/*
* tclListObj.c --
*
* This file contains functions that implement the Tcl list object type.
*
* Copyright © 2022 Ashok P. Nadkarni. All rights reserved.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*/
#include <assert.h>
#include "tclInt.h"
#include "tclTomMath.h"
#include "tclArithSeries.h"
/*
* TODO - memmove is fast. Measure at what size we should prefer memmove
* (for unshared objects only) in lieu of range operations. On the other
* hand, more cache dirtied?
*/
/*
* Macros for validation and bug checking.
*/
/*
* Control whether asserts are enabled. Always enable in debug builds. In non-debug
* builds, can be set with cdebug="-DENABLE_LIST_ASSERTS" on the nmake command line.
*/
#ifdef ENABLE_LIST_ASSERTS
# ifdef NDEBUG
# undef NDEBUG /* Activate assert() macro */
# endif
#else
# ifndef NDEBUG
# define ENABLE_LIST_ASSERTS /* Always activate list asserts in debug mode */
# endif
#endif
#ifdef ENABLE_LIST_ASSERTS
#define LIST_ASSERT(cond_) assert(cond_) /* TODO - is there a Tcl-specific one? */
/*
* LIST_INDEX_ASSERT is to catch errors with negative indices and counts
* being passed AFTER validation. On Tcl9 length types are unsigned hence
* the checks against LIST_MAX. On Tcl8 length types are signed hence the
* also checks against 0.
*/
#define LIST_INDEX_ASSERT(idxarg_) \
do { \
Tcl_Size idx_ = (idxarg_); /* To guard against ++ etc. */ \
LIST_ASSERT(idx_ >= 0 && idx_ < LIST_MAX); \
} while (0)
/* Ditto for counts except upper limit is different */
#define LIST_COUNT_ASSERT(countarg_) \
do { \
Tcl_Size count_ = (countarg_); /* To guard against ++ etc. */ \
LIST_ASSERT(count_ >= 0 && count_ <= LIST_MAX); \
} while (0)
#else
#define LIST_ASSERT(cond_) ((void) 0)
#define LIST_INDEX_ASSERT(idx_) ((void) 0)
#define LIST_COUNT_ASSERT(count_) ((void) 0)
#endif
/* Checks for when caller should have already converted to internal list type */
#define LIST_ASSERT_TYPE(listObj_) \
LIST_ASSERT((listObj_)->typePtr == &tclListType.objType);
/*
* If ENABLE_LIST_INVARIANTS is enabled (-DENABLE_LIST_INVARIANTS from the
* command line), the entire list internal representation is checked for
* inconsistencies. This has a non-trivial cost so has to be separately
* enabled and not part of assertions checking. However, the test suite does
* invoke ListRepValidate directly even without ENABLE_LIST_INVARIANTS.
*/
#ifdef ENABLE_LIST_INVARIANTS
#define LISTREP_CHECK(listRepPtr_) ListRepValidate(listRepPtr_, __FILE__, __LINE__)
#else
#define LISTREP_CHECK(listRepPtr_) (void) 0
#endif
/*
* Flags used for controlling behavior of allocation of list
* internal representations.
*
* If the LISTREP_PANIC_ON_FAIL bit is set, the function will panic if
* list is too large or memory cannot be allocated. Without the flag
* a NULL pointer is returned.
*
* The LISTREP_SPACE_FAVOR_NONE, LISTREP_SPACE_FAVOR_FRONT,
* LISTREP_SPACE_FAVOR_BACK, LISTREP_SPACE_ONLY_BACK flags are used to
* control additional space when allocating.
* - If none of these flags is present, the exact space requested is
* allocated, nothing more.
* - Otherwise, if only LISTREP_FAVOR_FRONT is present, extra space is
* allocated with more towards the front.
* - Conversely, if only LISTREP_FAVOR_BACK is present extra space is allocated
* with more to the back.
* - If both flags are present (LISTREP_SPACE_FAVOR_NONE), the extra space
* is equally apportioned.
* - Finally if LISTREP_SPACE_ONLY_BACK is present, ALL extra space is at
* the back.
*/
#define LISTREP_PANIC_ON_FAIL 0x00000001
#define LISTREP_SPACE_FAVOR_FRONT 0x00000002
#define LISTREP_SPACE_FAVOR_BACK 0x00000004
#define LISTREP_SPACE_ONLY_BACK 0x00000008
#define LISTREP_SPACE_FAVOR_NONE \
(LISTREP_SPACE_FAVOR_FRONT | LISTREP_SPACE_FAVOR_BACK)
#define LISTREP_SPACE_FLAGS \
(LISTREP_SPACE_FAVOR_FRONT | LISTREP_SPACE_FAVOR_BACK \
| LISTREP_SPACE_ONLY_BACK)
/*
* Prototypes for non-inline static functions defined later in this file:
*/
static int MemoryAllocationError(Tcl_Interp *, Tcl_Size size);
static int ListLimitExceededError(Tcl_Interp *);
static ListStore *ListStoreNew(Tcl_Size objc, Tcl_Obj *const objv[], int flags);
static int ListRepInit(Tcl_Size objc, Tcl_Obj *const objv[], int flags, ListRep *);
static int ListRepInitAttempt(Tcl_Interp *,
Tcl_Size objc,
Tcl_Obj *const objv[],
ListRep *);
static void ListRepClone(ListRep *fromRepPtr, ListRep *toRepPtr, int flags);
static void ListRepUnsharedFreeUnreferenced(const ListRep *repPtr);
static int TclListObjGetRep(Tcl_Interp *, Tcl_Obj *listPtr, ListRep *repPtr);
static void ListRepRange(ListRep *srcRepPtr,
Tcl_Size rangeStart,
Tcl_Size rangeEnd,
int preserveSrcRep,
ListRep *rangeRepPtr);
static ListStore *ListStoreReallocate(ListStore *storePtr, Tcl_Size numSlots);
static void ListRepValidate(const ListRep *repPtr, const char *file,
int lineNum);
static void DupListInternalRep(Tcl_Obj *srcPtr, Tcl_Obj *copyPtr);
static void FreeListInternalRep(Tcl_Obj *listPtr);
static int SetListFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr);
static void UpdateStringOfList(Tcl_Obj *listPtr);
static Tcl_Size ListLength(Tcl_Obj *listPtr);
/*
* The structure below defines the list Tcl object type by means of functions
* that can be invoked by generic object code.
*
* The internal representation of a list object is ListRep defined in tcl.h.
*/
const TclObjTypeWithAbstractList tclListType = {
{"list", /* name */
FreeListInternalRep, /* freeIntRepProc */
DupListInternalRep, /* dupIntRepProc */
UpdateStringOfList, /* updateStringProc */
SetListFromAny, /* setFromAnyProc */
TCL_OBJTYPE_V0_1(
ListLength
)}
};
/* Macros to manipulate the List internal rep */
#define ListRepIncrRefs(repPtr_) \
do { \
(repPtr_)->storePtr->refCount++; \
if ((repPtr_)->spanPtr) \
(repPtr_)->spanPtr->refCount++; \
} while (0)
/* Returns number of free unused slots at the back of the ListRep's ListStore */
#define ListRepNumFreeTail(repPtr_) \
((repPtr_)->storePtr->numAllocated \
- ((repPtr_)->storePtr->firstUsed + (repPtr_)->storePtr->numUsed))
/* Returns number of free unused slots at the front of the ListRep's ListStore */
#define ListRepNumFreeHead(repPtr_) ((repPtr_)->storePtr->firstUsed)
/* Returns a pointer to the slot corresponding to list index listIdx_ */
#define ListRepSlotPtr(repPtr_, listIdx_) \
(&(repPtr_)->storePtr->slots[ListRepStart(repPtr_) + (listIdx_)])
/*
* Macros to replace the internal representation in a Tcl_Obj. There are
* subtle differences in each so make sure to use the right one to avoid
* memory leaks, access to freed memory and the like.
*
* ListObjStompRep - assumes the Tcl_Obj internal representation can be
* overwritten AND that the passed ListRep already has reference counts that
* include the reference from the Tcl_Obj. Basically just copies the pointers
* and sets the internal Tcl_Obj type to list
*
* ListObjOverwriteRep - like ListObjOverwriteRep but additionally
* increments reference counts on the passed ListRep. Generally used when
* the string representation of the Tcl_Obj is not to be modified.
*
* ListObjReplaceRepAndInvalidate - Like ListObjOverwriteRep but additionally
* assumes the Tcl_Obj internal rep is valid (and possibly even same as
* passed ListRep) and frees it first. Additionally invalidates the string
* representation. Generally used when modifying a Tcl_Obj value.
*/
#define ListObjStompRep(objPtr_, repPtr_) \
do { \
(objPtr_)->internalRep.twoPtrValue.ptr1 = (repPtr_)->storePtr; \
(objPtr_)->internalRep.twoPtrValue.ptr2 = (repPtr_)->spanPtr; \
(objPtr_)->typePtr = &tclListType.objType; \
} while (0)
#define ListObjOverwriteRep(objPtr_, repPtr_) \
do { \
ListRepIncrRefs(repPtr_); \
ListObjStompRep(objPtr_, repPtr_); \
} while (0)
#define ListObjReplaceRepAndInvalidate(objPtr_, repPtr_) \
do { \
/* Note order important, don't use ListObjOverwriteRep! */ \
ListRepIncrRefs(repPtr_); \
TclFreeInternalRep(objPtr_); \
TclInvalidateStringRep(objPtr_); \
ListObjStompRep(objPtr_, repPtr_); \
} while (0)
/*
*------------------------------------------------------------------------
*
* ListSpanNew --
*
* Allocates and initializes memory for a new ListSpan. The reference
* count on the returned struct is 0.
*
* Results:
* Non-NULL pointer to the allocated ListSpan.
*
* Side effects:
* The function will panic on memory allocation failure.
*
*------------------------------------------------------------------------
*/
static inline ListSpan *
ListSpanNew(
Tcl_Size firstSlot, /* Starting slot index of the span */
Tcl_Size numSlots) /* Number of slots covered by the span */
{
ListSpan *spanPtr = (ListSpan *) Tcl_Alloc(sizeof(*spanPtr));
spanPtr->refCount = 0;
spanPtr->spanStart = firstSlot;
spanPtr->spanLength = numSlots;
return spanPtr;
}
/*
*------------------------------------------------------------------------
*
* ListSpanDecrRefs --
*
* Decrements the reference count on a span, freeing the memory if
* it drops to zero or less.
*
* Results:
* None.
*
* Side effects:
* The memory may be freed.
*
*------------------------------------------------------------------------
*/
static inline void
ListSpanDecrRefs(ListSpan *spanPtr)
{
if (spanPtr->refCount <= 1) {
Tcl_Free(spanPtr);
} else {
spanPtr->refCount -= 1;
}
}
/*
*------------------------------------------------------------------------
*
* ListSpanMerited --
*
* Creation of a new list may sometimes be done as a span on existing
* storage instead of allocating new. The tradeoff is that if the
* original list is released, the new span-based list may hold on to
* more memory than desired. This function implements heuristics for
* deciding which option is better.
*
* Results:
* Returns non-0 if a span-based list is likely to be more optimal
* and 0 if not.
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
static inline int
ListSpanMerited(
Tcl_Size length, /* Length of the proposed span */
Tcl_Size usedStorageLength, /* Number of slots currently in used */
Tcl_Size allocatedStorageLength) /* Length of the currently allocation */
{
/*
TODO
- heuristics thresholds need to be determined
- currently, information about the sharing (ref count) of existing
storage is not passed. Perhaps it should be. For example if the
existing storage has a "large" ref count, then it might make sense
to do even a small span.
*/
if (length < LIST_SPAN_THRESHOLD) {
return 0;/* No span for small lists */
}
if (length < (allocatedStorageLength / 2 - allocatedStorageLength / 8)) {
return 0; /* No span if less than 3/8 of allocation */
}
if (length < usedStorageLength / 2) {
return 0; /* No span if less than half current storage */
}
return 1;
}
/*
*------------------------------------------------------------------------
*
* ListStoreUpSize --
*
* For reasons of efficiency, extra space is allocated for a ListStore
* compared to what was requested. This function calculates how many
* slots should actually be allocated for a given request size.
*
* Results:
* Number of slots to allocate.
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
static inline Tcl_Size
ListStoreUpSize(Tcl_Size numSlotsRequested) {
/* TODO -how much extra? May be double only for smaller requests? */
return numSlotsRequested < (LIST_MAX / 2) ? 2 * numSlotsRequested
: LIST_MAX;
}
/*
*------------------------------------------------------------------------
*
* ListRepFreeUnreferenced --
*
* Inline wrapper for ListRepUnsharedFreeUnreferenced that does quick checks
* before calling it.
*
* IMPORTANT: this function must not be called on an internal
* representation of a Tcl_Obj that is itself shared.
*
* Results:
* None.
*
* Side effects:
* See comments for ListRepUnsharedFreeUnreferenced.
*
*------------------------------------------------------------------------
*/
static inline void
ListRepFreeUnreferenced(const ListRep *repPtr)
{
if (! ListRepIsShared(repPtr) && repPtr->spanPtr) {
/* T:listrep-1.5.1 */
ListRepUnsharedFreeUnreferenced(repPtr);
}
}
/*
*------------------------------------------------------------------------
*
* ObjArrayIncrRefs --
*
* Increments the reference counts for Tcl_Obj's in a subarray.
*
* Results:
* None.
*
* Side effects:
* As above.
*
*------------------------------------------------------------------------
*/
static inline void
ObjArrayIncrRefs(
Tcl_Obj * const *objv, /* Pointer to the array */
Tcl_Size startIdx, /* Starting index of subarray within objv */
Tcl_Size count) /* Number of elements in the subarray */
{
Tcl_Obj * const *end;
LIST_INDEX_ASSERT(startIdx);
LIST_COUNT_ASSERT(count);
objv += startIdx;
end = objv + count;
while (objv < end) {
Tcl_IncrRefCount(*objv);
++objv;
}
}
/*
*------------------------------------------------------------------------
*
* ObjArrayDecrRefs --
*
* Decrements the reference counts for Tcl_Obj's in a subarray.
*
* Results:
* None.
*
* Side effects:
* As above.
*
*------------------------------------------------------------------------
*/
static inline void
ObjArrayDecrRefs(
Tcl_Obj * const *objv, /* Pointer to the array */
Tcl_Size startIdx, /* Starting index of subarray within objv */
Tcl_Size count) /* Number of elements in the subarray */
{
Tcl_Obj * const *end;
LIST_INDEX_ASSERT(startIdx);
LIST_COUNT_ASSERT(count);
objv += startIdx;
end = objv + count;
while (objv < end) {
Tcl_DecrRefCount(*objv);
++objv;
}
}
/*
*------------------------------------------------------------------------
*
* ObjArrayCopy --
*
* Copies an array of Tcl_Obj* pointers.
