devtools: add ABI checks

For normal developers, those checks are disabled.

Enabling them requires a configuration that will trigger the ABI dumps
generation as part of the existing devtools/test-build.sh and
devtools/test-meson-builds.sh scripts.

Those checks are enabled in the CI for the default meson options on x86
and aarch64 so that proposed patches are validated via our CI robot.
A cache of the ABI is stored in travis jobs to avoid rebuilding too
often.

Checks can be informational only, by setting ABI_CHECKS_WARN_ONLY when
breaking the ABI in a future release.

Explicit suppression rules have been added on internal structures
exposed to crypto drivers as the current ABI policy does not apply to
them.
This could be improved in the future by carefully splitting the headers
content with application and driver "users" in mind.

We currently have issues reported for librte_crypto recent changes for
which suppression rules have been added too.

Mellanox glue libraries are explicitly skipped as they are not part of
the application ABI.

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Luca Boccassi <bluca@debian.org>

.ci/linux-build.sh

@@ -29,6 +29,7 @@ if [ "$BUILD_32BIT" = "1" ]; then
 fi
 
 OPTS="$OPTS --default-library=$DEF_LIB"
+OPTS="$OPTS --buildtype=debugoptimized"
 meson build --werror -Dexamples=all $OPTS
 ninja -C build
 
@@ -36,6 +37,29 @@ if [ "$AARCH64" != "1" ]; then
     devtools/test-null.sh
 fi
 
+if [ "$ABI_CHECKS" = "1" ]; then
+    REF_GIT_REPO=${REF_GIT_REPO:-https://dpdk.org/git/dpdk}
+    REF_GIT_TAG=${REF_GIT_TAG:-v19.11}
+
+    if [ "$(cat reference/VERSION 2>/dev/null)" != "$REF_GIT_TAG" ]; then
+        rm -rf reference
+    fi
+
+    if [ ! -d reference ]; then
+        refsrcdir=$(readlink -f $(pwd)/../dpdk-$REF_GIT_TAG)
+        git clone --single-branch -b $REF_GIT_TAG $REF_GIT_REPO $refsrcdir
+        meson --werror $OPTS $refsrcdir $refsrcdir/build
+        ninja -C $refsrcdir/build
+        DESTDIR=$(pwd)/reference ninja -C $refsrcdir/build install
+        devtools/gen-abi.sh reference
+        echo $REF_GIT_TAG > reference/VERSION
+    fi
+
+    DESTDIR=$(pwd)/install ninja -C build install
+    devtools/gen-abi.sh install
+    devtools/check-abi.sh reference install ${ABI_CHECKS_WARN_ONLY:-}
+fi
+
 if [ "$RUN_TESTS" = "1" ]; then
     sudo meson test -C build --suite fast-tests -t 3
 fi

.travis.yml

@@ -1,5 +1,8 @@
 language: c
-cache: ccache
+cache:
+  ccache: true
+  directories:
+    - reference
 compiler:
   - gcc
   - clang
@@ -21,7 +24,7 @@ aarch64_packages: &aarch64_packages
 
 extra_packages: &extra_packages
   - *required_packages
-  - [libbsd-dev, libpcap-dev, libcrypto++-dev, libjansson4]
+  - [libbsd-dev, libpcap-dev, libcrypto++-dev, libjansson4, abigail-tools]
 
 build_32b_packages: &build_32b_packages
   - *required_packages
@@ -151,5 +154,18 @@ matrix:
         packages:
           - *required_packages
           - *doc_packages
+  - env: DEF_LIB="shared" EXTRA_PACKAGES=1 ABI_CHECKS=1
+    compiler: gcc
+    addons:
+      apt:
+        packages:
+          - *extra_packages
+  - env: DEF_LIB="shared" EXTRA_PACKAGES=1 ABI_CHECKS=1
+    arch: arm64
+    compiler: gcc
+    addons:
+      apt:
+        packages:
+          - *extra_packages
 
