Convert various CommandInterpreter functions to StringRef.

llvm-svn: 283370

7 files changed, 237 insertions, 247 deletions

diff --git a/lldb/source/Commands/CommandObjectArgs.cpp b/lldb/source/Commands/CommandObjectArgs.cpp
index 59b9c5aff8b..caf09974aa5 100644
--- a/lldb/source/Commands/CommandObjectArgs.cpp
+++ b/lldb/source/Commands/CommandObjectArgs.cpp
@@ -29,6 +29,8 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
 
+#include "llvm/ADT/StringSwitch.h"
+
 using namespace lldb;
 using namespace lldb_private;
 
@@ -101,10 +103,7 @@ bool CommandObjectArgs::DoExecute(Args &args, CommandReturnObject &result) {
     return false;
   }
 
-  const size_t num_args = args.GetArgumentCount();
-  size_t arg_index;
-
-  if (!num_args) {
+  if (args.empty()) {
     result.AppendError("args requires at least one argument");
     result.SetStatus(eReturnStatusFailed);
     return false;
@@ -143,73 +142,71 @@ bool CommandObjectArgs::DoExecute(Args &args, CommandReturnObject &result) {
 
   ValueList value_list;
 
-  for (arg_index = 0; arg_index < num_args; ++arg_index) {
-    const char *arg_type_cstr = args.GetArgumentAtIndex(arg_index);
+  for (auto &arg_entry : args.entries()) {
+    llvm::StringRef arg_type = arg_entry.ref;
     Value value;
     value.SetValueType(Value::eValueTypeScalar);
     CompilerType compiler_type;
 
-    char *int_pos;
-    if ((int_pos = strstr(const_cast<char *>(arg_type_cstr), "int"))) {
+    llvm::StringRef int_type = arg_type;
+    std::size_t int_pos = arg_type.find("int");
+    if (int_pos != llvm::StringRef::npos) {
       Encoding encoding = eEncodingSint;
 
       int width = 0;
 
-      if (int_pos > arg_type_cstr + 1) {
-        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
+      if (int_pos > 1) {
+        result.AppendErrorWithFormat("Invalid format: %s.\n",
+                                     arg_entry.c_str());
         result.SetStatus(eReturnStatusFailed);
         return false;
       }
-      if (int_pos == arg_type_cstr + 1 && arg_type_cstr[0] != 'u') {
-        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
+      if (int_pos == 1 && arg_type[0] != 'u') {
+        result.AppendErrorWithFormat("Invalid format: %s.\n",
+                                     arg_entry.c_str());
         result.SetStatus(eReturnStatusFailed);
         return false;
       }
-      if (arg_type_cstr[0] == 'u') {
+      if (arg_type[0] == 'u') {
         encoding = eEncodingUint;
       }
 
-      char *width_pos = int_pos + 3;
-
-      if (!strcmp(width_pos, "8_t"))
-        width = 8;
-      else if (!strcmp(width_pos, "16_t"))
-        width = 16;
-      else if (!strcmp(width_pos, "32_t"))
-        width = 32;
-      else if (!strcmp(width_pos, "64_t"))
-        width = 64;
-      else {
-        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
+      llvm::StringRef width_spec = arg_type.drop_front(int_pos + 3);
+
+      auto exp_result = llvm::StringSwitch<llvm::Optional<int>>(width_spec)
+                            .Case("8_t", 8)
+                            .Case("16_t", 16)
+                            .Case("32_t", 32)
+                            .Case("64_t", 64)
+                            .Default(llvm::None);
+      if (!exp_result.hasValue()) {
+        result.AppendErrorWithFormat("Invalid format: %s.\n",
+                                     arg_entry.c_str());
         result.SetStatus(eReturnStatusFailed);
         return false;
       }
+      width = *exp_result;
+
       compiler_type =
           type_system->GetBuiltinTypeForEncodingAndBitSize(encoding, width);
 
       if (!compiler_type.IsValid()) {
         result.AppendErrorWithFormat(
             "Couldn't get Clang type for format %s (%s integer, width %d).\n",
-            arg_type_cstr, (encoding == eEncodingSint ? "signed" : "unsigned"),
-            width);
+            arg_entry.c_str(),
+            (encoding == eEncodingSint ? "signed" : "unsigned"), width);
 
