Bug Summary

File:libclamav/c++/llvm/lib/System/Mutex.cpp
Location:line 80, column 5
Description:Value stored to 'errorcode' is never read

Annotated Source Code

1//===- Mutex.cpp - Mutual Exclusion Lock ------------------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the llvm::sys::Mutex class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Config/config.h"
15#include "llvm/System/Mutex.h"
16
17//===----------------------------------------------------------------------===//
18//=== WARNING: Implementation here must contain only TRULY operating system
19//=== independent code.
20//===----------------------------------------------------------------------===//
21
22#if !defined(ENABLE_THREADS1) || ENABLE_THREADS1 == 0
23// Define all methods as no-ops if threading is explicitly disabled
24namespace llvm {
25using namespace sys;
26MutexImpl::MutexImpl( bool recursive) { }
27MutexImpl::~MutexImpl() { }
28bool MutexImpl::acquire() { return true; }
29bool MutexImpl::release() { return true; }
30bool MutexImpl::tryacquire() { return true; }
31}
32#else
33
34#if defined(HAVE_PTHREAD_H1) && defined(HAVE_PTHREAD_MUTEX_LOCK1)
35
36#include <cassert>
37#include <pthread.h>
38#include <stdlib.h>
39
40namespace llvm {
41using namespace sys;
42
43
44// This variable is useful for situations where the pthread library has been
45// compiled with weak linkage for its interface symbols. This allows the
46// threading support to be turned off by simply not linking against -lpthread.
47// In that situation, the value of pthread_mutex_init will be 0 and
48// consequently pthread_enabled will be false. In such situations, all the
49// pthread operations become no-ops and the functions all return false. If
50// pthread_mutex_init does have an address, then mutex support is enabled.
51// Note: all LLVM tools will link against -lpthread if its available since it
52// is configured into the LIBS variable.
53// Note: this line of code generates a warning if pthread_mutex_init is not
54// declared with weak linkage. It's safe to ignore the warning.
55static const bool pthread_enabled = true;
56
57// Construct a Mutex using pthread calls
58MutexImpl::MutexImpl( bool recursive)
59 : data_(0)
60{
61 if (pthread_enabled)
62 {
63 // Declare the pthread_mutex data structures
64 pthread_mutex_t* mutex =
65 static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t)));
66 pthread_mutexattr_t attr;
67
68 // Initialize the mutex attributes
69 int errorcode = pthread_mutexattr_init(&attr);
70 assert(errorcode == 0)((errorcode == 0) ? static_cast<void> (0) : __assert_fail
("errorcode == 0", "llvm/lib/System/Mutex.cpp", 70, __PRETTY_FUNCTION__
));
71
72 // Initialize the mutex as a recursive mutex, if requested, or normal
73 // otherwise.
74 int kind = ( recursive ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
75 errorcode = pthread_mutexattr_settype(&attr, kind);
76 assert(errorcode == 0)((errorcode == 0) ? static_cast<void> (0) : __assert_fail
("errorcode == 0", "llvm/lib/System/Mutex.cpp", 76, __PRETTY_FUNCTION__
));
77
78#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__)
79 // Make it a process local mutex
80 errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATEPTHREAD_PROCESS_PRIVATE);
Value stored to 'errorcode' is never read
81#endif
82
83 // Initialize the mutex
84 errorcode = pthread_mutex_init(mutex, &attr);
85 assert(errorcode == 0)((errorcode == 0) ? static_cast<void> (0) : __assert_fail
("errorcode == 0", "llvm/lib/System/Mutex.cpp", 85, __PRETTY_FUNCTION__
));
86
87 // Destroy the attributes
88 errorcode = pthread_mutexattr_destroy(&attr);
89 assert(errorcode == 0)((errorcode == 0) ? static_cast<void> (0) : __assert_fail
("errorcode == 0", "llvm/lib/System/Mutex.cpp", 89, __PRETTY_FUNCTION__
));
90
91 // Assign the data member
92 data_ = mutex;
93 }
94}
95
96// Destruct a Mutex
97MutexImpl::~MutexImpl()
98{
99 if (pthread_enabled)
100 {
101 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
102 assert(mutex != 0)((mutex != 0) ? static_cast<void> (0) : __assert_fail (
"mutex != 0", "llvm/lib/System/Mutex.cpp", 102, __PRETTY_FUNCTION__
));
103 pthread_mutex_destroy(mutex);
104 free(mutex);
105 }
106}
107
108bool
109MutexImpl::acquire()
110{
111 if (pthread_enabled)
112 {
113 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
114 assert(mutex != 0)((mutex != 0) ? static_cast<void> (0) : __assert_fail (
"mutex != 0", "llvm/lib/System/Mutex.cpp", 114, __PRETTY_FUNCTION__
));
115
116 int errorcode = pthread_mutex_lock(mutex);
117 return errorcode == 0;
118 } else return false;
119}
120
121bool
122MutexImpl::release()
123{
124 if (pthread_enabled)
125 {
126 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
127 assert(mutex != 0)((mutex != 0) ? static_cast<void> (0) : __assert_fail (
"mutex != 0", "llvm/lib/System/Mutex.cpp", 127, __PRETTY_FUNCTION__
));
128
129 int errorcode = pthread_mutex_unlock(mutex);
130 return errorcode == 0;
131 } else return false;
132}
133
134bool
135MutexImpl::tryacquire()
136{
137 if (pthread_enabled)
138 {
139 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
140 assert(mutex != 0)((mutex != 0) ? static_cast<void> (0) : __assert_fail (
"mutex != 0", "llvm/lib/System/Mutex.cpp", 140, __PRETTY_FUNCTION__
));
141
142 int errorcode = pthread_mutex_trylock(mutex);
143 return errorcode == 0;
144 } else return false;
145}
146
147}
148
149#elif defined(LLVM_ON_UNIX1)
150#include "Unix/Mutex.inc"
151#elif defined( LLVM_ON_WIN32)
152#include "Win32/Mutex.inc"
153#else
154#warning Neither LLVM_ON_UNIX1 nor LLVM_ON_WIN32 was set in System/Mutex.cpp
155#endif
156#endif
157