WIP: Migrate wasmer-cli to clap from structopt

[silwol]

Description

Review

• Add a short description of the change to the CHANGELOG.md file

[syrusakbary]

Undo this plz

[syrusakbary]

It looks good other than the removal of the rust-toolchain file.
Once it's fixed we should be good to merge

[silwol]

There's still a few TODOs in the change that I'd like to have clarified first, that's why it is still a draft MR. The removal of the toolchain file will not be part of the final version of this MR of course, as has nothing to do with it.

[epilys]

I'd like to see a binary size of clap and structopt as well, out of curiosity.

[ptitSeb]

What about cli-compiler?

[silwol]

@ptitSeb you're right, had a newer version of the branch including cli-compiler on my disk, force-pushed it now.
@epilys will collect a few numbers regarding binary size.
Didn't expect the MR to get that much attention while still in draft state. :-)

[silwol]

@epilys here are the numbers for changes in binary size (measured on my x64 desktop computer with Debian 11, without llvm compiler enabled, but I think that shouldn't change a lot in this context).

For transparency, this is how I collected the information:

# make sure we start clean
rm -rf target

# build wasmer cli (cranelift + singlepass, no llvm)
cargo build --release --manifest-path lib/cli/Cargo.toml --features cranelift,singlepass --bin wasmer

# build wasmer-headless cli
cargo build --release --manifest-path lib/cli/Cargo.toml --features headless --bin wasmer-headless

# build cli-compiler
cargo build --release --manifest-path lib/cli-compiler/Cargo.toml

# show filesize before stripping
echo "before stripping"
ls -l target/release/wasmer{,-headless,-compiler}

# strip the binaries
strip target/release/wasmer{,-headless,-compiler}

# show filesize after stripping
echo "after stripping"
ls -l target/release/wasmer{,-headless,-compiler}

Raw release binaries

All raw numbers in the tabe are sizes in bytes.

	structopt	clap	absolute change	relative change
wasmer	18334632	18299344	-35288	-0.19%
wasmer-compiler	4896048	4839632	-56416	-1.15%
wasmer-headless	12309944	12268000	-41944	-0.34%

Stripped release binaries

All raw numbers in the tabe are sizes in bytes.

	structopt	clap	absolute change	relative change
wasmer	11744824	11707960	-36864	-0.31%
wasmer-compiler	1304984	1251736	-53248	-4.08%
wasmer-headless	6780424	6739464	-40960	-0.60%

[silwol]

Superseded by #3079