| //===-- Shared/APIHelpers.h - helpers for external APIs --*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // The header contains helper functions to make interactions with external APIs |
| // such as CUDA or level zero easier |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_COMMON_APIHELPERS_H |
| #define OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_COMMON_APIHELPERS_H |
| |
| #include "DLWrap.h" |
| |
| #define API_HELPER_STRINGIFY_INNER(x) #x |
| #define API_HELPER_STRINGIFY(x) API_HELPER_STRINGIFY_INNER(x) |
| |
| // Macro to mark external symbol as weak, so linker will be okay |
| // if the symbol is missing. For direct linking only available on Linux, we need |
| // to check if linker could find the symbol. For symbols loaded using dlsym we |
| // call name##_loaded function. The name##_loaded function will be nullptr if |
| // external library was linked directly. |
| // _Pragma("weak name") retroactively downgrades any prior strong declaration |
| // (e.g. from a vendor header included before this macro) to weak. |
| #define API_HELPER_OPTIONAL(return_type, name, ...) \ |
| _Pragma(API_HELPER_STRINGIFY(weak name)) namespace dlwrap { \ |
| bool name##_loaded() __attribute__((weak)); \ |
| } \ |
| extern "C" return_type name(__VA_ARGS__) __attribute__((weak)); \ |
| template <> inline bool api_helper::canCall<name>() { \ |
| if (name == nullptr) \ |
| /* Not loaded weak symbol, only possible on Linux */ \ |
| return false; \ |
| /* If symbol wasn't dlwrapped, i.e name##_loaded == nullptr and is not \ |
| * nullptr, it means the symbol was linked directly, so we can call it */ \ |
| if (dlwrap::name##_loaded == nullptr) \ |
| return true; \ |
| /* Symbol is not nullptr and it was dlwrapped, all symbols on Windows go \ |
| * here*/ \ |
| return dlwrap::name##_loaded(); \ |
| } |
| |
| namespace api_helper { |
| |
| // Default template specialization for extra safety |
| template <auto Fn> bool canCall() { |
| static_assert(sizeof(decltype(Fn) *) == 0, |
| "api_helper::canCall() should only be called on symbols " |
| "decorated with API_HELPER_OPTIONAL!"); |
| } |
| |
| } // namespace api_helper |
| |
| #endif // OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_COMMON_APIHELPERS_H |
