* compiler-specific extensions.
*/
-/*
- * This was introduced by Clang:
- *
- * https://clang.llvm.org/docs/LanguageExtensions.html#has-attribute
- *
- * in some version (which version?); it has been picked up by GCC 5.0.
- */
-#ifndef __has_attribute
- /*
- * It's a macro, so you can check whether it's defined to check
- * whether it's supported.
- *
- * If it's not, define it to always return 0, so that we move on to
- * the fallback checks.
- */
- #define __has_attribute(x) 0
-#endif
-
/*
* NORETURN, before a function declaration, means "this function
* never returns". (It must go before the function declaration, e.g.
|| ND_IS_AT_LEAST_GNUC_VERSION(2,5) \
|| ND_IS_AT_LEAST_SUNC_VERSION(5,9) \
|| ND_IS_AT_LEAST_XL_C_VERSION(10,1) \
- || ND_IS_AT_LEAST_HP_C_VERSION(6,10)
+ || ND_IS_AT_LEAST_HP_C_VERSION(6,10) \
+ || __TINYC__
/*
* Compiler with support for __attribute((noreturn)), or GCC 2.5 and
+ * later, or some compiler asserting compatibility with GCC 2.5 and
* later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
- * and later (do any earlier versions of XL C support this?), or
- * HP aCC A.06.10 and later.
+ * and later (do any earlier versions of XL C support this?), or HP aCC
+ * A.06.10 and later, or current TinyCC.
*/
#define NORETURN __attribute((noreturn))
#define NORETURN_FUNCPTR
#endif
+/*
+ * WARN_UNUSED_RESULT, before a function declaration, means "the caller
+ * should use the result of this function" (even if it's just a success/
+ * failure indication).
+ */
+#if __has_attribute(warn_unused_result) \
+ || ND_IS_AT_LEAST_GNUC_VERSION(3,4) \
+ || ND_IS_AT_LEAST_HP_C_VERSION(6,25)
+ #define WARN_UNUSED_RESULT __attribute((warn_unused_result))
+#else
+ #define WARN_UNUSED_RESULT
+#endif
+
/*
* PRINTFLIKE(x,y), after a function declaration, means "this function
* does printf-style formatting, with the xth argument being the format