YAML parameter parser (#235)

* Implement a basic YAML based parameter parser for ros2 nodes

* Add README file

* Fix the issues after moving from rcutils_yaml_param_parser to rcl_yaml_param_parser

  - rename folders from rcutils_yaml_param_parser to rcl_yaml_param_parser
  - rename project, header guards and include statements from rcutils_yaml_param_parser to rcl_yaml_param_parser
  - move type declaration in separat file and namespace new structures
  - Fix the code review comments from Mikael

* Few minor changes

   - Changed "params" string to "ros__parameters"
   - Add -Wall, -Wextra and -Wpedantic falgs
   - Fix the compile warning with the new flags

* Fix the changes made in the design of C structure

  - Remove the node_namespaces entry in rcl_params_t
  - Change the type of num_nodes and num_params to size_t

* depend on libyaml_vendor (#236)

* Fix cmake setting standard(C and C++) and add byte_array in C struct

*   Remove C11 so that it defaults to C99

* [rcl_yaml_param_parser] fix export symbols (#237)

* add visibility macros

* remove unused macro

* Support for multi level node and parameter name spaces

* Additional fixes and cleanups

  - Support for string namespace seperator
  - Provide parameter structure init function API
  - name cleanups

* off by 1

* Call yaml_parser_delete()

* fclose(yaml_file)

* free() allocated paths

* Call yaml_event_delete()

* completely deallcoate string array

* Few cleanup changes

  - Add install command into CMakelists.txt
  - Replace one of the zero_allocate with reallocate
  - Pass allocator state
  - Fix int32_t -> rcl_ret_t return value

* Don't include unistd.h

* Use size_t for array indices

* Just pass the allocator in the init function

rcl_yaml_param_parser/include/rcl_yaml_param_parser/parser.h

@@ -0,0 +1,60 @@
+// Copyright 2018 Apex.AI, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCL_YAML_PARAM_PARSER__PARSER_H_
+#define RCL_YAML_PARAM_PARSER__PARSER_H_
+
+#include <stdlib.h>
+
+#include "rcl_yaml_param_parser/types.h"
+#include "rcl_yaml_param_parser/visibility_control.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/// \brief Init param structure
+/// \param[in] allocator memory allocator to be used
+/// \return a pointer to param structure on success or NULL on failure
+RCL_YAML_PARAM_PARSER_PUBLIC
+rcl_params_t * rcl_yaml_node_struct_init(
+  const rcutils_allocator_t allocator);
+
+/// \brief Free param structure
+/// \param[in] params_st points to the populated paramter struct
+RCL_YAML_PARAM_PARSER_PUBLIC
+void rcl_yaml_node_struct_fini(
+  rcl_params_t * params_st);
+
+/// \brief Parse the YAML file, initialize and populate params_st
+/// \param[in] file_path is the path to the YAML file
+/// \param[in/out] params_st points to the populated paramter struct
+/// \return true on success and false on failure
+RCL_YAML_PARAM_PARSER_PUBLIC
+bool rcl_parse_yaml_file(
+  const char * file_path,
+  rcl_params_t * params_st);
+
+/// \brief Print the parameter structure to stdout
+/// \param[in] params_st points to the populated parameter struct
+RCL_YAML_PARAM_PARSER_PUBLIC
+void rcl_yaml_node_struct_print(
+  const rcl_params_t * const params_st);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // RCL_YAML_PARAM_PARSER__PARSER_H_

