Add cJSON module (#889)

Moving CJSON into a common module so it can be effectively reused across
the C CRT repositories without having to embed multiple copies of CJSON.

Commit log:
* Added CJSON module implementation
* Adjusted JSON module to fit code style, added code documentation
* Fixed formatting issues, added clang-format files to skip formatting cJSON
* Added files to ignore clang-tidy in externals directory
* Further adjustments to work around clang-tidy on external, adjustment to fix compiling on Windows
* More formatting fixes
* JSON module header clang-tidy fixes
* Initial design of AWS JSON module
* Redesign with new interface that does not expose cJSON
* Fixed the JSON module crashing.
* Added additional JSON testing
* Fixed formatting issues, used struct instead of void*
* Additional clang-format fixes
* Added documentation, further clang-format fixes
* Fixes for Windows CI
* Moved JSON code into source to attempt to fix Windows CI
* Modified to fit C repository style and to use C repo error style
* Fixed JSON tests
* Added AWS_COMMON_API to API functions
* Added missing AWS_COMMON_API
* Removed AWS_COMMON_API from struct in JSON module
* Clang-tidy fixes for CJSON
* Merged latest version of aws-c-common and testing including cJSON C file instead of header.
* Revert include change, fix ifndef
* Code review changes
* Further code review changes
* Upgraded cJSON to latest version
* Larger code review changes
* Adjusted cJSON version from main to latest release, adjusted CMAKE file to not include cJSON headers
* Fix warnings due to const casting
* Fixed issues with tests, minor API adjustment as needed to get everything working
* fixed compiling issue on CI, ran clang-format
* Another clang format fix and fixing lgtm issue
* Got the print functions no longer leaking memory
* Removed warnings of unused allocator parameter in JSON functions
* Code review changes to JSON module
* Additional code review changes and clang format pass
* Fixed issues where Windows was not building due to tests failing, hopefully fixed clang-tidy issues on cJSON files
* Fixed header and source for JSON module having different arguments causing vc14 to fail
* Further fixes for clang-tidy and vc14
* Adjusted code based on review
* Added additional checks before cleaning byte buffer
* Fixed lgtm bot issue and hopefully issue causing CI to fail
* Code review update: Naming adjusted and functionality slightly tweaked
* Adjusted JSON string functions to append to byte buffer. Naming adjustment
* Use secure byte buffer appends, fix test condition check order
* Fix JSON tests failing on Linux

CMakeLists.txt

@@ -37,6 +37,9 @@ file(GLOB AWS_COMMON_HEADERS
         "include/aws/common/*.inl"
         )
 
+file (GLOB AWS_COMMON_EXTERNAL_HEADERS
+        "include/aws/common/external/*.h")
+
 file(GLOB AWS_TEST_HEADERS
         "include/aws/testing/*.h"
         )
@@ -50,6 +53,9 @@ file(GLOB AWS_COMMON_SRC
         "source/*.c"
         )
 
+file (GLOB AWS_COMMON_EXTERNAL_SRC
+        "source/external/*.c")
+
 option(AWS_NUM_CPU_CORES "Number of CPU cores of the target machine. Useful when cross-compiling." 0)
 
 if (WIN32)
@@ -150,13 +156,15 @@ file(GLOB COMMON_HEADERS
         ${AWS_COMMON_HEADERS}
         ${AWS_COMMON_OS_HEADERS}
         ${AWS_COMMON_PRIV_HEADERS}
+        ${AWS_COMMON_EXTERNAL_HEADERS}
         ${AWS_TEST_HEADERS}
         )
 
 file(GLOB COMMON_SRC
         ${AWS_COMMON_SRC}
         ${AWS_COMMON_OS_SRC}
         ${AWS_COMMON_ARCH_SRC}
+        ${AWS_COMMON_EXTERNAL_SRC}
         )
 
 
@@ -195,6 +203,8 @@ target_include_directories(${PROJECT_NAME} PUBLIC
 target_include_directories(${PROJECT_NAME} PUBLIC
         $<BUILD_INTERFACE:${GENERATED_INCLUDE_DIR}>)
 
