port compiletest to use JSON output

This uncovered a lot of bugs in compiletest and also some shortcomings
of our existing JSON output. We had to add information to the JSON
output, such as suggested text and macro backtraces. We also had to fix
various bugs in the existing tests.

Joint work with jntrnr.

1 files changed, 9 insertions, 38 deletions

diff --git a/src/libsyntax/errors/emitter.rs b/src/libsyntax/errors/emitter.rs
index 61fdc8453d8..0b5234769b2 100644
--- a/src/libsyntax/errors/emitter.rs
+++ b/src/libsyntax/errors/emitter.rs
@@ -577,46 +577,17 @@ impl EmitterWriter {
     fn print_macro_backtrace(&mut self,
                              sp: Span)
                              -> io::Result<()> {
-        let mut last_span = codemap::DUMMY_SP;
-        let mut span = sp;
-
-        loop {
-            let span_name_span = self.cm.with_expn_info(span.expn_id, |expn_info| {
-                expn_info.map(|ei| {
-                    let (pre, post) = match ei.callee.format {
-                        codemap::MacroAttribute(..) => ("#[", "]"),
-                        codemap::MacroBang(..) => ("", "!"),
-                    };
-                    let macro_decl_name = format!("in this expansion of {}{}{}",
-                                                  pre,
-                                                  ei.callee.name(),
-                                                  post);
-                    let def_site_span = ei.callee.span;
-                    (ei.call_site, macro_decl_name, def_site_span)
-                })
-            });
-            let (macro_decl_name, def_site_span) = match span_name_span {
-                None => break,
-                Some((sp, macro_decl_name, def_site_span)) => {
-                    span = sp;
-                    (macro_decl_name, def_site_span)
-                }
-            };
-
-            // Don't print recursive invocations
-            if !span.source_equal(&last_span) {
-                let mut diag_string = macro_decl_name;
-                if let Some(def_site_span) = def_site_span {
-                    diag_string.push_str(&format!(" (defined in {})",
-                                                  self.cm.span_to_filename(def_site_span)));
-                }
-
-                let snippet = self.cm.span_to_string(span);
-                print_diagnostic(&mut self.dst, &snippet, Note, &diag_string, None)?;
+        for trace in self.cm.macro_backtrace(sp) {
+            let mut diag_string =
+                format!("in this expansion of {}", trace.macro_decl_name);
+            if let Some(def_site_span) = trace.def_site_span {
+                diag_string.push_str(
+                    &format!(" (defined in {})",
+                        self.cm.span_to_filename(def_site_span)));
             }
-            last_span = span;
+            let snippet = self.cm.span_to_string(sp);
+            print_diagnostic(&mut self.dst, &snippet, Note, &diag_string, None)?;
         }
-
         Ok(())
     }
 }