prlink.c

Netscape NSPR库源码

    PR_EnterMonitor(pr_linker_lock);
    result = pr_UnlockedFindLibrary(name);
    PR_ExitMonitor(pr_linker_lock);
    return result;
}


#ifdef XP_MAC

static PRLibrary*
pr_Mac_LoadNamedFragment(const FSSpec *fileSpec, const char* fragmentName)
{
	PRLibrary*					newLib = NULL;
	PRLibrary* 					result;
	FSSpec							resolvedSpec = *fileSpec;
	CFragConnectionID		connectionID = 0;
	Boolean							isFolder, wasAlias;
	OSErr								err = noErr;
	
	if (!_pr_initialized) _PR_ImplicitInitialization();

	/* See if library is already loaded */
	PR_EnterMonitor(pr_linker_lock);
  
	result = pr_UnlockedFindLibrary(fragmentName);
	if (result != NULL) goto unlock;

	newLib = PR_NEWZAP(PRLibrary);
	if (newLib == NULL) goto unlock;
	newLib->staticTable = NULL;


	/* Resolve an alias if this was one */
	err = ResolveAliasFile(&resolvedSpec, true, &isFolder, &wasAlias);
	if (err != noErr)
		goto unlock;

  if (isFolder)
  {
  	err = fnfErr;
  	goto unlock;
  }
    
	/* Finally, try to load the library */
	err = NSLoadNamedFragment(&resolvedSpec, fragmentName, &connectionID);
	if (err != noErr)
		goto unlock;

  newLib->name = strdup(fragmentName);
  newLib->dlh = connectionID;
  newLib->next = pr_loadmap;
  pr_loadmap = newLib;

  result = newLib;    /* success */
  PR_LOG(_pr_linker_lm, PR_LOG_MIN, ("Loaded library %s (load lib)", newLib->name));

unlock:
	if (result == NULL) {
		if (newLib != NULL)
			PR_DELETE(newLib);
		PR_SetError(PR_LOAD_LIBRARY_ERROR, _MD_ERRNO());
		DLLErrorInternal(_MD_ERRNO());  /* sets error text */
	}
	PR_ExitMonitor(pr_linker_lock);
	return result;
}


static PRLibrary*
pr_Mac_LoadIndexedFragment(const FSSpec *fileSpec, PRUint32 fragIndex)
{
	PRLibrary*					newLib = NULL;
	PRLibrary* 					result;
	FSSpec							resolvedSpec = *fileSpec;
	char*								fragmentName = NULL;
	UInt32              fragOffset, fragLength;                
	CFragConnectionID		connectionID = 0;
	Boolean							isFolder, wasAlias;
	OSErr								err = noErr;

	if (!_pr_initialized) _PR_ImplicitInitialization();

	/* See if library is already loaded */
	PR_EnterMonitor(pr_linker_lock);

	/* Resolve an alias if this was one */
	err = ResolveAliasFile(&resolvedSpec, true, &isFolder, &wasAlias);
	if (err != noErr)
		goto unlock;

  if (isFolder)
  {
  	err = fnfErr;
  	goto unlock;
  }
    err = GetIndexedFragmentOffsets(&resolvedSpec, fragIndex, &fragOffset, &fragLength, &fragmentName);
  if (err != noErr) goto unlock;
  
	result = pr_UnlockedFindLibrary(fragmentName);
	free(fragmentName);
	fragmentName = NULL;
	if (result != NULL) goto unlock;

	newLib = PR_NEWZAP(PRLibrary);
	if (newLib == NULL) goto unlock;
	newLib->staticTable = NULL;
    
	/* Finally, try to load the library */
	err = NSLoadIndexedFragment(&resolvedSpec, fragIndex, &fragmentName, &connectionID);
	if (err != noErr) {
		PR_DELETE(newLib);
		goto unlock;
	}

  newLib->name = fragmentName;			/* was malloced in NSLoadIndexedFragment */
  newLib->dlh = connectionID;
  newLib->next = pr_loadmap;
  pr_loadmap = newLib;

  result = newLib;    /* success */
  PR_LOG(_pr_linker_lm, PR_LOG_MIN, ("Loaded library %s (load lib)", newLib->name));

unlock:
	if (result == NULL) {
		if (newLib != NULL)
			PR_DELETE(newLib);
		PR_SetError(PR_LOAD_LIBRARY_ERROR, _MD_ERRNO());
		DLLErrorInternal(_MD_ERRNO());  /* sets error text */
	}
	PR_ExitMonitor(pr_linker_lock);
	return result;
}


#endif

/*
** Unload a shared library which was loaded via PR_LoadLibrary
*/
PR_IMPLEMENT(PRStatus) 
PR_UnloadLibrary(PRLibrary *lib)
{
    int result = 0;
    PRStatus status = PR_SUCCESS;

    if ((lib == 0) || (lib->refCount <= 0)) {
        PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
        return PR_FAILURE;
    }

    PR_EnterMonitor(pr_linker_lock);
    if (--lib->refCount > 0) {
    PR_LOG(_pr_linker_lm, PR_LOG_MIN,
           ("%s decr => %d",
        lib->name, lib->refCount));
    goto done;
    }

