feat(paths): Improve detection of ROS package paths

Nix installs all ros packages in their own separate install prefix. This
breaks some default assumption we had, in particular in paths fallback
when package:// cannot be resolved. We use to assume that we could
fallback to a path relative to mc_env_description, this is no longer
possible. In addition we explicitely check that manually provided
fallback paths actually exist.

Instead we make mc_env_description, mc_int_obj_description and
jvrc_description paths detected at compile-time available through
mc_rtc/config.h. This further simplifies cmake/test logic as a bonus

In addition, fix an issue in find_description_package that would cause
duplicated share/jvrc1_description/share/jvrc1_description. It seems to
be an odd edge-case of cmake's set(...) function with
variable-of-variables

Author: arntanguy

CMakeLists.txt

@@ -39,8 +39,6 @@ set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 project(${PROJECT_NAME} C CXX)
 set(MC_RTC_SOURCE_DIR "${PROJECT_SOURCE_DIR}")
 
-set_default_cmake_build_type(RelWithDebInfo)
-
 if(NOT DEFINED MC_RTC_INSTALL_PREFIX)
   set(MC_RTC_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
 endif()
@@ -51,6 +49,19 @@ else()
   set(MC_RTC_LOADER_DEBUG_SUFFIX "")
 endif()
 
+set_default_cmake_build_type(RelWithDebInfo)
+
+# Check for Nix build environment
+if(DEFINED ENV{NIX_BUILD_CORES}
+   OR DEFINED ENV{NIX_STORE}
+   OR DEFINED ENV{IN_NIX_SHELL}
+)
+  set(MC_RTC_BUILD_IN_NIX TRUE)
+  message(STATUS "Detected Nix build environment")
+else()
+  set(MC_RTC_BUILD_IN_NIX FALSE)
+endif()
+
 option(GENERATE_COVERAGE "Generate coverage data" FALSE)
 if("${CMAKE_CXX_FLAGS}" MATCHES "--coverage")
   set(GENERATE_COVERAGE
@@ -225,17 +236,18 @@ macro(find_description_package PACKAGE)
             "Your ${PACKAGE} does not define where to find the data, please update."
         )
       else()
-        set(${PACKAGE_PATH_VAR} "${${PACKAGE}_SOURCE_PREFIX}")
+        set("${PACKAGE_PATH_VAR}" "${${PACKAGE}_SOURCE_PREFIX}")
       endif()
     else()
-      set(${PACKAGE_PATH_VAR} "${${PACKAGE}_INSTALL_PREFIX}")
+      set("${PACKAGE_PATH_VAR}" "${${PACKAGE}_INSTALL_PREFIX}")
     endif()
     # Cleanup the path provided by CMake
-    get_filename_component(${PACKAGE_PATH_VAR} "${${PACKAGE_PATH_VAR}}" REALPATH)
+    get_filename_component("${PACKAGE_PATH_VAR}" "${${PACKAGE_PATH_VAR}}" REALPATH)
   endif()
   message("-- Found ${PACKAGE}: ${${PACKAGE_PATH_VAR}}")
 endmacro()
 
+find_description_package(jvrc_description)
 find_description_package(mc_env_description)
 find_description_package(mc_int_obj_description)
 
@@ -293,7 +305,7 @@ else()
 endif()
 
 configure_file(
-  ${PROJECT_SOURCE_DIR}/include/mc_rtc/config.h.cmake.in
+  ${PROJECT_SOURCE_DIR}/include/mc_rtc/config.in.h
   ${CMAKE_CURRENT_BINARY_DIR}/include/mc_rtc/config.h
 )
 

include/mc_rtc/config.h.cmake.in include/mc_rtc/config.in.hinclude/mc_rtc/config.h.cmake.in renamed to include/mc_rtc/config.in.h

