codeql/change-notes/1.24/analysis-cpp.md

Improvements to C/C++ analysis

The following changes in version 1.24 affect C/C++ analysis in all applications.

General improvements

New queries

Query	Tags	Purpose

Changes to existing queries

Query	Expected impact	Change
Hard-coded Japanese era start date (cpp/japanese-era/exact-era-date)		This query is no longer run on LGTM.
No space for zero terminator (cpp/no-space-for-terminator)	Fewer false positive results	This query has been modified to be more conservative when identifying which pointers point to null-terminated strings. This approach produces fewer, more accurate results.

Changes to libraries

• The new class StackVariable should be used in place of LocalScopeVariable in most cases. The difference is that StackVariable does not include variables declared with static or thread_local.
  • As a rule of thumb, custom queries about the values of variables should be changed from LocalScopeVariable to StackVariable, while queries about the name or scope of variables should remain unchanged.
  • The LocalScopeVariableReachability library is deprecated in favor of StackVariableReachability. The functionality is the same.