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
adjusting a few foreign functions that were declared with by-ref
mode. This also allows us to remove by-val mode in the near future.
With copy mode, though, we have to be careful because Rust will implicitly pass
somethings by pointer but this may not be the C ABI rules. For example, rust
will pass a struct Foo as a Foo*. So I added some code into the adapters to
fix this (though the C ABI rules may put the pointer back, oh well).
This patch also includes a lint mode for the use of by-ref mode
in foreign functions as the semantics of this have changed.
Continuing #5140
For the sake of getting this merged I've disabled debuginfo tests on mac (where running gdb needs root). Please feel free to follow up with further improvements.
r? @graydon
This removes `log` from the language. Because we can't quite implement it as a syntax extension (probably need globals at the least) it simply renames the keyword to `__log` and hides it behind macros.
After this the only way to log is with `debug!`, `info!`, etc. I figure that if there is demand for `log!` we can add it back later.
I am not sure that we ever agreed on this course of action, though I *think* there is consensus that `log` shouldn't be a statement.
