/*
* tclLoadDl.c --
*
* This procedure provides a version of the TclLoadFile that works with
* the "dlopen" and "dlsym" library procedures for dynamic loading.
*
* Copyright (c) 1995-1997 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 "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_LOCAL flag doesn't exist on
* some platforms; if it doesn't exist, set it to 0 so it has no effect.
* See [Bug #3216070]
*/
#ifndef RTLD_NOW
# define RTLD_NOW 1
#endif
#ifndef RTLD_LOCAL
# define RTLD_LOCAL 0
#endif
/*
* Static procedures defined within this file.
*/
static void * FindSymbol(Tcl_Interp *interp,
Tcl_LoadHandle loadHandle, const char *symbol);
static void UnloadFile(Tcl_LoadHandle loadHandle);
/*
*---------------------------------------------------------------------------
*
* 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)
{
void *handle;
Tcl_LoadHandle newHandle;
const char *native;
int dlopenflags = 0;
/*
* 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);
/*
* Use (RTLD_NOW|RTLD_LOCAL) as default, see [Bug #3216070]
*/
if (flags & TCL_LOAD_GLOBAL) {
dlopenflags |= RTLD_GLOBAL;
} else {
dlopenflags |= RTLD_LOCAL;
}
if (flags & TCL_LOAD_LAZY) {
dlopenflags |= RTLD_LAZY;
} else {
dlopenflags |= RTLD_NOW;
}
handle = dlopen(native, dlopenflags);
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;
const char *fileName = Tcl_GetString(pathPtr);
native = Tcl_UtfToExternalDString(NULL, fileName, -1, &ds);
/*
* Use (RTLD_NOW|RTLD_LOCAL) as default, see [Bug #3216070]
*/
handle = dlopen(native, dlopenflags);
Tcl_DStringFree(&ds);
}
if (handle == NULL) {
/*
* Write the string to a variable first to work around a compiler bug
* in the Sun Forte 6 compiler. [Bug 1503729]
*/
const char *errorStr = dlerror();
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"couldn't load file \"%s\": %s",
Tcl_GetString(pathPtr), errorStr));
return TCL_ERROR;
}
newHandle = ckalloc(sizeof(*newHandle));
newHandle->clientData = handle;
newHandle->findSymbolProcPtr = &FindSymbol;
newHandle->unloadFileProcPtr = &UnloadFile;
*unloadProcPtr = &UnloadFile;
*loadHandle = newHandle;
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* 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, /* Place to put error messages. */
Tcl_LoadHandle loadHandle, /* Value from TcpDlopen(). */
const char *symbol) /* Symbol to look up. */
{
const char *native; /* Name of the library to be loaded, in
* system encoding */
Tcl_DString newName, ds; /* Buffers for converting the name to
* system encoding and prepending an
* underscore*/
void *handle = (void *) loadHandle->clientData;
/* Native handle to the loaded library */
void *proc; /* Address corresponding to the resolved
* symbol */
/*
* 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.
*/
native = Tcl_UtfToExternalDString(NULL, symbol, -1, &ds);
proc = dlsym(handle, native); /* INTL: Native. */
if (proc == NULL) {
Tcl_DStringInit(&newName);
TclDStringAppendLiteral(&newName, "_");
native = Tcl_DStringAppend(&newName, native, -1);
proc = dlsym(handle, native); /* INTL: Native. */
Tcl_DStringFree(&newName);
}
Tcl_DStringFree(&ds);
if (proc == NULL && interp != NULL) {
const char *errorStr = dlerror();
if (!errorStr) {
errorStr = "unknown";
}
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"cannot find symbol \"%s\": %s", symbol, errorStr));
Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LOAD_SYMBOL", symbol,
NULL);
}
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. */
{
void *handle = loadHandle->clientData;
dlclose(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:
*/