         result.SetStatus(eReturnStatusFailed);
         return false;
       }
-    } else if (strchr(arg_type_cstr, '*')) {
-      if (!strcmp(arg_type_cstr, "void*"))
-        compiler_type =
-            type_system->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType();
-      else if (!strcmp(arg_type_cstr, "char*"))
-        compiler_type =
-            type_system->GetBasicTypeFromAST(eBasicTypeChar).GetPointerType();
-      else {
-        result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
-        result.SetStatus(eReturnStatusFailed);
-        return false;
-      }
+    } else if (arg_type == "void*") {
+      compiler_type =
+          type_system->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType();
+    } else if (arg_type == "char*") {
+      compiler_type =
+          type_system->GetBasicTypeFromAST(eBasicTypeChar).GetPointerType();
     } else {
-      result.AppendErrorWithFormat("Invalid format: %s.\n", arg_type_cstr);
+      result.AppendErrorWithFormat("Invalid format: %s.\n", arg_entry.c_str());
       result.SetStatus(eReturnStatusFailed);
       return false;
     }
@@ -226,10 +223,10 @@ bool CommandObjectArgs::DoExecute(Args &args, CommandReturnObject &result) {
 
   result.GetOutputStream().Printf("Arguments : \n");
 
-  for (arg_index = 0; arg_index < num_args; ++arg_index) {
-    result.GetOutputStream().Printf("%" PRIu64 " (%s): ", (uint64_t)arg_index,
-                                    args.GetArgumentAtIndex(arg_index));
-    value_list.GetValueAtIndex(arg_index)->Dump(&result.GetOutputStream());
+  for (auto entry : llvm::enumerate(args.entries())) {
+    result.GetOutputStream().Printf("%" PRIu64 " (%s): ", (uint64_t)entry.Index,
+                                    entry.Value.c_str());
+    value_list.GetValueAtIndex(entry.Index)->Dump(&result.GetOutputStream());
     result.GetOutputStream().Printf("\n");
   }
 
diff --git a/lldb/source/Commands/CommandObjectBreakpoint.cpp b/lldb/source/Commands/CommandObjectBreakpoint.cpp
index 4202068c680..e9776985b6d 100644
--- a/lldb/source/Commands/CommandObjectBreakpoint.cpp
+++ b/lldb/source/Commands/CommandObjectBreakpoint.cpp
@@ -1113,7 +1113,7 @@ protected:
       return false;
     }
 
-    if (command.GetArgumentCount() == 0) {
+    if (command.empty()) {
       // No breakpoint selected; enable all currently set breakpoints.
       target->EnableAllBreakpoints();
       result.AppendMessageWithFormat("All breakpoints enabled. (%" PRIu64
@@ -1226,7 +1226,7 @@ protected:
       return false;
     }
 
-    if (command.GetArgumentCount() == 0) {
+    if (command.empty()) {
       // No breakpoint selected; disable all currently set breakpoints.
       target->DisableAllBreakpoints();
       result.AppendMessageWithFormat("All breakpoints disabled. (%" PRIu64
@@ -1400,7 +1400,7 @@ protected:
 
     Stream &output_stream = result.GetOutputStream();
 
-    if (command.GetArgumentCount() == 0) {
+    if (command.empty()) {
       // No breakpoint selected; show info about all currently set breakpoints.
       result.AppendMessage("Current breakpoints:");
       for (size_t i = 0; i < num_breakpoints; ++i) {
@@ -1693,7 +1693,7 @@ protected:
       return false;
     }
 
-    if (command.GetArgumentCount() == 0) {
+    if (command.empty()) {
       if (!m_options.m_force &&
           !m_interpreter.Confirm(
               "About to delete all breakpoints, do you want to do that?",
@@ -2295,7 +2295,7 @@ protected:
     target->GetBreakpointList().GetListMutex(lock);
 
     BreakpointIDList valid_bp_ids;
-    if (command.GetArgumentCount() > 0) {
+    if (!command.empty()) {
       CommandObjectMultiwordBreakpoint::VerifyBreakpointIDs(
           command, target, result, &valid_bp_ids);
 
@@ -2397,7 +2397,7 @@ void CommandObjectMultiwordBreakpoint::VerifyIDs(Args &args, Target *target,
 
   Args temp_args;
 
-  if (args.GetArgumentCount() == 0) {
+  if (args.empty()) {
     if (target->GetLastCreatedBreakpoint()) {
       valid_ids->AddBreakpointID(BreakpointID(
           target->GetLastCreatedBreakpoint()->GetID(), LLDB_INVALID_BREAK_ID));
diff --git a/lldb/source/Commands/CommandObjectBreakpointCommand.cpp b/lldb/source/Commands/CommandObjectBreakpointCommand.cpp
index 1d2d6a1dd2b..ab9ed3fb8b6 100644
--- a/lldb/source/Commands/CommandObjectBreakpointCommand.cpp
+++ b/lldb/source/Commands/CommandObjectBreakpointCommand.cpp
@@ -562,7 +562,7 @@ protected:
       return false;
     }
 
