Add support to compile the gazebo executable on Windows

CMakeLists.txt

@@ -1,4 +1,8 @@
-cmake_minimum_required(VERSION 3.10.2 FATAL_ERROR)
+if(WIN32)
+  cmake_minimum_required(VERSION 3.11 FATAL_ERROR)
+else()
+  cmake_minimum_required(VERSION 3.10.2 FATAL_ERROR)
+endif()
 
 if(COMMAND CMAKE_POLICY)
   CMAKE_POLICY(SET CMP0003 NEW)

cmake/SearchForStuff.cmake

@@ -865,3 +865,18 @@ else()
   message (STATUS "Looking for qwt >= 6.1.0 - not found")
   BUILD_ERROR ("Missing: libqwt-dev. Required for plotting.")
 endif ()
+
+########################################
+# On Windows, find tiny-process-library
+if (WIN32)
+  option(USE_EXTERNAL_TINY_PROCESS_LIBRARY "Use external tiny-process-library." OFF)
+  if (USE_EXTERNAL_TINY_PROCESS_LIBRARY)
+    find_package(tiny-process-library QUIET)
+    if (NOT tiny-process-library_FOUND)
+      message (STATUS "Looking for tiny-process-library - not found")
+      BUILD_ERROR ("Missing: tiny-process-library, even if USE_EXTERNAL_TINY_PROCESS_LIBRARY was enabled.")
+    else()
+      message (STATUS "Looking for tiny-process-library - found")
+    endif()
+  endif()
+endif()

deps/CMakeLists.txt

@@ -4,4 +4,8 @@ if (NOT CCD_FOUND)
   add_subdirectory(libccd)
 endif()
 # add_subdirectory(ann)
-# add_subdirectory(fcl)
+# add_subdirectory(fcl
+
+if (WIN32 AND NOT USE_EXTERNAL_TINY_PROCESS_LIBRARY)
+  add_subdirectory(tiny-process-library)
+endif()

deps/tiny-process-library/CMakeLists.txt

@@ -0,0 +1,52 @@
+include(FetchContent)
+FetchContent_Declare(
+  tinyprocesslibrary
+  GIT_REPOSITORY https://gitlab.com/eidheim/tiny-process-library.git
+  GIT_TAG v2.0.2)
+
+FetchContent_GetProperties(tinyprocesslibrary)
+
+if(NOT tinyprocesslibrary_POPULATED)
+  FetchContent_Populate(tinyprocesslibrary)
+
+  # We don't want to install this library in the system, we instead
+  # compile it as an OBJECT library and embed in either the shared or
+  # static libraries that need it.
+  # From https://gitlab.kitware.com/cmake/cmake/-/issues/18935 it seems
+  # that OBJECT libraries that are not installed become INTERFACE when
+  # part of an EXPORT set.
+  # This behaviour allows setting transitively tiny-process-library infos
+  # to the consuming targets while not breaking the EXPORT process. In fact,
+  # the conversion to INTERFACE allows to add tiny-process-library to the
+  # targets of the EXPORT that contains targets linking against it.
+  # See also https://cmake.org/pipermail/cmake/2018-September/068250.html.
+
+  if(WIN32)
+    add_library(tiny-process-library OBJECT
+      ${tinyprocesslibrary_SOURCE_DIR}/process.cpp
+      ${tinyprocesslibrary_SOURCE_DIR}/process_win.cpp)
+    #If compiled using MSYS2, use sh to run commands
+    if(MSYS)
+      target_compile_definitions(tiny-process-library
+        PUBLIC MSYS_PROCESS_USE_SH)
+    endif()
+  else()
+    add_library(tiny-process-library OBJECT
+      ${tinyprocesslibrary_SOURCE_DIR}/process.cpp
+      ${tinyprocesslibrary_SOURCE_DIR}/process_unix.cpp)
+  endif()
+  add_library(tiny-process-library::tiny-process-library ALIAS tiny-process-library)
+
+  if(MSVC)
+    target_compile_definitions(tiny-process-library
+      PRIVATE /D_CRT_SECURE_NO_WARNINGS)
+  endif()
+
+  find_package(Threads REQUIRED)
+
+  target_link_libraries(tiny-process-library PRIVATE
+    ${CMAKE_THREAD_LIBS_INIT})
+  target_include_directories(tiny-process-library PUBLIC
+    $<BUILD_INTERFACE:${tinyprocesslibrary_SOURCE_DIR}>)
+
+endif()

gazebo/CMakeLists.txt

@@ -82,28 +82,35 @@ endif()
 gz_install_executable(gzserver)
 manpage(gzserver 1)
 
