[clang] 7521ce9 - [clang][bytecode] Don't get the expr without emitting a diagnostic (#141953)

[via cfe-commits]

Author: Timm Baeder
Date: 2025-05-29T17:18:42+02:00
New Revision: 7521ce9963733491229f612208cd44ab5b0337c8

URL: https://github.com/llvm/llvm-project/commit/7521ce9963733491229f612208cd44ab5b0337c8
DIFF: https://github.com/llvm/llvm-project/commit/7521ce9963733491229f612208cd44ab5b0337c8.diff

LOG: [clang][bytecode] Don't get the expr without emitting a diagnostic (#141953)

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Interp.h

Removed: 
    


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diff  --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h
index 5473733578d7e..33de09a263b3e 100644
--- a/clang/lib/AST/ByteCode/Interp.h
+++ b/clang/lib/AST/ByteCode/Interp.h
@@ -200,15 +200,16 @@ bool CheckShift(InterpState &S, CodePtr OpPC, const LT &LHS, const RT &RHS,
 
   if constexpr (Dir == ShiftDir::Left) {
     if (LHS.isSigned() && !S.getLangOpts().CPlusPlus20) {
-      const Expr *E = S.Current->getExpr(OpPC);
       // C++11 [expr.shift]p2: A signed left shift must have a non-negative
       // operand, and must not overflow the corresponding unsigned type.
       if (LHS.isNegative()) {
+        const Expr *E = S.Current->getExpr(OpPC);
         S.CCEDiag(E, diag::note_constexpr_lshift_of_negative) << LHS.toAPSInt();
         if (!S.noteUndefinedBehavior())
           return false;
       } else if (LHS.toUnsigned().countLeadingZeros() <
                  static_cast<unsigned>(RHS)) {
+        const Expr *E = S.Current->getExpr(OpPC);
         S.CCEDiag(E, diag::note_constexpr_lshift_discards);
         if (!S.noteUndefinedBehavior())
           return false;