// RUN: %clang_cc1 -triple x86_64-linux -Wunused -x c -verify %s // RUN: %clang_cc1 -triple x86_64-linux -Wunused -verify=expected,cxx %s #ifdef __cplusplus extern "C" { #endif static int f(void) { return 42; } int g(void) __attribute__((alias("f"))); static int foo [] = { 42, 0xDEAD }; // cxx-warning{{variable 'foo' is not needed and will not be emitted}} extern typeof(foo) bar __attribute__((unused, alias("foo"))); /// https://github.com/llvm/llvm-project/issues/88593 /// We report a warning in C++ mode because the internal linkage `resolver` gets /// mangled as it does not have a language linkage. GCC does not mangle /// `resolver` or report a warning. static int (*resolver(void))(void) { return f; } // cxx-warning{{unused function 'resolver'}} int ifunc(void) __attribute__((ifunc("resolver"))); static int __attribute__((overloadable)) f0(int x) { return x; } static float __attribute__((overloadable)) f0(float x) { return x; } // expected-warning{{unused function 'f0'}} int g0(void) __attribute__((alias("_ZL2f0i"))); #ifdef __cplusplus static int f1() { return 42; } int g1(void) __attribute__((alias("_ZL2f1v"))); } /// We demangle alias/ifunc target and mark all found functions as used. static int f2(int) { return 42; } // cxx-warning{{unused function 'f2'}} static int f2() { return 42; } int g2() __attribute__((alias("_ZL2f2v"))); static int (*resolver1())() { return f; } // cxx-warning{{unused function 'resolver1'}} static int (*resolver1(int))() { return f; } int ifunc1() __attribute__((ifunc("_ZL9resolver1i"))); /// TODO: We should report "unused function" for f3(int). namespace ns { static int f3(int) { return 42; } // cxx-warning{{unused function 'f3'}} static int f3() { return 42; } // cxx-warning{{unused function 'f3'}} int g3() __attribute__((alias("_ZN2nsL2f3Ev"))); } template static void *f4(T) { return nullptr; } static void *f4() { return nullptr; } // cxx-warning{{unused function 'f4'}} extern void g4_int() __attribute__((ifunc("_ZL2f4IiEPvT_"))); extern void g4_char() __attribute__((ifunc("_ZL2f4IcEPcT_"))); // rejected by CodeGen void *use4 = f4(0); #endif