• --help

  Display a short help about the command and exit.

• –version | -v

  Display the version of the program and exit.

• --list-undefined-symbols | -u

  Display the list of undefined symbols of the application and exit.

• --show-base-names | -b

  In the resulting report emitted by the tool, this option makes the application and libraries be referred to by their base names only; not by a full absolute name. This can be useful for use in scripts that wants to compare names of the application and libraries independently of what their directory names are.

• --app-debug-info-dir | --appd <path-to-app-debug-info-directory>

  Set the path to the directory under which the debug information of the application is supposed to be laid out. This is useful for application binaries for which the debug info is in a separate set of files.

• --lib-debug-info-dir1 | --libd1 <path-to-lib1-debug-info>

  Set the path to the directory under which the debug information of the first version of the shared library is supposed to be laid out. This is useful for shared library binaries for which the debug info is in a separate set of files.

• --lib-debug-info-dir2 | --libd2 <path-to-lib1-debug-info>

  Set the path to the directory under which the debug information of the second version of the shared library is supposed to be laid out. This is useful for shared library binaries for which the debug info is in a separate set of files.

• --suppressions | --suppr <path-to-suppressions>

  Use a suppression specification file located at path-to-suppressions. Note that this option can appear multiple times on the command line; all the suppression specification files are then taken into account.

• --no-show-locs

• --ctf

  When comparing binaries, extract ABI information from CTF debug information, if present.

• --fail-no-debug-info

  If no debug info was found, then this option makes the program to fail. Otherwise, without this option, the program will attempt to compare properties of the binaries that are not related to debug info, like pure ELF properties.

• --ignore-soname

  Ignore differences in the SONAME when doing a comparison

• --weak-mode

  This triggers the weak mode of abicompat. In this mode, only one version of the library is required. That is, abicompat is invoked like this:

abicompat --weak-mode <the-application> <the-library>

Note that the --weak-mode option can even be omitted if only one version of the library is given, along with the application; in that case, abicompat automatically switches to operate in weak mode:

abicompat <the-application> <the-library>

In this weak mode, the types of functions and variables exported by the library and consumed by the application (as in, the symbols of the these functions and variables are undefined in the application and are defined and exported by the library) are compared to the version of these types as expected by the application. And if these two versions of types are different, abicompat tells the user what the differences are.

In other words, in this mode, abicompat checks that the types of the functions and variables exported by the library mean the same thing as what the application expects, as far as the ABI is concerned.

Note that in this mode, abicompat doesn’t detect exported functions or variables (symbols) that are expected by the application but that are removed from the library. That is why it is called weak mode.

•

Detecting a possible ABI incompatibility in a new shared library version:

$ cat -n test0.h


     1  struct foo


     2  {


     3    int m0;


     4


     5    foo()


     6      : m0()


     7    {}


     8  };


     9


    10  foo*


    11  first_func();


    12


    13  void


    14  second_func(foo&);


    15


    16  void


    17  third_func();
$
$ cat -n test-app.cc


     1  // Compile with:


     2  //  g++ -g -Wall -o test-app -L. -ltest-0 test-app.cc


     3


     4  #include "test0.h"


     5


     6  int


     7  main()


     8  {


     9    foo* f = first_func();


    10    second_func(*f);


    11    return 0;


    12  }
$
$ cat -n test0.cc


     1  // Compile this with:


     2  //  g++ -g -Wall -shared -o libtest-0.so test0.cc


     3


     4  #include "test0.h"


     5


     6  foo*


     7  first_func()


     8  {


     9    foo* f = new foo();


    10    return f;


    11  }


    12


    13  void


    14  second_func(foo&)


    15  {


    16  }


    17


    18  void


    19  third_func()


    20  {


    21  }
$
$ cat -n test1.h


     1  struct foo


     2  {


     3    int  m0;


     4    char m1; /* <-- a new member got added here! */


     5


     6    foo()


     7    : m0(),


     8      m1()


     9    {}


    10  };


    11


    12  foo*


    13  first_func();


    14


    15  void


    16  second_func(foo&);


    17


    18  void


    19  third_func();
$
$ cat -n test1.cc


     1  // Compile this with:


     2  //  g++ -g -Wall -shared -o libtest-1.so test1.cc


     3


     4  #include "test1.h"


     5


     6  foo*


     7  first_func()


     8  {


     9    foo* f = new foo();


    10    return f;


    11  }


    12


    13  void


    14  second_func(foo&)


    15  {


    16  }


    17


    18  /* Let's comment out the definition of third_func()


    19     void


    20     third_func()


    21     {


    22     }


    23  */
$

$ g++ -g -Wall -shared -o libtest-0.so test0.cc
$ g++ -g -Wall -shared -o libtest-1.so test1.cc

$ g++ -g -Wall -o test-app -L. -ltest-0.so test-app.cc

$ abicompat test-app libtest-0.so libtest-1.so
ELF file 'test-app' might not be ABI compatible with 'libtest-1.so' due to differences with 'libtest-0.so' below:
Functions changes summary: 0 Removed, 2 Changed, 0 Added functions
Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
2 functions with some indirect sub-type change:


  [C]'function foo* first_func()' has some indirect sub-type changes:


    return type changed:


      in pointed to type 'struct foo':


        size changed from 32 to 64 bits


        1 data member insertion:


          'char foo::m1', at offset 32 (in bits)


  [C]'function void second_func(foo&)' has some indirect sub-type changes:


    parameter 0 of type 'foo&' has sub-type changes:


      referenced type 'struct foo' changed, as reported earlier
$

$ abicompat --weak-mode test-app libtest-1.so
functions defined in library


    'libtest-1.so'
have sub-types that are different from what application


    'test-app'
expects:


  function foo* first_func():


    return type changed:


      in pointed to type 'struct foo':


        size changed from 32 to 64 bits


        1 data member insertion:


          'char foo::m1', at offset 32 (in bits)
$