 script: ./.ci/${TRAVIS_OS_NAME}-build.sh

MAINTAINERS

@@ -144,8 +144,11 @@ M: Neil Horman <nhorman@tuxdriver.com>
 F: lib/librte_eal/common/include/rte_compat.h
 F: lib/librte_eal/common/include/rte_function_versioning.h
 F: doc/guides/rel_notes/deprecation.rst
+F: devtools/check-abi.sh
 F: devtools/check-abi-version.sh
 F: devtools/check-symbol-change.sh
+F: devtools/gen-abi.sh
+F: devtools/libabigail.abignore
 F: devtools/update-abi.sh
 F: devtools/update_version_map_abi.py
 F: devtools/validate-abi.sh

devtools/check-abi.sh

@@ -0,0 +1,59 @@
+#!/bin/sh -e
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2019 Red Hat, Inc.
+
+if [ $# != 2 ] && [ $# != 3 ]; then
+	echo "Usage: $0 refdir newdir [warnonly]"
+	exit 1
+fi
+
+refdir=$1
+newdir=$2
+warnonly=${3:-}
+ABIDIFF_OPTIONS="--suppr $(dirname $0)/libabigail.abignore --no-added-syms"
+
+if [ ! -d $refdir ]; then
+	echo "Error: reference directory '$refdir' does not exist."
+	exit 1
+fi
+incdir=$(find $refdir -type d -a -name include)
+if [ -z "$incdir" ] || [ ! -e "$incdir" ]; then
+	echo "WARNING: could not identify a include directory for $refdir, expect false positives..."
+else
+	ABIDIFF_OPTIONS="$ABIDIFF_OPTIONS --headers-dir1 $incdir"
+fi
+
+if [ ! -d $newdir ]; then
+	echo "Error: directory to check '$newdir' does not exist."
+	exit 1
+fi
+incdir2=$(find $newdir -type d -a -name include)
+if [ -z "$incdir2" ] || [ ! -e "$incdir2" ]; then
+	echo "WARNING: could not identify a include directory for $newdir, expect false positives..."
+else
+	ABIDIFF_OPTIONS="$ABIDIFF_OPTIONS --headers-dir2 $incdir2"
+fi
+
+error=
+for dump in $(find $refdir -name "*.dump"); do
+	name=$(basename $dump)
+	# skip glue drivers, example librte_pmd_mlx5_glue.dump
+	# We can't rely on a suppression rule for now:
+	# https://sourceware.org/bugzilla/show_bug.cgi?id=25480
+	if [ "$name" != "${name%%_glue.dump}" ]; then
+		echo "Skipping ${dump}..."
+		continue
+	fi
+	dump2=$(find $newdir -name $name)
+	if [ -z "$dump2" ] || [ ! -e "$dump2" ]; then
+		echo "Error: can't find $name in $newdir"
+		error=1
+		continue
+	fi
+	if ! abidiff $ABIDIFF_OPTIONS $dump $dump2; then
+		echo "Error: ABI issue reported for 'abidiff $ABIDIFF_OPTIONS $dump $dump2'"
+		error=1
+	fi
+done
+
+[ -z "$error" ] || [ -n "$warnonly" ]

devtools/gen-abi.sh

@@ -0,0 +1,26 @@
+#!/bin/sh -e
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2019 Red Hat, Inc.
+
+if [ $# != 1 ]; then
+	echo "Usage: $0 installdir"
+	exit 1
+fi
+
+installdir=$1
+if [ ! -d $installdir ]; then
+	echo "Error: install directory '$installdir' does not exist."
+	exit 1
+fi
+
+dumpdir=$installdir/dump
+rm -rf $dumpdir
+mkdir -p $dumpdir
+for f in $(find $installdir -name "*.so.*"); do
+	if test -L $f; then
+		continue
+	fi
+
+	libname=$(basename $f)
+	abidw --out-file $dumpdir/${libname%.so*}.dump $f
+done

devtools/libabigail.abignore

@@ -0,0 +1,13 @@
+[suppress_function]
+        symbol_version = EXPERIMENTAL
+[suppress_variable]
+        symbol_version = EXPERIMENTAL
+
+; Explicit ignore for driver-only ABI
+[suppress_type]
+        name = rte_cryptodev_ops
+; Ignore this enum update as it is part of an experimental API
+[suppress_type]
+        type_kind = enum
+        name = rte_crypto_asym_xform_type
+        changed_enumerators = RTE_CRYPTO_ASYM_XFORM_TYPE_LIST_END

