Module.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
#ifndef MODULE_H
#define MODULE_H
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/utilities/utility.h"
 
#include <config.h>
 
#ifndef __cplusplus
#include <stdbool.h>
#endif
 
typedef bool (*ModuleEntry)();
typedef void (*ModuleExit)();
 
#define MODULE_TAG 0xdeadbaba
 
struct ModuleInfo {
  uint32_t tag;
  const char* name;
  ModuleEntry entry;
  ModuleExit exit;
  const char** dependencies;
  const char** opt_dependencies;
  // False pins the module image for the kernel lifetime, even if entry fails.
  bool unloadable;
  // False rejects explicit unload while still permitting failure and shutdown cleanup.
  bool runtimeUnloadable;
} PACKED;
 
#if STATIC_DRIVERS
 
extern ModuleInfo* g_StaticDrivers[128];
extern size_t g_StaticDriverN;
 
class StaticDriverModule {
 public:
  StaticDriverModule(const char* name, ModuleEntry entry, ModuleExit exit, const char** deps,
                     bool unloadable, const char** opt_deps = nullptr)
      : StaticDriverModule(name, entry, exit, deps, unloadable, opt_deps, unloadable) {}
 
  StaticDriverModule(const char* name, ModuleEntry entry, ModuleExit exit, const char** deps,
                     bool unloadable, const char** opt_deps, bool runtimeUnloadable) {
    info.tag = MODULE_TAG;
    info.name = name;
    info.entry = entry;
    info.exit = exit;
    info.dependencies = deps;
    info.opt_dependencies = opt_deps;
    info.unloadable = unloadable;
    info.runtimeUnloadable = runtimeUnloadable;
    g_StaticDrivers[g_StaticDriverN++] = &info;
  }
 
  ModuleInfo info;
};
 
class StaticDriverOptionalDependencies {
 public:
  StaticDriverOptionalDependencies(StaticDriverModule& module, const char** dependencies) {
    module.info.opt_dependencies = dependencies;
  }
};
 
#define MODULE_INFO2_FLAGS(unloadable, runtimeUnloadable, name, entry, exit, ...)        \
  static const char* __mod_deps[] = {__VA_ARGS__, 0};                                    \
  static StaticDriverModule __module(name, entry, exit, __mod_deps, unloadable, nullptr, \
                                     runtimeUnloadable);
 
#define MODULE_INFO2(name, entry, exit, ...) \
  MODULE_INFO2_FLAGS(true, true, name, entry, exit, __VA_ARGS__)
 
#define MODULE_OPTIONAL_DEPENDS(...)                      \
  static const char* __mod_opt_deps[] = {__VA_ARGS__, 0}; \
  static StaticDriverOptionalDependencies __module_opt_dependencies(__module, __mod_opt_deps)
 
#else
 
#define MODULE_NAME(x) const char* g_pModuleName EXPORTED_PUBLIC SECTION(".modinfo") USED = x
#define MODULE_ENTRY(x) ModuleEntry g_pModuleEntry EXPORTED_PUBLIC SECTION(".modinfo") USED = x
#define MODULE_EXIT(x) ModuleExit g_pModuleExit EXPORTED_PUBLIC SECTION(".modinfo") USED = x
#define MODULE_UNLOADABLE(x) bool g_bModuleUnloadable EXPORTED_PUBLIC SECTION(".modinfo") USED = x
#define MODULE_RUNTIME_UNLOADABLE(x) \
  bool g_bModuleRuntimeUnloadable EXPORTED_PUBLIC SECTION(".modinfo") USED = x
#define MODULE_DEPENDS(...) \
  const char* g_pDepends[] EXPORTED_PUBLIC SECTION(".modinfo") USED = {__VA_ARGS__, 0}
#define MODULE_DEPENDS2(...) \
  const char* g_pDepends[] EXPORTED_PUBLIC SECTION(".modinfo") USED = {__VA_ARGS__}
 
#define MODULE_OPTIONAL_DEPENDS(...) \
  const char* g_pOptionalDepends[] EXPORTED_PUBLIC SECTION(".modinfo") USED = {__VA_ARGS__, 0}
 
#define MODULE_INFO2_FLAGS(unloadable, runtimeUnloadable, name, entry, exit, ...) \
  MODULE_NAME(name);                                                              \
  MODULE_ENTRY(entry);                                                            \
  MODULE_EXIT(exit);                                                              \
  MODULE_UNLOADABLE(unloadable);                                                  \
  MODULE_RUNTIME_UNLOADABLE(runtimeUnloadable);                                   \
  MODULE_DEPENDS2(__VA_ARGS__);
 
#define MODULE_INFO2(name, entry, exit, ...) \
  MODULE_INFO2_FLAGS(true, true, name, entry, exit, __VA_ARGS__)
 
extern const char* g_pModuleName;
extern ModuleEntry g_pModuleEntry;
extern ModuleExit g_pModuleExit;
extern bool g_bModuleUnloadable;
extern bool g_bModuleRuntimeUnloadable;
extern const char* g_pDepends[];
extern const char* g_pOptionalDepends[];
 
#endif
 
#define MODULE_INFO(...) MODULE_INFO2(__VA_ARGS__, 0)
#define MODULE_INFO_NON_UNLOADABLE(...) MODULE_INFO2_FLAGS(false, false, __VA_ARGS__, 0)
#define MODULE_INFO_RUNTIME_PINNED(...) MODULE_INFO2_FLAGS(true, false, __VA_ARGS__, 0)
 
#endif