C++ Standard Library ABI
The latest version of this document is always available at
http://gcc.gnu.org/onlinedocs/libstdc++/abi.html
http://gcc.gnu.org/onlinedocs/libstdc++/abi.html
.
To the
http://gcc.gnu.org/libstdc++/
libstdc++-v3 homepage
.
The C++ interface
C++ applications often dependent on specific language support
routines, say for throwing exceptions, or catching exceptions, and
perhaps also dependent on features in the C++ Standard Library.
The C++ Standard Library has many include files, types defined in
those include files, specific named functions, and other behavior. The
text of these behaviors, as written in source include files, is called
the Application Programing Interface, or API.
Furthermore, C++ source that is compiled into object files is
transformed by the compiler: it arranges objects with specific
alignment and in a particular layout, mangling names according to a
well-defined algorithm, has specific arrangements for the support of
virtual functions, etc. These details are defined as the compiler
Application Binary Interface, or ABI. The GNU C++ compiler uses an
industry-standard C++ ABI starting with version 3. Details can be
found in the
http://www.codesourcery.com/cxx-abi/abi.html
ABI specification
.
The GNU C++ compiler, g++, has a compiler command line option to
switch between various different C++ ABIs. This explicit version
switch is the flag
-fabi-version
. In addition, some
g++ command line options may change the ABI as a side-effect of
use. Such flags include
-fpack-struct
and
-fno-exceptions
, but include others: see the complete
list in the GCC manual under the heading
http://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html#Code%20Gen%20Options
Options
for Code Generation Conventions
.
The configure options used when building a specific libstdc++
version may also impact the resulting library ABI. The available
configure options, and their impact on the library ABI, are documented
http://gcc.gnu.org/onlinedocs/libstdc++/configopts.html
here
.
Putting all of these ideas together results in the C++ Standard
library ABI, which is the compilation of a given library API by a
given compiler ABI. In a nutshell:
library API + compiler ABI = library ABI
The library ABI is mostly of interest for end-users who have
unresolved symbols and are linking dynamically to the C++ Standard
library, and who thus must be careful to compile their application
with a compiler that is compatible with the available C++ Standard
library binary. In this case, compatible is defined with the equation
above: given an application compiled with a given compiler ABI and
library API, it will work correctly with a Standard C++ Library
created with the same constraints.
To use a specific version of the C++ ABI, one must use a
corresponding GNU C++ toolchain (Ie, g++ and libstdc++) that
implements the C++ ABI in question.
Versioning
The C++ interface has evolved throughout the history of the GNU
C++ toolchain. With each release, various details have been changed so
as to give distinct versions to the C++ interface.
Goals of versioning
Extending existing, stable ABIs. Versioning gives subsequent stable
releases series libraries the ability to add new symbols and add
functionality, all the while retaining backwards compatibility with
the previous releases in the series. Note: the reverse is not true. It
is not possible to take binaries linked with the latest version of a
release series (if symbols have been added) and expect the initial
release of the series to remain link compatible.
Allows multiple, incompatible ABIs to coexist at the same time.
Version History
How can this complexity be managed? What does C++ versioning mean?
Because library and compiler changes often make binaries compiled
with one version of the GNU tools incompatible with binaries
compiled with other (either newer or older) versions of the same GNU
tools, specific techniques are used to make managing this complexity
easier.
The following techniques are used:
Release versioning on the libgcc_s.so binary. This is
implemented via file names and the ELF DT_SONAME mechanism (at least
on ELF systems).
It is versioned as follows:
gcc-3.0.0: libgcc_s.so.1
gcc-3.0.1: libgcc_s.so.1
gcc-3.0.2: libgcc_s.so.1
gcc-3.0.3: libgcc_s.so.1
gcc-3.0.4: libgcc_s.so.1
gcc-3.1.0: libgcc_s.so.1
gcc-3.1.1: libgcc_s.so.1
gcc-3.2.0: libgcc_s.so.1
gcc-3.2.1: libgcc_s.so.1
gcc-3.2.2: libgcc_s.so.1
gcc-3.2.3: libgcc_s.so.1
gcc-3.3.0: libgcc_s.so.1
gcc-3.3.1: libgcc_s.so.1
gcc-3.3.2: libgcc_s.so.1
gcc-3.3.3: libgcc_s.so.1
gcc-3.4.0: on m68k-linux and hppa-linux this is either libgcc_s.so.1
(when configuring
--with-sjlj-exceptions
) or
libgcc_s.so.2. For all others, this is libgcc_s.so.1.
