$ 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 2>&1 | FileCheck %s RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/extern/extern.out -o %t.dSYM --verbose 2>&1 | FileCheck %s CHECK-NOT: could not find object file symbol for symbol _baz CHECK: { sym: _foo, objAddr: 0x0, binAddr: 0x100007F58, size: 0x20 } CHECK: { sym: _baz, objAddr: 0x0, binAddr: 0x100007F58, size: 0x0 }