From: Marek Polacek <polacek@redhat.com>
Date: Thu, 12 Nov 2020 01:18:06 +0000 (-0500)
Subject: system: Add WARN_UNUSED_RESULT
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=876b45db81a708616d70b1ab66b71bd503809c21;p=gcc.git

system: Add WARN_UNUSED_RESULT

I'd like to have the option of marking functions with
__attribute__ ((__warn_unused_result__)), so this patch adds a macro.
And use it for maybe_wrap_with_location, it's always a bug if the
return value is not used, which happened to me and got me confused.

gcc/ChangeLog:

	* system.h (WARN_UNUSED_RESULT): Define for GCC >= 3.4.
	* tree.h (maybe_wrap_with_location): Add WARN_UNUSED_RESULT.
---

diff --git a/gcc/system.h b/gcc/system.h
index b0f3f1dd019..6f6ab616a61 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -789,6 +789,12 @@ extern void fancy_abort (const char *, int, const char *)
 #define ALWAYS_INLINE inline
 #endif
 
+#if GCC_VERSION >= 3004
+#define WARN_UNUSED_RESULT __attribute__ ((__warn_unused_result__))
+#else
+#define WARN_UNUSED_RESULT
+#endif
+
 /* Use gcc_unreachable() to mark unreachable locations (like an
    unreachable default case of a switch.  Do not use gcc_assert(0).  */
 #if (GCC_VERSION >= 4005) && !ENABLE_ASSERT_CHECKING
diff --git a/gcc/tree.h b/gcc/tree.h
index 684be10b440..9a713cdb0c7 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1214,7 +1214,7 @@ get_expr_source_range (tree expr)
 extern void protected_set_expr_location (tree, location_t);
 extern void protected_set_expr_location_if_unset (tree, location_t);
 
-extern tree maybe_wrap_with_location (tree, location_t);
+WARN_UNUSED_RESULT extern tree maybe_wrap_with_location (tree, location_t);
 
 extern int suppress_location_wrappers;