LLVM to LLVM with Address Sanitize

Question

I would like to know if it's possible to generate an LLVM file (.ll) with Address Sanitizer. I have a command that I want to execute, which is:

clang -S -emit-llvm -fsanitize=address sample.ll -o sample_asan.ll

When I input the LLVM files, I want to get an address-sanitized LLVM file as the output. Currently, I am unable to generate an ASAN (Address Sanitizer) LLVM file.

Could you please guide me on how to compile and link it?

I tried to compile below c file. (bof.c)

#include <stdio.h>

void main(){
    char arr[100];
    arr[100] = 'a';
}

generate llvm command

clang -S -emit-llvm bof.c -o bof.ll

and this is the reusult.

; ModuleID = 'bof.c'
source_filename = "bof.c"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"

; Function Attrs: noinline nounwind optnone uwtable
define dso_local void @main() #0 {
  %1 = alloca [100 x i8], align 16
  %2 = getelementptr inbounds [100 x i8], [100 x i8]* %1, i64 0, i64 100
  store i8 97, i8* %2, align 4
  ret void
}

attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }

!llvm.module.flags = !{!0, !1, !2}
!llvm.ident = !{!3}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 7, !"uwtable", i32 1}
!2 = !{i32 7, !"frame-pointer", i32 2}
!3 = !{!"Ubuntu clang version 13.0.1-2ubuntu2.2"}

now, I generate llvm file(bof.ll) to llvm file with asan (bof_asan.ll).

clang -S -emit-llvm -fsanitize=address bof.ll -o bof_asan.ll

But, there are no insertion of asan.

; ModuleID = 'bof.ll'
source_filename = "bof.c"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"

@llvm.used = appending global [1 x i8*] [i8* bitcast (void ()* @asan.module_ctor to i8*)], section "llvm.metadata"
@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 1, void ()* @asan.module_ctor, i8* null }]

; Function Attrs: noinline nounwind optnone uwtable
define dso_local void @main() #0 {
  %1 = alloca [100 x i8], align 16
  %2 = getelementptr inbounds [100 x i8], [100 x i8]* %1, i64 0, i64 100
  store i8 97, i8* %2, align 4
  ret void
}

declare void @__asan_before_dynamic_init(i64)

declare void @__asan_after_dynamic_init()

declare void @__asan_register_globals(i64, i64)

declare void @__asan_unregister_globals(i64, i64)

declare void @__asan_register_image_globals(i64)

declare void @__asan_unregister_image_globals(i64)

declare void @__asan_register_elf_globals(i64, i64, i64)

declare void @__asan_unregister_elf_globals(i64, i64, i64)

declare void @__asan_init()

; Function Attrs: nounwind uwtable
define internal void @asan.module_ctor() #1 {
  call void @__asan_init()
  call void @__asan_version_mismatch_check_v8()
  ret void
}

declare void @__asan_version_mismatch_check_v8()

attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nounwind uwtable "frame-pointer"="all" }

!llvm.module.flags = !{!0, !1, !2}
!llvm.ident = !{!3}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 7, !"uwtable", i32 1}
!2 = !{i32 7, !"frame-pointer", i32 2}
!3 = !{!"Ubuntu clang version 13.0.1-2ubuntu2.2"}