gecko/nsprpub/pr/include/prlink.h
2008-06-06 08:36:51 -04:00

261 lines
9.5 KiB
C

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape Portable Runtime (NSPR).
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef prlink_h___
#define prlink_h___
/*
** API to static and dynamic linking.
*/
#include "prtypes.h"
PR_BEGIN_EXTERN_C
typedef struct PRLibrary PRLibrary;
typedef struct PRStaticLinkTable {
const char *name;
void (*fp)();
} PRStaticLinkTable;
/*
** Change the default library path to the given string. The string is
** copied. This call will fail if it runs out of memory.
**
** The string provided as 'path' is copied. The caller can do whatever is
** convenient with the argument when the function is complete.
*/
NSPR_API(PRStatus) PR_SetLibraryPath(const char *path);
/*
** Return a character string which contains the path used to search for
** dynamically loadable libraries.
**
** The returned value is basically a copy of a PR_SetLibraryPath().
** The storage is allocated by the runtime and becomes the responsibilty
** of the caller.
*/
NSPR_API(char*) PR_GetLibraryPath(void);
/*
** Given a directory name "dir" and a library name "lib" construct a full
** path name that will refer to the actual dynamically loaded
** library. This does not test for existance of said file, it just
** constructs the full filename. The name constructed is system dependent
** and prepared for PR_LoadLibrary. The result must be free'd when the
** caller is done with it.
**
** The storage for the result is allocated by the runtime and becomes the
** responsibility of the caller.
*/
NSPR_API(char*) PR_GetLibraryName(const char *dir, const char *lib);
/*
**
** Free the memory allocated, for the caller, by PR_GetLibraryName
*/
NSPR_API(void) PR_FreeLibraryName(char *mem);
/*
** Given a library "name" try to load the library. The argument "name"
** is a machine-dependent name for the library, such as the full pathname
** returned by PR_GetLibraryName. If the library is already loaded,
** this function will avoid loading the library twice.
**
** If the library is loaded successfully, then a pointer to the PRLibrary
** structure representing the library is returned. Otherwise, NULL is
** returned.
**
** This increments the reference count of the library.
*/
NSPR_API(PRLibrary*) PR_LoadLibrary(const char *name);
/*
** Each operating system has its preferred way of specifying
** a file in the file system. Most operating systems use
** a pathname. Mac OS, on the other hand, uses the FSSpec
** structure to specify a file. PRLibSpec allows NSPR clients
** to use the type of file specification that is most efficient
** for a particular platform.
**
** On some operating systems such as Mac OS, a shared library may
** contain code fragments that can be individually loaded.
** PRLibSpec also allows NSPR clients to identify a code fragment
** in a library, if code fragments are supported by the OS.
** A code fragment can be specified by name or by an integer index.
**
** Right now PRLibSpec supports four types of library specification:
** a pathname in the native character encoding, a Mac code fragment
** by name, a Mac code fragment by index, and a UTF-16 pathname.
*/
typedef enum PRLibSpecType {
PR_LibSpec_Pathname,
PR_LibSpec_MacNamedFragment, /* obsolete (for Mac OS Classic) */
PR_LibSpec_MacIndexedFragment, /* obsolete (for Mac OS Classic) */
PR_LibSpec_PathnameU /* supported only on Win32 */
} PRLibSpecType;
struct FSSpec; /* Mac OS FSSpec */
typedef struct PRLibSpec {
PRLibSpecType type;
union {
/* if type is PR_LibSpec_Pathname */
const char *pathname;
/* if type is PR_LibSpec_MacNamedFragment */
struct {
const struct FSSpec *fsspec;
const char *name;
} mac_named_fragment; /* obsolete (for Mac OS Classic) */
/* if type is PR_LibSpec_MacIndexedFragment */
struct {
const struct FSSpec *fsspec;
PRUint32 index;
} mac_indexed_fragment; /* obsolete (for Mac OS Classic) */
/* if type is PR_LibSpec_PathnameU */
const PRUnichar *pathname_u; /* supported only on Win32 */
} value;
} PRLibSpec;
