/* * tclIndexObj.c -- * * This file implements objects of type "index". This object type * is used to lookup a keyword in a table of valid values and cache * the index of the matching entry. * * Copyright (c) 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: tclIndexObj.c,v 1.16.2.5 2006/04/06 18:57:24 dgp Exp $ */ #include "tclInt.h" #include "tclPort.h" /* * Prototypes for procedures defined later in this file: */ static int SetIndexFromAny _ANSI_ARGS_((Tcl_Interp *interp, Tcl_Obj *objPtr)); static void UpdateStringOfIndex _ANSI_ARGS_((Tcl_Obj *objPtr)); static void DupIndex _ANSI_ARGS_((Tcl_Obj *srcPtr, Tcl_Obj *dupPtr)); static void FreeIndex _ANSI_ARGS_((Tcl_Obj *objPtr)); /* * The structure below defines the index Tcl object type by means of * procedures that can be invoked by generic object code. */ Tcl_ObjType tclIndexType = { "index", /* name */ FreeIndex, /* freeIntRepProc */ DupIndex, /* dupIntRepProc */ UpdateStringOfIndex, /* updateStringProc */ SetIndexFromAny /* setFromAnyProc */ }; /* * The definition of the internal representation of the "index" * object; The internalRep.otherValuePtr field of an object of "index" * type will be a pointer to one of these structures. * * Keep this structure declaration in sync with tclTestObj.c */ typedef struct { VOID *tablePtr; /* Pointer to the table of strings */ int offset; /* Offset between table entries */ int index; /* Selected index into table. */ } IndexRep; /* * The following macros greatly simplify moving through a table... */ #define STRING_AT(table, offset, index) \ (*((CONST char * CONST *)(((char *)(table)) + ((offset) * (index))))) #define NEXT_ENTRY(table, offset) \ (&(STRING_AT(table, offset, 1))) #define EXPAND_OF(indexRep) \ STRING_AT((indexRep)->tablePtr, (indexRep)->offset, (indexRep)->index) /* *---------------------------------------------------------------------- * * Tcl_GetIndexFromObj -- * * This procedure looks up an object's value in a table of strings * and returns the index of the matching string, if any. * * Results: * * If the value of objPtr is identical to or a unique abbreviation * for one of the entries in objPtr, then the return value is * TCL_OK and the index of the matching entry is stored at * *indexPtr. If there isn't a proper match, then TCL_ERROR is * returned and an error message is left in interp's result (unless * interp is NULL). The msg argument is used in the error * message; for example, if msg has the value "option" then the * error message will say something flag 'bad option "foo": must be * ...' * * Side effects: * The result of the lookup is cached as the internal rep of * objPtr, so that repeated lookups can be done quickly. * *---------------------------------------------------------------------- */ int Tcl_GetIndexFromObj(interp, objPtr, tablePtr, msg, flags, indexPtr) Tcl_Interp *interp; /* Used for error reporting if not NULL. */ Tcl_Obj *objPtr; /* Object containing the string to lookup. */ CONST char **tablePtr; /* Array of strings to compare against the * value of objPtr; last entry must be NULL * and there must not be duplicate entries. */ CONST char *msg; /* Identifying word to use in error messages. */ int flags; /* 0 or TCL_EXACT */ int *indexPtr; /* Place to store resulting integer index. */ { /* * See if there is a valid cached result from a previous lookup * (doing the check here saves the overhead of calling * Tcl_GetIndexFromObjStruct in the common case where the result * is cached). */ if (objPtr->typePtr == &tclIndexType) { IndexRep *indexRep = (IndexRep *) objPtr->internalRep.otherValuePtr; /* * Here's hoping we don't get hit by unfortunate packing * constraints on odd platforms like a Cray PVP... */ if (indexRep->tablePtr == (VOID *)tablePtr && indexRep->offset == sizeof(char *)) { *indexPtr = indexRep->index; return TCL_OK; } } return Tcl_GetIndexFromObjStruct(interp, objPtr, tablePtr, sizeof(char *), msg, flags, indexPtr); } /* *---------------------------------------------------------------------- * * Tcl_GetIndexFromObjStruct -- * * This procedure looks up an object's value given a starting * string and an offset for the amount of space between strings. * This is useful when the strings are embedded in some other * kind of array. * * Results: * * If the value of objPtr is identical to or a unique abbreviation * for one of the entries in objPtr, then the return value is * TCL_OK and the index of the matching entry is stored at * *indexPtr. If