How to use atos? (or addr2line on Mac OS X)

Question

I see the following example using addr2line. But the interfaces of atos and addr2line are different. I am not sure how to make it work using atos. Could anybody show me how to convert it to using atos?

https://balau82.wordpress.com/2010/10/06/trace-and-profile-function-calls-with-gcc/

Alternatively, is there a way to make addr2line work on Mac (It is known that addr2line does not work well on Mac OS X)? I just get ?? instead of function names using addr2line. Thanks.

Answer 1

There are two ways addr2line is used in the script in the article you linked:

addr2line -f -e ${EXECUTABLE} ${FADDR}

and:

addr2line -s -e ${EXECUTABLE} ${CADDR}

The first one uses the -f option, which causes addr2line to output the function name on a line by itself before showing the filename and line number on a second line. In that script, only the first line is used (it's piped through head -1).

atos always outputs the function name, so there's no need for an equivalent to that -f option. [Whereas addr2line is short for "address to line" (filename and line number), making the function name ancillary to its main purpose, atos is short for "address to symbol", so producing the symbol name is its core purpose.]

The next option used for addr2line is -e ${EXECUTABLE}. The equivalent for atos is -o ${EXECUTABLE}.

After that, the arguments are addresses. That's the same between addr2line and atos.

So, the atos command that corresponds to addr2line -f -e ${EXECUTABLE} ${FADDR} is atos -o ${EXECUTABLE} ${FADDR}. However, the script is "parsing" the output from the command and the two programs produce output in different formats. To get just the function name from the output of atos, you can pipe it through perl -lne 'print "$1" if m/^(.*) \(in .*\)/'.

The second type of addr2line command does not use the -f option, so it doesn't print the function name. It's just used to get the filename and line number. As mentioned before, atos always prints the function name. So, the atos command is the same as before. To get just the file name and line number from its output, you can pipe it through perl -lne 'print "$1" if m/^.* \(in .*\) \((.*)\)$/'.

This addr2line command also uses the -s option. That makes it print only the basename of the file path, not the whole path. That's what atos does anyway, so there's no need to translate that option to anything.