[ETW] ETW log exporter possible memory ownership issues

[marcalff]

This is not confirmed with testing, only a suspicion raised by code review.

The ostream log exporter has memory ownership issues that can lead to crashes.

See related:

• heap-use-after-free with BatchLogRecordProcessor #3135
• common::MakeAttributes creates garbled output for std::string #2651
• [EXPORTER] ostream log exporter, fix memory ownership issues #3417
• Fix lifetime for sdk::ReadWriteLogRecord #3147

It turns out (seen by code review) that file etw_logger.h uses exactly the same pattern,
so it should be subject to the same issues.

  std::unordered_map<std::string, opentelemetry::common::AttributeValue> attributes_map_;
  opentelemetry::common::AttributeValue body_ = opentelemetry::nostd::string_view();

attributes_map_ and body_ can contain stale pointers.

[lalitb]

Is this issue related to ETW exporter (as in title), or ostream ?

[marcalff]

Is this issue related to ETW exporter (as in title), or ostream ?

This is about ETW, see file etw_logger.h