スーパールーキーに教わってたことのメモ
putsメソッドはrb_f_putsを呼んでいるので、そこでbreakpoitを仕込んでbacktrace取る。
% lldb `rbenv which ruby`
(lldb) target create "/opt/boxen/rbenv/versions/2.1.2/bin/ruby"
Current executable set to '/opt/boxen/rbenv/versions/2.1.2/bin/ruby' (x86_64).
(lldb) b rb_f_puts
Breakpoint 1: where = ruby`rb_f_puts, address = 0x0000000100069f60
(lldb) r -e 'puts 1'
Process 31982 launched: '/opt/boxen/rbenv/versions/2.1.2/bin/ruby' (x86_64)
Process 31982 stopped
* thread #1: tid = 0x12faced, 0x0000000100069f60 ruby`rb_f_puts, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x0000000100069f60 ruby`rb_f_puts
ruby`rb_f_puts:
-> 0x100069f60: pushq %rbp
0x100069f61: movq %rsp, %rbp
0x100069f64: pushq %r15
0x100069f66: pushq %r14
(lldb) bt
* thread #1: tid = 0x12faced, 0x0000000100069f60 ruby`rb_f_puts, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
* frame #0: 0x0000000100069f60 ruby`rb_f_puts
frame #1: 0x000000010016d07b ruby`vm_call_cfunc + 987
frame #2: 0x000000010016c9cb ruby`vm_call_method + 843
frame #3: 0x000000010015610c ruby`vm_exec_core + 10156
frame #4: 0x000000010016334f ruby`vm_exec + 127
frame #5: 0x0000000100164238 ruby`rb_iseq_eval_main + 392
frame #6: 0x000000010003ebb4 ruby`ruby_exec_internal + 148
frame #7: 0x000000010003eade ruby`ruby_run_node + 78
frame #8: 0x0000000100000d5f ruby`main + 79
frame #9: 0x00007fff8cb225fd libdyld.dylib`start + 1
frame #10: 0x00007fff8cb225fd libdyld.dylib`start + 1
(lldb) finish
1
Process 31982 stopped
* thread #1: tid = 0x12faced, 0x000000010016d07b ruby`vm_call_cfunc + 987, queue = 'com.apple.main-thread', stop reason = step out
frame #0: 0x000000010016d07b ruby`vm_call_cfunc + 987
ruby`vm_call_cfunc + 987:
-> 0x10016d07b: movq %rax, %r12
0x10016d07e: movq 0x20(%r13), %rax
0x10016d082: addq $0x50, %rax
0x10016d086: cmpq %rbx, %rax
