include/ruby/debug.h: add doxygen

Must not be a bad idea to improve documents. [ci skip]

2 files changed, 548 insertions, 37 deletions

diff --git a/include/ruby/debug.h b/include/ruby/debug.h
index 16891e8458..c88da9c43d 100644
--- a/include/ruby/debug.h
+++ b/include/ruby/debug.h
@@ -10,6 +10,8 @@
  *             modify this file, provided that  the conditions mentioned in the
  *             file COPYING are met.  Consult the file for details.
  */
+#include "ruby/internal/attr/nonnull.h"
+#include "ruby/internal/attr/returns_nonnull.h"
 #include "ruby/internal/dllexport.h"
 #include "ruby/internal/event.h"
 #include "ruby/internal/value.h"
@@ -19,74 +21,611 @@ RBIMPL_SYMBOL_EXPORT_BEGIN()
 /* Note: This file contains experimental APIs. */
 /* APIs can be replaced at Ruby 2.0.1 or later */
 
+/**
+ * @name Frame-profiling APIs
+ *
+ * @{
+ */
 
-/* profile frames APIs */
+RBIMPL_ATTR_NONNULL((3))
+/**
+ * Queries mysterious "frame"s of the given range.
+ *
+ * The returned values are opaque backtrace  pointers, which you are allowed to
+ * issue a very  limited set of operations listed below.   Don't call arbitrary
+ * ruby methods.
+ *
+ * @param[in]   start  Start position (0 means the topmost).
+ * @param[in]   limit  Number objects of `buff`.
+ * @param[out]  buff   Return buffer.
+ * @param[out]  lines  Return buffer.
+ * @return      Number of objects filled into `buff`.
+ * @post        `buff` is filled with backtrace pointers.
+ * @post        `lines` is filled with `__LINE__` of each backtraces.
+ *
+ * @internal
+ *
+ * @shyouhei  doesn't  like  this  abuse  of  ::VALUE.   It  should  have  been
+ * `const struct rb_callable_method_entry_struct *`.
+ */
 int rb_profile_frames(int start, int limit, VALUE *buff, int *lines);
+
+/**
+ * Queries the path of the passed backtrace.
+ *
+ * @param[in]  frame      What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil  The frame is implemented in C etc.
+ * @retval     otherwise  Where `frame` is running.
+ */
 VALUE rb_profile_frame_path(VALUE frame);
+
+/**
+ * Identical  to  rb_profile_frame_path(),  except   it  tries  to  expand  the
+ * returning  path.   In case  the  path  is  `require`-d from  something  else
+ * rb_profile_frame_path() can return relative paths.   This one tries to avoid
+ * that.
+ *
+ * @param[in]  frame      What rb_profile_frames() returned.
+ * @retval     "<cfunc>"  The frame is in C.
+ * @retval     RUBY_Qnil  Can't infer real path (inside of `eval` etc.).
+ * @retval     otherwise  Where `frame` is running.
+ */
 VALUE rb_profile_frame_absolute_path(VALUE frame);
+
+/**
+ * Queries human-readable "label" string.  This is `"<main>"` for the toplevel,
+ * `"<compiled>"` for evaluated  ones, method name for methods,  class name for
+ * classes.
+ *
+ * @param[in]  frame         What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil     Can't infer the label (C etc.).
+ * @retval     "<main>"      The frame is global toplevel.
+ * @retval     "<compiled>"  The frame is dynamic.
+ * @retval     otherwise     Label of the frame.
+ */
 VALUE rb_profile_frame_label(VALUE frame);
+
+/**
+ * Identical  to rb_profile_frame_label(),  except  it does  not "qualify"  the
+ * result.  Consider the following backtrace:
+ *
+ * ```ruby
+ * def bar
+ *   caller_locations
+ * end
+ *
+ * def foo
+ *   [1].map { bar }.first
+ * end
+ *
+ * obj = foo.first
+ * obj.label      # => "block in foo"
+ * obj.base_label # => "foo"
+ * ```
+ *
+ * @param[in]  frame         What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil     Can't infer the label (C etc.).
+ * @retval     "<main>"      The frame is global toplevel.
+ * @retval     "<compiled>"  The frame is dynamic.
+ * @retval     otherwise     Base label of the frame.
+ */
 VALUE rb_profile_frame_base_label(VALUE frame);
+
+/**
+ * Identical to rb_profile_frame_label(), except it returns a qualified result.
+ *
+ * @param[in]  frame         What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil     Can't infer the label (C etc.).
+ * @retval     "<main>"      The frame is global toplevel.
+ * @retval     "<compiled>"  The frame is dynamic.
+ * @retval     otherwise     Qualified label of the frame.
+ *
+ * @internal
+ *
+ * As  of writing  there is  no way  to obtain  this return  value from  a Ruby
+ * script.  This may change  in future (it took 8 years  and still no progress,
+ * though).
+ */
 VALUE rb_profile_frame_full_label(VALUE frame);
+
+/**
+ * Queries the first  line of the method  of the passed frame  pointer.  Can be
+ * handy when for instance a debugger want to display the frame in question.
+ *
+ * @param[in]  frame      What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil  Can't infer the line (C etc.).
+ * @retval     otherwise  Line number of the method in question.
+ */
 VALUE rb_profile_frame_first_lineno(VALUE frame);
+
+/**
+ * Queries the class path of the method that the passed frame represents.
+ *
+ * @param[in]  frame      What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil  Can't infer the class (global toplevel etc.).
+ * @retval     otherwise  Class path as in rb_class_path().
+ */
 VALUE rb_profile_frame_classpath(VALUE frame);
+
+/**
+ * Queries if the method of the passed frame is a singleton class.
+ *
+ * @param[in]  frame        What rb_profile_frames() returned.
+ * @retval     RUBY_Qtrue   It is a singleton method.
+ * @retval     RUBY_Qfalse  Otherwise (normal method/non-method).
+ */
 VALUE rb_profile_frame_singleton_method_p(VALUE frame);
+
+/**
+ * Queries the name of the method of the passed frame.
+ *
+ * @param[in]  frame      What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil  The frame in question is not a method.
+ * @retval     otherwise  Name of the method of the frame.
+ */
 VALUE rb_profile_frame_method_name(VALUE frame);
+
+/**
+ * Identical  to  rb_profile_frame_method_name(),  except  it  "qualifies"  the
+ * return value with its defining class.
+ *
+ * @param[in]  frame      What rb_profile_frames() returned.
+ * @retval     RUBY_Qnil  The frame in question is not a method.
+ * @retval     otherwise  Qualified name of the method of the frame.
+ */
 VALUE rb_profile_frame_qualified_method_name(VALUE frame);
 