+target_compile_definitions(${PROJECT_NAME} PRIVATE -DCJSON_HIDE_SYMBOLS)
+
 # Enable SIMD encoder if the compiler supports the right features
 simd_add_definitions(${PROJECT_NAME})
 

include/aws/common/external/.clang-format

@@ -0,0 +1,2 @@
+DisableFormat: true
+SortIncludes: false

include/aws/common/json.h

@@ -0,0 +1,348 @@
+#ifndef AWS_COMMON_JSON_H
+#define AWS_COMMON_JSON_H
+
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+#include <aws/common/byte_buf.h>
+#include <aws/common/common.h>
+
+struct aws_json_value;
+
+// ====================
+// Create and pass type
+
+/**
+ * Creates a new string aws_json_value with the given string and returns a pointer to it.
+ *
+ * Note: You will need to free the memory for the aws_json_value using aws_json_destroy on the aws_json_value or
+ * on the object/array containing the aws_json_value.
+ * @param string A byte pointer to the string you want to store in the aws_json_value
+ * @param allocator The allocator to use when creating the value
+ * @return A new string aws_json_value
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_string(struct aws_allocator *allocator, struct aws_byte_cursor string);
+
+/**
+ * Creates a new number aws_json_value with the given number and returns a pointer to it.
+ *
+ * Note: You will need to free the memory for the aws_json_value using aws_json_destroy on the aws_json_value or
+ * on the object/array containing the aws_json_value.
+ * @param number The number you want to store in the aws_json_value
+ * @param allocator The allocator to use when creating the value
+ * @return A new number aws_json_value
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_number(struct aws_allocator *allocator, double number);
+
+/**
+ * Creates a new array aws_json_value and returns a pointer to it.
+ *
+ * Note: You will need to free the memory for the aws_json_value using aws_json_destroy on the aws_json_value or
+ * on the object/array containing the aws_json_value.
+ * Deleting this array will also destroy any aws_json_values it contains.
+ * @param allocator The allocator to use when creating the value
+ * @return A new array aws_json_value
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_array(struct aws_allocator *allocator);
+
+/**
+ * Creates a new boolean aws_json_value with the given boolean and returns a pointer to it.
+ *
+ * Note: You will need to free the memory for the aws_json_value using aws_json_destroy on the aws_json_value or
+ * on the object/array containing the aws_json_value.
+ * @param boolean The boolean you want to store in the aws_json_value
+ * @param allocator The allocator to use when creating the value
+ * @return A new boolean aws_json_value
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_boolean(struct aws_allocator *allocator, bool boolean);
+
+/**
+ * Creates a new null aws_json_value and returns a pointer to it.
+ *
+ * Note: You will need to free the memory for the aws_json_value using aws_json_destroy on the aws_json_value or
+ * on the object/array containing the aws_json_value.
+ * @param allocator The allocator to use when creating the value
+ * @return A new null aws_json_value
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_null(struct aws_allocator *allocator);
+
+/**
+ * Creates a new object aws_json_value and returns a pointer to it.
+ *
+ * Note: You will need to free the memory for the aws_json_value using aws_json_destroy on the aws_json_value or
+ * on the object/array containing the aws_json_value.
+ * Deleting this object will also destroy any aws_json_values it contains.
+ * @param allocator The allocator to use when creating the value
+ * @return A new object aws_json_value
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_object(struct aws_allocator *allocator);
+// ====================
+
+// ====================
+// Value getters
+
+/**
+ * Gets the string of a string aws_json_value.
+ * @param value The string aws_json_value.
+ * @param output The string
+ * @return AWS_OP_SUCESS if the value is a string, otherwise AWS_OP_ERR.
+ */
+AWS_COMMON_API
+int aws_json_value_get_string(const struct aws_json_value *value, struct aws_byte_cursor *output);
+
+/**
+ * Gets the number of a number aws_json_value.
+ * @param value The number aws_json_value.
+ * @param output The number
+ * @return AWS_OP_SUCESS if the value is a number, otherwise AWS_OP_ERR.
+ */
+AWS_COMMON_API
+int aws_json_value_get_number(const struct aws_json_value *value, double *output);
+
+/**
+ * Gets the boolean of a boolean aws_json_value.
+ * @param value The boolean aws_json_value.
+ * @param output The boolean
+ * @return AWS_OP_SUCESS if the value is a boolean, otherwise AWS_OP_ERR.
+ */
+AWS_COMMON_API
+int aws_json_value_get_boolean(const struct aws_json_value *value, bool *output);