rcl_yaml_param_parser/include/rcl_yaml_param_parser/types.h

@@ -0,0 +1,87 @@
+// Copyright 2018 Apex.AI, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef RCL_YAML_PARAM_PARSER__TYPES_H_
+#define RCL_YAML_PARAM_PARSER__TYPES_H_
+
+#include "rcl/allocator.h"
+#include "rcutils/types/string_array.h"
+
+/// \typedef rcl_bool_array_t
+/// \brief Array of bool values
+typedef struct rcl_bool_array_s
+{
+  bool * values;
+  size_t size;
+} rcl_bool_array_t;
+
+/// \typedef rcl_int64_array_t
+/// \brief Array of int64_t values
+typedef struct rcl_int64_array_s
+{
+  int64_t * values;
+  size_t size;
+} rcl_int64_array_t;
+
+/// \typedef rcl_double_array_t
+/// \brief Array of double values
+typedef struct rcl_double_array_s
+{
+  double * values;
+  size_t size;
+} rcl_double_array_t;
+
+/// \typedef rcl_byte_array_t
+/// \brief Array of byte values
+typedef struct rcl_byte_array_s
+{
+  uint8_t * values;
+  size_t size;
+} rcl_byte_array_t;
+
+/// \typedef rcl_variant_t
+/// \brief variant_t stores the value of a parameter
+/// Only one pointer in this struct will store the value
+typedef struct rcl_variant_s
+{
+  bool * bool_value;  ///< If bool, gets stored here
+  int64_t * integer_value;  ///< If integer, gets stored here
+  double * double_value;  ///< If double, gets stored here
+  char * string_value;  ///< If string, gets stored here
+  rcl_byte_array_t * byte_array_value;  ///< If array of bytes
+  rcl_bool_array_t * bool_array_value;  ///< If array of bool's
+  rcl_int64_array_t * integer_array_value;  ///< If array of integers
+  rcl_double_array_t * double_array_value;  ///< If array of doubles
+  rcutils_string_array_t * string_array_value;  ///< If array of strings
+} rcl_variant_t;
+
+/// \typedef rcl_node_params_t
+/// \brief node_params_t stores all the parameters(key:value) of a single node
+typedef struct rcl_node_params_s
+{
+  char ** parameter_names;  ///< Array of parameter names (keys)
+  rcl_variant_t * parameter_values;  ///< Array of coressponding parameter values
+  size_t num_params;  ///< Number of parameters in the node
+} rcl_node_params_t;
+
+/// \typedef rcl_params_t
+/// \brief params_t stores all the parameters of all nodes of a process
+typedef struct rcl_params_s
+{
+  char ** node_names;  ///< List of names of the node
+  rcl_node_params_t * params;  ///<  Array of parameters
+  size_t num_nodes;       ///< Number of nodes
+  rcl_allocator_t allocator;  ///< Allocator used
+} rcl_params_t;
+
+#endif  // RCL_YAML_PARAM_PARSER__TYPES_H_

rcl_yaml_param_parser/include/rcl_yaml_param_parser/visibility_control.h

@@ -0,0 +1,58 @@
+// Copyright 2015 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCL_YAML_PARAM_PARSER__VISIBILITY_CONTROL_H_
+#define RCL_YAML_PARAM_PARSER__VISIBILITY_CONTROL_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+// This logic was borrowed (then namespaced) from the examples on the gcc wiki:
+//     https://gcc.gnu.org/wiki/Visibility
+
+#if defined _WIN32 || defined __CYGWIN__
+  #ifdef __GNUC__
+    #define RCL_YAML_PARAM_PARSER_EXPORT __attribute__ ((dllexport))
+    #define RCL_YAML_PARAM_PARSER_IMPORT __attribute__ ((dllimport))
+  #else
+    #define RCL_YAML_PARAM_PARSER_EXPORT __declspec(dllexport)
+    #define RCL_YAML_PARAM_PARSER_IMPORT __declspec(dllimport)
+  #endif
+  #ifdef RCL_YAML_PARAM_PARSER_BUILDING_DLL
+    #define RCL_YAML_PARAM_PARSER_PUBLIC RCL_YAML_PARAM_PARSER_EXPORT
+  #else
+    #define RCL_YAML_PARAM_PARSER_PUBLIC RCL_YAML_PARAM_PARSER_IMPORT
+  #endif
+  #define RCL_YAML_PARAM_PARSER_PUBLIC_TYPE RCL_YAML_PARAM_PARSER_PUBLIC
+  #define RCL_YAML_PARAM_PARSER_LOCAL
+#else
+  #define RCL_YAML_PARAM_PARSER_EXPORT __attribute__ ((visibility("default")))
+  #define RCL_YAML_PARAM_PARSER_IMPORT
+  #if __GNUC__ >= 4
+    #define RCL_YAML_PARAM_PARSER_PUBLIC __attribute__ ((visibility("default")))
+    #define RCL_YAML_PARAM_PARSER_LOCAL  __attribute__ ((visibility("hidden")))
+  #else
+    #define RCL_YAML_PARAM_PARSER_PUBLIC
+    #define RCL_YAML_PARAM_PARSER_LOCAL
+  #endif
+  #define RCL_YAML_PARAM_PARSER_PUBLIC_TYPE
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // RCL_YAML_PARAM_PARSER__VISIBILITY_CONTROL_H_