Checking for changes in Application Binary Interface, or ABI, may be a good idea for a couple of reasons:
- Upstream does not maintain a soname with version.
- Upstream is not good about maintaining proper ABI compatibility.
It's important to note that a library's ABI can change even if the API does not. This can happen with internal changes to the compiler and/or compiler flags.
# yum install abi-compliance-checker
abi-compliance-checker has a lot of options and while it's not difficult to use it's not necessarily intuitive either. This example is one way to use the tool and should be considered the best practice.
Step 1: Preparing
First you need to unpack the packages to a location. You can use the these commands directly or add these to a shell script which will be called
#!/bin/bash if [ ! -n "$1" ] then echo "Unpacks an RPM into the current directory." echo "" echo "Usage: `basename $0` <package1> [package2]..." fi for file in $*; do rpm2cpio $file | cpio -idmv done
Now create a directory structure and unpack the packages:
$ mkdir -p <package_name>/<version_old> $ mkdir -p <package_name>/<version_new> $ cd <package_name>/<version_old> $ rpmunpack <package>-<version_old> <package>-<version_old>-devel $ cd ../<package_name>/<version_new> $ rpmunpack <package>-<version_new> <package>-<version_new>-devel $ cd ..
Step 2: Dump the ABIs to a file
abi-compliance-checker will assign the version based on the directories created previously. If it doesn't get it right use the
-vnum option to override it.
Execute the following command for both packages:
$ abi-compliance-checker -l <package> -dump <path to unpacked RPM>
-l option needs to stay the same for all operations and is the name used in the resultant html report.
Step 3: Compare the to ABI dumps
The ABI dumps will be created in a sub-directory of where
abi-compliance-checker was run,
abi_dumps/<package>. To compare the to ABI dumps:
$ abi-compliance-checker -l <package> -old abi_dumps/<package>/<package>_<version_old>.abi.tar.gz -new abi_dumps/<package>/<package>_<version_old>.abi.tar.gz
The html report will be created in a directory under
Tips & Tricks
ABI dumps error out
This often happens when upstream installs headers for other platforms. Adding the
-tolerant option can often work around this problem. As a last resort, simply look through the log and remove the offending header.