How do you set breakpoints in the lldb terminal for swift?-CodePudding

I am trying to debug my swift program using lldb in terminal. I have compiled my code with the command

swiftc hello.swift

then I ran lldb using

lldb hello

in the lldb program I tried to set a break point using

(lldb) breakpoint set --file hello.swift --line 10

but I got the error

Breakpoint 2: no locations (pending).
WARNING:  Unable to resolve breakpoint to any actual locations.

here is the code for hello.swift:

func answer()-> Int{
    var value = 12
    value = value   9
    return 4 * value
}

let arr = [0, 1, 2, 3, 4]

for _ in arr{
    print(answer())
}

what am I doing wrong?

CodePudding user response：

You should set the -g option when compiling the program. From swiftc --help:

-g Emit debug info. This is the preferred setting for debugging with LLDB.

Example session:

% swiftc -g hello.swift

% lldb hello
(lldb) target create "hello"
Current executable set to '/tmp/x/hello' (x86_64).

(lldb) breakpoint set --file hello.swift --line 10
Breakpoint 1: where = hello`main   256 at hello.swift:10:11, address = 0x0000000100003bf0

(lldb) run
Process 15967 launched: '/tmp/x/hello' (x86_64)
Process 15967 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x0000000100003bf0 hello`main at hello.swift:10:11
   7    let arr = [0, 1, 2, 3, 4]
   8    
   9    for _ in arr{
-> 10       print(answer())
   11   }
Target 0: (hello) stopped.