session-ios/src/Util/Asserts.h

//
//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
//

#import <Foundation/Foundation.h>

#ifndef OWSAssert

#ifdef DEBUG

#define USE_ASSERTS

#define CONVERT_TO_STRING(X) #X
#define CONVERT_EXPR_TO_STRING(X) CONVERT_TO_STRING(X)

#define OWSAssert(X) \
if (!(X)) { \
NSLog(@"Assertion failed: %s", CONVERT_EXPR_TO_STRING(X)); \
NSAssert(0, @"Assertion failed: %s", CONVERT_EXPR_TO_STRING(X)); \
}

// OWSAssert() should be used in Obj-C and Swift methods.
// OWSCAssert() should be used in free functions.
#define OWSCAssert(X) \
if (!(X)) { \
NSLog(@"Assertion failed: %s", CONVERT_EXPR_TO_STRING(X)); \
NSCAssert(0, @"Assertion failed: %s", CONVERT_EXPR_TO_STRING(X)); \
}

#else

#define OWSAssert(X)
#define OWSCAssert(X)

#endif

#endif

#pragma mark - Singleton Asserts

// The "singleton asserts" can be used to ensure
// that we only create a singleton once.
//
// The simplest way to use them is the OWSSingletonAssert() macro.
// It is intended to be used inside the singleton's initializer.
//
// If, however, a singleton has multiple possible initializers,
// you need to:
//
// 1. Use OWSSingletonAssertFlag() outside the class definition.
// 2. Use OWSSingletonAssertInit() in each initializer.
#ifdef DEBUG

#define OWSSingletonAssertFlag() static BOOL _isSingletonCreated = NO;

#define OWSSingletonAssertInit()                                                                                       \
    @synchronized([self class])                                                                                        \
    {                                                                                                                  \
        OWSAssert(!_isSingletonCreated);                                                                               \
        _isSingletonCreated = YES;                                                                                     \
    }

#define OWSSingletonAssert() OWSSingletonAssertFlag() OWSSingletonAssertInit()

#else

#define OWSSingletonAssertFlag()
#define OWSSingletonAssertInit()
#define OWSSingletonAssert()

#endif