Release versioning on the libstdc++.so binary, implemented in the same was as the libgcc_s.so binary, above.
It is versioned as follows:
gcc-3.0.0: libstdc++.so.3.0.0
gcc-3.0.1: libstdc++.so.3.0.1
gcc-3.0.2: libstdc++.so.3.0.2
gcc-3.0.3: libstdc++.so.3.0.2 (Error should be libstdc++.so.3.0.3)
gcc-3.0.4: libstdc++.so.3.0.4
gcc-3.1.0: libstdc++.so.4.0.0
gcc-3.1.1: libstdc++.so.4.0.1
gcc-3.2.0: libstdc++.so.5.0.0
gcc-3.2.1: libstdc++.so.5.0.1
gcc-3.2.2: libstdc++.so.5.0.2
gcc-3.2.3: libstdc++.so.5.0.3 (Not strictly required)
gcc-3.3.0: libstdc++.so.5.0.4
gcc-3.3.1: libstdc++.so.5.0.5
gcc-3.3.2: libstdc++.so.5.0.5
gcc-3.3.3: libstdc++.so.5.0.5
gcc-3.4.0: libstdc++.so.6.0.0
gcc-3.4.1: libstdc++.so.6.0.1
Symbol versioning on the libgcc_s.so binary.
mapfile: gcc/libgcc-std.ver
It is versioned with the following labels and version definitions:
gcc-3.0.0: GCC_3.0
gcc-3.0.1: GCC_3.0
gcc-3.0.2: GCC_3.0
gcc-3.0.3: GCC_3.0
gcc-3.0.4: GCC_3.0
gcc-3.1.0: GCC_3.0
gcc-3.1.1: GCC_3.0
gcc-3.2.0: GCC_3.0
gcc-3.2.1: GCC_3.0
gcc-3.2.2: GCC_3.0
gcc-3.2.3: GCC_3.0
gcc-3.3.0: GCC_3.0
gcc-3.3.1: GCC_3.0
gcc-3.3.2: GCC_3.0
gcc-3.3.3: GCC_3.0
gcc-3.4.0: GCC_3.0
Symbol versioning on the libstdc++.so binary.
mapfile: libstdc++-v3/config/linker-map.gnu
It is versioned with the following labels and version
definitions, where the version definition is the maximum for a
particular release. Note, only symbol which are newly introduced
will use the maximum version definition. Thus, for release series
with the same label, but incremented version definitions, the later
release has both versions. (An example of this would be the
gcc-3.2.1 release, which has GLIBCPP_3.2.1 for new symbols and
GLIBCPP_3.2 for symbols that were introduced in the gcc-3.2.0
release.)
gcc-3.0.0: (Error, not versioned)
gcc-3.0.1: (Error, not versioned)
gcc-3.0.2: (Error, not versioned)
gcc-3.0.3: (Error, not versioned)
gcc-3.0.4: (Error, not versioned)
gcc-3.1.0: GLIBCPP_3.1, CXXABI_1
gcc-3.1.1: GLIBCPP_3.1, CXXABI_1
gcc-3.2.0: GLIBCPP_3.2, CXXABI_1.2
gcc-3.2.1: GLIBCPP_3.2.1, CXXABI_1.2
gcc-3.2.2: GLIBCPP_3.2.2, CXXABI_1.2
gcc-3.2.3: GLIBCPP_3.2.2, CXXABI_1.2
gcc-3.3.0: GLIBCPP_3.2.2, CXXABI_1.2.1
gcc-3.3.1: GLIBCPP_3.2.3, CXXABI_1.2.1
gcc-3.3.2: GLIBCPP_3.2.3, CXXABI_1.2.1
gcc-3.3.3: GLIBCPP_3.2.3, CXXABI_1.2.1
gcc-3.4.0: GLIBCXX_3.4, CXXABI_1.3
gcc-3.4.1: GLIBCXX_3.4.1, CXXABI_1.3
Incremental bumping of a compiler pre-defined macro,
__GXX_ABI_VERSION. This macro is defined as the version of the
compiler v3 ABI, with g++ 3.0.x being version 100. This macro will
be automatically defined whenever g++ is used (the curious can
test this by invoking g++ with the '-v' flag.)
