Add some more tracing

compiler/rustc_errors/src/lib.rs

@@ -13,9 +13,11 @@
 #[macro_use]
 extern crate rustc_macros;
 
+#[macro_use]
+extern crate tracing;
+
 pub use emitter::ColorConfig;
 
-use tracing::debug;
 use Level::*;
 
 use emitter::{is_case_difference, Emitter, EmitterWriter};

compiler/rustc_parse/src/lib.rs

@@ -6,6 +6,9 @@
 #![feature(box_patterns)]
 #![recursion_limit = "256"]
 
+#[macro_use]
+extern crate tracing;
+
 use rustc_ast as ast;
 use rustc_ast::token::{self, Nonterminal, Token, TokenKind};
 use rustc_ast::tokenstream::{self, AttributesData, CanSynthesizeMissingTokens, LazyTokenStream};

compiler/rustc_parse/src/parser/expr.rs

@@ -1084,6 +1084,7 @@ fn parse_fn_call_expr(&mut self, lo: Span, fun: P<Expr>) -> P<Expr> {
 
     /// If we encounter a parser state that looks like the user has written a `struct` literal with
     /// parentheses instead of braces, recover the parser state and provide suggestions.
+    #[instrument(skip(self, seq, snapshot), level = "trace")]
     fn maybe_recover_struct_lit_bad_delims(
         &mut self,
         lo: Span,

compiler/rustc_span/src/lib.rs

@@ -25,6 +25,9 @@
 #[macro_use]
 extern crate rustc_macros;
 
+#[macro_use]
+extern crate tracing;
+
 use rustc_data_structures::AtomicRef;
 use rustc_macros::HashStable_Generic;
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};

compiler/rustc_span/src/source_map.rs

@@ -474,11 +474,12 @@ pub fn is_multiline(&self, sp: Span) -> bool {
         f.lookup_line(sp.lo()) != f.lookup_line(sp.hi())
     }
 
+    #[instrument(skip(self), level = "trace")]
     pub fn is_valid_span(&self, sp: Span) -> Result<(Loc, Loc), SpanLinesError> {
         let lo = self.lookup_char_pos(sp.lo());
-        debug!("span_to_lines: lo={:?}", lo);
+        trace!(?lo);
         let hi = self.lookup_char_pos(sp.hi());
-        debug!("span_to_lines: hi={:?}", hi);
+        trace!(?hi);
         if lo.file.start_pos != hi.file.start_pos {
             return Err(SpanLinesError::DistinctSources(DistinctSources {
                 begin: (lo.file.name.clone(), lo.file.start_pos),