API/ABI/CMD Stability in R2

Since r2-6.0.0 the ABI_VERSION define avoid plugins built with different ABI to be loaded to avoid segfaults.

Introduction

Since r2-5.6.0 the development model has changed in order to provide a reliable way to push updates without the need to recompile the plugins, tools and api bindings.

In order to achieve this, the contributions need to follow some new rules in order to be merged, so we ensure that binaries keep stable.

As it's said, odd version numbers are development versions that are only available in git form. The releases are always an even number (0, 2, 4, 6, 8).

When X.Y.9 is reached, it's time to merge all the pull requests tagged for the next big release, the .9 versions are always the most unstable as they focus on quick development in order to make all the breaking changes needed to introduce new features or simplify the usage of some apis.

Development rules

What you CANNOT do between X.Y.0 and X.Y.8:

• Add, Remove or rename public functions, structs or enums
• Change function signature (adding or removing arguments)
• Add, remove or reorder fields in structs
• Remove or change r2 commands (must be documented in release)

What you CAN do between X.Y.0 and X.Y.8:

• Remove global symbols (they shouldn't be accessed directly anyway)
• Change internal structs or functions (static)
• Refactor the programs (those are not libraries and dont expose apis)
• If you really need to add a new public function use R2_XY0 static inline
  • This way the function is inlined and no new symbols are exposed.
• Add new r2 commands
• Add, rename or remove plugins
• Extend r2 commands with new arguments, not breaking previous behaviour)
• Fix memleaks, race conditions, bugs, improve performance, usability, documentation, etc
• Add breaking code under #if R2_XY0 to be removed when .9 arrives
• Use R_DEPRECATE to tag everything that will be removed when .9 is reached

What you MUST do in X.Y.9:

• Remove everything marked as R_DEPRECATE or R2_XY0. Use git grep to find them out
• Anything that was forbidden

CI

All this is checked in the CI with the abidiff utility.

.github/workflows/build.yml#L607