Bug 286324 – ciso646:46:4: warning: "<ciso646> is deprecated in C++17, use <version> to detect implementation-specific macros" [-W#warnings]

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKitGTK

[Michael Catanzaro]

When building with libstdc++, we have a warning spam:

In file included from /builddir/build/BUILD/webkitgtk-2.47.3-build/webkitgtk-2.47.3/Source/WebCore/PAL/pal/text/TextCodecICU.cpp:27:
In file included from /builddir/build/BUILD/webkitgtk-2.47.3-build/webkitgtk-2.47.3/Source/WebCore/PAL/config.h:39:
/usr/bin/../lib/gcc/x86_64-redhat-linux/15/../../../../include/c++/15/ciso646:46:4: warning: "<ciso646> is deprecated in C++17, use <version> to detect implementation-specific macros" [-W#warnings]
   46 | #  warning "<ciso646> is deprecated in C++17, use <version> to detect implementation-specific macros"
      |    ^
1 warning generated.

[Michael Catanzaro]

Found https://en.cppreference.com/w/cpp/header/ciso646 which says:

> Prior to C++20, including <ciso646> was sometimes used as a technique for obtaining definitions of implementation-specific library version macros without causing other effects. As of C++20, the header <version> was added for this purpose.

I think that's what we're using it for, so let's switch to <version> instead. If this fails on PlayStation EWS, then we can try guarding it behind __has_include().

[Michael Catanzaro]

Pull request: https://github.com/WebKit/WebKit/pull/39464

[EWS]

Committed 289666@main (403fba703947): <https://commits.webkit.org/289666@main>

Reviewed commits have been landed. Closing PR #39464 and removing active labels.