On 12/15/2013 07:52 AM, Liigo Zhuang wrote:
Rust compiler compiles "crates", rustpkg manages "packages".
When develope a library for rust, I write these code in lib.rs
<http://lib.rs>:
```
#[pkgid = "whoami"];
#[crate_type = "lib"];
…………
```
Note, I set its "package" id, and set its "crate" type, and it is
compiled to an .so library. Now please tell me, what "it" is? A package?
A crate? or just a library? If it's a package, why I set its crate type?
If it's a crate, why I set its package id? Confusing.
I agree that 'pkgid' is a really unfortunate name that stems from the
confusion of whether or not a package is allowed to contain multiple
crates. I think it should, but it feels like I'm in a minority. 'pkgid'
is used to generate the crate output name, at least for libraries, (i.e.
lib<name>-<hash>-<version>.so). Frankly, I liked the old link metadata
idea better where you specified the Author, Version and output name
separately, and it was not conflated with the rustpkg idea. I believe
the movement to #[pkgid] was driven by the desire for external tools to
be able to compute the hash (e.g. see
http://metajack.im/2013/12/12/building-rust-code--using-make/)... but I
think that's a mistake. I really don't think this is a solution:
RUST_CRATE_PKGID = $(shell sed -ne 's/^#[ *pkgid *= *"(.*)" *];$$/\1/p'
$(firstword $(1)))
RUST_CRATE_HASH = $(shell printf $(strip $(1)) | shasum -a 256 | sed -ne
's/^(.{8}).*$$/\1/p')
_rust_crate_pkgid = $$(call RUST_CRATE_PKGID, $$(_rust_crate_lib))
_rust_crate_hash = $$(call RUST_CRATE_HASH, $$(_rust_crate_pkgid))
I'd rather just do:
RUST_CRATE_HASH = $(shell rustc --get-crate-hash $1)
_rust_crate_hash = $$(call RUST_CRATE_HASH, $$(_rust_crate_lib))
Personally, I'd remove the notion of a package id from the language, and
leave it entirely up to the external package management tool to deal with.
That'd mean the removal of the unfortunate `extern mod foo = "pkgid";`
syntax which conflates crates and packages (it could be replaced with
`#[pkgid="pkgid"] extern mod foo;` if source annotation of external
dependencies is really desired. It'd have to have different semantics in
order not to repeat the confusion.).
And when use it ("whoami"), I must write the code:
```
extern mod whoami;
```
Now was it transmuted to a "module"?? If it's a module, why I haven't
set its module id and module type? If it's not a module, why not use
`extern package whoami` or `extern crate whoami` here? Full of confusion.
Can you please tell me WHAT it really is? Thank you.
For what it is worth, "extern mod" is slated to be changed to be
"crate", I think: https://github.com/mozilla/rust/issues/9880 .
-SL
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