Simplify WindowsCommandLineArguments, and move to example code.

Eliminates one use of strcpyn.

Bug: None
Change-Id: I339a41d3d978f584fbb00ebfbffa31e4133ae33f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/135741
Commit-Queue: Niels Moller <[email protected]>
Reviewed-by: Karl Wiberg <[email protected]>
Cr-Commit-Position: refs/heads/master@{#27910}

Author: Niels Möller

examples/peerconnection/client/main.cc

@@ -8,17 +8,68 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+// clang-format off
+// clang formating would change include order.
+#include <windows.h>
+#include <shellapi.h>  // must come after windows.h
+// clang-format on
+
+#include <string>
+#include <vector>
+
 #include "examples/peerconnection/client/conductor.h"
 #include "examples/peerconnection/client/flag_defs.h"
 #include "examples/peerconnection/client/main_wnd.h"
 #include "examples/peerconnection/client/peer_connection_client.h"
 #include "rtc_base/checks.h"
+#include "rtc_base/constructor_magic.h"
 #include "rtc_base/ssl_adapter.h"
+#include "rtc_base/string_utils.h"  // For ToUtf8
 #include "rtc_base/win32_socket_init.h"
 #include "rtc_base/win32_socket_server.h"
 #include "system_wrappers/include/field_trial.h"
 #include "test/field_trial.h"
 
+namespace {
+// A helper class to translate Windows command line arguments into UTF8,
+// which then allows us to just pass them to the flags system.
+// This encapsulates all the work of getting the command line and translating
+// it to an array of 8-bit strings; all you have to do is create one of these,
+// and then call argc() and argv().
+class WindowsCommandLineArguments {
+ public:
+  WindowsCommandLineArguments();
+
+  int argc() { return argv_.size(); }
+  const char** argv() { return argv_.data(); }
+
+ private:
+  // Owned argument strings.
+  std::vector<std::string> args_;
+  // Pointers, to get layout compatible with char** argv.
+  std::vector<const char*> argv_;
+
+ private:
+  RTC_DISALLOW_COPY_AND_ASSIGN(WindowsCommandLineArguments);
+};
+
+WindowsCommandLineArguments::WindowsCommandLineArguments() {
+  // start by getting the command line.
+  LPCWSTR command_line = ::GetCommandLineW();
+  // now, convert it to a list of wide char strings.
+  int argc;
+  LPWSTR* wide_argv = ::CommandLineToArgvW(command_line, &argc);
+
+  // iterate over the returned wide strings;
+  for (int i = 0; i < argc; ++i) {
+    args_.push_back(rtc::ToUtf8(wide_argv[i], wcslen(wide_argv[i])));
+    // make sure the argv array points to the string data.
+    argv_.push_back(args_.back().c_str());
+  }
+  LocalFree(wide_argv);
+}
+
+}  // namespace
 int PASCAL wWinMain(HINSTANCE instance,
                     HINSTANCE prev_instance,
                     wchar_t* cmd_line,
@@ -28,9 +79,9 @@ int PASCAL wWinMain(HINSTANCE instance,
   rtc::Win32Thread w32_thread(&w32_ss);
   rtc::ThreadManager::Instance()->SetCurrentThread(&w32_thread);
 
-  rtc::WindowsCommandLineArguments win_args;
+  WindowsCommandLineArguments win_args;
   int argc = win_args.argc();
-  char** argv = win_args.argv();
+  const char** argv = win_args.argv();
 
   rtc::FlagList::SetFlagsFromCommandLine(&argc, argv, true);
   if (FLAG_help) {

rtc_base/flags.cc

@@ -16,16 +16,6 @@
 
 #include "rtc_base/checks.h"
 
-#if defined(WEBRTC_WIN)
-// clang-format off
-// clang formating would change include order.
-#include <windows.h>
-#include <shellapi.h> // must come after windows.h
-// clang-format on
-
-#include "rtc_base/string_utils.h"  // For ToUtf8
-#endif
-
 namespace {
 bool FlagEq(const char* arg, const char* flag) {
   // Compare two flags for equality.
@@ -289,35 +279,4 @@ void FlagList::Register(Flag* flag) {
   list_ = flag;
 }
 
-#if defined(WEBRTC_WIN)
-WindowsCommandLineArguments::WindowsCommandLineArguments() {
-  // start by getting the command line.
-  LPCWSTR command_line = ::GetCommandLineW();
-  // now, convert it to a list of wide char strings.
-  LPWSTR* wide_argv = ::CommandLineToArgvW(command_line, &argc_);
-  // now allocate an array big enough to hold that many string pointers.
-  argv_ = new char*[argc_];
-
-  // iterate over the returned wide strings;
-  for (int i = 0; i < argc_; ++i) {
-    std::string s = rtc::ToUtf8(wide_argv[i], wcslen(wide_argv[i]));
-    char* buffer = new char[s.length() + 1];
-    rtc::strcpyn(buffer, s.length() + 1, s.c_str());
-
-    // make sure the argv array has the right string at this point.
-    argv_[i] = buffer;
-  }
-  LocalFree(wide_argv);
-}
-
-WindowsCommandLineArguments::~WindowsCommandLineArguments() {
-  // need to free each string in the array, and then the array.
-  for (int i = 0; i < argc_; i++) {
-    delete[] argv_[i];
-  }
-
-  delete[] argv_;
-}
-#endif  // WEBRTC_WIN
-
 }  // namespace rtc

rtc_base/flags.h

@@ -24,10 +24,6 @@
 
 #include "rtc_base/checks.h"
 
-#if defined(WEBRTC_WIN)
-#include "rtc_base/constructor_magic.h"
-#endif
-
 namespace rtc {
 
 // Internal use only.
@@ -243,29 +239,6 @@ class FlagList {
   static Flag* list_;
 };
 
-#if defined(WEBRTC_WIN)
-// A helper class to translate Windows command line arguments into UTF8,
-// which then allows us to just pass them to the flags system.
-// This encapsulates all the work of getting the command line and translating
-// it to an array of 8-bit strings; all you have to do is create one of these,
-// and then call argc() and argv().
-class WindowsCommandLineArguments {
- public:
-  WindowsCommandLineArguments();
-  ~WindowsCommandLineArguments();
-
-  int argc() { return argc_; }
-  char** argv() { return argv_; }
-
- private:
-  int argc_;
-  char** argv_;
-
- private:
-  RTC_DISALLOW_COPY_AND_ASSIGN(WindowsCommandLineArguments);
-};
-#endif  // WEBRTC_WIN
-
 }  // namespace rtc
 
 #endif  // SHARED_COMMANDLINEFLAGS_FLAGS_H_