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NAME | INVOCATION | ENVIRONMENT | OPTIONS | RETURN VALUE | AUTHOR | COPYRIGHT | COLOPHON |
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ABIPKGDIFF(1) Libabigail ABIPKGDIFF(1)
abipkgdiff - compare ABIs of ELF files in software packages
abipkgdiff compares the Application Binary Interfaces (ABI) of
the ELF binaries contained in two software packages. The
software package formats currently supported are Deb, RPM, tar
archives (either compressed or not) and plain directories that
contain binaries.
For a comprehensive ABI change report that includes changes about
function and variable sub-types, the two input packages must be
accompanied with their debug information packages that contain
debug information either in DWARF, CTF or in BTF formats. Please
note however that some packages contain binaries that embed the
debug information directly in a section of said binaries. In
those cases, obviously, no separate debug information package is
needed as the tool will find the debug information inside the
binaries.
By default, abipkgdiff uses debug information in DWARF format, if
present, otherwise it compares binaries interfaces using debug
information in CTF or in BTF formats, if present. Finally, if no
debug info in these formats is found, it only considers ELF
symbols and report about their addition or removal.
This tool uses the libabigail library to analyze the binary as
well as its associated debug information. Here is its general
mode of operation.
When instructed to do so, a binary and its associated debug
information is read and analyzed. To that effect, libabigail
analyzes by default the descriptions of the types reachable by
the interfaces (functions and variables) that are visible outside
of their translation unit. Once that analysis is done, an
Application Binary Interface Corpus is constructed by only
considering the subset of types reachable from interfaces
associated to ELF symbols that are defined and exported by the
binary. It's that final ABI corpus which libabigail considers as
representing the ABI of the analyzed binary.
Libabigail then has capabilities to generate textual
representations of ABI Corpora, compare them, analyze their
changes and report about them.
abipkgdiff [option] <package1> <package2>
package1 and package2 are the packages that contain the binaries
to be compared.
abipkgdiff loads two default suppression specifications files,
merges their content and use it to filter out ABI change reports
that might be considered as false positives to users.
• Default system-wide suppression specification file
It's located by the optional environment variable
LIBABIGAIL_DEFAULT_SYSTEM_SUPPRESSION_FILE. If that
environment variable is not set, then abipkgdiff tries to load
the suppression file
$libdir/libabigail/libabigail-default.abignore. If that file
is not present, then no default system-wide suppression
specification file is loaded.
• Default user suppression specification file.
It's located by the optional environment
LIBABIGAIL_DEFAULT_USER_SUPPRESSION_FILE. If that environment
variable is not set, then abipkgdiff tries to load the
suppression file $HOME/.abignore. If that file is not present,
then no default user suppression specification is loaded.
In addition to those default suppression specification files,
abipkgdiff will also look inside the packages being compared and
if it sees a file that ends with the extension .abignore, then it
will consider it as a suppression specification and it will
combine it to the default suppression specification that might be
already loaded.
The user might as well use the --suppressions option (that is
documented further below) to provide a suppression specification.
• --help | -h
Display a short help about the command and exit.
• --version | -v
Display the version of the program and exit.
• --debug-info-pkg1 | --d1 <path>
For cases where the debug information for package1 is split
out into a separate file, tells abipkgdiff where to find
that separate debug information package.
Note that the debug info for package1 can have been split
into several different debug info packages. In that case,
several instances of this options can be provided, along
with those several different debug info packages.
• --debug-info-pkg2 | --d2 <path>
For cases where the debug information for package2 is split
out into a separate file, tells abipkgdiff where to find
that separate debug information package.
Note that the debug info for package2 can have been split
into several different debug info packages. In that case,
several instances of this options can be provided, along
with those several different debug info packages.
• --devel-pkg1 | --devel1 <path>
Specifies where to find the Development Package associated
with the first package to be compared. That Development
Package at path should at least contain header files in
which public types exposed by the libraries (of the first
package to be compared) are defined. When this option is
provided, the tool filters out reports about ABI changes to
types that are NOT defined in these header files.
• --devel-pkg2 | --devel2 <path>
Specifies where to find the Development Package associated
with the second package to be compared. That Development
Package at path should at least contains header files in
which public types exposed by the libraries (of the second
package to be compared) are defined. When this option is
provided, the tool filters out reports about ABI changes to
types that are NOT defined in these header files.
