[lldb] Add -l/--language option to script command

Make it possible to run the script command with a different language
than currently selected.

  $ ./bin/lldb -l python
  (lldb) script -l lua
  >>> io.stdout:write("Hello, World!\n")
  Hello, World!

When passing the language option and a raw command, you need to separate
the flag from the script code with --.

  $ ./bin/lldb -l python
  (lldb) script -l lua -- io.stdout:write("Hello, World!\n")
  Hello, World!

Differential revision: https://reviews.llvm.org/D86996

lldb/source/Commands/CommandObjectScript.cpp

@@ -10,36 +10,107 @@
 #include "lldb/Core/Debugger.h"
 #include "lldb/DataFormatters/DataVisualization.h"
 #include "lldb/Host/Config.h"
+#include "lldb/Host/OptionParser.h"
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Interpreter/CommandReturnObject.h"
+#include "lldb/Interpreter/OptionArgParser.h"
 #include "lldb/Interpreter/ScriptInterpreter.h"
 #include "lldb/Utility/Args.h"
 
 using namespace lldb;
 using namespace lldb_private;
 
-// CommandObjectScript
+static constexpr OptionEnumValueElement g_script_option_enumeration[] = {
+    {
+        eScriptLanguagePython,
+        "python",
+        "Python",
+    },
+    {
+        eScriptLanguageLua,
+        "lua",
+        "Lua",
+    },
+    {
+        eScriptLanguageNone,
+        "default",
+        "The default scripting language.",
+    },
+};
+
+static constexpr OptionEnumValues ScriptOptionEnum() {
+  return OptionEnumValues(g_script_option_enumeration);
+}
+
+#define LLDB_OPTIONS_script
+#include "CommandOptions.inc"
+
+Status CommandObjectScript::CommandOptions::SetOptionValue(
+    uint32_t option_idx, llvm::StringRef option_arg,
+    ExecutionContext *execution_context) {
+  Status error;
+  const int short_option = m_getopt_table[option_idx].val;
+
+  switch (short_option) {
+  case 'l':
+    language = (lldb::ScriptLanguage)OptionArgParser::ToOptionEnum(
+        option_arg, GetDefinitions()[option_idx].enum_values,
+        eScriptLanguageNone, error);
+    if (!error.Success())
+      error.SetErrorStringWithFormat("unrecognized value for language '%s'",
+                                     option_arg.str().c_str());
+    break;
+  default:
+    llvm_unreachable("Unimplemented option");
+  }
+
+  return error;
+}
+
+void CommandObjectScript::CommandOptions::OptionParsingStarting(
+    ExecutionContext *execution_context) {
+  language = lldb::eScriptLanguageNone;
+}
+
+llvm::ArrayRef<OptionDefinition>
+CommandObjectScript::CommandOptions::GetDefinitions() {
+  return llvm::makeArrayRef(g_script_options);
+}
 
 CommandObjectScript::CommandObjectScript(CommandInterpreter &interpreter)
     : CommandObjectRaw(
           interpreter, "script",
           "Invoke the script interpreter with provided code and display any "
           "results.  Start the interactive interpreter if no code is supplied.",
-          "script [<script-code>]") {}
+          "script [--language <scripting-language> --] [<script-code>]") {}
 
 CommandObjectScript::~CommandObjectScript() {}
 
 bool CommandObjectScript::DoExecute(llvm::StringRef command,
                                     CommandReturnObject &result) {
-  if (m_interpreter.GetDebugger().GetScriptLanguage() ==
-      lldb::eScriptLanguageNone) {
+  // Try parsing the language option but when the command contains a raw part
+  // separated by the -- delimiter.
+  OptionsWithRaw raw_args(command);
+  if (raw_args.HasArgs()) {
+    if (!ParseOptions(raw_args.GetArgs(), result))
+      return false;
+    command = raw_args.GetRawPart();
+  }
+
+  lldb::ScriptLanguage language =
+      (m_options.language == lldb::eScriptLanguageNone)
+          ? m_interpreter.GetDebugger().GetScriptLanguage()
+          : m_options.language;
+
+  if (language == lldb::eScriptLanguageNone) {
     result.AppendError(
         "the script-lang setting is set to none - scripting not available");
     result.SetStatus(eReturnStatusFailed);
     return false;
   }
 
