src/tools/compiletest/src/json.rs

   1 // Copyright 2012-2015 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 use errors::{Error, ErrorKind};
  12 use rustc_serialize::json;
  13 use std::str::FromStr;
  14 use std::path::Path;
  15 use runtest::ProcRes;
  16
  17 // These structs are a subset of the ones found in
  18 // `syntax::json`.
  19
  20 #[derive(RustcEncodable, RustcDecodable)]
  21 struct Diagnostic {
  22     message: String,
  23     code: Option<DiagnosticCode>,
  24     level: String,
  25     spans: Vec<DiagnosticSpan>,
  26     children: Vec<Diagnostic>,
  27     rendered: Option<String>,
  28 }
  29
  30 #[derive(RustcEncodable, RustcDecodable, Clone)]
  31 struct DiagnosticSpan {
  32     file_name: String,
  33     line_start: usize,
  34     line_end: usize,
  35     column_start: usize,
  36     column_end: usize,
  37     is_primary: bool,
  38     label: Option<String>,
  39     suggested_replacement: Option<String>,
  40     expansion: Option<Box<DiagnosticSpanMacroExpansion>>,
  41 }
  42
  43 #[derive(RustcEncodable, RustcDecodable, Clone)]
  44 struct DiagnosticSpanMacroExpansion {
  45     /// span where macro was applied to generate this code
  46     span: DiagnosticSpan,
  47
  48     /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]")
  49     macro_decl_name: String,
  50 }
  51
  52 #[derive(RustcEncodable, RustcDecodable, Clone)]
  53 struct DiagnosticCode {
  54     /// The code itself.
  55     code: String,
  56     /// An explanation for the code.
  57     explanation: Option<String>,
  58 }
  59
  60 pub fn parse_output(file_name: &str, output: &str, proc_res: &ProcRes) -> Vec<Error> {
  61     output.lines()
  62         .flat_map(|line| parse_line(file_name, line, output, proc_res))
  63         .collect()
  64 }
  65
  66 fn parse_line(file_name: &str, line: &str, output: &str, proc_res: &ProcRes) -> Vec<Error> {
  67     // The compiler sometimes intermingles non-JSON stuff into the
  68     // output.  This hack just skips over such lines. Yuck.
  69     if line.starts_with('{') {
  70         match json::decode::<Diagnostic>(line) {
  71             Ok(diagnostic) => {
  72                 let mut expected_errors = vec![];
  73                 push_expected_errors(&mut expected_errors, &diagnostic, &[], file_name);
  74                 expected_errors
  75             }
  76             Err(error) => {
  77                 proc_res.fatal(Some(&format!("failed to decode compiler output as json: \
  78                                               `{}`\noutput: {}\nline: {}",
  79                                              error,
  80                                              line,
  81                                              output)));
  82             }
  83         }
  84     } else {
  85         vec![]
  86     }
  87 }
  88
  89 fn push_expected_errors(expected_errors: &mut Vec<Error>,
  90                         diagnostic: &Diagnostic,
  91                         default_spans: &[&DiagnosticSpan],
  92                         file_name: &str) {
  93     let spans_in_this_file: Vec<_> = diagnostic.spans
  94         .iter()
  95         .filter(|span| Path::new(&span.file_name) == Path::new(&file_name))
  96         .collect();
  97
  98     let primary_spans: Vec<_> = spans_in_this_file.iter()
  99         .cloned()
 100         .filter(|span| span.is_primary)
 101         .take(1) // sometimes we have more than one showing up in the json; pick first
 102         .collect();
 103     let primary_spans = if primary_spans.is_empty() {
 104         // subdiagnostics often don't have a span of their own;
 105         // inherit the span from the parent in that case
 106         default_spans
 107     } else {
 108         &primary_spans
 109     };
 110
 111     // We break the output into multiple lines, and then append the
 112     // [E123] to every line in the output. This may be overkill.  The
 113     // intention was to match existing tests that do things like "//|
 114     // found `i32` [E123]" and expect to match that somewhere, and yet
 115     // also ensure that `//~ ERROR E123` *always* works. The
 116     // assumption is that these multi-line error messages are on their
 117     // way out anyhow.
