diff --git a/Cargo.lock b/Cargo.lock
index 551cd8634754a1e32ef00350f25293537e172581..7c0b7813164fd038d1b733223654d222a47ea833 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -176,6 +176,7 @@ dependencies = [
"regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
"smallstring 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
"smallvec 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "take_mut 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
"unicode-segmentation 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
"users 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
"version_check 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -209,7 +210,7 @@ dependencies = [
[[package]]
name = "liner"
version = "0.4.5"
-source = "git+https://gitlab.redox-os.org/redox-os/liner#98f723d1501701a659ab998226d7f5b32098ffc2"
+source = "git+https://gitlab.redox-os.org/redox-os/liner#82c1715faffe2535f0e9a5bc379c5c0230a360fe"
dependencies = [
"bytecount 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
"termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -354,6 +355,11 @@ dependencies = [
"syn 0.11.11 (registry+https://github.com/rust-lang/crates.io-index)",
]
+[[package]]
+name = "take_mut"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
[[package]]
name = "termion"
version = "1.5.1"
@@ -506,6 +512,7 @@ source = "git+https://github.com/whitequark/rust-xdg#090afef2509d746e48d6bfa9b2e
"checksum syn 0.11.11 (registry+https://github.com/rust-lang/crates.io-index)" = "d3b891b9015c88c576343b9b3e41c2c11a51c219ef067b264bd9c8aa9b441dad"
"checksum synom 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a393066ed9010ebaed60b9eafa373d4b1baac186dd7e008555b0f702b51945b6"
"checksum synstructure 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3a761d12e6d8dcb4dcf952a7a89b475e3a9d69e4a69307e01a470977642914bd"
+"checksum take_mut 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f764005d11ee5f36500a149ace24e00e3da98b0158b3e2d53a7495660d3f4d60"
"checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
"checksum textwrap 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0b59b6b4b44d867f1370ef1bd91bfb262bf07bf0ae65c202ea2fbc16153b693"
"checksum thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "279ef31c19ededf577bfd12dfae728040a21f635b06a24cd670ff510edd38963"
diff --git a/Cargo.toml b/Cargo.toml
index 82cbe48f66ba72a7a7f7cf14822ea6a78749c81c..53679b83c4d154f1e1e21d37679a60ab8b4a1449 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,6 +42,7 @@ smallstring = "0.1"
smallvec = "0.6"
unicode-segmentation = "1.2"
xdg = { git = "https://github.com/whitequark/rust-xdg" }
+take_mut = "0.2.2"
[lib]
path = "src/lib/lib.rs"
diff --git a/src/lib/lib.rs b/src/lib/lib.rs
index 6cea2825c4b1e0d10bdaa45b935213e1a90e9d65..db4de8723f26b09e4790f3dbd3e4ce67c458f4bb 100644
--- a/src/lib/lib.rs
+++ b/src/lib/lib.rs
@@ -17,6 +17,7 @@ extern crate glob;
extern crate itoa;
#[macro_use]
extern crate lazy_static;
+extern crate take_mut;
#[cfg(test)]
extern crate test;
#[cfg(all(unix, not(target_os = "redox")))]
diff --git a/src/lib/shell/flow.rs b/src/lib/shell/flow.rs
index 8847dd57ff8d5dd6aff125db293529d94c10134f..022ca5524c7e8e10ac5a2d093a1844691e5fc548 100644
--- a/src/lib/shell/flow.rs
+++ b/src/lib/shell/flow.rs
@@ -608,17 +608,7 @@ impl FlowLogic for Shell {
}
fn execute_statements(&mut self, mut statements: Vec<Statement>) -> Condition {
- self.with_vars(|old: &Variables| {
- let new = old.new_scope();
- // TODO: THIS IS SUPER UNSAFE!!!!!11111
- // I'm bypassing the borrow checker here because I'm too gosh darn lazy
- // to make Shell take a lifetime pararmeter.
- // THIS. IS. WRONG.
- // This should be fixed. Some day. Ugh.
- // Don't do this at home, kids!
