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| {
51 Duration::span(move || {
57 // Hack up our own formatting for the duration to make it easier for scripts
58 // to parse (always use the same number of decimal places and the same unit).
59 const NANOS_PER_SEC: f64 = 1_000_000_000.0;
60 let secs = dur.secs() as f64;
61 let secs = secs + dur.extra_nanos() as f64 / NANOS_PER_SEC;
62 println!("{}time: {:.3} \t{}", repeat(" ").take(old).collect::<String>(),
65 DEPTH.with(|slot| slot.set(old));
70 pub fn indent<R, F>(op: F) -> R where
74 // Use in conjunction with the log post-processor like `src/etc/indenter`
75 // to make debug output more readable.
78 debug!("<< (Result = {:?})", r);
83 _cannot_construct_outside_of_this_module: ()
86 impl Drop for Indenter {
87 fn drop(&mut self) { debug!("<<"); }
90 pub fn indenter() -> Indenter {
92 Indenter { _cannot_construct_outside_of_this_module: () }
95 struct LoopQueryVisitor<P> where P: FnMut(&ast::Expr_) -> bool {
100 impl<'v, P> Visitor<'v> for LoopQueryVisitor<P> where P: FnMut(&ast::Expr_) -> bool {
101 fn visit_expr(&mut self, e: &ast::Expr) {
102 self.flag |= (self.p)(&e.node);
104 // Skip inner loops, since a break in the inner loop isn't a
105 // break inside the outer loop
106 ast::ExprLoop(..) | ast::ExprWhile(..) => {}
107 _ => visit::walk_expr(self, e)
112 // Takes a predicate p, returns true iff p is true for any subexpressions
113 // of b -- skipping any inner loops (loop, while, loop_body)
114 pub fn loop_query<P>(b: &ast::Block, p: P) -> bool where P: FnMut(&ast::Expr_) -> bool {
115 let mut v = LoopQueryVisitor {
119 visit::walk_block(&mut v, b);
123 struct BlockQueryVisitor<P> where P: FnMut(&ast::Expr) -> bool {
128 impl<'v, P> Visitor<'v> for BlockQueryVisitor<P> where P: FnMut(&ast::Expr) -> bool {
129 fn visit_expr(&mut self, e: &ast::Expr) {
130 self.flag |= (self.p)(e);
131 visit::walk_expr(self, e)
135 // Takes a predicate p, returns true iff p is true for any subexpressions
136 // of b -- skipping any inner loops (loop, while, loop_body)
137 pub fn block_query<P>(b: &ast::Block, p: P) -> bool where P: FnMut(&ast::Expr) -> bool {
138 let mut v = BlockQueryVisitor {
142 visit::walk_block(&mut v, &*b);
146 /// K: Eq + Hash<S>, V, S, H: Hasher<S>
148 /// Determines whether there exists a path from `source` to `destination`. The
149 /// graph is defined by the `edges_map`, which maps from a node `S` to a list of
150 /// its adjacent nodes `T`.
152 /// Efficiency note: This is implemented in an inefficient way because it is
153 /// typically invoked on very small graphs. If the graphs become larger, a more
154 /// efficient graph representation and algorithm would probably be advised.
155 pub fn can_reach<T, S>(edges_map: &HashMap<T, Vec<T>, S>, source: T,
156 destination: T) -> bool
157 where S: HashState, T: Hash + Eq + Clone,
159 if source == destination {
163 // Do a little breadth-first-search here. The `queue` list
164 // doubles as a way to detect if we've seen a particular FR
165 // before. Note that we expect this graph to be an *extremely
167 let mut queue = vec!(source);
169 while i < queue.len() {
170 match edges_map.get(&queue[i]) {
172 for target in edges {
173 if *target == destination {
177 if !queue.iter().any(|x| x == target) {
178 queue.push((*target).clone());
189 /// Memoizes a one-argument closure using the given RefCell containing
190 /// a type implementing MutableMap to serve as a cache.
192 /// In the future the signature of this function is expected to be:
194 /// pub fn memoized<T: Clone, U: Clone, M: MutableMap<T, U>>(
195 /// cache: &RefCell<M>,
197 /// ) -> impl |T| -> U {
199 /// but currently it is not possible.
204 /// cache: RefCell<HashMap<usize, usize>>
207 /// fn factorial(ctxt: &Context, n: usize) -> usize {
208 /// memoized(&ctxt.cache, n, |n| match n {
210 /// _ => factorial(ctxt, n - 2) + factorial(ctxt, n - 1)
215 pub fn memoized<T, U, S, F>(cache: &RefCell<HashMap<T, U, S>>, arg: T, f: F) -> U
216 where T: Clone + Hash + Eq,
221 let key = arg.clone();
222 let result = cache.borrow().get(&key).cloned();
224 Some(result) => result,
227 cache.borrow_mut().insert(key, result.clone());
234 pub fn path2cstr(p: &Path) -> CString {
235 use std::os::unix::prelude::*;
237 let p: &OsStr = p.as_ref();
238 CString::new(p.as_bytes()).unwrap()
241 pub fn path2cstr(p: &Path) -> CString {
242 CString::new(p.to_str().unwrap()).unwrap()