Improve support for in-memory compilation, helps wasm use #1796

rsheeter · 2025-12-03T22:51:43Z

This PR aspires toward #1791's goal of making in-memory compiles for wasm happier by making it clearer how to say don't touch the disk

Split cli args and compile args so the latter can be more interestingly typed
- cli args just turn --flag --here into a compile arg
Make all paths distinct and optional
- Emit x is removed from Flags
- build_dir is removed, each distinct file we write gets an Option for a path
- It falls out of ^ that to write no files you set all output paths to None

…ore strongly typed

simoncozens · 2025-12-04T07:37:55Z

In #1684 I made it possible to pass a Source in; (useful if you are generating your own IR, not just one of the defined Inputs) this removes that ability, unfortunately.

fontc/src/args.rs

fontc/src/lib.rs

fontbe/src/orchestration.rs

fontc/src/compile_args.rs

fontc/src/lib.rs

fontbe/src/orchestration.rs

fontbe/src/features.rs

anthrotype · 2025-12-04T13:13:48Z

I propose we separate input source from the compilation options and restore the ability to generate_font from Box<dyn Source> for library users. That is:

Before (Rod's PR):

  pub fn generate_font(args: Args) -> Result<Vec<u8>, Error>
  pub fn run(args: Args, timer: JobTimer) -> Result<(), Error>
  // where Args contains input: Input

After:

  pub fn generate_font(source: Box<dyn Source>, options: Options) -> Result<Vec<u8>, Error>  // public library entry point
  pub fn run(input: Input, options: Options, timer: JobTimer) -> Result<(), Error>  // CLI entry point

I'll make a PR now

…rce> support Refactor the compile arguments API to: - Rename `fontc::Args` to `fontc::Options` for clarity (avoids confusion with CLI `args::Args`) - Remove `input` field from Options - source is now passed separately - Update `generate_font()` to accept `Box<dyn Source>` + `Options` - Update `run()` to accept `Input` + `Options` This restores the ability to pass custom `Box<dyn Source>` implementations that was added in #1684, which library users need for generating their own IR programmatically. Also: - Add `Default` derive to `Options` for ergonomic in-memory/WASM usage - Rename `cli_args.rs` back to `args.rs` and delete `compile_args.rs` (Options inlined in lib.rs since it's short enough)

anthrotype · 2025-12-04T14:08:58Z

I'll make a PR now

see #1797 (which is based on this PR branch, not main)

Change require_dir() to use fs::create_dir_all() instead of fs::create_dir() so that nested paths like /tmp/deep/nested/build are created correctly.

…used When both --emit-ir and --output-file are used, the font is first written to {ir_dir}/font.ttf by the persistence mechanism. If output_file differs, we move (rename) the font to the custom output path rather than leaving it in the IR directory. We rename (instead of fs::write or fs::copy) as this matches the current behavior on `main` whereby the font ends up at output_file only and is not duplicated in the IR directory.

cmyr

I've been holding off on merging #1775 because I wanted to discuss some of our options in a bit more depth, but I think it also provides an opportunity to simplify some of this logic.

fontir/src/orchestration.rs

rsheeter · 2025-12-04T16:48:50Z

In #1684 I made it possible to pass a Source in; (useful if you are generating your own IR, not just one of the defined Inputs) this removes that ability, unfortunately.

Oh good catch, will fix.

anthrotype · 2025-12-04T16:49:24Z

Oh good catch, will fix.

I fixed it in #1797, please take a look at that before duplicating work, thanks!

Remove input from fontc::Args, rename as Options; restore `Box<dyn Source>` support

rsheeter · 2025-12-04T17:11:45Z

please take a look at that before duplicating work, thanks!

I feel seen :D

Make cli args and compile args different types so the latter can be m…

81e0e80

…ore strongly typed

rsheeter changed the title ~~[WIP] Compile without paths~~ To support wasm, improve uspport for in-memory compilation Dec 4, 2025

rsheeter marked this pull request as ready for review December 4, 2025 01:00

rsheeter changed the title ~~To support wasm, improve uspport for in-memory compilation~~ Improve support for in-memory compilation, helps wasm use Dec 4, 2025

rsheeter force-pushed the no_path branch from 20973ea to 719f0c7 Compare December 4, 2025 01:04

Make output files and dirs distinct and optional

69a64ec

rsheeter force-pushed the no_path branch from 719f0c7 to 69a64ec Compare December 4, 2025 01:13

rsheeter mentioned this pull request Dec 4, 2025

Make all paths optional #1791

Closed