How C++ RAII work?

main.cpp

// Compile with clang -S -emit-llvm -O1 main.cpp
#include <cstdio>

struct Apple {
    Apple() {
        puts("CTOR");
    }
    ~Apple() {
        puts("DTOR");
    }
};

int foo() {
    Apple apple;
}

int main() {

    Apple apple;
    foo();
    return 0;
}

main.ll

; ModuleID = 'main.cpp'
source_filename = "main.cpp"
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.13.0"

%struct.Apple = type { i8 }

@.str = private unnamed_addr constant [5 x i8] c"CTOR\00", align 1
@.str.1 = private unnamed_addr constant [5 x i8] c"DTOR\00", align 1

; Function Attrs: ssp uwtable
define i32 @_Z3foov() local_unnamed_addr #0 {
  %1 = alloca %struct.Apple, align 1
  %2 = getelementptr inbounds %struct.Apple, %struct.Apple* %1, i64 0, i32 0
  call void @llvm.lifetime.start(i64 1, i8* nonnull %2) #5
  call void @_ZN5AppleC1Ev(%struct.Apple* nonnull %1)
  call void @_ZN5AppleD1Ev(%struct.Apple* nonnull %1)
  call void @llvm.lifetime.end(i64 1, i8* nonnull %2) #5
  ret i32 undef
}

; Function Attrs: argmemonly nounwind
declare void @llvm.lifetime.start(i64, i8* nocapture) #1

; Function Attrs: ssp uwtable
define linkonce_odr void @_ZN5AppleC1Ev(%struct.Apple*) unnamed_addr #0 align 2 {
  tail call void @_ZN5AppleC2Ev(%struct.Apple* %0)
  ret void
}

; Function Attrs: ssp uwtable
define linkonce_odr void @_ZN5AppleD1Ev(%struct.Apple*) unnamed_addr #0 align 2 {
  tail call void @_ZN5AppleD2Ev(%struct.Apple* %0)
  ret void
}

; Function Attrs: argmemonly nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture) #1

; Function Attrs: norecurse ssp uwtable
define i32 @main() local_unnamed_addr #2 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
  %1 = alloca %struct.Apple, align 1
  %2 = getelementptr inbounds %struct.Apple, %struct.Apple* %1, i64 0, i32 0
  call void @llvm.lifetime.start(i64 1, i8* nonnull %2) #5
  call void @_ZN5AppleC1Ev(%struct.Apple* nonnull %1)
  %3 = invoke i32 @_Z3foov()
          to label %4 unwind label %5

; <label>:4:                                      ; preds = %0
  call void @_ZN5AppleD1Ev(%struct.Apple* nonnull %1)
  call void @llvm.lifetime.end(i64 1, i8* nonnull %2) #5
  ret i32 0

; <label>:5:                                      ; preds = %0
  %6 = landingpad { i8*, i32 }
          cleanup
  invoke void @_ZN5AppleD1Ev(%struct.Apple* nonnull %1)
          to label %7 unwind label %8

; <label>:7:                                      ; preds = %5
  call void @llvm.lifetime.end(i64 1, i8* nonnull %2) #5
  resume { i8*, i32 } %6

; <label>:8:                                      ; preds = %5
  %9 = landingpad { i8*, i32 }
          catch i8* null
  %10 = extractvalue { i8*, i32 } %9, 0
  call void @__clang_call_terminate(i8* %10) #6
  unreachable
}

declare i32 @__gxx_personality_v0(...)

; Function Attrs: noinline noreturn nounwind
define linkonce_odr hidden void @__clang_call_terminate(i8*) local_unnamed_addr #3 {
  %2 = tail call i8* @__cxa_begin_catch(i8* %0) #5
  tail call void @_ZSt9terminatev() #6
  unreachable
}

declare i8* @__cxa_begin_catch(i8*) local_unnamed_addr

declare void @_ZSt9terminatev() local_unnamed_addr

; Function Attrs: ssp uwtable
define linkonce_odr void @_ZN5AppleC2Ev(%struct.Apple*) unnamed_addr #0 align 2 {
  %2 = tail call i32 @puts(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0))
  ret void
}

; Function Attrs: nounwind
declare i32 @puts(i8* nocapture readonly) local_unnamed_addr #4

; Function Attrs: ssp uwtable
define linkonce_odr void @_ZN5AppleD2Ev(%struct.Apple*) unnamed_addr #0 align 2 {
  %2 = tail call i32 @puts(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
  ret void
}

attributes #0 = { ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+fxsr,+mmx,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { argmemonly nounwind }
attributes #2 = { norecurse ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+fxsr,+mmx,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #3 = { noinline noreturn nounwind }
attributes #4 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+fxsr,+mmx,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #5 = { nounwind }
attributes #6 = { noreturn nounwind }

!llvm.module.flags = !{!0}
!llvm.ident = !{!1}

!0 = !{i32 1, !"PIC Level", i32 2}
!1 = !{!"Apple LLVM version 9.0.0 (clang-900.0.39.2)"}