Errors building with Clang 3.8: "ignoring return value of function"

Development Platform & Builds
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1

I’m getting errors like this that prevent building with Clang 3.8 on Arch Linux:

UnrealEngine/Engine/Source/Runtime/Core/Private/Linux/LinuxPlatformMisc.cpp:103:3: error: ignoring return value of function declared with warn_unused_result attribute [-Werror,-Wunused-result]
    fscanf(SysFsFile, "%d", &SystemLineSize);

Here’s my build log.

Clang is asking to check the result of these functions instead of ignoring it. I was thinking of submitting a PR, but I’m not sure how to handle the case when they don’t return “1”. It seems that would indicate a serious problem, so should the editor just exit at that point?

As a quick fix, is there somewhere I can add “-Wno-unused-result” as a build flag?

Thanks!

2

You can add that to LinuxToolchain.cs, GetCLArguments_Global() function.

3

Thanks, that worked. Here’s my patch for reference.