ruby/ujit.rb
Aaron Patterson e427fdff0a Directly link libcapstone for easier development
This lets us use libcapstone directly from miniruby so we don't need a
Ruby Gem to to dev work.

Example usage:

```ruby
def foo(x)
  if x < 1
    "wow"
  else
    "neat"
  end
end

iseq = RubyVM::InstructionSequence.of(method(:foo))
puts UJIT.disasm(iseq)
100.times { foo 1 }
puts UJIT.disasm(iseq)
```

Then in the terminal

```
$ ./miniruby test.rb

== disasm: #<ISeq:foo@test.rb:1 (1,0)-(7,3)> (catch: FALSE)
local table (size: 1, argc: 1 [opts: 0, rest: -1, post: 0, block: -1, kw: -1@-1, kwrest: -1])
[ 1] x@0<Arg>
0000 getlocal_WC_0                          x@0                       (   2)[LiCa]
0002 putobject_INT2FIX_1_
0003 opt_lt                                 <calldata!mid:<, argc:1, ARGS_SIMPLE>
0005 branchunless                           10
0007 putstring                              "wow"                     (   3)[Li]
0009 leave                                                            (   7)[Re]
0010 putstring                              "neat"                    (   5)[Li]
0012 leave                                                            (   7)[Re]

== ISEQ RANGE: 10 -> 10 ========================================================
        0x0:    movabs  rax, 0x7fe816e2d1a0
        0xa:    mov     qword ptr [rdi], rax
        0xd:    mov     r8, rax
        0x10:   mov     r9, rax
        0x13:   mov     r11, r12
        0x16:   jmp     qword ptr [rax]
== ISEQ RANGE: 0 -> 7 ==========================================================
        0x0:    mov     rax, qword ptr [rdi + 0x20]
        0x4:    mov     rax, qword ptr [rax - 0x18]
        0x8:    mov     qword ptr [rdx], rax
        0xb:    mov     qword ptr [rdx + 8], 3
        0x13:   movabs  rax, 0x7fe817808200
        0x1d:   test    byte ptr [rax + 0x3e6], 1
        0x24:   jne     0x3ffff7b
        0x2a:   test    byte ptr [rdx], 1
        0x2d:   je      0x3ffff7b
        0x33:   test    byte ptr [rdx + 8], 1
        0x37:   je      0x3ffff7b
        0x3d:   mov     rax, qword ptr [rdx]
        0x40:   cmp     rax, qword ptr [rdx + 8]
        0x44:   movabs  rax, 0
        0x4e:   movabs  rcx, 0x14
        0x58:   cmovl   rax, rcx
        0x5c:   mov     qword ptr [rdx], rax
        0x5f:   test    qword ptr [rdx], -9
        0x66:   jne     0x3ffffd5
```

Make sure to `brew install pkg-config capstone`
2021-10-20 18:19:27 -04:00

31 lines
686 B
Ruby

module UJIT
def omg
end
def self.disasm(iseq)
blocks = UJIT.blocks_for(iseq)
return if blocks.empty?
str = ""
cs = UJIT::Disasm.open(UJIT::Disasm::ARCH_X86, UJIT::Disasm::MODE_64)
str << iseq.disasm
str << "\n"
blocks.sort_by(&:address).reverse.each do |block|
str << "== ISEQ RANGE: #{block.iseq_start_index} -> #{block.iseq_end_index} ".ljust(80, "=")
str << "\n"
cs.disasm(block.code, 0).each do |i|
str << sprintf(
"\t0x%<address>x:\t%<instruction>s\t%<details>s\n",
address: i.address,
instruction: i.mnemonic,
details: i.op_str
)
end
end
str
end
end