Clean up deprecated serialization API across F Prime codebase

[devin-ai-integration]

Related Issue(s)	Cleanup of deprecated serialization API surface
Has Unit Tests (y/n)	n (existing tests updated, no new tests)
Documentation Included (y/n)	n
Generative AI was used in this contribution (y/n)	y

---

Change Description

Removes all deprecated serialization API shims from the F Prime framework, completing the migration to the new method names. This was done in 5 phases:

Phase 1 – SerializeBufferBase → LinearBufferBase (~95 files)

• Global rename of the type alias SerializeBufferBase to the canonical name LinearBufferBase in all .hpp and .cpp files (class inheritance, parameter types, comments).
• Renamed test class SerializeBufferBaseTester → LinearBufferBaseTester.
• Removed the using SerializeBufferBase = LinearBufferBase; alias from Fw/Types/Serializable.hpp.

Phase 2 – Deprecated accessor removal

• Removed getBuffCapacity(), getBuffLength(), getBuffLeft() deprecated shim declarations and implementations from all buffer subclasses (DataBuffer, CmdArgBuffer, ComBuffer, LogBuffer, PrmBuffer, TlmBuffer, SmSignalBuffer, StatementArgBuffer, SerialBuffer, HashBuffer, FileBuffer) and from LinearBufferBase/ExternalSerializeBuffer in Serializable.hpp/.cpp.

Phase 3 – Deprecated serialize()/deserialize() shim removal

• Removed ~60 deprecated serialize()/deserialize() wrapper methods from LinearBufferBase (declarations in Serializable.hpp, implementations in Serializable.cpp).
• Removed deprecated serialize()/deserialize() inline methods from Serializable base class.
• Removed deprecated serialize() inline methods from ConstStringBase.
• No callers needed migration — all existing .serialize()/.deserialize() calls in the codebase are on CircularBuffer objects (which have their own non-deprecated API).

Phase 4 – getSerializeRepr() removal

• Removed the deprecated getSerializeRepr() declaration from Fw::Buffer. No callers existed.

Phase 5 – Fw/Deprecate.hpp include removal

• Removed #include "Fw/Deprecate.hpp" from Serializable.hpp since no DEPRECATED macros remain. The Fw/Deprecate.hpp file itself is preserved for downstream use.

Rationale

The deprecated API surface created maintenance burden and confusion. All callers had already been migrated to the new names (serializeFrom/deserializeTo, getCapacity/getSize/getDeserializeSizeLeft, getSerializer/getDeserializer), making the shims dead code ready for removal.

Testing/Review Recommendations

⚠️ Build and test verification was not completed locally. Reviewers should verify CI passes. Key areas to scrutinize:

1. File rename: SerializeBufferBaseTester.hpp → LinearBufferBaseTester.hpp — verify CMakeLists/build references are updated.
2. Type alias removal: Confirm no code outside this diff still references SerializeBufferBase. Generated/autocoded files may need regeneration.
3. Fw/Deprecate.hpp include removal from Serializable.hpp: Any file that transitively relied on this include for its own DEPRECATED macros will now fail to compile. Verify no such files exist.
4. CircularBuffer distinction (Phase 3): CircularBuffer::serialize() is intentionally not touched — it is a separate, non-deprecated API. Verify no LinearBufferBase-derived .serialize() calls were missed.
5. m_serialize_repr member in Fw::Buffer: The deprecated getSerializeRepr() accessor was removed, but the underlying m_serialize_repr member is still used internally by Buffer.cpp constructors and setters — this is intentional and correct.

Future Work

• Downstream/external projects using SerializeBufferBase, getBuffCapacity(), or the deprecated serialize()/deserialize() shims will need to update their code.
• Consider removing the m_serialize_repr member from Fw::Buffer if it is no longer needed after getSerializeRepr() removal (it is currently still used internally).

AI Usage (see policy)

AI (Devin by Cognition) was used for the entire implementation: planning the phased approach, performing the global find-and-replace operations, analyzing call sites to distinguish CircularBuffer vs LinearBufferBase usage, removing deprecated declarations/implementations, and drafting this PR description.

Link to Devin session: https://nasa-jpl-demo.devinenterprise.com/sessions/f4fa8fb484cd4e59ad68cb2a7b6d4c78
Requested by: @jakexcosme

---

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring