test/core: add labs(3) implementation for TIS analyzer

While the ACSL specification for the function prototype is present,
the actual implementation is missing. Not sure why?

1 files changed, 5 insertions, 0 deletions

diff --git a/core/tap.h b/core/tap.h
index 390eb6f..b8a7213 100644
--- a/core/tap.h
+++ b/core/tap.h
@@ -45,6 +45,11 @@ time_t time(time_t *p)
 	return value;
 }
 
+long labs(long v)
+{
+	return v > 0 ? v : -v;
+}
+
 #else
 #include <ccan/tap/tap.h>
 #define TIS_INTERPRETER 0