-    if (command.GetArgumentCount() == 0) {
+    if (command.empty()) {
       result.AppendError(
           "No breakpoint specified from which to delete the commands");
       result.SetStatus(eReturnStatusFailed);
@@ -653,7 +653,7 @@ protected:
       return false;
     }
 
-    if (command.GetArgumentCount() == 0) {
+    if (command.empty()) {
       result.AppendError(
           "No breakpoint specified for which to list the commands");
       result.SetStatus(eReturnStatusFailed);
diff --git a/lldb/source/Commands/CommandObjectCommands.cpp b/lldb/source/Commands/CommandObjectCommands.cpp
index 1686c21b575..0c07fd81035 100644
--- a/lldb/source/Commands/CommandObjectCommands.cpp
+++ b/lldb/source/Commands/CommandObjectCommands.cpp
@@ -306,9 +306,8 @@ protected:
   };
 
   bool DoExecute(Args &command, CommandReturnObject &result) override {
-    const size_t argc = command.GetArgumentCount();
-    if (argc == 1) {
-      const char *filename = command.GetArgumentAtIndex(0);
+    if (command.GetArgumentCount() == 1) {
+      llvm::StringRef filename = command.GetArgumentAtIndex(0);
 
       FileSpec cmd_file(filename, true);
       ExecutionContext *exe_ctx = nullptr; // Just use the default context.
@@ -600,9 +599,7 @@ protected:
     std::string raw_command_string(remainder);
     Args args(raw_command_string.c_str());
 
-    size_t argc = args.GetArgumentCount();
-
-    if (argc < 2) {
+    if (args.GetArgumentCount() < 2) {
       result.AppendError("'command alias' requires at least two arguments");
       result.SetStatus(eReturnStatusFailed);
       return false;
@@ -610,6 +607,8 @@ protected:
 
     // Get the alias command.
 
+    // TODO: Convert this function to use StringRef.  Requires converting
+    // GetCommandObjectForCommand.
     const std::string alias_command = args.GetArgumentAtIndex(0);
     if (alias_command.size() > 1 && alias_command[0] == '-') {
       result.AppendError("aliases starting with a dash are not supported");
@@ -719,6 +718,9 @@ protected:
       return false;
     }
 
+    // TODO: Convert these to StringRefs.  Should convert other dependent
+    // functions (CommandExists, UserCommandExists, AliasExists, AddAlias,
+    // etc at the same time.
     const std::string alias_command = args.GetArgumentAtIndex(0);
     const std::string actual_command = args.GetArgumentAtIndex(1);
 
@@ -744,11 +746,11 @@ protected:
         OptionArgVectorSP option_arg_vector_sp =
             OptionArgVectorSP(new OptionArgVector);
 
-        while (cmd_obj->IsMultiwordObject() && args.GetArgumentCount() > 0) {
+        while (cmd_obj->IsMultiwordObject() && !args.empty()) {
           if (argc >= 3) {
-            const std::string sub_command = args.GetArgumentAtIndex(0);
-            assert(sub_command.length() != 0);
-            subcommand_obj_sp = cmd_obj->GetSubcommandSP(sub_command.c_str());
+            llvm::StringRef sub_command = args.GetArgumentAtIndex(0);
+            assert(!sub_command.empty());
+            subcommand_obj_sp = cmd_obj->GetSubcommandSP(sub_command.data());
             if (subcommand_obj_sp) {
               sub_cmd_obj = subcommand_obj_sp.get();
               use_subcommand = true;
@@ -759,7 +761,7 @@ protected:
               result.AppendErrorWithFormat(
                   "'%s' is not a valid sub-command of '%s'.  "
                   "Unable to create alias.\n",
-                  sub_command.c_str(), actual_command.c_str());
+                  sub_command.data(), actual_command.c_str());
               result.SetStatus(eReturnStatusFailed);
               return false;
             }
@@ -770,7 +772,7 @@ protected:
 
         std::string args_string;
 
-        if (args.GetArgumentCount() > 0) {
+        if (!args.empty()) {
           CommandObjectSP tmp_sp =
               m_interpreter.GetCommandSPExact(cmd_obj->GetCommandName(), false);
           if (use_subcommand)
@@ -847,44 +849,48 @@ protected:
     CommandObject::CommandMap::iterator pos;
     CommandObject *cmd_obj;
 
