/*
* 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 1.38 2007/12/13 15:23:18 dgp Exp $
*/
#include "tclInt.h"
/*
* Prototypes for functions defined later in this file:
*/
static int SetIndexFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr);
static void UpdateStringOfIndex(Tcl_Obj *objPtr);
static void DupIndex(Tcl_Obj *srcPtr, Tcl_Obj *dupPtr);
static void FreeIndex(Tcl_Obj *objPtr);
/*
* The structure below defines the index Tcl object type by means of functions
* that can be invoked by generic object code.
*/
static Tcl_ObjType indexType = {
"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 function 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(
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 == &indexType) {
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 function 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(
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, idx, 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 == &indexType) {
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, idx = 0; *entryPtr != NULL;
entryPtr = NEXT_ENTRY(entryPtr, offset), idx++) {
for (p1 = key, p2 = *entryPtr; *p1 == *p2; p1++, p2++) {
if (*p1 == '\0') {
index = idx;
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 = idx;
}
}
/*
* 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 == &indexType) {
indexRep = objPtr->internalRep.otherValuePtr;
} else {
TclFreeIntRep(objPtr);
indexRep = (IndexRep *) ckalloc(sizeof(IndexRep));
objPtr->internalRep.otherValuePtr = indexRep;
objPtr->typePtr = &indexType;
}
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), 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 ", *entryPtr, NULL);
} else {
Tcl_AppendStringsToObj(resultPtr, ", ", *entryPtr, NULL);
}
}
Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "INDEX", msg, key, NULL);
}
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* SetIndexFromAny --
*
* This function 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 function 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(
Tcl_Interp *interp, /* Used for error reporting if not NULL. */
register Tcl_Obj *objPtr) /* The object to convert. */
{
Tcl_SetObjResult(interp, Tcl_NewStringObj(
"can't convert value to index except via Tcl_GetIndexFromObj API",
-1));
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* UpdateStringOfIndex --
*
* This function 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(
Tcl_Obj *objPtr)
{
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 function 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(
Tcl_Obj *srcPtr,
Tcl_Obj *dupPtr)
{
IndexRep *srcIndexRep = srcPtr->internalRep.otherValuePtr;
IndexRep *dupIndexRep = (IndexRep *) ckalloc(sizeof(IndexRep));
memcpy(dupIndexRep, srcIndexRep, sizeof(IndexRep));
dupPtr->internalRep.otherValuePtr = dupIndexRep;
dupPtr->typePtr = &indexType;
}
/*
*----------------------------------------------------------------------
*
* FreeIndex --
*
* This function 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(
Tcl_Obj *objPtr)
{
ckfree((char *) objPtr->internalRep.otherValuePtr);
}
/*
*----------------------------------------------------------------------
*
* Tcl_WrongNumArgs --
*
* This function generates a "wrong # args" error message in an
* interpreter. It is used as a utility function by many command
* functions, including the function that implements 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.
*
* The message printed is modified somewhat if the command is wrapped
* inside an ensemble. In that case, the error message generated is
* rewritten in such a way that it appears to be generated from the
* user-visible command and not how that command is actually implemented,
* giving a better overall user experience.
*
* Internally, the Tcl core may set the flag INTERP_ALTERNATE_WRONG_ARGS
* in the interpreter to generate complex multi-part messages by calling
* this function repeatedly. This allows the code that knows how to
* handle ensemble-related error messages to be kept here while still
* generating suitable error messages for commands like [read] and
* [socket]. Ideally, this would be done through an extra flags argument,
* but that wouldn't be source-compatible with the existing API and it's
* a fairly rare requirement anyway.
*
*----------------------------------------------------------------------
*/
void
Tcl_WrongNumArgs(
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, len, elemLen, flags;
Interp *iPtr = (Interp *) interp;
const char *elementStr;
/*
* [incr Tcl] does something fairly horrific when generating error
* messages for its ensembles; it passes the whole set of ensemble
* arguments as a list in the first argument. This means that this code
* causes a problem in iTcl if it attempts to correctly quote all
* arguments, which would be the correct thing to do. We work around this
* nasty behaviour for now, and hope that we can remove it all in the
* future...
*/
#ifndef AVOID_HACKS_FOR_ITCL
int isFirst = 1; /* Special flag used to inhibit the treating
* of the first word as a list element so the
* hacky way Itcl generates error messages for
* its ensembles will still work. [Bug
* 1066837] */
# define MAY_QUOTE_WORD (!isFirst)
# define AFTER_FIRST_WORD (isFirst = 0)
#else /* !AVOID_HACKS_FOR_ITCL */
# define MAY_QUOTE_WORD 1
# define AFTER_FIRST_WORD (void) 0
#endif /* AVOID_HACKS_FOR_ITCL */
TclNewObj(objPtr);
if (iPtr->flags & INTERP_ALTERNATE_WRONG_ARGS) {
Tcl_AppendObjToObj(objPtr, Tcl_GetObjResult(interp));
Tcl_AppendToObj(objPtr, " or \"", -1);
} else {
Tcl_AppendToObj(objPtr, "wrong # args: should be \"", -1);
}
/*
* Check to see if we are processing an ensemble implementation, and if so
* rewrite the results in terms of how the ensemble was invoked.
