r? @therealprof

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Wow, that is a very comprehensive PR, thanks.

I think I should be improving CI before we land this. I have a feeling the formatting is off in parts, did you run rustfmt? Also it would be great to have some automatic regression tests, better than https://github.com/rust-embedded/cargo-binutils/blob/master/ci/script.sh

Yeah my IDE is setup to run rustfmt on file save and it runs clippy for linting.

Agree with the testing. I was thinking it could be a good idea to have a sub-directory with a few different test crates with different structures to check that bin, lib, examples, etc. and combinations of as well as workspaces and such still work correctly.

So I tried using cargo size on cargo-binutils itself:

error: Can only have one matching artifact but found several.
Specified build type: Any
Possible targets:
  cargo size --bench cargo-binutils
  cargo size --bin rust-nm
  cargo size --bin rust-objcopy
  cargo size --bin rust-strip
...

cargo size --bench cargo-binutils doesn't make sense and also doesn't work:

# cargo size --bench cargo-binutils
error: no bench target named `cargo-binutils`
error: Failed to run `cargo build` got exit code: 101
Use `cargo size -v ...` to display the full `cargo build` command

I'm also not happy with the output yet:

error: Can only have one matching artifact but found several.
Specified build type: Any
Possible targets:

Where does the build type come from and what does it mean? And why are we talking about artifacts and targets, we should probably unify the nomenclature here by just talking about targets.

While experimenting with this I just noticed that the help generated by the CLI parser is off, but that can be addressed separately:

# cargo size --bin
error: The argument '--bin <NAME>' requires a value but none was supplied

USAGE:
    cargo-size <binary-name> --bin <NAME>

For more information try --help

So I tried using cargo size on cargo-binutils itself:

error: Can only have one matching artifact but found several.
Specified build type: Any
Possible targets:
  cargo size --bench cargo-binutils
  cargo size --bin rust-nm
  cargo size --bin rust-objcopy
  cargo size --bin rust-strip
...

cargo size --bench cargo-binutils doesn't make sense and also doesn't work:

# cargo size --bench cargo-binutils
error: no bench target named `cargo-binutils`
error: Failed to run `cargo build` got exit code: 101
Use `cargo size -v ...` to display the full `cargo build` command

oh, woops. Yeah bad copy paste. Is supposed to be --lib
https://github.com/rust-embedded/cargo-binutils/pull/86/files#diff-b4aea3e418ccdb71239b96952d9cddb6R88

I'm also not happy with the output yet:

error: Can only have one matching artifact but found several.
Specified build type: Any
Possible targets:

Where does the build type come from and what does it mean? And why are we talking about artifacts and targets, we should probably unify the nomenclature here by just talking about targets.

Yep will do a pass and change it to use target.

While experimenting with this I just noticed that the help generated by the CLI parser is off, but that can be addressed separately:

# cargo size --bin
error: The argument '--bin <NAME>' requires a value but none was supplied

USAGE:
    cargo-size <binary-name> --bin <NAME>

For more information try --help

hmm, yeah opened an issue for it.

I'm also not happy with the output yet:

error: Can only have one matching artifact but found several.
Specified build type: Any
Possible targets:

Where does the build type come from and what does it mean?

The build type the argument provided, --lib, --bin <target>, etc.
It probably should get changed to only display if verbose output is enabled.

# cargo size
    Finished dev [unoptimized + debuginfo] target(s) in 0.09s
error: Can only have one matching target but found several.
Specified build type: Any
Possible targets:
  cargo size --lib cargo-binutils
  cargo size --bin cargo-size
  cargo size --bin cargo-objcopy
  cargo size --bin rust-objdump
  cargo size --bin rust-ar
  cargo size --bin rust-size
  cargo size --bin rust-ld
  cargo size --bin cargo-profdata
  cargo size --bin cargo-readobj
  cargo size --bin cargo-objdump
  cargo size --bin rust-lld
  cargo size --bin rust-readobj
  cargo size --bin cargo-nm
  cargo size --bin rust-objcopy
  cargo size --bin rust-nm
  cargo size --bin rust-profdata
  cargo size --bin rust-strip
  cargo size --bin cargo-strip
# cargo size --lib cargo-binutils
error: Found argument 'cargo-binutils' which wasn't expected, or isn't valid in this context

USAGE:
    cargo-size <binary-name> --lib

For more information try --help

😅

It also does surprising things on embedded projects now, e.g. when trying on the stm32f0xx-hal:

# cargo size --features="stm32f072,rt"
    Finished dev [unoptimized + debuginfo] target(s) in 0.04s
   text	   data	    bss	    dec	    hex	filename
   3306	      0	      0	   3306	    cea	stm32f0xx_hal-8764f603c6f243ae.15sok97r09wqx69d.rcgu.o (ex libstm32f0xx_hal.rlib)
     36	      0	      0	     36	     24	stm32f0xx_hal-8764f603c6f243ae.15vhf19n6ff33qjb.rcgu.o (ex libstm32f0xx_hal.rlib)
    214	      0	      0	    214	     d6	stm32f0xx_hal-8764f603c6f243ae.16g95b23l0dtk6k2.rcgu.o (ex libstm32f0xx_hal.rlib)
    144	      0	      0	    144	     90	stm32f0xx_hal-8764f603c6f243ae.16jw9k5j7mogltir.rcgu.o (ex libstm32f0xx_hal.rlib)
...

I certainly would not expect this to list the size of random anonymous compiler units...

Any update on this? I just got a vague error message error: Could not determine the wanted artifact and presumably this PR would improve on that error message