-    if (args.GetArgumentCount() != 0) {
-      const char *command_name = args.GetArgumentAtIndex(0);
-      cmd_obj = m_interpreter.GetCommandObject(command_name);
-      if (cmd_obj) {
-        if (m_interpreter.CommandExists(command_name)) {
-          if (cmd_obj->IsRemovable()) {
-            result.AppendErrorWithFormat(
-                "'%s' is not an alias, it is a debugger command which can be "
-                "removed using the 'command delete' command.\n",
-                command_name);
-          } else {
-            result.AppendErrorWithFormat(
-                "'%s' is a permanent debugger command and cannot be removed.\n",
-                command_name);
-          }
-          result.SetStatus(eReturnStatusFailed);
+    if (args.empty()) {
+      result.AppendError("must call 'unalias' with a valid alias");
+      result.SetStatus(eReturnStatusFailed);
+      return false;
+    }
+
+    // TODO: Convert this function to return a StringRef.  Should also convert
+    // dependent functions GetCommandObject, CommandExists, RemoveAlias,
+    // AliasExists, etc.
+    const char *command_name = args.GetArgumentAtIndex(0);
+    cmd_obj = m_interpreter.GetCommandObject(command_name);
+    if (cmd_obj) {
+      if (m_interpreter.CommandExists(command_name)) {
+        if (cmd_obj->IsRemovable()) {
+          result.AppendErrorWithFormat(
+              "'%s' is not an alias, it is a debugger command which can be "
+              "removed using the 'command delete' command.\n",
+              command_name);
         } else {
-          if (!m_interpreter.RemoveAlias(command_name)) {
-            if (m_interpreter.AliasExists(command_name))
-              result.AppendErrorWithFormat(
-                  "Error occurred while attempting to unalias '%s'.\n",
-                  command_name);
-            else
-              result.AppendErrorWithFormat("'%s' is not an existing alias.\n",
-                                           command_name);
-            result.SetStatus(eReturnStatusFailed);
-          } else
-            result.SetStatus(eReturnStatusSuccessFinishNoResult);
+          result.AppendErrorWithFormat(
+              "'%s' is a permanent debugger command and cannot be removed.\n",
+              command_name);
         }
-      } else {
-        result.AppendErrorWithFormat(
-            "'%s' is not a known command.\nTry 'help' to see a "
-            "current list of commands.\n",
-            command_name);
         result.SetStatus(eReturnStatusFailed);
+      } else {
+        if (!m_interpreter.RemoveAlias(command_name)) {
+          if (m_interpreter.AliasExists(command_name))
+            result.AppendErrorWithFormat(
+                "Error occurred while attempting to unalias '%s'.\n",
+                command_name);
+          else
+            result.AppendErrorWithFormat("'%s' is not an existing alias.\n",
+                                         command_name);
+          result.SetStatus(eReturnStatusFailed);
+        } else
+          result.SetStatus(eReturnStatusSuccessFinishNoResult);
       }
     } else {
-      result.AppendError("must call 'unalias' with a valid alias");
+      result.AppendErrorWithFormat(
+          "'%s' is not a known command.\nTry 'help' to see a "
+          "current list of commands.\n",
+          command_name);
       result.SetStatus(eReturnStatusFailed);
     }
 
@@ -925,31 +931,32 @@ protected:
   bool DoExecute(Args &args, CommandReturnObject &result) override {
     CommandObject::CommandMap::iterator pos;
 