-/* debug inspector APIs */
+/** @} */
+
+/**
+ * @name Debug inspector APIs
+ *
+ * @{
+ */
+
+/** Opaque struct representing a debug inspector. */
 typedef struct rb_debug_inspector_struct rb_debug_inspector_t;
-typedef VALUE (*rb_debug_inspector_func_t)(const rb_debug_inspector_t *, void *);
 
+/**
+ * Type  of   the  callback   function  passed   to  rb_debug_inspector_open().
+ * Inspection  shall happen  only inside  of  them.  The  passed pointers  gets
+ * invalidated once after the callback returns.
+ *
+ * @param[in]      dc    A debug context.
+ * @param[in,out]  data  What was passed to rb_debug_inspector_open().
+ * @return         What would be the return value of rb_debug_inspector_open().
+ */
+typedef VALUE (*rb_debug_inspector_func_t)(const rb_debug_inspector_t *dc, void *data);
+
+/**
+ * Prepares, executes, then cleans up a debug session.
+ *
+ * @param[in]      func  A callback to run inside of a debug session.
+ * @param[in,out]  data  Passed as-is to `func`.
+ * @return         What was returned from `func`.
+ */
 VALUE rb_debug_inspector_open(rb_debug_inspector_func_t func, void *data);
+
+/**
+ * Queries the current receiver of the passed context's upper frame.
+ *
+ * @param[in]  dc           A debug context.
+ * @param[in]  index        Index of the frame from top to bottom.
+ * @exception  rb_eArgError `index` out of range.
+ * @return     The current receiver at `index`-th frame.
+ */
 VALUE rb_debug_inspector_frame_self_get(const rb_debug_inspector_t *dc, long index);
+
+/**
+ * Queries the current class of the passed context's upper frame.
+ *
+ * @param[in]  dc           A debug context.
+ * @param[in]  index        Index of the frame from top to bottom.
+ * @exception  rb_eArgError `index` out of range.
+ * @return     The current class at `index`-th frame.
+ */
 VALUE rb_debug_inspector_frame_class_get(const rb_debug_inspector_t *dc, long index);
+
+/**
+ * Queries the binding of the passed context's upper frame.
+ *
+ * @param[in]  dc           A debug context.
+ * @param[in]  index        Index of the frame from top to bottom.
+ * @exception  rb_eArgError `index` out of range.
+ * @return     The binding at `index`-th frame.
+ */
 VALUE rb_debug_inspector_frame_binding_get(const rb_debug_inspector_t *dc, long index);
+
+/**
+ * Queries the instruction sequence of the passed context's upper frame.
+ *
+ * @param[in]  dc           A debug context.
+ * @param[in]  index        Index of the frame from top to bottom.
+ * @exception  rb_eArgError `index` out of range.
+ * @retval     RUBY_Qnil    `index`-th frame is not in Ruby (C etc.).
+ * @retval     otherwise    An instance  of `RubyVM::InstructionSequence` which
+ *                          represents the  instruction sequence  at `index`-th
+ *                          frame.
+ */
 VALUE rb_debug_inspector_frame_iseq_get(const rb_debug_inspector_t *dc, long index);
+
+/**
+ * Queries  the backtrace  object  of the  context.   This is  as  if you  call
+ * `caller_locations` at the point of debugger.
+ *
+ * @param[in]  dc  A debug context.
+ * @return     An array  of `Thread::Backtrace::Location` which  represents the
