"Michael Gong" <mwgong@xxxxxxxxxxxxxx> writes:
> I have a file : foo.c, which is like:
>
> #line 20 "./.acc_dir/c-typeck.c"
> int main() {
>
> #line 39309 "./.acc_dir/c-typeck.c" <-- if change to 32767,
> no warning message below
> return 3;
> }
>
>
> >gcc -c foo.c -pedantic
> ./.acc_dir/c-typeck.c:22:7: warning: line number out of range.
>
>
> It seems that when the line number > 32767, which is the max of short
> int, the warning message is issued. So I assume gcc uses a short int
> to store the line number.
No. You will notice that you only get the warning with -pedantic.
gcc is warning because C89 has a limit of 32767.
> According to C99,
>
> # line digit-sequence new-line
>
> causes the implementation to behave as if the following sequence of
> source lines begins with a source line that has a line number as
> specified by the digit sequence (interpreted as a decimal
> integer). The digit sequence shall not specify zero, nor a number
> greater than 2147483647.
Yes, C99 raised the limit. If you compile with -std=c99 or
-std=gnu99, you will not get the warning. gcc defaults to gnu89 mode.
Ian