-# gazebo executable doesn't yet work on Windows
-if (NOT WIN32)
-  gz_add_executable(gazebo gazebo_main.cc)
-  target_link_libraries(gazebo
-    libgazebo
-    libgazebo_client
-    gazebo_common
-    gazebo_util
-    gazebo_transport
-    gazebo_physics
-    gazebo_sensors
-    gazebo_rendering
-    gazebo_msgs
-    gazebo_gui
-  )
-
-  gz_install_executable(gazebo)
-  manpage(gazebo 1)
+
+gz_add_executable(gazebo gazebo_main.cc)
+target_link_libraries(gazebo
+  libgazebo
+  libgazebo_client
+  gazebo_common
+  gazebo_util
+  gazebo_transport
+  gazebo_physics
+  gazebo_sensors
+  gazebo_rendering
+  gazebo_msgs
+  gazebo_gui
+)
+
+if(WIN32)
+  target_link_libraries(gazebo tiny-process-library::tiny-process-library)
 endif()
 
+gz_install_executable(gazebo)
+manpage(gazebo 1)
+
+
 gz_add_library(libgazebo Server.cc Master.cc gazebo.cc gazebo_shared.cc)
-set_target_properties(libgazebo PROPERTIES OUTPUT_NAME "gazebo")
+
+# On Windows calling libgazebo "gazebo" will conflict with the Gazebo executable
+if (NOT WIN32)
+  set_target_properties(libgazebo PROPERTIES OUTPUT_NAME "gazebo")
+endif()
 
 target_link_libraries(libgazebo
   gazebo_common

gazebo/gazebo_main.cc

@@ -14,24 +14,20 @@
  * limitations under the License.
  *
 */
+
+#ifndef _WIN32
 #include <sys/wait.h>
 #include <unistd.h>
 #include <signal.h>
 #include <sys/types.h>
+#else
+#include <process.hpp>
+#endif
 
 #include "gazebo/common/Console.hh"
 #include "gazebo/Server.hh"
 #include "gazebo/gui/GuiIface.hh"
 
-bool sig_killed = false;
-int status1, status2;
-// pid of server process
-pid_t pid1;
-// pid of client process
-pid_t pid2;
-bool killed1 = false;
-bool killed2 = false;
-
 /////////////////////////////////////////////////
 void help()
 {
@@ -77,6 +73,16 @@ void help()
   << "\n";
 }
 
+#ifndef _WIN32
+bool sig_killed = false;
+int status1, status2;
+// pid of server process
+pid_t pid1;
+// pid of client process
+pid_t pid2;
+bool killed1 = false;
+bool killed2 = false;
+
 /// \brief Try to kill a single process.
 /// \param[in] _pid Process ID.
 /// \param[in] _name Process name.
@@ -216,3 +222,85 @@ int main(int _argc, char **_argv)
 
   return returnValue;
 }
+
+#else
+
+std::atomic<bool> g_shouldExit = false;
+
+int main(int _argc, char **_argv)
+{
+  if (_argc >= 2 &&
+      (strcmp(_argv[1], "-h") == 0 || strcmp(_argv[1], "--help") == 0)) {
+    help();
+    return 0;
+  }
+
+  std::vector<std::string> argvServer;
+  std::vector<std::string> argvClient;
+
+  argvServer.push_back("gzserver");
+  argvClient.push_back("gzclient");
+
+  for (int i = 1; i < _argc; ++i)
+  {
+    argvServer.push_back(std::string(_argv[i]));
+    argvClient.push_back(std::string(_argv[i]));
+  }
+
+  // Start server
+  TinyProcessLib::Process server(argvServer);
+
+  // Start client
+  TinyProcessLib::Process client(argvClient);
+
+  // Wait
+  bool serverClosed = false;
+  bool clientClosed = false;
+  int serverExitCode = 0;
+  int clientExitCode = 0;
+
+  while (!g_shouldExit)
+  {
+    std::this_thread::sleep_for(std::chrono::milliseconds(20));
+
+    // Check if server and gui are still open, if they are closed
+    // close this process as well
+    serverClosed = server.try_get_exit_status(serverExitCode);
+    clientClosed = client.try_get_exit_status(clientExitCode);
+
+    if (serverClosed || clientClosed)
+    {
+      g_shouldExit = true;
+    }
+
+  }
+
+  // Cleanup
+  serverClosed = server.try_get_exit_status(serverExitCode);
+
+  if (!serverClosed)
+  {
+    server.kill();
+  }
+
+  clientClosed = client.try_get_exit_status(clientExitCode);
+
+  if (!clientClosed)
+  {
+    client.kill();
+  }
+
+  // Get exit status
+  serverExitCode = server.get_exit_status();
+  clientExitCode = client.get_exit_status();
+
+  int exitCode = 0;
+  if (serverExitCode != 0 || clientExitCode != 0)
+  {
+    exitCode = 1;
+  }
+
+  return exitCode;
+}
+
+#endif