+ *             current point of execution at `dc`.
+
+ */
 VALUE rb_debug_inspector_backtrace_locations(const rb_debug_inspector_t *dc);
 
-/* Old style set_trace_func APIs */
+/** @} */
+
+/**
+ * @name Old style set_trace_func APIs
+ *
+ * @{
+ */
 
 /* duplicated def of include/ruby/ruby.h */
-void rb_add_event_hook(rb_event_hook_func_t func, rb_event_flag_t events, VALUE data);
-int rb_remove_event_hook(rb_event_hook_func_t func);
+#include "ruby/internal/event.h"
 
+/**
+ * Identical to  rb_remove_event_hook(), except it additionally  takes the data
+ * argument.  This extra  argument is the same as  that of rb_add_event_hook(),
+ * and this function removes the hook which matches both arguments at once.
+ *
+ * @param[in]  func  A callback.
+ * @param[in]  data  What to be passed to `func`.
+ * @return     Number of deleted event hooks.
+ * @note       As  multiple  events can  share  the  same  `func` it  is  quite
+ *             possible for the return value to become more than one.
+ */
 int rb_remove_event_hook_with_data(rb_event_hook_func_t func, VALUE data);
+
+/**
+ * Identical to rb_add_event_hook(), except its effect is limited to the passed
+ * thread.  Other threads are not affected by this.
+ *
+ * @param[in]  thval          An instance of ::rb_cThread.
+ * @param[in]  func           A callback.
+ * @param[in]  events         A set of events that `func` should run.
+ * @param[in]  data           Passed as-is to `func`.
+ * @exception  rb_eTypeError  `thval` is not a thread.
+ */
 void rb_thread_add_event_hook(VALUE thval, rb_event_hook_func_t func, rb_event_flag_t events, VALUE data);
+
+/**
+ * Identical to  rb_remove_event_hook(), except it additionally  takes a thread
+ * argument.     This   extra    argument   is    the   same    as   that    of
+ * rb_thread_add_event_hook(), and this function removes the hook which matches
+ * both arguments at once.
+ *
+ * @param[in]  thval          An instance of ::rb_cThread.
+ * @param[in]  func           A callback.
+ * @exception  rb_eTypeError  `thval` is not a thread.
+ * @return     Number of deleted event hooks.
+ * @note       As  multiple  events can  share  the  same  `func` it  is  quite
+ *             possible for the return value to become more than one.
+ */
 int rb_thread_remove_event_hook(VALUE thval, rb_event_hook_func_t func);
+
+/**
+ * Identical to rb_thread_remove_event_hook(), except it additionally takes the
+ * data  argument.    It  can  also   be  seen   as  a  routine   identical  to
+ * rb_remove_event_hook_with_data(), except  it additionally takes  the thread.
+ * This function deletes hooks that satisfy all three criteria.
+ *
+ * @param[in]  thval          An instance of ::rb_cThread.
+ * @param[in]  func           A callback.
+ * @param[in]  data           What to be passed to `func`.
+ * @exception  rb_eTypeError  `thval` is not a thread.
+ * @return     Number of deleted event hooks.
+ * @note       As  multiple  events can  share  the  same  `func` it  is  quite
+ *             possible for the return value to become more than one.
+ */
 int rb_thread_remove_event_hook_with_data(VALUE thval, rb_event_hook_func_t func, VALUE data);
 
