Initial draft.

Author: Lichtso

proposals/0319-remove-executable-flag-entirely.md

@@ -0,0 +1,80 @@
+---
+simd: '0319'
+title: Remove Accounts `is_executable` Flag Entirely
+authors:
+  - Alexander Meißner
+category: Standard
+type: Core
+status: Review
+created: 2025-03-18
+feature: TBD
+extends: 0162
+---
+
+## Summary
+
+Remove the accounts `is_executable` flag from the protocol entirely.
+
+## Motivation
+
+See SIMD-0162 for the reasons why the `is_executable` flag is unnecessary
+protocol complexity. That SIMD however only removes all checks of the flag
+which can abort a transaction. There are other influences the flag has on
+consensus which shall be removed as well.
+
+## New Terminology
+
+None.
+
+## Detailed Design
+
+The following changes in consensus relevant behavior must occur with the
+activation of the feature TBD:
+
+### Account append vector in snapshot format
+
+When loading existing snapshots the flag must be ignored. When storing
+snapshots the flag should be treated as being always `false`.
+
+### Snapshot minimization special case
+
+Program data accounts (owned by loader-v3) must not be filtered by their
+`is_executable` flag anymore.
+
+### Account hash
+
+The flag must not be added to the input of the hash function anymore.
+Note that this is different from hashing it as always `false`.
+
+### VM serialization
+
+ABI v2 will simply not have the flag from the start, however ABI v0 and v1 must
+change their serialization of the flag to be `true` if (and only if):
+
+- an account is owned by loader-v1 or loader-v2
+- an account is owned by loader-v3 and contains the program (proxy) state
+- an account is owned by loader-v4 and has the deployed or finalized status
+
+### CPI special case
+
+Currently CPI ignores changes made by the caller to instruction accounts which
+have the flag set, meaning even requesting write access to a program account
+throws no error. Instead the flag must now be ignored, meaning all changes made
+by the caller to instruction accounts are treated equally.
+
+## Alternatives Considered
+
+None.
+
+## Impact
+
+The changes to the snapshots and account hashes should be irrelevant. The
+changes to the VM serialization should be mostly identical to the existing
+behavior. The changes to the CPI special case will technically allow for a new
+failure mode, when a caller attempts to give write access to a program
+account to a callee, but this case does not seem to occur in currently deployed
+dApps.
+
+## Security Considerations
+
+None.