*
* Results:
* None.
*
* Side effects:
* Reference counts on copied Tcl_Obj's are incremented.
*
*------------------------------------------------------------------------
*/
static inline void
ObjArrayCopy(
Tcl_Obj **to, /* Destination */
Tcl_Size count, /* Number of pointers to copy */
Tcl_Obj *const from[]) /* Source array of Tcl_Obj* */
{
Tcl_Obj **end;
LIST_COUNT_ASSERT(count);
end = to + count;
/* TODO - would memmove followed by separate IncrRef loop be faster? */
while (to < end) {
Tcl_IncrRefCount(*from);
*to++ = *from++;
}
}
/*
*------------------------------------------------------------------------
*
* MemoryAllocationError --
*
* Generates a memory allocation failure error.
*
* Results:
* Always TCL_ERROR.
*
* Side effects:
* Error message and code are stored in the interpreter if not NULL.
*
*------------------------------------------------------------------------
*/
static int
MemoryAllocationError(
Tcl_Interp *interp, /* Interpreter for error message. May be NULL */
Tcl_Size size) /* Size of attempted allocation that failed */
{
if (interp != NULL) {
Tcl_SetObjResult(
interp,
Tcl_ObjPrintf(
"list construction failed: unable to alloc %" TCL_LL_MODIFIER
"u bytes",
(Tcl_WideInt)size));
Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
}
return TCL_ERROR;
}
/*
*------------------------------------------------------------------------
*
* ListLimitExceeded --
*
* Generates an error for exceeding maximum list size.
*
* Results:
* Always TCL_ERROR.
*
* Side effects:
* Error message and code are stored in the interpreter if not NULL.
*
*------------------------------------------------------------------------
*/
static int
ListLimitExceededError(Tcl_Interp *interp)
{
if (interp != NULL) {
Tcl_SetObjResult(
interp,
Tcl_NewStringObj("max length of a Tcl list exceeded", -1));
Tcl_SetErrorCode(interp, "TCL", "MEMORY", NULL);
}
return TCL_ERROR;
}
/*
*------------------------------------------------------------------------
*
* ListRepUnsharedShiftDown --
*
* Shifts the "in-use" contents in the ListStore for a ListRep down
* by the given number of slots. The ListStore must be unshared and
* the free space at the front of the storage area must be big enough.
* It is the caller's responsibility to check.
*
* Results:
* None.
*
* Side effects:
* The contents of the ListRep's ListStore area are shifted down in the
* storage area. The ListRep's ListSpan is updated accordingly.
*
*------------------------------------------------------------------------
*/
static inline void
ListRepUnsharedShiftDown(ListRep *repPtr, Tcl_Size shiftCount)
{
ListStore *storePtr;
LISTREP_CHECK(repPtr);
LIST_ASSERT(!ListRepIsShared(repPtr));
storePtr = repPtr->storePtr;
LIST_COUNT_ASSERT(shiftCount);
LIST_ASSERT(storePtr->firstUsed >= shiftCount);
memmove(&storePtr->slots[storePtr->firstUsed - shiftCount],
&storePtr->slots[storePtr->firstUsed],
storePtr->numUsed * sizeof(Tcl_Obj *));
storePtr->firstUsed -= shiftCount;
if (repPtr->spanPtr) {
repPtr->spanPtr->spanStart -= shiftCount;
LIST_ASSERT(repPtr->spanPtr->spanLength == storePtr->numUsed);
} else {
/*
* If there was no span, firstUsed must have been 0 (Invariant)
* AND shiftCount must have been 0 (<= firstUsed on call)
* In other words, this would have been a no-op
*/
LIST_ASSERT(storePtr->firstUsed == 0);
LIST_ASSERT(shiftCount == 0);
}
LISTREP_CHECK(repPtr);
}
/*
*------------------------------------------------------------------------
*
* ListRepUnsharedShiftUp --
*
* Shifts the "in-use" contents in the ListStore for a ListRep up
* by the given number of slots. The ListStore must be unshared and
* the free space at the back of the storage area must be big enough.
* It is the caller's responsibility to check.
* TODO - this function is not currently used.
*
* Results:
* None.
*
* Side effects:
* The contents of the ListRep's ListStore area are shifted up in the
* storage area. The ListRep's ListSpan is updated accordingly.
*
*------------------------------------------------------------------------
*/
#if 0
static inline void
ListRepUnsharedShiftUp(ListRep *repPtr, Tcl_Size shiftCount)
{
ListStore *storePtr;
LISTREP_CHECK(repPtr);
LIST_ASSERT(!ListRepIsShared(repPtr));
LIST_COUNT_ASSERT(shiftCount);
storePtr = repPtr->storePtr;
LIST_ASSERT((storePtr->firstUsed + storePtr->numUsed + shiftCount)
<= storePtr->numAllocated);
memmove(&storePtr->slots[storePtr->firstUsed + shiftCount],
&storePtr->slots[storePtr->firstUsed],
storePtr->numUsed * sizeof(Tcl_Obj *));
storePtr->firstUsed += shiftCount;
if (repPtr->spanPtr) {
repPtr->spanPtr->spanStart += shiftCount;
} else {
/* No span means entire original list is span */
/* Should have been zero before shift - Invariant TBD */
LIST_ASSERT(storePtr->firstUsed == shiftCount);
repPtr->spanPtr = ListSpanNew(shiftCount, storePtr->numUsed);
}
LISTREP_CHECK(repPtr);
}
#endif
/*
*------------------------------------------------------------------------
*
* ListRepValidate --
*
* Checks all invariants for a ListRep and panics on failure.
* Note this is independent of NDEBUG, assert etc.
*
* Results:
* None.
*
* Side effects:
* Panics if any invariant is not met.
*
*------------------------------------------------------------------------
*/
static void
ListRepValidate(const ListRep *repPtr, const char *file, int lineNum)
{
ListStore *storePtr = repPtr->storePtr;
const char *condition;
(void)storePtr; /* To stop gcc from whining about unused vars */
#define INVARIANT(cond_) \
do { \
if (!(cond_)) { \
condition = #cond_; \
goto failure; \
} \
} while (0)
/* Separate each condition so line number gives exact reason for failure */
INVARIANT(storePtr != NULL);
INVARIANT(storePtr->numAllocated <= LIST_MAX);
INVARIANT(storePtr->firstUsed < storePtr->numAllocated);
INVARIANT(storePtr->numUsed <= storePtr->numAllocated);
INVARIANT(storePtr->firstUsed <= (storePtr->numAllocated - storePtr->numUsed));
if (! ListRepIsShared(repPtr)) {
/*
* If this is the only reference and there is no span, then store
* occupancy must begin at 0
*/
INVARIANT(repPtr->spanPtr || repPtr->storePtr->firstUsed == 0);
}
INVARIANT(ListRepStart(repPtr) >= storePtr->firstUsed);
INVARIANT(ListRepLength(repPtr) <= storePtr->numUsed);
INVARIANT(ListRepStart(repPtr) <= (storePtr->firstUsed + storePtr->numUsed - ListRepLength(repPtr)));
#undef INVARIANT
return;
failure:
Tcl_Panic("List internal failure in %s line %d. Condition: %s",
file,
lineNum,
condition);
}
/*
*------------------------------------------------------------------------
*
* TclListObjValidate --
*
* Wrapper around ListRepValidate. Primarily used from test suite.
*
* Results:
* None.
*
* Side effects:
* Will panic if internal structure is not consistent or if object
* cannot be converted to a list object.
*
*------------------------------------------------------------------------
*/
void
TclListObjValidate(Tcl_Interp *interp, Tcl_Obj *listObj)
{
ListRep listRep;
if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK) {
Tcl_Panic("Object passed to TclListObjValidate cannot be converted to "
"a list object.");
}
ListRepValidate(&listRep, __FILE__, __LINE__);
}
/*
*----------------------------------------------------------------------
*
* ListStoreNew --
*
* Allocates a new ListStore with space for at least objc elements. objc
* must be > 0. If objv!=NULL, initializes with the first objc values
* in that array. If objv==NULL, initalize 0 elements, with space
* to add objc more.
*
* Normally the function allocates the exact space requested unless
* the flags arguments has any LISTREP_SPACE_*
* bits set. See the comments for those #defines.
*
* Results:
* On success, a pointer to the allocated ListStore is returned.
* On allocation failure, panics if LISTREP_PANIC_ON_FAIL is set in
* flags; otherwise returns NULL.
*
* Side effects:
* The ref counts of the elements in objv are incremented on success
* since the returned ListStore references them.
*
*----------------------------------------------------------------------
*/
static ListStore *
ListStoreNew(
Tcl_Size objc,
Tcl_Obj *const objv[],
int flags)
{
ListStore *storePtr;
Tcl_Size capacity;
/*
* First check to see if we'd overflow and try to allocate an object
* larger than our memory allocator allows.
*/
if (objc > LIST_MAX) {
if (flags & LISTREP_PANIC_ON_FAIL) {
Tcl_Panic("max length of a Tcl list exceeded");
}
return NULL;
}
if (flags & LISTREP_SPACE_FLAGS) {
capacity = ListStoreUpSize(objc);
} else {
capacity = objc;
}
storePtr = (ListStore *)Tcl_AttemptAlloc(LIST_SIZE(capacity));
if (storePtr == NULL && capacity != objc) {
capacity = objc; /* Try allocating exact size */
storePtr = (ListStore *)Tcl_AttemptAlloc(LIST_SIZE(capacity));
}
if (storePtr == NULL) {
if (flags & LISTREP_PANIC_ON_FAIL) {
Tcl_Panic("list creation failed: unable to alloc %" TCL_Z_MODIFIER "u bytes",
LIST_SIZE(objc));
}
return NULL;
}
storePtr->refCount = 0;
storePtr->flags = 0;
storePtr->numAllocated = capacity;
if (capacity == objc) {
storePtr->firstUsed = 0;
} else {
Tcl_Size extra = capacity - objc;
int spaceFlags = flags & LISTREP_SPACE_FLAGS;
if (spaceFlags == LISTREP_SPACE_ONLY_BACK) {
storePtr->firstUsed = 0;
} else if (spaceFlags == LISTREP_SPACE_FAVOR_FRONT) {
/* Leave more space in the front */
storePtr->firstUsed =
extra - (extra / 4); /* NOT same as 3*extra/4 */
} else if (spaceFlags == LISTREP_SPACE_FAVOR_BACK) {
/* Leave more space in the back */
storePtr->firstUsed = extra / 4;
} else {
/* Apportion equally */
storePtr->firstUsed = extra / 2;
}
}
if (objv) {
storePtr->numUsed = objc;
ObjArrayCopy(&storePtr->slots[storePtr->firstUsed], objc, objv);
} else {
storePtr->numUsed = 0;
}
return storePtr;
}
/*
*------------------------------------------------------------------------
*
* ListStoreReallocate --
*
* Reallocates the memory for a ListStore.
*
* Results:
* Pointer to the ListStore which may be the same as storePtr or pointer
* to a new block of memory. On reallocation failure, NULL is returned.
*
*
* Side effects:
* The memory pointed to by storePtr is freed if it a new block has to
* be returned.
*
*
*------------------------------------------------------------------------
*/
ListStore *
ListStoreReallocate (ListStore *storePtr, Tcl_Size numSlots)
{
Tcl_Size newCapacity;
ListStore *newStorePtr;
newCapacity = ListStoreUpSize(numSlots);
newStorePtr =
(ListStore *)Tcl_AttemptRealloc(storePtr, LIST_SIZE(newCapacity));
if (newStorePtr == NULL) {
newCapacity = numSlots;
newStorePtr = (ListStore *)Tcl_AttemptRealloc(storePtr,
LIST_SIZE(newCapacity));
if (newStorePtr == NULL)
return NULL;
}
/* Only the capacity has changed, fix it in the header */
newStorePtr->numAllocated = newCapacity;
return newStorePtr;
}
/*
*----------------------------------------------------------------------
*
* ListRepInit --
*
* Initializes a ListRep to hold a list internal representation
* with space for objc elements.
*
* objc must be > 0. If objv!=NULL, initializes with the first objc
* values in that array. If objv==NULL, initalize list internal rep to
* have 0 elements, with space to add objc more.
*
* Normally the function allocates the exact space requested unless
* the flags arguments has one of the LISTREP_SPACE_* bits set.
* See the comments for those #defines.
*
* The reference counts of the ListStore and ListSpan (if present)
* pointed to by the initialized repPtr are set to zero.
* Caller has to manage them as necessary.
*
* Results:
* On success, TCL_OK is returned with *listRepPtr initialized.
* On failure, panics if LISTREP_PANIC_ON_FAIL is set in flags; otherwise
* returns TCL_ERROR with *listRepPtr fields set to NULL.
*
* Side effects:
* The ref counts of the elements in objv are incremented since the
* resulting list now refers to them.
*
*----------------------------------------------------------------------
*/
static int
ListRepInit(
Tcl_Size objc,
Tcl_Obj *const objv[],
int flags,
ListRep *repPtr
)
{
ListStore *storePtr;
storePtr = ListStoreNew(objc, objv, flags);
if (storePtr) {
repPtr->storePtr = storePtr;
if (storePtr->firstUsed == 0) {
repPtr->spanPtr = NULL;
} else {
repPtr->spanPtr =
ListSpanNew(storePtr->firstUsed, storePtr->numUsed);
}
return TCL_OK;
}
/*
* Initialize to keep gcc happy at the call site. Else it complains
* about possibly uninitialized use.
*/
repPtr->storePtr = NULL;
repPtr->spanPtr = NULL;
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* ListRepInitAttempt --
*
* Creates a list internal rep with space for objc elements. See
* ListRepInit for requirements for parameters (in particular objc must
* be > 0). This function only adds error messages to the interpreter if
* not NULL.
*
* The reference counts of the ListStore and ListSpan (if present)
* pointed to by the initialized repPtr are set to zero.
* Caller has to manage them as necessary.
*
* Results:
* On success, TCL_OK is returned with *listRepPtr initialized.
* On allocation failure, returnes TCL_ERROR with an error message
* in the interpreter if non-NULL.
*
* Side effects:
* The ref counts of the elements in objv are incremented since the
* resulting list now refers to them.
