1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![allow(non_camel_case_types)]
13 use std::cell::{RefCell, Cell};
14 use std::collections::HashMap;
15 use std::collections::hash_state::HashState;
16 use std::ffi::CString;
19 use std::iter::repeat;
21 use std::time::Duration;
25 use syntax::visit::Visitor;
27 // The name of the associated type for `Fn` return types
28 pub const FN_OUTPUT_NAME: &'static str = "Output";
30 // Useful type to use with `Result<>` indicate that an error has already
31 // been reported to the user, so no need to continue checking.
32 #[derive(Clone, Copy, Debug)]
33 pub struct ErrorReported;
35 pub fn time<T, U, F>(do_it: bool, what: &str, u: U, f: F) -> T where
38 thread_local!(static DEPTH: Cell<usize> = Cell::new(0));
39 if !do_it { return f(u); }
41 let old = DEPTH.with(|slot| {
52 Duration::span(move || {
53 *rvp = Some(f(u.take().unwrap()))
58 println!("{}time: {}.{:03} \t{}", repeat(" ").take(old).collect::<String>(),
59 dur.num_seconds(), dur.num_milliseconds() % 1000, what);
60 DEPTH.with(|slot| slot.set(old));
65 pub fn indent<R, F>(op: F) -> R where
69 // Use in conjunction with the log post-processor like `src/etc/indenter`
70 // to make debug output more readable.
73 debug!("<< (Result = {:?})", r);
78 _cannot_construct_outside_of_this_module: ()
81 impl Drop for Indenter {
82 fn drop(&mut self) { debug!("<<"); }
85 pub fn indenter() -> Indenter {
87 Indenter { _cannot_construct_outside_of_this_module: () }
90 struct LoopQueryVisitor<P> where P: FnMut(&ast::Expr_) -> bool {
95 impl<'v, P> Visitor<'v> for LoopQueryVisitor<P> where P: FnMut(&ast::Expr_) -> bool {
96 fn visit_expr(&mut self, e: &ast::Expr) {
97 self.flag |= (self.p)(&e.node);
99 // Skip inner loops, since a break in the inner loop isn't a
100 // break inside the outer loop
101 ast::ExprLoop(..) | ast::ExprWhile(..) => {}
102 _ => visit::walk_expr(self, e)
107 // Takes a predicate p, returns true iff p is true for any subexpressions
108 // of b -- skipping any inner loops (loop, while, loop_body)
109 pub fn loop_query<P>(b: &ast::Block, p: P) -> bool where P: FnMut(&ast::Expr_) -> bool {
110 let mut v = LoopQueryVisitor {
114 visit::walk_block(&mut v, b);
118 struct BlockQueryVisitor<P> where P: FnMut(&ast::Expr) -> bool {
123 impl<'v, P> Visitor<'v> for BlockQueryVisitor<P> where P: FnMut(&ast::Expr) -> bool {
124 fn visit_expr(&mut self, e: &ast::Expr) {
125 self.flag |= (self.p)(e);
126 visit::walk_expr(self, e)
130 // Takes a predicate p, returns true iff p is true for any subexpressions
131 // of b -- skipping any inner loops (loop, while, loop_body)
132 pub fn block_query<P>(b: &ast::Block, p: P) -> bool where P: FnMut(&ast::Expr) -> bool {
133 let mut v = BlockQueryVisitor {
137 visit::walk_block(&mut v, &*b);
141 /// K: Eq + Hash<S>, V, S, H: Hasher<S>
143 /// Determines whether there exists a path from `source` to `destination`. The
144 /// graph is defined by the `edges_map`, which maps from a node `S` to a list of
145 /// its adjacent nodes `T`.
147 /// Efficiency note: This is implemented in an inefficient way because it is
148 /// typically invoked on very small graphs. If the graphs become larger, a more
149 /// efficient graph representation and algorithm would probably be advised.
150 pub fn can_reach<T, S>(edges_map: &HashMap<T, Vec<T>, S>, source: T,
151 destination: T) -> bool
152 where S: HashState, T: Hash + Eq + Clone,
154 if source == destination {
158 // Do a little breadth-first-search here. The `queue` list
159 // doubles as a way to detect if we've seen a particular FR
160 // before. Note that we expect this graph to be an *extremely
162 let mut queue = vec!(source);
164 while i < queue.len() {
165 match edges_map.get(&queue[i]) {
167 for target in edges {
168 if *target == destination {
172 if !queue.iter().any(|x| x == target) {
173 queue.push((*target).clone());
184 /// Memoizes a one-argument closure using the given RefCell containing
185 /// a type implementing MutableMap to serve as a cache.
187 /// In the future the signature of this function is expected to be:
189 /// pub fn memoized<T: Clone, U: Clone, M: MutableMap<T, U>>(
190 /// cache: &RefCell<M>,
192 /// ) -> impl |T| -> U {
194 /// but currently it is not possible.
199 /// cache: RefCell<HashMap<usize, usize>>
202 /// fn factorial(ctxt: &Context, n: usize) -> usize {
203 /// memoized(&ctxt.cache, n, |n| match n {
205 /// _ => factorial(ctxt, n - 2) + factorial(ctxt, n - 1)
210 pub fn memoized<T, U, S, F>(cache: &RefCell<HashMap<T, U, S>>, arg: T, f: F) -> U
211 where T: Clone + Hash + Eq,
216 let key = arg.clone();
217 let result = cache.borrow().get(&key).cloned();
219 Some(result) => result,
222 cache.borrow_mut().insert(key, result.clone());
229 pub fn path2cstr(p: &Path) -> CString {
230 use std::os::unix::prelude::*;
231 use std::ffi::AsOsStr;
232 CString::new(p.as_os_str().as_bytes()).unwrap()
235 pub fn path2cstr(p: &Path) -> CString {
236 CString::new(p.to_str().unwrap()).unwrap()