How to get objc-arc related function call in LLVM IR file (original) (raw)

i have a objective-c file

@implementation IRTest

-(id)methodb{
    NSObject *obj  =[[NSObject alloc] init];// for arc rules, the compiler will generate objc_autorelease for the obj
    return obj;
}
@end

i compile it to llvm ir use

clang -emit-llvm -S -c -O2 -x objective-c -c IRTest.m 

i got the IR

define internal ptr @"\01-[IRTest methodb]"(ptr nocapture readnone %0, ptr nocapture readnone %1) #1 {
  %3 = load ptr, ptr @"OBJC_CLASSLIST_REFERENCES_$_", align 8
  %4 = tail call ptr @objc_alloc_init(ptr %3)
  ret ptr %4
}

then, i compile it to mach o binary, i got

    mov    x1, x0
     ldr    x0, [sp, #0x8]
     str    x1, [sp, #0x10]
    mov    x1, #0x0
    bl     0x100003ed4               ; symbol stub for: objc_storeStrong
     ldr    x0, [sp, #0x10]
    ldp    x29, x30, [sp, #0x30]
   add    sp, sp, #0x40
   b      0x100003eb0               ; symbol stub for: objc_autoreleaseReturnValue

where is the objc_storeStrong & objc_autoreleaseReturnValue call going ??

This seems like a codegen question.
I can’t comment on this from the Static Analyzer’s side.

dqjk May 20, 2024, 4:05am 3

thank you for reply, I find the problem and have resovle it.
it’s the compile args, I retrive the compile args from xcode, i can got the arc methods in ir code.