Add `full` option to `ObjectSpace.dump_all`

The `full` option includes all slots (even `T_NONE`) in the JSON output.
This is to help with debugging heap fragmentation.

Here is an example usage:

```ruby
File.open('heap.json', 'w') do |f|
  ObjectSpace.dump_all(output: f, full: true)
end
```

The `heap.json` file contains all slots, including empty slots.

[Feature #13001] [ruby-core:78468]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57260 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 17 insertions, 3 deletions

diff --git a/ext/objspace/objspace_dump.c b/ext/objspace/objspace_dump.c
index 127d33283a..9c2055d6d8 100644
--- a/ext/objspace/objspace_dump.c
+++ b/ext/objspace/objspace_dump.c
@@ -21,6 +21,7 @@
 #include "objspace.h"
 
 static VALUE sym_output, sym_stdout, sym_string, sym_file;
+static VALUE sym_full;
 
 struct dump_config {
     VALUE type;
@@ -31,6 +32,7 @@ struct dump_config {
     VALUE cur_obj;
     VALUE cur_obj_klass;
     size_t cur_obj_references;
+    int full_heap;
 };
 
 PRINTF_ARGS(static void dump_append(struct dump_config *, const char *, ...), 2, 3);
@@ -219,6 +221,10 @@ dump_object(VALUE obj, struct dump_config *dc)
 	dump_append(dc, ", \"frozen\":true");
 
     switch (BUILTIN_TYPE(obj)) {
+      case T_NONE:
+	  dump_append(dc, "}\n");
+	  return;
+
       case T_NODE:
 	dump_append(dc, ", \"node_type\":\"%s\"", ruby_node_name(nd_type(obj)));
 	break;
@@ -318,10 +324,11 @@ dump_object(VALUE obj, struct dump_config *dc)
 static int
 heap_i(void *vstart, void *vend, size_t stride, void *data)
 {
+    struct dump_config *dc = (struct dump_config *)data;
     VALUE v = (VALUE)vstart;
     for (; v != (VALUE)vend; v += stride) {
-	if (RBASIC(v)->flags)
-	    dump_object(v, data);
+	if (dc->full_heap || RBASIC(v)->flags)
+	    dump_object(v, dc);
     }
     return 0;
 }
@@ -347,9 +354,15 @@ dump_output(struct dump_config *dc, VALUE opts, VALUE output, const char *filena
 {
     VALUE tmp;
 
-    if (RTEST(opts))
+    dc->full_heap = 0;
+
+    if (RTEST(opts)) {
 	output = rb_hash_aref(opts, sym_output);
 
+	if (Qtrue == rb_hash_lookup2(opts, sym_full, Qfalse))
+	    dc->full_heap = 1;
+    }
+
     if (output == sym_stdout) {
 	dc->stream = stdout;
 	dc->string = Qnil;
@@ -474,6 +487,7 @@ Init_objspace_dump(VALUE rb_mObjSpace)
     sym_stdout = ID2SYM(rb_intern("stdout"));
     sym_string = ID2SYM(rb_intern("string"));
     sym_file   = ID2SYM(rb_intern("file"));
+    sym_full   = ID2SYM(rb_intern("full"));
 
     /* force create static IDs */
     rb_obj_gc_flags(rb_mObjSpace, 0, 0);