[dpdk-dev] [PATCH v3 4/4] add ABI checks

[David Marchand <david.marchand@redhat.com>]

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 only informational 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>
---
Changelog since v2:
- forced -g / buildtype=debugoptimised in the test scripts so that
  we can check ABI in existing environments,
- little update on the documentation,

Changelog since v1:
- reworked the scripts so that the build test scripts clone and build the
  reference automatically. A developer only needs to set one variable to
  enable the checks,
- meson builds are done with debug so that abidiff can inspect the
  structures,
- abidiff checks only public types by looking at installed headers,
- abidiff has some issue when comparing a dump with a .so built with clang
  so all diff are now done with dump files only,
- suppression rules have been added to waive warnings on exposed internal
  types,
- an abi breakage has been reported on changes in cryptodev.
  For now, suppression rules have been put in place to let the CI run,

---
 .ci/linux-build.sh                  | 23 +++++++++++
 .travis.yml                         | 20 +++++++++-
 MAINTAINERS                         |  2 +
 devtools/check-abi.sh               | 59 +++++++++++++++++++++++++++++
 devtools/dpdk.abignore              | 21 ++++++++++
 devtools/gen-abi.sh                 | 26 +++++++++++++
 devtools/test-build.sh              | 51 ++++++++++++++++++++++---
 devtools/test-meson-builds.sh       | 37 +++++++++++++++++-
 doc/guides/contributing/patches.rst | 15 ++++++++
 9 files changed, 246 insertions(+), 8 deletions(-)
 create mode 100755 devtools/check-abi.sh
 create mode 100644 devtools/dpdk.abignore
 create mode 100755 devtools/gen-abi.sh

diff --git a/.ci/linux-build.sh b/.ci/linux-build.sh
index e61aa2b0a..95bd869c3 100755
--- a/.ci/linux-build.sh
+++ b/.ci/linux-build.sh
@@ -30,6 +30,7 @@ fi
 
 OPTS="$OPTS --default-library=$DEF_LIB"
 OPTS="$OPTS --prefix=/usr -Dlibdir=lib"
+OPTS="$OPTS --buildtype=debugoptimized"
 meson build --werror -Dexamples=all $OPTS
 ninja -C build
 DESTDIR=$(pwd)/install ninja -C build install
@@ -40,6 +41,28 @@ if [ "$AARCH64" != "1" ]; then
     unset LD_LIBRARY_PATH
 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
+
+    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
diff --git a/.travis.yml b/.travis.yml
index 8162f1c05..22539d823 100644
--- a/.travis.yml
+++ b/.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
diff --git a/MAINTAINERS b/MAINTAINERS
index 94bccae6d..6dae4ee63 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -144,8 +144,10 @@ 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/update-abi.sh
 F: devtools/update_version_map_abi.py
 F: devtools/validate-abi.sh
diff --git a/devtools/check-abi.sh b/devtools/check-abi.sh
new file mode 100755
index 000000000..5872499ec
--- /dev/null
+++ b/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)/dpdk.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" ]
diff --git a/devtools/dpdk.abignore b/devtools/dpdk.abignore
new file mode 100644
index 000000000..f2903612c
--- /dev/null
+++ b/devtools/dpdk.abignore
@@ -0,0 +1,21 @@
+[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
+
+; FIXME
+[suppress_type]
+        type_kind = enum
+        name = rte_crypto_aead_algorithm
+        changed_enumerators = RTE_CRYPTO_AEAD_LIST_END
+[suppress_variable]
+        name = rte_crypto_aead_algorithm_strings
diff --git a/devtools/gen-abi.sh b/devtools/gen-abi.sh
new file mode 100755
index 000000000..c44b0e228
--- /dev/null
+++ b/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 $f
+done
diff --git a/devtools/test-build.sh b/devtools/test-build.sh
index 52305fbb8..a97e1280e 100755
--- a/devtools/test-build.sh
+++ b/devtools/test-build.sh
@@ -30,7 +30,8 @@ default_path=$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] ...]]"
@@ -64,10 +65,12 @@ print_help () {
 [ -z $MAKE ] && echo "Cannot find make or gmake" && exit 1
 