+// ====================
+
+// ====================
+// Object API
+
+/**
+ * Adds a aws_json_value to a object aws_json_value.
+ *
+ * Note that the aws_json_value will be destroyed when the aws_json_value object is destroyed
+ * by calling "aws_json_destroy()"
+ * @param object The object aws_json_value you want to add a value to.
+ * @param key The key to add the aws_json_value at.
+ * @param value The aws_json_value you want to add.
+ * @return AWS_OP_SUCCESS if adding was successful.
+ *          Will return AWS_OP_ERROR if the object passed is invalid or if the passed key
+ *          is already in use in the object.
+ */
+AWS_COMMON_API
+int aws_json_value_add_to_object(
+    struct aws_json_value *object,
+    struct aws_byte_cursor key,
+    struct aws_json_value *value);
+
+/**
+ * Returns the aws_json_value at the given key.
+ * @param object The object aws_json_value you want to get the value from.
+ * @param key The key that the aws_json_value is at. Is case sensitive.
+ * @return The aws_json_value at the given key, otherwise NULL.
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_get_from_object(const struct aws_json_value *object, struct aws_byte_cursor key);
+
+/**
+ * Checks if there is a aws_json_value at the given key.
+ * @param object The value aws_json_value you want to check a key in.
+ * @param key The key that you want to check. Is case sensitive.
+ * @return True if a aws_json_value is found.
+ */
+AWS_COMMON_API
+bool aws_json_value_has_key(const struct aws_json_value *object, struct aws_byte_cursor key);
+
+/**
+ * Removes the aws_json_value at the given key.
+ * @param object The object aws_json_value you want to remove a aws_json_value in.
+ * @param key The key that the aws_json_value is at. Is case sensitive.
+ * @return AWS_OP_SUCCESS if the aws_json_value was removed.
+ *          Will return AWS_OP_ERR if the object passed is invalid or if the value
+ *          at the key cannot be found.
+ */
+AWS_COMMON_API
+int aws_json_value_remove_from_object(struct aws_json_value *object, struct aws_byte_cursor key);
+// ====================
+
+// ====================
+// Array API
+
+/**
+ * Adds a aws_json_value to the given array aws_json_value.
+ *
+ * Note that the aws_json_value will be destroyed when the aws_json_value array is destroyed
+ * by calling "aws_json_destroy()"
+ * @param array The array aws_json_value you want to add an aws_json_value to.
+ * @param value The aws_json_value you want to add.
+ * @return AWS_OP_SUCCESS if adding the aws_json_value was successful.
+ *          Will return AWS_OP_ERR if the array passed is invalid.
+ */
+AWS_COMMON_API
+int aws_json_value_add_array_element(struct aws_json_value *array, const struct aws_json_value *value);
+
+/**
+ * Returns the aws_json_value at the given index in the array aws_json_value.
+ * @param array The array aws_json_value.
+ * @param index The index of the aws_json_value you want to access.
+ * @return A pointer to the aws_json_value at the given index in the array, otherwise NULL.
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_get_array_element(const struct aws_json_value *array, size_t index);
+
+/**
+ * Returns the number of items in the array aws_json_value.
+ * @param array The array aws_json_value.
+ * @return The number of items in the array_json_value.
+ */
+AWS_COMMON_API
+size_t aws_json_get_array_size(const struct aws_json_value *array);
+
+/**
+ * Removes the aws_json_value at the given index in the array aws_json_value.
+ * @param array The array aws_json_value.
+ * @param index The index containing the aws_json_value you want to remove.
+ * @return AWS_OP_SUCCESS if the aws_json_value at the index was removed.
+ *          Will return AWS_OP_ERR if the array passed is invalid or if the index
+ *          passed is out of range.
+ */
+AWS_COMMON_API
+int aws_json_value_remove_array_element(struct aws_json_value *array, size_t index);
+// ====================
+
+// ====================
+// Checks
+
+/**
+ * Checks if the aws_json_value is a string.
+ * @param value The aws_json_value to check.
+ * @return True if the aws_json_value is a string aws_json_value, otherwise false.
+ */
+AWS_COMMON_API
+bool aws_json_value_is_string(const struct aws_json_value *value);
+
+/**
+ * Checks if the aws_json_value is a number.
+ * @param value The aws_json_value to check.
+ * @return True if the aws_json_value is a number aws_json_value, otherwise false.
+ */
+AWS_COMMON_API
+bool aws_json_value_is_number(const struct aws_json_value *value);
+
+/**
+ * Checks if the aws_json_value is a array.
+ * @param value The aws_json_value to check.
+ * @return True if the aws_json_value is a array aws_json_value, otherwise false.
+ */
+AWS_COMMON_API