-/* TracePoint APIs */
+/** @} */
 
+/**
+ * @name TracePoint APIs
+ *
+ * @{
+ */
+
+/**
+ * Creates a  tracepoint by  registering a  callback function  for one  or more
+ * tracepoint   events.  Once   the  tracepoint   is  created,   you  can   use
+ * rb_tracepoint_enable to enable the tracepoint.
+ *
+ * @param[in]      target_thread_not_supported_yet  Meant   for   picking   the
+ *                         thread  in which  the tracepoint  is to  be created.
+ *                         However,   current    implementation   ignore   this
+ *                         parameter,  tracepoint is  created for  all threads.
+ *                         Simply specify Qnil.
+ * @param[in]      events  Event(s) to listen to.
+ * @param[in]      func    A callback function.
+ * @param[in,out]  data    Void  pointer that  will be  passed to  the callback
+ *                         function.
+ *
+ * When the callback function is called, it will be passed 2 parameters:
+ *   1. `VALUE  tpval` -  the TracePoint  object from which  trace args  can be
+ *      extracted.
+ *   1. `void  *data` -  A void  pointer which  helps to  share scope  with the
+ *      callback function.
+ *
+ * It is important to note that you cannot register callbacks for normal events
+ * and internal events simultaneously because  they are different purpose.  You
+ * can use  any Ruby APIs  (calling methods and so  on) on normal  event hooks.
+ * However, in  internal events,  you can  not use any  Ruby APIs  (even object
+ * creations).   This is  why we  can't specify  internal events  by TracePoint
+ * directly.  Limitations are MRI version specific.
+ *
+ * Example:
+ *
+ * ```CXX
+ * rb_tracepoint_new(
+ *     Qnil,
+ *     RUBY_INTERNAL_EVENT_NEWOBJ | RUBY_INTERNAL_EVENT_FREEOBJ,
+ *     obj_event_i,
+ *     data);
+ * ```
+ *
+ * In this  example, a callback  function `obj_event_i` will be  registered for
+ * internal           events          #RUBY_INTERNAL_EVENT_NEWOBJ           and
+ * #RUBY_INTERNAL_EVENT_FREEOBJ.
+ */
 VALUE rb_tracepoint_new(VALUE target_thread_not_supported_yet, rb_event_flag_t events, void (*func)(VALUE, void *), void *data);
+
+/**
+ * Starts (enables) trace(s) defined by the passed object.  A TracePoint object
+ * does not immediately  take effect on creation.  You have  to explicitly call
+ * this API.
+ *
+ * @param[in]  tpval         An instance of TracePoint.
+ * @exception  rb_eArgError  A trace is already running.
+ * @return     Undefined value.  Forget this.  It should have returned `void`.
+ * @post       Trace(s) defined by `tpval` start.
+ */
 VALUE rb_tracepoint_enable(VALUE tpval);
+
+/**
+ * Stops (disables) an already running instance of TracePoint.
+ *
+ * @param[in]  tpval  An instance of TracePoint.
+ * @return     Undefined value.  Forget this.  It should have returned `void`.
+ * @post       Trace(s) defined by `tpval` stop.
+ */
 VALUE rb_tracepoint_disable(VALUE tpval);
+
+/**
+ * Queries if the passed TracePoint is up and running.
+ *
+ * @param[in]  tpval        An instance of TracePoint.
+ * @retval     RUBY_Qtrue   It is.
+ * @retval     RUBY_Qfalse  It isn't.
+ */
 VALUE rb_tracepoint_enabled_p(VALUE tpval);
 
