Auto merge of #34789 - jonathandturner:simplify_liberror, r=alexcrichton

Simplify librustc_errors

This is part 2 of the error crate refactor, starting with #34403.

In this refactor, I focused on slimming down the error crate to fewer moving parts.  As such, I've removed quite a few parts and replaced the with simpler, straight-line code.  Specifically, this PR:

* Removes BasicEmitter
* Remove emit from emitter, leaving emit_struct
* Renames emit_struct to emit
* Removes CoreEmitter and focuses on a single Emitter
* Implements the latest changes to error format RFC (#1644)
* Removes (now-unused) code in emitter.rs and snippet.rs
* Moves more tests to the UI tester, removing some duplicate tests in the process

There is probably more that could be done with some additional refactoring, but this felt like it was getting to a good state.

r? @alexcrichton   cc: @Manishearth (as there may be breaking changes in stuff I removed/changed)

2 files changed, 6 insertions, 2 deletions

diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 77b5c10899a..5ea1d6be9fe 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -1686,7 +1686,7 @@ mod tests {
         // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
         let emitter = errors::emitter::EmitterWriter::new(Box::new(io::sink()),
                                                 None,
-                                                cm,
+                                                Some(cm),
                                                 errors::snippet::FormatMode::EnvironmentSelected);
         errors::Handler::with_emitter(true, false, Box::new(emitter))
     }
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 9502bc48a3e..6af4d95e888 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -50,7 +50,11 @@ pub struct ParseSess {
 impl ParseSess {
     pub fn new() -> ParseSess {
         let cm = Rc::new(CodeMap::new());
-        let handler = Handler::with_tty_emitter(ColorConfig::Auto, None, true, false, cm.clone());
+        let handler = Handler::with_tty_emitter(ColorConfig::Auto,
+                                                None,
+                                                true,
+                                                false,
+                                                Some(cm.clone()));
         ParseSess::with_span_handler(handler, cm)
     }