docs/text/NDK-DEPENDS.text

'ndk-depends' Overview
===

Introduction:
-------------

The `ndk-depends` tool that comes with this Android NDK allows you to dump
the ELF dependencies of a given ELF shared library or executable.

With the --print-java option, it can also be used to generate a Java
source fragment to load your native library and its dependencies in the
correct order (see example below).

Use '`ndk-depends --help`' for complete usage information.

This tool is designed to support:

  - Either 32-bit or 64-bit ELF binaries.
  - Either little-endian or big-endian ELF binaries.
  - Unicode file paths, on Windows.

Note: The Windows binary will NOT work with Cygwin paths !

Examples:
---------

* `ndk-depends path/to/libfoo.so`
> Dump all dependencies of libfoo.so, in topological order, so
  that any library listed in the result appears before any other
  library it depends on.

* `ndk-depends --print-paths path/to/libfoo.so`
> Same as above, but also prints the path of the libraries on
  your host file system.

* `ndk-depends -L some/other/path path/to/libfoo.so`
> Append 'some/other/path' to the search path for depending libraries
  when looking at the dependencies for 'libfoo.so'

* `ndk-depends --print-direct path/to/libfoo.so`
> Only print the _direct_ dependencies of libfoo.so, and nothing
  else, in the order they appear in the file.

* `ndk-depends path/to/libfoo.so --print-java`
> Prints a Java source fragment that corresponds to the load
  of 'libfoo' with System.loadLibrary(). This lists all libraries
  in reverse order, and ignores system libraries (e.g. libc.so).

* `ndk-depends path/to/libfoo.so --print-dot | dot -Tpng -o /tmp/graph.png`
> Prints the dependency graph as Graphviz .dot file, then generate
  a PNG image for it.

* `ndk-depends --help`
> Print complete usage details.

Let's assume your project has the several libraries:

        libfoo.so -> depends on libbar.so and libzoo.so
        libbar.so -> depends on the system's liblog.so
        libzoo.so -> depends on libbar.so

Then '`ndk-depends libs/armeabi/libfoo.so`' will typically print:

        libfoo.so
        libzoo.so
        libbar.so
        liblog.so

And '`ndk-depends --print-java libs/armeabi/libfoo.so`' will print:

        System.loadLibrary("bar");
        System.loadLibrary("zoo");
        System.loadLibrary("foo");

This is handy to avoid computing the reverse library order yourself
for complex projects.

For more details, see the output of '`ndk-depends --help`'.