devtools/test-build.sh

@@ -6,6 +6,8 @@ default_path=$PATH
 
 # Load config options:
 # - ARMV8_CRYPTO_LIB_PATH
+# - DPDK_ABI_REF_DIR
+# - DPDK_ABI_REF_VERSION
 # - DPDK_BUILD_TEST_CONFIGS (defconfig1+option1+option2 defconfig2)
 # - DPDK_BUILD_TEST_DIR
 # - DPDK_DEP_ARCHIVE
@@ -30,7 +32,8 @@ default_path=$PATH
 # - LIBSSO_SNOW3G_PATH
 # - LIBSSO_KASUMI_PATH
 # - LIBSSO_ZUC_PATH
-. $(dirname $(readlink -f $0))/load-devel-config
+devtools_dir=$(dirname $(readlink -f $0))
+. $devtools_dir/load-devel-config
 
 print_usage () {
 	echo "usage: $(basename $0) [-h] [-jX] [-s] [config1 [config2] ...]]"
@@ -67,7 +70,8 @@ J=$DPDK_MAKE_JOBS
 builds_dir=${DPDK_BUILD_TEST_DIR:-.}
 short=false
 unset verbose
-maxerr=-Wfatal-errors
+# for ABI checks, we need debuginfo
+test_cflags="-Wfatal-errors -g"
 while getopts hj:sv ARG ; do
 	case $ARG in
 		j ) J=$OPTARG ;;
@@ -97,7 +101,7 @@ trap "signal=INT ; trap - INT ; kill -INT $$" INT
 # notify result on exit
 trap on_exit EXIT
 
-cd $(dirname $(readlink -f $0))/..
+cd $devtools_dir/..
 
 reset_env ()
 {
@@ -233,14 +237,14 @@ for conf in $configs ; do
 	# reload config with DPDK_TARGET set
 	DPDK_TARGET=$target
 	reset_env
-	. $(dirname $(readlink -f $0))/load-devel-config
+	. $devtools_dir/load-devel-config
 
 	options=$(echo $conf | sed 's,[^~+]*,,')
 	dir=$builds_dir/$conf
 	config $dir $target $options
 
 	echo "================== Build $conf"
-	${MAKE} -j$J EXTRA_CFLAGS="$maxerr $DPDK_DEP_CFLAGS" \
+	${MAKE} -j$J EXTRA_CFLAGS="$test_cflags $DPDK_DEP_CFLAGS" \
 		EXTRA_LDFLAGS="$DPDK_DEP_LDFLAGS" $verbose O=$dir
 	! $short || break
 	export RTE_TARGET=$target
@@ -253,6 +257,43 @@ for conf in $configs ; do
 		EXTRA_LDFLAGS="$DPDK_DEP_LDFLAGS" $verbose \
 		O=$(readlink -f $dir)/examples
 	unset RTE_TARGET
+	if [ -n "$DPDK_ABI_REF_VERSION" ]; then
+		abirefdir=${DPDK_ABI_REF_DIR:-reference}/$DPDK_ABI_REF_VERSION
+		if [ ! -d $abirefdir/$conf ]; then
+			# clone current sources
+			if [ ! -d $abirefdir/src ]; then
+				git clone --local --no-hardlinks \
+					--single-branch \
+					-b $DPDK_ABI_REF_VERSION \
+					$(pwd) $abirefdir/src
+			fi
+
+			cd $abirefdir/src
+
+			rm -rf $abirefdir/build
+			config $abirefdir/build $target $options
+
+			echo -n "================== Build $conf "
+			echo "($DPDK_ABI_REF_VERSION)"
+			${MAKE} -j$J \
+				EXTRA_CFLAGS="$test_cflags $DPDK_DEP_CFLAGS" \
+				EXTRA_LDFLAGS="$DPDK_DEP_LDFLAGS" $verbose \
+				O=$abirefdir/build
+			export RTE_TARGET=$target
+			${MAKE} install O=$abirefdir/build \
+				DESTDIR=$abirefdir/$conf \
+				prefix=
+			unset RTE_TARGET
+			$devtools_dir/gen-abi.sh $abirefdir/$conf
+
+			# back to current workdir
+			cd $devtools_dir/..
+		fi
+
+		echo "================== Check ABI $conf"
+		$devtools_dir/gen-abi.sh $dir/install
+		$devtools_dir/check-abi.sh $abirefdir/$conf $dir/install
+	fi
 	echo "################## $conf done."
 	unset dir
 done

