1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_RUNTIME_VERIFIER_SCOPED_NEWLINE_H_
18 #define ART_RUNTIME_VERIFIER_SCOPED_NEWLINE_H_
19 
20 #include <ostream>
21 
22 #include <android-base/logging.h>
23 
24 #include "base/macros.h"
25 
26 namespace art HIDDEN {
27 namespace verifier {
28 
29 // RAII to inject a newline after a message.
30 struct ScopedNewLine {
ScopedNewLineScopedNewLine31   explicit ScopedNewLine(std::ostream& os) : stream(os) {}
32 
ScopedNewLineScopedNewLine33   ScopedNewLine(ScopedNewLine&& other) noexcept : stream(other.stream), active(other.active) {
34     other.active = false;
35   }
36 
37   ScopedNewLine(ScopedNewLine&) = delete;
38   ScopedNewLine& operator=(ScopedNewLine&) = delete;
39 
~ScopedNewLineScopedNewLine40   ~ScopedNewLine() {
41     if (active) {
42       stream << std::endl;
43     }
44   }
45 
46   template <class T>
47   ScopedNewLine& operator<<(const T& t) {
48     DCHECK(active);
49     stream << t;
50     return *this;
51   }
52 
53   ScopedNewLine& operator<<(std::ostream& (*f)(std::ostream&)) {
54     DCHECK(active);
55     stream << f;
56     return *this;
57   }
58 
59   std::ostream& stream;
60   bool active = true;
61 };
62 
63 }  // namespace verifier
64 }  // namespace art
65 
66 #endif  // ART_RUNTIME_VERIFIER_SCOPED_NEWLINE_H_
67