_PRETTY_FUNCTION);
 
   // At the moment, the only time the debugger does not have an input file

lldb/test/Shell/ScriptInterpreter/Lua/io.test

 # REQUIRES: lua
 # UNSUPPORTED: lldb-repro
 #
+# RUN: rm -rf %t.stderr %t.stdout
 # RUN: cat %s | %lldb --script-language lua 2> %t.stderr > %t.stdout
 # RUN: cat %t.stdout | FileCheck %s --check-prefix STDOUT
 # RUN: cat %t.stderr | FileCheck %s --check-prefix STDERR
 script
 file = lldb.SBFile(2, "w", false)
 lldb.debugger:SetOutputFile(file)
 io.write(95000 + 126, "\n")
 quit
 script
 io.write(95000 + 14, "\n")
+
 # STDOUT: 95126
 # STDOUT-NOT: 95014
 # STDERR: 95014
+
+# RUN: rm -rf %t.stderr %t.stdout
+# RUN: %lldb --script-language lua -o 'script io.stderr:write(95000 + 126, "\n")' 2> %t.stderr > %t.stdout
+# RUN: cat %t.stdout | FileCheck %s --check-prefix STDOUT