add makeSystemError*() helper functions

[folly.git] / folly / CppAttributes.h

diff --git a/folly/CppAttributes.h b/folly/CppAttributes.h
index 7a13f61517cd1220666f6c5b4c5e551e718e03bd..2ebbae8cff35a164d3f778da3db64da12c91ead9 100644 (file)
--- a/folly/CppAttributes.h
+++ b/folly/CppAttributes.h
@@ -53,8 +53,12 @@
  *     FOLLY_FALLTHROUGH; // no warning: annotated fall-through
  * }
  */
-#if FOLLY_HAS_CPP_ATTRIBUTE(clang::fallthrough)
+#if FOLLY_HAS_CPP_ATTRIBUTE(fallthrough)
+#define FOLLY_FALLTHROUGH [[fallthrough]]
+#elif FOLLY_HAS_CPP_ATTRIBUTE(clang::fallthrough)
 #define FOLLY_FALLTHROUGH [[clang::fallthrough]]
+#elif FOLLY_HAS_CPP_ATTRIBUTE(gnu::fallthrough)
+#define FOLLY_FALLTHROUGH [[gnu::fallthrough]]
 #else
 #define FOLLY_FALLTHROUGH
 #endif
@@ -103,3 +107,15 @@
 #define FOLLY_NULLABLE
 #define FOLLY_NONNULL
 #endif
+
+/**
+ * "Cold" indicates to the compiler that a function is only expected to be
+ * called from unlikely code paths. It can affect decisions made by the
+ * optimizer both when processing the function body and when analyzing
+ * call-sites.
+ */
+#if __GNUC__
+#define FOLLY_COLD __attribute__((__cold__))
+#else
+#define FOLLY_COLD
+#endif