summaryrefslogtreecommitdiffstats
path: root/unix/tclLoadShl.c
blob: 4be3d7b2cedcfa0f04f7bce54f699fdb567e1720 (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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
/*
 * tclLoadShl.c --
 *
 *	This procedure provides a version of the TclLoadFile that works with
 *	the "shl_load" and "shl_findsym" library procedures for dynamic
 *	loading (e.g. for HP machines).
 *
 * 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.
 */

#include <dl.h>
#include "tclInt.h"

/*
 * Static functions defined within this file.
 */

static void *		FindSymbol(Tcl_Interp *interp,
			    Tcl_LoadHandle loadHandle, const char *symbol);
static void		UnloadFile(Tcl_LoadHandle handle);

/*
 *----------------------------------------------------------------------
 *
 * TclpDlopen --
 *
 *	Dynamically loads a binary code file into memory and returns a handle
 *	to the new code.
 *
 * Results:
 *	A standard Tcl completion code.  If an error occurs, an error message
 *	is left in the interp's result.
 *
 * Side effects:
 *	New code suddenly appears in memory.
 *
 *----------------------------------------------------------------------
 */

int
TclpDlopen(
    Tcl_Interp *interp,		/* Used for error reporting. */
    Tcl_Obj *pathPtr,		/* Name of the file containing the desired
				 * code (UTF-8). */
    Tcl_LoadHandle *loadHandle,	/* 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. */
    int flags)
{
    shl_t handle;
    Tcl_LoadHandle newHandle;
    const char *native;
    char *fileName = Tcl_GetString(pathPtr);

    /*
     * The flags below used to be BIND_IMMEDIATE; they were changed at the
     * suggestion of Wolfgang Kechel (wolfgang@prs.de): "This enables
     * verbosity for missing symbols when loading a shared lib and allows to
     * load libtk8.0.sl into tclsh8.0 without problems.  In general, this
     * delays resolving symbols until they are actually needed.  Shared libs
     * do no longer need all libraries linked in when they are build."
     */

    /*
     * First try the full path the user gave us.  This is particularly
     * important if the cwd is inside a vfs, and we are trying to load using a
     * relative path.
     */

    native = Tcl_FSGetNativePath(pathPtr);
    handle = shl_load(native, BIND_DEFERRED|BIND_VERBOSE, 0L);

    if (handle == NULL) {
	/*
	 * Let the OS loader examine the binary search path for whatever
	 * string the user gave us which hopefully refers to a file on the
	 * binary path.
	 */

	Tcl_DString ds;

	native = Tcl_UtfToExternalDString(NULL, fileName, -1, &ds);
	handle = shl_load(native, BIND_DEFERRED|BIND_VERBOSE|DYNAMIC_PATH, 0L);
	Tcl_DStringFree(&ds);
    }

    if (handle == NULL) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't load file \"%s\": %s",
		fileName, Tcl_PosixError(interp)));
	return TCL_ERROR;
    }
    newHandle = ckalloc(sizeof(*newHandle));
    newHandle->clientData = handle;
    newHandle->findSymbolProcPtr = &FindSymbol;
    newHandle->unloadFileProcPtr = *unloadProcPtr = &UnloadFile;
    *loadHandle = newHandle;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FindSymbol --
 *
 *	Looks up a symbol, by name, through a handle associated with a
 *	previously loaded piece of code (shared library).
 *
 * Results:
 *	Returns a pointer to the function associated with 'symbol' if it is
 *	found.  Otherwise returns NULL and may leave an error message in the
 *	interp's result.
 *
 *----------------------------------------------------------------------
 */

static void*
FindSymbol(
    Tcl_Interp *interp,
    Tcl_LoadHandle loadHandle,
    const char *symbol)
{
    Tcl_DString newName;
    Tcl_PackageInitProc *proc = NULL;
    shl_t handle = (shl_t) loadHandle->clientData;

    /*
     * Some versions of the HP system software still use "_" at the beginning
     * of exported symbols while others don't; try both forms of each name.
     */

    if (shl_findsym(&handle, symbol, (short) TYPE_PROCEDURE,
	    (void *) &proc) != 0) {
	Tcl_DStringInit(&newName);
	TclDStringAppendLiteral(&newName, "_");
	Tcl_DStringAppend(&newName, symbol, -1);
	if (shl_findsym(&handle, Tcl_DStringValue(&newName),
		(short) TYPE_PROCEDURE, (void *) &proc) != 0) {
	    proc = NULL;
	}
	Tcl_DStringFree(&newName);
    }
    if (proc == NULL && interp != NULL) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"cannot find symbol \"%s\": %s",
		symbol, Tcl_PosixError(interp)));
    }
    return proc;
}

/*
 *----------------------------------------------------------------------
 *
 * UnloadFile --
 *
 *	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.
 *
 *----------------------------------------------------------------------
 */

static void
UnloadFile(
    Tcl_LoadHandle loadHandle)	/* loadHandle returned by a previous call to
				 * TclpDlopen(). The loadHandle is a token
				 * that represents the loaded file. */
{
    shl_t handle = (shl_t) loadHandle->clientData;

    shl_unload(handle);
    ckfree(loadHandle);
}

/*
 *----------------------------------------------------------------------
 *
 * 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(
    const 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;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */