Add use of libabigail for ABI checks

Added `make -C src check-abi` target to leverage libabigail 2.0 tools to
check for ABI changes.

Add ABI baseline files for aarch64, i686, riscv, s390x, and x86_64 Linux
targets and aarch64 and x86_64 QNX SDP 7.1 targets.

Used the check-abi target in the CI-unix github workflow.

.github/workflows/CI-unix.yml

@@ -42,36 +42,43 @@ jobs:
         if: ${{ matrix.target.arch }} = 'i686'
         run: |
           sudo apt update
-          sudo apt install -y g++-12-multilib
+          sudo apt install -y g++-12-multilib abigail-tools
 
       - name: Configure
         run: |
           set -x
           autoreconf -i
-          ./configure --build=x86_64-pc-linux-gnu --host=${{ matrix.target.triple }}
+          mkdir build
+          cd build
+          ../configure --build=x86_64-pc-linux-gnu --host=${{ matrix.target.triple }}
         env:
           CC: ${{ matrix.toolchain.CC }}
           CXX: ${{ matrix.toolchain.CXX }}
-          CFLAGS: "${{ matrix.target.CFLAGS }} ${{ matrix.optimization.CFLAGS }} -Wall -Wextra"
-          CXXFLAGS: "${{ matrix.target.CFLAGS }} ${{ matrix.optimization.CFLAGS }} -Wall -Wextra"
+          CFLAGS: "${{ matrix.target.CFLAGS }} ${{ matrix.optimization.CFLAGS }} -g -Wall -Wextra"
+          CXXFLAGS: "${{ matrix.target.CFLAGS }} ${{ matrix.optimization.CFLAGS }} -g -Wall -Wextra"
           LDFLAGS: ${{ matrix.target.CFLAGS }}
 
       - name: Build
         run: |
-          make -j8
+          make -C build -j
+
+      - name: Check ABI
+        if: ${{ success() }}
+        run:
+          make -C build/src abi-check
 
       - name: Test (native)
         if: ${{ success() }}
         run: |
           set -x
           sudo bash -c 'echo core.%p.%p > /proc/sys/kernel/core_pattern'
           ulimit -c unlimited
-          make check -j8
+          make -C build check -j8
 
       - name: Show Logs
         if: ${{ failure() }}
         run: |
-          cat tests/test-suite.log 2>/dev/null
+          cat build/tests/test-suite.log 2>/dev/null
 
   build-gnu-cross:
     runs-on: ubuntu-22.04
@@ -109,42 +116,58 @@ jobs:
       - name: Install ${{ matrix.config.host }} Toolchain
         run: |
           sudo apt update
-          sudo apt install g++-${{ matrix.config.gccver }}-${{ matrix.config.host }} -y
+          sudo apt install -y g++-${{ matrix.config.gccver }}-${{ matrix.config.host }} abigail-tools
 
       - name: Configure with ${{ matrix.config.cc }}
         run: |
           set -x
           autoreconf -i
-          BUILD=x86_64-linux-gnu
-          ./configure --build=$BUILD --host=${{ matrix.config.host }} --with-testdriver="$(pwd)/libtool execute $(pwd)/scripts/qemu-test-driver" --enable-debug
+          mkdir build
+          cd build
+          ../configure --build=$(config/config.guess) \
+                       --host=${{ matrix.config.host }} \
+                       --with-testdriver="$(pwd)/libtool execute $(pwd)/../scripts/qemu-test-driver" \
+                       --enable-debug
         env:
           CC: ${{ matrix.config.host }}-gcc-${{ matrix.config.gccver }}
           CXX: ${{ matrix.config.host }}-g++-${{ matrix.config.gccver }}
 
       - name: Build
         run: |
-          make -j8
+          make -C build -j
         env:
-          CFLAGS: "-Wall -Wextra"
+          CFLAGS: "-Wall -Wextra -g -Og"
 
       - name: ABI Check
         run: |
-            cd tests && ./check-namespace.sh
+            case ${{ matrix.config.target }} in
+            aarch64|riscv*|s390x|x86*)
+                make -C build/src abi-check
+                ;;
+            *)
+                srcdir=$(pwd)
+                cd build/tests
+                ${srcdir}/tests/run-check-namespace
+                ;;
+            esac
 
       - name: Test
         run: |
           set -x
           sudo bash -c 'echo core.%p.%p > /proc/sys/kernel/core_pattern'
           ulimit -c unlimited
-          CROSS_LIB="/usr/${{ matrix.config.host }}"
-          make check LOG_DRIVER_FLAGS="--qemu-arch ${{ matrix.config.qemu }}" QEMU_LD_PREFIX="$CROSS_LIB"
+          cd build
+          make check LOG_DRIVER_FLAGS="--qemu-arch ${{ matrix.config.qemu }}" \
+                     QEMU_LD_PREFIX="$CROSS_LIB" \
+                     LDFLAGS="-L$CROSS_LIB/lib"
         env:
           UNW_DEBUG_LEVEL: 4
+          CROSS_LIB: "/usr/${{ matrix.config.host }}"
 
