Qualifying imported symbols

The fglcomp compiler can automatically qualify imported symbols.

The fglcomp compiler provides the --qualify-imports option, to automatically add module prefixes to all imported symbols that are not yet qualified.

Important: The --qualify-imports option does not compile imported sources. The imported modules need to be available as .42m pcode modules.

By default, the modified source is written to the standard output stream (stdout). No output is produced, if no modification is required. To replace the orignal source file directly, add the --inplace option. With the --inplace option, fglcomp makes a copy of the original source, using the .4gl~ file extension.

Example with two modules defining public types, constants, variables and functions:

-- module1.4gl
PUBLIC CONSTANT const1 = 500
PUBLIC TYPE type1 INTEGER
PUBLIC FUNCTION func1( p1 type1 )
    DISPLAY "func1:", p1
END FUNCTION

-- module2.4gl
PUBLIC DEFINE var2 STRING
PUBLIC CONSTANT const2 = "abc"

Assuming the following importing module:

IMPORT FGL module1
IMPORT FGL module2
MAIN
    DEFINE v type1
    LET v = const1
    CALL func1( v )
    LET var2 = "abc"
    DISPLAY const2
END MAIN

The fglcomp --qualify-imports will produce this output from the above source file:

IMPORT FGL module1
IMPORT FGL module2
MAIN
    DEFINE v module1.type1
    LET v = module1.const1
    CALL module1.func1( v )
    LET module2.var2 = "abc"
    DISPLAY module2.const2
END MAIN

If two modules define the same symbol name, fglcomp --qualify-imports will produce the error -8401.

Before refactoring the sources with the --qualify-imports option, you can find unqualified imported symbols with the -W unqualified-imports warning:

$ fglcomp -W unqualified-imports main.4gl
main.4gl:4:14:4:18:warning:(-8452) Unqualified imported symbol. Expecting 'module1.type1'.
main.4gl:5:13:5:18:warning:(-8452) Unqualified imported symbol. Expecting 'module1.const1'.
main.4gl:6:10:6:14:warning:(-8452) Unqualified imported symbol. Expecting 'module1.func1'.
main.4gl:7:9:7:12:warning:(-8452) Unqualified imported symbol. Expecting 'module2.var2'.
main.4gl:8:13:8:18:warning:(-8452) Unqualified imported symbol. Expecting 'module2.const2'.