stringWithFormat not working in LLDB

Question

Why doesn't this work?

(lldb) po [NSString stringWithFormat:@"%f", 1.0]
error: too many arguments to method call, expected 1, have 2
error: 1 errors parsing expression

But this does:

(lldb) p (void)printf("%f", 1.0)
1.000000

Is Objective-C variable arguments syntax not supported in LLDB?

Thanks, Martin R. It's apparently a general LLDB issue with variable argument lists. — Ortwin Gentz, Oct 18 '13 at 11:29

score 22 · Accepted Answer · edited May 23 '17 at 11:46

22

As Martin R pointed out in the comments, it's apparently a general LLDB issue with variable argument lists.

On the other hand, as Patrik Schmittat pointed out, -initWithFormat: works just fine:

(lldb) po [[NSString alloc] initWithFormat:@"%f", 1.0]
1.000000

edited May 23 '17 at 11:46

Community

answered Oct 18 '13 at 11:41

Ortwin Gentz

score 2 · Answer 2 · edited May 23 '17 at 12:25

2

Basically this is the bug in lldb, if you try the same in gdb it works. 
lldb is only passing the low 32 bits of the argument.

Also samthing i have tried in GDB and its work fine as attached in the screens shot:- enter image description here

Now i tried the samething in GDB:- enter image description here

edited May 23 '17 at 12:25

Community

answered Oct 18 '13 at 11:15

Hussain Shabbir

Hm, but `[NSString stringWithFormat:@"%@", @"test"]` and `[NSString stringWithFormat:@"%d", 1]` don't work either. It seems it's a general LLDB issue with variable argument lists. – Ortwin Gentz Oct 18 '13 at 11:27
yes, even this will also doesn't work – Hussain Shabbir Oct 18 '13 at 11:32
What are you people running under? Mac 32 bit? iOS 32 bit? Mac 64 bit? Simulator? ... ? Maybe it works on 32-bit OSes? – uliwitness Oct 18 '13 at 11:33
Issue occurs on iPhone 5s, 4s and the simulator (32 and 64 bit mode). So it's obviously architecture independent. – Ortwin Gentz Oct 18 '13 at 11:37

2 Answers2