there isn't a proper match, then TCL_ERROR is * returned and an error message is left in interp's result (unless * interp is NULL). The msg argument is used in the error * message; for example, if msg has the value "option" then the * error message will say something flag 'bad option "foo": must be * ...' * * Side effects: * The result of the lookup is cached as the internal rep of * objPtr, so that repeated lookups can be done quickly. * *---------------------------------------------------------------------- */ int Tcl_GetIndexFromObjStruct(interp, objPtr, tablePtr, offset, msg, flags, indexPtr) Tcl_Interp *interp; /* Used for error reporting if not NULL. */ Tcl_Obj *objPtr; /* Object containing the string to lookup. */ CONST VOID *tablePtr; /* The first string in the table. The second * string will be at this address plus the * offset, the third plus the offset again, * etc. The last entry must be NULL * and there must not be duplicate entries. */ int offset; /* The number of bytes between entries */ CONST char *msg; /* Identifying word to use in error messages. */ int flags; /* 0 or TCL_EXACT */ int *indexPtr; /* Place to store resulting integer index. */ { int index, i, numAbbrev; char *key, *p1; CONST char *p2; CONST char * CONST *entryPtr; Tcl_Obj *resultPtr; IndexRep *indexRep; /* * See if there is a valid cached result from a previous lookup. */ if (objPtr->typePtr == &tclIndexType) { indexRep = (IndexRep *) objPtr->internalRep.otherValuePtr; if (indexRep->tablePtr==tablePtr && indexRep->offset==offset) { *indexPtr = indexRep->index; return TCL_OK; } } /* * Lookup the value of the object in the table. Accept unique * abbreviations unless TCL_EXACT is set in flags. */ key = TclGetString(objPtr); index = -1; numAbbrev = 0; /* * Scan the table looking for one of: * - An exact match (always preferred) * - A single abbreviation (allowed depending on flags) * - Several abbreviations (never allowed, but overridden by exact match) */ for (entryPtr = tablePtr, i = 0; *entryPtr != NULL; entryPtr = NEXT_ENTRY(entryPtr, offset), i++) { for (p1 = key, p2 = *entryPtr; *p1 == *p2; p1++, p2++) { if (*p1 == '\0') { index = i; goto done; } } if (*p1 == '\0') { /* * The value is an abbreviation for this entry. Continue * checking other entries to make sure it's unique. If we * get more than one unique abbreviation, keep searching to * see if there is an exact match, but remember the number * of unique abbreviations and don't allow either. */ numAbbrev++; index = i; } } /* * Check if we were instructed to disallow abbreviations. */ if ((flags & TCL_EXACT) || (key[0] == '\0') || (numAbbrev != 1)) { goto error; } done: /* * Cache the found representation. Note that we want to avoid * allocating a new internal-rep if at all possible since that is * potentially a slow operation. */ if (objPtr->typePtr == &tclIndexType) { indexRep = (IndexRep *) objPtr->internalRep.otherValuePtr; } else { if ((objPtr->typePtr != NULL) && (objPtr->typePtr->freeIntRepProc != NULL)) { objPtr->typePtr->freeIntRepProc(objPtr); } indexRep = (IndexRep *) ckalloc(sizeof(IndexRep)); objPtr->internalRep.otherValuePtr = (VOID *) indexRep; objPtr->typePtr = &tclIndexType; } indexRep->tablePtr = (VOID*) tablePtr; indexRep->offset = offset; indexRep->index = index; *indexPtr = index; return TCL_OK; error: if (interp != NULL) { /* * Produce a fancy error message. */ int count; TclNewObj(resultPtr); Tcl_SetObjResult(interp, resultPtr); Tcl_AppendStringsToObj(resultPtr, (numAbbrev > 1) && !(flags & TCL_EXACT) ? "ambiguous " : "bad ", msg, " \"", key, "\": must be ", STRING_AT(tablePtr,offset,0), (char*)NULL); for (entryPtr = NEXT_ENTRY(tablePtr, offset), count = 0; *entryPtr != NULL; entryPtr = NEXT_ENTRY(entryPtr, offset), count++) { if (*NEXT_ENTRY(entryPtr, offset) == NULL) { Tcl_AppendStringsToObj(resultPtr, (count > 0) ? ", or " : " or ", *entryPtr, (char *) NULL); } else { Tcl_AppendStringsToObj(resultPtr, ", ", *entryPtr, (char *) NULL); } } } return TCL_ERROR; } /* *---------------------------------------------------------------------- * * SetIndexFromAny -- * * This procedure is called to convert a Tcl object to index * internal form. However, this doesn't make sense (need to have a * table of keywords in order to do the conversion) so the * procedure always generates an error. * * Results: * The return value is always TCL_ERROR, and an error message is * left in interp's result if interp isn't NULL. * * Side