-    if (args.GetArgumentCount() != 0) {
-      const char *command_name = args.GetArgumentAtIndex(0);
-      if (m_interpreter.CommandExists(command_name)) {
-        if (m_interpreter.RemoveCommand(command_name)) {
-          result.SetStatus(eReturnStatusSuccessFinishNoResult);
-        } else {
-          result.AppendErrorWithFormat(
-              "'%s' is a permanent debugger command and cannot be removed.\n",
-              command_name);
-          result.SetStatus(eReturnStatusFailed);
-        }
+    if (args.empty()) {
+      result.AppendErrorWithFormat("must call '%s' with one or more valid user "
+                                   "defined regular expression command names",
+                                   GetCommandName());
+      result.SetStatus(eReturnStatusFailed);
+    }
+
+    // TODO: Convert this to accept a stringRef.
+    const char *command_name = args.GetArgumentAtIndex(0);
+    if (m_interpreter.CommandExists(command_name)) {
+      if (m_interpreter.RemoveCommand(command_name)) {
+        result.SetStatus(eReturnStatusSuccessFinishNoResult);
       } else {
-        StreamString error_msg_stream;
-        const bool generate_apropos = true;
-        const bool generate_type_lookup = false;
-        CommandObjectHelp::GenerateAdditionalHelpAvenuesMessage(
-            &error_msg_stream, command_name, nullptr, nullptr, generate_apropos,
-            generate_type_lookup);
-        result.AppendErrorWithFormat("%s", error_msg_stream.GetData());
+        result.AppendErrorWithFormat(
+            "'%s' is a permanent debugger command and cannot be removed.\n",
+            command_name);
         result.SetStatus(eReturnStatusFailed);
       }
     } else {
-      result.AppendErrorWithFormat("must call '%s' with one or more valid user "
-                                   "defined regular expression command names",
-                                   GetCommandName());
+      StreamString error_msg_stream;
+      const bool generate_apropos = true;
+      const bool generate_type_lookup = false;
+      CommandObjectHelp::GenerateAdditionalHelpAvenuesMessage(
+          &error_msg_stream, command_name, nullptr, nullptr, generate_apropos,
+          generate_type_lookup);
+      result.AppendErrorWithFormat("%s", error_msg_stream.GetData());
       result.SetStatus(eReturnStatusFailed);
     }
 
@@ -1064,48 +1071,49 @@ protected:
       result.AppendError("usage: 'command regex <command-name> "
                          "[s/<regex1>/<subst1>/ s/<regex2>/<subst2>/ ...]'\n");
       result.SetStatus(eReturnStatusFailed);
-    } else {
-      Error error;
-      const char *name = command.GetArgumentAtIndex(0);
-      m_regex_cmd_ap.reset(new CommandObjectRegexCommand(
-          m_interpreter, name, m_options.GetHelp(), m_options.GetSyntax(), 10,
-          0, true));
-
-      if (argc == 1) {
-        Debugger &debugger = m_interpreter.GetDebugger();
-        bool color_prompt = debugger.GetUseColor();
-        const bool multiple_lines = true; // Get multiple lines
-        IOHandlerSP io_handler_sp(new IOHandlerEditline(
-            debugger, IOHandler::Type::Other,
-            "lldb-regex",          // Name of input reader for history
-            llvm::StringRef("> "), // Prompt
-            llvm::StringRef(),     // Continuation prompt
-            multiple_lines, color_prompt,
-            0, // Don't show line numbers
-            *this));
-
-        if (io_handler_sp) {
-          debugger.PushIOHandler(io_handler_sp);
-          result.SetStatus(eReturnStatusSuccessFinishNoResult);
-        }
-      } else {
-        for (size_t arg_idx = 1; arg_idx < argc; ++arg_idx) {
-          llvm::StringRef arg_strref(command.GetArgumentAtIndex(arg_idx));
-          bool check_only = false;
-          error = AppendRegexSubstitution(arg_strref, check_only);
-          if (error.Fail())
-            break;
-        }
+      return false;
+    }
 
-        if (error.Success()) {
-          AddRegexCommandToInterpreter();
-        }
+    Error error;
+    const char *name = command.GetArgumentAtIndex(0);
+    m_regex_cmd_ap.reset(
+        new CommandObjectRegexCommand(m_interpreter, name, m_options.GetHelp(),
+                                      m_options.GetSyntax(), 10, 0, true));
+
+    if (argc == 1) {
+      Debugger &debugger = m_interpreter.GetDebugger();
+      bool color_prompt = debugger.GetUseColor();
+      const bool multiple_lines = true; // Get multiple lines
+      IOHandlerSP io_handler_sp(new IOHandlerEditline(
+          debugger, IOHandler::Type::Other,
+          "lldb-regex",          // Name of input reader for history
+          llvm::StringRef("> "), // Prompt
+          llvm::StringRef(),     // Continuation prompt
+          multiple_lines, color_prompt,
+          0, // Don't show line numbers
+          *this));
+
+      if (io_handler_sp) {
+        debugger.PushIOHandler(io_handler_sp);
+        result.SetStatus(eReturnStatusSuccessFinishNoResult);
       }
-      if (error.Fail()) {
-        result.AppendError(error.AsCString());
-        result.SetStatus(eReturnStatusFailed);
+    } else {
+      for (size_t arg_idx = 1; arg_idx < argc; ++arg_idx) {
+        llvm::StringRef arg_strref(command.GetArgumentAtIndex(arg_idx));
+        bool check_only = false;
+        error = AppendRegexSubstitution(arg_strref, check_only);
+        if (error.Fail())
+          break;
+      }
+
+      if (error.Success()) {
+        AddRegexCommandToInterpreter();
       }
     }
+    if (error.Fail()) {
+      result.AppendError(error.AsCString());
+      result.SetStatus(eReturnStatusFailed);
+    }
 
     return result.Succeeded();
   }
@@ -1254,6 +1262,7 @@ private:
       return llvm::makeArrayRef(g_regex_options);
     }
 
