[Bug c++/126754] [16/17 Regression] ICE in tsubst_expr, at cp/pt.cc:23354 since r16-5970

"cvs-commit at gcc dot gnu.org via Gcc-bugs" <[email protected]> Fri, 14 Aug 2026 13:37:47 +0000

Newsgroups	gmane.comp.gcc.bugs
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126754

--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-16 branch has been updated by Jason Merrill
<[email protected]>:

https://gcc.gnu.org/g:1ef50505862d6702e95e76b3ce2c5ed3a93610cb

commit r16-9536-g1ef50505862d6702e95e76b3ce2c5ed3a93610cb
Author: Jason Merrill <[email protected]>
Date:   Fri Aug 14 09:37:39 2026 -0400

    c++: constexpr class access in generic lambda [PR126754]

    We don't want to see TARGET_EXPR in template trees because it's an
    implementation detail, not a representation of the source.  But constant
    evaluation normally represents a constant class value with a TARGET_EXPR.
    For GCC 16 let's duplicate the default case handling.

            PR c++/126754

    gcc/cp/ChangeLog:

            * pt.cc (tsubst_expr) <case TARGET_EXPR>: Only unreachable
            when checking.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp1y/constexpr-lambda2.C: New test.