The ./configure script should produce --help output even if Python is not installed.
Listing trace backends is simple: show the names of all Python modules in scripts/tracetool/backend/ whose source code contains 'PUBLIC = True'. Perform the backend enumeration in shell instead of Python so that we can move the Python check until after ./configure --help. Reported-by: Peter Maydell <peter.mayd...@linaro.org> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> Reviewed-by: Peter Maydell <peter.mayd...@linaro.org> Message-id: 20170328134418.3426-1-stefa...@redhat.com Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- configure | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/configure b/configure index be4d326..6db3044 100755 --- a/configure +++ b/configure @@ -1191,21 +1191,6 @@ for opt do esac done -if ! has $python; then - error_exit "Python not found. Use --python=/path/to/python" -fi - -# Note that if the Python conditional here evaluates True we will exit -# with status 1 which is a shell 'false' value. -if ! $python -c 'import sys; sys.exit(sys.version_info < (2,6) or sys.version_info >= (3,))'; then - error_exit "Cannot use '$python', Python 2.6 or later is required." \ - "Note that Python 3 or later is not yet supported." \ - "Use --python=/path/to/python to specify a supported Python." -fi - -# Suppress writing compiled files -python="$python -B" - case "$cpu" in ppc) CPU_CFLAGS="-m32" @@ -1280,6 +1265,9 @@ for config in $mak_wilds; do default_target_list="${default_target_list} $(basename "$config" .mak)" done +# Enumerate public trace backends for --help output +trace_backend_list=$(echo $(grep -le '^PUBLIC = True$' scripts/tracetool/backend/*.py | sed -e 's/^.*\/\(.*\)\.py$/\1/')) + if test x"$show_help" = x"yes" ; then cat << EOF @@ -1333,7 +1321,7 @@ Advanced options (experts only): set block driver read-only whitelist (affects only QEMU, not qemu-img) --enable-trace-backends=B Set trace backend - Available backends: $($python $source_path/scripts/tracetool.py --list-backends) + Available backends: $trace_backend_list --with-trace-file=NAME Full PATH,NAME of file to store traces Default:trace-<pid> --disable-slirp disable SLIRP userspace network connectivity @@ -1433,6 +1421,21 @@ EOF exit 0 fi +if ! has $python; then + error_exit "Python not found. Use --python=/path/to/python" +fi + +# Note that if the Python conditional here evaluates True we will exit +# with status 1 which is a shell 'false' value. +if ! $python -c 'import sys; sys.exit(sys.version_info < (2,6) or sys.version_info >= (3,))'; then + error_exit "Cannot use '$python', Python 2.6 or later is required." \ + "Note that Python 3 or later is not yet supported." \ + "Use --python=/path/to/python to specify a supported Python." +fi + +# Suppress writing compiled files +python="$python -B" + # Now we have handled --enable-tcg-interpreter and know we're not just # printing the help message, bail out if the host CPU isn't supported. if test "$ARCH" = "unknown"; then -- 2.9.3