*
*----------------------------------------------------------------------
*/
static int
ListRepInitAttempt(
Tcl_Interp *interp,
Tcl_Size objc,
Tcl_Obj *const objv[],
ListRep *repPtr)
{
int result = ListRepInit(objc, objv, 0, repPtr);
if (result != TCL_OK && interp != NULL) {
if (objc > LIST_MAX) {
ListLimitExceededError(interp);
} else {
MemoryAllocationError(interp, LIST_SIZE(objc));
}
}
return result;
}
/*
*------------------------------------------------------------------------
*
* ListRepClone --
*
* Does a deep clone of an existing ListRep.
*
* Normally the function allocates the exact space needed unless
* the flags arguments has one of the LISTREP_SPACE_* bits set.
* See the comments for those #defines.
*
* Results:
* None.
*
* Side effects:
* The toRepPtr location is initialized with the ListStore and ListSpan
* (if needed) containing a copy of the list elements in fromRepPtr.
* The function will panic if memory cannot be allocated.
*
*------------------------------------------------------------------------
*/
static void
ListRepClone(ListRep *fromRepPtr, ListRep *toRepPtr, int flags)
{
Tcl_Obj **fromObjs;
Tcl_Size numFrom;
ListRepElements(fromRepPtr, numFrom, fromObjs);
ListRepInit(numFrom, fromObjs, flags | LISTREP_PANIC_ON_FAIL, toRepPtr);
}
/*
*------------------------------------------------------------------------
*
* ListRepUnsharedFreeUnreferenced --
*
* Frees any Tcl_Obj's from the "in-use" area of the ListStore for a
* ListRep that are not actually references from any lists.
*
* IMPORTANT: this function must not be called on a shared internal
* representation or the internal representation of a shared Tcl_Obj.
*
* Results:
* None.
*
* Side effects:
* The firstUsed and numUsed fields of the ListStore are updated to
* reflect the new "in-use" extent.
*
*------------------------------------------------------------------------
*/
static void ListRepUnsharedFreeUnreferenced(const ListRep *repPtr)
{
Tcl_Size count;
ListStore *storePtr;
ListSpan *spanPtr;
LIST_ASSERT(!ListRepIsShared(repPtr));
LISTREP_CHECK(repPtr);
storePtr = repPtr->storePtr;
spanPtr = repPtr->spanPtr;
if (spanPtr == NULL) {
LIST_ASSERT(storePtr->firstUsed == 0); /* Invariant TBD */
return;
}
/* Collect garbage at front */
count = spanPtr->spanStart - storePtr->firstUsed;
LIST_COUNT_ASSERT(count);
if (count > 0) {
/* T:listrep-1.5.1,6.{1:8} */
ObjArrayDecrRefs(storePtr->slots, storePtr->firstUsed, count);
storePtr->firstUsed = spanPtr->spanStart;
LIST_ASSERT(storePtr->numUsed >= count);
storePtr->numUsed -= count;
}
/* Collect garbage at back */
count = (storePtr->firstUsed + storePtr->numUsed)
- (spanPtr->spanStart + spanPtr->spanLength);
LIST_COUNT_ASSERT(count);
if (count > 0) {
/* T:listrep-6.{1:8} */
ObjArrayDecrRefs(
storePtr->slots, spanPtr->spanStart + spanPtr->spanLength, count);
LIST_ASSERT(storePtr->numUsed >= count);
storePtr->numUsed -= count;
}
LIST_ASSERT(ListRepStart(repPtr) == storePtr->firstUsed);
LIST_ASSERT(ListRepLength(repPtr) == storePtr->numUsed);
LISTREP_CHECK(repPtr);
}
/*
*----------------------------------------------------------------------
*
* Tcl_NewListObj --
*
* This function is normally called when not debugging: i.e., when
* TCL_MEM_DEBUG is not defined. It creates a new list object from an
* (objc,objv) array: that is, each of the objc elements of the array
* referenced by objv is inserted as an element into a new Tcl object.
*
* When TCL_MEM_DEBUG is defined, this function just returns the result
* of calling the debugging version Tcl_DbNewListObj.
*
* Results:
* A new list object is returned that is initialized from the object
* pointers in objv. If objc is less than or equal to zero, an empty
* object is returned. The new object's string representation is left
* NULL. The resulting new list object has ref count 0.
*
* Side effects:
* The ref counts of the elements in objv are incremented since the
* resulting list now refers to them.
*
*----------------------------------------------------------------------
*/
#ifdef TCL_MEM_DEBUG
#undef Tcl_NewListObj
Tcl_Obj *
Tcl_NewListObj(
Tcl_Size objc, /* Count of objects referenced by objv. */
Tcl_Obj *const objv[]) /* An array of pointers to Tcl objects. */
{
return Tcl_DbNewListObj(objc, objv, "unknown", 0);
}
#else /* if not TCL_MEM_DEBUG */
Tcl_Obj *
Tcl_NewListObj(
Tcl_Size objc, /* Count of objects referenced by objv. */
Tcl_Obj *const objv[]) /* An array of pointers to Tcl objects. */
{
ListRep listRep;
Tcl_Obj *listObj;
TclNewObj(listObj);
if (objc + 1 <= 1) {
return listObj;
}
ListRepInit(objc, objv, LISTREP_PANIC_ON_FAIL, &listRep);
ListObjReplaceRepAndInvalidate(listObj, &listRep);
return listObj;
}
#endif /* if TCL_MEM_DEBUG */
/*
*----------------------------------------------------------------------
*
* Tcl_DbNewListObj --
*
* This function is normally called when debugging: i.e., when
* TCL_MEM_DEBUG is defined. It creates new list objects. It is the same
* as the Tcl_NewListObj function above except that it calls
* Tcl_DbCkalloc directly with the file name and line number from its
* caller. This simplifies debugging since then the [memory active]
* command will report the correct file name and line number when
* reporting objects that haven't been freed.
*
* When TCL_MEM_DEBUG is not defined, this function just returns the
* result of calling Tcl_NewListObj.
*
* Results:
* A new list object is returned that is initialized from the object
* pointers in objv. If objc is less than or equal to zero, an empty
* object is returned. The new object's string representation is left
* NULL. The new list object has ref count 0.
*
* Side effects:
* The ref counts of the elements in objv are incremented since the
* resulting list now refers to them.
*
*----------------------------------------------------------------------
*/
#ifdef TCL_MEM_DEBUG
Tcl_Obj *
Tcl_DbNewListObj(
Tcl_Size objc, /* Count of objects referenced by objv. */
Tcl_Obj *const objv[], /* An array of pointers to Tcl objects. */
const char *file, /* The name of the source file calling this
* function; used for debugging. */
int line) /* Line number in the source file; used for
* debugging. */
{
Tcl_Obj *listObj;
ListRep listRep;
TclDbNewObj(listObj, file, line);
if (objc + 1 <= 1) {
return listObj;
}
ListRepInit(objc, objv, LISTREP_PANIC_ON_FAIL, &listRep);
ListObjReplaceRepAndInvalidate(listObj, &listRep);
return listObj;
}
#else /* if not TCL_MEM_DEBUG */
Tcl_Obj *
Tcl_DbNewListObj(
Tcl_Size objc, /* Count of objects referenced by objv. */
Tcl_Obj *const objv[], /* An array of pointers to Tcl objects. */
TCL_UNUSED(const char *) /*file*/,
TCL_UNUSED(int) /*line*/)
{
return Tcl_NewListObj(objc, objv);
}
#endif /* TCL_MEM_DEBUG */
/*
*------------------------------------------------------------------------
*
* TclNewListObj2 --
*
* Create a new Tcl_Obj list comprising of the concatenation of two
* Tcl_Obj* arrays.
* TODO - currently this function is not used within tclListObj but
* need to see if it would be useful in other files that preallocate
* lists and then append.
*
* Results:
* Non-NULL pointer to the allocate Tcl_Obj.
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
Tcl_Obj *
TclNewListObj2(
Tcl_Size objc1, /* Count of objects referenced by objv1. */
Tcl_Obj *const objv1[], /* First array of pointers to Tcl objects. */
Tcl_Size objc2, /* Count of objects referenced by objv2. */
Tcl_Obj *const objv2[] /* Second array of pointers to Tcl objects. */
)
{
Tcl_Obj *listObj;
ListStore *storePtr;
Tcl_Size objc = objc1 + objc2;
listObj = Tcl_NewListObj(objc, NULL);
if (objc == 0) {
return listObj; /* An empty object */
}
LIST_ASSERT_TYPE(listObj);
storePtr = ListObjStorePtr(listObj);
LIST_ASSERT(ListObjSpanPtr(listObj) == NULL);
LIST_ASSERT(storePtr->firstUsed == 0);
LIST_ASSERT(storePtr->numUsed == 0);
LIST_ASSERT(storePtr->numAllocated >= objc);
if (objc1) {
ObjArrayCopy(storePtr->slots, objc1, objv1);
}
if (objc2) {
ObjArrayCopy(&storePtr->slots[objc1], objc2, objv2);
}
storePtr->numUsed = objc;
return listObj;
}
/*
*----------------------------------------------------------------------
*
* TclListObjGetRep --
*
* This function returns a copy of the ListRep stored
* as the internal representation of an object. The reference
* counts of the (ListStore, ListSpan) contained in the representation
* are NOT incremented.
*
* Results:
* The return value is normally TCL_OK; in this case *listRepP
* is set to a copy of the descriptor stored as the internal
* representation of the Tcl_Obj containing a list. if listPtr does not
* refer to a list object and the object can not be converted to one,
* TCL_ERROR is returned and an error message will be left in the
* interpreter's result if interp is not NULL.
*
* Side effects:
* The possible conversion of the object referenced by listPtr
* to a list object. *repPtr is initialized to the internal rep
* if result is TCL_OK, or set to NULL on error.
*----------------------------------------------------------------------
*/
static int
TclListObjGetRep(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *listObj, /* List object for which an element array is
* to be returned. */
ListRep *repPtr) /* Location to store descriptor */
{
if (!TclHasInternalRep(listObj, &tclListType.objType)) {
int result;
result = SetListFromAny(interp, listObj);
if (result != TCL_OK) {
/* Init to keep gcc happy wrt uninitialized fields at call site */
repPtr->storePtr = NULL;
repPtr->spanPtr = NULL;
return result;
}
}
ListObjGetRep(listObj, repPtr);
LISTREP_CHECK(repPtr);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetListObj --
*
* Modify an object to be a list containing each of the objc elements of
* the object array referenced by objv.
*
* Results:
* None.
*
* Side effects:
* The object is made a list object and is initialized from the object
* pointers in objv. If objc is less than or equal to zero, an empty
* object is returned. The new object's string representation is left
* NULL. The ref counts of the elements in objv are incremented since the
* list now refers to them. The object's old string and internal
* representations are freed and its type is set NULL.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetListObj(
Tcl_Obj *objPtr, /* Object whose internal rep to init. */
Tcl_Size objc, /* Count of objects referenced by objv. */
Tcl_Obj *const objv[]) /* An array of pointers to Tcl objects. */
{
if (Tcl_IsShared(objPtr)) {
Tcl_Panic("%s called with shared object", "Tcl_SetListObj");
}
/*
* Set the object's type to "list" and initialize the internal rep.
* However, if there are no elements to put in the list, just give the
* object an empty string rep and a NULL type. NOTE ListRepInit must
* not be called with objc == 0!
*/
if (objc + 1 > 1) {
ListRep listRep;
/* TODO - perhaps ask for extra space? */
ListRepInit(objc, objv, LISTREP_PANIC_ON_FAIL, &listRep);
ListObjReplaceRepAndInvalidate(objPtr, &listRep);
} else {
TclFreeInternalRep(objPtr);
TclInvalidateStringRep(objPtr);
Tcl_InitStringRep(objPtr, NULL, 0);
}
}
/*
*----------------------------------------------------------------------
*
* TclListObjCopy --
*
* Makes a "pure list" copy of a list value. This provides for the C
* level a counterpart of the [lrange $list 0 end] command, while using
* internals details to be as efficient as possible.
*
* Results:
* Normally returns a pointer to a new Tcl_Obj, that contains the same
* list value as *listPtr does. The returned Tcl_Obj has a refCount of
* zero. If *listPtr does not hold a list, NULL is returned, and if
* interp is non-NULL, an error message is recorded there.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_Obj *
TclListObjCopy(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *listObj) /* List object for which an element array is
* to be returned. */
{
Tcl_Obj *copyObj;
if (!TclHasInternalRep(listObj, &tclListType.objType)) {
if (TclHasInternalRep(listObj,&tclArithSeriesType.objType)) {
return TclArithSeriesObjCopy(interp, listObj);
}
if (SetListFromAny(interp, listObj) != TCL_OK) {
return NULL;
}
}
TclNewObj(copyObj);
TclInvalidateStringRep(copyObj);
DupListInternalRep(listObj, copyObj);
return copyObj;
}
/*
*------------------------------------------------------------------------
*
* ListRepRange --
*
* Initializes a ListRep as a range within the passed ListRep.
* The range limits are clamped to the list boundaries.
*
* Results:
* None.
*
* Side effects:
* The ListStore and ListSpan referenced by in the returned ListRep
* may or may not be the same as those passed in. For example, the
* ListStore may differ because the range is small enough that a new
* ListStore is more memory-optimal. The ListSpan may differ because
* it is NULL or shared. Regardless, reference counts on the returned
* values are not incremented. Generally, ListObjReplaceRepAndInvalidate
* may be used to store the new ListRep back into an object or a
* ListRepIncrRefs followed by ListRepDecrRefs to free in case of errors.
* Any other use should be carefully reconsidered.
* TODO WARNING:- this is an awkward interface and easy for caller
* to get wrong. Mostly due to refcount combinations. Perhaps passing
* in the source listObj instead of source listRep might simplify.
