https://github.com/naveen-seth created https://github.com/llvm/llvm-project/pull/166762
Fixes #166328. Fixes a crash that occurs when constevaluating a function in a switch case with a missing non-type template parameter. This change guards against calling `EvaluateKnownConstInt` on value-dependent expressions in switch cases to prevent the crash. >From d151070bae2c2ecd05117686e20b2f75c26f4f2e Mon Sep 17 00:00:00 2001 From: naveen-seth <[email protected]> Date: Thu, 6 Nov 2025 12:59:51 +0100 Subject: [PATCH] [clang][AST] Fix crash in constevaluated switch case statements Fixes #166328. Fixes a crash that occurs when constevaluating a function in a switch case with a missing non-type template parameter. This change guards against calling EvaluateKnownConstInt on value-dependent expressions in switch cases. --- clang/lib/AST/ExprConstant.cpp | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index 8fab6efafb983..5320031f585e7 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -5452,10 +5452,15 @@ static EvalStmtResult EvaluateSwitch(StmtResult &Result, EvalInfo &Info, } const CaseStmt *CS = cast<CaseStmt>(SC); - APSInt LHS = CS->getLHS()->EvaluateKnownConstInt(Info.Ctx); - APSInt RHS = CS->getRHS() ? CS->getRHS()->EvaluateKnownConstInt(Info.Ctx) - : LHS; - if (LHS <= Value && Value <= RHS) { + const Expr *LHSExpr = CS->getLHS(); + const Expr *RHSExpr = CS->getLHS(); + if (LHSExpr->isValueDependent() || (RHSExpr && RHSExpr->isValueDependent())) + return ESR_Failed; + + APSInt LHSValue = LHSExpr->EvaluateKnownConstInt(Info.Ctx); + APSInt RHSValue = + RHSExpr ? RHSExpr->EvaluateKnownConstInt(Info.Ctx) : LHSValue; + if (LHSValue <= Value && Value <= RHSValue) { Found = SC; break; } _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
