add support for STREAM logging macros (#926)

* refactor template logic around feature combinations

Signed-off-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>

* add support for STREAM logging macros

Signed-off-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>

rclcpp/resource/logging.hpp.em

@@ -46,8 +46,8 @@
 
 @{
 from collections import OrderedDict
+from copy import deepcopy
 from rcutils.logging import feature_combinations
-from rcutils.logging import get_macro_parameters
 from rcutils.logging import get_suffix_from_features
 from rcutils.logging import severities
 from rcutils.logging import throttle_args
@@ -58,49 +58,70 @@ del throttle_params['get_time_point_value']
 throttle_params['clock'] = 'rclcpp::Clock that will be used to get the time point.'
 throttle_params.move_to_end('clock', last=False)
 
-excluded_features = ['named']
-def is_supported_feature_combination(feature_combination):
-    is_excluded = any([ef in feature_combination for ef in excluded_features])
-    return not is_excluded
+rclcpp_feature_combinations = OrderedDict()
+for combinations, feature in feature_combinations.items():
+    # skip feature combinations using 'named'
+    if 'named' in combinations:
+        continue
+    rclcpp_feature_combinations[combinations] = feature
+# add a stream variant for each available feature combination
+stream_arg = 'stream_arg'
+for combinations, feature in list(rclcpp_feature_combinations.items()):
+    combinations = ('stream', ) + combinations
+    feature = deepcopy(feature)
+    feature.params[stream_arg] = 'The argument << into a stringstream'
+    rclcpp_feature_combinations[combinations] = feature
+
+def get_rclcpp_suffix_from_features(features):
+    suffix = get_suffix_from_features(features)
+    if 'stream' in features:
+        suffix = '_STREAM' + suffix
+    return suffix
 }@
 @[for severity in severities]@
 /** @@name Logging macros for severity @(severity).
  */
 ///@@{
 #if (RCLCPP_LOG_MIN_SEVERITY > RCLCPP_LOG_MIN_SEVERITY_@(severity))
 // empty logging macros for severity @(severity) when being disabled at compile time
-@[ for feature_combination in [fc for fc in feature_combinations if is_supported_feature_combination(fc)]]@
-@{suffix = get_suffix_from_features(feature_combination)}@
+@[ for feature_combination in rclcpp_feature_combinations.keys()]@
+@{suffix = get_rclcpp_suffix_from_features(feature_combination)}@
 /// Empty logging macro due to the preprocessor definition of RCLCPP_LOG_MIN_SEVERITY.
 #define RCLCPP_@(severity)@(suffix)(...)
 @[ end for]@
 
 #else
-@[ for feature_combination in [fc for fc in feature_combinations if is_supported_feature_combination(fc)]]@
-@{suffix = get_suffix_from_features(feature_combination)}@
+@[ for feature_combination in rclcpp_feature_combinations.keys()]@
+@{suffix = get_rclcpp_suffix_from_features(feature_combination)}@
 // The RCLCPP_@(severity)@(suffix) macro is surrounded by do { .. } while (0)
 // to implement the standard C macro idiom to make the macro safe in all
 // contexts; see http://c-faq.com/cpp/multistmt.html for more information.
 /**
  * \def RCLCPP_@(severity)@(suffix)
  * Log a message with severity @(severity)@
-@[ if feature_combinations[feature_combination].doc_lines]@
+@[ if rclcpp_feature_combinations[feature_combination].doc_lines]@
  with the following conditions:
 @[ else]@
 .
 @[ end if]@
-@[ for doc_line in feature_combinations[feature_combination].doc_lines]@
+@[ for doc_line in rclcpp_feature_combinations[feature_combination].doc_lines]@
  * @(doc_line)
 @[ end for]@
  * \param logger The `rclcpp::Logger` to use
-@[ for param_name, doc_line in feature_combinations[feature_combination].params.items()]@
+@[ for param_name, doc_line in rclcpp_feature_combinations[feature_combination].params.items()]@
  * \param @(param_name) @(doc_line)
 @[ end for]@
+@[ if 'stream' not in feature_combination]@
  * \param ... The format string, followed by the variable arguments for the format string.
  * It also accepts a single argument of type std::string.
+@[ end if]@
  */
-@{params = get_macro_parameters(feature_combination).keys()}@
-#define RCLCPP_@(severity)@(suffix)(logger, @(''.join([p + ', ' for p in params]))...) \
+@{params = rclcpp_feature_combinations[feature_combination].params.keys()}@
+#define RCLCPP_@(severity)@(suffix)(logger@(''.join([', ' + p for p in params]))@
+@[ if 'stream' not in feature_combination]@
+, ...@
+@[ end if]@
+) \
   do { \
     static_assert( \
       ::std::is_same<typename std::remove_cv<typename std::remove_reference<decltype(logger)>::type>::type, \
@@ -118,14 +139,22 @@ def is_supported_feature_combination(feature_combination):
         return RCUTILS_RET_OK; \
     }; \
 @[ end if] \
-    RCUTILS_LOG_@(severity)@(suffix)_NAMED( \
+@[ if 'stream' in feature_combination]@
+    std::stringstream ss; \
+    ss << @(stream_arg); \
+@[ end if]@
+    RCUTILS_LOG_@(severity)@(get_suffix_from_features(feature_combination))_NAMED( \
 @{params = ['get_time_point' if p == 'clock' and 'throttle' in feature_combination else p for p in params]}@
 @[ if params]@
-@(''.join(['      ' + p + ', \\\n' for p in params]))@
+@(''.join(['      ' + p + ', \\\n' for p in params if p != stream_arg]))@
 @[ end if]@
       logger.get_name(), \
+@[ if 'stream' not in feature_combination]@
       rclcpp::get_c_string(RCLCPP_FIRST_ARG(__VA_ARGS__, "")), \
         RCLCPP_ALL_BUT_FIRST_ARGS(__VA_ARGS__,"")); \
+@[ else]@
+      "%s", rclcpp::get_c_string(ss.str())); \
+@[ end if]@
   } while (0)
 
 @[ end for]@

rclcpp/test/test_logging.cpp

@@ -113,6 +113,20 @@ TEST_F(TestLoggingMacros, test_logging_string) {
   EXPECT_EQ("message seven", g_last_log_event.message);
 }
 
+TEST_F(TestLoggingMacros, test_logging_stream) {
+  for (std::string i : {"one", "two", "three"}) {
+    RCLCPP_DEBUG_STREAM(g_logger, "message " << i);
+  }
+  EXPECT_EQ(3u, g_log_calls);
+  EXPECT_EQ("message three", g_last_log_event.message);
+
+  RCLCPP_DEBUG_STREAM(g_logger, 4 << "th message");
+  EXPECT_EQ("4th message", g_last_log_event.message);
+
+  RCLCPP_DEBUG_STREAM(g_logger, "message " << 5);
+  EXPECT_EQ("message 5", g_last_log_event.message);
+}
+
 TEST_F(TestLoggingMacros, test_logging_once) {
   for (int i : {1, 2, 3}) {
     RCLCPP_INFO_ONCE(g_logger, "message %d", i);