iOS throws EXC_BAD_ACCESS error and crashes

Question

I am trying to develop a game with SpriteKit using swift. The game randomly throws this error and the app crashes. I don't know which exactly code causes the crash as I am new to game development.

Error:

EXC_BAD_ACCESS (code=EXC_l386_GPFLT)

Here is the thread 1 UIApplicationMain

    0x10e899d86 <+837>:  movq   %rbx, %rdx
    0x10e899d89 <+840>:  movq   %rax, %rcx
    0x10e899d8c <+843>:  movl   $0x990, %r8d
    0x10e899d92 <+849>:  xorb   %al, %al
    0x10e899d94 <+851>:  callq  *%r12
    0x10e899d97 <+854>:  movq   0xb59bba(%rip), %rsi      ; "class"
    0x10e899d9e <+861>:  movq   0xb7f57b(%rip), %rdi      ; (void *)0x000000010f41df18: UIApplication
    0x10e899da5 <+868>:  callq  *%r12
    0x10e899da8 <+871>:  movq   0xb5aa89(%rip), %rsi      ; "isSubclassOfClass:"
    0x10e899daf <+878>:  movq   %r14, %rdi
    0x10e899db2 <+881>:  movq   %rax, %rdx
    0x10e899db5 <+884>:  callq  *%r12
    0x10e899db8 <+887>:  movq   0xbecb39(%rip), %rbx      ; UIApp
    0x10e899dbf <+894>:  testb  %al, %al
    0x10e899dc1 <+896>:  je     0x10e899dd8               ; <+919>
    0x10e899dc3 <+898>:  movq   0xb59c86(%rip), %rsi      ; "setDelegate:"
    0x10e899dca <+905>:  movq   %rbx, %rdi
    0x10e899dcd <+908>:  movq   %rbx, %rdx
    0x10e899dd0 <+911>:  callq  *0x9b10e2(%rip)           ; (void *)0x000000010ddc7fc0: objc_msgSend
    0x10e899dd6 <+917>:  jmp    0x10e899e14               ; <+979>
    0x10e899dd8 <+919>:  movq   0xb59bd9(%rip), %rsi      ; "alloc"
    0x10e899ddf <+926>:  movq   %r14, %rdi
    0x10e899de2 <+929>:  callq  *%r12
    0x10e899de5 <+932>:  movq   0xb59dd4(%rip), %rsi      ; "init"
    0x10e899dec <+939>:  movq   %rax, %rdi
    0x10e899def <+942>:  callq  *%r12
    0x10e899df2 <+945>:  movq   0xb59e8f(%rip), %rsi      ; "autorelease"
    0x10e899df9 <+952>:  movq   %rax, %rdi
    0x10e899dfc <+955>:  callq  *%r12
    0x10e899dff <+958>:  movq   0xb5aa3a(%rip), %rsi      ; "_setDelegate:assumeOwnership:"
    0x10e899e06 <+965>:  movq   %rbx, %rdi
    0x10e899e09 <+968>:  movq   %rax, %rdx
    0x10e899e0c <+971>:  movl   $0x1, %ecx
    0x10e899e11 <+976>:  callq  *%r12
    0x10e899e14 <+979>:  movq   0xb59a95(%rip), %rsi      ; "release"
    0x10e899e1b <+986>:  movq   -0x30(%rbp), %rdi
    0x10e899e1f <+990>:  callq  *%r12
    0x10e899e22 <+993>:  movq   0xb5aa1f(%rip), %rsi      ; "_run"
    0x10e899e29 <+1000>: movq   0xbecac8(%rip), %rdi      ; UIApp
    0x10e899e30 <+1007>: callq  *%r12
->  0x10e899e33 <+1010>: xorl   %eax, %eax // ERROR LINE HERE
    0x10e899e35 <+1012>: addq   $0x28, %rsp
    0x10e899e39 <+1016>: popq   %rbx
    0x10e899e3a <+1017>: popq   %r12
    0x10e899e3c <+1019>: popq   %r13
    0x10e899e3e <+1021>: popq   %r14
    0x10e899e40 <+1023>: popq   %r15
    0x10e899e42 <+1025>: popq   %rbp
    0x10e899e43 <+1026>: retq   

