1 files changed, 47 insertions, 0 deletions
diff --git a/misc/lldb_yjit.py b/misc/lldb_yjit.py
new file mode 100644
index 0000000000..cc37b990ea
--- /dev/null
+++ b/misc/lldb_yjit.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+#coding: utf-8
+#
+# Usage: run `command script import -r misc/lldb_yjit.py` on LLDB
+#
+
+from __future__ import print_function
+import lldb
+import os
+import shlex
+
+def list_comments(debugger, command, result, internal_dict):
+    target = debugger.GetSelectedTarget()
+    process = target.GetProcess()
+    thread = process.GetSelectedThread()
+    frame = thread.GetSelectedFrame()
+
+    # Get the different types we need
+    rb_darray_meta_t = target.FindFirstType("rb_darray_meta_t")
+    codeblock_t = target.FindFirstType("codeblock_t")
+    yjit_comment = target.FindFirstType("yjit_comment")
+
+    # Get the global variables we need
+    comments = target.FindFirstGlobalVariable("yjit_code_comments")
+    cb = target.FindFirstGlobalVariable("cb").Cast(codeblock_t.GetPointerType())
+
+    # Get the address of the memory block we're using
+    mem_addr = cb.GetChildMemberWithName("mem_block").GetValueAsUnsigned()
+
+    # Find the size of the darray comment list
+    meta = comments.Cast(rb_darray_meta_t.GetPointerType())
+    size = meta.GetChildMemberWithName("size").GetValueAsUnsigned()
+
+    # Get the address of the block following the metadata header
+    t_offset = comments.GetValueAsUnsigned() + rb_darray_meta_t.GetByteSize()
+
+    # Loop through each comment and print
+    for t in range(0, size):
+        addr = lldb.SBAddress(t_offset + (t * yjit_comment.GetByteSize()), target)
+        comment = target.CreateValueFromAddress("yjit_comment", addr, yjit_comment)
+        string = comment.GetChildMemberWithName("comment")
+        comment_offset = mem_addr + comment.GetChildMemberWithName("offset").GetValueAsUnsigned()
+        print("%0#x %s" % (comment_offset, string.GetSummary()), file = result)
+
+
+def __lldb_init_module(debugger, internal_dict):
+    debugger.HandleCommand("command script add -f lldb_yjit.list_comments lc")