*
*------------------------------------------------------------------------
*/
static void
ListRepRange(
ListRep *srcRepPtr, /* Contains source of the range */
Tcl_Size rangeStart, /* Index of first element to include */
Tcl_Size rangeEnd, /* Index of last element to include */
int preserveSrcRep, /* If true, srcRepPtr contents must not be
modified (generally because a shared Tcl_Obj
references it) */
ListRep *rangeRepPtr) /* Output. Must NOT be == srcRepPtr */
{
Tcl_Obj **srcElems;
Tcl_Size numSrcElems = ListRepLength(srcRepPtr);
Tcl_Size rangeLen;
Tcl_Size numAfterRangeEnd;
LISTREP_CHECK(srcRepPtr);
/* Take the opportunity to garbage collect */
/* TODO - we probably do not need the preserveSrcRep here unlike later */
if (!preserveSrcRep) {
/* T:listrep-1.{4,5,8,9},2.{4:7},3.{15:18},4.{7,8} */
ListRepFreeUnreferenced(srcRepPtr);
} /* else T:listrep-2.{4.2,4.3,5.2,5.3,6.2,7.2,8.1} */
if (rangeStart < 0) {
rangeStart = 0;
}
if (rangeEnd >= numSrcElems) {
rangeEnd = numSrcElems - 1;
}
if (rangeStart > rangeEnd) {
/* Empty list of capacity 1. */
ListRepInit(1, NULL, LISTREP_PANIC_ON_FAIL, rangeRepPtr);
return;
}
rangeLen = rangeEnd - rangeStart + 1;
/*
* We can create a range one of four ways:
* (0) Range encapsulates entire list
* (1) Special case: deleting in-place from end of an unshared object
* (2) Use a ListSpan referencing the current ListStore
* (3) Creating a new ListStore
* (4) Removing all elements outside the range in the current ListStore
* Option (4) may only be done if caller has not disallowed it AND
* the ListStore is not shared.
*
* The choice depends on heuristics related to speed and memory.
* TODO - heuristics below need to be measured and tuned.
*
* Note: Even if nothing below cause any changes, we still want the
* string-canonizing effect of [lrange 0 end] so the Tcl_Obj should not
* be returned as is even if the range encompasses the whole list.
*/
if (rangeStart == 0 && rangeEnd == (numSrcElems-1)) {
/* Option 0 - entire list. This may be used to canonicalize */
/* T:listrep-1.10.1,2.8.1 */
*rangeRepPtr = *srcRepPtr; /* Not ref counts not incremented */
} else if (rangeStart == 0 && (!preserveSrcRep)
&& (!ListRepIsShared(srcRepPtr) && srcRepPtr->spanPtr == NULL)) {
/* Option 1 - Special case unshared, exclude end elements, no span */
LIST_ASSERT(srcRepPtr->storePtr->firstUsed == 0); /* If no span */
ListRepElements(srcRepPtr, numSrcElems, srcElems);
numAfterRangeEnd = numSrcElems - (rangeEnd + 1);
/* Assert: Because numSrcElems > rangeEnd earlier */
if (numAfterRangeEnd != 0) {
/* T:listrep-1.{8,9} */
ObjArrayDecrRefs(srcElems, rangeEnd + 1, numAfterRangeEnd);
}
/* srcRepPtr->storePtr->firstUsed,numAllocated unchanged */
srcRepPtr->storePtr->numUsed = rangeLen;
srcRepPtr->storePtr->flags = 0;
rangeRepPtr->storePtr = srcRepPtr->storePtr; /* Note no incr ref */
rangeRepPtr->spanPtr = NULL;
} else if (ListSpanMerited(rangeLen,
srcRepPtr->storePtr->numUsed,
srcRepPtr->storePtr->numAllocated)) {
/* Option 2 - because span would be most efficient */
Tcl_Size spanStart = ListRepStart(srcRepPtr) + rangeStart;
if (!preserveSrcRep && srcRepPtr->spanPtr
&& srcRepPtr->spanPtr->refCount <= 1) {
/* If span is not shared reuse it */
/* T:listrep-2.7.3,3.{16,18} */
srcRepPtr->spanPtr->spanStart = spanStart;
srcRepPtr->spanPtr->spanLength = rangeLen;
*rangeRepPtr = *srcRepPtr;
} else {
/* Span not present or is shared. */
/* T:listrep-1.5,2.{5,7},4.{7,8} */
rangeRepPtr->storePtr = srcRepPtr->storePtr;
rangeRepPtr->spanPtr = ListSpanNew(spanStart, rangeLen);
}
/*
* We have potentially created a new internal representation that
* references the same storage as srcRep but not yet incremented its
* reference count. So do NOT call freezombies if preserveSrcRep
* is mandated.
*/
if (!preserveSrcRep) {
/* T:listrep-1.{5.1,5.2,5.4},2.{5,7},3.{16,18},4.{7,8} */
ListRepFreeUnreferenced(rangeRepPtr);
}
} else if (preserveSrcRep || ListRepIsShared(srcRepPtr)) {
/* Option 3 - span or modification in place not allowed/desired */
/* T:listrep-2.{4,6} */
ListRepElements(srcRepPtr, numSrcElems, srcElems);
/* TODO - allocate extra space? */
ListRepInit(rangeLen,
&srcElems[rangeStart],
LISTREP_PANIC_ON_FAIL,
rangeRepPtr);
} else {
/*
* Option 4 - modify in place. Note that because of the invariant
* that spanless list stores must start at 0, we have to move
* everything to the front.
* TODO - perhaps if a span already exists, no need to move to front?
* or maybe no need to move all the way to the front?
* TODO - if range is small relative to allocation, allocate new?
*/
/* Asserts follow from call to ListRepFreeUnreferenced earlier */
LIST_ASSERT(!preserveSrcRep);
LIST_ASSERT(!ListRepIsShared(srcRepPtr));
LIST_ASSERT(ListRepStart(srcRepPtr) == srcRepPtr->storePtr->firstUsed);
LIST_ASSERT(ListRepLength(srcRepPtr) == srcRepPtr->storePtr->numUsed);
ListRepElements(srcRepPtr, numSrcElems, srcElems);
/* Free leading elements outside range */
if (rangeStart != 0) {
/* T:listrep-1.4,3.15 */
ObjArrayDecrRefs(srcElems, 0, rangeStart);
}
/* Ditto for trailing */
numAfterRangeEnd = numSrcElems - (rangeEnd + 1);
/* Assert: Because numSrcElems > rangeEnd earlier */
if (numAfterRangeEnd != 0) {
/* T:listrep-3.17 */
ObjArrayDecrRefs(srcElems, rangeEnd + 1, numAfterRangeEnd);
}
memmove(&srcRepPtr->storePtr->slots[0],
&srcRepPtr->storePtr
->slots[srcRepPtr->storePtr->firstUsed + rangeStart],
rangeLen * sizeof(Tcl_Obj *));
srcRepPtr->storePtr->firstUsed = 0;
srcRepPtr->storePtr->numUsed = rangeLen;
srcRepPtr->storePtr->flags = 0;
if (srcRepPtr->spanPtr) {
/* In case the source has a span, update it for consistency */
/* T:listrep-3.{15,17} */
srcRepPtr->spanPtr->spanStart = srcRepPtr->storePtr->firstUsed;
srcRepPtr->spanPtr->spanLength = srcRepPtr->storePtr->numUsed;
}
rangeRepPtr->storePtr = srcRepPtr->storePtr;
rangeRepPtr->spanPtr = NULL;
}
/* TODO - call freezombies here if !preserveSrcRep? */
/* Note ref counts intentionally not incremented */
LISTREP_CHECK(rangeRepPtr);
return;
}
/*
*----------------------------------------------------------------------
*
* TclListObjRange --
*
* Makes a slice of a list value.
* *listObj must be known to be a valid list.
*
* Results:
* Returns a pointer to the sliced list.
* This may be a new object or the same object if not shared.
* Returns NULL if passed listObj was not a list and could not be
* converted to one.
*
* Side effects:
* The possible conversion of the object referenced by listPtr
* to a list object.
*
*----------------------------------------------------------------------
*/
Tcl_Obj *
TclListObjRange(
Tcl_Obj *listObj, /* List object to take a range from. */
Tcl_Size rangeStart, /* Index of first element to include. */
Tcl_Size rangeEnd) /* Index of last element to include. */
{
ListRep listRep;
ListRep resultRep;
int isShared;
if (TclListObjGetRep(NULL, listObj, &listRep) != TCL_OK)
return NULL;
isShared = Tcl_IsShared(listObj);
ListRepRange(&listRep, rangeStart, rangeEnd, isShared, &resultRep);
if (isShared) {
/* T:listrep-1.10.1,2.{4.2,4.3,5.2,5.3,6.2,7.2,8.1} */
TclNewObj(listObj);
} /* T:listrep-1.{4.3,5.1,5.2} */
ListObjReplaceRepAndInvalidate(listObj, &resultRep);
return listObj;
}
/*
*----------------------------------------------------------------------
*
* Tcl_ListObjGetElements --
*
* This function returns an (objc,objv) array of the elements in a list
* object.
*
* Results:
* The return value is normally TCL_OK; in this case *objcPtr is set to
* the count of list elements and *objvPtr is set to a pointer to an
* array of (*objcPtr) pointers to each list element. If listPtr does not
* refer to a list object and the object can not be converted to one,
* TCL_ERROR is returned and an error message will be left in the
* interpreter's result if interp is not NULL.
*
* The objects referenced by the returned array should be treated as
* readonly and their ref counts are _not_ incremented; the caller must
* do that if it holds on to a reference. Furthermore, the pointer and
* length returned by this function may change as soon as any function is
* called on the list object; be careful about retaining the pointer in a
* local data structure.
*
* Side effects:
* The possible conversion of the object referenced by listPtr
* to a list object.
*
*----------------------------------------------------------------------
*/
#undef Tcl_ListObjGetElements
int
Tcl_ListObjGetElements(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *objPtr, /* List object for which an element array is
* to be returned. */
Tcl_Size *objcPtr, /* Where to store the count of objects
* referenced by objv. */
Tcl_Obj ***objvPtr) /* Where to store the pointer to an array of
* pointers to the list's objects. */
{
ListRep listRep;
if (TclHasInternalRep(objPtr,&tclArithSeriesType.objType)) {
return TclArithSeriesGetElements(interp, objPtr, objcPtr, objvPtr);
}
if (TclListObjGetRep(interp, objPtr, &listRep) != TCL_OK)
return TCL_ERROR;
ListRepElements(&listRep, *objcPtr, *objvPtr);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_ListObjAppendList --
*
* This function appends the elements in the list fromObj
* to toObj. toObj must not be shared else the function will panic.
*
* Results:
* The return value is normally TCL_OK. If fromObj or toObj do not
* refer to list values, TCL_ERROR is returned and an error message is
* left in the interpreter's result if interp is not NULL.
*
* Side effects:
* The reference counts of the elements in fromObj are incremented
* since the list now refers to them. toObj and fromObj are
* converted, if necessary, to list objects. Also, appending the new
* elements may cause toObj's array of element pointers to grow.
* toObj's old string representation, if any, is invalidated.
*
*----------------------------------------------------------------------
*/
int
Tcl_ListObjAppendList(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *toObj, /* List object to append elements to. */
Tcl_Obj *fromObj) /* List obj with elements to append. */
{
Tcl_Size objc;
Tcl_Obj **objv;
if (Tcl_IsShared(toObj)) {
Tcl_Panic("%s called with shared object", "Tcl_ListObjAppendList");
}
if (TclListObjGetElementsM(interp, fromObj, &objc, &objv) != TCL_OK) {
return TCL_ERROR;
}
/*
* Insert the new elements starting after the lists's last element.
* Delete zero existing elements.
*/
return TclListObjAppendElements(interp, toObj, objc, objv);
}
/*
*------------------------------------------------------------------------
*
* TclListObjAppendElements --
*
* Appends multiple elements to a Tcl_Obj list object. If
* the passed Tcl_Obj is not a list object, it will be converted to one
* and an error raised if the conversion fails.
*
* The Tcl_Obj must not be shared though the internal representation
* may be.
*
* Results:
* On success, TCL_OK is returned with the specified elements appended.
* On failure, TCL_ERROR is returned with an error message in the
* interpreter if not NULL.
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
int TclListObjAppendElements (
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *toObj, /* List object to append */
Tcl_Size elemCount, /* Number of elements in elemObjs[] */
Tcl_Obj * const elemObjv[]) /* Objects to append to toObj's list. */
{
ListRep listRep;
Tcl_Obj **toObjv;
Tcl_Size toLen;
Tcl_Size finalLen;
if (Tcl_IsShared(toObj)) {
Tcl_Panic("%s called with shared object", "TclListObjAppendElements");
}
if (TclListObjGetRep(interp, toObj, &listRep) != TCL_OK)
return TCL_ERROR; /* Cannot be converted to a list */
if (elemCount <= 0)
return TCL_OK; /* Nothing to do. Note AFTER check for list above */
ListRepElements(&listRep, toLen, toObjv);
if (elemCount > LIST_MAX || toLen > (LIST_MAX - elemCount)) {
return ListLimitExceededError(interp);
}
finalLen = toLen + elemCount;
if (!ListRepIsShared(&listRep)) {
/*
* Reuse storage if possible. Even if too small, realloc-ing instead
* of creating a new ListStore will save us on manipulating Tcl_Obj
* reference counts on the elements which is a substantial cost
* if the list is not small.
*/
Tcl_Size numTailFree;
ListRepFreeUnreferenced(&listRep); /* Collect garbage before checking room */
LIST_ASSERT(ListRepStart(&listRep) == listRep.storePtr->firstUsed);
LIST_ASSERT(ListRepLength(&listRep) == listRep.storePtr->numUsed);
LIST_ASSERT(toLen == listRep.storePtr->numUsed);
if (finalLen > listRep.storePtr->numAllocated) {
/* T:listrep-1.{2,11},3.6 */
ListStore *newStorePtr;
newStorePtr = ListStoreReallocate(listRep.storePtr, finalLen);
if (newStorePtr == NULL) {
return MemoryAllocationError(interp, LIST_SIZE(finalLen));
}
LIST_ASSERT(newStorePtr->numAllocated >= finalLen);
listRep.storePtr = newStorePtr;
/*
* WARNING: at this point the Tcl_Obj internal rep potentially
* points to freed storage if the reallocation returned a
* different location. Overwrite it to bring it back in sync.
