src/tools/compiletest/src/json.rs

   1 //! These structs are a subset of the ones found in `syntax::json`.
   2 //! They are only used for deserialization of JSON output provided by libtest.
   3
   4 use crate::errors::{Error, ErrorKind};
   5 use crate::runtest::ProcRes;
   6 use serde_json;
   7 use std::path::Path;
   8 use std::str::FromStr;
   9
  10 #[derive(Deserialize)]
  11 struct Diagnostic {
  12     message: String,
  13     code: Option<DiagnosticCode>,
  14     level: String,
  15     spans: Vec<DiagnosticSpan>,
  16     children: Vec<Diagnostic>,
  17     rendered: Option<String>,
  18 }
  19
  20 #[derive(Deserialize, Clone)]
  21 struct DiagnosticSpan {
  22     file_name: String,
  23     line_start: usize,
  24     line_end: usize,
  25     column_start: usize,
  26     column_end: usize,
  27     is_primary: bool,
  28     label: Option<String>,
  29     suggested_replacement: Option<String>,
  30     expansion: Option<Box<DiagnosticSpanMacroExpansion>>,
  31 }
  32
  33 impl DiagnosticSpan {
  34     /// Returns the deepest source span in the macro call stack with a given file name.
  35     /// This is either the supplied span, or the span for some macro callsite that expanded to it.
  36     fn first_callsite_in_file(&self, file_name: &str) -> &DiagnosticSpan {
  37         if self.file_name == file_name {
  38             self
  39         } else {
  40             self.expansion
  41                 .as_ref()
  42                 .map(|origin| origin.span.first_callsite_in_file(file_name))
  43                 .unwrap_or(self)
  44         }
  45     }
  46 }
  47
  48 #[derive(Deserialize, Clone)]
  49 struct DiagnosticSpanMacroExpansion {
  50     /// span where macro was applied to generate this code
  51     span: DiagnosticSpan,
  52
  53     /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]")
  54     macro_decl_name: String,
  55 }
  56
  57 #[derive(Deserialize, Clone)]
  58 struct DiagnosticCode {
  59     /// The code itself.
  60     code: String,
  61     /// An explanation for the code.
  62     explanation: Option<String>,
  63 }
  64
  65 pub fn extract_rendered(output: &str, proc_res: &ProcRes) -> String {
  66     output
  67         .lines()
  68         .filter_map(|line| {
  69             if line.starts_with('{') {
  70                 match serde_json::from_str::<Diagnostic>(line) {
  71                     Ok(diagnostic) => diagnostic.rendered,
  72                     Err(error) => {
  73                         proc_res.fatal(Some(&format!(
  74                             "failed to decode compiler output as json: \
  75                              `{}`\nline: {}\noutput: {}",
  76                             error, line, output
  77                         )));
  78                     }
  79                 }
  80             } else {
  81                 None
  82             }
  83         })
  84         .collect()
  85 }
  86
  87 pub fn parse_output(file_name: &str, output: &str, proc_res: &ProcRes) -> Vec<Error> {
  88     output
  89         .lines()
  90         .flat_map(|line| parse_line(file_name, line, output, proc_res))
  91         .collect()
  92 }
  93
  94 fn parse_line(file_name: &str, line: &str, output: &str, proc_res: &ProcRes) -> Vec<Error> {
  95     // The compiler sometimes intermingles non-JSON stuff into the
  96     // output.  This hack just skips over such lines. Yuck.
  97     if line.starts_with('{') {
  98         match serde_json::from_str::<Diagnostic>(line) {
  99             Ok(diagnostic) => {
 100                 let mut expected_errors = vec![];
 101                 push_expected_errors(&mut expected_errors, &diagnostic, &[], file_name);
 102                 expected_errors
 103             }
 104             Err(error) => {
 105                 proc_res.fatal(Some(&format!(
 106                     "failed to decode compiler output as json: \
 107                      `{}`\nline: {}\noutput: {}",
 108                     error, line, output
 109                 )));
 110             }
 111         }
 112     } else {
 113         vec![]
 114     }
 115 }
 116
 117 fn push_expected_errors(
 118     expected_errors: &mut Vec<Error>,
 119     diagnostic: &Diagnostic,
 120     default_spans: &[&DiagnosticSpan],
 121     file_name: &str,
 122 ) {
 123     // In case of macro expansions, we need to get the span of the callsite
 124     let spans_info_in_this_file: Vec<_> = diagnostic
 125         .spans
 126         .iter()
 127         .map(|span| (span.is_primary, span.first_callsite_in_file(file_name)))
 128         .filter(|(_, span)| Path::new(&span.file_name) == Path::new(&file_name))
 129         .collect();
 130
 131     let spans_in_this_file: Vec<_> = spans_info_in_this_file.iter()
 132         .map(|(_, span)| span)
 133         .collect();
 134
 135     let primary_spans: Vec<_> = spans_info_in_this_file.iter()
 136         .filter(|(is_primary, _)| *is_primary)
 137         .map(|(_, span)| span)
 138         .take(1) // sometimes we have more than one showing up in the json; pick first
 139         .cloned()
 140         .collect();
 141     let primary_spans = if primary_spans.is_empty() {
 142         // subdiagnostics often don't have a span of their own;
 143         // inherit the span from the parent in that case
 144         default_spans
 145     } else {
 146         &primary_spans
 147     };
 148
 149     // We break the output into multiple lines, and then append the
 150     // [E123] to every line in the output. This may be overkill.  The
 151     // intention was to match existing tests that do things like "//|
 152     // found `i32` [E123]" and expect to match that somewhere, and yet
 153     // also ensure that `//~ ERROR E123` *always* works. The
 154     // assumption is that these multi-line error messages are on their
 155     // way out anyhow.
