Converting older fortran files to .f90 or .f95

[bcruey]

I have the source code for a program that was written in Fortran 77 (i.e. program.for). I get many compiler errors when I try to compile this file. I believe the problem is that many of the lines of code exceed the 72 columns allowed inFortran77. I want to convert this file to a .f90. Is there a simple command for visual studio or command line that I can use to convert this file or do I have to do it manually?

[IDZ_A_Intel · Accepted solution]

I have seen tools to do this, but they're not part of the Intel Visual Fortran product. You can specify a fixed form line length of 80 or 132 - that's probably a better bet. In Visual Studio, this is under Fortran > Language.

[nvaneck]

Here's what I made to do this for me a few years ago. Just run it and give the source file name to convert.

[bash]  CHARACTER*133 LINE(6000),FILE1*64,FILE2*64,C
      READ (*,'(A64)') FILE1
      OPEN(1,FILE=FILE1)
      L=LEN_TRIM(FILE1)
      FILE2=FILE1(:L-3)//"F90"
      OPEN (2,FILE=FILE2,STATUS='REPLACE')
      N=1
   10 READ (1,'(A132)',END=20) LINE(N)
      N=N+1
      GO TO 10
   20 DO I=N-1,1,-1
         L=LEN_TRIM(LINE(I))
         IF (L.EQ.0) CYCLE
         IF (LINE(I)(1:1).EQ.CHAR(9))  then
            LINE(I)(7:)=LINE(I)(2:)
            LINE(I)(1:6)=' '
         ELSEIF (LINE(I)(2:2).EQ.CHAR(9))  then
            LINE(I)(7:)=LINE(I)(3:)
            LINE(I)(2:6)=' '
         ELSEIF (LINE(I)(3:3).EQ.CHAR(9))  then
            LINE(I)(7:)=LINE(I)(4:)
            LINE(I)(3:6)=' '
         ELSEIF (LINE(I)(4:4).EQ.CHAR(9))  then
            LINE(I)(7:)=LINE(I)(5:)
            LINE(I)(4:6)=' '
         ELSEIF (LINE(I)(5:5).EQ.CHAR(9))  then
            LINE(I)(7:)=LINE(I)(6:)
            LINE(I)(5:6)=' '
         ELSEIF (LINE(I)(6:6).EQ.CHAR(9))  then
            LINE(I)(6:6)=' '
         ENDIF
        
         IF (LINE(I)(1:1) .EQ. 'C' .OR. LINE(I)(1:1).EQ. '*') THEN
            LINE(I)(1:1)='!'
         ELSEIF (LINE(I)(6:6) .EQ.CHAR(9)) THEN
            LINE(I)(6:6)=' '
         ELSEIF (LINE(I)(6:6) .NE.' ') THEN
            LINE(I)(6:6)='&'
            L=LEN_TRIM(LINE(I-1))
            LINE(I-1)(L+1:L+1)='&'
         ENDIF
      END DO
      WRITE(2,'("!DEC$ FREEFORM")')
      DO I=1,N-1
         K=1
         DO WHILE (K.GT.0)
            K=INDEX(LINE(I),CHAR(9))
            J=MOD(K,4)
            IF (K.GT.0) THEN
               LINE(I)(K+J+1:)=LINE(I)(K+1:)
               LINE(I)(K:K+J)=' '
            ENDIF
         END DO
         L=LEN_TRIM(LINE(I))
         IF (L .LE.132) THEN
            K=INDEX(LINE(I),'REAL*8')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'REAL(8)'//LINE(I)(K+6:L)
            K=INDEX(LINE(I),'REAL*4')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'REAL(4)'//LINE(I)(K+6:L)
            K=INDEX(LINE(I),'INTEGER*4')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'INTEGER(4)'//LINE(I)(K+9:L)
            K=INDEX(LINE(I),'INTEGER*2')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'INTEGER(2)'//LINE(I)(K+9:L)
            K=INDEX(LINE(I),'LOGICAL*4')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'LOGICAL(4)'//LINE(I)(K+9:L)
            K=INDEX(LINE(I),'LOGICAL*2')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'LOGICAL(2)'//LINE(I)(K+9:L)
            K=INDEX(LINE(I),'LOGICAL*1')
            IF (K.GT.0) LINE(I)(1:L+1)=LINE(I)(1:K-1)//'LOGICAL(1)'//LINE(I)(K+9:L)
            L=LEN_TRIM(LINE(I))
            K=INDEX(LINE(I),'SETCOM.FOR')
            IF (K.GT.0) LINE(I)(K:K+9)='SETCOM.F90'
            IF (INDEX(LINE(I),'AUTOMATIC')) CYCLE
            WRITE(2,'(A)') LINE(I)(1:L)
         ELSEIF(LINE(I)(133:133) .EQ. '&') THEN
            C=LINE(I)(132:132)
            LINE(I)(132:132)='&'
            LINE(I+1)(8:)=LINE(I+1)(7:)
            LINE(I+1)(7:7)=C
            WRITE(2,'(A)') LINE(I)(1:132)
         ENDIF
      END DO
      END[/bash]