Removes a lot of instances of `/*bad*/ copy` throughout libsyntax/librustc. On the plus side, this shaves about 2s off of the runtime when compiling `librustc` with optimizations.
Ideally I would have run a profiler to figure out which copies are the most critical to remove, but in reality there was a liberal amount of `git grep`s along with some spot checking and removing the easy ones.
For bootstrapping purposes, this commit does not remove all uses of
the keyword "pure" -- doing so would cause the compiler to no longer
bootstrap due to some syntax extensions ("deriving" in particular).
Instead, it makes the compiler ignore "pure". Post-snapshot, we can
remove "pure" from the language.
There are quite a few (~100) borrow check errors that were essentially
all the result of mutable fields or partial borrows of `@mut`. Per
discussions with Niko I think we want to allow partial borrows of
`@mut` but detect obvious footguns. We should also improve the error
message when `@mut` is erroneously reborrowed.
This is done in two steps:
First, we make foreign functions not consider modes at all. This is because previously ++ mode was the only way to pass structs to foreign functions and so forth. We also add a lint mode warning if you use `&&` mode in a foreign function, since the semantics of that change (it used to pass a pointer to the C function, now it doesn't).
Then, we remove by value and make it equivalent to `+` mode. At the same time, we stop parsing `-` mode and convert all uses of it to `+` mode (it was already being parsed to `+` mode anyhow).
This obsoletes pull request #5298.
r? @brson
Also converts const cast-from-enum, because it used the same routine to
get the discriminant as what's renovated to construct the enums.
Also fixes ICE on struct-like variants as consts, and provides a slightly
less bad ICE for functional-update-like struct expressions in consts.
This removes all but 6 uses of `drop {}` from the entire codebase. Removing any of the remaining uses causes various non-trivial bugs; I'll start reporting them once this gets merged.
Major changes are:
- replace ~[ty_param] with Generics structure, which includes
both OptVec<TyParam> and OptVec<Lifetime>;
- the use of syntax::opt_vec to avoid allocation for empty lists;
cc #4846
r? @graydon
Major changes are:
- replace ~[ty_param] with Generics structure, which includes
both OptVec<TyParam> and OptVec<Lifetime>;
- the use of syntax::opt_vec to avoid allocation for empty lists;
cc #4846
