michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef prlink_h___
michael@0: #define prlink_h___
michael@0: 
michael@0: /*
michael@0: ** API to static and dynamic linking.
michael@0: */
michael@0: #include "prtypes.h"
michael@0: 
michael@0: PR_BEGIN_EXTERN_C
michael@0: 
michael@0: typedef struct PRLibrary PRLibrary;
michael@0: 
michael@0: typedef struct PRStaticLinkTable {
michael@0:     const char *name;
michael@0:     void (*fp)(void);
michael@0: } PRStaticLinkTable;
michael@0: 
michael@0: /*
michael@0: ** Change the default library path to the given string. The string is
michael@0: ** copied. This call will fail if it runs out of memory.
michael@0: **
michael@0: ** The string provided as 'path' is copied. The caller can do whatever is
michael@0: ** convenient with the argument when the function is complete.
michael@0: */
michael@0: NSPR_API(PRStatus) PR_SetLibraryPath(const char *path);
michael@0: 
michael@0: /*
michael@0: ** Return a character string which contains the path used to search for
michael@0: ** dynamically loadable libraries.
michael@0: **
michael@0: ** The returned value is basically a copy of a PR_SetLibraryPath().
michael@0: ** The storage is allocated by the runtime and becomes the responsibilty
michael@0: ** of the caller.
michael@0: */
michael@0: NSPR_API(char*) PR_GetLibraryPath(void);
michael@0: 
michael@0: /*
michael@0: ** Given a directory name "dir" and a library name "lib" construct a full
michael@0: ** path name that will refer to the actual dynamically loaded
michael@0: ** library. This does not test for existance of said file, it just
michael@0: ** constructs the full filename. The name constructed is system dependent
michael@0: ** and prepared for PR_LoadLibrary. The result must be free'd when the
michael@0: ** caller is done with it.
michael@0: **
michael@0: ** The storage for the result is allocated by the runtime and becomes the
michael@0: ** responsibility of the caller.
michael@0: */
michael@0: NSPR_API(char*) PR_GetLibraryName(const char *dir, const char *lib);
michael@0: 
michael@0: /*
michael@0: **
michael@0: ** Free the memory allocated, for the caller, by PR_GetLibraryName
michael@0: */
michael@0: NSPR_API(void) PR_FreeLibraryName(char *mem);
michael@0: 
michael@0: /*
michael@0: ** Given a library "name" try to load the library. The argument "name"
michael@0: ** is a machine-dependent name for the library, such as the full pathname
michael@0: ** returned by PR_GetLibraryName.  If the library is already loaded,
michael@0: ** this function will avoid loading the library twice.
michael@0: **
michael@0: ** If the library is loaded successfully, then a pointer to the PRLibrary
michael@0: ** structure representing the library is returned.  Otherwise, NULL is
michael@0: ** returned.
michael@0: **
michael@0: ** This increments the reference count of the library.
michael@0: */
michael@0: NSPR_API(PRLibrary*) PR_LoadLibrary(const char *name);
michael@0: 
michael@0: /*
michael@0: ** Each operating system has its preferred way of specifying
michael@0: ** a file in the file system.  Most operating systems use
michael@0: ** a pathname.  Mac OS Classic, on the other hand, uses the FSSpec
michael@0: ** structure to specify a file. PRLibSpec allows NSPR clients
michael@0: ** to use the type of file specification that is most efficient
michael@0: ** for a particular platform.
michael@0: **
michael@0: ** On some operating systems such as Mac OS Classic, a shared library
michael@0: ** may contain code fragments that can be individually loaded.
michael@0: ** PRLibSpec also allows NSPR clients to identify a code fragment
michael@0: ** in a library, if code fragments are supported by the OS.
michael@0: ** A code fragment can be specified by name or by an integer index.
michael@0: **
michael@0: ** Right now PRLibSpec supports four types of library specification:
michael@0: ** a pathname in the native character encoding, a Mac code fragment
michael@0: ** by name, a Mac code fragment by index, and a UTF-16 pathname.
michael@0: */
michael@0: 
michael@0: typedef enum PRLibSpecType {
michael@0:     PR_LibSpec_Pathname,
michael@0:     PR_LibSpec_MacNamedFragment,   /* obsolete (for Mac OS Classic) */
michael@0:     PR_LibSpec_MacIndexedFragment, /* obsolete (for Mac OS Classic) */
michael@0:     PR_LibSpec_PathnameU           /* supported only on Win32 */ 
michael@0: } PRLibSpecType;
michael@0: 
michael@0: struct FSSpec; /* Mac OS Classic FSSpec */
michael@0: 
michael@0: typedef struct PRLibSpec {
michael@0:     PRLibSpecType type;
michael@0:     union {
michael@0:         /* if type is PR_LibSpec_Pathname */
michael@0:         const char *pathname;
michael@0: 
michael@0:         /* if type is PR_LibSpec_MacNamedFragment */
michael@0:         struct {
michael@0:             const struct FSSpec *fsspec;
michael@0:             const char *name;
michael@0:         } mac_named_fragment;      /* obsolete (for Mac OS Classic) */
michael@0: 
michael@0:         /* if type is PR_LibSpec_MacIndexedFragment */
michael@0:         struct {
michael@0:             const struct FSSpec *fsspec;
michael@0:             PRUint32 index;
michael@0:         } mac_indexed_fragment;    /* obsolete (for Mac OS Classic) */
michael@0: 
michael@0:         /* if type is PR_LibSpec_PathnameU */
michael@0:         const PRUnichar *pathname_u; /* supported only on Win32 */
michael@0:     } value;
michael@0: } PRLibSpec;
michael@0: 
michael@0: /*
michael@0: ** The following bit flags may be or'd together and passed
michael@0: ** as the 'flags' argument to PR_LoadLibraryWithFlags.
