------- Comment #3 from burnus at gcc dot gnu dot org 2010-03-01 15:37 ------- I now check the standard.
a) Hollerith constants (not H... in FORMAT) are deleted in Fortran 77, but they were allowed in Fortran 66. F77 "A.2 Conflicts with ANSI X3.9-1966" has: "Hollerith constants and Hollerith data are not permitted in this standard. ANSI X3.9-1966 permitted the use of Hollerith constants in DATA and CALL statements" b) They seemingly need to be space padded; F77 "C.4 Hollerith Constant" has: "For an entity of type integer, real, or logical, the number of characters n in the corresponding Hollerith constant must be less than or equal to g, where g is the maximum number of characters that can be stored in a single numeric storage unit at one time. If n is less than g, the entity is initially defined with the n Hollerith characters extended on the right with g - n blank characters. Note that each Hollerith constant initially defines exactly one variable or array element. Also note that g is processor dependent" gfortran seemingly supports the common extension of allowing arrays (and not just array elements) to be initialized by a single constant. F66 has Holleriths in 4.2.6, 5.1.1.6 and some other places, though I could not spot the padding part. (I have not tried very hard.) c) The Hollerith constants should not be mixed up with the H edit descriptor, which has only be deleted in Fortran 95 (cf. "B.1.5 H edit descriptor" in F95). * * * > You folks think of the crazy stuff :) I will check into this. Well, that's the nice thing. With minimal modifications even Fortran IV programs will run with today's compiler. Compare this with Python where you need to modify/audit your code to go from Python 2 (released 2000) to 3 (released 2008). If you look at the example on page 46 of "Fortran - Programmer's Reference Manual" from 1956, you have no trouble except for the FREQUENCY statement (estimate of likelihood that a certain branch is taken) - and also on p. 48 it does not look to strange, though WRITE TAPE, END FILE and MORE PROGRAM do not exist anymore. And contrary to the the H edit descriptor, Hollerith constants wee not available; as there were no DATA nor subroutines that it not surprising. (There were functions but they could not be written in Fortran.) * * * See: http://gcc.gnu.org/wiki/GFortranStandards for the Fortran 77 and 66 standards - and the Fortran handbook of 1956. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43217