*/
ListObjStompRep(toObj, &listRep);
} /* else T:listrep-3.{4,5} */
LIST_ASSERT(listRep.storePtr->numAllocated >= finalLen);
/* Current store big enough */
numTailFree = ListRepNumFreeTail(&listRep);
LIST_ASSERT((numTailFree + listRep.storePtr->firstUsed)
>= elemCount); /* Total free */
if (numTailFree < elemCount) {
/* Not enough room at back. Move some to front */
/* T:listrep-3.5 */
Tcl_Size shiftCount = elemCount - numTailFree;
/* Divide remaining space between front and back */
shiftCount += (listRep.storePtr->numAllocated - finalLen) / 2;
LIST_ASSERT(shiftCount <= listRep.storePtr->firstUsed);
if (shiftCount) {
/* T:listrep-3.5 */
ListRepUnsharedShiftDown(&listRep, shiftCount);
}
} /* else T:listrep-3.{4,6} */
ObjArrayCopy(&listRep.storePtr->slots[ListRepStart(&listRep)
+ ListRepLength(&listRep)],
elemCount,
elemObjv);
listRep.storePtr->numUsed = finalLen;
if (listRep.spanPtr) {
/* T:listrep-3.{4,5,6} */
LIST_ASSERT(listRep.spanPtr->spanStart
== listRep.storePtr->firstUsed);
listRep.spanPtr->spanLength = finalLen;
} /* else T:listrep-3.6.3 */
LIST_ASSERT(ListRepStart(&listRep) == listRep.storePtr->firstUsed);
LIST_ASSERT(ListRepLength(&listRep) == finalLen);
LISTREP_CHECK(&listRep);
ListObjReplaceRepAndInvalidate(toObj, &listRep);
return TCL_OK;
}
/*
* Have to make a new list rep, either shared or no room in old one.
* If the old list did not have a span (all elements at front), do
* not leave space in the front either, assuming all appends and no
* prepends.
*/
if (ListRepInit(finalLen,
NULL,
listRep.spanPtr ? LISTREP_SPACE_FAVOR_BACK
: LISTREP_SPACE_ONLY_BACK,
&listRep)
!= TCL_OK) {
return TCL_ERROR;
}
LIST_ASSERT(listRep.storePtr->numAllocated >= finalLen);
if (toLen) {
/* T:listrep-2.{2,9},4.5 */
ObjArrayCopy(ListRepSlotPtr(&listRep, 0), toLen, toObjv);
}
ObjArrayCopy(ListRepSlotPtr(&listRep, toLen), elemCount, elemObjv);
listRep.storePtr->numUsed = finalLen;
if (listRep.spanPtr) {
/* T:listrep-4.5 */
LIST_ASSERT(listRep.spanPtr->spanStart == listRep.storePtr->firstUsed);
listRep.spanPtr->spanLength = finalLen;
}
LISTREP_CHECK(&listRep);
ListObjReplaceRepAndInvalidate(toObj, &listRep);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_ListObjAppendElement --
*
* Like 'Tcl_ListObjAppendList', but Appends a single value to a list.
*
* Value
*
* TCL_OK
*
* 'objPtr' is appended to the elements of 'listPtr'.
*
* TCL_ERROR
*
* listPtr does not refer to a list object and the object can not be
* converted to one. An error message will be left in the
* interpreter's result if interp is not NULL.
*
* Effect
*
* If 'listPtr' is not already of type 'tclListType', it is converted.
* The 'refCount' of 'objPtr' is incremented as it is added to 'listPtr'.
* Appending the new element may cause the array of element pointers
* in 'listObj' to grow. Any preexisting string representation of
* 'listPtr' is invalidated.
*
*----------------------------------------------------------------------
*/
int
Tcl_ListObjAppendElement(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *toObj, /* List object to append elemObj to. */
Tcl_Obj *elemObj) /* Object to append to toObj's list. */
{
/*
* TODO - compare perf with 8.6 to see if worth optimizing single
* element case
*/
return TclListObjAppendElements(interp, toObj, 1, &elemObj);
}
/*
*----------------------------------------------------------------------
*
* Tcl_ListObjIndex --
*
* Retrieve a pointer to the element of 'listPtr' at 'index'. The index
* of the first element is 0.
*
* Value
*
* TCL_OK
*
* A pointer to the element at 'index' is stored in 'objPtrPtr'. If
* 'index' is out of range, NULL is stored in 'objPtrPtr'. This
* object should be treated as readonly and its 'refCount' is _not_
* incremented. The caller must do that if it holds on to the
* reference.
*
* TCL_ERROR
*
* 'listPtr' is not a valid list. An error message is left in the
* interpreter's result if 'interp' is not NULL.
*
* Effect
*
* If 'listPtr' is not already of type 'tclListType', it is converted.
*
*----------------------------------------------------------------------
*/
int
Tcl_ListObjIndex(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *listObj, /* List object to index into. */
Tcl_Size index, /* Index of element to return. */
Tcl_Obj **objPtrPtr) /* The resulting Tcl_Obj* is stored here. */
{
Tcl_Obj **elemObjs;
Tcl_Size numElems;
/*
* TODO
* Unlike the original list code, this does not optimize for lindex'ing
* an empty string when the internal rep is not already a list. On the
* other hand, this code will be faster for the case where the object
* is currently a dict. Benchmark the two cases.
*/
if (TclListObjGetElementsM(interp, listObj, &numElems, &elemObjs)
!= TCL_OK) {
return TCL_ERROR;
}
if (index < 0 || index >= numElems) {
*objPtrPtr = NULL;
} else {
*objPtrPtr = elemObjs[index];
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_ListObjLength --
*
* This function returns the number of elements in a list object. If the
* object is not already a list object, an attempt will be made to
* convert it to one.
*
* Results:
* The return value is normally TCL_OK; in this case *lenPtr will be set
* to the integer count of list elements. If listPtr does not refer to a
* list object and the object can not be converted to one, TCL_ERROR is
* returned and an error message will be left in the interpreter's result
* if interp is not NULL.
*
* Side effects:
* The possible conversion of the argument object to a list object.
*
*----------------------------------------------------------------------
*/
#undef Tcl_ListObjLength
int
Tcl_ListObjLength(
Tcl_Interp *interp, /* Used to report errors if not NULL. */
Tcl_Obj *listObj, /* List object whose #elements to return. */
Tcl_Size *lenPtr) /* The resulting length is stored here. */
{
ListRep listRep;
Tcl_Size (*lengthProc)(Tcl_Obj *obj) = ABSTRACTLIST_PROC(listObj, lengthProc);
if (lengthProc) {
*lenPtr = lengthProc(listObj);
return TCL_OK;
}
/*
* TODO
* Unlike the original list code, this does not optimize for lindex'ing
* an empty string when the internal rep is not already a list. On the
* other hand, this code will be faster for the case where the object
* is currently a dict. Benchmark the two cases.
*/
if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK) {
return TCL_ERROR;
}
*lenPtr = ListRepLength(&listRep);
return TCL_OK;
}
Tcl_Size
ListLength(Tcl_Obj *listPtr)
{
ListRep listRep;
ListObjGetRep(listPtr, &listRep);
return ListRepLength(&listRep);
}
/*
*----------------------------------------------------------------------
*
* Tcl_ListObjReplace --
*
* This function replaces zero or more elements of the list referenced by
* listObj with the objects from an (objc,objv) array. The objc elements
* of the array referenced by objv replace the count elements in listPtr
* starting at first.
*
* If the argument first is zero or negative, it refers to the first
* element. If first is greater than or equal to the number of elements
* in the list, then no elements are deleted; the new elements are
* appended to the list. Count gives the number of elements to replace.
* If count is zero or negative then no elements are deleted; the new
* elements are simply inserted before first.
*
* The argument objv refers to an array of objc pointers to the new
* elements to be added to listPtr in place of those that were deleted.
* If objv is NULL, no new elements are added. If listPtr is not a list
* object, an attempt will be made to convert it to one.
*
* Results:
* The return value is normally TCL_OK. If listPtr does not refer to a
* list object and can not be converted to one, TCL_ERROR is returned and
* an error message will be left in the interpreter's result if interp is
* not NULL.
*
* Side effects:
* The ref counts of the objc elements in objv are incremented since the
* resulting list now refers to them. Similarly, the ref counts for
* replaced objects are decremented. listObj is converted, if necessary,
* to a list object. listObj's old string representation, if any, is
* freed.
*
*----------------------------------------------------------------------
*/
int
Tcl_ListObjReplace(
Tcl_Interp *interp, /* Used for error reporting if not NULL. */
Tcl_Obj *listObj, /* List object whose elements to replace. */
Tcl_Size first, /* Index of first element to replace. */
Tcl_Size numToDelete, /* Number of elements to replace. */
Tcl_Size numToInsert, /* Number of objects to insert. */
Tcl_Obj *const insertObjs[])/* Tcl objects to insert */
{
ListRep listRep;
Tcl_Size origListLen;
ptrdiff_t lenChange;
ptrdiff_t leadSegmentLen;
ptrdiff_t tailSegmentLen;
Tcl_Size numFreeSlots;
ptrdiff_t leadShift;
ptrdiff_t tailShift;
Tcl_Obj **listObjs;
int favor;
if (Tcl_IsShared(listObj)) {
Tcl_Panic("%s called with shared object", "Tcl_ListObjReplace");
}
if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK)
return TCL_ERROR; /* Cannot be converted to a list */
/* TODO - will need modification if Tcl9 sticks to unsigned indices */
/* Make limits sane */
origListLen = ListRepLength(&listRep);
if (first < 0) {
first = 0;
}
if (first > origListLen) {
first = origListLen; /* So we'll insert after last element. */
}
if (numToDelete < 0) {
numToDelete = 0;
} else if (first > ListSizeT_MAX - numToDelete /* Handle integer overflow */
|| origListLen < first + numToDelete) {
numToDelete = origListLen - first;
}
if (numToInsert > ListSizeT_MAX - (origListLen - numToDelete)) {
return ListLimitExceededError(interp);
}
if ((first+numToDelete) >= origListLen) {
/* Operating at back of list. Favor leaving space at back */
favor = LISTREP_SPACE_FAVOR_BACK;
} else if (first == 0) {
/* Operating on front of list. Favor leaving space in front */
favor = LISTREP_SPACE_FAVOR_FRONT;
} else {
/* Operating on middle of list. */
favor = LISTREP_SPACE_FAVOR_NONE;
}
/*
* There are a number of special cases to consider from an optimization
* point of view.
* (1) Pure deletes (numToInsert==0) from the front or back can be treated
* as a range op irrespective of whether the ListStore is shared or not
* (2) Pure inserts (numToDelete == 0)
* (2a) Pure inserts at the back can be treated as appends
* (2b) Pure inserts from the *front* can be optimized under certain
* conditions by inserting before first ListStore slot in use if there
* is room, again irrespective of sharing
* (3) If the ListStore is shared OR there is insufficient free space
* OR existing allocation is too large compared to new size, create
* a new ListStore
* (4) Unshared ListStore with sufficient free space. Delete, shift and
* insert within the ListStore.
*/
/* Note: do not do TclInvalidateStringRep as yet in case there are errors */
/* Check Case (1) - Treat pure deletes from front or back as range ops */
if (numToInsert == 0) {
if (numToDelete == 0) {
/*
* Should force canonical even for no-op. Remember Tcl_Obj unshared
* so OK to invalidate string rep
*/
/* T:listrep-1.10,2.8 */
TclInvalidateStringRep(listObj);
return TCL_OK;
}
if (first == 0) {
/* Delete from front, so return tail. */
/* T:listrep-1.{4,5},2.{4,5},3.{15,16},4.7 */
ListRep tailRep;
ListRepRange(&listRep, numToDelete, origListLen-1, 0, &tailRep);
ListObjReplaceRepAndInvalidate(listObj, &tailRep);
return TCL_OK;
} else if ((first+numToDelete) >= origListLen) {
/* Delete from tail, so return head */
/* T:listrep-1.{8,9},2.{6,7},3.{17,18},4.8 */
ListRep headRep;
ListRepRange(&listRep, 0, first-1, 0, &headRep);
ListObjReplaceRepAndInvalidate(listObj, &headRep);
return TCL_OK;
}
/* Deletion from middle. Fall through to general case */
}
/* Garbage collect before checking the pure insert optimization */
ListRepFreeUnreferenced(&listRep);
/*
* Check Case (2) - pure inserts under certain conditions:
*/
if (numToDelete == 0) {
/* Case (2a) - Append to list. */
if (first == origListLen) {
/* T:listrep-1.11,2.9,3.{5,6},2.2.1 */
return TclListObjAppendElements(
interp, listObj, numToInsert, insertObjs);
}
/*
* Case (2b) - pure inserts at front under some circumstances
* (i) Insertion must be at head of list
* (ii) The list's span must be at head of the in-use slots in the store
* (iii) There must be unused room at front of the store
* NOTE THIS IS TRUE EVEN IF THE ListStore IS SHARED as it will not
* affect the other Tcl_Obj's referencing this ListStore.
*/
if (first == 0 && /* (i) */
ListRepStart(&listRep) == listRep.storePtr->firstUsed && /* (ii) */
numToInsert <= listRep.storePtr->firstUsed /* (iii) */
) {
Tcl_Size newLen;
LIST_ASSERT(numToInsert); /* Else would have returned above */
listRep.storePtr->firstUsed -= numToInsert;
ObjArrayCopy(&listRep.storePtr->slots[listRep.storePtr->firstUsed],
numToInsert,
insertObjs);
listRep.storePtr->numUsed += numToInsert;
newLen = listRep.spanPtr->spanLength + numToInsert;
if (listRep.spanPtr && listRep.spanPtr->refCount <= 1) {
/* An unshared span record, re-use it */
/* T:listrep-3.1 */
listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
listRep.spanPtr->spanLength = newLen;
} else {
/* Need a new span record */
if (listRep.storePtr->firstUsed == 0) {
listRep.spanPtr = NULL;
} else {
/* T:listrep-4.3 */
listRep.spanPtr =
ListSpanNew(listRep.storePtr->firstUsed, newLen);
}
}
ListObjReplaceRepAndInvalidate(listObj, &listRep);
return TCL_OK;
}
}
/* Just for readability of the code */
lenChange = numToInsert - numToDelete;
leadSegmentLen = first;
tailSegmentLen = origListLen - (first + numToDelete);
numFreeSlots = listRep.storePtr->numAllocated - listRep.storePtr->numUsed;
/*
* Before further processing, if unshared, try and reallocate to avoid
* new allocation below. This avoids expensive ref count manipulation
* later by not having to go through the ListRepInit and
* ListObjReplaceAndInvalidate below.
* TODO - we could be smarter about the reallocate. Use of realloc
* means all new free space is at the back. Instead, the realloc could
* be an explicit alloc and memmove which would let us redistribute
* free space.
*/
if ((ptrdiff_t)numFreeSlots < lenChange && !ListRepIsShared(&listRep)) {
/* T:listrep-1.{1,3,14,18,21},3.{3,10,11,14,27,32,41} */
ListStore *newStorePtr =
ListStoreReallocate(listRep.storePtr, origListLen + lenChange);
if (newStorePtr == NULL) {
return MemoryAllocationError(interp,
LIST_SIZE(origListLen + lenChange));
}
listRep.storePtr = newStorePtr;
numFreeSlots =
listRep.storePtr->numAllocated - listRep.storePtr->numUsed;
/*
* WARNING: at this point the Tcl_Obj internal rep potentially
* points to freed storage if the reallocation returned a
* different location. Overwrite it to bring it back in sync.
