From b18c348cae3b57a494be95f7f36f74d921148c07 Mon Sep 17 00:00:00 2001
From: Luna Kim <177369799+luna-y-kim@users.noreply.github.com>
Date: Fri, 22 May 2026 17:56:44 -0700
Subject: [PATCH] build: remove -Wno-unused-result from gcc options

Background: this flag was originally added in commit c5494ac06 (2015-11-24)
with the message "...now builds linux+gcc...". It was later refactored
in commit 62d7164d3 (2017-01-23). From investigation, it seems to be preventative
rather than reactive because it does not actively suppress warnings,
but `-Werror` is enabled under the condition NOT MSVC + STOP_ON_WARNING
(originally in CMakeLists.txt, now in compiler.cmake:126).

Compile tests without `-Wno-unused-result` but with `-Wunused-result`
explicitly enabled were conducted on the following commits,
and all compiled successfully without unused result warnings.
- 312793af4 (2026-01-01)
- 682825f9d (2025-01-01)
- 48362b26c (2024-01-01)
- 3b8807df8 (2023-01-01)
- 62d7164d3 (2017-01-23): refactored
- c5494ac06 (2015-11-24): originally added

Decision: the flag can be safely removed. Removing it allows gcc to catch
unused return values, which is required for the `OIIO_NODISCARD`
and `OIIO_NODISCARD_ERROR` macros to work as intended.

Related: #5196
Assisted-by: Claude / Opus 4.7
Signed-off-by: Luna Kim <177369799+luna-y-kim@users.noreply.github.com>
---
 src/cmake/compiler.cmake | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/cmake/compiler.cmake b/src/cmake/compiler.cmake
index 6936ac51b9..f975b24909 100644
--- a/src/cmake/compiler.cmake
+++ b/src/cmake/compiler.cmake
@@ -185,7 +185,6 @@ endif ()
 if (CMAKE_COMPILER_IS_GNUCC AND NOT (CMAKE_COMPILER_IS_CLANG OR CMAKE_COMPILER_IS_APPLECLANG))
     # gcc specific options
     add_compile_options ("-Wno-unused-local-typedefs")
-    add_compile_options ("-Wno-unused-result")
     add_compile_options ("-Wno-aligned-new")
     add_compile_options ("-Wno-noexcept-type")
 endif ()