 156     let with_code = |span: &DiagnosticSpan, text: &str| {
 157         match diagnostic.code {
 158             Some(ref code) =>
 159                 // FIXME(#33000) -- it'd be better to use a dedicated
 160                 // UI harness than to include the line/col number like
 161                 // this, but some current tests rely on it.
 162                 //
 163                 // Note: Do NOT include the filename. These can easily
 164                 // cause false matches where the expected message
 165                 // appears in the filename, and hence the message
 166                 // changes but the test still passes.
 167                 format!("{}:{}: {}:{}: {} [{}]",
 168                         span.line_start, span.column_start,
 169                         span.line_end, span.column_end,
 170                         text, code.code.clone()),
 171             None =>
 172                 // FIXME(#33000) -- it'd be better to use a dedicated UI harness
 173                 format!("{}:{}: {}:{}: {}",
 174                         span.line_start, span.column_start,
 175                         span.line_end, span.column_end,
 176                         text),
 177         }
 178     };
 179
 180     // Convert multi-line messages into multiple expected
 181     // errors. We expect to replace these with something
 182     // more structured shortly anyhow.
 183     let mut message_lines = diagnostic.message.lines();
 184     if let Some(first_line) = message_lines.next() {
 185         for span in primary_spans {
 186             let msg = with_code(span, first_line);
 187             let kind = ErrorKind::from_str(&diagnostic.level).ok();
 188             expected_errors.push(Error {
 189                 line_num: span.line_start,
 190                 kind,
 191                 msg,
 192             });
 193         }
 194     }
 195     for next_line in message_lines {
 196         for span in primary_spans {
 197             expected_errors.push(Error {
 198                 line_num: span.line_start,
 199                 kind: None,
 200                 msg: with_code(span, next_line),
 201             });
 202         }
 203     }
 204
 205     // If the message has a suggestion, register that.
 206     for span in primary_spans {
 207         if let Some(ref suggested_replacement) = span.suggested_replacement {
 208             for (index, line) in suggested_replacement.lines().enumerate() {
 209                 expected_errors.push(Error {
 210                     line_num: span.line_start + index,
 211                     kind: Some(ErrorKind::Suggestion),
 212                     msg: line.to_string(),
 213                 });
 214             }
 215         }
 216     }
 217
 218     // Add notes for the backtrace
 219     for span in primary_spans {
 220         for frame in &span.expansion {
 221             push_backtrace(expected_errors, frame, file_name);
 222         }
 223     }
 224
 225     // Add notes for any labels that appear in the message.
 226     for span in spans_in_this_file
 227         .iter()
 228         .filter(|span| span.label.is_some())
 229     {
 230         expected_errors.push(Error {
 231             line_num: span.line_start,
 232             kind: Some(ErrorKind::Note),
 233             msg: span.label.clone().unwrap(),
 234         });
 235     }
 236
 237     // Flatten out the children.
 238     for child in &diagnostic.children {
 239         push_expected_errors(expected_errors, child, primary_spans, file_name);
 240     }
 241 }
 242
 243 fn push_backtrace(
 244     expected_errors: &mut Vec<Error>,
 245     expansion: &DiagnosticSpanMacroExpansion,
 246     file_name: &str,
 247 ) {
 248     if Path::new(&expansion.span.file_name) == Path::new(&file_name) {
 249         expected_errors.push(Error {
 250             line_num: expansion.span.line_start,
 251             kind: Some(ErrorKind::Note),
 252             msg: format!("in this expansion of {}", expansion.macro_decl_name),
 253         });
 254     }
 255
 256     for previous_expansion in &expansion.span.expansion {
 257         push_backtrace(expected_errors, previous_expansion, file_name);
 258     }
 259 }