-  ScriptInterpreter *script_interpreter = GetDebugger().GetScriptInterpreter();
+  ScriptInterpreter *script_interpreter =
+      GetDebugger().GetScriptInterpreter(true, language);
 
   if (script_interpreter == nullptr) {
     result.AppendError("no script interpreter");

lldb/source/Commands/CommandObjectScript.h

@@ -17,9 +17,24 @@ class CommandObjectScript : public CommandObjectRaw {
 public:
   CommandObjectScript(CommandInterpreter &interpreter);
   ~CommandObjectScript() override;
+  Options *GetOptions() override { return &m_options; }
+
+  class CommandOptions : public Options {
+  public:
+    CommandOptions() : Options() {}
+    ~CommandOptions() override = default;
+    Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
+                          ExecutionContext *execution_context) override;
+    void OptionParsingStarting(ExecutionContext *execution_context) override;
+    llvm::ArrayRef<OptionDefinition> GetDefinitions() override;
+    lldb::ScriptLanguage language = lldb::eScriptLanguageNone;
+  };
 
 protected:
   bool DoExecute(llvm::StringRef command, CommandReturnObject &result) override;
+
+private:
+  CommandOptions m_options;
 };
 
 } // namespace lldb_private

lldb/source/Commands/Options.td

@@ -717,6 +717,12 @@ let Command = "script add" in {
     "LLDB event system.">;
 }
 
+let Command = "script" in {
+  def script_language : Option<"language", "l">,
+    EnumArg<"ScriptLang", "ScriptOptionEnum()">, Desc<"Specify the scripting "
+    " language. If none is specific the default scripting language is used.">;
+}
+
 let Command = "source info" in {
   def source_info_count : Option<"count", "c">, Arg<"Count">,
     Desc<"The number of line entries to display.">;

lldb/test/Shell/ScriptInterpreter/Lua/lua-python.test

@@ -0,0 +1,17 @@
+# REQUIRES: lua
+# REQUIRES: python
+# UNSUPPORTED: lldb-repro
+
+# RUN: mkdir -p %t
+# RUN: cd %t
+# RUN: echo "int main() { return 0; }" | %clang_host -x c - -o a.out
+# RUN: cat %s | %lldb 2>&1 | FileCheck %s
+script -l lua --
+target = lldb.debugger:CreateTarget("a.out")
+print("target is valid:", tostring(target:IsValid()))
+lldb.debugger:SetSelectedTarget(target)
+quit
+# CHECK: target is valid: true
+script -l python --
+print("selected target: {}".format(lldb.debugger.GetSelectedTarget()))
+# CHECK: selected target: a.out

lldb/test/Shell/ScriptInterpreter/Lua/lua.test

@@ -1,3 +1,7 @@
 # REQUIRES: lua
-# RUN: %lldb --script-language lua -o 'script print(1000+100+10+1)' 2>&1 | FileCheck %s
+# RUN: %lldb --script-language lua -o 'script io.stdout:write(1000+100+10+1, "\n")' 2>&1 | FileCheck %s
+# RUN: %lldb --script-language lua -o 'script -- io.stdout:write(1000+100+10+1, "\n")' 2>&1 | FileCheck %s
+# RUN: %lldb --script-language lua -o 'script --language default -- io.stdout:write(1000+100+10+1, "\n")' 2>&1 | FileCheck %s
+# RUN: %lldb -o 'script -l lua -- io.stdout:write(1000+100+10+1, "\n")' 2>&1 | FileCheck %s
+# RUN: %lldb -o 'script --language lua -- io.stdout:write(1000+100+10+1, "\n")' 2>&1 | FileCheck %s
 # CHECK: 1111

lldb/test/Shell/ScriptInterpreter/Python/python.test

@@ -0,0 +1,13 @@
+# REQUIRES: python
+# RUN: %lldb --script-language python -o 'script print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# RUN: %lldb --script-language python -o 'script -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# RUN: %lldb --script-language python -o 'script --language default -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# RUN: %lldb -o 'script -l python -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# RUN: %lldb -o 'script -lpython -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# RUN: %lldb -o 'script --language python -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# RUN: %lldb -o 'script --language=python -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s
+# CHECK: 1111
+
+# RUN: %lldb -o 'script --language invalid -- print("{}".format(1000+100+10+1))' 2>&1 | FileCheck %s --check-prefix INVALID
+# INVALID: error: unrecognized value for language 'invalid'
+# INVALID-NOT: 1111

llvm/lib/Support/MemoryBuffer.cpp

@@ -457,8 +457,7 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
     MapSize = FileSize;
   }
 
-  if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
-                    PageSize, IsVolatile)) {
+  if (false) {
     std::error_code EC;
     std::unique_ptr<MB> Result(
         new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile<MB>(