Fix recursion counter check. Add control to override depth of nested … (#4953)

* Fix recursion counter check. Add control to override depth of nested objects.

* Change if-condition to `>=`

docs/source/Building.md

@@ -80,6 +80,14 @@ target_link_libraries(own_project_target PRIVATE flatbuffers)
 When build your project the `flatbuffers` library will be compiled and linked 
 to a target as part of your project.
 
+#### Override default depth limit of nested objects
+To override [the depth limit of recursion](@ref flatbuffers_guide_use_cpp), 
+add this directive:
+```cmake
+set(FLATBUFFERS_MAX_PARSING_DEPTH 16)
+```
+to `CMakeLists.txt` file before `add_subdirectory(${FLATBUFFERS_SRC_DIR})` line.
+
 #### For Google Play apps
 
 For applications on Google Play that integrate this library, usage is tracked.

docs/source/CppUsage.md

@@ -495,4 +495,13 @@ needed to use unions.
 
 To use scalars, simply wrap them in a struct.
 
+## Depth limit of nested objects and stack-overflow control
+The parser of Flatbuffers schema or json-files is kind of recursive parser.
+To avoid stack-overflow problem the parser has a built-in limiter of recursion depth.
+Number of nested declarations in a schema or number of nested json-objects is limited. 
+By default, this depth limit set to `64`.
+It is possible to override this limit with `FLATBUFFERS_MAX_PARSING_DEPTH` definition.
+This definition can be helpful for testing purposes or embedded applications.
+For details see [build](@ref flatbuffers_guide_building) of CMake-based projects.
+
 <br>