Fall back to calloc when __builtin_mul_overflow isn't available

[bup.git] / config / configure

diff --git a/config/configure b/config/configure
index 33e9ba26a00da52d3c769e536635483d7f3a7b17..fbf174fd8c95df5e0c591c917699af805102f445 100755 (executable)
--- a/config/configure
+++ b/config/configure
@@ -97,6 +97,25 @@ AC_CHECK_FUNCS utimes
 AC_CHECK_FUNCS lutimes
 
 
+builtin_mul_overflow_code="
+#include <stddef.h>
+int main(int argc, char **argv)
+{
+    size_t n = 0, size = 0, total;
+    __builtin_mul_overflow(n, size, &total);
+    return 0;
+}
+"
+
+TLOGN "checking for __builtin_mul_overflow"
+if bup_try_c_code "$builtin_mul_overflow_code"; then
+    AC_DEFINE BUP_HAVE_BUILTIN_MUL_OVERFLOW 1
+    TLOG ' (found)'
+else
+    TLOG ' (not found)'
+fi
+
+
 AC_CHECK_FUNCS mincore
 
 mincore_incore_code="