Hi,

I was wondering, if there is a way to pass a macro with value to the compiled program, i.e., something like -Dfoo="bar". And if that is not possible, if there is a way to enumerate all set versions.

I want my application built with different string imported configurations and I have no idea how to tell compiler which configuration to choose, other than hardcoding it.

Thanks,
Martin

The way I like to do it is to pass a module on the command line that contains the custom config. So in the app:

---
import myapp.config;

// use the variables defined in there like normal
---


Now, to define a config file, you do something like:


myconfiguration.d # note that the file name can be anything!
---
module myapp.config; // but each must use this same module config

enum some_key = "some_value";
// and so on
---

Now, when you compile, you build it with a particular config by passing one of those files to the compile:

dmd myapp.d myconfiguration.d # or whatever single config you want



Then you can define as much as you want in the config module, and have as many of them as you want too.

Dne 7.3.2017 v 22:36 Adam D. Ruppe via Digitalmars-d-learn napsal(a):
> The way I like to do it is to pass a module on the command line that contains the custom config. So in the app:
> 
> ---
> import myapp.config;
> 
> // use the variables defined in there like normal
> ---
> 
> 
> Now, to define a config file, you do something like:
> 
> 
> myconfiguration.d # note that the file name can be anything!
> ---
> module myapp.config; // but each must use this same module config
> 
> enum some_key = "some_value";
> // and so on
> ---
> 
> Now, when you compile, you build it with a particular config by passing one of those files to the compile:
> 
> dmd myapp.d myconfiguration.d # or whatever single config you want
> 
> 
> 
> Then you can define as much as you want in the config module, and have as many of them as you want too.

Yeah, that's definitely an option, but I expect to have troubles with DUB if I use this approach. Also, I need these files to be json, not a D code, because the same configuration mechanism can be used during runtime and I need to parse these files easily.

So far, I incline to have a build script run separate builds and copying different configuration files to one predefined and hardcode its name into a string import, thus sidestepping the problem.

Anyway, thanks for an idea.

Martin

On Wednesday, 8 March 2017 at 12:00:40 UTC, Martin Drašar wrote:
> Yeah, that's definitely an option, but I expect to have troubles with DUB if I use this approach.

ugh dub really show offer some way to pass individual modules too. Maybe we can request a `--passthrough something_to_pass_to_dmd_unmodified` feature.

> Also, I need these files to be json, not a D code, because the same configuration mechanism can be used during runtime and I need to parse these files easily.

You could use the string import feature which is basically the same deal on dmd, just do `-Jpath/to/specific/config/directory`... but again, not sure if dub's command line will let you do that. I know its config file will though, "stringImportPaths".

But it would have to be a directory regardless, can't do individual files from the command line for string imports.


> So far, I incline to have a build script run separate builds and copying different configuration files to one predefined and hardcode its name into a string import, thus sidestepping the problem.

Yeah, that works too.