Restore dead code elimination for callbacks by reverting to constant MethodByName lookups

[jquirke]

Summary

• Restores the callBackToMethodValue function removed in commit 725aa5b
• Fixes dead code elimination optimization while preserving data race fixes
• Adds comprehensive documentation warning against future modifications
• Closes issue Commit 725aa5b5f broke dead code elimination #7622

Problem

Commit 725aa5b replaced the specialized function with MethodByName(string(cbName)) to fix data race issues, but inadvertently broke dead code elimination. Using "MethodByName with a variable parameter prevents optimization, potentially increasing binary size" for large projects.

Solution

• Restored callBackToMethodValue function with explicit string constants
• Replaced dynamic calls with callBackToMethodValue(modelValue, cbName)
• Added strong documentation explaining why optimization is critical
• Preserved all data race fixes from the original commit

Impact

• Enables dead code elimination for enterprise customers with large binaries
• Maintains thread safety fixes from the original commit
• No functional API changes

Test Plan

• All existing schema tests pass
• Data race test continues to pass
• Code compiles successfully
• No breaking changes to public API

[propel-code-bot]

Re-introduce callBackToMethodValue to re-enable dead-code elimination in callback detection

Restores a specialized reflection helper that was removed in commit 725aa5b, switching callback resolution back to constant-based MethodByName invocations. This change prevents the Go linker from retaining unused callback methods, recovering binary size optimizations while keeping the earlier data-race fixes. A comprehensive test suite (schema/deadcode_test.go) is added to guard the behaviour and document the optimisation rationale.

Key Changes

• Added callBackToMethodValue, getCRUDCallbackMethod, and getLifecycleCallbackMethod in schema/schema.go with exhaustive switches over callbackType string constants
• Replaced dynamic modelValue.MethodByName(string(cbName)) with callBackToMethodValue(modelValue, cbName) inside the callback detection loop
• Inserted detailed comments explaining compiler/linker behaviour and referencing go#62257
• Added ~130-line test file schema/deadcode_test.go including three focused tests: detection correctness, optimisation preservation, and documentation guard
• Incremented callback detection unit tests to validate true/false flags across models with and without hooks

Affected Areas

• schema/schema.go callback resolution logic
• Unit test coverage in schema/deadcode_test.go

This summary was automatically generated by @propel-code-bot