Hello,

I'm working on making our code (which uses Tcl extensively) compile cleanly with most GCC warnings enabled and some of the issues reported are coming from tcl/tk headers.

The attached patch fixes the issues encountered from including tcl.h, which includes shadow warnings for 'index' declared on many functions and checking HAVE_DECLSPEC's value without it being set.  The patch just quells the shadow but changing the function signatures to not name the argument index (maybe call it idx) would also work.

The warning flags being cleaned up are as follows:

-W -Wall -Wundef -Wfloat-equal -Wshadow -Wunreachable-code -Winline -Wconversion

Cheers!
Sean