Provided by: abigail-tools_1.2-1_amd64 
NAME
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 in DWARF format.
INVOCATION
abipkgdiff [option] <package1> <package2>
package1 and package2 are the packages that contain the binaries to be compared.
ENVIRONMENT
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.
OPTIONS
• --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.
• --leaf-changes-only|-l only show leaf changes, so don’t show impact analysis report.
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
$
• --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.
• --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.
RETURN VALUE
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.
AUTHOR
Dodji Seketeli
COPYRIGHT
2014-2018, Red Hat, Inc.
Apr 24, 2018 ABIPKGDIFF(1)