auto merge of #8739 : fhahn/rust/ticket_2275, r=brson

This is a pull request for #2275

I've created a small python script to generate test files for a list of keywords (as break do else enum extern false fn for if impl let loop match mod mut priv pub ref return self static struct super true trait type unsafe use while), but I'm not really sure where to put it. I've added the created files as well.

I did not use 

     fn main() {
        let $KW = "foo"; //~ error
        println($KW); //~ error
    } 

as template, because for return, self, ref, loop, mut and break this does not raise an error in the ```println``` line, only in the ```let``` line.

src/etc/generate-keyword-tests.py

+#!/usr/bin/env python
+# xfail-license
+# Copyright 2013 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.
+"""
+This script takes a list of keywords and generates a testcase, that checks
+if using the keyword as identifier fails, for every keyword. The generate
+test files are set read-only.
+Test for https://github.com/mozilla/rust/issues/2275
+
+sample usage: src/etc/generate-keyword-tests.py as break
+"""
+
+import sys
+import os
+import datetime
+import stat
+
+
+template = """// Copyright %d 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py %s'
+
+fn main() {
+    let %s = "foo"; //~ error: ident
+}
+"""
+
+test_dir = os.path.abspath(
+    os.path.join(os.path.dirname(__file__), '../test/compile-fail')
+)
+
+for kw in sys.argv[1:]:
+    test_file = os.path.join(test_dir, 'keyword-%s-as-identifier.rs' % kw)
+
+    # set write permission if file exists, so it can be changed
+    if os.path.exists(test_file):
+        os.chmod(test_file, stat.S_IWUSR)
+
+    with open(test_file, 'wt') as f:
+        f.write(template % (datetime.datetime.now().year, kw, kw))
+
+    # mark file read-only
+    os.chmod(test_file, stat.S_IRUSR|stat.S_IRGRP|stat.S_IROTH)

src/test/compile-fail/keyword-as-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py as'
+
+fn main() {
+    let as = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-break-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py break'
+
+fn main() {
+    let break = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-do-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py do'
+
+fn main() {
+    let do = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-else-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py else'
+
+fn main() {
+    let else = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-enum-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py enum'
+
+fn main() {
+    let enum = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-extern-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py extern'
+
+fn main() {
+    let extern = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-false-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py false'
+
+fn main() {
+    let false = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-fn-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py fn'
+
+fn main() {
+    let fn = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-for-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py for'
+
+fn main() {
+    let for = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-if-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py if'
+
+fn main() {
+    let if = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-impl-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py impl'
+
+fn main() {
+    let impl = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-let-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py let'
+
+fn main() {
+    let let = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-loop-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py loop'
+
+fn main() {
+    let loop = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-match-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py match'
+
+fn main() {
+    let match = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-mod-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py mod'
+
+fn main() {
+    let mod = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-mut-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py mut'
+
+fn main() {
+    let mut = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-priv-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py priv'
+
+fn main() {
+    let priv = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-pub-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py pub'
+
+fn main() {
+    let pub = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-ref-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py ref'
+
+fn main() {
+    let ref = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-return-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py return'
+
+fn main() {
+    let return = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-self-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py self'
+
+fn main() {
+    let self = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-static-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py static'
+
+fn main() {
+    let static = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-struct-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py struct'
+
+fn main() {
+    let struct = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-super-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py super'
+
+fn main() {
+    let super = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-trait-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py trait'
+
+fn main() {
+    let trait = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-true-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py true'
+
+fn main() {
+    let true = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-type-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py type'
+
+fn main() {
+    let type = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-unsafe-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py unsafe'
+
+fn main() {
+    let unsafe = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-use-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py use'
+
+fn main() {
+    let use = "foo"; //~ error: ident
+}

src/test/compile-fail/keyword-while-as-identifier.rs

+// Copyright 2013 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-tests.py while'
+
+fn main() {
+    let while = "foo"; //~ error: ident
+}