Making Rust binaries smaller by default (kobzol.github.io)

submitted 7 months ago by morrowind@lemmy.ml to c/rust@programming.dev

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Upto 90% for hellworld

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[-] robinm@programming.dev 9 points 7 months ago

It's also what I understood from what I read but I assume it was just a poor choice of word. Debug symbols are way too important for debugging to be stripped by default.

[-] Lmaydev@programming.dev 5 points 7 months ago

In fact, this new default will be used for any profile which does not enable debuginfo anywhere in its dependency chain, not just for the release profile.

On reflection I imagine the debug profile does enable this

[-] robinm@programming.dev 4 points 7 months ago

Yeah, this make sence

[-] OmnipotentEntity@beehaw.org 4 points 7 months ago* (last edited 7 months ago)

As mentioned in the article, this concerns release mode, which already does not have symbols by default for user code. It does have symbols for the standard library code, however, due to how the binaries for the standard library are shipped (i.e. with symbols only). This change simply also removes standard library symbols.

If you need symbols, you can use default debugging build, or if you need both compiler optimizations and debugging symbols you can create a custom profile that inherets from release with debug = true. The second you already need to do to get full debugging symbols right now, so this isn't really much of a change from a workflow standpoint.

[-] Lmaydev@programming.dev 2 points 7 months ago* (last edited 7 months ago)

In fact, this new default will be used for any profile which does not enable debuginfo anywhere in its dependency chain, not just for the release profile.

This is the sentence that tripped me up. But on rereading I'm assuming the debug profile does enable this.

[-] OmnipotentEntity@beehaw.org 3 points 7 months ago

Yeah, definitely :)

The default dev profile is defined as:

[profile.dev]
opt-level = 0
debug = true
split-debuginfo = '...'  # Platform-specific.
strip = "none"
debug-assertions = true
overflow-checks = true
lto = false
panic = 'unwind'
incremental = true
codegen-units = 256
rpath = false

You can find more information in the cargo book page on profiles