cpp: fix nullptr deref for unknown target predefs

1 files changed, 1 insertions, 1 deletions

diff --git a/src/c_lex.c b/src/c_lex.c
index 8e225b6..d1c0205 100644
--- a/src/c_lex.c
+++ b/src/c_lex.c
@@ -2344,7 +2344,7 @@ putdef1(const char *name)
 static void
 putdefs1(const char *s)
 {
-   for (; *s; s += strlen(s) + 1) putdef1(s);
+   if (s) for (; *s; s += strlen(s) + 1) putdef1(s);
 }
 
 static void