atos(1)

NAME
atos - convert numeric addresses to symbols of binary images or processes

SYNOPSIS
atos [-o <binary-image-file>] [-p <pid> | <partial-executable-name>] [-arch architecture] [-l <load-address>] [-s <slide>] [-printHeader] [-f <address-input-file>] [<address> ...]

DESCRIPTION
The atos command converts numeric addresses to their symbolic equivalents. If full debug symbol information is available, for example in a .app.dSYM sitting beside a .app, then the output of atos will include file name and source line number information.

The input addresses may be given in one of three ways:

1.  A list of addresses at the end of the argument list.

2.  Using the -f <address-input-file> argument to specify the path of an input file containing whitespace-separated numeric addresses.

3.  If no addresses were directly specified, atos enters an interactive mode, reading addresses from stdin.

The symbols are found in either a binary image file or in a currently executing process, as specified by:

-o <binary-image-file>
    The path to a binary image file in which to look up symbols.

-p <pid> | <partial-executable-name>
    The process ID or the partial name of a currently executing process in which to look up symbols.

Multiple process IDs or paths can be specified if necessary, and the two can be mixed in any order. When working with a Mach-O binary image file, atos considers only addresses and symbols defined in that binary image file, at their default locations (unless the -l or -s option is given). When working with a running process, atos considers addresses and symbols defined in all binary images currently loaded by that process, at their loaded locations.

The following additional options are available.

-arch architecture
    The particular architecure of a binary image file in which to look up symbols.

-l <load-address>
    The load address of the binary image. This value is always assumed to be in hex, even without a "0x" prefix. The input addresses are assumed to be in a binary image with that load address. Load addresses for binary images can be found in the Binary Images: section at the bottom of crash, sample, leaks, and malloc_history reports.

-s <slide>
    The slide value of the binary image -- this is the difference between the load address of a binary image, and the address at which the binary image was built. This slide value is subtracted from the input addresses. It is usually easier to directly specify the load address with the -l argument than to manually calculate a slide value.

-printHeader
    If a process was specified, the first line of atos output should be a header of the form "Looking up symbols in process <pid> named: <process-name>". This is primarily used when atos is invoked as part of a stackshot(1) run, for verification of the process ID and name.

EXAMPLE
A stripped, optimized version of Sketch was built as an x86_64 position-independent executable (PIE) into /BuildProducts/Release. Full debug symbol information is available in Sketch.app.dSYM, which sits alongside Sketch.app. When Sketch.app was run, the Sketch binary (which was built at 0x100000000) was loaded at 0x10acde000. Running 'sample Sketch' showed 3 addresses that we want to get symbol information for -- 0x10acea1d3, 0x10ace4bea, and 0x10ace4b7a.

First notice that the .dSYM is next to the .app:

    % ls -1 /BuildProducts/Release/
    Sketch.app
    Sketch.app.dSYM

Now, to symbolicate, we run atos with the -o flag specifying the path to the actual Sketch executable (not the .app wrapper), the -arch x86_64 flag, and the -l 0x10acde000 flag to specify the load address.

    % atos -o /BuildProducts/Release/Sketch.app/Contents/MacOS/Sketch -arch x86_64 -l 0x10acde000  0x10acea1d3 0x10ace4bea 0x10ace4b7a
    -[SKTGraphicView drawRect:] (in Sketch) (SKTGraphicView.m:445)
    -[SKTGraphic drawHandlesInView:] (in Sketch) (NSGeometry.h:110)
    -[SKTGraphic drawHandleInView:atPoint:] (in Sketch) (SKTGraphic.m:490)

GETTING SYMBOLS FOR A DIFFERENT MACHINE ARCHITECTURE
It is possible to get symbols for addresses from a different machine architecture than the system on which atos is running. For example, when running atos on an Intel-based system, one may wish to get the symbol for an address that came from a backtrace of a process running on an ARM device. To do so, use the -arch flag to specify the desired architecture (such as i386 or arm) and pass in a corresponding symbol-rich Mach-O binary image file with a binary image of the corresponding architecture (such as a Universal Binary).