Hiya All,

We are facing some difficulties in the behavior of TCL between the "non-bytecode" execution vs bytecode execution,
for since

Tcl_LappendObjCmd
vs.
TclCompileLappendCmd

How does TCL determine whether it's going to "compile" input or just
interpret it - and is there any way to "force" one way or the other (dynamically)
for testing purposes? For our testing, we need to force the two paths through the
interpreter for the same input to verify that the behavior is the same. For example, in some cases we see TCL take the "interpreted" path and call Tcl_LappendObjCmd, and in other cases, it bytecompiles the input and goes through the TclCompileLappendCmd path.

Sam Appleton
Ausdia Inc.

On 10/23/23 15:27, sam appleton wrote:
> Hiya All,
>
> We are facing some difficulties in the behavior of TCL between the "non-bytecode" execution vs bytecode execution,
> for since
>
> Tcl_LappendObjCmd
> vs.
> TclCompileLappendCmd
>
> How does TCL determine whether it's going to "compile" input or just
> interpret it - and is there any way to "force" one way or the other (dynamically)
> for testing purposes? For our testing, we need to force the two paths through the
> interpreter for the same input to verify that the behavior is the same. For example, in some cases we see TCL take the "interpreted" path and call Tcl_LappendObjCmd, and in other cases, it bytecompiles the input and goes through the TclCompileLappendCmd path.
>
>
> Sam Appleton
> Ausdia Inc.

Use the TCL_EVAL_DIRECT flag to Tcl_EvalObjEx() to forbid use of
bytecode.

https://www.tcl.tk/man/tcl8.6/TclLib/Eval.html

--
| Don Porter Applied and Computational Mathematics Division |
| donald.porter@nist.gov Information Technology Laboratory |
| http://math.nist.gov/~DPorter/ NIST |
|______________________________________________________________________|

At a script level, I believe the following three cases are necessary to
exercise all code paths. Using lappend as an example

1. Compiled with a local variable table (or use apply instead of
defining a proc)
proc testlappend {} {
lappend L a b c
} testlappend

2. Compiled without a local variable table
lappend L a b c

3. Uncompiled
set testcmd lappend
$testcmd L a b c

Corrections from Tcl bytecode gurus welcome

/Ashok

On 10/24/2023 12:57 AM, sam appleton wrote:
> Hiya All,
>
> We are facing some difficulties in the behavior of TCL between the "non-bytecode" execution vs bytecode execution,
> for since
>
> Tcl_LappendObjCmd
> vs.
> TclCompileLappendCmd
>
> How does TCL determine whether it's going to "compile" input or just
> interpret it - and is there any way to "force" one way or the other (dynamically)
> for testing purposes? For our testing, we need to force the two paths through the
> interpreter for the same input to verify that the behavior is the same. For example, in some cases we see TCL take the "interpreted" path and call Tcl_LappendObjCmd, and in other cases, it bytecompiles the input and goes through the TclCompileLappendCmd path.
>
>
> Sam Appleton
> Ausdia Inc.