build: handle old compilers without restrict keyword

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 4 insertions, 0 deletions

diff --git a/auto.def b/auto.def
index f88976b..8a21550 100644
--- a/auto.def
+++ b/auto.def
@@ -191,6 +191,10 @@ if {"-Werror" in [get-define CFLAGS] && [cctest -cflags -Wno-error]} {
     cc-with {-cflags -Wno-error}
 }
 
+# Very old compilers might not have restrict
+cc-check-some-feature restrict {
+    cctest -declare {extern void restrict_test(const char * restrict param);}
+}
 cc-check-types "long long"
 cc-check-sizeof int