• --drop-private-types
This option is to be used with the --devel-pkg1 and
--devel-pkg2 options. With this option, types that are NOT
defined in the headers are entirely dropped from the
internal representation build by Libabigail to represent the
ABI. They thus don't have to be filtered out from the final
ABI change report because they are not even present in
Libabigail's representation.
Without this option however, those private types are kept in
the internal representation and later filtered out from the
report.
This options thus potentially makes Libabigail consume less
memory. It's meant to be mainly used to optimize the memory
consumption of the tool on binaries with a lot of publicly
defined and exported types.
• --dso-only
Compare ELF files that are shared libraries, only. Do not
compare executable files, for instance.
• --private-dso
By default, abipkgdiff does not compare DSOs that are
private to the RPM package. A private DSO is a DSO which
SONAME is NOT advertised in the "provides" property of the
RPM.
This option instructs abipkgdiff to also compare DSOs that
are NOT advertised in the "provides" property of the RPM.
Please note that the fact that (by default) abipkgdiff skips
private DSO is a feature that is available only for RPMs, at
the moment. We would happily accept patches adding that
feature for other package formats.
• --leaf-changes-only|-l only show leaf changes, so don't show
impact analysis report. This option implies --redundant
The typical output of abipkgdiff and abidiff when comparing
two binaries, that we shall call full impact report, looks
like this
$ abidiff libtest-v0.so libtest-v1.so
Functions changes summary: 0 Removed, 1 Changed, 0 Added function
Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
1 function with some indirect sub-type change:
[C]'function void fn(C&)' at test-v1.cc:13:1 has some indirect sub-type changes:
parameter 1 of type 'C&' has sub-type changes:
in referenced type 'struct C' at test-v1.cc:7:1:
type size hasn't changed
1 data member change:
type of 'leaf* C::m0' changed:
in pointed to type 'struct leaf' at test-v1.cc:1:1:
type size changed from 32 to 64 bits
1 data member insertion:
'char leaf::m1', at offset 32 (in bits) at test-v1.cc:4:1
$
So in that example the report emits information about how
the data member insertion change of "struct leaf" is
reachable from function "void fn(C&)". In other words, the
report not only shows the data member change on "struct
leaf", but it also shows the impact of that change on the
function "void fn(C&)".
In abidiff (and abipkgdiff) parlance, the change on "struct
leaf" is called a leaf change. So the --leaf-changes-only
--impacted-interfaces options show, well, only the leaf
change. And it goes like this:
$ abidiff -l libtest-v0.so libtest-v1.so
'struct leaf' changed:
type size changed from 32 to 64 bits
1 data member insertion:
'char leaf::m1', at offset 32 (in bits) at test-v1.cc:4:1
one impacted interface:
function void fn(C&)
$
Note how the report ends up by showing the list of
interfaces impacted by the leaf change. That's the effect
of the additional --impacted-interfaces option.
Now if you don't want to see that list of impacted
interfaces, then you can just avoid using the
--impacted-interface option. You can learn about that
option below, in any case.
Please note that when comparing two Linux Kernel packages,
it's this leaf changes report that is emitted, by default.
The normal so-called full impact report can be emitted with
the option --full-impact which is documented later below.
• --impacted-interfaces
When showing leaf changes, this option instructs abipkgdiff
to show the list of impacted interfaces. This option is
thus to be used in addition to the --leaf-changes-only
option, or, when comparing two Linux Kernel packages.
Otherwise, it's simply ignored.
• --full-impact|-f
When comparing two Linux Kernel packages, this function
instructs abipkgdiff to emit the so-called full impact
report, which is the default report kind emitted by the
abidiff tool:
$ abidiff libtest-v0.so libtest-v1.so
Functions changes summary: 0 Removed, 1 Changed, 0 Added function
Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
1 function with some indirect sub-type change:
[C]'function void fn(C&)' at test-v1.cc:13:1 has some indirect sub-type changes:
parameter 1 of type 'C&' has sub-type changes:
in referenced type 'struct C' at test-v1.cc:7:1:
type size hasn't changed
1 data member change:
type of 'leaf* C::m0' changed:
in pointed to type 'struct leaf' at test-v1.cc:1:1:
type size changed from 32 to 64 bits
1 data member insertion:
'char leaf::m1', at offset 32 (in bits) at test-v1.cc:4:1
$
• --non-reachable-types|-t
Analyze and emit change reports for all the types of the
binary, including those that are not reachable from global
functions and variables.
