[lldb] [llvm] [lldb] Return an llvm::Expected from DWARFExpression::Evaluate (NFCI) (PR #94420)

[David Spickett via llvm-commits]

================
@@ -2244,30 +2108,26 @@ bool DWARFExpression::Evaluate(
         const uint64_t piece_bit_offset = opcodes.GetULEB128(&offset);
         switch (stack.back().GetValueType()) {
         case Value::ValueType::Invalid:
-          return false;
+          return llvm::createStringError(
+              "unable to extract bit value from invalid value.");
         case Value::ValueType::Scalar: {
           if (!stack.back().GetScalar().ExtractBitfield(piece_bit_size,
                                                         piece_bit_offset)) {
-            if (error_ptr)
-              error_ptr->SetErrorStringWithFormat(
-                  "unable to extract %" PRIu64 " bit value with %" PRIu64
-                  " bit offset from a %" PRIu64 " bit scalar value.",
-                  piece_bit_size, piece_bit_offset,
-                  (uint64_t)(stack.back().GetScalar().GetByteSize() * 8));
-            return false;
+            return llvm::createStringError(
+                "unable to extract %" PRIu64 " bit value with %" PRIu64
+                " bit offset from a %" PRIu64 " bit scalar value.",
+                piece_bit_size, piece_bit_offset,
+                (uint64_t)(stack.back().GetScalar().GetByteSize() * 8));
           }
         } break;
 
         case Value::ValueType::FileAddress:
         case Value::ValueType::LoadAddress:
         case Value::ValueType::HostAddress:
-          if (error_ptr) {
-            error_ptr->SetErrorStringWithFormat(
-                "unable to extract DW_OP_bit_piece(bit_size = %" PRIu64
-                ", bit_offset = %" PRIu64 ") from an address value.",
-                piece_bit_size, piece_bit_offset);
-          }
-          return false;
+          return llvm::createStringError(
----------------
DavidSpickett wrote:

Which overload is this calling?

The ones in https://github.com/llvm/llvm-project/blob/775ebc1d710517ddb886ee8aec504e33bed38f52/llvm/include/llvm/Support/Error.h#L1256 that take a format all require an error code.

https://github.com/llvm/llvm-project/pull/94420