1 files changed, 68 insertions, 0 deletions
diff --git a/config/ac-macros/alloca.m4 b/config/ac-macros/alloca.m4
new file mode 100644
index 00000000000..8c730dd671f
--- /dev/null
+++ b/config/ac-macros/alloca.m4
@@ -0,0 +1,68 @@
+AC_DEFUN([MYSQL_FUNC_ALLOCA],
+[
+# Since we have heard that alloca fails on IRIX never define it on a
+# SGI machine
+if test ! "$host_vendor" = "sgi"
+then
+ AC_REQUIRE_CPP()dnl Set CPP; we run AC_EGREP_CPP conditionally.
+ # The Ultrix 4.2 mips builtin alloca declared by alloca.h only works
+ # for constant arguments.  Useless!
+ AC_CACHE_CHECK([for working alloca.h], ac_cv_header_alloca_h,
+ [AC_TRY_LINK([#include <alloca.h>], [char *p = alloca(2 * sizeof(int));],
+   ac_cv_header_alloca_h=yes, ac_cv_header_alloca_h=no)])
+ if test "$ac_cv_header_alloca_h" = "yes"
+ then
+	AC_DEFINE(HAVE_ALLOCA, 1)
+ fi
+ 
+ AC_CACHE_CHECK([for alloca], ac_cv_func_alloca_works,
+ [AC_TRY_LINK([
+ #ifdef __GNUC__
+ # define alloca __builtin_alloca
+ #else
+ # if HAVE_ALLOCA_H
+ #  include <alloca.h>
+ # else
+ #  ifdef _AIX
+  #pragma alloca
+ #  else
+ #   ifndef alloca /* predefined by HP cc +Olibcalls */
+ char *alloca ();
+ #   endif
+ #  endif
+ # endif
+ #endif
+ ], [char *p = (char *) alloca(1);],
+   ac_cv_func_alloca_works=yes, ac_cv_func_alloca_works=no)])
+ if test "$ac_cv_func_alloca_works" = "yes"; then
+   AC_DEFINE([HAVE_ALLOCA], [1], [If we have a working alloca() implementation])
+ fi
+ 
+ if test "$ac_cv_func_alloca_works" = "no"; then
+   # The SVR3 libPW and SVR4 libucb both contain incompatible functions
+   # that cause trouble.  Some versions do not even contain alloca or
+   # contain a buggy version.  If you still want to use their alloca,
+   # use ar to extract alloca.o from them instead of compiling alloca.c.
+   ALLOCA=alloca.o
+   AC_DEFINE(C_ALLOCA, 1)
+ 
+ AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray,
+ [AC_EGREP_CPP(webecray,
+ [#if defined(CRAY) && ! defined(CRAY2)
+ webecray
+ #else
+ wenotbecray
+ #endif
+ ], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
+ if test "$ac_cv_os_cray" = "yes"; then
+ for ac_func in _getb67 GETB67 getb67; do
+   AC_CHECK_FUNC($ac_func, [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func)
+   break])
+ done
+ fi
+ fi
+ AC_SUBST(ALLOCA)dnl
+else
+ AC_MSG_RESULT("Skipped alloca tests")
+fi
+])