My advice on implementing stuff in C: [LWN.net]

My advice on implementing stuff in C:

Posted Oct 18, 2010 8:41 UTC (Mon) by marcH (subscriber, #57642)
In reply to: My advice on implementing stuff in C: by paulj
Parent article: Russell: On C Library Implementation

> Have you looked at Vala? Modern OOP language that builds on GLib and spits out C.

Compiling to a lower-level yet still "human-writable" language is an interesting approach that can be successful to some extend. However it always has this major drawback: debugging & profiling becomes incredibly more difficult. It also gives a really hard time to fancy IDEs. All these need tight integration and the additional layer of indirection breaks that. So handing maintenance of average/poor quality code over to other developers becomes nearly impossible.

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My advice on implementing stuff in C:

Posted Oct 18, 2010 9:09 UTC (Mon) by mjthayer (guest, #39183) [Link] (3 responses)

> Compiling to a lower-level yet still "human-writable" language is an interesting approach that can be successful to some extend. However it always has this major drawback: debugging & profiling becomes incredibly more difficult.

Without having looked at Vala, I don't see why this has to be the case. C itself is implemented as a pipeline, this would just add one stage onto the end. The main problem to solve that I can see is how to pass information down to the lower levels about what C code corresponds to which Vala code.

My advice on implementing stuff in C:

Posted Oct 18, 2010 9:28 UTC (Mon) by cladisch (✭ supporter ✭, #50193) [Link] (2 responses)

> The main problem to solve that I can see is how to pass information down to the lower levels about what C code corresponds to which Vala code.

C has the #line directive for that (GCC doc); AFAIK Vala generates it when in debug mode.

My advice on implementing stuff in C:

Posted Oct 18, 2010 10:58 UTC (Mon) by mjthayer (guest, #39183) [Link]

> C has the #line directive for that (GCC doc); AFAIK Vala generates it when in debug mode.
Sounds reasonable as long as they skip the pre-processor stage, otherwise things might get rather confused. I assume that their variables map one-to-one to C variables to simplify debugging.

My advice on implementing stuff in C:

Posted Oct 19, 2010 11:23 UTC (Tue) by nix (subscriber, #2304) [Link]

I don't entirely understand why they don't generate it always. GCC's own preprocessor does. If you don't, even compiler error messages will be wrong, and you want them to be right even if you're not in debug mode.