This macro was defined in the file "lang-specs.h" in the gcc/cp directory.
Later versions defined it in "c-common.c" in the gcc directory, and from
G++ 3.4 it is defined in c-cppbuiltin.c and its value determined by the
'-fabi-version' command line option.
It is versioned as follows, where 'n' is given by '-fabi-version=n':
gcc-3.0.x: 100
gcc-3.1.x: 100 (Error, should be 101)
gcc-3.2.x: 102
gcc-3.3.x: 102
gcc-3.4.x: 102 (when n=1)
gcc-3.4.x: 1000 + n (when n>1)
gcc-3.4.x: 999999 (when n=0)
Changes to the default compiler option for
-fabi-version
.
It is versioned as follows:
gcc-3.0.x: (Error, not versioned)
gcc-3.1.x: (Error, not versioned)
gcc-3.2.x:
-fabi-version=1
gcc-3.3.x:
-fabi-version=1
gcc-3.4.x:
-fabi-version=2
Incremental bumping of a library pre-defined macro. For releases
before 3.4.0, the macro is __GLIBCPP__. For later releases, it's
__GLIBCXX__. (The libstdc++ project generously changed from CPP to
CXX throughout its source to allow the "C" pre-processor the CPP
macro namespace.) These macros are defined as the date the library
was released, in compressed ISO date format, as an unsigned long.
In addition, the pre-defined macro is defined in the file
"c++config" in the "libstdc++-v3/include/bits" directory and is
changed every night by an automated script.
It is versioned as follows:
gcc-3.0.0: 20010615
gcc-3.0.1: 20010819
gcc-3.0.2: 20011023
gcc-3.0.3: 20011220
gcc-3.0.4: 20020220
gcc-3.1.0: 20020514
gcc-3.1.1: 20020725
gcc-3.2.0: 20020814
gcc-3.2.1: 20021119
gcc-3.2.2: 20030205
gcc-3.2.3: 20030422
gcc-3.3.0: 20030513
gcc-3.3.1: 20030804
gcc-3.3.2: 20031016
gcc-3.3.3: 20040214
gcc-3.4.0: 20040419
gcc-3.4.1: 20040701
Incremental bumping of a library pre-defined macro,
_GLIBCPP_VERSION. This macro is defined as the released version of
the library, as a string literal. This is only implemented in
gcc-3.1.0 releases and higher, and is deprecated in 3.4 (where it
is called _GLIBCXX_VERSION).
This macro is defined in the file "c++config" in the
"libstdc++-v3/include/bits" directory and is generated
automatically by autoconf as part of the configure-time generation
of config.h.
It is versioned as follows:
gcc-3.0.0: "3.0.0"
gcc-3.0.1: "3.0.0" (Error, should be "3.0.1")
gcc-3.0.2: "3.0.0" (Error, should be "3.0.2")
gcc-3.0.3: "3.0.0" (Error, should be "3.0.3")
gcc-3.0.4: "3.0.0" (Error, should be "3.0.4")
gcc-3.1.0: "3.1.0"
gcc-3.1.1: "3.1.1"
gcc-3.2.0: "3.2"
gcc-3.2.1: "3.2.1"
gcc-3.2.2: "3.2.2"
gcc-3.2.3: "3.2.3"
gcc-3.3.0: "3.3"
gcc-3.3.1: "3.3.1"
gcc-3.3.2: "3.3.2"
gcc-3.3.3: "3.3.3"
gcc-3.4.0: "version-unused"
gcc-3.4.1: "version-unused"
Matching each specific C++ compiler release to a specific set of
C++ include files. This is only implemented in gcc-3.1.1 releases
and higher.
All C++ includes are installed in include/c++, then nest in a
directory hierarchy corresponding to the C++ compiler's released
version. This version corresponds to the variable "gcc_version" in
"libstdc++-v3/acinclude.m4," and more details can be found in that
file's macro GLIBCXX_CONFIGURE (GLIBCPP_CONFIGURE before gcc-3.4.0).
