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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_NATIVE_LIBRARY_H_
#define BASE_NATIVE_LIBRARY_H_
// This file defines a cross-platform "NativeLibrary" type which represents
// a loadable module.
#include <string>
#include "base/base_export.h"
#include "base/files/file_path.h"
#include "base/strings/string_piece.h"
#include "build/build_config.h"
#if defined(OS_WIN)
#include <windows.h>
#elif defined(OS_APPLE)
#import <CoreFoundation/CoreFoundation.h>
#endif // OS_*
namespace base {
#if defined(OS_WIN)
using NativeLibrary = HMODULE;
#elif defined(OS_APPLE)
enum NativeLibraryType {
BUNDLE,
DYNAMIC_LIB
};
enum NativeLibraryObjCStatus {
OBJC_UNKNOWN,
OBJC_PRESENT,
OBJC_NOT_PRESENT,
};
struct NativeLibraryStruct {
NativeLibraryType type;
CFBundleRefNum bundle_resource_ref;
NativeLibraryObjCStatus objc_status;
union {
CFBundleRef bundle;
void* dylib;
};
};
using NativeLibrary = NativeLibraryStruct*;
#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
using NativeLibrary = void*;
#endif // OS_*
struct BASE_EXPORT NativeLibraryLoadError {
#if defined(OS_WIN)
NativeLibraryLoadError() : code(0) {}
#endif // OS_WIN
// Returns a string representation of the load error.
std::string ToString() const;
#if defined(OS_WIN)
DWORD code;
#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
std::string message;
#endif // OS_WIN
};
struct BASE_EXPORT NativeLibraryOptions {
NativeLibraryOptions() = default;
NativeLibraryOptions(const NativeLibraryOptions& options) = default;
// If |true|, a loaded library is required to prefer local symbol resolution
// before considering global symbols. Note that this is already the default
// behavior on most systems. Setting this to |false| does not guarantee the
// inverse, i.e., it does not force a preference for global symbols over local
// ones.
bool prefer_own_symbols = false;
};
// Loads a native library from disk. Release it with UnloadNativeLibrary when
// you're done. Returns NULL on failure.
// If |error| is not NULL, it may be filled in on load error.
BASE_EXPORT NativeLibrary LoadNativeLibrary(const FilePath& library_path,
NativeLibraryLoadError* error);
#if defined(OS_WIN)
// Loads a native library from the system directory using the appropriate flags.
// The function first checks to see if the library is already loaded and will
// get a handle if so. This method results in a lock that may block the calling
// thread.
BASE_EXPORT NativeLibrary
LoadSystemLibrary(FilePath::StringPieceType name,
NativeLibraryLoadError* error = nullptr);
// Gets the module handle for the specified system library and pins it to
// ensure it never gets unloaded. If the module is not loaded, it will first
// call LoadSystemLibrary to load it. If the module cannot be pinned, this
// method returns null and includes the error. This method results in a lock
// that may block the calling thread.
BASE_EXPORT NativeLibrary
PinSystemLibrary(FilePath::StringPieceType name,
NativeLibraryLoadError* error = nullptr);
#endif
// Loads a native library from disk. Release it with UnloadNativeLibrary when
// you're done. Returns NULL on failure.
// If |error| is not NULL, it may be filled in on load error.
BASE_EXPORT NativeLibrary LoadNativeLibraryWithOptions(
const FilePath& library_path,
const NativeLibraryOptions& options,
NativeLibraryLoadError* error);
// Unloads a native library.
BASE_EXPORT void UnloadNativeLibrary(NativeLibrary library);
// Gets a function pointer from a native library.
BASE_EXPORT void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
StringPiece name);
// Returns the full platform-specific name for a native library. |name| must be
// ASCII. This is also the default name for the output of a gn |shared_library|
// target. See tools/gn/docs/reference.md#shared_library.
// For example for "mylib", it returns:
// - "mylib.dll" on Windows
// - "libmylib.so" on Linux
// - "libmylib.dylib" on Mac
BASE_EXPORT std::string GetNativeLibraryName(StringPiece name);
// Returns the full platform-specific name for a gn |loadable_module| target.
// See tools/gn/docs/reference.md#loadable_module
// The returned name is the same as GetNativeLibraryName() on all platforms
// except for Mac where for "mylib" it returns "mylib.so".
BASE_EXPORT std::string GetLoadableModuleName(StringPiece name);
} // namespace base
#endif // BASE_NATIVE_LIBRARY_H_