Hack for "unsafety hygiene" -- `push_unsafe!` and `pop_unsafe!`.

Even after expansion, the generated expressions still track depth of
such pushes (i.e. how often you have "pushed" without a corresponding
"pop"), and we add a rule that in a context with a positive
`push_unsafe!` depth, it is effectively an `unsafe` block context.

(This way, we can inject code that uses `unsafe` features, but still
contains within it a sub-expression that should inherit the outer
safety checking setting, outside of the injected code.)

This is a total hack; it not only needs a feature-gate, but probably
should be feature-gated forever (if possible).

ignore-pretty in test/run-pass/pushpop-unsafe-okay.rs

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index d93af5da13c..5424c0b214a 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -120,6 +120,7 @@ pub mod ext {
     pub mod log_syntax;
     pub mod mtwt;
     pub mod quote;
+    pub mod pushpop_safe;
     pub mod source_util;
     pub mod trace_macros;