summaryrefslogtreecommitdiffstats
path: root/unix/tclLoadDld.c
blob: faa68ce4a74a3e363a9bf8ba7d0b3df68ff81ce9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/* 
 * tclLoadDld.c --
 *
 *	This procedure provides a version of the TclLoadFile that
 *	works with the "dld_link" and "dld_get_func" library procedures
 *	for dynamic loading.  It has been tested on Linux 1.1.95 and
 *	dld-3.2.7.  This file probably isn't needed anymore, since it
 *	makes more sense to use "dl_open" etc.
 *
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclLoadDld.c,v 1.6 2001/09/28 01:21:53 dgp Exp $
 */

#include "tclInt.h"
#include "dld.h"

/*
 * In some systems, like SunOS 4.1.3, the RTLD_NOW flag isn't defined
 * and this argument to dlopen must always be 1.
 */

#ifndef RTLD_NOW
#   define RTLD_NOW 1
#endif

/*
 *----------------------------------------------------------------------
 *
 * TclpLoadFile --
 *
 *	Dynamically loads a binary code file into memory and returns
 *	the addresses of two procedures within that file, if they
 *	are defined.
 *
 * Results:
 *	A standard Tcl completion code.  If an error occurs, an error
 *	message is left in the interp's result.  *proc1Ptr and *proc2Ptr
 *	are filled in with the addresses of the symbols given by
 *	*sym1 and *sym2, or NULL if those symbols can't be found.
 *
 * Side effects:
 *	New code suddenly appears in memory.
 *
 *----------------------------------------------------------------------
 */

int
TclpLoadFile(interp, pathPtr, sym1, sym2, proc1Ptr, proc2Ptr, 
	     clientDataPtr, unloadProcPtr)
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tcl_Obj *pathPtr;		/* Name of the file containing the desired
				 * code. */
    CONST char *sym1, *sym2;	/* Names of two procedures to look up in
				 * the file's symbol table. */
    Tcl_PackageInitProc **proc1Ptr, **proc2Ptr;
				/* Where to return the addresses corresponding
				 * to sym1 and sym2. */
    ClientData *clientDataPtr;	/* Filled with token for dynamically loaded
				 * file which will be passed back to 
				 * (*unloadProcPtr)() to unload the file. */
    Tcl_FSUnloadFileProc **unloadProcPtr;	
				/* Filled with address of Tcl_FSUnloadFileProc
				 * function which should be used for
				 * this file. */
{
    static int firstTime = 1;
    int returnCode;
    char *fileName = Tcl_GetString(pathPtr);
    
    /*
     *  The dld package needs to know the pathname to the tcl binary.
     *  If that's not know, return an error.
     */

    if (firstTime) {
	if (tclExecutableName == NULL) {
	    Tcl_SetResult(interp,
		    "don't know name of application binary file, so can't initialize dynamic loader",
		    TCL_STATIC);
	    return TCL_ERROR;
	}
	returnCode = dld_init(tclExecutableName);
	if (returnCode != 0) {
	    Tcl_AppendResult(interp,
		    "initialization failed for dynamic loader: ",
		    dld_strerror(returnCode), (char *) NULL);
	    return TCL_ERROR;
	}
	firstTime = 0;
    }

    if ((returnCode = dld_link(Tcl_GetString(pathPtr)) != 0) {
	Tcl_AppendResult(interp, "couldn't load file \"", 
			 Tcl_GetString(pathPtr),
			 "\": ", dld_strerror(returnCode), (char *) NULL);
	return TCL_ERROR;
    }
    *proc1Ptr = (Tcl_PackageInitProc *) dld_get_func(sym1);
    *proc2Ptr = (Tcl_PackageInitProc *) dld_get_func(sym2);
    *clientDataPtr = strcpy(
	    (char *) ckalloc((unsigned) (strlen(fileName) + 1)), fileName);
    *unloadProcPtr = &TclpUnloadFile;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpUnloadFile --
 *
 *	Unloads a dynamically loaded binary code file from memory.
 *	Code pointers in the formerly loaded file are no longer valid
 *	after calling this function.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Code removed from memory.
 *
 *----------------------------------------------------------------------
 */

void
TclpUnloadFile(clientData)
    ClientData clientData;	/* ClientData returned by a previous call
				 * to TclpLoadFile().  The clientData is 
				 * a token that represents the loaded 
				 * file. */
{
    char *fileName;

    handle = (char *) clientData;
    dld_unlink_by_file(handle, 0);
    ckfree(handle);
}

/*
 *----------------------------------------------------------------------
 *
 * TclGuessPackageName --
 *
 *	If the "load" command is invoked without providing a package
 *	name, this procedure is invoked to try to figure it out.
 *
 * Results:
 *	Always returns 0 to indicate that we couldn't figure out a
 *	package name;  generic code will then try to guess the package
 *	from the file name.  A return value of 1 would have meant that
 *	we figured out the package name and put it in bufPtr.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclGuessPackageName(fileName, bufPtr)
    char *fileName;		/* Name of file containing package (already
				 * translated to local form if needed). */
    Tcl_DString *bufPtr;	/* Initialized empty dstring.  Append
				 * package name to this if possible. */
{
    return 0;
}