These two containers are indeed collections, so their place is in
libcollections, not in libstd. There will always be a hash map as part of the
standard distribution of Rust, but by moving it out of the standard library it
makes libstd that much more portable to more platforms and environments.
This conveniently also removes the stuttering of 'std::hashmap::HashMap',
although 'collections::HashMap' is only one character shorter.
This patch replaces all `crate` usage with `krate` before introducing the
new keyword. This ensures that after introducing the keyword, there
won't be any compilation errors.
krate might not be the most expressive substitution for crate but it's a
very close abbreviation for it. `module` was already used in several
places already.
Major changes:
- Define temporary scopes in a syntax-based way that basically defaults
to the innermost statement or conditional block, except for in
a `let` initializer, where we default to the innermost block. Rules
are documented in the code, but not in the manual (yet).
See new test run-pass/cleanup-value-scopes.rs for examples.
- Refactors Datum to better define cleanup roles.
- Refactor cleanup scopes to not be tied to basic blocks, permitting
us to have a very large number of scopes (one per AST node).
- Introduce nascent documentation in trans/doc.rs covering datums and
cleanup in a more comprehensive way.
r? @pcwalton
Major changes:
- Define temporary scopes in a syntax-based way that basically defaults
to the innermost statement or conditional block, except for in
a `let` initializer, where we default to the innermost block. Rules
are documented in the code, but not in the manual (yet).
See new test run-pass/cleanup-value-scopes.rs for examples.
- Refactors Datum to better define cleanup roles.
- Refactor cleanup scopes to not be tied to basic blocks, permitting
us to have a very large number of scopes (one per AST node).
- Introduce nascent documentation in trans/doc.rs covering datums and
cleanup in a more comprehensive way.
The `print!` and `println!` macros are now the preferred method of printing, and so there is no reason to export the `stdio` functions in the prelude. The functions have also been replaced by their macro counterparts in the tutorial and other documentation so that newcomers don't get confused about what they should be using.
### Rationale
There is no reason to support more than 2³² nodes or names at this moment, as compiling something that big (even without considering the quadratic space usage of some analysis passes) would take at least **64GB**.
Meanwhile, some can't (or barely can) compile rustc because it requires almost **1.5GB**.
### Potential problems
Can someone confirm this doesn't affect metadata (de)serialization? I can't tell myself, I know nothing about it.
### Results
Some structures have a size reduction of 25% to 50%: [before](https://gist.github.com/luqmana/3a82a51fa9c86d9191fa) - [after](https://gist.github.com/eddyb/5a75f8973d3d8018afd3).
Sadly, there isn't a massive change in the memory used for compiling stage2 librustc (it doesn't go over **1.4GB** as [before](http://huonw.github.io/isrustfastyet/mem/), but I can barely see the difference).
However, my own testcase (previously peaking at **1.6GB** in typeck) shows a reduction of **200**-**400MB**.
This commit fixes all of the fallout of the previous commit which is an attempt
to refine privacy. There were a few unfortunate leaks which now must be plugged,
and the most horrible one is the current `shouldnt_be_public` module now inside
`std::rt`. I think that this either needs a slight reorganization of the
runtime, or otherwise it needs to just wait for the external users of these
modules to get replaced with their `rt` implementations.
Other fixes involve making things pub which should be pub, and otherwise
updating error messages that now reference privacy instead of referencing an
"unresolved name" (yay!).
This commit is the culmination of my recent effort to refine Rust's notion of
privacy and visibility among crates. The major goals of this commit were to
remove privacy checking from resolve for the sake of sane error messages, and to
attempt a much more rigid and well-tested implementation of visibility
throughout rust. The implemented rules for name visibility are:
1. Everything pub from the root namespace is visible to anyone
2. You may access any private item of your ancestors.
"Accessing a private item" depends on what the item is, so for a function this
means that you can call it, but for a module it means that you can look inside
of it. Once you look inside a private module, any accessed item must be "pub
from the root" where the new root is the private module that you looked into.
These rules required some more analysis results to get propagated from trans to
privacy in the form of a few hash tables.
I added a new test in which my goal was to showcase all of the privacy nuances
of the language, and I hope to place any new bugs into this file to prevent
regressions.
Overall, I was unable to completely remove the notion of privacy from resolve.
One use of privacy is for dealing with glob imports. Essentially a glob import
can only import *public* items from the destination, and because this must be
done at namespace resolution time, resolve must maintain the notion of "what
items are public in a module". There are some sad approximations of privacy, but
I unfortunately can't see clear methods to extract them outside.
The other use case of privacy in resolve now is one that must stick around
regardless of glob imports. When dealing with privacy, checking a private path
needs to know "what the last private thing was" when looking at a path. Resolve
is the only compiler pass which knows the answer to this question, so it
maintains the answer on a per-path resolution basis (works similarly to the
def_map generated).
Closes#8215
This purges about 500 lines of visitor cruft from lint passes. All lints are
handled in a much more sane way at this point. The other huge bonus of this
commit is that there are no more @-boxes in the lint passes, fixing the 500MB
memory regression seen when the lint passes were refactored.
Closes#8589