effects: * None. * *---------------------------------------------------------------------- */ static int SetIndexFromAny(interp, objPtr) Tcl_Interp *interp; /* Used for error reporting if not NULL. */ register Tcl_Obj *objPtr; /* The object to convert. */ { Tcl_AppendToObj(Tcl_GetObjResult(interp), "can't convert value to index except via Tcl_GetIndexFromObj API", -1); return TCL_ERROR; } /* *---------------------------------------------------------------------- * * UpdateStringOfIndex -- * * This procedure is called to convert a Tcl object from index * internal form to its string form. No abbreviation is ever * generated. * * Results: * None. * * Side effects: * The string representation of the object is updated. * *---------------------------------------------------------------------- */ static void UpdateStringOfIndex(objPtr) Tcl_Obj *objPtr; { IndexRep *indexRep = (IndexRep *) objPtr->internalRep.otherValuePtr; register char *buf; register unsigned len; register CONST char *indexStr = EXPAND_OF(indexRep); len = strlen(indexStr); buf = (char *) ckalloc(len + 1); memcpy(buf, indexStr, len+1); objPtr->bytes = buf; objPtr->length = len; } /* *---------------------------------------------------------------------- * * DupIndex -- * * This procedure is called to copy the internal rep of an index * Tcl object from to another object. * * Results: * None. * * Side effects: * The internal representation of the target object is updated * and the type is set. * *---------------------------------------------------------------------- */ static void DupIndex(srcPtr, dupPtr) Tcl_Obj *srcPtr, *dupPtr; { IndexRep *srcIndexRep = (IndexRep *) srcPtr->internalRep.otherValuePtr; IndexRep *dupIndexRep = (IndexRep *) ckalloc(sizeof(IndexRep)); memcpy(dupIndexRep, srcIndexRep, sizeof(IndexRep)); dupPtr->internalRep.otherValuePtr = (VOID *) dupIndexRep; dupPtr->typePtr = &tclIndexType; } /* *---------------------------------------------------------------------- * * FreeIndex -- * * This procedure is called to delete the internal rep of an index * Tcl object. * * Results: * None. * * Side effects: * The internal representation of the target object is deleted. * *---------------------------------------------------------------------- */ static void FreeIndex(objPtr) Tcl_Obj *objPtr; { ckfree((char *) objPtr->internalRep.otherValuePtr); } /* *---------------------------------------------------------------------- * * Tcl_WrongNumArgs -- * * This procedure generates a "wrong # args" error message in an * interpreter. It is used as a utility function by many command * procedures. * * Results: * None. * * Side effects: * An error message is generated in interp's result object to * indicate that a command was invoked with the wrong number of * arguments. The message has the form * wrong # args: should be "foo bar additional stuff" * where "foo" and "bar" are the initial objects in objv (objc * determines how many of these are printed) and "additional stuff" * is the contents of the message argument. * *---------------------------------------------------------------------- */ void Tcl_WrongNumArgs(interp, objc, objv, message) Tcl_Interp *interp; /* Current interpreter. */ int objc; /* Number of arguments to print * from objv. */ Tcl_Obj *CONST objv[]; /* Initial argument objects, which * should be included in the error * message. */ CONST char *message; /* Error message to print after the * leading objects in objv. The * message may be NULL. */ { Tcl_Obj *objPtr; int i; register IndexRep *indexRep; TclNewObj(objPtr); Tcl_SetObjResult(interp, objPtr); Tcl_AppendToObj(objPtr, "wrong # args: should be \"", -1); for (i = 0; i < objc; i++) { /* * If the object is an index type use the index table which allows * for the correct error message even if the subcommand was * abbreviated. Otherwise, just use the string rep. */ if (objv[i]->typePtr == &tclIndexType) { indexRep = (IndexRep *) objv[i]->internalRep.otherValuePtr; Tcl_AppendStringsToObj(objPtr, EXPAND_OF(indexRep), (char *) NULL); } else { Tcl_AppendStringsToObj(objPtr, Tcl_GetString(objv[i]), (char *) NULL); } /* * Append a space character (" ") if there is more text to follow * (either another element from objv, or the message string). */ if ((i < (objc - 1)) || message) { Tcl_AppendStringsToObj(objPtr, " ", (char *) NULL); } } if (message) { Tcl_AppendStringsToObj(objPtr, message, (char *) NULL); } Tcl_AppendStringsToObj(objPtr, "\"", (char *) NULL); }