(g77.info.gz) Ugly Assigned Labels

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 Ugly Assigned Labels
 --------------------
 
    The `-fugly-assign' option forces `g77' to use the same storage for
 assigned labels as it would for a normal assignment to the same
 variable.
 
    For example, consider the following code fragment:
 
      I = 3
      ASSIGN 10 TO I
 
 Normally, for portability and improved diagnostics, `g77' reserves
 distinct storage for a "sibling" of `I', used only for `ASSIGN'
 statements to that variable (along with the corresponding
 assigned-`GOTO' and assigned-`FORMAT'-I/O statements that reference the
 variable).
 
    However, some code (that violates the ANSI FORTRAN 77 standard)
 attempts to copy assigned labels among variables involved with `ASSIGN'
 statements, as in:
 
      ASSIGN 10 TO I
      ISTATE(5) = I
      ...
      J = ISTATE(ICUR)
      GOTO J
 
 Such code doesn't work under `g77' unless `-fugly-assign' is specified
 on the command-line, ensuring that the value of `I' referenced in the
 second line is whatever value `g77' uses to designate statement label
 `10', so the value may be copied into the `ISTATE' array, later
 retrieved into a variable of the appropriate type (`J'), and used as
 the target of an assigned-`GOTO' statement.
 
       when `-fugly-assign' is
 specified, `g77' requires the type of variables specified in
 assigned-label contexts *must* be the same type returned by `%LOC()'.
 On many systems, this type is effectively the same as
 `INTEGER(KIND=1)', while, on others, it is effectively the same as
 `INTEGER(KIND=2)'.
 
    Do *not* depend on `g77' actually writing valid pointers to these
 variables, however.  While `g77' currently chooses that implementation,
 it might be changed in the future.
 
     Assigned Statement Labels (ASSIGN and GOTO) Assigned
 Statement Labels, for implementation details on assigned-statement
 labels.
 

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