@@ -9,7 +9,9 @@
 namespace mc_rtc
 {
 
+constexpr auto JVRC_DESCRIPTION_PATH = "${JVRC_DESCRIPTION_PATH}";
 constexpr auto MC_ENV_DESCRIPTION_PATH = "${MC_ENV_DESCRIPTION_PATH}";
+constexpr auto MC_INT_OBJ_DESCRIPTION_PATH = "${MC_INT_OBJ_DESCRIPTION_PATH}";
 constexpr auto INSTALL_PREFIX = "${MC_RTC_INSTALL_PREFIX}/";
 constexpr auto MC_ROBOTS_INSTALL_PREFIX = "${MC_ROBOTS_RUNTIME_DESTINATION_PREFIX}/";
 constexpr auto MC_OBSERVERS_INSTALL_PREFIX = "${MC_OBSERVERS_RUNTIME_DESTINATION_PREFIX}/";
@@ -19,4 +21,5 @@ constexpr auto DATA_PATH = "${CMAKE_INSTALL_PREFIX}/share/mc_rtc/";
 constexpr auto CONF_PATH = "${CMAKE_INSTALL_PREFIX}/etc/mc_rtc.yaml";
 constexpr bool MC_RTC_SUPPORT_ROS = ${MC_RTC_HAS_ROS_SUPPORT};
 constexpr auto JSON_SCHEMA_PATH = "${MC_RTC_JSON_SCHEMA_PATH}/";
-}
+constexpr bool MC_RTC_BUILD_IN_NIX = "${MC_RTC_BUILD_IN_NIX}";
+} // namespace mc_rtc

src/mc_robots/CMakeLists.txt

@@ -77,20 +77,9 @@ if(EXISTS "${MC_ENV_DESCRIPTION_PATH}")
   )
 endif()
 
-find_description_package(jvrc_description)
 add_robot(jvrc1)
 if(TARGET jvrc1)
-  set_target_properties(
-    jvrc1
-    PROPERTIES
-      COMPILE_FLAGS
-      "-DMC_ROBOTS_EXPORTS -DJVRC_DESCRIPTION_PATH=\"${JVRC_DESCRIPTION_PATH}\""
-  )
+  set_target_properties(jvrc1 PROPERTIES COMPILE_FLAGS "-DMC_ROBOTS_EXPORTS")
 else()
-  set_target_properties(
-    mc_rbdyn
-    PROPERTIES
-      COMPILE_FLAGS
-      "-DMC_ROBOTS_EXPORTS -DJVRC_DESCRIPTION_PATH=\"${JVRC_DESCRIPTION_PATH}\""
-  )
+  set_target_properties(mc_rbdyn PROPERTIES COMPILE_FLAGS "-DMC_ROBOTS_EXPORTS")
 endif()

src/mc_robots/jvrc1.cpp

@@ -2,18 +2,12 @@
  * Copyright 2015-2019 CNRS-UM LIRMM, CNRS-AIST JRL
  */
 
-#ifndef JVRC_DESCRIPTION_PATH
-#  error "JVRC_DESCRIPTION_PATH must be defined to build this RobotModule"
-#endif
-
-#define JVRC_VAL(x) #x
-#define JVRC_VAL_VAL(x) JVRC_VAL(x)
-
 #include "jvrc1.h"
 
 #include <mc_rbdyn/Device.h>
 #include <mc_rbdyn/RobotModuleMacros.h>
 
+#include <mc_rtc/config.h>
 #include <mc_rtc/logging.h>
 
 #include <RBDyn/parsers/urdf.h>
@@ -33,8 +27,7 @@ mc_rbdyn::DevicePtr JVRC1DummySpeaker::clone() const
   return mc_rbdyn::DevicePtr(dummy);
 }
 
-JVRC1RobotModule::JVRC1RobotModule(bool fixed, bool filter_mimics)
-: RobotModule(std::string(JVRC_VAL_VAL(JVRC_DESCRIPTION_PATH)), "jvrc1")
+JVRC1RobotModule::JVRC1RobotModule(bool fixed, bool filter_mimics) : RobotModule(mc_rtc::JVRC_DESCRIPTION_PATH, "jvrc1")
 {
   _canonicalParameters = {"JVRC1"};
 

src/mc_rtc/path.cpp

@@ -1,4 +1,5 @@
 #include <mc_rtc/config.h>
+#include <mc_rtc/logging.h>
 #include <mc_rtc/path.h>
 #include <fmt/format.h>
 
