Add E0612

Author: GuillaumeGomez

src/librustc_typeck/check/mod.rs

@@ -3053,26 +3053,20 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             let struct_path = self.tcx().item_path_str(did);
             struct_span_err!(self.tcx().sess, expr.span, E0611,
                              "field `{}` of tuple-struct `{}` is private",
-                             idx.node, struct_path);
+                             idx.node, struct_path).emit();
             return field_ty;
         }
 
-        self.type_error_message(
-            expr.span,
-            |actual| {
-                if tuple_like {
-                    format!("attempted out-of-bounds tuple index `{}` on \
-                                    type `{}`",
-                                   idx.node,
-                                   actual)
-                } else {
-                    format!("attempted tuple index `{}` on type `{}`, but the \
-                                     type was not a tuple or tuple struct",
-                                    idx.node,
-                                    actual)
-                }
-            },
-            expr_t);
+        if tuple_like {
+            type_error_struct!(self.tcx().sess, expr.span, expr_t, E0612,
+                               "attempted out-of-bounds tuple index `{}` on type `{}`",
+                               idx.node, expr_t).emit();
+        } else {
+            type_error_struct!(self.tcx().sess, expr.span, expr_t, E0613,
+                               "attempted tuple index `{}` on type `{}`, but the type was not a \
+                                tuple or tuple struct",
+                               idx.node, expr_t).emit();
+        }
 
         self.tcx().types.err
     }
@@ -3173,10 +3167,10 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 field_type_hint = tcx.types.err;
                 if let Some(_) = variant.find_field_named(field.name.node) {
                     let mut err = struct_span_err!(self.tcx.sess,
-                                                field.name.span,
-                                                E0062,
-                                                "field `{}` specified more than once",
-                                                field.name.node);
+                                                   field.name.span,
+                                                   E0062,
+                                                   "field `{}` specified more than once",
+                                                   field.name.node);
 
                     err.span_label(field.name.span, "used more than once");
 

src/librustc_typeck/diagnostics.rs

@@ -4208,6 +4208,40 @@ println!("{}", y.get()); // So we can get the value through the function.
 ```
 "##,
 
+E0612: r##"
+Attempted out-of-bounds tuple index.
+
+Erroneous code example:
+
+```compile_fail,E0612
+struct Foo(u32);
+
+let y = Foo(0);
+println!("{}", y.1); // error: attempted out-of-bounds tuple index `1`
+                     //        on type `Foo`
+```
+
+If a tuple/tuple-struct type has n fields, you can only try to access these n
+fields from 0 to (n - 1). So in this case, you can only index `0`. Example:
+
+```
+struct Foo(u32);
+
+let y = Foo(0);
+println!("{}", y.0); // ok!
+```
+"##,
+
+E0613: r##"
+Attempted tuple index on a type which isn't a tuple nor a tuple-struct.
+
+Erroneous code example:
+
+```compile_fail,E0613
+
+```
+"##,
+
 E0617: r##"
 Attempted to pass an invalid type of variable into a variadic function.
 

src/test/compile-fail/E0612.rs

@@ -0,0 +1,16 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+struct Foo(u32);
+
+fn main() {
+   let y = Foo(0);
+   y.1; //~ ERROR E0612
+}

src/test/compile-fail/struct-field-privacy.rs

@@ -42,7 +42,7 @@ fn test(a: A, b: inner::A, c: inner::B, d: xc::A, e: xc::B, z: inner::Z) {
     e.b; //~ ERROR: field `b` of struct `xc::B` is private
 
     z.0;
-    z.1; //~ ERROR: field `1` of struct `inner::Z` is private
+    z.1; //~ ERROR: field `1` of tuple-struct `inner::Z` is private
 }
 
 fn main() {}

src/test/ui/macros/macro-backtrace-invalid-internals.stderr

@@ -16,7 +16,7 @@ error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
 51 |     fake_field_stmt!();
    |     ------------------- in this macro invocation
 
-error: attempted tuple index `0` on type `{integer}`, but the type was not a tuple or tuple struct
+error[E0613]: attempted tuple index `0` on type `{integer}`, but the type was not a tuple or tuple struct
   --> $DIR/macro-backtrace-invalid-internals.rs:27:11
    |
 27 |           (1).0
@@ -43,7 +43,7 @@ error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
 55 |     let _ = fake_field_expr!();
    |             ------------------ in this macro invocation
 
-error: attempted tuple index `0` on type `{integer}`, but the type was not a tuple or tuple struct
+error[E0613]: attempted tuple index `0` on type `{integer}`, but the type was not a tuple or tuple struct
   --> $DIR/macro-backtrace-invalid-internals.rs:45:11
    |
 45 |           (1).0