Fix more functions in Args to use StringRef.

This patch also marks the const char* versions as =delete to prevent
their use.  This has the potential to cause build breakages on some
platforms which I can't compile.  I have tested on Windows, Linux,
and OSX.  Best practices for fixing broken callsites are outlined in
Args.h in a comment above the deleted function declarations.

Eventually we can remove these =delete declarations, but for now they
are important to make sure that all implicit conversions from
const char * are manually audited to make sure that they do not invoke a
conversion from nullptr.

llvm-svn: 281919

7 files changed, 41 insertions, 53 deletions

diff --git a/lldb/source/Interpreter/Args.cpp b/lldb/source/Interpreter/Args.cpp
index b6a60263e8f..0dd093fe27a 100644
--- a/lldb/source/Interpreter/Args.cpp
+++ b/lldb/source/Interpreter/Args.cpp
@@ -362,23 +362,23 @@ const char *Args::Unshift(const char *arg_cstr, char quote_char) {
 void Args::AppendArguments(const Args &rhs) {
   const size_t rhs_argc = rhs.GetArgumentCount();
   for (size_t i = 0; i < rhs_argc; ++i)
-    AppendArgument(rhs.GetArgumentAtIndex(i),
+    AppendArgument(llvm::StringRef(rhs.GetArgumentAtIndex(i)),
                    rhs.GetArgumentQuoteCharAtIndex(i));
 }
 
 void Args::AppendArguments(const char **argv) {
   if (argv) {
     for (uint32_t i = 0; argv[i]; ++i)
-      AppendArgument(argv[i]);
+      AppendArgument(llvm::StringRef::withNullAsEmpty(argv[i]));
   }
 }
 
-const char *Args::AppendArgument(const char *arg_cstr, char quote_char) {
-  return InsertArgumentAtIndex(GetArgumentCount(), arg_cstr, quote_char);
+llvm::StringRef Args::AppendArgument(llvm::StringRef arg_str, char quote_char) {
+  return InsertArgumentAtIndex(GetArgumentCount(), arg_str, quote_char);
 }
 
-const char *Args::InsertArgumentAtIndex(size_t idx, const char *arg_cstr,
-                                        char quote_char) {
+llvm::StringRef Args::InsertArgumentAtIndex(size_t idx, llvm::StringRef arg_str,
+                                            char quote_char) {
   // Since we are using a std::list to hold onto the copied C string and
   // we don't have direct access to the elements, we have to iterate to
   // find the value.
@@ -387,7 +387,7 @@ const char *Args::InsertArgumentAtIndex(size_t idx, const char *arg_cstr,
   for (pos = m_args.begin(); i > 0 && pos != end; ++pos)
     --i;
 
-  pos = m_args.insert(pos, arg_cstr);
+  pos = m_args.insert(pos, arg_str);
 
   if (idx >= m_args_quote_char.size()) {
     m_args_quote_char.resize(idx + 1);
@@ -399,8 +399,9 @@ const char *Args::InsertArgumentAtIndex(size_t idx, const char *arg_cstr,
   return GetArgumentAtIndex(idx);
 }
 
-const char *Args::ReplaceArgumentAtIndex(size_t idx, const char *arg_cstr,
-                                         char quote_char) {
+llvm::StringRef Args::ReplaceArgumentAtIndex(size_t idx,
+                                             llvm::StringRef arg_str,
+                                             char quote_char) {
   // Since we are using a std::list to hold onto the copied C string and
   // we don't have direct access to the elements, we have to iterate to
   // find the value.
@@ -410,7 +411,7 @@ const char *Args::ReplaceArgumentAtIndex(size_t idx, const char *arg_cstr,
     --i;
 
   if (pos != end) {
-    pos->assign(arg_cstr);
+    pos->assign(arg_str);
     assert(idx < m_argv.size() - 1);
     m_argv[idx] = pos->c_str();
     if (idx >= m_args_quote_char.size())
@@ -732,11 +733,6 @@ const char *Args::StripSpaces(std::string &s, bool leading, bool trailing,
   return s.c_str();
 }
 
