Add `profile.release` to `Cargo.toml` generated by `cargo component new` #289

calvinrp · 2024-05-06T20:29:59Z

This adds a default [profile.release]:

[profile.release]
codegen-units = 1
opt-level = "s"
debug = false
strip = true
lto = true

The cargo component build --release of the cargo component new --lib output goes from 1.6 MB -> 52 KB.

…`release.profile`

calvinrp · 2024-05-07T18:37:20Z

@fibonacci1729 @macovedj can you merge? I don't have permissions

This commit effectively reverts bytecodealliance#289 and removes the generated `[profile.release]` section from `Cargo.toml` when executing `cargo component new`. The PR mentions that a default release build decreases from 1.6M to 52KB and that was likely due to stripping DWARF debugging information rather than many of the other settings configured. Nowadays for example a default release build (with no extra configuration and no `profile.release`) is around 50KB because rustc/cargo have started stripping debuginfo by default in release mode. That means that the original motivation is still solved, the "default" build is not an alarmingly large 1.6M. Otherwise the various settings configured here can have negative effects which aren't always easy to debug if you're not familiar with them, for example: * `lto = true` and `codegen-units = 1` can massively increase the time needed for a build. This can be surprising to newcomers who may have heard about Rust compile times being bad but this is an order of magnitude worse than the default settings. While these two options are good rules-of-thumb for a minimally-sized build not everyone falls into the category of needing a minimally sized build, and users can always configure this themselves. * `debug = false` is not necessary as it's already the default of the `profile.release` in Cargo. * `strip = true` is no longer necessary in recent versions of rustc/Cargo because this is done by default for debuginfo. This is otherwise somewhat harmful as it strips the `name` custom section which hinders any after-the-fact analysis of a binary because there is no symbol information to profile with, for example. * `opt-level = "s"` is not universally smaller than the default `opt-level = "3"` and it can also perform significantly worse. An example component I was working with today had a 100% slowdown using `opt-level = "s"` relative to `opt-level = "3"`. Overall I think it's best to inherit Cargo's and Rust's defaults for these settings by default. There's no one-size-fits-all for all projects which is why Cargo allows configuring things, but for a template I think it's best to inherit default settings since that'll ideally cause the least surprise for users who aren't otherwise familiar with these settings.

This commit effectively reverts #289 and removes the generated `[profile.release]` section from `Cargo.toml` when executing `cargo component new`. The PR mentions that a default release build decreases from 1.6M to 52KB and that was likely due to stripping DWARF debugging information rather than many of the other settings configured. Nowadays for example a default release build (with no extra configuration and no `profile.release`) is around 50KB because rustc/cargo have started stripping debuginfo by default in release mode. That means that the original motivation is still solved, the "default" build is not an alarmingly large 1.6M. Otherwise the various settings configured here can have negative effects which aren't always easy to debug if you're not familiar with them, for example: * `lto = true` and `codegen-units = 1` can massively increase the time needed for a build. This can be surprising to newcomers who may have heard about Rust compile times being bad but this is an order of magnitude worse than the default settings. While these two options are good rules-of-thumb for a minimally-sized build not everyone falls into the category of needing a minimally sized build, and users can always configure this themselves. * `debug = false` is not necessary as it's already the default of the `profile.release` in Cargo. * `strip = true` is no longer necessary in recent versions of rustc/Cargo because this is done by default for debuginfo. This is otherwise somewhat harmful as it strips the `name` custom section which hinders any after-the-fact analysis of a binary because there is no symbol information to profile with, for example. * `opt-level = "s"` is not universally smaller than the default `opt-level = "3"` and it can also perform significantly worse. An example component I was working with today had a 100% slowdown using `opt-level = "s"` relative to `opt-level = "3"`. Overall I think it's best to inherit Cargo's and Rust's defaults for these settings by default. There's no one-size-fits-all for all projects which is why Cargo allows configuring things, but for a template I think it's best to inherit default settings since that'll ideally cause the least surprise for users who aren't otherwise familiar with these settings.

for cargo component new generated Cargo.toml adds a good default …

0b08318

…`release.profile`

calvinrp changed the title ~~Add release.profile to Cargo.toml generated by cargo component new~~ Add profile.release to Cargo.toml generated by cargo component new May 6, 2024

fibonacci1729 approved these changes May 7, 2024

View reviewed changes

fibonacci1729 merged commit e65e553 into bytecodealliance:main May 7, 2024
6 checks passed

calvinrp deleted the new-updated-release-profile branch May 7, 2024 18:51

alexcrichton mentioned this pull request Jan 14, 2025

Remove generated [profile.release] from new projects #369

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add `profile.release` to `Cargo.toml` generated by `cargo component new` #289

Add `profile.release` to `Cargo.toml` generated by `cargo component new` #289

calvinrp commented May 6, 2024 •

edited

Loading

calvinrp commented May 7, 2024

Add profile.release to Cargo.toml generated by cargo component new #289

Add profile.release to Cargo.toml generated by cargo component new #289

Conversation

calvinrp commented May 6, 2024 • edited Loading

calvinrp commented May 7, 2024

Add `profile.release` to `Cargo.toml` generated by `cargo component new` #289

Add `profile.release` to `Cargo.toml` generated by `cargo component new` #289

calvinrp commented May 6, 2024 •

edited

Loading