tracemem(x)
untracemem(x)
retracemem(x, previous = NULL)NULL.tracemem or retracemem.NULL (invisibly).
tracemem and untracemem give errors when R is not
compiled with memory profiling; retracemem does not (so it can be
left in code during development).It is enabled in the CRAN OS X and Windows builds of R.
When an object is traced any copying of the object by the C function
duplicate produces a message to standard output, as does type
coercion and copying when passing arguments to .C or
.Fortran.
The message consists of the string tracemem, the identifying
strings for the object being copied and the new object being created,
and a stack trace showing where the duplication occurred.
retracemem() is used to indicate that a variable should be
considered a copy of a previous variable (e.g. after subscripting).
The messages can be turned off with tracingState.
It is not possible to trace functions, as this would conflict with
trace and it is not useful to trace NULL,
environments, promises, weak references, or external pointer objects, as
these are not duplicated.
These functions are primitive.
capabilities("profmem") to see if this was enabled for
this build of R.