+/**
+ * Type  that  represents  a  specific  trace  event.   Roughly  resembles  the
+ * tracepoint object that is passed to the block of `TracePoint.new`:
+ *
+ * ```ruby
+ * TracePoint.new(*events) do |obj|
+ *   ...                    # ^^^^^  Resembles this object.
+ * end
+ * ```
+ */
 typedef struct rb_trace_arg_struct rb_trace_arg_t;
+
+RBIMPL_ATTR_RETURNS_NONNULL()
+/**
+ * Queries the current event of the passed tracepoint.
+ *
+ * @param[in]  tpval             An instance of TracePoint.
+ * @exception  rb_eRuntimeError  `tpval` is disabled.
+ * @return     The current event.
+ *
+ * @internal
+ *
+ * `tpval` is  a fake.  There is  only one instance of  ::rb_trace_arg_t at one
+ * time.  This function just returns that global variable.
+ */
 rb_trace_arg_t *rb_tracearg_from_tracepoint(VALUE tpval);
 
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the event of the passed trace.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @return     Its event.
+ */
 rb_event_flag_t rb_tracearg_event_flag(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Identical to  rb_tracearg_event_flag(), except  it returns  the name  of the
+ * event in Ruby's symbol.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @return     Its event, in Ruby level Symbol object.
+ */
 VALUE rb_tracearg_event(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the line of the point where the trace is at.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     0          The trace is not at Ruby frame.
+ * @return     otherwise  Its line number.
+ */
 VALUE rb_tracearg_lineno(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the file name of the point where the trace is at.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     RUBY_Qnil  The trace is not at Ruby frame.
+ * @retval     otherwise  Its path.
+ */
 VALUE rb_tracearg_path(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the method name of the point where the trace is at.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     RUBY_Qnil  There is no method.
+ * @retval     otherwise  Its method name, in Ruby level Symbol.
+ */
 VALUE rb_tracearg_method_id(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Identical  to  rb_tracearg_method_id(), except  it  returns  callee id  like
+ * rb_frame_callee().
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     RUBY_Qnil  There is no method.
+ * @retval     otherwise  Its method name, in Ruby level Symbol.
+ */
 VALUE rb_tracearg_callee_id(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the class that defines the method that the passed trace is at.  This
+ * can be different from the class of rb_tracearg_self()'s return value because
+ * of inheritance(s).
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     RUBY_Qnil  There is no method.
+ * @retval     otherwise  Its method's class.
+ */
 VALUE rb_tracearg_defined_class(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Creates a binding object of the point where the trace is at.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @retval     RUBY_Qnil  The point has no binding.
+ * @retval     otherwise  Its binding.
+ *
+ * @internal
+ *
+ * @shyouhei  has  no  idea  on  which situation  shall  this  function  return
+ * ::RUBY_Qnil.
+ */
 VALUE rb_tracearg_binding(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the receiver of the point trace is at.
+ *
+ * @param[in]  trace_arg  A trace instance.
+ * @return     Its receiver.
+ */
 VALUE rb_tracearg_self(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the return value that the trace represents.
+ *
+ * @param[in]  trace_arg         A trace instance.
+ * @exception  rb_eRuntimeError  The tracing event is not return-related.
+ * @return     The return value.
+ */
 VALUE rb_tracearg_return_value(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the raised exception that the trace represents.
+ *
+ * @param[in]  trace_arg         A trace instance.
+ * @exception  rb_eRuntimeError  The tracing event is not exception-related.
+ * @return     The raised exception.
+ */
 VALUE rb_tracearg_raised_exception(rb_trace_arg_t *trace_arg);
+
+RBIMPL_ATTR_NONNULL(())
+/**
+ * Queries the allocated/deallocated object that the trace represents.
+ *
+ * @param[in]  trace_arg         A trace instance.
+ * @exception  rb_eRuntimeError  The tracing event is not GC-related.
+ * @return     The allocated/deallocated object.
+ */
 VALUE rb_tracearg_object(rb_trace_arg_t *trace_arg);
 
