(AC_FUNC_ALLOCA): Throw an error if a system implementation of alloca

is not found.

diff --git a/configure.in b/configure.in
index c873a29002006c1df17b8d92abf19b89f9fa7d31..306f8441973fb63c94b56915e42bf405fbff772c 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -2692,6 +2692,13 @@ fi
 
 AC_FUNC_ALLOCA
 
+dnl src/alloca.c has been removed.  Could also check if $ALLOCA is set?
+dnl FIXME is there an autoconf test that does the right thing, without
+dnl needing to call A_M_E afterwards?
+if test x"$ac_cv_func_alloca_works" != xyes; then
+   AC_MSG_ERROR( [a system implementation of alloca is required] )
+fi
+
 # fmod, logb, and frexp are found in -lm on most systems.
 # On HPUX 9.01, -lm does not contain logb, so check for sqrt.
 AC_CHECK_LIB(m, sqrt)