-bool Args::StringToBoolean(const char *s, bool fail_value,
-  bool *success_ptr) {
-  return StringToBoolean(llvm::StringRef(s ? s : ""), fail_value, success_ptr);
-}
-
 bool Args::StringToBoolean(llvm::StringRef ref, bool fail_value,
                            bool *success_ptr) {
   if (success_ptr)
@@ -915,13 +911,6 @@ Error Args::StringToFormat(const char *s, lldb::Format &format,
   return error;
 }
 
-lldb::Encoding Args::StringToEncoding(const char *s,
-                                      lldb::Encoding fail_value) {
-  if (!s)
-    return fail_value;
-  return StringToEncoding(llvm::StringRef(s), fail_value);
-}
-
 lldb::Encoding Args::StringToEncoding(llvm::StringRef s,
                                       lldb::Encoding fail_value) {
   return llvm::StringSwitch<lldb::Encoding>(s)
@@ -932,12 +921,6 @@ lldb::Encoding Args::StringToEncoding(llvm::StringRef s,
       .Default(fail_value);
 }
 
-uint32_t Args::StringToGenericRegister(const char *s) {
-  if (!s)
-    return LLDB_INVALID_REGNUM;
-  return StringToGenericRegister(llvm::StringRef(s));
-}
-
 uint32_t Args::StringToGenericRegister(llvm::StringRef s) {
   if (s.empty())
     return LLDB_INVALID_REGNUM;
@@ -1015,13 +998,13 @@ void Args::AddOrReplaceEnvironmentVariable(const char *env_var_name,
 
     // Check if the name matches the given env_var_name.
     if (strncmp(env_var_name, arg_value, equal_p - arg_value) == 0) {
-      ReplaceArgumentAtIndex(i, stream.GetString().c_str());
+      ReplaceArgumentAtIndex(i, stream.GetString());
       return;
     }
   }
 
   // We didn't find it.  Append it instead.
-  AppendArgument(stream.GetString().c_str());
+  AppendArgument(stream.GetString());
 }
 
 bool Args::ContainsEnvironmentVariable(const char *env_var_name,
@@ -1239,7 +1222,7 @@ void Args::ParseAliasOptions(Options &options, CommandReturnObject &result,
           if (pos != std::string::npos)
             raw_input_string.erase(pos, strlen(tmp_arg));
         }
-        ReplaceArgumentAtIndex(idx, "");
+        ReplaceArgumentAtIndex(idx, llvm::StringRef());
         if ((long_options[long_options_index].definition->option_has_arg !=
              OptionParser::eNoArgument) &&
             (OptionParser::GetOptionArgument() != nullptr) &&
@@ -1252,7 +1235,7 @@ void Args::ParseAliasOptions(Options &options, CommandReturnObject &result,
             if (pos != std::string::npos)
               raw_input_string.erase(pos, strlen(tmp_arg));
           }
-          ReplaceArgumentAtIndex(idx + 1, "");
+          ReplaceArgumentAtIndex(idx + 1, llvm::StringRef());
         }
       }
     }
diff --git a/lldb/source/Interpreter/CommandInterpreter.cpp b/lldb/source/Interpreter/CommandInterpreter.cpp
index 1bc5103793b..32bcca83522 100644
--- a/lldb/source/Interpreter/CommandInterpreter.cpp
+++ b/lldb/source/Interpreter/CommandInterpreter.cpp
@@ -1760,7 +1760,7 @@ int CommandInterpreter::HandleCompletionMatches(
         look_for_subcommand = true;
         num_command_matches = 0;
         matches.DeleteStringAtIndex(0);
-        parsed_line.AppendArgument("");
+        parsed_line.AppendArgument(llvm::StringRef());
         cursor_index++;
         cursor_char_position = 0;
       }
@@ -1842,7 +1842,8 @@ int CommandInterpreter::HandleCompletion(
         partial_parsed_line.GetArgumentAtIndex(cursor_index);
     if (cursor_char_position == 0 ||
         current_elem[cursor_char_position - 1] != ' ') {
-      parsed_line.InsertArgumentAtIndex(cursor_index + 1, "", '\0');
+      parsed_line.InsertArgumentAtIndex(cursor_index + 1, llvm::StringRef(),
+                                        '\0');
       cursor_index++;
       cursor_char_position = 0;
     }
@@ -1987,21 +1988,23 @@ void CommandInterpreter::BuildAliasCommandArgs(CommandObject *alias_cmd_obj,
                                                             // this above, make
                                                             // sure we don't
                                                             // insert it twice
-          new_args.AppendArgument(value.c_str());
+                                                            new_args
+                                                                .AppendArgument(
+                                                                    value);
       } else {
         if (value_type != OptionParser::eOptionalArgument)
-          new_args.AppendArgument(option.c_str());
+          new_args.AppendArgument(option);
         if (value.compare("<no-argument>") != 0) {
           int index = GetOptionArgumentPosition(value.c_str());
           if (index == 0) {
             // value was NOT a positional argument; must be a real value
             if (value_type != OptionParser::eOptionalArgument)
-              new_args.AppendArgument(value.c_str());
+              new_args.AppendArgument(value);
             else {
               char buffer[255];
               ::snprintf(buffer, sizeof(buffer), "%s%s", option.c_str(),
                          value.c_str());
-              new_args.AppendArgument(buffer);
+              new_args.AppendArgument(llvm::StringRef(buffer));
             }
 
