vendor/syn/tests/common/parse.rs

   1 extern crate rustc_parse as parse;
   2 extern crate syntax;
   3 extern crate syntax_expand;
   4 extern crate syntax_pos;
   5
   6 use syntax::ast;
   7 use syntax::ptr::P;
   8 use syntax::sess::ParseSess;
   9 use syntax::source_map::FilePathMapping;
  10 use syntax_pos::FileName;
  11
  12 use std::panic;
  13
  14 pub fn libsyntax_expr(input: &str) -> Option<P<ast::Expr>> {
  15     match panic::catch_unwind(|| {
  16         let sess = ParseSess::new(FilePathMapping::empty());
  17         sess.span_diagnostic.set_continue_after_error(false);
  18         let e = parse::new_parser_from_source_str(
  19             &sess,
  20             FileName::Custom("test_precedence".to_string()),
  21             input.to_string(),
  22         )
  23         .parse_expr();
  24         match e {
  25             Ok(expr) => Some(expr),
  26             Err(mut diagnostic) => {
  27                 diagnostic.emit();
  28                 None
  29             }
  30         }
  31     }) {
  32         Ok(Some(e)) => Some(e),
  33         Ok(None) => None,
  34         Err(_) => {
  35             errorf!("libsyntax panicked\n");
  36             None
  37         }
  38     }
  39 }
  40
  41 pub fn syn_expr(input: &str) -> Option<syn::Expr> {
  42     match syn::parse_str(input) {
  43         Ok(e) => Some(e),
  44         Err(msg) => {
  45             errorf!("syn failed to parse\n{:?}\n", msg);
  46             None
  47         }
  48     }
  49 }