*/
ListObjStompRep(listObj, &listRep);
}
/*
* Case (3) a new ListStore is required
* (a) The passed-in ListStore is shared
* (b) There is not enough free space in the unshared passed-in ListStore
* (c) The new unshared size is much "smaller" (TODO) than the allocated space
* TODO - for unshared case ONLY, consider a "move" based implementation
*/
if (ListRepIsShared(&listRep) || /* 3a */
(ptrdiff_t)numFreeSlots < lenChange || /* 3b */
(origListLen + lenChange) < (listRep.storePtr->numAllocated / 4) /* 3c */
) {
ListRep newRep;
Tcl_Obj **toObjs;
listObjs = &listRep.storePtr->slots[ListRepStart(&listRep)];
ListRepInit(origListLen + lenChange,
NULL,
LISTREP_PANIC_ON_FAIL | favor,
&newRep);
toObjs = ListRepSlotPtr(&newRep, 0);
if (leadSegmentLen > 0) {
/* T:listrep-2.{2,3,13:18},4.{6,9,13:18} */
ObjArrayCopy(toObjs, leadSegmentLen, listObjs);
}
if (numToInsert > 0) {
/* T:listrep-2.{1,2,3,10:18},4.{1,2,4,6,10:18} */
ObjArrayCopy(&toObjs[leadSegmentLen],
numToInsert,
insertObjs);
}
if (tailSegmentLen > 0) {
/* T:listrep-2.{1,2,3,10:15},4.{1,2,4,6,9:12,16:18} */
ObjArrayCopy(&toObjs[leadSegmentLen + numToInsert],
tailSegmentLen,
&listObjs[leadSegmentLen+numToDelete]);
}
newRep.storePtr->numUsed = origListLen + lenChange;
if (newRep.spanPtr) {
/* T:listrep-2.{1,2,3,10:18},4.{1,2,4,6,9:18} */
newRep.spanPtr->spanLength = newRep.storePtr->numUsed;
}
LISTREP_CHECK(&newRep);
ListObjReplaceRepAndInvalidate(listObj, &newRep);
return TCL_OK;
}
/*
* Case (4) - unshared ListStore with sufficient room.
* After deleting elements, there will be a corresponding gap. If this
* gap does not match number of insertions, either the lead segment,
* or the tail segment, or both will have to be moved.
* The general strategy is to move the fewest number of elements. If
*
* TODO - what about appends to unshared ? Is below sufficiently optimal?
*/
/* Following must hold for unshared listreps after ListRepFreeUnreferenced above */
LIST_ASSERT(origListLen == listRep.storePtr->numUsed);
LIST_ASSERT(origListLen == ListRepLength(&listRep));
LIST_ASSERT(ListRepStart(&listRep) == listRep.storePtr->firstUsed);
LIST_ASSERT((numToDelete + numToInsert) > 0);
/* Base of slot array holding the list elements */
listObjs = &listRep.storePtr->slots[ListRepStart(&listRep)];
/*
* Free up elements to be deleted. Before that, increment the ref counts
* for objects to be inserted in case there is overlap. T:listobj-11.1
*/
if (numToInsert) {
/* T:listrep-1.{1,3,12:21},3.{2,3,7:14,23:41} */
ObjArrayIncrRefs(insertObjs, 0, numToInsert);
}
if (numToDelete) {
/* T:listrep-1.{6,7,12:21},3.{19:41} */
ObjArrayDecrRefs(listObjs, first, numToDelete);
}
/*
* TODO - below the moves are optimized but this may result in needing a
* span allocation. Perhaps for small lists, it may be more efficient to
* just move everything up front and save on allocating a span.
*/
/*
* Calculate shifts if necessary to accommodate insertions.
* NOTE: all indices are relative to listObjs which is not necessarily the
* start of the ListStore storage area.
*
* leadShift - how much to shift the lead segment
* tailShift - how much to shift the tail segment
* insertTarget - index where to insert.
*/
if (lenChange == 0) {
/* T:listrep-1.{12,15,19},3.{23,28,33}. Exact fit */
leadShift = 0;
tailShift = 0;
} else if (lenChange < 0) {
/*
* More deletions than insertions. The gap after deletions is large
* enough for insertions. Move a segment depending on size.
*/
if (leadSegmentLen > tailSegmentLen) {
/* Tail segment smaller. Insert after lead, move tail down */
/* T:listrep-1.{7,17,20},3.{21,2229,35} */
leadShift = 0;
tailShift = lenChange;
} else {
/* Lead segment smaller. Insert before tail, move lead up */
/* T:listrep-1.{6,13,16},3.{19,20,24,34} */
leadShift = -lenChange;
tailShift = 0;
}
} else {
LIST_ASSERT(lenChange > 0); /* Reminder */
/*
* We need to make room for the insertions. Again we have multiple
* possibilities. We may be able to get by just shifting one segment
* or need to shift both. In the former case, favor shifting the
* smaller segment.
*/
ptrdiff_t leadSpace = ListRepNumFreeHead(&listRep);
ptrdiff_t tailSpace = ListRepNumFreeTail(&listRep);
ptrdiff_t finalFreeSpace = leadSpace + tailSpace - lenChange;
LIST_ASSERT((leadSpace + tailSpace) >= lenChange);
if (leadSpace >= lenChange
&& (leadSegmentLen < tailSegmentLen || tailSpace < lenChange)) {
/* Move only lead to the front to make more room */
/* T:listrep-3.25,36,38, */
leadShift = -lenChange;
tailShift = 0;
/*
* Redistribute the remaining free space between the front and
* back if either there is no tail space left or if the
* entire list is the head anyways. This is an important
* optimization for further operations like further asymmetric
* insertions.
*/
if (finalFreeSpace > 1 && (tailSpace == 0 || tailSegmentLen == 0)) {
ptrdiff_t postShiftLeadSpace = leadSpace - lenChange;
if (postShiftLeadSpace > (finalFreeSpace/2)) {
Tcl_Size extraShift = postShiftLeadSpace - (finalFreeSpace / 2);
leadShift -= extraShift;
tailShift = -extraShift; /* Move tail to the front as well */
}
} /* else T:listrep-3.{7,12,25,38} */
LIST_ASSERT(leadShift >= 0 || leadSpace >= -leadShift);
} else if (tailSpace >= lenChange) {
/* Move only tail segment to the back to make more room. */
/* T:listrep-3.{8,10,11,14,26,27,30,32,37,39,41} */
leadShift = 0;
tailShift = lenChange;
/*
* See comments above. This is analogous.
*/
if (finalFreeSpace > 1 && (leadSpace == 0 || leadSegmentLen == 0)) {
ptrdiff_t postShiftTailSpace = tailSpace - lenChange;
if (postShiftTailSpace > (finalFreeSpace/2)) {
/* T:listrep-1.{1,3,14,18,21},3.{2,3,26,27} */
Tcl_Size extraShift = postShiftTailSpace - (finalFreeSpace / 2);
tailShift += extraShift;
leadShift = extraShift; /* Move head to the back as well */
}
}
LIST_ASSERT(tailShift <= tailSpace);
} else {
/*
* Both lead and tail need to be shifted to make room.
* Divide remaining free space equally between front and back.
*/
/* T:listrep-3.{9,13,31,40} */
LIST_ASSERT(leadSpace < lenChange);
LIST_ASSERT(tailSpace < lenChange);
/*
* leadShift = leadSpace - (finalFreeSpace/2)
* Thus leadShift <= leadSpace
* Also,
* = leadSpace - (leadSpace + tailSpace - lenChange)/2
* = leadSpace/2 - tailSpace/2 + lenChange/2
* >= 0 because lenChange > tailSpace
*/
leadShift = leadSpace - (finalFreeSpace / 2);
tailShift = lenChange - leadShift;
if (tailShift > tailSpace) {
/* Account for integer division errors */
leadShift += 1;
tailShift -= 1;
}
/*
* Following must be true because otherwise one of the previous
* if clauses would have been taken.
*/
LIST_ASSERT(leadShift > 0 && leadShift < lenChange);
LIST_ASSERT(tailShift > 0 && tailShift < lenChange);
leadShift = -leadShift; /* Lead is actually shifted downward */
}
}
/* Careful about order of moves! */
if (leadShift > 0) {
/* Will happen when we have to make room at bottom */
if (tailShift != 0 && tailSegmentLen != 0) {
/* T:listrep-1.{1,3,14,18},3.{2,3,26,27} */
Tcl_Size tailStart = leadSegmentLen + numToDelete;
memmove(&listObjs[tailStart + tailShift],
&listObjs[tailStart],
tailSegmentLen * sizeof(Tcl_Obj *));
}
if (leadSegmentLen != 0) {
/* T:listrep-1.{3,6,16,18,21},3.{19,20,34} */
memmove(&listObjs[leadShift],
&listObjs[0],
leadSegmentLen * sizeof(Tcl_Obj *));
}
} else {
if (leadShift != 0 && leadSegmentLen != 0) {
/* T:listrep-3.{7,9,12,13,31,36,38,40} */
memmove(&listObjs[leadShift],
&listObjs[0],
leadSegmentLen * sizeof(Tcl_Obj *));
}
if (tailShift != 0 && tailSegmentLen != 0) {
/* T:listrep-1.{7,17},3.{8:11,13,14,21,22,35,37,39:41} */
Tcl_Size tailStart = leadSegmentLen + numToDelete;
memmove(&listObjs[tailStart + tailShift],
&listObjs[tailStart],
tailSegmentLen * sizeof(Tcl_Obj *));
}
}
if (numToInsert) {
/* Do NOT use ObjArrayCopy here since we have already incr'ed ref counts */
/* T:listrep-1.{1,3,12:21},3.{2,3,7:14,23:41} */
memmove(&listObjs[leadSegmentLen + leadShift],
insertObjs,
numToInsert * sizeof(Tcl_Obj *));
}
listRep.storePtr->firstUsed += leadShift;
listRep.storePtr->numUsed = origListLen + lenChange;
listRep.storePtr->flags = 0;
if (listRep.spanPtr && listRep.spanPtr->refCount <= 1) {
/* An unshared span record, re-use it, even if not required */
/* T:listrep-3.{2,3,7:14},3.{19:41} */
listRep.spanPtr->spanStart = listRep.storePtr->firstUsed;
listRep.spanPtr->spanLength = listRep.storePtr->numUsed;
} else {
/* Need a new span record */
if (listRep.storePtr->firstUsed == 0) {
/* T:listrep-1.{7,12,15,17,19,20} */
listRep.spanPtr = NULL;
} else {
/* T:listrep-1.{1,3,6.1,13,14,16,18,21} */
listRep.spanPtr = ListSpanNew(listRep.storePtr->firstUsed,
listRep.storePtr->numUsed);
}
}
LISTREP_CHECK(&listRep);
ListObjReplaceRepAndInvalidate(listObj, &listRep);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* TclLindexList --
*
* This procedure handles the 'lindex' command when objc==3.
*
* Results:
* Returns a pointer to the object extracted, or NULL if an error
* occurred. The returned object already includes one reference count for
* the pointer returned.
*
* Side effects:
* None.
*
* Notes:
* This procedure is implemented entirely as a wrapper around
* TclLindexFlat. All it does is reconfigure the argument format into the
* form required by TclLindexFlat, while taking care to manage shimmering
* in such a way that we tend to keep the most useful internalreps and/or
* avoid the most expensive conversions.
*
*----------------------------------------------------------------------
*/
Tcl_Obj *
TclLindexList(
Tcl_Interp *interp, /* Tcl interpreter. */
Tcl_Obj *listObj, /* List being unpacked. */
Tcl_Obj *argObj) /* Index or index list. */
{
Tcl_Size index; /* Index into the list. */
Tcl_Obj *indexListCopy;
Tcl_Obj **indexObjs;
Tcl_Size numIndexObjs;
/*
* Determine whether argPtr designates a list or a single index. We have
* to be careful about the order of the checks to avoid repeated
* shimmering; if internal rep is already a list do not shimmer it.
* see TIP#22 and TIP#33 for the details.
*/
if (!TclHasInternalRep(argObj, &tclListType.objType)
&& TclGetIntForIndexM(NULL, argObj, ListSizeT_MAX - 1, &index)
== TCL_OK) {
/*
* argPtr designates a single index.
*/
return TclLindexFlat(interp, listObj, 1, &argObj);
}
/*
* Here we make a private copy of the index list argument to avoid any
* shimmering issues that might invalidate the indices array below while
* we are still using it. This is probably unnecessary. It does not appear
* that any damaging shimmering is possible, and no test has been devised
* to show any error when this private copy is not made. But it's cheap,
* and it offers some future-proofing insurance in case the TclLindexFlat
* implementation changes in some unexpected way, or some new form of
* trace or callback permits things to happen that the current
* implementation does not.
*/
indexListCopy = TclListObjCopy(NULL, argObj);
if (indexListCopy == NULL) {
/*
* The argument is neither an index nor a well-formed list.
* Report the error via TclLindexFlat.
* TODO - This is as original. why not directly return an error?
*/
return TclLindexFlat(interp, listObj, 1, &argObj);
}
ListObjGetElements(indexListCopy, numIndexObjs, indexObjs);
listObj = TclLindexFlat(interp, listObj, numIndexObjs, indexObjs);
Tcl_DecrRefCount(indexListCopy);
return listObj;
}
/*
*----------------------------------------------------------------------
*
* TclLindexFlat --
*
* This procedure is the core of the 'lindex' command, with all index
* arguments presented as a flat list.
*
* Results:
* Returns a pointer to the object extracted, or NULL if an error
* occurred. The returned object already includes one reference count for
* the pointer returned.
*
* Side effects:
* None.
