+printf "int main(void){return 0;}\n" > minimal.c
+
+printf "Sanity checking C compilation environment... "
+if ${CC} ${CFLAGS} ${CPPFLAGS} minimal.c ${LDFLAGS} -o minimal > /dev/null 2>&1
+then
+ printf "OK.\n"
+else
+ printf "Fail.\n"
+ errors=$((errors + 1))
+fi
+
+printf "Sanity checking C++ compilation environment... "
+if ${CXX} ${CXXFLAGS_for_sh} ${CPPFLAGS} minimal.c ${LDFLAGS} -o minimal > /dev/null 2>&1
+then
+ printf "OK.\n"
+else
+ printf "Fail.\n"
+ errors=$((errors + 1))
+fi
+
+if [ $errors -gt 0 ]; then
+ cat <<EOF
+*** Error: Initial sanity checking of environment failed. Please try
+running configure in a clean environment, and if the problem persists,
+report a bug.
+EOF
+ rm -f minimal minimal.c
+ exit 1
+fi