ci: test Valgrind

Using `--trace-children=yes` has a trade-off here, as it makes
`test_scripts.sh` pretty slow when calling various non-xz utilities.

But I also feel like it's not useless to have Valgrind used there and it's
not easy to exclude Valgrind just for that one test...

I did consider using AX_VALGRIND_CHECK [0][1] but I couldn't get it working
immediately with some conditionally-built tests and I wondered if it was
worth spending time on at least while we're debating xz's future build
system situation.

[0] https://www.gnu.org/software/autoconf-archive/ax_valgrind_check.html
[1] https://tecnocode.co.uk/2014/12/23/automatically-valgrinding-code-with-ax_valgrind_check/

.github/workflows/ci.yml

@@ -37,7 +37,7 @@ jobs:
         if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'autotools' }}
         run: |
             sudo apt-get update
-            sudo apt-get install -y autoconf automake build-essential po4a autopoint gcc-multilib doxygen musl-tools
+            sudo apt-get install -y autoconf automake build-essential po4a autopoint gcc-multilib doxygen musl-tools valgrind
 
       # Install Autotools on Mac
       - name: Install Dependencies
@@ -89,6 +89,15 @@ jobs:
             ./build-aux/ci_build.sh -b autotools -p test -f "-fsanitize=address,undefined" -d sandbox
             cd ../xz_build && make distclean
 
+      - name: Build with Valgrind
+        if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'autotools' }}
+        run: ./build-aux/ci_build.sh -b autotools -p build -d sandbox
+      - name: Test with Valgrind
+        if: ${{ matrix.os == 'ubuntu-latest' && matrix.build_system == 'autotools' }}
+        run: |
+            ./build-aux/ci_build.sh -b autotools -p test -d sandbox -w "valgrind --quiet --trace-children=yes --exit-on-first-error=yes --error-exitcode=1"
+            cd ../xz_build && make distclean
+
       - name: Build with musl libc
         if: ${{ matrix.os == 'ubuntu-latest'}}
         run: ./build-aux/ci_build.sh -b ${{ matrix.build_system }} -p build -m "/usr/bin/musl-gcc"

build-aux/ci_build.sh

@@ -53,7 +53,7 @@ ARTIFACTS_DIR_NAME="output"
 # Parse arguments #
 ###################
 
-while getopts a:b:c:d:l:m:n:s:p:f:h opt; do
+while getopts a:b:c:d:l:m:n:s:p:f:w:h opt; do
 	# b option can have either value "autotools" OR "cmake"
 	case ${opt} in
 	h)
@@ -108,6 +108,8 @@ while getopts a:b:c:d:l:m:n:s:p:f:h opt; do
 		CFLAGS="$OPTARG"
 		export CFLAGS
 	;;
+	w) WRAPPER="$OPTARG"
+	;;
 	esac
 done
 
@@ -260,7 +262,7 @@ then
 	autotools)
 		cd "$DEST_DIR"
 		# If the tests fail, copy the test logs into the artifacts folder
-		if make check
+		if make check LOG_COMPILER="$WRAPPER"
 		then
 			:
 		else
@@ -271,7 +273,7 @@ then
 	;;
 	cmake)
 		cd "$DEST_DIR"
-		if make test
+		if ${WRAPPER} make test
 		then
 			:
 		else