+    // TODO: Convert these functions to return StringRefs.
     const char *GetHelp() {
       return (m_help.empty() ? nullptr : m_help.c_str());
     }
@@ -1532,33 +1541,26 @@ protected:
       return false;
     }
 
-    size_t argc = command.GetArgumentCount();
-    if (0 == argc) {
+    if (command.empty()) {
       result.AppendError("command script import needs one or more arguments");
       result.SetStatus(eReturnStatusFailed);
       return false;
     }
 
-    for (size_t i = 0; i < argc; i++) {
-      std::string path = command.GetArgumentAtIndex(i);
+    for (auto &entry : command.entries()) {
       Error error;
 
       const bool init_session = true;
       // FIXME: this is necessary because CommandObject::CheckRequirements()
-      // assumes that
-      // commands won't ever be recursively invoked, but it's actually possible
-      // to craft
-      // a Python script that does other "command script imports" in
-      // __lldb_init_module
-      // the real fix is to have recursive commands possible with a
-      // CommandInvocation object
-      // separate from the CommandObject itself, so that recursive command
-      // invocations
-      // won't stomp on each other (wrt to execution contents, options, and
-      // more)
+      // assumes that commands won't ever be recursively invoked, but it's
+      // actually possible to craft a Python script that does other "command
+      // script imports" in __lldb_init_module the real fix is to have recursive
+      // commands possible with a CommandInvocation object separate from the
+      // CommandObject itself, so that recursive command invocations won't stomp
+      // on each other (wrt to execution contents, options, and more)
       m_exe_ctx.Clear();
       if (m_interpreter.GetScriptInterpreter()->LoadScriptingModule(
-              path.c_str(), m_options.m_allow_reload, init_session, error)) {
+              entry.c_str(), m_options.m_allow_reload, init_session, error)) {
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
       } else {
         result.AppendErrorWithFormat("module importing failed: %s",
@@ -1752,9 +1754,7 @@ protected:
       return false;
     }
 
-    size_t argc = command.GetArgumentCount();
-
-    if (argc != 1) {
+    if (command.GetArgumentCount() != 1) {
       result.AppendError("'command script add' requires one argument");
       result.SetStatus(eReturnStatusFailed);
       return false;
@@ -1892,9 +1892,7 @@ public:
 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
 
-    size_t argc = command.GetArgumentCount();
-
-    if (argc != 1) {
+    if (command.GetArgumentCount() != 1) {
       result.AppendError("'command script delete' requires one argument");
       result.SetStatus(eReturnStatusFailed);
       return false;
diff --git a/lldb/source/Commands/CommandObjectDisassemble.cpp b/lldb/source/Commands/CommandObjectDisassemble.cpp
index 93fda555b10..079503341bc 100644
--- a/lldb/source/Commands/CommandObjectDisassemble.cpp
+++ b/lldb/source/Commands/CommandObjectDisassemble.cpp
@@ -300,7 +300,7 @@ bool CommandObjectDisassemble::DoExecute(Args &command,
 
   result.SetStatus(eReturnStatusSuccessFinishResult);
 
-  if (command.GetArgumentCount() != 0) {
+  if (!command.empty()) {
     result.AppendErrorWithFormat(
         "\"disassemble\" arguments are specified as options.\n");
     const int terminal_width =
diff --git a/lldb/source/Commands/CommandObjectFrame.cpp b/lldb/source/Commands/CommandObjectFrame.cpp
index 8688f038698..3c7b7d9d7f1 100644
--- a/lldb/source/Commands/CommandObjectFrame.cpp
+++ b/lldb/source/Commands/CommandObjectFrame.cpp
@@ -533,7 +533,7 @@ protected:
       const Format format = m_option_format.GetFormat();
       options.SetFormat(format);
 
-      if (command.GetArgumentCount() > 0) {
+      if (!command.empty()) {
         VariableList regex_var_list;
 