*
* Notes:
* The reference count of the returned object includes one reference
* corresponding to the pointer returned. Thus, the calling code will
* usually do something like:
* Tcl_SetObjResult(interp, result);
* Tcl_DecrRefCount(result);
*
*----------------------------------------------------------------------
*/
Tcl_Obj *
TclLindexFlat(
Tcl_Interp *interp, /* Tcl interpreter. */
Tcl_Obj *listObj, /* Tcl object representing the list. */
Tcl_Size indexCount, /* Count of indices. */
Tcl_Obj *const indexArray[])/* Array of pointers to Tcl objects that
* represent the indices in the list. */
{
Tcl_Size i;
/* Handle ArithSeries as special case */
if (TclHasInternalRep(listObj,&tclArithSeriesType.objType)) {
Tcl_Size listLen = ABSTRACTLIST_PROC(listObj, lengthProc)(listObj);
Tcl_Size index;
Tcl_Obj *elemObj = NULL;
for (i=0 ; i<indexCount && listObj ; i++) {
if (TclGetIntForIndexM(interp, indexArray[i], /*endValue*/ listLen-1,
&index) == TCL_OK) {
}
if (i==0) {
elemObj = TclArithSeriesObjIndex(NULL, listObj, index);
} else if (index > 0) {
/* ArithSeries cannot be a list of lists */
Tcl_DecrRefCount(elemObj);
TclNewObj(elemObj);
break;
}
}
Tcl_IncrRefCount(elemObj);
return elemObj;
}
Tcl_IncrRefCount(listObj);
for (i=0 ; i<indexCount && listObj ; i++) {
Tcl_Size index, listLen = 0;
Tcl_Obj **elemPtrs = NULL, *sublistCopy;
/*
* Here we make a private copy of the current sublist, so we avoid any
* shimmering issues that might invalidate the elemPtr array below
* while we are still using it. See test lindex-8.4.
*/
sublistCopy = TclListObjCopy(interp, listObj);
Tcl_DecrRefCount(listObj);
listObj = NULL;
if (sublistCopy == NULL) {
/* The sublist is not a list at all => error. */
break;
}
LIST_ASSERT_TYPE(sublistCopy);
ListObjGetElements(sublistCopy, listLen, elemPtrs);
if (TclGetIntForIndexM(interp, indexArray[i], /*endValue*/ listLen-1,
&index) == TCL_OK) {
if (index < 0 || index >= listLen) {
/*
* Index is out of range. Break out of loop with empty result.
* First check remaining indices for validity
*/
while (++i < indexCount) {
if (TclGetIntForIndexM(
interp, indexArray[i], ListSizeT_MAX - 1, &index)
!= TCL_OK) {
Tcl_DecrRefCount(sublistCopy);
return NULL;
}
}
TclNewObj(listObj);
} else {
/* Extract the pointer to the appropriate element. */
listObj = elemPtrs[index];
}
Tcl_IncrRefCount(listObj);
}
Tcl_DecrRefCount(sublistCopy);
}
return listObj;
}
/*
*----------------------------------------------------------------------
*
* TclLsetList --
*
* Core of the 'lset' command when objc == 4. Objv[2] may be either a
* scalar index or a list of indices.
* It also handles 'lpop' when given a NULL value.
*
* Results:
* Returns the new value of the list variable, or NULL if there was an
* error. The returned object includes one reference count for the
* pointer returned.
*
* Side effects:
* None.
*
* Notes:
* This procedure is implemented entirely as a wrapper around
* TclLsetFlat. All it does is reconfigure the argument format into the
* form required by TclLsetFlat, while taking care to manage shimmering
* in such a way that we tend to keep the most useful internalreps and/or
* avoid the most expensive conversions.
*
*----------------------------------------------------------------------
*/
Tcl_Obj *
TclLsetList(
Tcl_Interp *interp, /* Tcl interpreter. */
Tcl_Obj *listObj, /* Pointer to the list being modified. */
Tcl_Obj *indexArgObj, /* Index or index-list arg to 'lset'. */
Tcl_Obj *valueObj) /* Value arg to 'lset' or NULL to 'lpop'. */
{
Tcl_Size indexCount = 0; /* Number of indices in the index list. */
Tcl_Obj **indices = NULL; /* Vector of indices in the index list. */
Tcl_Obj *retValueObj; /* Pointer to the list to be returned. */
Tcl_Size index; /* Current index in the list - discarded. */
Tcl_Obj *indexListCopy;
/*
* Determine whether the index arg designates a list or a single index.
* We have to be careful about the order of the checks to avoid repeated
* shimmering; see TIP #22 and #23 for details.
*/
if (!TclHasInternalRep(indexArgObj, &tclListType.objType)
&& TclGetIntForIndexM(NULL, indexArgObj, ListSizeT_MAX - 1, &index)
== TCL_OK) {
/* indexArgPtr designates a single index. */
/* T:listrep-1.{2.1,12.1,15.1,19.1},2.{2.3,9.3,10.1,13.1,16.1}, 3.{4,5,6}.3 */
return TclLsetFlat(interp, listObj, 1, &indexArgObj, valueObj);
}
indexListCopy = TclListObjCopy(NULL, indexArgObj);
if (indexListCopy == NULL) {
/*
* indexArgPtr designates something that is neither an index nor a
* well formed list. Report the error via TclLsetFlat.
*/
return TclLsetFlat(interp, listObj, 1, &indexArgObj, valueObj);
}
LIST_ASSERT_TYPE(indexListCopy);
ListObjGetElements(indexListCopy, indexCount, indices);
/*
* Let TclLsetFlat perform the actual lset operation.
*/
retValueObj = TclLsetFlat(interp, listObj, indexCount, indices, valueObj);
Tcl_DecrRefCount(indexListCopy);
return retValueObj;
}
/*
*----------------------------------------------------------------------
*
* TclLsetFlat --
*
* Core engine of the 'lset' command.
* It also handles 'lpop' when given a NULL value.
*
* Results:
* Returns the new value of the list variable, or NULL if an error
* occurred. The returned object includes one reference count for the
* pointer returned.
*
* Side effects:
* On entry, the reference count of the variable value does not reflect
* any references held on the stack. The first action of this function is
* to determine whether the object is shared, and to duplicate it if it
* is. The reference count of the duplicate is incremented. At this
* point, the reference count will be 1 for either case, so that the
* object will appear to be unshared.
*
* If an error occurs, and the object has been duplicated, the reference
* count on the duplicate is decremented so that it is now 0: this
* dismisses any memory that was allocated by this function.
*
* If no error occurs, the reference count of the original object is
* incremented if the object has not been duplicated, and nothing is done
* to a reference count of the duplicate. Now the reference count of an
* unduplicated object is 2 (the returned pointer, plus the one stored in
* the variable). The reference count of a duplicate object is 1,
* reflecting that the returned pointer is the only active reference. The
* caller is expected to store the returned value back in the variable
* and decrement its reference count. (INST_STORE_* does exactly this.)
*
*----------------------------------------------------------------------
*/
Tcl_Obj *
TclLsetFlat(
Tcl_Interp *interp, /* Tcl interpreter. */
Tcl_Obj *listObj, /* Pointer to the list being modified. */
Tcl_Size indexCount, /* Number of index args. */
Tcl_Obj *const indexArray[],
/* Index args. */
Tcl_Obj *valueObj) /* Value arg to 'lset' or NULL to 'lpop'. */
{
Tcl_Size index, len;
int result;
Tcl_Obj *subListObj, *retValueObj;
Tcl_Obj *pendingInvalidates[10];
Tcl_Obj **pendingInvalidatesPtr = pendingInvalidates;
Tcl_Size numPendingInvalidates = 0;
/*
* If there are no indices, simply return the new value. (Without
* indices, [lset] is a synonym for [set].
* [lpop] does not use this but protect for NULL valueObj just in case.
*/
if (indexCount == 0) {
if (valueObj != NULL) {
Tcl_IncrRefCount(valueObj);
}
return valueObj;
}
/*
* If the list is shared, make a copy we can modify (copy-on-write). We
* use Tcl_DuplicateObj() instead of TclListObjCopy() for a few reasons:
* 1) we have not yet confirmed listObj is actually a list; 2) We make a
* verbatim copy of any existing string rep, and when we combine that with
* the delayed invalidation of string reps of modified Tcl_Obj's
* implemented below, the outcome is that any error condition that causes
* this routine to return NULL, will leave the string rep of listObj and
* all elements to be unchanged.
*/
subListObj = Tcl_IsShared(listObj) ? Tcl_DuplicateObj(listObj) : listObj;
/*
* Anchor the linked list of Tcl_Obj's whose string reps must be
* invalidated if the operation succeeds.
*/
retValueObj = subListObj;
result = TCL_OK;
/* Allocate if static array for pending invalidations is too small */
if (indexCount
> (int) (sizeof(pendingInvalidates) / sizeof(pendingInvalidates[0]))) {
pendingInvalidatesPtr =
(Tcl_Obj **) Tcl_Alloc(indexCount * sizeof(*pendingInvalidatesPtr));
}
/*
* Loop through all the index arguments, and for each one dive into the
* appropriate sublist.
*/
do {
Tcl_Size elemCount;
Tcl_Obj *parentList, **elemPtrs;
/*
* Check for the possible error conditions...
*/
if (TclListObjGetElementsM(interp, subListObj, &elemCount, &elemPtrs)
!= TCL_OK) {
/* ...the sublist we're indexing into isn't a list at all. */
result = TCL_ERROR;
break;
}
/*
* WARNING: the macro TclGetIntForIndexM is not safe for
* post-increments, avoid '*indexArray++' here.
*/
if (TclGetIntForIndexM(interp, *indexArray, elemCount - 1, &index)
!= TCL_OK) {
/* ...the index we're trying to use isn't an index at all. */
result = TCL_ERROR;
indexArray++; /* Why bother with this increment? TBD */
break;
}
indexArray++;
if (index < 0 || index > elemCount
|| (valueObj == NULL && index >= elemCount)) {
/* ...the index points outside the sublist. */
if (interp != NULL) {
Tcl_SetObjResult(interp,
Tcl_ObjPrintf("index \"%s\" out of range",
Tcl_GetString(indexArray[-1])));
Tcl_SetErrorCode(interp,
"TCL",
"VALUE",
"INDEX"
"OUTOFRANGE",
NULL);
}
result = TCL_ERROR;
break;
}
/*
* No error conditions. As long as we're not yet on the last index,
* determine the next sublist for the next pass through the loop,
* and take steps to make sure it is an unshared copy, as we intend
* to modify it.
*/
if (--indexCount) {
parentList = subListObj;
if (index == elemCount) {
TclNewObj(subListObj);
} else {
subListObj = elemPtrs[index];
}
if (Tcl_IsShared(subListObj)) {
subListObj = Tcl_DuplicateObj(subListObj);
}
/*
* Replace the original elemPtr[index] in parentList with a copy
* we know to be unshared. This call will also deal with the
* situation where parentList shares its internalrep with other
* Tcl_Obj's. Dealing with the shared internalrep case can
* cause subListObj to become shared again, so detect that case
* and make and store another copy.
*/
if (index == elemCount) {
Tcl_ListObjAppendElement(NULL, parentList, subListObj);
} else {
TclListObjSetElement(NULL, parentList, index, subListObj);
}
if (Tcl_IsShared(subListObj)) {
subListObj = Tcl_DuplicateObj(subListObj);
TclListObjSetElement(NULL, parentList, index, subListObj);
}
/*
* The TclListObjSetElement() calls do not spoil the string rep
* of parentList, and that's fine for now, since all we've done
* so far is replace a list element with an unshared copy. The
* list value remains the same, so the string rep. is still
* valid, and unchanged, which is good because if this whole
* routine returns NULL, we'd like to leave no change to the
* value of the lset variable. Later on, when we set valueObj
* in its proper place, then all containing lists will have
* their values changed, and will need their string reps
* spoiled. We maintain a list of all those Tcl_Obj's (via a
* little internalrep surgery) so we can spoil them at that
* time.
*/
pendingInvalidatesPtr[numPendingInvalidates] = parentList;
++numPendingInvalidates;
}
} while (indexCount > 0);
/*
* Either we've detected and error condition, and exited the loop with
* result == TCL_ERROR, or we've successfully reached the last index, and
* we're ready to store valueObj. On success, we need to invalidate
* the string representations of intermediate lists whose contained
* list element would have changed.
*/
if (result == TCL_OK) {
while (numPendingInvalidates > 0) {
Tcl_Obj *objPtr;
--numPendingInvalidates;
objPtr = pendingInvalidatesPtr[numPendingInvalidates];
if (result == TCL_OK) {
/*
* We're going to store valueObj, so spoil string reps of all
* containing lists.
* TODO - historically, the storing of the internal rep was done
* because the ptr2 field of the internal rep was used to chain
* objects whose string rep needed to be invalidated. Now this
* is no longer the case, so replacing of the internal rep
* should not be needed. The TclInvalidateStringRep should
* suffice. Formulate a test case before changing.
*/
ListRep objInternalRep;
TclListObjGetRep(NULL, objPtr, &objInternalRep);
ListObjReplaceRepAndInvalidate(objPtr, &objInternalRep);
}
}
}
if (pendingInvalidatesPtr != pendingInvalidates)
Tcl_Free(pendingInvalidatesPtr);
if (result != TCL_OK) {
/*
* Error return; message is already in interp. Clean up any excess
* memory.
*/
if (retValueObj != listObj) {
Tcl_DecrRefCount(retValueObj);
}
return NULL;
}
/*
* Store valueObj in proper sublist and return. The -1 is to avoid a
* compiler warning (not a problem because we checked that we have a
* proper list - or something convertible to one - above).
*/
len = -1;
TclListObjLengthM(NULL, subListObj, &len);
if (valueObj == NULL) {
/* T:listrep-1.{4.2,5.4,6.1,7.1,8.3},2.{4,5}.4 */
Tcl_ListObjReplace(NULL, subListObj, index, 1, 0, NULL);
} else if (index == len) {
/* T:listrep-1.2.1,2.{2.3,9.3},3.{4,5,6}.3 */
Tcl_ListObjAppendElement(NULL, subListObj, valueObj);
} else {
/* T:listrep-1.{12.1,15.1,19.1},2.{10,13,16}.1 */
TclListObjSetElement(NULL, subListObj, index, valueObj);
TclInvalidateStringRep(subListObj);
}
Tcl_IncrRefCount(retValueObj);
return retValueObj;
}
/*
*----------------------------------------------------------------------
*
* TclListObjSetElement --
*
* Set a single element of a list to a specified value
*
* Results:
* The return value is normally TCL_OK. If listObj does not refer to a
* list object and cannot be converted to one, TCL_ERROR is returned and
* an error message will be left in the interpreter result if interp is
* not NULL. Similarly, if index designates an element outside the range
* [0..listLength-1], where listLength is the count of elements in the
* list object designated by listObj, TCL_ERROR is returned and an error
* message is left in the interpreter result.
*
* Side effects:
* Tcl_Panic if listObj designates a shared object. Otherwise, attempts
* to convert it to a list with a non-shared internal rep. Decrements the
* ref count of the object at the specified index within the list,
* replaces with the object designated by valueObj, and increments the
* ref count of the replacement object.