           } else if (static_cast<size_t>(index) >=
@@ -2023,12 +2026,13 @@ void CommandInterpreter::BuildAliasCommandArgs(CommandObject *alias_cmd_obj,
             }
 
             if (value_type != OptionParser::eOptionalArgument)
-              new_args.AppendArgument(cmd_args.GetArgumentAtIndex(index));
+              new_args.AppendArgument(llvm::StringRef::withNullAsEmpty(
+                  cmd_args.GetArgumentAtIndex(index)));
             else {
               char buffer[255];
               ::snprintf(buffer, sizeof(buffer), "%s%s", option.c_str(),
                          cmd_args.GetArgumentAtIndex(index));
-              new_args.AppendArgument(buffer);
+              new_args.AppendArgument(llvm::StringRef(buffer));
             }
             used[index] = true;
           }
@@ -2038,7 +2042,8 @@ void CommandInterpreter::BuildAliasCommandArgs(CommandObject *alias_cmd_obj,
 
     for (size_t j = 0; j < cmd_args.GetArgumentCount(); ++j) {
       if (!used[j] && !wants_raw_input)
-        new_args.AppendArgument(cmd_args.GetArgumentAtIndex(j));
+        new_args.AppendArgument(
+            llvm::StringRef(cmd_args.GetArgumentAtIndex(j)));
     }
 
     cmd_args.Clear();
diff --git a/lldb/source/Interpreter/CommandObject.cpp b/lldb/source/Interpreter/CommandObject.cpp
index d42d3c7f111..702939a1110 100644
--- a/lldb/source/Interpreter/CommandObject.cpp
+++ b/lldb/source/Interpreter/CommandObject.cpp
@@ -300,10 +300,9 @@ int CommandObject::HandleCompletion(Args &input, int &cursor_index,
       cursor_index++;
 
       // I stick an element on the end of the input, because if the last element
-      // is
-      // option that requires an argument, getopt_long_only will freak out.
+      // is option that requires an argument, getopt_long_only will freak out.
 
-      input.AppendArgument("<FAKE-VALUE>");
+      input.AppendArgument(llvm::StringRef("<FAKE-VALUE>"));
 
       input.ParseArgsForCompletion(*cur_options, opt_element_vector,
                                    cursor_index);
@@ -1001,7 +1000,8 @@ bool CommandObjectParsed::Execute(const char *args_string,
       const char *tmp_str = cmd_args.GetArgumentAtIndex(i);
       if (tmp_str[0] == '`') // back-quote
         cmd_args.ReplaceArgumentAtIndex(
-            i, m_interpreter.ProcessEmbeddedScriptCommands(tmp_str));
+            i, llvm::StringRef::withNullAsEmpty(
+                   m_interpreter.ProcessEmbeddedScriptCommands(tmp_str)));
     }
 