 J=$DPDK_MAKE_JOBS
+refsrcdir=$(mktemp -d -t dpdk-${DPDK_ABI_REF_VERSION:-}.XXX)
 builds_dir=${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 ;;
@@ -91,13 +94,14 @@ on_exit ()
 		[ "$DPDK_NOTIFY" != notify-send ] || \
 			notify-send -u low --icon=dialog-error 'DPDK build' 'failed'
 	fi
+	rm -rf $refsrcdir
 }
 # catch manual interrupt to ignore notification
 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
+		DPDK_ABI_REF_DIR=${DPDK_ABI_REF_DIR:-reference}
+		abirefdir=$DPDK_ABI_REF_DIR/$DPDK_ABI_REF_VERSION/$conf
+		if [ ! -d $abirefdir ]; then
+			# clone current sources
+			if [ ! -d $refsrcdir/.git ]; then
+				git clone --local --no-hardlinks \
+					--single-branch \
+					-b $DPDK_ABI_REF_VERSION \
+					$(pwd) $refsrcdir
+			fi
+
+			cd $refsrcdir
+
+			rm -rf build
+			config 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=build
+			! $short || break
+			export RTE_TARGET=$target
+			${MAKE} install O=build DESTDIR=$abirefdir \
+				prefix=
+			$devtools_dir/gen-abi.sh $abirefdir
+
+			# 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 $dir/install
+	fi
 	echo "################## $conf done."
 	unset dir
 done
diff --git a/devtools/test-meson-builds.sh b/devtools/test-meson-builds.sh
index 747fb4a1a..23e93770d 100755
--- a/devtools/test-meson-builds.sh
+++ b/devtools/test-meson-builds.sh
@@ -16,8 +16,15 @@ srcdir=$(dirname $(readlink -f $0))/..
 
 MESON=${MESON:-meson}
 use_shared="--default-library=shared"
+refsrcdir=$(mktemp -d -t dpdk-${DPDK_ABI_REF_VERSION:-}.XXX)
 builds_dir=${DPDK_BUILD_TEST_DIR:-.}
 
+on_exit ()
+{
+	rm -rf $refsrcdir
+}
+trap on_exit EXIT
+
 if command -v gmake >/dev/null 2>&1 ; then
 	MAKE=gmake
 else
@@ -64,9 +71,14 @@ config () # <dir> <builddir> <meson options>
 	builddir=$1
 	shift
 	if [ -f "$builddir/build.ninja" ] ; then
+		# for existing environments, force debugoptimized so that ABI
+		# checks can run
+		$MESON configure --buildtype=debugoptimized $builddir
 		return
 	fi
-	options="--werror -Dexamples=all -Dlibdir=lib"
+	options=
+	options="$options --werror -Dexamples=all -Dlibdir=lib"
+	options="$options --buildtype=debugoptimized"
 	for option in $DPDK_MESON_OPTIONS ; do
 		options="$options -D$option"
 	done
@@ -107,6 +119,29 @@ build () # <directory> <target compiler> <meson options>
 	config $srcdir $builds_dir/$targetdir $*
 	compile $builds_dir/$targetdir \
 		$(readlink -f $builds_dir/$targetdir/install)
+	if [ -n "$DPDK_ABI_REF_VERSION" ]; then
+		DPDK_ABI_REF_DIR=${DPDK_ABI_REF_DIR:-reference}
+		abirefdir=$DPDK_ABI_REF_DIR/$DPDK_ABI_REF_VERSION/$targetdir
+		if [ ! -d $abirefdir ]; then
+			# clone current sources
+			if [ ! -d $refsrcdir/.git ]; then
+				git clone --local --no-hardlinks \
+					--single-branch \
+					-b $DPDK_ABI_REF_VERSION \
+					$srcdir $refsrcdir
+			fi
+
+			rm -rf $refsrcdir/build
+			config $refsrcdir $refsrcdir/build $*
+			compile $refsrcdir/build $abirefdir
+			$srcdir/devtools/gen-abi.sh $abirefdir
+		fi
+
+		$srcdir/devtools/gen-abi.sh \
+			$(readlink -f $builds_dir/$targetdir/install)
+		$srcdir/devtools/check-abi.sh $abirefdir \
+			$(readlink -f $builds_dir/$targetdir/install)
+	fi
 }
 
 if [ "$1" = "-vv" ] ; then
diff --git a/doc/guides/contributing/patches.rst b/doc/guides/contributing/patches.rst
index 0686450e4..59442824a 100644
--- a/doc/guides/contributing/patches.rst
+++ b/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
 ---------------
 
-- 
2.23.0