1 /*
2  * Copyright (C) 2007 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 #define LOG_TAG "CallStack"
18 
19 #include <utils/Printer.h>
20 #include <utils/Errors.h>
21 #include <utils/Log.h>
22 
23 #include <backtrace/Backtrace.h>
24 
25 #define CALLSTACK_WEAK  // Don't generate weak definitions.
26 #include <utils/CallStack.h>
27 
28 namespace android {
29 
CallStack()30 CallStack::CallStack() {
31 }
32 
CallStack(const char * logtag,int32_t ignoreDepth)33 CallStack::CallStack(const char* logtag, int32_t ignoreDepth) {
34     this->update(ignoreDepth+1);
35     this->log(logtag);
36 }
37 
~CallStack()38 CallStack::~CallStack() {
39 }
40 
update(int32_t ignoreDepth,pid_t tid)41 void CallStack::update(int32_t ignoreDepth, pid_t tid) {
42     mFrameLines.clear();
43 
44     std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, tid));
45     if (!backtrace->Unwind(ignoreDepth)) {
46         ALOGW("%s: Failed to unwind callstack.", __FUNCTION__);
47     }
48     for (size_t i = 0; i < backtrace->NumFrames(); i++) {
49       mFrameLines.push_back(String8(backtrace->FormatFrameData(i).c_str()));
50     }
51 }
52 
log(const char * logtag,android_LogPriority priority,const char * prefix) const53 void CallStack::log(const char* logtag, android_LogPriority priority, const char* prefix) const {
54     LogPrinter printer(logtag, priority, prefix, /*ignoreBlankLines*/false);
55     print(printer);
56 }
57 
dump(int fd,int indent,const char * prefix) const58 void CallStack::dump(int fd, int indent, const char* prefix) const {
59     FdPrinter printer(fd, indent, prefix);
60     print(printer);
61 }
62 
toString(const char * prefix) const63 String8 CallStack::toString(const char* prefix) const {
64     String8 str;
65 
66     String8Printer printer(&str, prefix);
67     print(printer);
68 
69     return str;
70 }
71 
print(Printer & printer) const72 void CallStack::print(Printer& printer) const {
73     for (size_t i = 0; i < mFrameLines.size(); i++) {
74         printer.printLine(mFrameLines[i]);
75     }
76 }
77 
78 // The following four functions may be used via weak symbol references from libutils.
79 // Clients assume that if any of these symbols are available, then deleteStack() is.
80 
81 #ifdef WEAKS_AVAILABLE
82 
getCurrentInternal(int ignoreDepth)83 CallStack::CallStackUPtr CallStack::getCurrentInternal(int ignoreDepth) {
84     CallStack::CallStackUPtr stack(new CallStack());
85     stack->update(ignoreDepth + 1);
86     return stack;
87 }
88 
logStackInternal(const char * logtag,const CallStack * stack,android_LogPriority priority)89 void CallStack::logStackInternal(const char* logtag, const CallStack* stack,
90                                  android_LogPriority priority) {
91     stack->log(logtag, priority);
92 }
93 
stackToStringInternal(const char * prefix,const CallStack * stack)94 String8 CallStack::stackToStringInternal(const char* prefix, const CallStack* stack) {
95     return stack->toString(prefix);
96 }
97 
deleteStack(CallStack * stack)98 void CallStack::deleteStack(CallStack* stack) {
99     delete stack;
100 }
101 
102 #endif // WEAKS_AVAILABLE
103 
104 }; // namespace android
105