*/
if (iPtr->ensembleRewrite.sourceObjs != NULL) {
int toSkip = iPtr->ensembleRewrite.numInsertedObjs;
int toPrint = iPtr->ensembleRewrite.numRemovedObjs;
Tcl_Obj *const *origObjv = iPtr->ensembleRewrite.sourceObjs;
/*
* We only know how to do rewriting if all the replaced objects are
* actually arguments (in objv) to this function. Otherwise it just
* gets too complicated and we'd be better off just giving a slightly
* confusing error message...
*/
if (objc < toSkip) {
goto addNormalArgumentsToMessage;
}
/*
* Strip out the actual arguments that the ensemble inserted.
*/
objv += toSkip;
objc -= toSkip;
/*
* We assume no object is of index type.
*/
for (i=0 ; i<toPrint ; i++) {
/*
* Add the element, quoting it if necessary.
*/
if (origObjv[i]->typePtr == &indexType) {
register IndexRep *indexRep =
origObjv[i]->internalRep.otherValuePtr;
elementStr = EXPAND_OF(indexRep);
elemLen = strlen(elementStr);
} else if (origObjv[i]->typePtr == &tclEnsembleCmdType) {
register EnsembleCmdRep *ecrPtr =
origObjv[i]->internalRep.otherValuePtr;
elementStr = ecrPtr->fullSubcmdName;
elemLen = strlen(elementStr);
} else {
elementStr = TclGetStringFromObj(origObjv[i], &elemLen);
}
len = Tcl_ScanCountedElement(elementStr, elemLen, &flags);
if (MAY_QUOTE_WORD && len != elemLen) {
char *quotedElementStr = TclStackAlloc(interp, (unsigned)len);
len = Tcl_ConvertCountedElement(elementStr, elemLen,
quotedElementStr, flags);
Tcl_AppendToObj(objPtr, quotedElementStr, len);
TclStackFree(interp, quotedElementStr);
} else {
Tcl_AppendToObj(objPtr, elementStr, elemLen);
}
AFTER_FIRST_WORD;
/*
* Add a space if the word is not the last one (which has a
* moderately complex condition here).
*/
if (i<toPrint-1 || objc!=0 || message!=NULL) {
Tcl_AppendStringsToObj(objPtr, " ", NULL);
}
}
}
/*
* Now add the arguments (other than those rewritten) that the caller took
* from its calling context.
*/
addNormalArgumentsToMessage:
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 == &indexType) {
register IndexRep *indexRep = objv[i]->internalRep.otherValuePtr;
Tcl_AppendStringsToObj(objPtr, EXPAND_OF(indexRep), NULL);
} else if (objv[i]->typePtr == &tclEnsembleCmdType) {
register EnsembleCmdRep *ecrPtr =
objv[i]->internalRep.otherValuePtr;
Tcl_AppendStringsToObj(objPtr, ecrPtr->fullSubcmdName, NULL);
} else {
/*
* Quote the argument if it contains spaces (Bug 942757).
*/
elementStr = TclGetStringFromObj(objv[i], &elemLen);
len = Tcl_ScanCountedElement(elementStr, elemLen, &flags);
if (MAY_QUOTE_WORD && len != elemLen) {
char *quotedElementStr = TclStackAlloc(interp,(unsigned) len);
len = Tcl_ConvertCountedElement(elementStr, elemLen,
quotedElementStr, flags);
Tcl_AppendToObj(objPtr, quotedElementStr, len);
TclStackFree(interp, quotedElementStr);
} else {
Tcl_AppendToObj(objPtr, elementStr, elemLen);
}
}
AFTER_FIRST_WORD;
/*
* 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!=NULL) {
Tcl_AppendStringsToObj(objPtr, " ", NULL);
}
}
/*
* Add any trailing message bits and set the resulting string as the
* interpreter result. Caller is responsible for reporting this as an
* actual error.
*/
if (message != NULL) {
Tcl_AppendStringsToObj(objPtr, message, NULL);
}
Tcl_AppendStringsToObj(objPtr, "\"", NULL);
Tcl_SetObjResult(interp, objPtr);
#undef MAY_QUOTE_WORD
#undef AFTER_FIRST_WORD
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
|
