rust/src/libsyntax/diagnostics/metadata.rs
Jorge Aparicio 0f02309e4b try! -> ?
Automated conversion using the untry tool [1] and the following command:

```
$ find -name '*.rs' -type f | xargs untry
```

at the root of the Rust repo.

[1]: https://github.com/japaric/untry
2016-03-22 22:01:37 -05:00

102 lines
3.5 KiB
Rust

// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! This module contains utilities for outputting metadata for diagnostic errors.
//!
//! Each set of errors is mapped to a metadata file by a name, which is
//! currently always a crate name.
use std::collections::BTreeMap;
use std::path::PathBuf;
use std::fs::{remove_file, create_dir_all, File};
use std::io::Write;
use std::error::Error;
use rustc_serialize::json::as_json;
use codemap::Span;
use ext::base::ExtCtxt;
use diagnostics::plugin::{ErrorMap, ErrorInfo};
// Default metadata directory to use for extended error JSON.
const ERROR_METADATA_PREFIX: &'static str = "tmp/extended-errors";
/// JSON encodable/decodable version of `ErrorInfo`.
#[derive(PartialEq, RustcDecodable, RustcEncodable)]
pub struct ErrorMetadata {
pub description: Option<String>,
pub use_site: Option<ErrorLocation>
}
/// Mapping from error codes to metadata that can be (de)serialized.
pub type ErrorMetadataMap = BTreeMap<String, ErrorMetadata>;
/// JSON encodable error location type with filename and line number.
#[derive(PartialEq, RustcDecodable, RustcEncodable)]
pub struct ErrorLocation {
pub filename: String,
pub line: usize
}
impl ErrorLocation {
/// Create an error location from a span.
pub fn from_span(ecx: &ExtCtxt, sp: Span) -> ErrorLocation {
let loc = ecx.codemap().lookup_char_pos_adj(sp.lo);
ErrorLocation {
filename: loc.filename,
line: loc.line
}
}
}
/// Get the directory where metadata for a given `prefix` should be stored.
///
/// See `output_metadata`.
pub fn get_metadata_dir(prefix: &str) -> PathBuf {
PathBuf::from(ERROR_METADATA_PREFIX).join(prefix)
}
/// Map `name` to a path in the given directory: <directory>/<name>.json
fn get_metadata_path(directory: PathBuf, name: &str) -> PathBuf {
directory.join(format!("{}.json", name))
}
/// Write metadata for the errors in `err_map` to disk, to a file corresponding to `prefix/name`.
///
/// For our current purposes the prefix is the target architecture and the name is a crate name.
/// If an error occurs steps will be taken to ensure that no file is created.
pub fn output_metadata(ecx: &ExtCtxt, prefix: &str, name: &str, err_map: &ErrorMap)
-> Result<(), Box<Error>>
{
// Create the directory to place the file in.
let metadata_dir = get_metadata_dir(prefix);
create_dir_all(&metadata_dir)?;
// Open the metadata file.
let metadata_path = get_metadata_path(metadata_dir, name);
let mut metadata_file = File::create(&metadata_path)?;
// Construct a serializable map.
let json_map = err_map.iter().map(|(k, &ErrorInfo { description, use_site })| {
let key = k.as_str().to_string();
let value = ErrorMetadata {
description: description.map(|n| n.as_str().to_string()),
use_site: use_site.map(|sp| ErrorLocation::from_span(ecx, sp))
};
(key, value)
}).collect::<ErrorMetadataMap>();
// Write the data to the file, deleting it if the write fails.
let result = write!(&mut metadata_file, "{}", as_json(&json_map));
if result.is_err() {
remove_file(&metadata_path)?;
}
Ok(result?)
}