       - name: Show Logs
         if: ${{ failure() }}
         run: |
-          cat tests/test-suite.log 2>/dev/null
+          cat build/tests/test-suite.log 2>/dev/null
 
   build-musl-native:
     runs-on: ubuntu-latest

Makefile.am

@@ -121,3 +121,6 @@ MAINTAINERCLEANFILES = \
 	include/config.h.in \
 	include/config.h.in~
 
+abi-check:
+	cd src && $(MAKE) $(AM_MAKEFLAGS) $@
+

configure.ac

@@ -541,6 +541,20 @@ if test x$have__builtin_unreachable = xyes; then
 fi
 AC_MSG_RESULT([$have__builtin_unreachable])
 
+AC_CHECK_TOOL([ABICHECK], [abidw])
+AS_IF([test "$ABICHECK" = ":"],, [
+    abicheck_version=$($ABICHECK --version | sed -n 's/[[^ ]]* \([[0-9]]\).*/\1/p')
+    AC_MSG_WARN([$ABICHECK version $abicheck_version])
+    AS_IF([test $abicheck_version -ge 2],
+          [ABIDIFF=abidiff],
+          [AC_MSG_WARN([$ABICHECK is version $abicheck_version, need at least 2.0])
+           ABICHECK=":"
+           ABIDIFF=":"]
+    )
+])
+AC_SUBST(ABICHECK)
+AC_SUBST(ABIDIFF)
+
 arch="$target_arch"
 ARCH=`echo $target_arch | tr [a-z] [A-Z]`
 

src/Makefile.am

@@ -1251,10 +1251,46 @@ libunwind_la_LIBADD += $(LIBLZMA) $(LIBZ)
 
 noinst_HEADERS += unwind/unwind-internal.h
 
-EXTRA_DIST = $(libunwind_la_EXTRAS_ia64)
+EXTRA_DIST = $(libunwind_la_EXTRAS_ia64) abi
 
 MAINTAINERCLEANFILES = Makefile.in
 
+#
+# ABI checks
+#
+# Running the ABI checks require configuring with CFLAGS="-g -Og".
+# The result is output in a file with the `.abidiff` extension which is also
+# printed to stdout if there is an ABI mismatch detected.
+#
+# This also requires libabigail tools of at least version 2.0 to be installed.
+#
+.la.abi:
+	$(AM_V_GEN)soname=$$(sed -n -e "s#dlname='\(.*\)\.[0-9]*'#\1#p" $<); \
+	if test -n "$$soname"; then \
+		$(ABICHECK) .libs/$${soname} \
+		            --no-show-locs \
+		            --no-comp-dir-path \
+		            --no-corpus-path \
+		            --drop-undefined-syms \
+		            --drop-private-types \
+		            --out-file $@; \
+	else \
+		printf "(no SONAME found in %s)\n" "$<"; \
+	fi
+
+abi_srcdir = "$(top_srcdir)/src/abi"
+abi_targetdir = "$(abi_srcdir)/$(arch)/$(target_os)"
+.abi.abidiff:
+	$(AM_V_GEN)if test -f "$<"; then \
+		$(ABIDIFF) --suppressions "$(abi_srcdir)/libunwind.supp" \
+		           -l "$(abi_targetdir)/$<" "$<" >$@ \
+			|| cat $@; \
+	fi
+
+abi-check: $(lib_LTLIBRARIES:.la=.abidiff) 
+
+.PHONY: abi-check
+
 # The -version-info flag accepts an argument of the form
 # `current[:revision[:age]]'. So, passing `-version-info 3:12:1' sets
 # current to 3, revision to 12, and age to 1.

src/abi/README.md

@@ -0,0 +1,33 @@
+ABI Baseline Files
+==================
+
+This source directory contains the ABI baseline files used to detect
+incompatible ABI (application binary interface) changes in libunwind.
+
+These files are generated using the **libabigail** ABI generic analysis and
+instrumentation library tools https://sourceware.org/libabigail/
+
+Checking the ABI
+----------------
+
+1. Install the **libabigail** tools, at least version 2.0.
+   On Ubuntu you can use the following command
+    ```
+    $ sudo apt install abigail-tools
+    ```
+    and a similar command with other package managers or you can clone the project
+    from upstream and build it yourself.
+
+2. Configure and build libunwind
+    ```
+    $ mkdir build; cd build
+    $ ../configure CFLAGS="-g -Og"
+    $ make -j
+    ```
+
+3. Run the ABI checks
+    ```
+    $ make -C src abi-check
+    ```
+    A report for each .so file will be generated into the corresponding .abidiff
+    file in the build-tree's src directory.