Enable tracing by default if LTTng is available

Also removed the colcon.meta file that implicitly enabled tracing anyway

.gitlab-ci.yml

@@ -32,7 +32,6 @@ build_enabled:
 
 build:
   script:
-    - rm colcon.meta
     - colcon build --symlink-install --packages-up-to $PACKAGES_LIST
     - . install/local_setup.sh
     - colcon test --packages-select $PACKAGES_LIST

README.md

@@ -4,7 +4,7 @@ Tracing tools for ROS 2.
 
 ## Building
 
-If tracing is not enabled when building, or if LTTng is not found, then this package will not do anything.
+If the `TRACETOOLS_ENABLED` option is disabled during build or if LTTng is not found, then this package will not do anything.
 
 To enable tracing:
 
@@ -16,9 +16,9 @@ To enable tracing:
     $ sudo apt-get install python3-babeltrace python3-lttng
     ```
     Note: the LTTng stable 2.10 PPA is used to get newer versions of the packages.
-2. Build with the `WITH_LTTNG` flag:
+2. Build
     ```
-    $ colcon build --cmake-args " -DWITH_LTTNG=ON"
+    $ colcon build
     ```
 3. Source and check that tracing is enabled:
     ```

colcon.meta

@@ -1,14 +0,0 @@
-{
-  "names": {
-    "tracetools": {
-      "cmake-args": [
-        "-DWITH_LTTNG=ON",
-      ],
-    },
-    "tracetools_test": {
-      "cmake-args": [
-        "-DWITH_LTTNG=ON",
-      ],
-    },
-  },
-}

tracetools/CMakeLists.txt

@@ -12,21 +12,17 @@ endif()
 
 find_package(ament_cmake_ros REQUIRED)
 
-option(WITH_LTTNG "Include support for tracing with LTTng" OFF)
+option(WITH_LTTNG "Enable support for tracing with LTTng" ON)
 if(WITH_LTTNG)
-  # Try to find LTTng
-  find_package(PkgConfig REQUIRED)
-  pkg_check_modules(LTTNG REQUIRED lttng-ust)
-endif()
-if(LTTNG_FOUND)
-  set(LTTNG_TP_FILES
-    include/tracetools/tp_call.h
-    src/tp_call.c
-  )
+  # Set TRACING_ENABLED if we can find lttng-ust
+  # TODO: Should these be quiet?
+  find_package(PkgConfig)
+  if(PkgConfig_FOUND)
+    pkg_check_modules(LTTNG lttng-ust)
+    if(LTTNG_FOUND)
       set(TRACING_ENABLED TRUE)
-  message("LTTng found: tracing enabled")
-elseif(WITH_LTTNG)
-  message("LTTng NOT found: tracing disabled")
+    endif()
+  endif()
 endif()
 
 include_directories(include)
@@ -54,7 +50,10 @@ set(SOURCES
   src/utils.cpp
 )
 if(TRACING_ENABLED)
-  list(APPEND SOURCES ${LTTNG_TP_FILES})
+  list(APPEND SOURCES
+    include/tracetools/tp_call.h
+    src/tp_call.c)
+
 endif()
 
 add_library(${PROJECT_NAME} SHARED ${SOURCES})

tracetools_test/CMakeLists.txt

@@ -12,7 +12,18 @@ endif()
 
 find_package(ament_cmake REQUIRED)
 
-option(WITH_LTTNG "Include support for tracing with LTTng" OFF)
+option(WITH_LTTNG "Enable support for tracing with LTTng" ON)
+if(WITH_LTTNG)
+  # Set TRACING_ENABLED if we can find lttng-ust
+  # TODO should these be quiet?
+  find_package(PkgConfig)
+  if(PkgConfig_FOUND)
+    pkg_check_modules(LTTNG lttng-ust)
+    if(LTTNG_FOUND)
+      set(TRACING_ENABLED TRUE)
+    endif()
+  endif()
+endif()
 
 # Tests
 if(BUILD_TESTING)
@@ -119,12 +130,7 @@ if(BUILD_TESTING)
   ament_lint_auto_find_test_dependencies()
 
   # Only build tracing tests if LTTng is enabled and found
-  if(WITH_LTTNG)
-    find_package(PkgConfig REQUIRED)
-    pkg_check_modules(LTTNG REQUIRED lttng-ust)
-    if(LTTNG_FOUND)
-      message("LTTng found: tracing tests enabled")
-
+  if(TRACING_ENABLED)
     find_package(ament_cmake_pytest REQUIRED)
 
     # Run each test in its own pytest invocation
@@ -149,7 +155,6 @@ if(BUILD_TESTING)
         )
     endforeach()
   endif()
-  endif()
 endif()
 
 ament_package()