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Diffstat (limited to 'unix/tclLoadShl.c')
-rw-r--r-- | unix/tclLoadShl.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/unix/tclLoadShl.c b/unix/tclLoadShl.c new file mode 100644 index 0000000..4be3d7b --- /dev/null +++ b/unix/tclLoadShl.c @@ -0,0 +1,224 @@ +/* + * 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: + */ |