#ifdef XP_BEOS
    if(((image_id)lib->stub_dlh) == B_ERROR)
        unload_add_on( (image_id) lib->dlh );
    else
        unload_add_on( (image_id) lib->stub_dlh);
#endif

#ifdef XP_UNIX
#ifdef HAVE_DLL
#ifdef USE_DLFCN
    result = dlclose(lib->dlh);
#elif defined(USE_HPSHL)
    result = shl_unload(lib->dlh);
#elif defined(USE_MACH_DYLD)
    result = NSUnLinkModule(lib->dlh, FALSE);
#else
#error Configuration error
#endif
#endif /* HAVE_DLL */
#endif /* XP_UNIX */
#ifdef XP_PC
    if (lib->dlh) {
        FreeLibrary((HINSTANCE)(lib->dlh));
        lib->dlh = (HINSTANCE)NULL;
    }
#endif  /* XP_PC */

#if defined(XP_MAC) && TARGET_RT_MAC_CFM
    /* Close the connection */
#if TARGET_CARBON
    if (lib->bundle)
        CFRelease(lib->bundle);
    else
#endif
    CloseConnection(&(lib->dlh));
#endif

    /* unlink from library search list */
    if (pr_loadmap == lib)
        pr_loadmap = pr_loadmap->next;
    else if (pr_loadmap != NULL) {
        PRLibrary* prev = pr_loadmap;
        PRLibrary* next = pr_loadmap->next;
        while (next != NULL) {
            if (next == lib) {
                prev->next = next->next;
                goto freeLib;
            }
            prev = next;
            next = next->next;
        }
        /*
         * fail (the library is not on the _pr_loadmap list),
         * but don't wipe out an error from dlclose/shl_unload.
         */
        PR_ASSERT(!"_pr_loadmap and lib->refCount inconsistent");
        if (result == 0) {
            PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
            status = PR_FAILURE;
        }
    }
    /*
     * We free the PRLibrary structure whether dlclose/shl_unload
     * succeeds or not.
     */

  freeLib:
    PR_LOG(_pr_linker_lm, PR_LOG_MIN, ("Unloaded library %s", lib->name));
    free(lib->name);
    lib->name = NULL;
    PR_DELETE(lib);
    if (result == -1) {
        PR_SetError(PR_UNLOAD_LIBRARY_ERROR, _MD_ERRNO());
        DLLErrorInternal(_MD_ERRNO());
        status = PR_FAILURE;
    }

done:
    PR_ExitMonitor(pr_linker_lock);
    return status;
}

static void* 
pr_FindSymbolInLib(PRLibrary *lm, const char *name)
{
    void *f = NULL;

    if (lm->staticTable != NULL) {
    const PRStaticLinkTable* tp;
    for (tp = lm->staticTable; tp->name; tp++) {
        if (strcmp(name, tp->name) == 0) {
        return (void*) tp->fp;
        }
    }
        /* 
        ** If the symbol was not found in the static table then check if
        ** the symbol was exported in the DLL... Win16 only!!
        */
#if !defined(WIN16) && !defined(XP_BEOS)
        PR_SetError(PR_FIND_SYMBOL_ERROR, 0);
        return (void*)NULL;
#endif
    }
    
#ifdef XP_OS2
    DosQueryProcAddr(lm->dlh, 0, (PSZ) name, (PFN *) &f);
#endif  /* XP_OS2 */

#if defined(WIN32) || defined(WIN16)
    f = GetProcAddress(lm->dlh, name);
#endif  /* WIN32 || WIN16 */

#ifdef XP_MAC
#if TARGET_CARBON
    if (lm->bundle)
    {
        CFStringRef nameRef = CFStringCreateWithCString(NULL, name, kCFStringEncodingASCII);
        if (nameRef) {
            f = CFBundleGetFunctionPointerForName(lm->bundle, nameRef);
            CFRelease(nameRef);
        }
    }
    else
#endif
    {
        Ptr                 symAddr;
        CFragSymbolClass    symClass;
        Str255              pName;
            
        PStrFromCStr(name, pName);    
        
        f = (NSFindSymbol(lm->dlh, pName, &symAddr, &symClass) == noErr) ? symAddr : NULL;
        
        if (f == NULL && strcmp(name, "main") == 0) f = lm->main;
    }
#endif /* XP_MAC */

#ifdef XP_BEOS
    if( B_NO_ERROR != get_image_symbol( (image_id)lm->dlh, name, B_SYMBOL_TYPE_TEXT, &f ) ) {
        f = NULL;
    }
#endif

#ifdef XP_UNIX
#ifdef HAVE_DLL
#ifdef USE_DLFCN
    f = dlsym(lm->dlh, name);
#elif defined(USE_HPSHL)
    if (shl_findsym(&lm->dlh, name, TYPE_PROCEDURE, &f) == -1) {
        f = NULL;
    }
#elif defined(USE_MACH_DYLD)
    {
        NSSymbol symbol;
        symbol = NSLookupSymbolInModule(lm->dlh, name);
        if (symbol != NULL)
            f = NSAddressOfSymbol(symbol);
        else
            f = NULL;
    }
#endif
#endif /* HAVE_DLL */
#endif /* XP_UNIX */
    if (f == NULL) {
        PR_SetError(PR_FIND_SYMBOL_ERROR, _MD_ERRNO());
        DLLErrorInternal(_MD_ERRNO());
    }
    return f;
}

