Re: [TCLCORE] problems with Tcl/Tk 9.0 in the Perl Tcl module

[Brian G. <bri...@ea...>]

It certainly solves to seg fault for me when I try it. It also eliminates all the compilation warnings.

Without the changes, I'm seeing these warnings:

get_elements_bug.c:15:44: warning: incompatible pointer types passing 'int *' to parameter of type 'Tcl_Size *' (aka 'long *') [-Wincompatible-pointer-types]
   15 |   char *str = Tcl_GetStringFromObj(objPtr, &len);
      |                                            ^~~~
/Users/briang42/tcl_core/usr_mac_special/include/tclDecls.h:1754:15: note: passing argument to parameter 'lengthPtr' here
 1754 |                                 Tcl_Size *lengthPtr);
      |                                           ^
get_elements_bug.c:19:46: warning: incompatible pointer types passing 'int *' to parameter of type 'Tcl_Size *' (aka 'long *') [-Wincompatible-pointer-types]
   19 |   if (Tcl_ListObjGetElements(interp, objPtr, &objc, &objv) != TCL_OK) {
      |                                              ^~~~~
/Users/briang42/tcl_core/usr_mac_special/include/tclDecls.h:1787:33: note: passing argument to parameter 'objcPtr' here
 1787 |                                 Tcl_Obj *listPtr, Tcl_Size *objcPtr,
      |                                                             ^
get_elements_bug.c:24:39: warning: format specifies type 'unsigned int' but the argument has type 'Tcl_Obj **' (aka 'struct Tcl_Obj **') [-Wformat]
   24 |   printf("objc=%d, objv=%016X\n",objc,objv);
      |                         ~~~~~         ^~~~
get_elements_bug.c:25:28: warning: format specifies type 'unsigned int' but the argument has type 'Tcl_Obj *' (aka 'struct Tcl_Obj *') [-Wformat]
   25 |   printf("objv[0]=%016X\n",objv[0]);
      |                   ~~~~~    ^~~~~~~
4 warnings generated.

With the corrections I get this result:

got string result 'fefe'
objc=1, objv=0x1308a0b78
objv[0]=0x120039020
objv[0] = 'fefe'
all done

Note: I extended the test case to go further.

YMMV.

-Brian

> On Jan 5, 2025, at 11:57, Vadim V Konovalov via Tcl-Core <tcl...@li...> wrote:
> 
> Will that change fix the segmentation fault?
>   From: Jan Nijtmans <jan...@gm...>
> Sent: Sunday, January 5, 2025 9:53 PM
> To: Коновалов Вадим Владимирович <vad...@ga...>
> Cc: Ashok Nadkarni <apn...@ya...>; Kevin Walzer <kw...@co...>; Marc Culler <cul...@gm...>; Tcl Core List <tcl...@li...>
> Subject: Re: [TCLCORE] problems with Tcl/Tk 9.0 in the Perl Tcl module
>  Op zo 5 jan 2025 om 18:44 schreef Vadim V Konovalov via:
> Here is small program to reproduce:
> ...                                                                                                                                           int objc,len;                                                                                                                                                                       In Tcl 9, this line should be:
>           Tcl_Size objc, len;
> Also, for printing pointers, please use "%p" instead of "%016X". The
> compiler should give a warning for this!
>  I don't think this is the cause of your error, but better rule
> this out first.
>  Regards,
>       Jan Nijtmans
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