/*
** The following bit flags may be or'd together and passed
** as the 'flags' argument to PR_LoadLibraryWithFlags.
** Flags not supported by the underlying OS are ignored.
*/
#define PR_LD_LAZY 0x1 /* equivalent to RTLD_LAZY on Unix */
#define PR_LD_NOW 0x2 /* equivalent to RTLD_NOW on Unix */
#define PR_LD_GLOBAL 0x4 /* equivalent to RTLD_GLOBAL on Unix */
#define PR_LD_LOCAL 0x8 /* equivalent to RTLD_LOCAL on Unix */
/* 0x8000 reserved for NSPR internal use */
/*
** Load the specified library, in the manner specified by 'flags'.
*/
NSPR_API(PRLibrary *)
PR_LoadLibraryWithFlags(
PRLibSpec libSpec, /* the shared library */
PRIntn flags /* flags that affect the loading */
);
/*
** Unload a previously loaded library. If the library was a static
** library then the static link table will no longer be referenced. The
** associated PRLibrary object is freed.
**
** PR_FAILURE is returned if the library cannot be unloaded.
**
** This function decrements the reference count of the library.
*/
NSPR_API(PRStatus) PR_UnloadLibrary(PRLibrary *lib);
/*
** Given the name of a procedure, return the address of the function that
** implements the procedure, or NULL if no such function can be
** found. This does not find symbols in the main program (the ".exe");
** use PR_LoadStaticLibrary to register symbols in the main program.
**
** This function does not modify the reference count of the library.
*/
NSPR_API(void*) PR_FindSymbol(PRLibrary *lib, const char *name);
/*
** Similar to PR_FindSymbol, except that the return value is a pointer to
** a function, and not a pointer to void. Casting between a data pointer
** and a function pointer is not portable according to the C standard.
** Any function pointer can be cast to any other function pointer.
**
** This function does not modify the reference count of the library.
*/
typedef void (*PRFuncPtr)();
NSPR_API(PRFuncPtr) PR_FindFunctionSymbol(PRLibrary *lib, const char *name);
/*
** Finds a symbol in one of the currently loaded libraries. Given the
** name of a procedure, return the address of the function that
** implements the procedure, and return the library that contains that
** symbol, or NULL if no such function can be found. This does not find
** symbols in the main program (the ".exe"); use PR_AddStaticLibrary to
** register symbols in the main program.
**
** This increments the reference count of the library.
*/
NSPR_API(void*) PR_FindSymbolAndLibrary(const char *name,
PRLibrary* *lib);
/*
** Similar to PR_FindSymbolAndLibrary, except that the return value is
** a pointer to a function, and not a pointer to void. Casting between a
** data pointer and a function pointer is not portable according to the C
** standard. Any function pointer can be cast to any other function pointer.
**
** This increments the reference count of the library.
*/
NSPR_API(PRFuncPtr) PR_FindFunctionSymbolAndLibrary(const char *name,
PRLibrary* *lib);
/*
** Register a static link table with the runtime under the name
** "name". The symbols present in the static link table will be made
** available to PR_FindSymbol. If "name" is null then the symbols will be
** made available to the library which represents the executable. The
** tables are not copied.
**
** Returns the library object if successful, null otherwise.
**
** This increments the reference count of the library.
*/
NSPR_API(PRLibrary*) PR_LoadStaticLibrary(
const char *name, const PRStaticLinkTable *table);
/*
** Return the pathname of the file that the library "name" was loaded
** from. "addr" is the address of a function defined in the library.
**
** The caller is responsible for freeing the result with PR_Free.
*/
NSPR_API(char *) PR_GetLibraryFilePathname(const char *name, PRFuncPtr addr);
PR_END_EXTERN_C
#endif /* prlink_h___ */