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typecast_array.c tests size_t against <0

#120

The clang compiler complains that:

In file included from psycopg/typecast.c:179:
    ./psycopg/typecast_array.c:227:31: warning: comparison of unsigned expression < 0 is always false [-Wtautological-compare]
                if (--stack_index < 0)
                    ~~~~~~~~~~~~~ ^ ~
    1 warning generated.

and indeed, it is right, size_t is unsigned, so this is never true.

    if(stack_index-- <= 0)

should do the trick.

Cheers,

mjl

Reported by Psycopg website · August 17th, 2012 @ 11:47 AM

Activity

Federico Di Gregorio
- State changed from new to open
The warning is correct but using <= instead of < would break array parsing. That test is a guard to avoid the (impossible?) case of receiving more ASCAN_END than ASCAN_BEGIN from the tokenizer. IMO, that guard can be removed.

August 17th, 2012 @ 11:58 AM
Federico Di Gregorio
- State changed from open to resolved
- Assigned user set to Federico Di Gregorio
This is better:
```
if (stack_index == 0)
    return -1;
array = stack[--stack_index];
```
and should fix the warning.
August 17th, 2012 @ 12:55 PM