Report lint names in json diagnostics

Author: oli-obk

src/librustc/lint/mod.rs

@@ -463,6 +463,8 @@ pub fn struct_lint_level<'a>(sess: &'a Session,
         }
     }
 
+    err.code(name);
+
     // Check for future incompatibility lints and issue a stronger warning.
     let lints = sess.lint_store.borrow();
     if let Some(future_incompatible) = lints.future_incompatible(LintId::of(lint)) {

src/librustc_errors/emitter.rs

@@ -906,7 +906,8 @@ impl EmitterWriter {
         } else {
             buffer.append(0, &level.to_string(), Style::Level(level.clone()));
             match code {
-                &Some(ref code) => {
+                // only render error codes, not lint codes
+                &Some(ref code) if code.starts_with("E") && code.len() == 5 => {
                     buffer.append(0, "[", Style::Level(level.clone()));
                     buffer.append(0, &code, Style::Level(level.clone()));
                     buffer.append(0, "]", Style::Level(level.clone()));

src/test/ui/lint/unused_parens_json_suggestion.stderr

@@ -1 +1 @@
-{"message":"unnecessary parentheses around assigned value","code":null,"level":"warning","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":1001,"byte_end":1014,"line_start":24,"line_end":24,"column_start":14,"column_end":27,"is_primary":true,"text":[{"text":"    let _a = (1 / (2 + 3));","highlight_start":14,"highlight_end":27}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":847,"byte_end":860,"line_start":19,"line_end":19,"column_start":9,"column_end":22,"is_primary":true,"text":[{"text":"#![warn(unused_parens)]","highlight_start":9,"highlight_end":22}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":null},{"message":"remove these parentheses","code":null,"level":"help","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":1001,"byte_end":1014,"line_start":24,"line_end":24,"column_start":14,"column_end":27,"is_primary":true,"text":[{"text":"    let _a = (1 / (2 + 3));","highlight_start":14,"highlight_end":27}],"label":null,"suggested_replacement":"1 / (2 + 3)","expansion":null}],"children":[],"rendered":null}],"rendered":null}
+{"message":"unnecessary parentheses around assigned value","code":{"code":"unused_parens","explanation":null},"level":"warning","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":1001,"byte_end":1014,"line_start":24,"line_end":24,"column_start":14,"column_end":27,"is_primary":true,"text":[{"text":"    let _a = (1 / (2 + 3));","highlight_start":14,"highlight_end":27}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[{"message":"lint level defined here","code":null,"level":"note","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":847,"byte_end":860,"line_start":19,"line_end":19,"column_start":9,"column_end":22,"is_primary":true,"text":[{"text":"#![warn(unused_parens)]","highlight_start":9,"highlight_end":22}],"label":null,"suggested_replacement":null,"expansion":null}],"children":[],"rendered":null},{"message":"remove these parentheses","code":null,"level":"help","spans":[{"file_name":"$DIR/unused_parens_json_suggestion.rs","byte_start":1001,"byte_end":1014,"line_start":24,"line_end":24,"column_start":14,"column_end":27,"is_primary":true,"text":[{"text":"    let _a = (1 / (2 + 3));","highlight_start":14,"highlight_end":27}],"label":null,"suggested_replacement":"1 / (2 + 3)","expansion":null}],"children":[],"rendered":null}],"rendered":null}