Redundant .c_str() usage in rclcpp_components triggers ament_clang_tidy warning #2717
Description
Bug report
Required Info:
- Operating System: Ubuntu 22.04
- Installation type: Binary
- Version or commit hash: Humble release branch (latest commit)
- DDS implementation: Fast-RTPS
- Client library: rclcpp
Steps to reproduce issue
- Clone the
rclcpprepository from the ROS 2 Humble branch. - Use the following code snippet in a file:
for (const auto & clazz : classes) { std::string name = clazz.c_str(); if (name.compare(class_name) == 0) { RCLCPP_DEBUG(logger, "Instantiate class %s", clazz.c_str()); std::shared_ptr<rclcpp_components::NodeFactory> node_factory = nullptr; try { node_factory = loader->createInstance<rclcpp_components::NodeFactory>(clazz); } catch (const std::exception & ex) { RCLCPP_ERROR(logger, "Failed to load library %s", ex.what()); return 1; } catch (...) { RCLCPP_ERROR(logger, "Failed to load library"); return 1; } auto wrapper = node_factory->create_node_instance(options); auto node = wrapper.get_node_base_interface(); node_wrappers.push_back(wrapper); exec.add_node(node); } }
- Run
ament_clang_tidyas part of the build process.
Here is my .clang-tidy config:
---
Checks: '-*,
performance-*,
-performance-unnecessary-value-param,
llvm-namespace-comment,
modernize-redundant-void-arg,
modernize-use-nullptr,
modernize-use-default,
modernize-use-override,
modernize-loop-convert,
modernize-make-shared,
modernize-make-unique,
misc-unused-parameters,
readability-named-parameter,
readability-redundant-smartptr-get,
readability-redundant-string-cstr,
readability-simplify-boolean-expr,
readability-container-size-empty,
readability-identifier-naming,
'
HeaderFilterRegex: ''
CheckOptions:
- key: llvm-namespace-comment.ShortNamespaceLines
value: '10'
- key: llvm-namespace-comment.SpacesBeforeComments
value: '2'
- key: misc-unused-parameters.StrictMode
value: '1'
- key: readability-braces-around-statements.ShortStatementLines
value: '2'
# type names
- key: readability-identifier-naming.ClassCase
value: CamelCase
- key: readability-identifier-naming.EnumCase
value: CamelCase
- key: readability-identifier-naming.UnionCase
value: CamelCase
# method names
- key: readability-identifier-naming.MethodCase
value: camelBack
# variable names
- key: readability-identifier-naming.VariableCase
value: lower_case
# class member names
- key: readability-identifier-naming.PrivateMemberCase
value: lower_case
- key: readability-identifier-naming.PrivateMemberSuffix
value: '_'
- key: readability-identifier-naming.ProtectedMemberCase
value: lower_case
- key: readability-identifier-naming.ProtectedMemberSuffix
value: '_'
# const static or global variables are UPPER_CASE
- key: readability-identifier-naming.EnumConstantCase
value: UPPER_CASE
- key: readability-identifier-naming.StaticConstantCase
value: UPPER_CASE
- key: readability-identifier-naming.ClassConstantCase
value: UPPER_CASE
- key: readability-identifier-naming.GlobalVariableCase
value: UPPER_CASE
...
Expected behavior
No warnings or errors during the ament_clang_tidy checks.
Actual behavior
The following warning is raised during the ament_clang_tidy test:
/path/ros_ws/build/my_ros_package/rclcpp_components/node_main_sensor_scan_generation_node.cpp:43:24: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
std::string name = clazz.c_str();
^~~~~~~~~~~~~
clazz
Additional information
The issue is caused by the redundant use of .c_str() when initializing a std::string from another std::string. This can be resolved by directly assigning clazz to name, as shown below:
std::string name = clazz;This change avoids unnecessary conversion and adheres to modern C++ best practices. However, the original code in the repository triggers the clang-tidy warning, leading to a failure in the ament_clang_tidy test. This issue can disrupt CI pipelines and testing workflows, especially for users relying on strict linting configurations.