Generate AppImage on GitHub Actions

Fixes #695. Supersedes #172. See https://appimage.org/.

linux/check_dependencies.sh

@@ -0,0 +1,95 @@
+#!/usr/bin/env bash
+
+version="@CPACK_PACKAGE_NAME@ v@CPACK_PACKAGE_VERSION@ @CPACK_AUDACITY_ARCH_LABEL@"
+
+export LC_ALL=C # Using `sort` a lot. Order depends on locale so override it.
+
+# PROBLEM: We want to check dependencies provided by the system, but `ldd`
+# looks in the current directory first so will show other package libraries.
+# SOLUTION: Copy library to temporary folder and test it there.
+function check_file()
+{
+    counter=$(($(cat "$2/.counter")+1))
+    echo ${counter} > "$2/.counter"
+    printf >&2 "Done ${counter} of $3.\r"
+    cp "$1" "$2"
+    file="$(basename "$1")"
+    LANG=C LD_LIBRARY_PATH="" "${APPDIR}/bin/ldd_recursive" -uniq "$2/${file}" 2>/dev/null
+    rm "$2/${file}" # delete library before we test the next one
+}
+export -f check_file # make function available in Bash subprocesses
+
+function prep_result()
+{
+    sed -n "s|$2||p" "$1" | sort -f | tee "$3" | wc -l
+}
+
+if ! which less >/dev/null; then
+    function less() { cat "$@"; } # use `cat` if `less` is unavailable
+fi
+
+tmp="$(mktemp -d)"
+trap "rm -rf '${tmp}'" EXIT
+
+cd "${APPDIR}"
+
+find . -executable -type f \! -name "lib*.so*" > "${tmp}/exes.txt"
+find . -name "lib*.so*"    \! -type l          > "${tmp}/libs.txt"
+
+num_exes="$(<"${tmp}/exes.txt" xargs -n1 basename 2>/dev/null | tee "${tmp}/exes2.txt" | wc -l)"
+num_libs="$(<"${tmp}/libs.txt" xargs -n1 basename 2>/dev/null | tee "${tmp}/libs2.txt" | wc -l)"
+
+echo >&2 "AppImage contains ${num_exes} executables and ${num_libs} libraries."
+
+echo >&2 "Checking dependencies for executables and libraries..."
+include_libs="${tmp}/libs.txt"
+num_includes="$((${num_libs}+${num_exes}))"
+
+# Check dependencies against system. See 'check_file' function.
+echo 0 > "${tmp}/.counter"
+cat "${tmp}/exes.txt" "${include_libs}" | xargs -n1 -I '%%%' bash -c \
+'check_file "${0}" "${1}" "${2}"' "%%%" "${tmp}" "${num_includes}" \; \
+| sort | uniq > "${tmp}/deps.txt"
+echo >&2 "Processing results."
+
+mv "${tmp}/libs2.txt" "${tmp}/libs.txt"
+mv "${tmp}/exes2.txt" "${tmp}/exes.txt"
+
+# Have only checked system libraries. Now consider those in package:
+<"${tmp}/libs.txt" xargs -n1 -I '%%%' sed -i 's|^%%% => not found$|%%% => package|' "${tmp}/deps.txt"
+<"${tmp}/libs.txt" xargs -n1 -I '%%%' sed -i 's|%%%$|%%% => both|' "${tmp}/deps.txt"
+
+# Remaining dependencies must be system:
+sed -ri 's/^(.*[^(not found|package|both)])$/\1 => system/' "${tmp}/deps.txt"
+
+num_package=$(prep_result "${tmp}/deps.txt" ' => package$'   "${tmp}/package.txt")
+num_system=$(prep_result  "${tmp}/deps.txt" ' => system$'    "${tmp}/system.txt")
+num_both=$(prep_result    "${tmp}/deps.txt" ' => both$'      "${tmp}/both.txt")
+num_neither=$(prep_result "${tmp}/deps.txt" ' => not found$' "${tmp}/neither.txt")
+
+# Any libraries included in package that don't appear in 'deps.txt' **might**
+# not actually be needed. Careful: they might be needed by a plugin!
+num_extra=$(<"${tmp}/libs.txt" xargs -n1 -I '%%%' sh -c \
+    "grep -q '%%%' \"${tmp}/deps.txt\" || echo '%%%'" \
+    | sort -f | tee "${tmp}/extra.txt" | wc -l)
+
+less <<EOF
+# Package: ${version}
+# System: $(uname -srmo)
+$(cat /etc/*release*)
+
+# In package only: ${num_package}
+$(cat "${tmp}/package.txt")
+
+# System only: ${num_system}
+$(cat "${tmp}/system.txt")
+
+# Provided by both: ${num_both}
+$(cat "${tmp}/both.txt")
+
+# Provided by neither: ${num_neither}
+$(cat "${tmp}/neither.txt")
+
+# Extra: ${num_extra} (In package but unlinked. Possibly needed by plugins.)
+$(cat "${tmp}/extra.txt")
+EOF