Clang effort

Hello all,

  I'm doing some basic compiler research and am trying to figure out
roughly how much it would cost(time and/or money) to build a
c++(c++98) front-end similar to Clang.

Thanks

That's hard to say. One estimate from ohloh.net says it took 173 person years at $9.5M:
http://www.ohloh.net/p/clang/estimated_cost

-Chris

Chris Lattner <clattner@apple.com> writes:

That's hard to say. One estimate from ohloh.net says it took 173 person
years at $9.5M: http://www.ohloh.net/p/clang/estimated_cost

Here's what sloccount estimates:

Total Physical Source Lines of Code (SLOC) = 397,368
Development Effort Estimate, Person-Years (Person-Months) = 107.20 (1,286.36)
(Basic COCOMO model, Person-Months = 2.4 * (KSLOC**1.05))
Schedule Estimate, Years (Months) = 3.16 (37.98)
(Basic COCOMO model, Months = 2.5 * (person-months**0.38))
Estimated Average Number of Developers (Effort/Schedule) = 33.87
Total Estimated Cost to Develop = $ 14,480,853
(average salary = $56,286/year, overhead = 2.40).

Interesting that this estimates less time but more money than Ohloh. I imagine the Ohloh estimate of time is more accurate, as it is tracking the entire revision control history. Large parts of clang have been refactored or rewritten over the years as it becomes clear what the correct approach is, and it's very optimistic to assume that a new project would be able to avoid this and get to the correct solution (or, at least, one as correct as clang-TOT) on the first attempt.

David