(Corresponds to Section 2.3 of ANSI X3.9-1978 FORTRAN 77.)
Use of an exclamation point (`!') to begin a trailing comment (a comment that extends to the end of the same source line) is permitted under the following conditions:
Use of a semicolon (`;') as a statement separator is permitted under the following conditions:
IFstatement nor a non-construct
WHEREstatement (a Fortran 90 feature) may be followed (in the same, possibly continued, line) by a semicolon used as a statement separator.
This restriction avoids the confusion that can result when reading a line such as:
IF (VALIDP) CALL FOO; CALL BAR
Some readers might think the `CALL BAR' is executed
only if `VALIDP' is
.TRUE., while others might
assume its execution is unconditional.
(At present, g77 does not diagnose code that violates this restriction.)