@@ -69,15 +70,29 @@ fs::path convertURI(const std::string & uri, std::string_view default_dir)
     }
 #  endif
     // Fallback for non-ROS builds or when ROS package is not found
-    if(pkg == "jvrc_description") { pkg = (MC_ENV_DESCRIPTION_PATH / ".." / "jvrc_description").string(); }
-    else if(pkg == "mc_env_description") { pkg = MC_ENV_DESCRIPTION_PATH.string(); }
-    else if(pkg == "mc_int_obj_description")
-    {
-      pkg = (MC_ENV_DESCRIPTION_PATH / ".." / "mc_int_obj_description").string();
-    }
+    if(pkg == "jvrc_description") { pkg = mc_rtc::JVRC_DESCRIPTION_PATH; }
+    else if(pkg == "mc_env_description") { pkg = mc_rtc::MC_ENV_DESCRIPTION_PATH; }
+    else if(pkg == "mc_int_obj_description") { pkg = mc_rtc::MC_INT_OBJ_DESCRIPTION_PATH; }
     else
-    {
-      pkg = default_dir;
+    { // could not resolve path using ament index, check for default_dir
+      if(default_dir.empty())
+      {
+        mc_rtc::log::error_and_throw("[mc_rtc::convertURI] Could not resolve path to ROS package path package '{}' in "
+                                     "URI '{}', and no default_dir was provided",
+                                     pkg, uri);
+        return uri;
+      }
+      else if(!fs::exists(default_dir) || !fs::is_directory(default_dir))
+      {
+        mc_rtc::log::error_and_throw("[mc_rtc::convertURI] Could not resolve path to ROS package path package '{}' in "
+                                     "URI '{}', and default_dir '{}' does not exist or is not a directory",
+                                     pkg, uri, default_dir);
+        return uri;
+      }
+      else
+      { // default_dir exists
+        pkg = default_dir;
+      }
     }
 #else
     pkg = "/assets/" + pkg;

tests/CMakeLists.txt

@@ -102,11 +102,6 @@ mc_rtc_test(testLogger mc_rbdyn)
 mc_rtc_test(testLogUtils mc_rbdyn)
 mc_rtc_test(testRobotModule mc_rbdyn)
 mc_rtc_test(testRobotModule_visual mc_rbdyn)
-find_description_package(jvrc_description)
-set_target_properties(
-  testRobotModule PROPERTIES COMPILE_FLAGS
-                             "-DJVRC_DESCRIPTION_PATH=\"${JVRC_DESCRIPTION_PATH}\""
-)
 mc_rtc_test(testCanonicalRobot mc_rbdyn)
 mc_rtc_test(testSolverBackend mc_tasks)
 

tests/testRobotModule.cpp

@@ -5,19 +5,13 @@
 #include "utils.h"
 
 #include <mc_rbdyn/Robots.h>
+#include <mc_rtc/config.h>
 
 #include <boost/filesystem.hpp>
 namespace bfs = boost::filesystem;
 
 #include <boost/test/unit_test.hpp>
 
-#ifndef JVRC_DESCRIPTION_PATH
-#  error "JVRC_DESCRIPTION_PATH must be defined to build this RobotModule"
-#endif
-
-#define JVRC_VAL(x) #x
-#define JVRC_VAL_VAL(x) JVRC_VAL(x)
-
 static std::string JVRC1_DATA = fmt::format(R"(
 path: "{}"
 name: jvrc1
@@ -77,7 +71,7 @@ default_attitude: [1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.8275]
   X_p_f:
     translation: [0.1, 0, 0]
 )",
-                                            JVRC_VAL_VAL(JVRC_DESCRIPTION_PATH));
+                                            mc_rtc::JVRC_DESCRIPTION_PATH);
 
 BOOST_AUTO_TEST_CASE(TestRobotModule)
 {