C++ includes are versioned as follows:
gcc-3.0.0: include/g++-v3
gcc-3.0.1: include/g++-v3
gcc-3.0.2: include/g++-v3
gcc-3.0.3: include/g++-v3
gcc-3.0.4: include/g++-v3
gcc-3.1.0: include/g++-v3
gcc-3.1.1: include/c++/3.1.1
gcc-3.2.0: include/c++/3.2
gcc-3.2.1: include/c++/3.2.1
gcc-3.2.2: include/c++/3.2.2
gcc-3.2.3: include/c++/3.2.3
gcc-3.3.0: include/c++/3.3
gcc-3.3.1: include/c++/3.3.1
gcc-3.3.2: include/c++/3.3.2
gcc-3.3.3: include/c++/3.3.3
gcc-3.4.0: include/c++/3.4.0
gcc-3.4.1: include/c++/3.4.1
Taken together, these techniques can accurately specify interface
and implementation changes in the GNU C++ tools themselves. Used
properly, they allow both the GNU C++ tools implementation, and
programs using them, an evolving yet controlled development that
maintains backward compatibility.
Minimum requirements for a versioned ABI
Minimum environment that supports a versioned ABI: A supported
dynamic linker, a GNU linker of sufficient vintage to understand
demangled C++ name globbing (ld), a shared executable compiled with
g++, and shared libraries (libgcc_s, libstdc++-v3) compiled by a
compiler (g++) with a compatible ABI. Phew.
On top of all that, an additional constraint: libstdc++ did not
attempt to version symbols (or age gracefully, really) until version
3.1.0.
Most modern Linux and BSD versions, particularly ones using
gcc-3.1.x tools and more recent vintages, will meet the requirements above.
What configure options impact symbol versioning?
It turns out that most of the configure options that change default
behavior will impact the mangled names of exported symbols, and thus
impact versioning and compatibility.
For more information on configure options, including ABI impacts, see:
http://gcc.gnu.org/onlinedocs/libstdc++/configopts.html
There is one flag that explicitly deals with symbol versioning:
--enable-symvers.
In particular, libstdc++-v3/acinclude.m4 has a macro called
GLIBCXX_ENABLE_SYMVERS that defaults to yes (or the argument passed
in via --enable-symvers=foo). At that point, the macro attempts to
make sure that all the requirement for symbol versioning are in
place. For more information, please consult acinclude.m4.
How to tell if symbol versioning is, indeed, active?
When the GNU C++ library is being built with symbol versioning on,
you should see the following at configure time for libstdc++-v3:
checking versioning on shared library symbols... gnu
If you don't see this line in the configure output, or if this line
appears but the last word is 'no', then you are out of luck.
If the compiler is pre-installed, a quick way to test is to compile
the following (or any) simple C++ file and link it to the shared
libstdc++ library:
#include <iostream>
int main()
{ std::cout << "hello" << std::endl; return 0; }
%g++ hello.cc -o hello.out
%ldd hello.out
libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0x00764000)
libm.so.6 => /lib/tls/libm.so.6 (0x004a8000)
libgcc_s.so.1 => /mnt/hd/bld/gcc/gcc/libgcc_s.so.1 (0x40016000)
libc.so.6 => /lib/tls/libc.so.6 (0x0036d000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x00355000)
%nm hello.out
If you see symbols in the resulting output with "GLIBCXX_3" as part
of the name, then the executable is versioned. Here's an example:
U _ZNSt8ios_base4InitC1Ev@@GLIBCXX_3.4
Library allowed ABI changes
The following will cause the library minor version number to
increase, say from "libstdc++.so.3.0.4" to "libstdc++.so.3.0.5".
adding an exported global or static data member
adding an exported function, static or non-virtual member function
adding an exported symbol or symbols by additional instantiations
Other allowed changes are possible.
Library disallowed ABI changes
The following non-exhaustive list will cause the library major version
number to increase, say from "libstdc++.so.3.0.4" to
"libstdc++.so.4.0.0".
changes in the gcc/g++ compiler ABI
changing size of an exported symbol
changing alignment of an exported symbol
changing the layout of an exported symbol
changing mangling on an exported symbol
deleting an exported symbol
changing the inheritance properties of a type by adding or removing
base classes
changing the size, alignment, or layout of types
specified in the C++ standard. These may not necessarily be
instantiated or otherwise exported in the library binary, and
include all the required locale facets, as well as things like
std::basic_streambuf, et al.
adding an explicit copy constructor or destructor to a
class that would otherwise have implicit versions. This will change
the way the compiler deals with this class in by-value return
statements or parameters: instead of being passing instances of this
class in registers, the compiler will be forced to use memory. See
http://www.codesourcery.com/cxx-abi/abi.html#calls
this part
of the C++ ABI documentation for further details.
