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

[Michael Buch via lldb-commits]

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@@ -538,6 +538,40 @@ Interpreter::Visit(const UnaryOpNode &node) {
                                               node.GetLocation());
 }
 
+llvm::Expected<lldb::ValueObjectSP>
+Interpreter::PointerOffset(lldb::ValueObjectSP ptr, lldb::ValueObjectSP offset,
+                           bool positive, uint32_t location) {
+  if (ptr->GetCompilerType().IsPointerToVoid())
+    return llvm::make_error<DILDiagnosticError>(
+        m_expr, "arithmetic on a pointer to void", location);
+  if (ptr->GetValueAsUnsigned(0) == 0 && offset != 0)
+    return llvm::make_error<DILDiagnosticError>(
+        m_expr, "arithmetic on a nullptr is undefined", location);
+
+  bool success;
+  int64_t offset_int = offset->GetValueAsSigned(0, &success);
----------------
Michael137 wrote:

Why can't we just rely on the `offset` `ValueObject` to carry information about its signedness? If we just do `offset->GetValueAsSigned`, why is that always positive at the moment? Do we drop the signedness somewhere ealier, so we have to restore it here?

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