Description
The purpose of this issue is to explore if it is possible to remove SpEL implementation from the reachable code path by performing an AOT processing of SpEL expressions to generate related bytecode at build-time, and introduce a dedicated BeanExpressionResolver used in AOT mode without a dependency on StandardBeanExpressionResolver with 3 goals:
- Reduce the number of hints required at runtime on native due to SpEL reflection usage
- Avoid loading most of the SpEL infrastructure by default for optimization purpose
- Perform SpEL to bytecode generation at build-time to skip that processing at runtime
Pre-processing of SpEL expressions in annotations like Spring Framework @Value or Spring Security @PreAuthorize / @PostAuthorize / @PreFilter / @PostFilter (cc @rwinch) would be the main use cases, but other potential use cases of BeanExpressionResolver should be explored to ensure the feasibility of this optimization.
Usage of SpEL in Thymeleaf would be probably out of the scope, or would require build-time compilation of Thymeleaf templates which is out of the scope of this issue, even if that's an interesting idea.