     if (CheckRequirements(result)) {
diff --git a/lldb/source/Interpreter/OptionGroupValueObjectDisplay.cpp b/lldb/source/Interpreter/OptionGroupValueObjectDisplay.cpp
index 5ce7fb8ed72..e5943925e86 100644
--- a/lldb/source/Interpreter/OptionGroupValueObjectDisplay.cpp
+++ b/lldb/source/Interpreter/OptionGroupValueObjectDisplay.cpp
@@ -85,6 +85,8 @@ Error OptionGroupValueObjectDisplay::SetOptionValue(
   const int short_option = g_option_table[option_idx].short_option;
   bool success = false;
 
+  auto option_strref = llvm::StringRef::withNullAsEmpty(option_arg);
+
   switch (short_option) {
   case 'd': {
     int32_t result;
@@ -141,13 +143,13 @@ Error OptionGroupValueObjectDisplay::SetOptionValue(
     break;
 
   case 'S':
-    use_synth = Args::StringToBoolean(option_arg, true, &success);
+    use_synth = Args::StringToBoolean(option_strref, true, &success);
     if (!success)
       error.SetErrorStringWithFormat("invalid synthetic-type '%s'", option_arg);
     break;
 
   case 'V':
-    run_validator = Args::StringToBoolean(option_arg, true, &success);
+    run_validator = Args::StringToBoolean(option_strref, true, &success);
     if (!success)
       error.SetErrorStringWithFormat("invalid validate '%s'", option_arg);
     break;
diff --git a/lldb/source/Interpreter/OptionValueBoolean.cpp b/lldb/source/Interpreter/OptionValueBoolean.cpp
index dbbd46ea093..bd988fa5750 100644
--- a/lldb/source/Interpreter/OptionValueBoolean.cpp
+++ b/lldb/source/Interpreter/OptionValueBoolean.cpp
@@ -1,5 +1,4 @@
-//===-- OptionValueBoolean.cpp ------------------------------------*- C++
-//-*-===//
+//===-- OptionValueBoolean.cpp ----------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -48,8 +47,7 @@ Error OptionValueBoolean::SetValueFromString(llvm::StringRef value_str,
   case eVarSetOperationReplace:
   case eVarSetOperationAssign: {
     bool success = false;
-    bool value =
-        Args::StringToBoolean(value_str.str().c_str(), false, &success);
+    bool value = Args::StringToBoolean(value_str, false, &success);
     if (success) {
       m_value_was_set = true;
       m_current_value = value;
diff --git a/lldb/source/Interpreter/OptionValueDictionary.cpp b/lldb/source/Interpreter/OptionValueDictionary.cpp
index cf8715eebb1..da68a686045 100644
--- a/lldb/source/Interpreter/OptionValueDictionary.cpp
+++ b/lldb/source/Interpreter/OptionValueDictionary.cpp
@@ -85,7 +85,7 @@ size_t OptionValueDictionary::GetArgs(Args &args) const {
     StreamString strm;
     strm.Printf("%s=", pos->first.GetCString());
     pos->second->DumpValue(nullptr, strm, eDumpOptionValue | eDumpOptionRaw);
-    args.AppendArgument(strm.GetString().c_str());
+    args.AppendArgument(strm.GetString());
   }
   return args.GetArgumentCount();
 }
diff --git a/lldb/source/Interpreter/Property.cpp b/lldb/source/Interpreter/Property.cpp
index ba859a5398c..a15b985e8bb 100644
--- a/lldb/source/Interpreter/Property.cpp
+++ b/lldb/source/Interpreter/Property.cpp
@@ -54,7 +54,7 @@ Property::Property(const PropertyDefinition &definition)
     // default value.
     if (definition.default_cstr_value)
       m_value_sp.reset(new OptionValueBoolean(Args::StringToBoolean(
-          definition.default_cstr_value, false, nullptr)));
+          llvm::StringRef(definition.default_cstr_value), false, nullptr)));
     else
       m_value_sp.reset(
           new OptionValueBoolean(definition.default_uint_value != 0));