+
+/** @} */
+
+/**
+ * @name Postponed Job API
+ *
+ * @{
+ */
+
 /*
  * Postponed Job API
  * rb_postponed_job_register and rb_postponed_job_register_one are
  * async-signal-safe and used via SIGPROF by the "stackprof" RubyGem
  */
+
+/**
+ * Type of postponed jobs.
+ *
+ * @param[in,out]  arg What was passed to rb_postponed_job_register().
+ */
 typedef void (*rb_postponed_job_func_t)(void *arg);
+
+/**
+ * Registers a postponed job.
+ *
+ * There  are situations  when running  a ruby  program is  not possible.   For
+ * instance when  a program is in  a signal handler; for  another instance when
+ * the GC  is busy.   On such situations  however, there might  be needs  to do
+ * something.  We cannot but defer such operations until we are 100% sure it is
+ * safe  to execute  them.   This  mechanism is  called  postponed jobs.   This
+ * function  registers a  new one.   The registered  job would  eventually gets
+ * executed.
+ *
+ * @param[in]      flags      (Unused) reserved for future extensions.
+ * @param[in]      func       Job body.
+ * @param[in,out]  data       Passed as-is to `func`.
+ * @retval         0          Postponed job buffer is full.  Failed.
+ * @retval         otherwise  Opaque return value.
+ * @post           The passed job is postponed.
+ */
 int rb_postponed_job_register(unsigned int flags, rb_postponed_job_func_t func, void *data);
+
+/**
+ * Identical to rb_postponed_job_register_one(),  except it additionally checks
+ * for  duplicated registration.   In case  the passed  job is  already in  the
+ * postponed job buffer this function does nothing.
+ *
+ * @param[in]      flags      (Unused) reserved for future extensions.
+ * @param[in]      func       Job body.
+ * @param[in,out]  data       Passed as-is to `func`.
+ * @retval         0          Postponed job buffer is full.  Failed.
+ * @retval         otherwise  Opaque return value.
+ */
 int rb_postponed_job_register_one(unsigned int flags, rb_postponed_job_func_t func, void *data);
 
+/** @} */
+
+/**
+ * @cond INTERNAL_MACRO
+ *
+ * Anything  after this  are  intentionally left  undocumented,  to honour  the
+ * comment below.
+ */
+
 /* undocumented advanced tracing APIs */
 
 typedef enum {
@@ -98,6 +637,8 @@ typedef enum {
 void rb_add_event_hook2(rb_event_hook_func_t func, rb_event_flag_t events, VALUE data, rb_event_hook_flag_t hook_flag);
 void rb_thread_add_event_hook2(VALUE thval, rb_event_hook_func_t func, rb_event_flag_t events, VALUE data, rb_event_hook_flag_t hook_flag);
 
+/** @endcond */
+
 RBIMPL_SYMBOL_EXPORT_END()
 
 #endif /* RUBY_DEBUG_H */
diff --git a/vm_trace.c b/vm_trace.c
index cec5e42e31..ac65e61db1 100644
--- a/vm_trace.c
+++ b/vm_trace.c
@@ -1384,36 +1384,6 @@ tracepoint_new(VALUE klass, rb_thread_t *target_th, rb_event_flag_t events, void
     return tpval;
 }
 
-/*
- * Creates a tracepoint by registering a callback function for one or more
- * tracepoint events. Once the tracepoint is created, you can use
- * rb_tracepoint_enable to enable the tracepoint.
- *
- * Parameters:
- *   1. VALUE target_thval - Meant for picking the thread in which the tracepoint
- *      is to be created. However, current implementation ignore this parameter,
- *      tracepoint is created for all threads. Simply specify Qnil.
- *   2. rb_event_flag_t events - Event(s) to listen to.
- *   3. void (*func)(VALUE, void *) - A callback function.
- *   4. void *data - Void pointer that will be passed to the callback function.
- *
- * When the callback function is called, it will be passed 2 parameters:
- *   1)VALUE tpval - the TracePoint object from which trace args can be extracted.
- *   2)void *data - A void pointer which helps to share scope with the callback function.
- *
- * It is important to note that you cannot register callbacks for normal events and internal events
- * simultaneously because they are different purpose.
- * You can use any Ruby APIs (calling methods and so on) on normal event hooks.
- * However, in internal events, you can not use any Ruby APIs (even object creations).
- * This is why we can't specify internal events by TracePoint directly.
- * Limitations are MRI version specific.
- *
- * Example:
- *   rb_tracepoint_new(Qnil, RUBY_INTERNAL_EVENT_NEWOBJ | RUBY_INTERNAL_EVENT_FREEOBJ, obj_event_i, data);
- *
- *   In this example, a callback function obj_event_i will be registered for
- *   internal events RUBY_INTERNAL_EVENT_NEWOBJ and RUBY_INTERNAL_EVENT_FREEOBJ.
- */
 VALUE
 rb_tracepoint_new(VALUE target_thval, rb_event_flag_t events, void (*func)(VALUE, void *), void *data)
 {