Before it wouldn't warn about unused imports in the list if something in the list was used. These commits fix that case, add a test, and remove all unused imports in lists of imports throughout the compiler.
re bug that @nikomatsakis was hitting: when you define a `static` (old: `const`) containing a `&` or `&[]` expression, it will create temporaries (the underlying pointee) by creating a throwaway symbol for each temporary, each with _global_ linkage, and each named `"const"`. LLVM will helpfully rename multiple copies of this throwaway symbol to `"const1"` and `"const2"` and so forth in the _same_ library. But if you have _2 libraries_ -- say, libcore and librustc -- that both do this, the dynamic linker (at least on linux) will happily do horrible things like make the slice in one library point to the bytes of the vector from the other library. This is obviously a recipe for much hilarity and head-scratching.
The solution is to change the linkage to something else, internal or (in the case of this patch) _private_.
It will require a snapshot to integrate this into stage0 and thereby fix the problem / unblock patches that were hitting this in stage1.
Before, if anything in a list was used, the entire list was considered to be
used. This corrects this and also warns on a span of the actual unused import
instead of the entire list.
Impose a limit so that the typo suggester only shows reasonable
suggestions (i.e. don't suggest `args` when the error is `foobar`).
A tiny bit of progress on #2281.
Hey folks,
This patch series does some work on the json decoder, specifically with auto decoding of enums. Previously, we would take this code:
```
enum A {
B,
C(~str, uint)
}
```
and would encode a value of this enum to either `["B", []]` or `["C", ["D", 123]]`. I've changed this to `"B"` or `["C", "D", 123]`. This matches the style of the O'Caml json library [json-wheel](http://mjambon.com/json-wheel.html). I've added tests to make sure all this work.
In order to make this change, I added passing a `&[&str]` vec to `Decode::emit_enum_variant` so the json decoder can convert the name of a variant into it's position. I also changed the impl of `Encodable` for `Option<T>` to have the right upper casing.
I also did some work on the parser, which allows for `fn foo<T: ::cmp::Eq>() { ... }` statements (#5572), fixed the pretty printer properly expanding `debug!("...")` expressions, and removed `ast::expr_vstore_fixed`, which doesn't appear to be used anymore.
the types. Initially I thought it would be necessary to thread this data
through not only the AST but the types themselves, but then I remembered that
the pretty printer only cares about the AST. Regardless, I have elected to
leave the changes to the types intact since they will eventually be needed. I
left a few FIXMEs where it didn't seem worth finishing up since the code wasn't
crucial yet.
Because the json::Decoder uses the string variant name, we need a
way to correlate the string to the enum index. This passes in a
static &[&str] to read_enum_variant, which allows the json::Decoder
to know which branch it's trying to process.
Various FIXME comments added around to denote copies which when removed cause
the compiler to segfault at some point before stage2. None of these copies
should even be necessary.
- Most functions that used to return `~[~str]` for a list of substrings got turned into iterators over `&str` slices
- Some cleanup of apis, docs and code layout