This option might incur some serious performance degradation
as the number of types analyzed can be huge. However, if
paired with the --devel-pkg{1,2} options, the additional
non-reachable types analyzed are restricted to those defined
in the public headers files carried by the referenced
development packages, thus hopefully making the performance
hit acceptable.
Also, using this option alongside suppression specifications
(by also using the --suppressions option) might help keep
the number of analyzed types (and the potential performance
degradation) in control.
Note that without this option, only types that are reachable
from global functions and variables are analyzed, so the
tool detects and reports changes on these reachable types
only.
• --exported-interfaces-only
By default, when looking at the debug information
accompanying a binary, this tool analyzes the descriptions
of the types reachable by the interfaces (functions and
variables) that are visible outside of their translation
unit. Once that analysis is done, an ABI corpus is
constructed by only considering the subset of types
reachable from interfaces associated to ELF symbols that are
defined and exported by the binary. It's those final ABI
Corpora that are compared by this tool.
The problem with that approach however is that analyzing all
the interfaces that are visible from outside their
translation unit can amount to a lot of data, especially
when those binaries are applications, as opposed to shared
libraries. One example of such applications is the Linux
Kernel. Analyzing massive ABI corpora like these can be
extremely slow.
To mitigate that performance issue, this option allows
libabigail to only analyze types that are reachable from
interfaces associated with defined and exported ELF symbols.
Note that this option is turned on by default when analyzing
the Linux Kernel. Otherwise, it's turned off by default.
• --allow-non-exported-interfaces
When looking at the debug information accompanying a binary,
this tool analyzes the descriptions of the types reachable
by the interfaces (functions and variables) that are visible
outside of their translation unit. Once that analysis is
done, an ABI corpus is constructed by only considering the
subset of types reachable from interfaces associated to ELF
symbols that are defined and exported by the binary. It's
those final ABI Corpora that are compared by this tool.
The problem with that approach however is that analyzing all
the interfaces that are visible from outside their
translation unit can amount to a lot of data, especially
when those binaries are applications, as opposed to shared
libraries. One example of such applications is the Linux
Kernel. Analyzing massive ABI Corpora like these can be
extremely slow.
In the presence of an "average sized" binary however one can
afford having libabigail analyze all interfaces that are
visible outside of their translation unit, using this
option.
Note that this option is turned on by default, unless we are
in the presence of the Linux Kernel.
• --redundant
In the diff reports, do display redundant changes. A
redundant change is a change that has been displayed
elsewhere in a given report.
• --harmless
In the diff report, display only the harmless changes. By
default, the harmless changes are filtered out of the diff
report keep the clutter to a minimum and have a greater
chance to spot real ABI issues.
• --no-linkage-name
In the resulting report, do not display the linkage names of
the added, removed, or changed functions or variables.
• --no-added-syms
Do not show the list of functions, variables, or any symbol
that was added.
• --no-added-binaries
Do not show the list of binaries that got added to the
second package.
Please note that the presence of such added binaries is not
considered like an ABI change by this tool; as such, it
doesn't have any impact on the exit code of the tool. It
does only have an informational value. Removed binaries
are, however, considered as an ABI change.
• --no-abignore
Do not search the package for the presence of suppression
files.
• --no-parallel
By default, abipkgdiff will use all the processors it has
available to execute concurrently. This option tells it not
to extract packages or run comparisons in parallel.
• --no-default-suppression
Do not load the default suppression specification 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. In that case, all of
the suppression specification files are taken into account.
Please note that, by default, if this option is not
provided, then the default suppression specification files
are loaded .
• --linux-kernel-abi-whitelist | -w <path-to-whitelist>
When comparing two Linux kernel RPM packages, this option
points to the white list of names of ELF symbols of
functions and variables that must be compared for ABI
changes. That white list is called a "Linux kernel ABI
white list".
Any other function or variable which ELF symbol are not
present in that white list will not be considered by the ABI
comparison process.
If this option is not provided -- thus if no white list is
provided -- then the ABI of all publicly defined and
exported functions and global variables by the Linux Kernel
binaries are compared.
Please note that if a white list package is given in
parameter, this option handles it just fine, like if the
--wp option was used.
• --wp <path-to-whitelist-package>
When comparing two Linux kernel RPM packages, this option
points an RPM package containining several white lists of
names of ELF symbols of functions and variables that must be
compared for ABI changes. Those white lists are called
"Linux kernel ABI white lists".