Here is 0 objc_msgSend

libobjc.A.dylib`objc_msgSend:
    0x10ddc7fc0 <+0>:   testq  %rdi, %rdi
    0x10ddc7fc3 <+3>:   jle    0x10ddc8028               ; <+104>
    0x10ddc7fc5 <+5>:   movq   (%rdi), %r11
    0x10ddc7fc8 <+8>:   movq   %rsi, %r10
->  0x10ddc7fcb <+11>:  andl   0x18(%r11), %r10d
    0x10ddc7fcf <+15>:  shlq   $0x4, %r10
    0x10ddc7fd3 <+19>:  addq   0x10(%r11), %r10
    0x10ddc7fd7 <+23>:  cmpq   (%r10), %rsi
    0x10ddc7fda <+26>:  jne    0x10ddc7fe0               ; <+32>
    0x10ddc7fdc <+28>:  jmpq   *0x8(%r10)
    0x10ddc7fe0 <+32>:  cmpq   $0x0, (%r10)
    0x10ddc7fe4 <+36>:  je     0x10ddc8049               ; <+137>
    0x10ddc7fe6 <+38>:  cmpq   0x10(%r11), %r10
    0x10ddc7fea <+42>:  je     0x10ddc7ff9               ; <+57>
    0x10ddc7fec <+44>:  subq   $0x10, %r10
    0x10ddc7ff0 <+48>:  cmpq   (%r10), %rsi
    0x10ddc7ff3 <+51>:  jne    0x10ddc7fe0               ; <+32>
    0x10ddc7ff5 <+53>:  jmpq   *0x8(%r10)
    0x10ddc7ff9 <+57>:  movl   0x18(%r11), %r10d
    0x10ddc7ffd <+61>:  shlq   $0x4, %r10
    0x10ddc8001 <+65>:  addq   0x10(%r11), %r10
    0x10ddc8005 <+69>:  jmp    0x10ddc8017               ; <+87>
    0x10ddc8007 <+71>:  cmpq   $0x0, (%r10)
    0x10ddc800b <+75>:  je     0x10ddc8049               ; <+137>
    0x10ddc800d <+77>:  cmpq   0x10(%r11), %r10
    0x10ddc8011 <+81>:  je     0x10ddc8020               ; <+96>
    0x10ddc8013 <+83>:  subq   $0x10, %r10
    0x10ddc8017 <+87>:  cmpq   (%r10), %rsi
    0x10ddc801a <+90>:  jne    0x10ddc8007               ; <+71>
    0x10ddc801c <+92>:  jmpq   *0x8(%r10)
    0x10ddc8020 <+96>:  movq   %r11, %rdx
    0x10ddc8023 <+99>:  jmp    0x10ddb2771               ; objc_msgSend_corrupt_cache_error
    0x10ddc8028 <+104>: je     0x10ddc803e               ; <+126>
    0x10ddc802a <+106>: leaq   0x195fd7(%rip), %r11      ; objc_debug_taggedpointer_classes
    0x10ddc8031 <+113>: movq   %rdi, %r10
    0x10ddc8034 <+116>: shrq   $0x3c, %r10
    0x10ddc8038 <+120>: movq   (%r11,%r10,8), %r11
    0x10ddc803c <+124>: jmp    0x10ddc7fc8               ; <+8>
    0x10ddc803e <+126>: xorl   %eax, %eax
    0x10ddc8040 <+128>: xorl   %edx, %edx
    0x10ddc8042 <+130>: xorps  %xmm0, %xmm0
    0x10ddc8045 <+133>: xorps  %xmm1, %xmm1
    0x10ddc8048 <+136>: retq   
    0x10ddc8049 <+137>: enter  $0x88, $0x0
    0x10ddc804d <+141>: movdqa %xmm0, -0x80(%rbp)
    0x10ddc8052 <+146>: pushq  %rax
    0x10ddc8053 <+147>: movdqa %xmm1, -0x70(%rbp)
    0x10ddc8058 <+152>: pushq  %rdi
    0x10ddc8059 <+153>: movdqa %xmm2, -0x60(%rbp)
    0x10ddc805e <+158>: pushq  %rsi
    0x10ddc805f <+159>: movdqa %xmm3, -0x50(%rbp)
    0x10ddc8064 <+164>: pushq  %rdx
    0x10ddc8065 <+165>: movdqa %xmm4, -0x40(%rbp)
    0x10ddc806a <+170>: pushq  %rcx
    0x10ddc806b <+171>: movdqa %xmm5, -0x30(%rbp)
    0x10ddc8070 <+176>: pushq  %r8
    0x10ddc8072 <+178>: movdqa %xmm6, -0x20(%rbp)
    0x10ddc8077 <+183>: pushq  %r9
    0x10ddc8079 <+185>: movdqa %xmm7, -0x10(%rbp)
    0x10ddc807e <+190>: movq   %rdi, %rdi
    0x10ddc8081 <+193>: movq   %rsi, %rsi
    0x10ddc8084 <+196>: movq   %r11, %rdx
    0x10ddc8087 <+199>: callq  0x10ddbc469               ; _class_lookupMethodAndLoadCache3
    0x10ddc808c <+204>: movq   %rax, %r11
    0x10ddc808f <+207>: movdqa -0x80(%rbp), %xmm0
    0x10ddc8094 <+212>: popq   %r9
    0x10ddc8096 <+214>: movdqa -0x70(%rbp), %xmm1
    0x10ddc809b <+219>: popq   %r8
    0x10ddc809d <+221>: movdqa -0x60(%rbp), %xmm2
    0x10ddc80a2 <+226>: popq   %rcx
    0x10ddc80a3 <+227>: movdqa -0x50(%rbp), %xmm3
    0x10ddc80a8 <+232>: popq   %rdx
    0x10ddc80a9 <+233>: movdqa -0x40(%rbp), %xmm4
    0x10ddc80ae <+238>: popq   %rsi
    0x10ddc80af <+239>: movdqa -0x30(%rbp), %xmm5
    0x10ddc80b4 <+244>: popq   %rdi
    0x10ddc80b5 <+245>: movdqa -0x20(%rbp), %xmm6
    0x10ddc80ba <+250>: popq   %rax
    0x10ddc80bb <+251>: movdqa -0x10(%rbp), %xmm7
    0x10ddc80c0 <+256>: leave  
    0x10ddc80c1 <+257>: cmpq   %r11, %r11
    0x10ddc80c4 <+260>: jmpq   *%r11
    0x10ddc80c7 <+263>: nopw   %cs:(%rax,%rax)
    0x10ddc80d6 <+278>: nop    
    0x10ddc80d7 <+279>: nop    
    0x10ddc80d8 <+280>: nop    
    0x10ddc80d9 <+281>: nop    
    0x10ddc80da <+282>: nop    

How can I fix this error and stop the app from crashing?

Answer 1

Hope that you are familiar with the usages of break point in Xcode. Add an All Exception Break Point to see what is happening in side. You will find a good tutorial on Break Point over here .

Answer 2

If you active the console (View -> Debug Area -> Activate Console, or Command + Shift + C) you can see a more detailed report of your crash. If you scroll back up when the app crashes you can see the reason.

To make things more clear I make one of my apps crash on purpose to make a screenshot for you. It shows the reason of the crash below.