search.c

T-kernel 的extension源代码

/*
 *----------------------------------------------------------------------
 *    T-Kernel / Standard Extension
 *
 *    Copyright (C) 2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel / Standard Extension is distributed 
 *      under the T-License for T-Kernel / Standard Extension.
 *----------------------------------------------------------------------
 *
 *    Version:   1.00.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/11.
 *
 *----------------------------------------------------------------------
 */

/*
 *	@(#)search.c (libdl) 
 *
 *	DLL support library
 *	Shared object search
 */

#include "libdl.h"
#include <tcode.h>


#define TM_DEBUG(s)

/*
 * Standard library file
 */
LOCAL TC STDLIB[] = {	TC_FDLM, TK_S, TK_Y, TK_S,
			TC_FDLM, TK_l, TK_i, TK_b, TNULL };

/*
 * Search of the shared object file 
 *	Return the "LINK" to "ink" after searching of the library file(shared object file) specified at "path".
 *	Search the location specified at "mode" when "path" is the relative path specification.
 *
 *	mode = [DL_BASE] | [DL_WORK] | [DL_PROC] | [DL_STDLIB]
 *
 *	DL_BASE   (0x08)  The file specified at "lnk" 
 *	DL_WORK   (0x04)  Current working file
 *	DL_PROC   (0x02)  The invoking process program file
 *	DL_STDLIB (0x01)  Standard library file  /SYS/lib
 *
 *	Search in this order (DL_BASE -> DL_STDLIB)
 *
 *	Also, search is done according to the file name only. No concern with the content of the file.
 *	Return "E_NOEXS" when file is not found.
 */
EXPORT ER tkse_dlsearch( TC *path, LINK *lnk, W mode )
{
static	W	order[] = { DL_BASE, DL_WORK, DL_PROC, DL_STDLIB };
	LINK	slnk;
	W	smode, i;
	ER	err;

	TM_DEBUG("tkse_dlsearch() entry\n");

	if ( path[0] == TC_FDLM ) {
		TM_DEBUG("tkse_dlsearch() 1\n");
		/* Absolute pass specification */
		err = tkse_get_lnk(path, lnk, F_NORM);
		if ( err < E_OK ) {
			goto err_ret;
		}

		return E_OK;
	}

	/* Relative path specification */
		TM_DEBUG("tkse_dlsearch() 2\n");
	err = E_PAR;
	for ( i = 0; i < (W)(sizeof(order)/sizeof(W)); ++i ) {
	

		switch ( mode & order[i] ) {
		  case DL_BASE:		/* Search "lnk" */
			TM_DEBUG("tkse_dlsearch() 3\n");

			slnk = *lnk;
			smode = F_BASED;
			break;

		  case DL_WORK:		/* Search the current working file */
			TM_DEBUG("tkse_dlsearch() 4\n");
			smode = F_NORM;
			break;

		  case DL_PROC:		/* Search the invoking program file */
			TM_DEBUG("tkse_dlsearch() 5\n");
			err = tkse_prc_inf(0, PI_LINK, &slnk, sizeof(slnk));
			if ( err < E_OK ) {
				goto err_ret;
			}
			smode = F_BASED;
			break;

		  case DL_STDLIB:	/* Search the standard library file */
			TM_DEBUG("tkse_dlsearch() 6\n");
			err = tkse_get_lnk(STDLIB, &slnk, F_NORM);
			if ( err < E_OK ) {
				goto err_ret;
			}
			smode = F_BASED;
			break;

		  default:
			TM_DEBUG("tkse_dlsearch() 7\n");
			continue;
		}

		TM_DEBUG("tkse_dlsearch() 8\n");
		TM_DEBUG(path);

		err = tkse_get_lnk(path, &slnk, smode);
		if ( err >= 0 ) {
			break;
		}
	}
	TM_DEBUG("tkse_dlsearch() 9\n");
	if ( err < E_OK ) {
		goto err_ret;
	}
	*lnk = slnk;

	return E_OK;

err_ret:
	DEBUG_PRINT(("tkse_dlsearch err = %d\n", err));
	return err;
}