From the content of that white list package, this program
then chooses the appropriate Linux kernel ABI white list to
consider when comparing the ABI of Linux kernel binaries
contained in the Linux kernel packages provided on the
command line.
That choosen Linux kernel ABI white list contains the list
of names of ELF symbols of functions and variables that must
be compared for ABI changes.
Any other function or variable which ELF symbol are not
present in that white list will not be considered by the ABI
comparison process.
Note that this option can be provided twice (not mor than
twice), specifying one white list package for each Linux
Kernel package that is provided on the command line.
If this option is not provided -- thus if no white list is
provided -- then the ABI of all publicly defined and
exported functions and global variables by the Linux Kernel
binaries are compared.
• --no-unreferenced-symbols
In the resulting report, do not display change information
about function and variable symbols that are not referenced
by any debug information. Note that for these symbols not
referenced by any debug information, the change information
displayed is either added or removed symbols.
• --no-show-locs
Do not show information about where in the second shared
library the respective type was changed.
• --show-bytes
Show sizes and offsets in bytes, not bits. By default,
sizes and offsets are shown in bits.
• --show-bits
Show sizes and offsets in bits, not bytes. This option is
activated by default.
• --show-hex
Show sizes and offsets in hexadecimal base.
• --show-dec
Show sizes and offsets in decimal base. This option is
activated by default.
• --no-show-relative-offset-changes
Without this option, when the offset of a data member
changes, the change report not only mentions the older and
newer offset, but it also mentions by how many bits the data
member changes. With this option, the latter is not shown.
• --show-identical-binaries
Show the names of the all binaries compared, including the
binaries whose ABI compare equal. By default, when this
option is not provided, only binaries with ABI changes are
mentionned in the output.
• --fail-no-dbg
Make the program fail and return a non-zero exit code if
couldn't read any of the debug information that comes from
the debug info packages that were given on the command line.
If no debug info package were provided on the command line
then this option is not active.
Note that the non-zero exit code returned by the program as
a result of this option is the constant ABIDIFF_ERROR. To
know the numerical value of that constant, please refer to
the exit code documentation.
• --keep-tmp-files
Do not erase the temporary directory files that are created
during the execution of the tool.
• --verbose
Emit verbose progress messages.
• --self-check
This is used to test the underlying Libabigail library.
When in used, the command expects only on input package,
along with its associated debug info packages. The command
then compares each binary inside the package against its own
ABIXML representation. The result of the comparison should
yield the empty set if Libabigail behaves correctly.
Otherwise, it means there is an issue that ought to be
fixed. This option is used by people interested in
Libabigail development for regression testing purposes.
Here is an example of the use of this option:
$ abipkgdiff --self-check --d1 mesa-libGLU-debuginfo-9.0.1-3.fc33.x86_64.rpm mesa-libGLU-9.0.1-3.fc33.x86_64.rpm
==== SELF CHECK SUCCEEDED for 'libGLU.so.1.3.1' ====
$
• --no-assume-odr-for-cplusplus
When analysing a binary originating from C++ code using
DWARF debug information, libabigail assumes the One
Definition Rule to speed-up the analysis. In that case,
when several types have the same name in the binary, they
are assumed to all be equal.
This option disables that assumption and instructs
libabigail to actually actually compare the types to
determine if they are equal.
• --no-leverage-dwarf-factorization
When analysing a binary which DWARF debug information was
processed with the DWZ tool, the type information is
supposed to be already factorized. That context is used by
libabigail to perform some speed optimizations.
This option disables those optimizations.
• --ctf
This is used to compare packages with CTF debug
information, if present.
• --btf
This is used to compare packages with BTF debug
information, if present.
The exit code of the abipkgdiff command is either 0 if the ABI of
the binaries compared are equal, or non-zero if they differ or if
the tool encountered an error.
In the later case, the value of the exit code is the same as for
the abidiff tool.
Dodji Seketeli
2014-2022, Red Hat, Inc.
This page is part of the libabigail (ABI Generic Analysis and
Instrumentation Library) project. Information about the project
can be found at ⟨https://sourceware.org/libabigail/⟩. If you
have a bug report for this manual page, see
⟨http://sourceware.org/bugzilla/enter_bug.cgi?product=libabigail⟩.
This page was obtained from the project's upstream Git repository
⟨git://sourceware.org/git/libabigail.git⟩ on 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2024-05-31.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
Jun 14, 2024 ABIPKGDIFF(1)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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