diff options
Diffstat (limited to 'doc/Alloc.3')
| -rw-r--r-- | doc/Alloc.3 | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/doc/Alloc.3 b/doc/Alloc.3 index e90114d..ca4f949 100644 --- a/doc/Alloc.3 +++ b/doc/Alloc.3 @@ -67,22 +67,24 @@ further allocation. \fBTcl_Realloc\fR changes the size of the block pointed to by \fIptr\fR to \fIsize\fR bytes and returns a pointer to the new block. The contents will be unchanged up to the lesser of the new and old -sizes. The returned location may be different from \fIptr\fR. +sizes. The returned location may be different from \fIptr\fR. If +\fIptr\fR is NULL, this is equivalent to calling \fBTcl_Alloc\fR with +just the \fIsize\fR argument. .PP \fBTcl_AttemptAlloc\fR and \fBTcl_AttemptRealloc\fR are identical in function to \fBTcl_Alloc\fR and \fBTcl_Realloc\fR, except that \fBTcl_AttemptAlloc\fR and \fBTcl_AttemptRealloc\fR will not cause the Tcl interpreter to \fBpanic\fR if the memory allocation fails. If the allocation fails, these functions will return NULL. Note that on some -platforms, attempting to allocate a block of memory will also cause -these functions to return NULL. +platforms, but not all, attempting to allocate a zero-sized block of +memory will also cause these functions to return NULL. .PP The procedures \fBckalloc\fR, \fBckfree\fR, \fBckrealloc\fR, \fBattemptckalloc\fR, and \fBattemptckrealloc\fR are implemented as macros. Normally, they are synonyms for the corresponding procedures documented on this page. When Tcl and all modules calling Tcl are compiled with \fBTCL_MEM_DEBUG\fR defined, however, -these macros are redefined to be special debugging versions of +these macros are redefined to be special debugging versions of these procedures. To support Tcl's memory debugging within a module, use the macros rather than direct calls to \fBTcl_Alloc\fR, etc. |