| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| #ifndef StaticConstructors_h |
| #define StaticConstructors_h |
| |
| // We need to avoid having static constructors. We achieve this |
| // with two separate methods for GCC and MSVC. Both methods prevent the static |
| // initializers from being registered and called on program startup. On GCC, we |
| // declare the global objects with a different type that can be POD default |
| // initialized by the linker/loader. On MSVC we use a special compiler feature |
| // to have the CRT ignore our static initializers. The constructors will never |
| // be called and the objects will be left uninitialized. |
| // |
| // With both of these approaches, we must define and explicitly call an init |
| // routine that uses placement new to create the objects and overwrite the |
| // uninitialized placeholders. |
| // |
| // This is not completely portable, but is what we have for now without |
| // changing how a lot of code accesses these global objects. |
| |
| #ifdef SKIP_STATIC_CONSTRUCTORS_ON_MSVC |
| // - Assume that all includes of this header want ALL of their static |
| // initializers ignored. This is currently the case. This means that if |
| // a .cc includes this header (or it somehow gets included), all static |
| // initializers after the include will not be executed. |
| // - We do this with a pragma, so that all of the static initializer pointers |
| // go into our own section, and the CRT won't call them. Eventually it would |
| // be nice if the section was discarded, because we don't want the pointers. |
| // See: http://msdn.microsoft.com/en-us/library/7977wcck(VS.80).aspx |
| #pragma warning(disable:4075) |
| #pragma init_seg(".unwantedstaticinits") |
| #endif |
| |
| #ifndef SKIP_STATIC_CONSTRUCTORS_ON_GCC |
| // Define an global in the normal way. |
| #define DEFINE_GLOBAL(type, name, ...) \ |
| const type name; |
| |
| #else |
| // Define an correctly-sized array of pointers to avoid static initialization. |
| // Use an array of pointers instead of an array of char in case there is some alignment issue. |
| #define DEFINE_GLOBAL(type, name, ...) \ |
| void * name[(sizeof(type) + sizeof(void *) - 1) / sizeof(void *)]; |
| #endif |
| |
| #endif // StaticConstructors_h |
