CRAM: C++ to Rust Assisted Migration
Near-automatic migration of C++ source into idiomatic, human-maintainable Rust code.
CRAM (C++ to Rust Assisted Migration) transforms legacy C++ code into safe, modern Rust, quickly, accurately, and at scale. Built on advanced program analysis and refactoring technology, CRAM enables organizations to modernize codebases without the cost and risk of manual rewrites.
Why CRAM?
C++ is not memory safe. Software bugs cost the economy billions of dollars annually. A large fraction are memory errors, which are among the most difficult to repair. Memory safe roadmaps are being recognized as a best practice [CISA].
Today, adopting a new language requires either manual code translation or full-scale reimplementation of legacy code bases.
These approaches are slow, costly, and error-prone, especially if the target language is unfamiliar.
The CRAM Solution
CRAM semi-automatically migrates well-structured, general-purpose C++ into idiomatic Rust, code that is not only correct, but maintainable by human developers.
Rust is a modern, efficient, and safe language, wiping out many memory-related programming errors.
Our approach is unique:
1. C++ Modernization
CRAM starts by refactoring your existing C++ into a safer, modern, more structured version that aligns with Rust-like abstractions and complies with modern C++ coding standards.
2. Language Migration
CRAM identifies patterns and converts them into Rust using proven templates. GrammaTech’s solution is fully deterministic and does not rely on AI or large language models. Given the same input, it will always produce the same output.
3. Human-Readable Output
The resulting Rust code is efficient, provably safe, idiomatic, human-maintainable and modern.
What CRAM Delivers What
Safe, Modern Code
- Generates memory-safe Rust by design
- Eliminates entire classes of memory-related bugs
Faster Migration
- Automatically migrates the bulk of a C++ codebase into Rust in minutes
- Achieves 80%+ translation coverage for well-structured C++ codebases
- Orders of magnitude faster than manual approaches
Reduced Engineering Burden
- Frees developers from tedious translation work
- Minimizes need for full reimplementation
Deterministic and Predictable Results
- Produces consistent, repeatable outputs for the same input
- Eliminates variability introduced by AI or probabilistic systems
- Enables reliable validation, testing, and certification
Immediate Value from Day One
- Produces hardened, improved C++ as a by-product
- Enables reliable validation, testing, and certification
Migration to Memory Safe in Practice
Developed with support from DARPA, CRAM combines advanced automation with expert oversight to deliver:
- Large-scale, production-ready migrations
- Secure, maintainable codebases
- Measurable improvements in performance and reliability
Delivery Model
As a Service Offering
GrammaTech provides CRAM as a fully supported service:
- Code analysis and reverse engineering
- Security evaluation and insights
- Automated transformation and delivery of hardened code
Customization & Support
Our team can also:
- Extend CRAM to handle specialized or legacy patterns (e.g., low-level C-style code)
- Support proprietary or non-standard toolchains
- Deliver C++ refactoring only, without Rust migration
Build the Future on Safe Code
CRAM enables organizations to transition from legacy risk to modern resilience, without starting from scratch.
- Modernize faster
- Reduce risk
- Empower your engineering teams
1CISA, “Case: Memory-Safe Roadmaps,” Cybersecurity & Infrastructure Security Agency (CISA), accessed October 2, 2025, https://www.cisa.gov/resourcestools/ resources/case-memory-safe-roadmaps.
This material is based upon work supported by the Defense Advanced Research Projects Agency (DARPA) under Contract No.HR0011-23-C-0079. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Defense Advanced Research Projects Agency (DARPA).
