Range checking problem - Gpc

28 Apr 2006


      The following was initially discovered by Gale Paeper.
[g5:~/gpc/testgpc/adriaan] adriaan% cat rangecheck1.p
program rangecheck1;
var i: 1..5;
begin
         i:= 5;
{$local R-}
         i:= i+1;
{$endlocal}
         i:= 4;
         i:= i+2;
         writeln( 'i = ', i);
end.
[g5:~/gpc/testgpc/adriaan] adriaan% gpc41 rangecheck1.p --range-checking
[g5:~/gpc/testgpc/adriaan] adriaan% ./a.out
i = 6
[g5:~/gpc/testgpc/adriaan] adriaan% cat rangecheck2.p
{$R+}
program rangecheck2;
var i: 1..5;
begin
         i:= 5;
{$local R-}
         i:= i+1;
{$endlocal}
         i:= 4;
         i:= i+2;
         writeln( 'i = ', i);
end.
[g5:~/gpc/testgpc/adriaan] adriaan% gpc41 rangecheck2.p --range-checking
[g5:~/gpc/testgpc/adriaan] adriaan% ./a.out
./a.out: value out of range (error #300 at 2487)
[g5:~/gpc/testgpc/adriaan] adriaan% cat rangecheck3.p
{$R+}
program rangecheck3;
var i: 1..5;
begin
         i:= 5;
{$local R-}
         i:= i+1;
{$endlocal}
         writeln( 'i = ', i);
end.
[g5:~/gpc/testgpc/adriaan] adriaan% gpc41 rangecheck3.p --range-checking
[g5:~/gpc/testgpc/adriaan] adriaan% ./a.out
i = 6
[g5:~/gpc/testgpc/adriaan] adriaan% cat rangecheck4.p
{$R+}
program rangecheck4;
var i: 1..5;
begin
         i:= 4;
         i:= i+2;
         writeln( 'i = ', i);
end.
[g5:~/gpc/testgpc/adriaan] adriaan% gpc41 rangecheck4.p --range-checking
[g5:~/gpc/testgpc/adriaan] adriaan% ./a.out
./a.out: value out of range (error #300 at 2477)
[g5:~/gpc/testgpc/adriaan] adriaan% gpc41 -v
Using built-in specs.
Configured with: ../gcc-4.1.0/configure --enable-languages=c,pascal --enable-threads=posix 
--target=powerpc-apple-darwin8 --host=powerpc-apple-darwin8 --build=powerpc-apple-darwin8 
--prefix=/Developer/Pascal/gpc410d1
Thread model: posix
gpc version 20060325, based on gcc-4.1.0
In other words, {$local R-} disables range-checking for the rest of the file when using 
--range-checking as a command-line option, not when using {$R+}. I can hardly imagine this is 
intended behaviour.
Regards,
Adriaan van Os