Runtime EXC_BAD_ACCESS crash in libswiftCore.dylib`__swift::__runtime::llvm::hash_combine<__swift::__runtime::llvm::hash_code, __swift::__runtime::llvm::StringRef>:

[darronschall]

Description

I made a small mistake that the compiler (perhaps erroneously?) accepted. The resulting binary crashes at runtime.

I've seen a few different stack dumps for this particular scenario. The one I've included is the one that happens from the simple reproducible test case. This has also manifested as:

libswiftCore.dylib`swift::ConcurrentReadableHashMap<swift::HashMapElementWrapper<(anonymous namespace)::TupleCacheEntry>, swift::Mutex>::find<(anonymous namespace)::TupleCacheEntry::Key>

libswiftCore.dylib`getCache(swift::TargetTypeContextDescriptor<swift::InProcess> const&) ()

Reproduction

import SwiftUI

struct ContentView: View {
    var body: some View {
        EmptyView()
        // NOTE: Missing leading `.` here to chain the method call; causes a runtime crash.
        fullScreenCover(isPresented: .constant(false)) {
            Text("Cover")
        }
    }
}

Stack dump

libswiftCore.dylib`__swift::__runtime::llvm::hash_combine<__swift::__runtime::llvm::hash_code, __swift::__runtime::llvm::StringRef>:
    0x19328ed2c <+0>:   sub    sp, sp, #0xc0
    0x19328ed30 <+4>:   stp    x20, x19, [sp, #0xa0]
    0x19328ed34 <+8>:   stp    x29, x30, [sp, #0xb0]
    0x19328ed38 <+12>:  add    x29, sp, #0xb0
    0x19328ed3c <+16>:  str    xzr, [sp, #0x80]
    0x19328ed40 <+20>:  movi.2d v0, #0000000000000000
    0x19328ed44 <+24>:  stp    q0, q0, [sp, #0x60]
    0x19328ed48 <+28>:  stp    q0, q0, [sp, #0x40]
    0x19328ed4c <+32>:  stp    q0, q0, [sp, #0x20]
->  0x19328ed50 <+36>:  str    q0, [sp, #0x10]
    0x19328ed54 <+40>:  adrp   x8, 365688
    0x19328ed58 <+44>:  add    x8, x8, #0xed8            ; guard variable for __swift::__runtime::llvm::hashing::detail::get_execution_seed()::seed
    0x19328ed5c <+48>:  ldaprb w8, [x8]
    0x19328ed60 <+52>:  adrp   x19, 365688
    0x19328ed64 <+56>:  tbz    w8, #0x0, 0x19328edcc     ; <+160>
    0x19328ed68 <+60>:  ldr    x8, [x19, #0xfa0]
    0x19328ed6c <+64>:  add    x9, sp, #0x10
    0x19328ed70 <+68>:  add    x19, x9, #0x40
    0x19328ed74 <+72>:  ldr    x10, [x0]
    0x19328ed78 <+76>:  orr    x20, x9, #0x8
    0x19328ed7c <+80>:  str    x8, [sp, #0x88]
    0x19328ed80 <+84>:  str    x10, [sp, #0x10]
    0x19328ed84 <+88>:  stur   xzr, [x29, #-0x18]
    0x19328ed88 <+92>:  ldp    x0, x1, [x1]
    0x19328ed8c <+96>:  bl     0x1932bced0               ; __swift::__runtime::llvm::hash_value(__swift::__runtime::llvm::StringRef)
    0x19328ed90 <+100>: mov    x4, x0
    0x19328ed94 <+104>: add    x0, sp, #0x10
    0x19328ed98 <+108>: sub    x1, x29, #0x18
    0x19328ed9c <+112>: mov    x2, x20
    0x19328eda0 <+116>: mov    x3, x19
    0x19328eda4 <+120>: bl     0x19328b29c               ; char* __swift::__runtime::llvm::hashing::detail::hash_combine_recursive_helper::combine_data<unsigned long>(unsigned long&, char*, char*, unsigned long)
    0x19328eda8 <+124>: mov    x2, x0
    0x19328edac <+128>: ldur   x1, [x29, #-0x18]
    0x19328edb0 <+132>: add    x0, sp, #0x10
    0x19328edb4 <+136>: mov    x3, x19
    0x19328edb8 <+140>: bl     0x19328b478               ; __swift::__runtime::llvm::hashing::detail::hash_combine_recursive_helper::combine(unsigned long, char*, char*)
    0x19328edbc <+144>: ldp    x29, x30, [sp, #0xb0]
    0x19328edc0 <+148>: ldp    x20, x19, [sp, #0xa0]
    0x19328edc4 <+152>: add    sp, sp, #0xc0
    0x19328edc8 <+156>: ret    
    0x19328edcc <+160>: adrp   x8, 365688
    0x19328edd0 <+164>: add    x8, x8, #0xed8            ; guard variable for __swift::__runtime::llvm::hashing::detail::get_execution_seed()::seed
    0x19328edd4 <+168>: str    x0, [sp, #0x8]
    0x19328edd8 <+172>: mov    x0, x8
    0x19328eddc <+176>: mov    x20, x1
    0x19328ede0 <+180>: bl     0x193309564               ; symbol stub for: __cxa_guard_acquire
    0x19328ede4 <+184>: mov    x1, x20
    0x19328ede8 <+188>: mov    x8, x0
    0x19328edec <+192>: ldr    x0, [sp, #0x8]
    0x19328edf0 <+196>: cbz    w8, 0x19328ed68           ; <+60>
    0x19328edf4 <+200>: adrp   x8, 365725
    0x19328edf8 <+204>: add    x8, x8, #0xb08            ; __swift::__runtime::llvm::hashing::detail::fixed_seed_override
    0x19328edfc <+208>: ldr    x8, [x8]
    0x19328ee00 <+212>: mov    x9, #0x8ccd
    0x19328ee04 <+216>: movk   x9, #0xed55, lsl #16
    0x19328ee08 <+220>: movk   x9, #0xafd7, lsl #32
    0x19328ee0c <+224>: movk   x9, #0xff51, lsl #48
    0x19328ee10 <+228>: cmp    x8, #0x0
    0x19328ee14 <+232>: csel   x8, x9, x8, eq
    0x19328ee18 <+236>: str    x8, [x19, #0xfa0]
    0x19328ee1c <+240>: adrp   x0, 365688
    0x19328ee20 <+244>: add    x0, x0, #0xed8            ; guard variable for __swift::__runtime::llvm::hashing::detail::get_execution_seed()::seed
    0x19328ee24 <+248>: bl     0x193309570               ; symbol stub for: __cxa_guard_release
    0x19328ee28 <+252>: ldr    x0, [sp, #0x8]
    0x19328ee2c <+256>: mov    x1, x20
    0x19328ee30 <+260>: b      0x19328ed68               ; <+60>

Expected behavior

Can a compiler error be generated here? It was my mistake that I accidentally forgot to use . to chain the method call.

Environment

Xcode 15.3 / Swift 5.9

Additional information

No response