freebsd-dev/contrib/tcl/unix/tclLoadDl.c
1997-07-25 19:27:55 +00:00

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/*
* tclLoadDl.c --
*
* This procedure provides a version of the TclLoadFile that
* works with the "dlopen" and "dlsym" library procedures for
* dynamic loading.
*
* Copyright (c) 1995 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tclLoadDl.c 1.8 96/12/03 16:57:00
*/
#include "tclInt.h"
#ifdef NO_DLFCN_H
# include "../compat/dlfcn.h"
#else
# include <dlfcn.h>
#endif
/*
* In some systems, like SunOS 4.1.3, the RTLD_NOW flag isn't defined
* and this argument to dlopen must always be 1. The RTLD_GLOBAL
* flag is needed on some systems (e.g. SCO and UnixWare) but doesn't
* exist on others; if it doesn't exist, set it to 0 so it has no effect.
*/
#ifndef RTLD_NOW
# define RTLD_NOW 1
#endif
#ifndef RTLD_GLOBAL
# define RTLD_GLOBAL 0
#endif
/*
*----------------------------------------------------------------------
*
* TclLoadFile --
*
* 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 interp->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
TclLoadFile(interp, fileName, sym1, sym2, proc1Ptr, proc2Ptr)
Tcl_Interp *interp; /* Used for error reporting. */
char *fileName; /* Name of the file containing the desired
* code. */
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. */
{
VOID *handle;
Tcl_DString newName;
handle = dlopen(fileName, RTLD_NOW | RTLD_GLOBAL);
if (handle == NULL) {
Tcl_AppendResult(interp, "couldn't load file \"", fileName,
"\": ", dlerror(), (char *) NULL);
return TCL_ERROR;
}
/*
* Some platforms still add an underscore to the beginning of symbol
* names. If we can't find a name without an underscore, try again
* with the underscore.
*/
*proc1Ptr = (Tcl_PackageInitProc *) dlsym(handle, (char *) sym1);
if (*proc1Ptr == NULL) {
Tcl_DStringInit(&newName);
Tcl_DStringAppend(&newName, "_", 1);
Tcl_DStringAppend(&newName, sym1, -1);
*proc1Ptr = (Tcl_PackageInitProc *) dlsym(handle,
Tcl_DStringValue(&newName));
Tcl_DStringFree(&newName);
}
*proc2Ptr = (Tcl_PackageInitProc *) dlsym(handle, (char *) sym2);
if (*proc2Ptr == NULL) {
Tcl_DStringInit(&newName);
Tcl_DStringAppend(&newName, "_", 1);
Tcl_DStringAppend(&newName, sym2, -1);
*proc2Ptr = (Tcl_PackageInitProc *) dlsym(handle,
Tcl_DStringValue(&newName));
Tcl_DStringFree(&newName);
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* 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;
}