Update reference.

Author: xiongmao86

tests/ui/collapsible_span_lint_calls.fixed

@@ -0,0 +1,52 @@
+// run-rustfix
+#![deny(clippy::internal)]
+#![feature(rustc_private)]
+
+extern crate rustc_session;
+extern crate rustc_errors;
+extern crate rustc_lint;
+extern crate syntax;
+extern crate rustc_span;
+
+use rustc_session::{declare_tool_lint, declare_lint_pass};
+use rustc_errors::{DiagnosticBuilder, Applicability};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext, Lint};
+use syntax::ast::Expr;
+use rustc_span::source_map::Span;
+
+#[allow(unused_variables)]
+pub fn span_lint_and_then<'a, T: LintContext, F>(cx: &'a T, lint: &'static Lint, sp: Span, msg: &str, f: F)
+where
+    F: for<'b> FnOnce(&mut DiagnosticBuilder<'b>),
+{
+}
+
+declare_tool_lint!{
+    pub clippy::TEST_LINT,
+    Warn,
+    "",
+    report_in_external_macro: true
+}
+
+declare_lint_pass!(Pass => [TEST_LINT]);
+
+impl EarlyLintPass for Pass {
+    fn check_expr(&mut self, cx: &EarlyContext, expr: &Expr)  {
+        let lint_msg = "lint message";
+        let help_msg = "help message";
+        let note_msg = "note message";
+        let sugg = "new_call()";
+
+        span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db| {
+            db.span_suggestion(expr.span, help_msg, sugg.to_string(), Applicability::MachineApplicable);
+        });
+        span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db| {
+            db.span_help(expr.span, help_msg);
+        });
+        span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db|
+            db.span_note(expr.span, note_msg)
+        );
+    }
+}
+
+fn main() {}

tests/ui/collapsible_span_lint_calls.stderr

@@ -0,0 +1,17 @@
+error[E0308]: mismatched types
+  --> $DIR/collapsible_span_lint_calls.rs:44:13
+   |
+LL |             db.span_help(expr.span, help_msg)
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^- help: try adding a semicolon: `;`
+   |             |
+   |             expected `()`, found `&mut rustc_errors::DiagnosticBuilder<'_>`
+
+error[E0308]: mismatched types
+  --> $DIR/collapsible_span_lint_calls.rs:47:13
+   |
+LL |             db.span_note(expr.span, note_msg)
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found `&mut rustc_errors::DiagnosticBuilder<'_>`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.