llvm/llvm/test/tools/dsymutil/ARM/extern-alias.test

$ cat private_extern.c
__attribute__((visibility("hidden")))
int* foo() {
  int i = 10;
  volatile int* j = &i;
  return j;
}

int* bar() {
  return foo();
}

$ cat extern.c
__attribute__((visibility("hidden")))
int* foo() {
  int i = 10;
  volatile int* j = &i;
  return j;
}

int* bar() {
  return foo();
}

$ cat main.c
int* bar();
int main() {
  return *bar();
}

$ cat alias_list
_foo _baz

$ xcrun --sdk iphoneos clang -g private_extern.c -c -o private_extern.o -target arm64-apple-ios14.0
$ xcrun --sdk iphoneos clang -g main.c -c -o main.o -target arm64-apple-ios14.0
$ xcrun --sdk iphoneos clang private_extern.o main.o -target arm64-apple-ios14.0 -o private_extern.out -Xlinker -alias_list -Xlinker alias_list

RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/private_extern/private_extern.out -o %t.dSYM --verbose | FileCheck %s
RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/extern/extern.out -o %t.dSYM --verbose | FileCheck %s

RUN: dsymutil --linker parallel -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/private_extern/private_extern.out -o %t.dSYM --verbose | FileCheck %s
RUN: dsymutil --linker parallel -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/extern/extern.out -o %t.dSYM --verbose | FileCheck %s

CHECK-NOT: could not find symbol '_baz'
CHECK: { sym: _baz, objAddr: 0x0, binAddr: 0x100007F58, size: 0x0 }
CHECK: { sym: _foo, objAddr: 0x0, binAddr: 0x100007F58, size: 0x20 }