[Lldb-commits] [lldb] [lldb] Add pointer arithmetics for addition and subtraction to DIL (PR #184652)

[Michael Buch via lldb-commits]

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@@ -602,6 +642,62 @@ llvm::Expected<lldb::ValueObjectSP> Interpreter::EvaluateBinarySubtraction(
   if (result_type.IsScalarType())
     return EvaluateScalarOp(BinaryOpKind::Sub, lhs, rhs, result_type, location);
 
+  auto lhs_type = lhs->GetCompilerType();
+  auto rhs_type = rhs->GetCompilerType();
+
+  // "pointer - integer" operation.
+  if (lhs_type.IsPointerType() && rhs_type.IsInteger())
+    return PointerAdd(lhs, -rhs->GetValueAsUnsigned(0), location);
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Michael137 wrote:

Can you explain the `-` and how we rely on unsigned overflow behaviour here?

https://github.com/llvm/llvm-project/pull/184652