michael@0: ** Flags not supported by the underlying OS are ignored.
michael@0: */
michael@0: 
michael@0: #define PR_LD_LAZY   0x1  /* equivalent to RTLD_LAZY on Unix */
michael@0: #define PR_LD_NOW    0x2  /* equivalent to RTLD_NOW on Unix */
michael@0: #define PR_LD_GLOBAL 0x4  /* equivalent to RTLD_GLOBAL on Unix */
michael@0: #define PR_LD_LOCAL  0x8  /* equivalent to RTLD_LOCAL on Unix */
michael@0: /* The following is equivalent to LOAD_WITH_ALTERED_SEARCH_PATH on Windows */
michael@0: #define PR_LD_ALT_SEARCH_PATH  0x10  
michael@0: /*                0x8000     reserved for NSPR internal use */
michael@0: 
michael@0: /*
michael@0: ** Load the specified library, in the manner specified by 'flags'.
michael@0: */
michael@0: 
michael@0: NSPR_API(PRLibrary *)
michael@0: PR_LoadLibraryWithFlags(
michael@0:     PRLibSpec libSpec,    /* the shared library */
michael@0:     PRIntn flags          /* flags that affect the loading */
michael@0: );
michael@0: 
michael@0: /*
michael@0: ** Unload a previously loaded library. If the library was a static
michael@0: ** library then the static link table will no longer be referenced. The
michael@0: ** associated PRLibrary object is freed.
michael@0: **
michael@0: ** PR_FAILURE is returned if the library cannot be unloaded.
michael@0: **
michael@0: ** This function decrements the reference count of the library.
michael@0: */
michael@0: NSPR_API(PRStatus) PR_UnloadLibrary(PRLibrary *lib);
michael@0: 
michael@0: /*
michael@0: ** Given the name of a procedure, return the address of the function that
michael@0: ** implements the procedure, or NULL if no such function can be
michael@0: ** found. This does not find symbols in the main program (the ".exe");
michael@0: ** use PR_LoadStaticLibrary to register symbols in the main program.
michael@0: **
michael@0: ** This function does not modify the reference count of the library.
michael@0: */
michael@0: NSPR_API(void*) PR_FindSymbol(PRLibrary *lib, const char *name);
michael@0: 
michael@0: /*
michael@0: ** Similar to PR_FindSymbol, except that the return value is a pointer to
michael@0: ** a function, and not a pointer to void. Casting between a data pointer
michael@0: ** and a function pointer is not portable according to the C standard.
michael@0: ** Any function pointer can be cast to any other function pointer.
michael@0: **
michael@0: ** This function does not modify the reference count of the library.
michael@0: */
michael@0: typedef void (*PRFuncPtr)(void);
michael@0: NSPR_API(PRFuncPtr) PR_FindFunctionSymbol(PRLibrary *lib, const char *name);
michael@0: 
michael@0: /*
michael@0: ** Finds a symbol in one of the currently loaded libraries. Given the
michael@0: ** name of a procedure, return the address of the function that
michael@0: ** implements the procedure, and return the library that contains that
michael@0: ** symbol, or NULL if no such function can be found. This does not find
michael@0: ** symbols in the main program (the ".exe"); use PR_AddStaticLibrary to
michael@0: ** register symbols in the main program.  
michael@0: **
michael@0: ** This increments the reference count of the library.
michael@0: */
michael@0: NSPR_API(void*) PR_FindSymbolAndLibrary(const char *name,
michael@0: 						      PRLibrary* *lib);
michael@0: 
michael@0: /*
michael@0: ** Similar to PR_FindSymbolAndLibrary, except that the return value is
michael@0: ** a pointer to a function, and not a pointer to void. Casting between a
michael@0: ** data pointer and a function pointer is not portable according to the C
michael@0: ** standard. Any function pointer can be cast to any other function pointer.
michael@0: **
michael@0: ** This increments the reference count of the library.
michael@0: */
michael@0: NSPR_API(PRFuncPtr) PR_FindFunctionSymbolAndLibrary(const char *name,
michael@0: 						      PRLibrary* *lib);
michael@0: 
michael@0: /*
michael@0: ** Register a static link table with the runtime under the name
michael@0: ** "name". The symbols present in the static link table will be made
michael@0: ** available to PR_FindSymbol. If "name" is null then the symbols will be
michael@0: ** made available to the library which represents the executable. The
michael@0: ** tables are not copied.
michael@0: **
michael@0: ** Returns the library object if successful, null otherwise.
michael@0: **
michael@0: ** This increments the reference count of the library.
michael@0: */
michael@0: NSPR_API(PRLibrary*) PR_LoadStaticLibrary(
michael@0:     const char *name, const PRStaticLinkTable *table);
michael@0: 
michael@0: /*
michael@0: ** Return the pathname of the file that the library "name" was loaded
michael@0: ** from. "addr" is the address of a function defined in the library.
michael@0: **
michael@0: ** The caller is responsible for freeing the result with PR_Free.
michael@0: */
michael@0: NSPR_API(char *) PR_GetLibraryFilePathname(const char *name, PRFuncPtr addr);
michael@0: 
michael@0: PR_END_EXTERN_C
michael@0: 
michael@0: #endif /* prlink_h___ */