Differential D31942

: Don't use __has_builtin().
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Authored by jhb on Sep 13 2021, 6:23 PM.

Details

Reviewers

emaste
manu
imp
• hselasky

Commits

rGe77b37914ad6: <linux/overflow.h>: Don't use __has_builtin().
rG9553c6af881e: <linux/overflow.h>: Don't use __has_builtin().

Summary

GCC only added support for __has_builtin in GCC 10. However, all
supported versions of GCC and clang include these builtins so just use
them unconditionally.

This fixes the build with GCC 9.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Lint Passed

Unit

No Test Coverage

Build Status

Buildable 41496
Build 38385: arc lint + arc unit

Event Timeline

jhb created this revision.Sep 13 2021, 6:23 PM

Herald added subscribers: linuxkpi, imp. · View Herald TranscriptSep 13 2021, 6:23 PM

jhb requested review of this revision.Sep 13 2021, 6:23 PM

Harbormaster completed remote builds in B41496: Diff 95068.Sep 13 2021, 6:23 PM

I was asked to add those checks in D25015 but if all the compiler that we support have those it's good for me (that was my guess at the time but didn't bother to check).

This revision is now accepted and ready to land.Sep 13 2021, 6:32 PM

As an alternative, you could define __has_builtin(x) to 1 and suffer with a less precise error message should x not actually be supported.

• hselasky accepted this revision.Sep 14 2021, 7:46 AM

In D31942#720643, @imp wrote:

As an alternative, you could define __has_builtin(x) to 1 and suffer with a less precise error message should x not actually be supported.

We can't really do that. __has_builtin() gets used for various things and in other places it is always defined to 0 when it doesn't exist. Breaking that pattern in a header would probably cause other breakage in the future.

Closed by commit rG9553c6af881e: <linux/overflow.h>: Don't use __has_builtin(). (authored by jhb). · Explain WhySep 15 2021, 4:06 PM

This revision was automatically updated to reflect the committed changes.

jhb added a commit: rG9553c6af881e: <linux/overflow.h>: Don't use __has_builtin()..

jhb added a commit: rGe77b37914ad6: <linux/overflow.h>: Don't use __has_builtin()..May 10 2022, 11:24 PM