devtools/test-meson-builds.sh

@@ -64,9 +64,18 @@ config () # <dir> <builddir> <meson options>
 	builddir=$1
 	shift
 	if [ -f "$builddir/build.ninja" ] ; then
+		# for existing environments, switch to debugoptimized if unset
+		# so that ABI checks can run
+		if ! $MESON configure $builddir |
+				awk '$1=="buildtype" {print $2}' |
+				grep -qw debugoptimized; then
+			$MESON configure --buildtype=debugoptimized $builddir
+		fi
 		return
 	fi
-	options="--werror -Dexamples=all"
+	options=
+	options="$options --werror -Dexamples=all"
+	options="$options --buildtype=debugoptimized"
 	for option in $DPDK_MESON_OPTIONS ; do
 		options="$options -D$option"
 	done
@@ -92,6 +101,13 @@ compile () # <builddir>
 	fi
 }
 
+install_target () # <builddir> <installdir>
+{
+	rm -rf $2
+	echo "DESTDIR=$2 $ninja_cmd -C $1 install"
+	DESTDIR=$2 $ninja_cmd -C $1 install
+}
+
 build () # <directory> <target compiler> <meson options>
 {
 	targetdir=$1
@@ -103,6 +119,31 @@ build () # <directory> <target compiler> <meson options>
 	load_env $targetcc || return 0
 	config $srcdir $builds_dir/$targetdir $*
 	compile $builds_dir/$targetdir
+	if [ -n "$DPDK_ABI_REF_VERSION" ]; then
+		abirefdir=${DPDK_ABI_REF_DIR:-reference}/$DPDK_ABI_REF_VERSION
+		if [ ! -d $abirefdir/$targetdir ]; then
+			# clone current sources
+			if [ ! -d $abirefdir/src ]; then
+				git clone --local --no-hardlinks \
+					--single-branch \
+					-b $DPDK_ABI_REF_VERSION \
+					$srcdir $abirefdir/src
+			fi
+
+			rm -rf $abirefdir/build
+			config $abirefdir/src $abirefdir/build $*
+			compile $abirefdir/build
+			install_target $abirefdir/build $abirefdir/$targetdir
+			$srcdir/devtools/gen-abi.sh $abirefdir/$targetdir
+		fi
+
+		install_target $builds_dir/$targetdir \
+			$(readlink -f $builds_dir/$targetdir/install)
+		$srcdir/devtools/gen-abi.sh \
+			$(readlink -f $builds_dir/$targetdir/install)
+		$srcdir/devtools/check-abi.sh $abirefdir/$targetdir \
+			$(readlink -f $builds_dir/$targetdir/install)
+	fi
 }
 
 if [ "$1" = "-vv" ] ; then
@@ -153,8 +194,11 @@ done
 # Test installation of the x86-default target, to be used for checking
 # the sample apps build using the pkg-config file for cflags and libs
 build_path=$(readlink -f $builds_dir/build-x86-default)
-export DESTDIR=$build_path/install-root
-$ninja_cmd -C $build_path install
+export DESTDIR=$build_path/install
+# No need to reinstall if ABI checks are enabled
+if [ -z "$DPDK_ABI_REF_VERSION" ]; then
+	install_target $build_path $DESTDIR
+fi
 
 load_env cc
 pc_file=$(find $DESTDIR -name libdpdk.pc)

doc/guides/contributing/patches.rst

@@ -513,6 +513,21 @@ in a single subfolder called "__builds" created in the current directory.
 Setting ``DPDK_BUILD_TEST_DIR`` to an absolute directory path e.g. ``/tmp`` is also supported.
 
 
+Checking ABI compatibility
+--------------------------
+
+By default, ABI compatibility checks are disabled.
+
+To enable them, a reference version must be selected via the environment
+variable ``DPDK_ABI_REF_VERSION``.
+
+The ``devtools/test-build.sh`` and ``devtools/test-meson-builds.sh`` scripts
+then build this reference version in a temporary directory and store the
+results in a subfolder of the current working directory.
+The environment variable ``DPDK_ABI_REF_DIR`` can be set so that the results go
+to a different location.
+
+
 Sending Patches
 ---------------