 118     let with_code = |span: &DiagnosticSpan, text: &str| {
 119         match diagnostic.code {
 120             Some(ref code) =>
 121                 // FIXME(#33000) -- it'd be better to use a dedicated
 122                 // UI harness than to include the line/col number like
 123                 // this, but some current tests rely on it.
 124                 //
 125                 // Note: Do NOT include the filename. These can easily
 126                 // cause false matches where the expected message
 127                 // appears in the filename, and hence the message
 128                 // changes but the test still passes.
 129                 format!("{}:{}: {}:{}: {} [{}]",
 130                         span.line_start, span.column_start,
 131                         span.line_end, span.column_end,
 132                         text, code.code.clone()),
 133             None =>
 134                 // FIXME(#33000) -- it'd be better to use a dedicated UI harness
 135                 format!("{}:{}: {}:{}: {}",
 136                         span.line_start, span.column_start,
 137                         span.line_end, span.column_end,
 138                         text),
 139         }
 140     };
 141
 142     // Convert multi-line messages into multiple expected
 143     // errors. We expect to replace these with something
 144     // more structured shortly anyhow.
 145     let mut message_lines = diagnostic.message.lines();
 146     if let Some(first_line) = message_lines.next() {
 147         for span in primary_spans {
 148             let msg = with_code(span, first_line);
 149             let kind = ErrorKind::from_str(&diagnostic.level).ok();
 150             expected_errors.push(Error {
 151                 line_num: span.line_start,
 152                 kind,
 153                 msg,
 154             });
 155         }
 156     }
 157     for next_line in message_lines {
 158         for span in primary_spans {
 159             expected_errors.push(Error {
 160                 line_num: span.line_start,
 161                 kind: None,
 162                 msg: with_code(span, next_line),
 163             });
 164         }
 165     }
 166
 167     // If the message has a suggestion, register that.
 168     for span in primary_spans {
 169         if let Some(ref suggested_replacement) = span.suggested_replacement {
 170             for (index, line) in suggested_replacement.lines().enumerate() {
 171                 expected_errors.push(Error {
 172                     line_num: span.line_start + index,
 173                     kind: Some(ErrorKind::Suggestion),
 174                     msg: line.to_string(),
 175                 });
 176             }
 177         }
 178     }
 179
 180     // Add notes for the backtrace
 181     for span in primary_spans {
 182         for frame in &span.expansion {
 183             push_backtrace(expected_errors, frame, file_name);
 184         }
 185     }
 186
 187     // Add notes for any labels that appear in the message.
 188     for span in spans_in_this_file.iter()
 189         .filter(|span| span.label.is_some()) {
 190         expected_errors.push(Error {
 191             line_num: span.line_start,
 192             kind: Some(ErrorKind::Note),
 193             msg: span.label.clone().unwrap(),
 194         });
 195     }
 196
 197     // Flatten out the children.
 198     for child in &diagnostic.children {
 199         push_expected_errors(expected_errors, child, primary_spans, file_name);
 200     }
 201 }
 202
 203 fn push_backtrace(expected_errors: &mut Vec<Error>,
 204                   expansion: &DiagnosticSpanMacroExpansion,
 205                   file_name: &str) {
 206     if Path::new(&expansion.span.file_name) == Path::new(&file_name) {
 207         expected_errors.push(Error {
 208             line_num: expansion.span.line_start,
 209             kind: Some(ErrorKind::Note),
 210             msg: format!("in this expansion of {}", expansion.macro_decl_name),
 211         });
 212     }
 213
 214     for previous_expansion in &expansion.span.expansion {
 215         push_backtrace(expected_errors, previous_expansion, file_name);
 216     }
 217 }