How to reduce compile times?

For example, I could imagine that heavy use of templates and CTFE slows the compiler down. Maybe string mixins with CTFE on the module level are most expensive: here, the compiler has to do heavy weight semantic analysis every time a module is imported from another module (maybe even recursively). But I don't really know; it depends too much on how the compiler works internally.

Without some kind of "build profiler", I have no clue what is actually causing slow downs. It's like groping in the dark!

The only thing that comes near to this seems to be to insert a "pragma(msg, blabla)" at random points in your modules. Then you recompile the project and count how many times the message is outputted.

Actually, the whole issue seems to boil down to reducing module dependencies. But then again, your "main" module recursively depends from _all_ used modules in your project.

What I personally found useful in practice is to reduce the number of interdependent modules by separating them into interface and implementation modules, e.g. by using delegates or inheritance. Then you can "hide" the implementation from most modules by removing the static dependencies. But this only works in some cases, and is always inconvenient.

PS: another thing that possibly would bring a speed gain would be to make dsss compile the whole project in one run, instead of invoking a new dmd process for each source file. How do I need to change the rebuild configuration to achieve this?

grauzone wrote: > PS: another thing that possibly would bring a speed gain would be to make dsss compile the whole project in one run, instead of invoking a new dmd process for each source file. How do I need to change the rebuild configuration to achieve this? oneatatime = [yes|no] You want 'no'. This will occasionally produce issues with ModuleInfo not being defined with some dmd versions, I think. Or something like that.

Christopher Wright wrote: > grauzone wrote: >> PS: another thing that possibly would bring a speed gain would be to make dsss compile the whole project in one run, instead of invoking a new dmd process for each source file. How do I need to change the rebuild configuration to achieve this? > > oneatatime = [yes|no] > > You want 'no'. This will occasionally produce issues with ModuleInfo not being defined with some dmd versions, I think. Or something like that. Yes, this causes random linker errors. What I need is to make dsss completely recompile the project, even if only a single source file was modified. This way, no errors should occur, and it would still be faster than with oneatatime=yes. (Damn that crappy support for incremental compilation.)

On Sat, Mar 21, 2009 at 2:50 PM, grauzone <none@example.net> wrote: > What I need is to make dsss completely recompile the project, even if only a single source file was modified. This way, no errors should occur, and it would still be faster than with oneatatime=yes. -full

On 21.03.2009 19:50, grauzone wrote: > Christopher Wright wrote: >> grauzone wrote: >>> PS: another thing that possibly would bring a speed gain would be to >>> make dsss compile the whole project in one run, instead of invoking a >>> new dmd process for each source file. How do I need to change the >>> rebuild configuration to achieve this? >> >> oneatatime = [yes|no] >> >> You want 'no'. This will occasionally produce issues with ModuleInfo not >> being defined with some dmd versions, I think. Or something like that. > > Yes, this causes random linker errors. > Those errors shouldn't happen if you compile one file at a time, I believe. On the other hand, dsss' incremental compilation feature never seems to work for me. > What I need is to make dsss completely recompile the project, even if > only a single source file was modified. This way, no errors should > occur, and it would still be faster than with oneatatime=yes. > > (Damn that crappy support for incremental compilation.) I use bud, which builds everything with a single run of dmd, but uses incremental compilation. If I get linker errors, I just run my cleanup script and try again. Or add -full to bud's command line.

Jarrett Billingsley wrote: > On Sat, Mar 21, 2009 at 2:50 PM, grauzone <none@example.net> wrote: > >> What I need is to make dsss completely recompile the project, even if only a >> single source file was modified. This way, no errors should occur, and it >> would still be faster than with oneatatime=yes. > > -full Sorry for being so helpless, but where do I add this to the rebuild configfile? Also, I noticed that "dsss build -full" seems to be the way to pass this flag on the command line. But the project is recompiled even when no file was modified at all. This is not good: it should only recompile if something has changed.

> I use bud, which builds everything with a single run of dmd, but uses incremental compilation. If I get linker errors, I just run my cleanup script and try again. Or add -full to bud's command line. In my case, this practically always causes linker errors. Of course I don't know why.

On Sat, 21 Mar 2009 15:44:41 +0100, grauzone wrote: > I'm using dsss (with dmd under Linux) to compile my project, and build/compile times are reaching unacceptable highs. out of curiosity, how much code do you actually have? im using D for something with ~12,000 lines of code right now, spread among 40 files or so, with a somewhat excessive use of CTFE and templates all over. a full rebuild takes about 5 seconds with incremental builds taking 1 or 2 seconds in most cases. i just wanted to know what "excessively high" means P.S. using dmd 1.036, rebuild 0.78, phobos, linux

Brian wrote: > On Sat, 21 Mar 2009 15:44:41 +0100, grauzone wrote: > >> I'm using dsss (with dmd under Linux) to compile my project, and >> build/compile times are reaching unacceptable highs. > > out of curiosity, how much code do you actually have? im using D for something with ~12,000 lines of code right now, spread among 40 files or so, with a somewhat excessive use of CTFE and templates all over. a full rebuild takes about 5 seconds with incremental builds taking 1 or 2 seconds in most cases. > > i just wanted to know what "excessively high" means > > P.S. using dmd 1.036, rebuild 0.78, phobos, linux 65906 physical lines of code (+ some Tango .di imports + some small external libraries), maybe 200+ files, takes 1m10s to build when using normal dsss. With -full and oneatatime=no, compile time goes down to 6-7 seconds. It's not that template- and CTFE-heavy. Incremental builds can take relatively long (depending where the changed files are in the dependency tree), and it's really annoying.

grauzone wrote: > Jarrett Billingsley wrote: >> On Sat, Mar 21, 2009 at 2:50 PM, grauzone <none@example.net> wrote: >> >>> What I need is to make dsss completely recompile the project, even if only a >>> single source file was modified. This way, no errors should occur, and it >>> would still be faster than with oneatatime=yes. >> >> -full > > Sorry for being so helpless, but where do I add this to the rebuild configfile? > > Also, I noticed that "dsss build -full" seems to be the way to pass this flag on the command line. But the project is recompiled even when no file was modified at all. This is not good: it should only recompile if something has changed. http://svn.dsource.org/projects/arclib/trunk/arclib/arc/dsss.conf buildflags = -full

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