add a helper script for ujit disasm

misc/ujit_disasm.rb

@@ -0,0 +1,34 @@
+begin
+require "crabstone"
+require "stringio"
+
+module UJIT
+  def self.disasm(iseq)
+    blocks = UJIT.blocks_for(iseq)
+    return if blocks.empty?
+
+    io = StringIO.new
+
+    cs = Crabstone::Disassembler.new(Crabstone::ARCH_X86, Crabstone::MODE_64)
+
+    io.puts iseq.disasm
+
+    blocks.sort_by(&:address).reverse.each do |block|
+      io.puts "== ISEQ RANGE: #{block.iseq_start_index} -> #{block.iseq_end_index} ".ljust(80, "=")
+      cs.disasm(block.code, 0).each do |i|
+        io.printf(
+          "\t0x%<address>x:\t%<instruction>s\t%<details>s\n",
+          address: i.address,
+          instruction: i.mnemonic,
+          details: i.op_str
+        )
+      end
+    end
+    io.string
+  end
+end
+rescue
+  puts "Please install crabstone like this:"
+  puts "  $ brew install capstone"
+  puts "  $ gem install capstone"
+end