base: Support command line wrappers with quoted arguments

base/command_line.cc

Index: base/command_line.cc
diff --git a/base/command_line.cc b/base/command_line.cc
index 99ea2b000324b87ea4ab11bae1f7c5374586331c..e632d35b76fce4832927cdcad2d0da2de6cb3ba4 100644
--- a/base/command_line.cc
+++ b/base/command_line.cc
@@ -11,6 +11,7 @@
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/strings/string_split.h"
+#include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
@@ -411,14 +412,15 @@ void CommandLine::AppendArguments(const CommandLine& other,
 void CommandLine::PrependWrapper(const CommandLine::StringType& wrapper) {
   if (wrapper.empty())
     return;
-  // The wrapper may have embedded arguments (like "gdb --args"). In this case,
-  // we don't pretend to do anything fancy, we just split on spaces.
-  StringVector wrapper_argv = SplitString(
-      wrapper, FilePath::StringType(1, ' '), base::TRIM_WHITESPACE,
-      base::SPLIT_WANT_ALL);
-  // Prepend the wrapper and update the switches/arguments |begin_args_|.
-  argv_.insert(argv_.begin(), wrapper_argv.begin(), wrapper_argv.end());
-  begin_args_ += wrapper_argv.size();
+  // Split the wrapper command based on whitespace (with quoting).
+  StringTokenizer tokenizer(wrapper, " ");

[gab, 2017/03/28 17:03:59]

This won't compile on Windows I think (CommandLine::StringType will be string16)

using CommandLineTokenizer = StringTokenizerT<CommandLine::StringType,
CommandLine::StringType::const_iterator>;

will probably work?

[Sami, 2017/03/28 17:54:09]

Ah, thanks for the tip! Done.

+  tokenizer.set_quote_chars("'\"");
+  // Prepend the wrapper and update the switches/arguments |begin_args_|
+  auto it = argv_.begin();
+  while (tokenizer.GetNext()) {
+    it = argv_.emplace(it, tokenizer.token()) + 1;

[gab, 2017/03/28 17:03:59]

Pushing in front of vector repeatedly is inefficient, build outside of loop and
insert in one pass like SplitString() approach effectively used to do?

[Sami, 2017/03/28 17:54:09]

Right you are -- done.

+    begin_args_++;

[gab, 2017/03/28 17:04:00]

Irrelevant after above comment but FWIW: prefer pre-increment when it's
equivalent

[Sami, 2017/03/28 17:54:09]

Acknowledged.

+  }
 }
 
 #if defined(OS_WIN)