Reduce rustbuild bloat caused by serde_derive #94844
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bjorn3
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☔ The latest upstream changes (presumably #94845) made this pull request unmergeable. Please resolve the merge conflicts. |
This reduces binary size from 10.1MiB (6.2MiB for just rustbuild code) to 9.7MiB (5.8MiB for just rustbuild code). This also reduces compile time from ~6.1s for incr recompilation to ~5.6s. There is still a lot of unnecessary code due to the toml crate monomorphizing every deserialization impl 5 times.
This reduces binary size from 9.7MiB (5.8MiB for just rustbuild code) to 9.3MiB (5.3MiB for just rustbuild code). This doesn't reduce compile time in a statistically significant way.
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Generally seems OK, though it does seem unfortunate to lose the nicer ergonomics offered by serde-derive. Ultimately we're not really using them so it's probably OK.
I am a little surprised to see that the dependency on serde derive isn't entirely dropped -- is that because it's still being used by metadata or something else? Do you expect to drop that eventually?
Mark-Simulacrum
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It is still used in a couple of other places like cargo artifact message deserialization and toolstate serialization/deserialization. I want to remove these too, but I focused on config deserialization first as it has the best cost vs benefit ratio. |
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FWIW, if we care about disk space, it's probably worth comparing against an optimized build (at least -O1) of bootstrap and see what the size vs. time tradeoff is. But regardless, this seems good to me -- r=me if you don't want to iterate further in this PR. |
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My main motivation for reducing this bloat is actually reducing compilation time. Smaller binaries generally take less time to codegen and less time to link. Reducing the total disk usage is a nice side-effect. By the way final stats for text section size: 4.9MiB for just rustbuild code. 8.8MiB for the whole binary. @bors r=Mark-Simulacrum |
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…askrgr Rollup of 5 pull requests Successful merges: - rust-lang#93292 (Implement `BITS` constant for non-zero integers) - rust-lang#94777 (Update armv7-unknown-linux-uclibceabi platform support page.) - rust-lang#94816 (Add `Atomic*::get_mut_slice`) - rust-lang#94844 (Reduce rustbuild bloat caused by serde_derive) - rust-lang#94907 (Omit stdarch test crates from the rust-src component) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
This reduces the size of the
.textsection from 10.1MiB (6.2MiB for just rustbuild code) to 9.3MiB (5.3MiB for just rustbuild code).This also reduces compile time from ~6.1s for incr recompilation to ~5.6s.
r? @Mark-Simulacrum