Some Questions to onGenerate

I am playing with onGenerate for my experimental Nim target. Some things are not completely clear for me:

  1. I can’t see any difference if I use --no-output or not. Does it make any change when I use it ?
  2. Can I give a platform_name for that target - or what platform_name is used when no platform is specified ?
  3. In order to build a standard library I want to create a _std directory in the platform directory to put the shadowed modules there. Is this possible from onGenerate/onAfterGenerate. Currently I have the modules in the root path, but this is a bit painful, because I need a lot of #if in order to distinguish between macro and target
  4. Is -D analyzer-optimize applied for onGenerate/onAfterGenerate. I see that the inliner is applied, but sometimes I get a chain of unnecessary assignments. For what I thought is, that it is applied before onAfterGenerate. But maybe I do something wrong to get the final types there.
  5. I am thinking of some optimizations. Can I analyze the code in onGenerate and for example mark a function to be inlined and then get it inlined in onAfterGenerate ?

Cheers, Adrian.


I don’t have all the answers but I hope this can help:

  1. The only difference is there is no output on your file system.
  2. I am not sure, I think I would target js and use Compiler.setCustomJSGenerator. If your Nim target comes as a Haxelib, you can try to add -js output.js to your extraParams.hxml to “hide” the underlying js target. Also maybe it is possible to bypass the js package with Compiler.define if you set js to 0.
  3. I have some doubt just creating an _std directory in the platform directory will make it work, but if it does I would not do it in onGenerate. Maybe you can use Compiler.patchTypes instead.
  4. It is applied before both. Try using -dce full alongside because -D analyzer-optimize does not replace the DCE.
  5. Inlining happens before onGenerate, but you can probably inline and make any additional optimizations yourself before writing Nim files.

Good luck :slight_smile:

Hi Dimitri,
thanks for the directions. I will give them a try. Since Nim is a static target I will try to shadow hl instead of js

is there any documentation about how a patchFile must look for Compiler.patchTypes. I can only guess from looking at the source and found some patch files in use - so I will try…
Cheers, Adrian.