user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Correct IndirectlyMutableLocals docs

Browse source
This commit is contained in:
Dylan MacKenzie 2019-09-25 13:25:06 -07:00
parent a302055caa
commit 8bfe82bfad
1 changed files with 4 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

12
src/librustc_mir/dataflow/impls/indirect_mutation.rs
View file

@ -8,15 +8,11 @@ use crate::dataflow::{self, GenKillSet};
/// Whether a borrow to a `Local` has been created that could allow that `Local` to be mutated
/// indirectly. This could either be a mutable reference (`&mut`) or a shared borrow if the type of
/// that `Local` allows interior mutability.
/// that `Local` allows interior mutability. Operations that can mutate local's indirectly include:
/// assignments through a pointer (`*p = 42`), function calls, drop terminators and inline assembly.
///
/// If this returns false for a `Local` at the location of an indirect assignment, that `Local`
/// cannot be mutated by that assignment. For example, if the dataflow state at a statement like
/// `*p = 42` contained locals `x` and `z` but not `y`, we know that while `x` or `z` may be the
/// target of that assignment, `y` cannot be.
///
/// Assignments through a pointer are not the only place where a `Local` can be mutated indirectly:
/// Function calls, drop terminators and inline assembly can all mutate `Local`s as a side-effect.
/// If this returns false for a `Local` at a given statement (or terminator), that `Local` could
/// not possibly have been mutated indirectly prior to that statement.
#[derive(Copy, Clone)]
pub struct IndirectlyMutableLocals<'mir, 'tcx> {
body: &'mir mir::Body<'tcx>,