         // If we have any args to the variable command, we will make
diff --git a/lldb/source/Commands/CommandObjectLog.cpp b/lldb/source/Commands/CommandObjectLog.cpp
index 350f8d03794..34dc7106231 100644
--- a/lldb/source/Commands/CommandObjectLog.cpp
+++ b/lldb/source/Commands/CommandObjectLog.cpp
@@ -182,22 +182,24 @@ protected:
       result.AppendErrorWithFormat(
           "%s takes a log channel and one or more log types.\n",
           m_cmd_name.c_str());
-    } else {
-      std::string channel(args.GetArgumentAtIndex(0));
-      args.Shift(); // Shift off the channel
-      char log_file[PATH_MAX];
-      if (m_options.log_file)
-        m_options.log_file.GetPath(log_file, sizeof(log_file));
-      else
-        log_file[0] = '\0';
-      bool success = m_interpreter.GetDebugger().EnableLog(
-          channel.c_str(), args.GetConstArgumentVector(), log_file,
-          m_options.log_options, result.GetErrorStream());
-      if (success)
-        result.SetStatus(eReturnStatusSuccessFinishNoResult);
-      else
-        result.SetStatus(eReturnStatusFailed);
+      return false;
     }
+
+    // Store into a std::string since we're about to shift the channel off.
+    std::string channel = args.GetArgumentAtIndex(0);
+    args.Shift(); // Shift off the channel
+    char log_file[PATH_MAX];
+    if (m_options.log_file)
+      m_options.log_file.GetPath(log_file, sizeof(log_file));
+    else
+      log_file[0] = '\0';
+    bool success = m_interpreter.GetDebugger().EnableLog(
+        channel.c_str(), args.GetConstArgumentVector(), log_file,
+        m_options.log_options, result.GetErrorStream());
+    if (success)
+      result.SetStatus(eReturnStatusSuccessFinishNoResult);
+    else
+      result.SetStatus(eReturnStatusFailed);
     return result.Succeeded();
   }
 
@@ -240,33 +242,32 @@ public:
 
 protected:
   bool DoExecute(Args &args, CommandReturnObject &result) override {
-    const size_t argc = args.GetArgumentCount();
-    if (argc == 0) {
+    if (args.empty()) {
       result.AppendErrorWithFormat(
           "%s takes a log channel and one or more log types.\n",
           m_cmd_name.c_str());
+      return false;
+    }
+
+    Log::Callbacks log_callbacks;
+
+    const std::string channel = args.GetArgumentAtIndex(0);
+    args.Shift(); // Shift off the channel
+    if (Log::GetLogChannelCallbacks(ConstString(channel), log_callbacks)) {
+      log_callbacks.disable(args.GetConstArgumentVector(),
+                            &result.GetErrorStream());
+      result.SetStatus(eReturnStatusSuccessFinishNoResult);
+    } else if (channel == "all") {
+      Log::DisableAllLogChannels(&result.GetErrorStream());
     } else {
-      Log::Callbacks log_callbacks;
-
-      std::string channel(args.GetArgumentAtIndex(0));
-      args.Shift(); // Shift off the channel
-      if (Log::GetLogChannelCallbacks(ConstString(channel.c_str()),
-                                      log_callbacks)) {
-        log_callbacks.disable(args.GetConstArgumentVector(),
-                              &result.GetErrorStream());
+      LogChannelSP log_channel_sp(LogChannel::FindPlugin(channel.data()));
+      if (log_channel_sp) {
+        log_channel_sp->Disable(args.GetConstArgumentVector(),
+                                &result.GetErrorStream());
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
-      } else if (channel == "all") {
-        Log::DisableAllLogChannels(&result.GetErrorStream());
-      } else {
-        LogChannelSP log_channel_sp(LogChannel::FindPlugin(channel.c_str()));
-        if (log_channel_sp) {
-          log_channel_sp->Disable(args.GetConstArgumentVector(),
-                                  &result.GetErrorStream());
-          result.SetStatus(eReturnStatusSuccessFinishNoResult);
-        } else
-          result.AppendErrorWithFormat("Invalid log channel '%s'.\n",
-                                       args.GetArgumentAtIndex(0));
-      }
+      } else
+        result.AppendErrorWithFormat("Invalid log channel '%s'.\n",
+                                     channel.data());
     }
     return result.Succeeded();
   }
@@ -301,30 +302,28 @@ public:
 
 protected:
   bool DoExecute(Args &args, CommandReturnObject &result) override {
-    const size_t argc = args.GetArgumentCount();
-    if (argc == 0) {
+    if (args.empty()) {
       Log::ListAllLogChannels(&result.GetOutputStream());
       result.SetStatus(eReturnStatusSuccessFinishResult);
     } else {
-      for (size_t i = 0; i < argc; ++i) {
+      for (auto &entry : args.entries()) {
         Log::Callbacks log_callbacks;
 