Library implementation strategy
Separation of interface and implementation
This is accomplished by two techniques that separate the API from
the ABI: forcing undefined references to link against a library binary
for definitions.
Include files have declarations, source files have defines
For non-templatized types, such as much of
class
locale
, the appropriate standard C++ include, say
locale
, can contain full declarations, while various
source files (say
locale.cc, locale_init.cc,
localename.cc
) contain definitions.
Extern template on required types
For parts of the standard that have an explicit list of required
instantiations, the GNU extension syntax
extern template
can be used to control where template definitions
reside. By marking required instantiations as
extern
template
in include files, and providing explicit
instantiations in the appropriate instantiation files, non-inlined
template functions can be versioned. This technique is mostly used
on parts of the standard that require
char
and
wchar_t
instantiations, and includes
basic_string
, the locale facets, and the types in
iostreams
.
In addition, these techniques have the additional benefit that
they reduce binary size, which can increase runtime performance.
Namespaces linking symbol definitions to export mapfiles
All symbols in the shared library binary are processed by a linker
script at build time that either allows or disallows external
linkage. Because of this, some symbols, regardless of normal C/C++
linkage, are not visible. Symbols that are internal have several
appealing characteristics: by not exporting the symbols, there are no
relocations when the shared library is started and thus this makes for
faster runtime loading performance by the underlying dynamic loading
mechanism. In addition, they have the possibility of changing without
impacting ABI compatibility.
The following namespaces are transformed by the mapfile:
namespace std
Defaults to exporting all symbols in label
GLIBCXX
that do not begin with an underscore, ie
__test_func
would not be exported by default. Select
exceptional symbols are allowed to be visible.
namespace __gnu_cxx
Defaults to not exporting any symbols in label
GLIBCXX
, select items are allowed to be visible.
namespace __gnu_internal
Defaults to not exported, no items are allowed to be visible.
namespace __cxxabiv1
, aliased to
namespace abi
Defaults to not exporting any symbols in label
CXXABI
, select items are allowed to be visible.
Freezing the API
Disallowed changes, as above, are not made on a stable release
branch. Enforcement tends to be less strict with GNU extensions that
standard includes.
Testing ABI changes
Testing for GNU C++ ABI changes is composed of two distinct areas:
testing the C++ compiler (g++) for compiler changes, and testing the
C++ library (libstdc++) for library changes.
Testing the C++ compiler ABI can be done various ways.
One.
Intel ABI checker. More information can be obtained
http://developer.intel.com/software/products/opensource/
here.
Two.
The second is yet unreleased, but has been announced on the gcc
mailing list. It is yet unspecified if these tools will be freely
available, and able to be included in a GNU project. Please contact
Mark Mitchell (mark@codesourcery.com) for more details, and current
status.
Three.
Involves using the vlad.consistency test framework. This has also been
discussed on the gcc mailing lists.
Testing the C++ library ABI can also be done various ways.
One.
(Brendan Kehoe, Jeff Law suggestion to run 'make check-c++' two ways,
one with a new compiler and an old library, and the other with an old
compiler and a new library, and look for testsuite regressions)
Details on how to set this kind of test up can be found here:
http://gcc.gnu.org/ml/gcc/2002-08/msg00142.html
Two.
Use the 'make check-abi' rule in the libstdc++-v3 Makefile.
This is a proactive check the library ABI. Currently, exported symbol
names that are either weak or defined are checked against a last known
good baseline. Currently, this baseline is keyed off of 3.4.0
binaries, as this was the last time the .so number was incremented. In
addition, all exported names are demangled, and the exported objects
are checked to make sure they are the same size as the same object in
the baseline.
Notice that each baseline is relative to a
default
configured library and compiler: in particular, if options such as
--enable-clocale, or --with-cpu, in case of multilibs, are used at
configure time, the check may fail, either because of substantive
differences or because of limitations of the current checking
machinery.
This dataset is insufficient, yet a start. Also needed is a
comprehensive check for all user-visible types part of the standard
library for sizeof() and alignof() changes.
Verifying compatible layouts of objects is not even attempted.  It
should be possible to use sizeof, alignof, and offsetof to compute
offsets for each structure and type in the standard library, saving to
another datafile. Then, compute this in a similar way for new
binaries, and look for differences.
