how to make gcc warn about arithmetic signed overflow

[Brian Drummond]

On Sat, 2013-09-21 at 18:46 +0200, wempwer@gmail.com wrote:
> int ab = 50000;
> int bc = 50000;
> int r = ab * bc;
> 
> Is it possible for gcc to produce a
> warning in such situation?

Yes, gcc the Gnu Compiler Collection can produce such a warning:

procedure test_ovf is
   ab : integer := 50000;
   bc : integer := 50000;
   r : integer := ab * bc;
begin
   null;
end test_ovf;

gcc -c test_ovf.adb
test_ovf.adb:4:22: warning: value not in range of type
"Standard.Integer"
test_ovf.adb:4:22: warning: "Constraint_Error" will be raised at run
time
However I'm not sure it is allowed to do the same with C. 

- Brian