[Lldb-commits] [lldb] Summarize std::string's when created from data. (PR #89110)

[Jacob Lalonde via lldb-commits]

================
@@ -254,13 +254,17 @@ bool lldb_private::formatters::LibStdcppStringSummaryProvider(
   } else
     addr_of_string =
         valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
-  if (addr_of_string != LLDB_INVALID_ADDRESS) {
+
+  // We have to check for host address here
+  // because GetAddressOf returns INVALID for all non load addresses.
+  // But we can still format strings in host memory.
+  if (addr_of_string != LLDB_INVALID_ADDRESS ||
+        addr_type == eAddressTypeHost) {
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Jlalond wrote:

We could take the approach you provided. Greg and I originally talked and mentioned how `GetAddressOf` will return the pointer within a buffer in certain cases. I'm not enough of an expert here to have strong opinions but I think we're in a confusing middleground, where GetAddressOf works for Load addresses, but fails for a host address even if we have a pointer internally to a data buffer. 

I think solving that is more fundamental to my (2nd?) PR in lldb, but if we can all agree on the returning invaild for host addresses. I'm okay with that, as long as we also add a comment/documentation to the call that HostAddress addresses are invalid and to instead use a data extractor. My only opinion on that as a new contributor is the API to work with ValueObject's data is clunky, because I can seemingly only construct a copy via `GetData`.

https://github.com/llvm/llvm-project/pull/89110