The previous approach broke code generation for the MS ABI due to an
unintended code path during constraint substitution. This time we
address the issue by inspecting the evaluation contexts and thereby
avoiding that code path.
This reapplies 96eced624 (#102857).
This patch partially implements CWG2369 for non-lambda-constrained
functions.
Lambdas are left intact at this point because we need extra work to
correctly instantiate captures before the function instantiation.
As a premise of CWG2369, this patch also implements CWG2770 to ensure
the function parameters are instantiated on demand.
Closes https://github.com/llvm/llvm-project/issues/54440
Prior to the patch, we didn't build a DeclRefExpr if the Decl being
referred to is invalid, because many clang downstream AST consumers
assume it, violating it will cause many diagnostic regressions.
With this patch, we build a DeclRefExpr enven for an invalid decl (when the
AcceptInvalidDecl is true), and wrap it with a dependent-type
RecoveryExpr (to prevent follow-up semantic analysis, and diagnostic
regressions).
This is a revised version of https://reviews.llvm.org/D76831
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D121599
We would previously try to evaluate atomic constraints of non-template functions as-is,
and since they are now unevaluated at first, this would cause incorrect evaluation (bugs #44657, #44656).
Substitute into atomic constraints of non-template functions as we would atomic constraints
of template functions, in order to rebuild the expressions in a constant-evaluated context.
As per P1980R0, constraint expressions are unevaluated operands, and their constituent atomic
constraints only become constant evaluated during satisfaction checking.
Change the evaluation context during parsing and instantiation of constraints to unevaluated.