- let new: Variables<'static> = unsafe { mem::transmute(new) };
- new
- }, |shell| {
+ self.with_vars(|old: &Variables| old.new_scope(), |shell| {
let mut iterator = statements.drain(..);
while let Some(statement) = iterator.next() {
match shell.execute_statement(&mut iterator, statement) {
diff --git a/src/lib/shell/flow_control.rs b/src/lib/shell/flow_control.rs
index 948cdc08a8af497e0d86b7cf911323ae186291f1..9649417f6975b3dc4f97f6e72c9dd974a76ba6a3 100644
--- a/src/lib/shell/flow_control.rs
+++ b/src/lib/shell/flow_control.rs
@@ -1,8 +1,7 @@
-use super::{flow::FlowLogic, Shell, Variables};
+use super::{flow::FlowLogic, Shell};
use parser::{assignments::*, pipelines::Pipeline};
use smallvec::SmallVec;
use std::fmt::{self, Display, Formatter};
-use std::mem;
use types::Identifier;
#[derive(Debug, PartialEq, Clone)]
@@ -195,15 +194,7 @@ impl Function {
while !vars.functions.borrow().contains_key(&name) {
vars = vars.parent.expect("execute called on function that's not in scope");
}
- let vars = vars.new_scope();
- // TODO: THIS IS SUPER UNSAFE!!!!!11111
- // I'm bypassing the borrow checker here because I'm too gosh darn lazy
- // to make Shell take a lifetime pararmeter.
- // THIS. IS. WRONG.
- // This should be fixed. Some day. Ugh.
- // Don't do this at home, kids!
- let vars: Variables<'static> = unsafe { mem::transmute(vars) };
- vars
+ vars.new_scope()
}, move |shell| {
for (type_, value) in values {
match value {
diff --git a/src/lib/shell/mod.rs b/src/lib/shell/mod.rs
index 35100d28718c7e63f8118a956d297e1e6a3f42b9..ffdf5bf0691a8d5d258b6d2f11114703e796778f 100644
--- a/src/lib/shell/mod.rs
+++ b/src/lib/shell/mod.rs
@@ -36,10 +36,11 @@ use liner::Context;
use parser::{pipelines::Pipeline, ArgumentSplitter, Expander, Select, Terminator};
use smallvec::SmallVec;
use std::{
- fs::File, io::{self, Read, Write}, iter::FromIterator, mem, ops::Deref, path::Path, ptr, process,
+ fs::File, io::{self, Read, Write}, iter::FromIterator, mem, ops::Deref, path::Path, process,
sync::{atomic::Ordering, Arc, Mutex}, time::SystemTime,
};
use sys;
+use take_mut;
use types::*;
use xdg::BaseDirectories;
@@ -171,17 +172,25 @@ impl<'a> Shell {
/// A method for temporarily using a separate set of variables for this shell.
/// Calls the inner callback and then swaps back.
pub fn with_vars<VF, F, T>(&mut self, variables: VF, callback: F) -> T
- where VF: FnOnce(&Variables) -> Variables<'static>,
+ where VF: for <'b> FnOnce(&'b Variables) -> Variables<'b>,
F: FnOnce(&mut Self) -> T
{
- // TODO: It's undefined behavior if variables() callback panics.
- // This could be solved with the take-mut crate.
- let old = mem::replace(&mut self.variables, unsafe { mem::uninitialized() });
- let new = variables(&old);
- unsafe { ptr::write(&mut self.variables, new); }
-
+ let mut old = None;
+ take_mut::take(&mut self.variables, |old2| {
+ old = Some(old2);
+ let new = variables(old.as_ref().unwrap());
+
+ // TODO: THIS IS SUPER UNSAFE!!!!!11111
+ // I'm bypassing the borrow checker here because I'm too gosh darn lazy
+ // to make Shell take a lifetime pararmeter.
+ // THIS. IS. WRONG.
+ // This should be fixed. Some day. Ugh.
+ // Don't do this at home, kids!
+ let new: Variables<'static> = unsafe { mem::transmute(new) };
+ new
+ });
let value = callback(self);
- mem::replace(&mut self.variables, old);
+ mem::replace(&mut self.variables, old.unwrap());
value
}