ObjectSpace.dump_all: dump shapes as well

I see several arguments in doing so.

First they use a non trivial amount of memory, so for various memory
profiling/mapping tools it is relevant to have visibility of the space
occupied by shapes.

Then, some pathological code can create a tons of shape, so it is
valuable to have a way to have a way to observe shapes without having
to compile Ruby with `SHAPE_DEBUG=1`.

And additionally it's likely much faster to dump then this way than
to use `RubyVM::Shape`.

There are however a few open questions:

- Shapes can't respect the `since:` argument. Not sure what to do when
  it is provided. Would probably make sense to not dump them.
- Maybe it would make more sense to have a separate `ObjectSpace.dump_shapes`?
- Maybe instead `dump_all` should take a `shapes: false` argument?

Additionally, `ObjectSpace.dump_shapes` is added for the use case of
debugging the evolution of the shape tree.

1 files changed, 8 insertions, 1 deletions

diff --git a/shape.h b/shape.h
index 96feae99fd..ddb870f5e7 100644
--- a/shape.h
+++ b/shape.h
@@ -124,7 +124,6 @@ bool rb_shape_root_shape_p(rb_shape_t* shape);
 rb_shape_t * rb_shape_get_root_shape(void);
 uint8_t rb_shape_id_num_bits(void);
 int32_t rb_shape_id_offset(void);
-unsigned int rb_shape_depth(rb_shape_t * shape);
 
 rb_shape_t* rb_shape_get_shape_by_id_without_assertion(shape_id_t shape_id);
 rb_shape_t * rb_shape_get_parent(rb_shape_t * shape);
@@ -184,4 +183,12 @@ bool rb_shape_set_shape_id(VALUE obj, shape_id_t shape_id);
 VALUE rb_obj_debug_shape(VALUE self, VALUE obj);
 VALUE rb_shape_flags_mask(void);
 
+RUBY_SYMBOL_EXPORT_BEGIN
+typedef void each_shape_callback(rb_shape_t * shape, void *data);
+void rb_shape_each_shape(each_shape_callback callback, void *data);
+size_t rb_shape_memsize(rb_shape_t *shape);
+size_t rb_shape_edges_count(rb_shape_t *shape);
+size_t rb_shape_depth(rb_shape_t *shape);
+RUBY_SYMBOL_EXPORT_END
+
 #endif