Another approach might be to use the -fdump-class-hierarchy flag to
get information. However, currently this approach gives insufficient
data for use in library testing, as class data members, their offsets,
and other detailed data is not displayed with this flag.
(See g++/7470 on how this was used to find bugs.)
Perhaps there are other C++ ABI checkers. If so, please notify
us. We'd like to know about them!
Testing Multi-ABI binaries
A "C" application, dynamically linked to two shared libraries, liba,
libb. The dependent library liba is C++ shared library compiled with
gcc-3.3.x, and uses io, exceptions, locale, etc. The dependent library
libb is a C++ shared library compiled with gcc-3.4.x, and also uses io,
exceptions, locale, etc.
As above, libone is constructed as follows:
%$bld/H-x86-gcc-3.4.0/bin/g++ -fPIC -DPIC -c a.cc
%$bld/H-x86-gcc-3.4.0/bin/g++ -shared -Wl,-soname -Wl,libone.so.1 -Wl,-O1 -Wl,-z,defs a.o -o libone.so.1.0.0
%ln -s libone.so.1.0.0 libone.so
%$bld/H-x86-gcc-3.4.0/bin/g++ -c a.cc
%ar cru libone.a a.o
And, libtwo is constructed as follows:
%$bld/H-x86-gcc-3.3.3/bin/g++ -fPIC -DPIC -c b.cc
%$bld/H-x86-gcc-3.3.3/bin/g++ -shared -Wl,-soname -Wl,libtwo.so.1 -Wl,-O1 -Wl,-z,defs b.o -o libtwo.so.1.0.0
%ln -s libtwo.so.1.0.0 libtwo.so
%$bld/H-x86-gcc-3.3.3/bin/g++ -c b.cc
%ar cru libtwo.a b.o
...with the resulting libraries looking like
%ldd libone.so.1.0.0
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x40016000)
libm.so.6 => /lib/tls/libm.so.6 (0x400fa000)
libgcc_s.so.1 => /mnt/hd/bld/gcc/gcc/libgcc_s.so.1 (0x4011c000)
libc.so.6 => /lib/tls/libc.so.6 (0x40125000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x00355000)
%ldd libtwo.so.1.0.0
libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0x40027000)
libm.so.6 => /lib/tls/libm.so.6 (0x400e1000)
libgcc_s.so.1 => /mnt/hd/bld/gcc/gcc/libgcc_s.so.1 (0x40103000)
libc.so.6 => /lib/tls/libc.so.6 (0x4010c000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x00355000)
Then, the "C" compiler is used to compile a source file that uses
functions from each library.
gcc test.c -g -O2 -L. -lone -ltwo /usr/lib/libstdc++.so.5 /usr/lib/libstdc++.so.6
Which gives the expected:
%ldd a.out
libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0x00764000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x40015000)
libc.so.6 => /lib/tls/libc.so.6 (0x0036d000)
libm.so.6 => /lib/tls/libm.so.6 (0x004a8000)
libgcc_s.so.1 => /mnt/hd/bld/gcc/gcc/libgcc_s.so.1 (0x400e5000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x00355000)
This resulting binary, when executed, will be able to safely use code
from both liba, and the dependent libstdc++.so.6, and libb, with the
dependent libstdc++.so.5.
Bibliography / Further Reading
ABIcheck, a vague idea of checking ABI compatibility
http://abicheck.sourceforge.net/
http://abicheck.sourceforge.net/
C++ ABI reference
http://www.codesourcery.com/cxx-abi/
http://www.codesourcery.com/cxx-abi/
Intel ABI documentation, "Intel? Compilers for Linux* -Compatibility with the GNU Compilers"
http://developer.intel.com/software/products/compilers/techtopics/LinuxCompilersCompatibility.htm
http://developer.intel.com/software/products/compilers/techtopics/LinuxCompilersCompatibility.htm
Sun Solaris 2.9 docs
Linker and Libraries Guide (document 816-1386)
C++ Migration Guide (document 816-2459)
http://docs.sun.com/db/prod/solaris.9
http://docs.sun.com/db/prod/solaris.9
http://docs.sun.com/?p=/doc/816-1386&amp;a=load
http://docs.sun.com/?p=/doc/816-1386&a=load
Ulrich Drepper, "ELF Symbol Versioning"
http://people.redhat.com/drepper/symbol-versioning
http://people.redhat.com/drepper/symbol-versioning
