configure: Handle having no c++ compiler in FORTIFY_SOURCE check

Our FORTIFY_SOURCE check assumes that $cxx refers to a working C++
compiler, with the result that if you don't happen to have one
then configure will spuriously print
  configure: line 4685: c++: command not found

Fix this by adding a 'has $cxx' check.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Peter Maydell 2017-06-26 16:25:24 +01:00 committed by Michael Tokarev
parent 667675623d
commit e189091fba

2
configure vendored
View File

@ -4771,7 +4771,7 @@ fi
if test "$fortify_source" != "no"; then
if echo | $cc -dM -E - | grep __clang__ > /dev/null 2>&1 ; then
fortify_source="no";
elif test -n "$cxx" &&
elif test -n "$cxx" && has $cxx &&
echo | $cxx -dM -E - | grep __clang__ >/dev/null 2>&1 ; then
fortify_source="no";
else