src/librustc/middle/recursion_limit.rs

   1 // Copyright 2012 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.
   4 //
   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.
  10
  11 // Recursion limit.
  12 //
  13 // There are various parts of the compiler that must impose arbitrary limits
  14 // on how deeply they recurse to prevent stack overflow. Users can override
  15 // this via an attribute on the crate like `#![recursion_limit="22"]`. This pass
  16 // just peeks and looks for that attribute.
  17
  18 use session::Session;
  19 use syntax::ast;
  20
  21 pub fn update_recursion_limit(sess: &Session, krate: &ast::Crate) {
  22     for attr in &krate.attrs {
  23         if !attr.check_name("recursion_limit") {
  24             continue;
  25         }
  26
  27         if let Some(s) = attr.value_str() {
  28             if let Some(n) = s.parse().ok() {
  29                 sess.recursion_limit.set(n);
  30                 return;
  31             }
  32         }
  33
  34         span_err!(sess, attr.span, E0296, "malformed recursion limit attribute, \
  35                                   expected #![recursion_limit=\"N\"]");
  36     }
  37 }