LLDB, a new debugger on Mac OS X

The LLVM team is working on a new debugger called lldb.

It compiles cleanly so you can give it a try if you have the devtools (including SVN client) installed on your machine.

Running it

You need to run the lldb-tool with the firewall disabled and as the superuser because it uses task_for_pid and in 10.6 this requires superuser privileges or code signing on the binary. Since the binary is not signed, you need to run it with superuser privileges, otherwise you will get an error like: "failed to send the qLaunchSuccess packet".

I run it this way:

sudo DYLD_FRAMEWORK_PATH=/Users/diciu/Programming/external/lldb/build/BuildAndIntegration/ ./build/BuildAndIntegration/lldb /tmp/a.out

LLDB vs GDB

LLDB	GDB
(lldb) breakpoint set -n main Breakpoint created: 1 Breakpoint by name: 'main' with 1 location; (lldb) r Launching '/private/tmp/a.out' (x86_64) (lldb) Process 50271 Stopped * thread #1: tid = 0x2c03, pc = 0x0000000100000edb, where = a.out`main + 11 at /private/tmp/test.c:14, stop reason = breakpoint 1.1, queue = com.apple.main-thread 11 12 int main() 13 { 14 -> struct i10 v = fun(); 15 }	(gdb) b main Breakpoint 1 at 0x100000edb: file test.c, line 14. (gdb) r Starting program: /private/tmp/a.out Reading symbols for shared libraries +. done Breakpoint 1, main () at test.c:14 14 struct i10 v = fun();
(lldb) disass 0x100000ed0: pushq %rbp 0x100000ed1: movq %rsp, %rbp 0x100000ed4: subq $131072, %rsp 0x100000edb: leaq -131072(%rbp), %rdi 0x100000ee2: movl $0, %eax 0x100000ee7: callq 0x100000ea0 ; fun at /private/tmp/test.c:7 0x100000eec: leave 0x100000eed: ret	(gdb) disass main Dump of assembler code for function main: 0x0000000100000ed0 : push %rbp 0x0000000100000ed1 : mov %rsp,%rbp 0x0000000100000ed4 : sub $0x20000,%rsp 0x0000000100000edb : lea -0x20000(%rbp),%rdi 0x0000000100000ee2 : mov $0x0,%eax 0x0000000100000ee7 : callq 0x100000ea0 0x0000000100000eec : leaveq 0x0000000100000eed : retq End of assembler dump.