-        std::string channel(args.GetArgumentAtIndex(i));
-        if (Log::GetLogChannelCallbacks(ConstString(channel.c_str()),
+        if (Log::GetLogChannelCallbacks(ConstString(entry.ref),
                                         log_callbacks)) {
           log_callbacks.list_categories(&result.GetOutputStream());
           result.SetStatus(eReturnStatusSuccessFinishResult);
-        } else if (channel == "all") {
+        } else if (entry.ref == "all") {
           Log::ListAllLogChannels(&result.GetOutputStream());
           result.SetStatus(eReturnStatusSuccessFinishResult);
         } else {
-          LogChannelSP log_channel_sp(LogChannel::FindPlugin(channel.c_str()));
+          LogChannelSP log_channel_sp(LogChannel::FindPlugin(entry.c_str()));
           if (log_channel_sp) {
             log_channel_sp->ListCategories(&result.GetOutputStream());
             result.SetStatus(eReturnStatusSuccessFinishNoResult);
           } else
             result.AppendErrorWithFormat("Invalid log channel '%s'.\n",
-                                         args.GetArgumentAtIndex(0));
+                                         entry.c_str());
         }
       }
     }
@@ -348,45 +347,41 @@ public:
 
 protected:
   bool DoExecute(Args &args, CommandReturnObject &result) override {
-    const size_t argc = args.GetArgumentCount();
     result.SetStatus(eReturnStatusFailed);
 
-    if (argc == 1) {
-      const char *sub_command = args.GetArgumentAtIndex(0);
+    if (args.GetArgumentCount() == 1) {
+      llvm::StringRef sub_command = args.GetArgumentAtIndex(0);
 
-      if (strcasecmp(sub_command, "enable") == 0) {
+      if (sub_command.equals_lower("enable")) {
         Timer::SetDisplayDepth(UINT32_MAX);
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
-      } else if (strcasecmp(sub_command, "disable") == 0) {
+      } else if (sub_command.equals_lower("disable")) {
         Timer::DumpCategoryTimes(&result.GetOutputStream());
         Timer::SetDisplayDepth(0);
         result.SetStatus(eReturnStatusSuccessFinishResult);
-      } else if (strcasecmp(sub_command, "dump") == 0) {
+      } else if (sub_command.equals_lower("dump")) {
         Timer::DumpCategoryTimes(&result.GetOutputStream());
         result.SetStatus(eReturnStatusSuccessFinishResult);
-      } else if (strcasecmp(sub_command, "reset") == 0) {
+      } else if (sub_command.equals_lower("reset")) {
         Timer::ResetCategoryTimes();
         result.SetStatus(eReturnStatusSuccessFinishResult);
       }
-    } else if (argc == 2) {
-      const char *sub_command = args.GetArgumentAtIndex(0);
+    } else if (args.GetArgumentCount() == 2) {
+      llvm::StringRef sub_command = args.GetArgumentAtIndex(0);
+      llvm::StringRef param = args.GetArgumentAtIndex(1);
 
-      if (strcasecmp(sub_command, "enable") == 0) {
-        bool success;
-        uint32_t depth =
-            StringConvert::ToUInt32(args.GetArgumentAtIndex(1), 0, 0, &success);
-        if (success) {
-          Timer::SetDisplayDepth(depth);
-          result.SetStatus(eReturnStatusSuccessFinishNoResult);
-        } else
+      if (sub_command.equals_lower("enable")) {
+        uint32_t depth;
+        if (param.consumeInteger(0, depth)) {
           result.AppendError(
               "Could not convert enable depth to an unsigned integer.");
-      }
-      if (strcasecmp(sub_command, "increment") == 0) {
+        } else {
+          Timer::SetDisplayDepth(depth);
+          result.SetStatus(eReturnStatusSuccessFinishNoResult);
+        }
+      } else if (sub_command.equals_lower("increment")) {
         bool success;
-        bool increment = Args::StringToBoolean(
-            llvm::StringRef::withNullAsEmpty(args.GetArgumentAtIndex(1)), false,
-            &success);
+        bool increment = Args::StringToBoolean(param, false, &success);
         if (success) {
           Timer::SetQuiet(!increment);
           result.SetStatus(eReturnStatusSuccessFinishNoResult);