[clang] [clang][ExprConst] Remove bogus diagnostic (PR #181792)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/181792

This diagnostic is untested and this code path should be dead.

>From 1f2791337d0e9a9644425ead20854781cfeafb79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Tue, 17 Feb 2026 10:35:44 +0100
Subject: [PATCH] [clang][ExprConst] Remove bogus diagnostic

This diagnostic is untested and this code path should be dead.
---
 clang/include/clang/Basic/DiagnosticASTKinds.td | 6 ------
 clang/lib/AST/ExprConstant.cpp                  | 6 ------
 2 files changed, 12 deletions(-)

diff --git a/clang/include/clang/Basic/DiagnosticASTKinds.td b/clang/include/clang/Basic/DiagnosticASTKinds.td
index f36c02851a6a1..bb3951157e70d 100644
--- a/clang/include/clang/Basic/DiagnosticASTKinds.td
+++ b/clang/include/clang/Basic/DiagnosticASTKinds.td
@@ -429,12 +429,6 @@ def note_constexpr_unscoped_enum_out_of_range : Note<
   "integer value %0 is outside the valid range of values [%1, %2] for the "
   "enumeration type %3">;
 
-// This is a temporary diagnostic, and shall be removed once our
-// implementation is complete, and like the preceding constexpr notes belongs
-// in Sema.
-def note_unimplemented_constexpr_lambda_feature_ast : Note<
-    "unimplemented constexpr lambda feature: %0 (coming soon!)">;
-
 def warn_is_constant_evaluated_always_true_constexpr : Warning<
   "'%0' will always evaluate to 'true' in a manifestly constant-evaluated expression">,
   InGroup<DiagGroup<"constant-evaluated">>;
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 2c13befec02f2..26d4f5afb7603 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -3373,12 +3373,6 @@ static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
              "missing value for local variable");
       if (Info.checkingPotentialConstantExpression())
         return false;
-      // FIXME: This diagnostic is bogus; we do support captures. Is this code
-      // still reachable at all?
-      Info.FFDiag(E->getBeginLoc(),
-                  diag::note_unimplemented_constexpr_lambda_feature_ast)
-          << "captures not currently allowed";
-      return false;
     }
   }