clang/test/CodeGenCXX/pass-object-size.cpp

// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -O0 %s -o - 2>&1 -std=c++11 | FileCheck %s

int gi;

namespace lambdas {
// CHECK-LABEL: define void @_ZN7lambdas7LambdasEPc
void Lambdas(char *ptr) {
  auto L1 = [](void *const p __attribute__((pass_object_size(0)))) {
    return __builtin_object_size(p, 0);
  };

  int i = 0;
  auto L2 = [&i](void *const p __attribute__((pass_object_size(0)))) {
    return __builtin_object_size(p, 0) + i;
  };

  // CHECK: @llvm.objectsize
  gi = L1(ptr);
  // CHECK: @llvm.objectsize
  gi = L2(ptr);
}

// CHECK-DAG: define internal i64 @"_ZZN7lambdas7LambdasEPcENK3$_0clEPvU17pass_object_size0"
// CHECK-NOT: call i64 @llvm.objectsize
// CHECK-DAG: define internal i64 @"_ZZN7lambdas7LambdasEPcENK3$_1clEPvU17pass_object_size0"
// CHECK-NOT: call i64 @llvm.objectsize
}

// This is here instead of in Sema/ because we need to check to make sure the
// proper function is called. If it's not, we'll end up with assertion errors.
namespace addrof {
void OvlFoo(void *const __attribute__((pass_object_size(0)))) {}
void OvlFoo(int *const) {}

// CHECK: define void @_ZN6addrof4TestEv
void Test() {
  // Treating parens-only calls as though they were direct is consistent with
  // how we handle other implicitly unaddressable functions (e.g. builtins).
  // CHECK: call void @_ZN6addrof6OvlFooEPvU17pass_object_size0
  (OvlFoo)(nullptr);

  // CHECK: call void @_ZN6addrof6OvlFooEPi
  (&OvlFoo)(nullptr);
}
}

namespace delegate {
  struct A {
    A(void *const p __attribute__((pass_object_size(0))));
  };
  A::A(void *const p __attribute__((pass_object_size(0)))) {}
  // Ensure that we forward the size through a delegating constructor call.
  // CHECK: define void @_ZN8delegate1AC1EPvU17pass_object_size0({{[^,]*}}, i8*{{[^,]*}}, i64{{[^,]*}})
  // CHECK: call void @_ZN8delegate1AC2EPvU17pass_object_size0({{[^,]*}}, i8*{{[^,]*}}, i64{{[^,]*}})
}

namespace variadic {
// We had an issue where variadic member/operator calls with pass_object_size
// would cause crashes.

struct AsCtor {
  AsCtor(const char *const c __attribute__((pass_object_size(0))), double a,
         ...) {}
};

struct AsMember {
  void bar(const char *const c __attribute__((pass_object_size(0))), double a,
           ...) {}
  void operator()(const char *const c __attribute__((pass_object_size(0))),
                  double a, ...) {}
};

// CHECK-LABEL: define void @_ZN8variadic4testEv()
void test() {
  // CHECK-RE: call{{[^@]+}}@_ZN8variadic6AsCtorC1EPKcU17pass_object_size0dz
  AsCtor("a", 1.0);
  // CHECK-RE: call{{[^@]+}}@_ZN8variadic8AsMember3barEPKcU17pass_object_size0dz
  AsMember{}.bar("a", 1.0);
  // CHECK-RE: call{{[^@]+}}@_ZN8variadic8AsMemberclEPKcU17pass_object_size0dz
  AsMember{}("a", 1.0);
}
}