/*
** Called by class loader to resolve missing native's
*/
PR_IMPLEMENT(void*) 
PR_FindSymbol(PRLibrary *lib, const char *raw_name)
{
    void *f = NULL;
#if defined(NEED_LEADING_UNDERSCORE)
    char *name;
#else
    const char *name;
#endif
    /*
    ** Mangle the raw symbol name in any way that is platform specific.
    */
#if defined(NEED_LEADING_UNDERSCORE)
    /* Need a leading _ */
    name = PR_smprintf("_%s", raw_name);
#elif defined(AIX)
    /*
    ** AIX with the normal linker put's a "." in front of the symbol
    ** name.  When use "svcc" and "svld" then the "." disappears. Go
    ** figure.
    */
    name = raw_name;
#else
    name = raw_name;
#endif

    PR_EnterMonitor(pr_linker_lock);
    PR_ASSERT(lib != NULL);
    f = pr_FindSymbolInLib(lib, name);

#if defined(NEED_LEADING_UNDERSCORE)
    PR_smprintf_free(name);
#endif

    PR_ExitMonitor(pr_linker_lock);
    return f;
}

/*
** Return the address of the function 'raw_name' in the library 'lib'
*/
PR_IMPLEMENT(PRFuncPtr) 
PR_FindFunctionSymbol(PRLibrary *lib, const char *raw_name)
{
    return ((PRFuncPtr) PR_FindSymbol(lib, raw_name));
}

PR_IMPLEMENT(void*) 
PR_FindSymbolAndLibrary(const char *raw_name, PRLibrary* *lib)
{
    void *f = NULL;
#if defined(NEED_LEADING_UNDERSCORE)
    char *name;
#else
    const char *name;
#endif
    PRLibrary* lm;

    if (!_pr_initialized) _PR_ImplicitInitialization();
    /*
    ** Mangle the raw symbol name in any way that is platform specific.
    */
#if defined(NEED_LEADING_UNDERSCORE)
    /* Need a leading _ */
    name = PR_smprintf("_%s", raw_name);
#elif defined(AIX)
    /*
    ** AIX with the normal linker put's a "." in front of the symbol
    ** name.  When use "svcc" and "svld" then the "." disappears. Go
    ** figure.
    */
    name = raw_name;
#else
    name = raw_name;
#endif

    PR_EnterMonitor(pr_linker_lock);

    /* search all libraries */
    for (lm = pr_loadmap; lm != NULL; lm = lm->next) {
        f = pr_FindSymbolInLib(lm, name);
        if (f != NULL) {
            *lib = lm;
            lm->refCount++;
            PR_LOG(_pr_linker_lm, PR_LOG_MIN,
                       ("%s incr => %d (for %s)",
                    lm->name, lm->refCount, name));
            break;
        }
    }
#if defined(NEED_LEADING_UNDERSCORE)
    PR_smprintf_free(name);
#endif

    PR_ExitMonitor(pr_linker_lock);
    return f;
}

PR_IMPLEMENT(PRFuncPtr) 
PR_FindFunctionSymbolAndLibrary(const char *raw_name, PRLibrary* *lib)
{
    return ((PRFuncPtr) PR_FindSymbolAndLibrary(raw_name, lib));
}

/*
** Add a static library to the list of loaded libraries. If LoadLibrary
** is called with the name then we will pretend it was already loaded
*/
PR_IMPLEMENT(PRLibrary*) 
PR_LoadStaticLibrary(const char *name, const PRStaticLinkTable *slt)
{
    PRLibrary *lm=NULL;
    PRLibrary* result = NULL;

    if (!_pr_initialized) _PR_ImplicitInitialization();

    /* See if library is already loaded */
    PR_EnterMonitor(pr_linker_lock);

    /* If the lbrary is already loaded, then add the static table information... */
    result = pr_UnlockedFindLibrary(name);
    if (result != NULL) {
        PR_ASSERT( (result->staticTable == NULL) || (result->staticTable == slt) );
        result->staticTable = slt;
        goto unlock;
    }

    /* Add library to list...Mark it static */
    lm = PR_NEWZAP(PRLibrary);
    if (lm == NULL) goto unlock;

    lm->name = strdup(name);
    lm->refCount    = 1;
    lm->dlh         = pr_exe_loadmap ? pr_exe_loadmap->dlh : 0;
    lm->staticTable = slt;
    lm->next        = pr_loadmap;
    pr_loadmap      = lm;

    result = lm;    /* success */
    PR_ASSERT(lm->refCount == 1);
  unlock:
    PR_LOG(_pr_linker_lm, PR_LOG_MIN, ("Loaded library %s (static lib)", lm->name));
    PR_ExitMonitor(pr_linker_lock);
    return result;
}