codeql/change-notes/1.23/analysis-cpp.md

Improvements to C/C++ analysis

The following changes in version 1.23 affect C/C++ analysis in all applications.

General improvements

New queries

Query	Tags	Purpose
Hard-coded Japanese era start date (cpp/japanese-era/exact-era-date)	reliability, japanese-era	This query is a combination of two old queries that were identical in purpose but separate as an implementation detail. This new query replaces Hard-coded Japanese era start date in call (cpp/japanese-era/constructor-or-method-with-exact-era-date) and Hard-coded Japanese era start date in struct (cpp/japanese-era/struct-with-exact-era-date).

Changes to existing queries

Query	Expected impact	Change
Query name (query id)	Expected impact	Message.
Hard-coded Japanese era start date in call (cpp/japanese-era/constructor-or-method-with-exact-era-date)	Deprecated	This query has been deprecated. Use the new combined query Hard-coded Japanese era start date (cpp/japanese-era/exact-era-date) instead.
Hard-coded Japanese era start date in struct (cpp/japanese-era/struct-with-exact-era-date)	Deprecated	This query has been deprecated. Use the new combined query Hard-coded Japanese era start date (cpp/japanese-era/exact-era-date) instead.
Hard-coded Japanese era start date (cpp/japanese-era/exact-era-date)	More correct results	This query now checks for the beginning date of the Reiwa era (1st May 2019).

Changes to QL libraries

• The data-flow library has been extended with a new feature to aid debugging. Instead of specifying isSink(Node n) { any() } on a configuration to explore the possible flow from a source, it is recommended to use the new Configuration::hasPartialFlow predicate, as this gives a more complete picture of the partial flow paths from a given source. The feature is disabled by default and can be enabled for individual configurations by overriding int explorationLimit().
• There is now a DataFlow::localExprFlow predicate and a TaintTracking::localExprTaint predicate to make it easy to use the most common case of local data flow and taint: from one Expr to another.