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 namespace art {
25 namespace verifier {
26 
27 // RAII to inject a newline after a message.
28 struct ScopedNewLine {
ScopedNewLineScopedNewLine29   explicit ScopedNewLine(std::ostream& os) : stream(os) {}
30 
ScopedNewLineScopedNewLine31   ScopedNewLine(ScopedNewLine&& other) : stream(other.stream), active(other.active) {
32     other.active = false;
33   }
34 
35   ScopedNewLine(ScopedNewLine&) = delete;
36   ScopedNewLine& operator=(ScopedNewLine&) = delete;
37 
~ScopedNewLineScopedNewLine38   ~ScopedNewLine() {
39     if (active) {
40       stream << std::endl;
41     }
42   }
43 
44   template <class T>
45   ScopedNewLine& operator<<(const T& t) {
46     DCHECK(active);
47     stream << t;
48     return *this;
49   }
50 
51   ScopedNewLine& operator<<(std::ostream& (*f)(std::ostream&)) {
52     DCHECK(active);
53     stream << f;
54     return *this;
55   }
56 
57   std::ostream& stream;
58   bool active = true;
59 };
60 
61 }  // namespace verifier
62 }  // namespace art
63 
64 #endif  // ART_RUNTIME_VERIFIER_SCOPED_NEWLINE_H_
65