Significant progress on #6875, enough that I'll open new bugs and turn that into a metabug when this lands.
Description & example in the commit message.
There are 6 new compiler recognised attributes: deprecated, experimental,
unstable, stable, frozen, locked (these levels are taken directly from
Node's "stability index"[1]). These indicate the stability of the
item to which they are attached; e.g. `#[deprecated] fn foo() { .. }`
says that `foo` is deprecated.
This comes with 3 lints for the first 3 levels (with matching names) that
will detect the use of items marked with them (the `unstable` lint
includes items with no stability attribute). The attributes can be given
a short text note that will be displayed by the lint. An example:
#[warn(unstable)]; // `allow` by default
#[deprecated="use `bar`"]
fn foo() { }
#[stable]
fn bar() { }
fn baz() { }
fn main() {
foo(); // "warning: use of deprecated item: use `bar`"
bar(); // all fine
baz(); // "warning: use of unmarked item"
}
The lints currently only check the "edges" of the AST: i.e. functions,
methods[2], structs and enum variants. Any stability attributes on modules,
enums, traits and impls are not checked.
[1]: http://nodejs.org/api/documentation.html
[2]: the method check is currently incorrect and doesn't work.
Fix#8468. (Though the right answer in the end, as noted on the dialogue on the ticket, might be to just require trait methods to name their parameters, regardless of whether they have a default method implementation or not.)
As with the previous commit, this is targeted at removing the possibility of
collisions between statics. The main use case here is when there's a
type-parametric function with an inner static that's compiled as a library.
Before this commit, any impl would generate a path item of "__extensions__".
This changes this identifier to be a "pretty name", which is either the last
element of the path of the trait implemented or the last element of the type's
path that's being implemented. That doesn't quite cut it though, so the (trait,
type) pair is hashed and again used to append information to the symbol.
Essentially, __extensions__ was removed for something nicer for debugging, and
then some more information was added to symbol name by including a hash of the
trait being implemented and type it's being implemented for. This should prevent
colliding names for inner statics in regular functions with similar names.
Before, the path name for all items defined in methods of traits and impls never
took into account the name of the method. This meant that if you had two statics
of the same name in two different methods the statics would end up having the
same symbol named (even after mangling) because the path components leading to
the symbol were exactly the same (just __extensions__ and the static name).
It turns out that if you add the symbol "A" twice to LLVM, it automatically
makes the second one "A1" instead of "A". What this meant is that in local crate
compilations we never found this bug. Even across crates, this was never a
problem. The problem arises when you have generic methods that don't get
generated at compile-time of a library. If the statics were re-added to LLVM by
a client crate of a library in a different order, you would reference different
constants (the integer suffixes wouldn't be guaranteed to be the same).
This fixes the problem by adding the method name to symbol path when building
the ast_map. In doing so, two symbols in two different methods are disambiguated
against.
This removes the stacking of type parameters that occurs when invoking
trait methods, and fixes all places in the standard library that were
relying on it. It is somewhat awkward in places; I think we'll probably
want something like the `Foo::<for T>::new()` syntax.
Fixes for #8625 to prevent assigning to `&mut` in borrowed or aliasable locations. The old code was insufficient in that it failed to catch bizarre cases like `& &mut &mut`.
r? @pnkfelix
These new macros are all based on format! instead of fmt! and purely exist for
bootstrapping purposes. After the next snapshot, all uses of logging will be
migrated to these macros, and then after the next snapshot after that we can
drop the `2` suffix on everything
Long-standing branch to remove foreign function wrappers altogether. Calls to C functions are done "in place" with no stack manipulation; the scheme relies entirely on the correct use of `#[fixed_stack_segment]` to guarantee adequate stack space. A linter is added to detect when `#[fixed_stack_segment]` annotations are missing. An `externfn!` macro is added to make it easier to declare foreign fns and wrappers in one go: this macro may need some refinement, though, for example it might be good to be able to declare a group of foreign fns. I leave that for future work (hopefully somebody else's work :) ).
Fixes#3678.
See discussion in #8489, but this selects option 3 by adding a `Default` trait to be implemented by various basic types.
Once this makes it into a snapshot I think it's about time to start overhauling all current use-cases of `fmt!` to move towards `ifmt!`. The goal is to replace `%X` with `{}` in 90% of situations, and this commit should enable that.
The span was fixed at some point to point to the correct character, but
the error message is still bad. Update it to emit the actual character
in question (potentially escaped).
Fixes#3747.
When parsing a trait function, the function must end with either `;` or
`{` (signifying a default implementation). The error message incorrectly
stated that it must be `;` or `}`.
Fixes#6610.