*
*----------------------------------------------------------------------
*/
int
TclListObjSetElement(
Tcl_Interp *interp, /* Tcl interpreter; used for error reporting
* if not NULL. */
Tcl_Obj *listObj, /* List object in which element should be
* stored. */
Tcl_Size index, /* Index of element to store. */
Tcl_Obj *valueObj) /* Tcl object to store in the designated list
* element. */
{
ListRep listRep;
Tcl_Obj **elemPtrs; /* Pointers to elements of the list. */
Tcl_Size elemCount; /* Number of elements in the list. */
/* Ensure that the listObj parameter designates an unshared list. */
if (Tcl_IsShared(listObj)) {
Tcl_Panic("%s called with shared object", "TclListObjSetElement");
}
if (TclListObjGetRep(interp, listObj, &listRep) != TCL_OK) {
return TCL_ERROR;
}
elemCount = ListRepLength(&listRep);
/* Ensure that the index is in bounds. */
if (index>=elemCount) {
if (interp != NULL) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
"index \"%" TCL_Z_MODIFIER "u\" out of range", index));
Tcl_SetErrorCode(interp, "TCL", "VALUE", "INDEX",
"OUTOFRANGE", NULL);
}
return TCL_ERROR;
}
/*
* Note - garbage collect this only AFTER checking indices above.
* Do not want to modify listrep and then not store it back in listObj.
*/
ListRepFreeUnreferenced(&listRep);
/* Replace a shared internal rep with an unshared copy */
if (listRep.storePtr->refCount > 1) {
ListRep newInternalRep;
/* T:listrep-2.{10,13,16}.1 */
/* TODO - leave extra space? */
ListRepClone(&listRep, &newInternalRep, LISTREP_PANIC_ON_FAIL);
listRep = newInternalRep;
} /* else T:listrep-1.{12.1,15.1,19.1} */
/* Retrieve element array AFTER potential cloning above */
ListRepElements(&listRep, elemCount, elemPtrs);
/*
* Add a reference to the new list element and remove from old before
* replacing it. Order is important!
*/
Tcl_IncrRefCount(valueObj);
Tcl_DecrRefCount(elemPtrs[index]);
elemPtrs[index] = valueObj;
/* Internal rep may be cloned so replace */
ListObjReplaceRepAndInvalidate(listObj, &listRep);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* FreeListInternalRep --
*
* Deallocate the storage associated with a list object's internal
* representation.
*
* Results:
* None.
*
* Side effects:
* Frees listPtr's List* internal representation, if no longer shared.
* May decrement the ref counts of element objects, which may free them.
*
*----------------------------------------------------------------------
*/
static void
FreeListInternalRep(
Tcl_Obj *listObj) /* List object with internal rep to free. */
{
ListRep listRep;
ListObjGetRep(listObj, &listRep);
if (listRep.storePtr->refCount-- <= 1) {
ObjArrayDecrRefs(
listRep.storePtr->slots,
listRep.storePtr->firstUsed, listRep.storePtr->numUsed);
Tcl_Free(listRep.storePtr);
}
if (listRep.spanPtr) {
ListSpanDecrRefs(listRep.spanPtr);
}
}
/*
*----------------------------------------------------------------------
*
* DupListInternalRep --
*
* Initialize the internal representation of a list Tcl_Obj to share the
* internal representation of an existing list object.
*
* Results:
* None.
*
* Side effects:
* The reference count of the List internal rep is incremented.
*
*----------------------------------------------------------------------
*/
static void
DupListInternalRep(
Tcl_Obj *srcObj, /* Object with internal rep to copy. */
Tcl_Obj *copyObj) /* Object with internal rep to set. */
{
ListRep listRep;
ListObjGetRep(srcObj, &listRep);
ListObjOverwriteRep(copyObj, &listRep);
}
/*
*----------------------------------------------------------------------
*
* SetListFromAny --
*
* Attempt to generate a list internal form for the Tcl object "objPtr".
*
* Results:
* The return value is TCL_OK or TCL_ERROR. If an error occurs during
* conversion, an error message is left in the interpreter's result
* unless "interp" is NULL.
*
* Side effects:
* If no error occurs, a list is stored as "objPtr"s internal
* representation.
*
*----------------------------------------------------------------------
*/
static int
SetListFromAny(
Tcl_Interp *interp, /* Used for error reporting if not NULL. */
Tcl_Obj *objPtr) /* The object to convert. */
{
Tcl_Obj **elemPtrs;
ListRep listRep;
/*
* Dictionaries are a special case; they have a string representation such
* that *all* valid dictionaries are valid lists. Hence we can convert
* more directly. Only do this when there's no existing string rep; if
* there is, it is the string rep that's authoritative (because it could
* describe duplicate keys).
*/
if (!TclHasStringRep(objPtr) && TclHasInternalRep(objPtr, &tclDictType)) {
Tcl_Obj *keyPtr, *valuePtr;
Tcl_DictSearch search;
int done;
Tcl_Size size;
/*
* Create the new list representation. Note that we do not need to do
* anything with the string representation as the transformation (and
* the reverse back to a dictionary) are both order-preserving. Also
* note that since we know we've got a valid dictionary (by
* representation) we also know that fetching the size of the
* dictionary or iterating over it will not fail.
*/
Tcl_DictObjSize(NULL, objPtr, &size);
/* TODO - leave space in front and/or back? */
if (ListRepInitAttempt(
interp, size > 0 ? 2 * size : 1, NULL, &listRep)
!= TCL_OK) {
return TCL_ERROR;
}
LIST_ASSERT(listRep.spanPtr == NULL); /* Guard against future changes */
LIST_ASSERT(listRep.storePtr->firstUsed == 0);
LIST_ASSERT((listRep.storePtr->flags & LISTSTORE_CANONICAL) == 0);
listRep.storePtr->numUsed = 2 * size;
/* Populate the list representation. */
elemPtrs = listRep.storePtr->slots;
Tcl_DictObjFirst(NULL, objPtr, &search, &keyPtr, &valuePtr, &done);
while (!done) {
*elemPtrs++ = keyPtr;
*elemPtrs++ = valuePtr;
Tcl_IncrRefCount(keyPtr);
Tcl_IncrRefCount(valuePtr);
Tcl_DictObjNext(&search, &keyPtr, &valuePtr, &done);
}
} else if (TclHasInternalRep(objPtr,&tclArithSeriesType.objType)) {
/*
* Convertion from Arithmetic Series is a special case
* because it can be done an order of magnitude faster
* and may occur frequently.
*/
Tcl_Size j, size = ABSTRACTLIST_PROC(objPtr, lengthProc)(objPtr);
/* TODO - leave space in front and/or back? */
if (ListRepInitAttempt(
interp, size > 0 ? size : 1, NULL, &listRep)
!= TCL_OK) {
return TCL_ERROR;
}
LIST_ASSERT(listRep.spanPtr == NULL); /* Guard against future changes */
LIST_ASSERT(listRep.storePtr->firstUsed == 0);
LIST_ASSERT((listRep.storePtr->flags & LISTSTORE_CANONICAL) == 0);
listRep.storePtr->numUsed = size;
elemPtrs = listRep.storePtr->slots;
for (j = 0; j < size; j++) {
elemPtrs[j] = TclArithSeriesObjIndex(interp, objPtr, j);
if (elemPtrs[j] == NULL) {
return TCL_ERROR;
}
}
} else {
Tcl_Size estCount, length;
const char *limit, *nextElem = Tcl_GetStringFromObj(objPtr, &length);
/*
* Allocate enough space to hold a (Tcl_Obj *) for each
* (possible) list element.
*/
estCount = TclMaxListLength(nextElem, length, &limit);
estCount += (estCount == 0); /* Smallest list struct holds 1
* element. */
/* TODO - allocate additional space? */
if (ListRepInitAttempt(interp, estCount, NULL, &listRep)
!= TCL_OK) {
return TCL_ERROR;
}
LIST_ASSERT(listRep.spanPtr == NULL); /* Guard against future changes */
LIST_ASSERT(listRep.storePtr->firstUsed == 0);
elemPtrs = listRep.storePtr->slots;
/* Each iteration, parse and store a list element. */
while (nextElem < limit) {
const char *elemStart;
char *check;
Tcl_Size elemSize;
int literal;
if (TCL_OK != TclFindElement(interp, nextElem, limit - nextElem,
&elemStart, &nextElem, &elemSize, &literal)) {
fail:
while (--elemPtrs >= listRep.storePtr->slots) {
Tcl_DecrRefCount(*elemPtrs);
}
Tcl_Free(listRep.storePtr);
return TCL_ERROR;
}
if (elemStart == limit) {
break;
}
TclNewObj(*elemPtrs);
TclInvalidateStringRep(*elemPtrs);
check = Tcl_InitStringRep(*elemPtrs, literal ? elemStart : NULL,
elemSize);
if (elemSize && check == NULL) {
MemoryAllocationError(interp, elemSize);
goto fail;
}
if (!literal) {
Tcl_InitStringRep(*elemPtrs, NULL,
TclCopyAndCollapse(elemSize, elemStart, check));
}
Tcl_IncrRefCount(*elemPtrs++);/* Since list now holds ref to it. */
}
listRep.storePtr->numUsed =
elemPtrs - listRep.storePtr->slots;
}
LISTREP_CHECK(&listRep);
/*
* Store the new internalRep. We do this as late
* as possible to allow the conversion code, in particular
* Tcl_GetStringFromObj, to use the old internalRep.
*/
/*
* Note old string representation NOT to be invalidated.
* So do NOT use ListObjReplaceRepAndInvalidate. InternalRep to be freed AFTER
* IncrRefs so do not use ListObjOverwriteRep
*/
ListRepIncrRefs(&listRep);
TclFreeInternalRep(objPtr);
objPtr->internalRep.twoPtrValue.ptr1 = listRep.storePtr;
objPtr->internalRep.twoPtrValue.ptr2 = listRep.spanPtr;
objPtr->typePtr = &tclListType.objType;
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* UpdateStringOfList --
*
* Update the string representation for a list object.
*
* Any previously-existing string representation is not invalidated, so
* storage is lost if this has not been taken care of.
*
* Effect
*
* The string representation of 'listPtr' is set to the resulting string.
* This string will be empty if the list has no elements. It is assumed
* that the list internal representation is not NULL.
*
*----------------------------------------------------------------------
*/
static void
UpdateStringOfList(
Tcl_Obj *listObj) /* List object with string rep to update. */
{
# define LOCAL_SIZE 64
char localFlags[LOCAL_SIZE], *flagPtr = NULL;
Tcl_Size numElems, i, length;
TCL_HASH_TYPE bytesNeeded = 0;
const char *elem, *start;
char *dst;
Tcl_Obj **elemPtrs;
ListRep listRep;
ListObjGetRep(listObj, &listRep);
LISTREP_CHECK(&listRep);
ListRepElements(&listRep, numElems, elemPtrs);
/*
* Mark the list as being canonical; although it will now have a string
* rep, it is one we derived through proper "canonical" quoting and so
* it's known to be free from nasties relating to [concat] and [eval].
* However, we only do this if this is not a spanned list. Marking the
* storage canonical for a spanned list make ALL lists using the storage
* canonical which is not right. (Consider a list generated from a
* string and then this function called for a spanned list generated
* from it). On the other hand, a spanned list is always canonical
* (never generated from a string) so it does not have to be explicitly
* marked as such. The ListObjIsCanonical macro takes this into account.
* See the comments there.
*/
if (listRep.spanPtr == NULL) {
LIST_ASSERT(listRep.storePtr->firstUsed == 0);/* Invariant */
listRep.storePtr->flags |= LISTSTORE_CANONICAL;
}
/* Handle empty list case first, so rest of the routine is simpler. */
if (numElems == 0) {
Tcl_InitStringRep(listObj, NULL, 0);
return;
}
/* Pass 1: estimate space, gather flags. */
if (numElems <= LOCAL_SIZE) {
flagPtr = localFlags;
} else {
/* We know numElems <= LIST_MAX, so this is safe. */
flagPtr = (char *)Tcl_Alloc(numElems);
}
for (i = 0; i < numElems; i++) {
flagPtr[i] = (i ? TCL_DONT_QUOTE_HASH : 0);
elem = Tcl_GetStringFromObj(elemPtrs[i], &length);
bytesNeeded += TclScanElement(elem, length, flagPtr+i);
if (bytesNeeded > SIZE_MAX - numElems) {
Tcl_Panic("max size for a Tcl value (%" TCL_Z_MODIFIER "u bytes) exceeded", SIZE_MAX);
}
}
bytesNeeded += numElems - 1;
/*
* Pass 2: copy into string rep buffer.
*/
start = dst = Tcl_InitStringRep(listObj, NULL, bytesNeeded);
TclOOM(dst, bytesNeeded);
for (i = 0; i < numElems; i++) {
flagPtr[i] |= (i ? TCL_DONT_QUOTE_HASH : 0);
elem = Tcl_GetStringFromObj(elemPtrs[i], &length);
dst += TclConvertElement(elem, length, dst, flagPtr[i]);
*dst++ = ' ';
}
/* Set the string length to what was actually written, the safe choice */
(void) Tcl_InitStringRep(listObj, NULL, dst - 1 - start);
if (flagPtr != localFlags) {
Tcl_Free(flagPtr);
}
}
/*
*------------------------------------------------------------------------
*
* TclListTestObj --
*
* Returns a list object with a specific internal rep and content.
* Used specifically for testing so span can be controlled explicitly.
*
* Results:
* Pointer to the Tcl_Obj containing the list.
*
* Side effects:
* None.
*
*------------------------------------------------------------------------
*/
Tcl_Obj *
TclListTestObj(size_t length, size_t leadingSpace, size_t endSpace)
{
ListRep listRep;
size_t capacity;
Tcl_Obj *listObj;
TclNewObj(listObj);
/* Only a test object so ignoring overflow checks */
capacity = length + leadingSpace + endSpace;
if (capacity == 0) {
return listObj;
}
if (capacity > LIST_MAX) {
return NULL;
}
ListRepInit(capacity, NULL, 0, &listRep);
ListStore *storePtr = listRep.storePtr;
size_t i;
for (i = 0; i < length; ++i) {
TclNewUIntObj(storePtr->slots[i + leadingSpace], i);
Tcl_IncrRefCount(storePtr->slots[i + leadingSpace]);
}
storePtr->firstUsed = leadingSpace;
storePtr->numUsed = length;
if (leadingSpace != 0) {
listRep.spanPtr = ListSpanNew(leadingSpace, length);
}
ListObjReplaceRepAndInvalidate(listObj, &listRep);
return listObj;
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/