suggests with whole macro call

src/libsyntax_ext/concat.rs

@@ -14,7 +14,6 @@ use syntax::ext::build::AstBuilder;
 use syntax::symbol::Symbol;
 use syntax_pos;
 use syntax::tokenstream;
-use syntax::print::pprust;
 
 use std::string::String;
 
@@ -55,15 +54,7 @@ pub fn expand_syntax_ext(cx: &mut base::ExtCtxt,
             }
             _ => {
                 let mut err = cx.struct_span_err(e.span, "expected a literal");
-                let msg = cx.codemap().span_to_snippet(e.span).unwrap_or_else(
-                    |_| pprust::expr_to_string(&e)
-                );
-                err.span_suggestion(
-                    e.span,
-                    "consider changing this to",
-                    format!("\"{{}}\", {}", msg)
-                );
-                err.span_note(
+                err.span_help(
                     e.span,
                     "you might be missing a string literal to format with",
                 );

src/test/ui/macros/bad_hello.stderr

@@ -2,7 +2,13 @@ error: expected a literal
   --> $DIR/bad_hello.rs:12:14
    |
 LL |     println!(3 + 4); //~ ERROR expected a literal
-   |              ^^^^^ help: consider changing this to: `"{}", 3 + 4`
+   |              ^^^^^
+   |
+help: you might be missing a string literal to format with
+  --> $DIR/bad_hello.rs:12:14
+   |
+LL |     println!(3 + 4); //~ ERROR expected a literal
+   |              ^^^^^
 
 error: aborting due to previous error