portability and standards: add BSD-like err() and errx() functions

These are BSD functions.
- HaikuOS now compiles without having to use libbsd.
- Tested on SerenityOS (for fun), which doesn't have these functions (yet).
  With a small change to support wcwidth() sfeed works on SerenityOS.

1 files changed, 8 insertions, 0 deletions

diff --git a/util.h b/util.h
index 15d6702..1570d67 100644
--- a/util.h
+++ b/util.h
@@ -38,6 +38,14 @@ enum {
 	FieldLast
 };
 
+/* hint for compilers and static analyzers that a function exits */
+#ifndef __dead
+#define __dead
+#endif
+
+__dead void err(int, const char *, ...);
+__dead void errx(int, const char *, ...);
+
 int uri_format(char *, size_t, struct uri *);
 int uri_hasscheme(const char *);
 int uri_makeabs(struct uri *, struct uri *, struct uri *);