Different behavior from __LINE__ macro in g++ 2.95.x and 3.x

[usenet]

On g++ version 3.X I get the "wrong" line number, 8 reported
for the following code:

1 #include <iostream>
2 using namespace std;
3 int main(void)
4 {
5 ^M^M^Mcout << "file:" << __FILE__ << " line:" << __LINE__ << endl;
6 }
7 /*
8 3 ^Ms on cout line 5 code reports
9 file:wrongLine.C line:8
10 */

where ^M denotes control-M.

Does this conform to standard? 2.95.x version's I've tried
"correctly" report 5.

Thanks in advance for your reply.

Gary

 

[Jack Klein]

On g++ version 3.X I get the "wrong" line number, 8 reported
for the following code:

1 #include <iostream>
2 using namespace std;
3 int main(void)
4 {
5 ^M^M^Mcout << "file:" << __FILE__ << " line:" << __LINE__ << endl;
6 }
7 /*
8 3 ^Ms on cout line 5 code reports
9 file:wrongLine.C line:8
10 */

where ^M denotes control-M.

Does this conform to standard? 2.95.x version's I've tried
"correctly" report 5.

Thanks in advance for your reply.

Gary

Since the code sample you posted has illegal characters in it, the C++
language does not specify the behavior.

 

[Raymond Martineau]

On g++ version 3.X I get the "wrong" line number, 8 reported
for the following code:

1 #include <iostream>
2 using namespace std;
3 int main(void)
4 {
5 ^M^M^Mcout << "file:" << __FILE__ << " line:" << __LINE__ << endl;
6 }
7 /*
8 3 ^Ms on cout line 5 code reports
9 file:wrongLine.C line:8
10 */

where ^M denotes control-M.

Does this conform to standard? 2.95.x version's I've tried
"correctly" report 5.

[semi-ot for CLC]
'^M' is one of the characters used to denote a newline. Two other
combinations can be '^J' and the '^M^J' pair.

The actual newline information used is system-dependant. In this case, it
looks like G++ is attempting to intellegently detect which newline is in
use (Dos/Unix compatability), causing the difference between Line numbers.
[/ot]