[Bug fortran/29671] New: preprocessor statements must start in column 1

[Bug fortran/29671] New: preprocessor statements must start in column 1

[franke dot daniel at gmail dot com]

Preprocessor statements (as if|else|endif|error|warning) must start in colum 1,
otherwise gfortran tries to handle them itself?!

$> cat pp.F90
PROGRAM test_preprocessor
 #error "EEE"         ! whitespace is significant
END PROGRAM

$> gfortran-4.3 -g -Wall pp.F90
 In file pp.F90:3

 #error "EEE"
1
Error: Unclassifiable statement at (1)


$> cat pp.F90
PROGRAM test_preprocessor
#error "EEE"
END PROGRAM

$> gfortran-4.3 -g -Wall pp.F90
pp.F90:3: error: #error "EEE"


Filed this as fortran report since gcc bails out as expected and both run
(afaik) the same preprocessor:

$> cat pp.c
int main() {
  #error "EEE"     /* whitespaces are not significant */
  return 0;
}

$> gcc-svn -g -Wall pp.c
pp.c:2:4: error: #error "EEE"


$> gfortran -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../../svn/gcc/configure
--prefix=/home/daniel/nfs/packages/i686-pc-linux-gnu/gcc-svn --disable-nls
--enable-threads=posix --enable-shared --enable-bootstrap --with-system-zlib
--program-suffix=-svn --enable-languages=c,c++,fortran
Thread model: posix
gcc version 4.3.0 20061030 (experimental)


-- 
           Summary: preprocessor statements must start in column 1
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: franke dot daniel at gmail dot com
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29671

[Bug fortran/29671] preprocessor statements must start in column 1

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2006-10-31 12:48 -------
The problem is that gfortran calls "cpp" with the -traditional-cpp option.

This causes some more modern constructs not to work and it also is the reason
behind your problem. (cf. PR 28662).

We need to use -traditional-cpp since "some tokens in C are not
tokens in Fortran so you could get the wrong result." (A.P. in the other PR)

The solution is to modify cpp to know fortran tokens (when called with
-lang-fortran).

Note this problem is not limited to gfortran; e.g. the NAG f95 compiler uses
Sun's public-domain fpp (netlib.org/fortran/), which has similar problems.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29671

[Bug fortran/29671] preprocessor statements must start in column 1

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2006-10-31 13:02 -------
Confirm and mark as enhancement.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-10-31 13:02:35
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29671