+bool aws_json_value_is_array(const struct aws_json_value *value);
+
+/**
+ * Checks if the aws_json_value is a boolean.
+ * @param value The aws_json_value to check.
+ * @return True if the aws_json_value is a boolean aws_json_value, otherwise false.
+ */
+AWS_COMMON_API
+bool aws_json_value_is_boolean(const struct aws_json_value *value);
+
+/**
+ * Checks if the aws_json_value is a null aws_json_value.
+ * @param value The aws_json_value to check.
+ * @return True if the aws_json_value is a null aws_json_value, otherwise false.
+ */
+AWS_COMMON_API
+bool aws_json_value_is_null(const struct aws_json_value *value);
+
+/**
+ * Checks if the aws_json_value is a object aws_json_value.
+ * @param value The aws_json_value to check.
+ * @return True if the aws_json_value is a object aws_json_value, otherwise false.
+ */
+AWS_COMMON_API
+bool aws_json_value_is_object(const struct aws_json_value *value);
+// ====================
+
+// ====================
+// Memory Management
+
+/**
+ * Initializes the JSON module for use.
+ * @param allocator The allocator to use for creating aws_json_value structs.
+ */
+AWS_COMMON_API
+void aws_json_module_init(struct aws_allocator *allocator);
+
+/**
+ * Cleans up the JSON module. Should be called when finished using the module.
+ */
+AWS_COMMON_API
+void aws_json_module_cleanup(void);
+
+/**
+ * Removes the aws_json_value from memory. If the aws_json_value is a object or array, it will also destroy
+ * attached aws_json_values as well.
+ *
+ * For example, if you called "aws_json_array_add(b, a)" to add an object "a" to an array "b", if you call
+ * "aws_json_destroy(b)" then it will also free "a" automatically. All children/attached aws_json_values are freed
+ * when the parent/root aws_json_value is destroyed.
+ * @param value The aws_json_value to destroy.
+ */
+AWS_COMMON_API
+void aws_json_value_destroy(struct aws_json_value *value);
+// ====================
+
+// ====================
+// Utility
+
+/**
+ * Appends a unformatted JSON string representation of the aws_json_value into the passed byte buffer.
+ * The byte buffer is expected to be already initialized so the function can append the JSON into it.
+ *
+ * Note: The byte buffer will automatically have its size extended if the JSON string is over the byte
+ * buffer capacity AND the byte buffer has an allocator associated with it. If the byte buffer does not
+ * have an allocator associated and the JSON string is over capacity, AWS_OP_ERR will be returned.
+ *
+ * Note: When you are finished with the aws_byte_buf, you must call "aws_byte_buf_clean_up_secure" to free
+ * the memory used, as it will NOT be called automatically.
+ * @param value The aws_json_value to format.
+ * @param output The destination for the JSON string
+ * @return AWS_OP_SUCCESS if the JSON string was allocated to output without any errors
+ *      Will return AWS_OP_ERR if the value passed is not an aws_json_value or if there
+ *      was an error appending the JSON into the byte buffer.
+ */
+AWS_COMMON_API
+int aws_byte_buf_append_json_string(const struct aws_json_value *value, struct aws_byte_buf *output);
+
+/**
+ * Appends a formatted JSON string representation of the aws_json_value into the passed byte buffer.
+ * The byte buffer is expected to already be initialized so the function can append the JSON into it.
+ *
+ * Note: The byte buffer will automatically have its size extended if the JSON string is over the byte
+ * buffer capacity AND the byte buffer has an allocator associated with it. If the byte buffer does not
+ * have an allocator associated and the JSON string is over capacity, AWS_OP_ERR will be returned.
+ *
+ * Note: When you are finished with the aws_byte_buf, you must call "aws_byte_buf_clean_up_secure" to free
+ * the memory used, as it will NOT be called automatically.
+ * @param value The aws_json_value to format.
+ * @param output The destination for the JSON string
+ * @return AWS_OP_SUCCESS if the JSON string was allocated to output without any errors
+ *      Will return AWS_ERROR_INVALID_ARGUMENT if the value passed is not an aws_json_value or if there
+ *      aws an error appending the JSON into the byte buffer.
+ */
+AWS_COMMON_API
+int aws_byte_buf_append_json_string_formatted(const struct aws_json_value *value, struct aws_byte_buf *output);
+
+/**
+ * Parses the JSON string and returns a aws_json_value containing the root of the JSON.
+ * @param allocator The allocator used to create the value
+ * @param string The string containing the JSON.
+ * @return The root aws_json_value of the JSON.
+ */
+AWS_COMMON_API
+struct aws_json_value *aws_json_value_new_from_string(struct aws_allocator *allocator, struct aws_byte_cursor string);
+// ====================
+
+#endif // AWS_COMMON_JSON_H