0001-Add-pg_nodiscard-function-declaration-specifier.patch

From 32a9bc5cd2c63500670b663964e878e4474ce257 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Sat, 17 Oct 2020 08:38:39 +0200
Subject: [PATCH 1/3] Add pg_nodiscard function declaration specifier

pg_nodiscard means the compiler should warn if the result of a
function call is ignored.  The name "nodiscard" is chosen in alignment
with (possibly future) C and C++ standards.  It maps to the GCC
attribute warn_unused_result.
---
 src/include/c.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/include/c.h b/src/include/c.h
index 9cd67f8f76..d5dc3632f7 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -111,6 +111,18 @@
 #define pg_attribute_unused()
 #endif
 
+/*
+ * pg_nodiscard means the compiler should warn if the result of a function
+ * call is ignored.  The name "nodiscard" is chosen in alignment with
+ * (possibly future) C and C++ standards.  For maximum compatibility, use it
+ * as a function declaration specifier, so it goes before the return type.
+ */
+#ifdef __GNUC__
+#define pg_nodiscard __attribute__((warn_unused_result))
+#else
+#define pg_nodiscard
+#endif
+
 /*
  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
  * used in assert-enabled builds, to avoid compiler warnings about unused
-- 
2.28.0