Auto-compilation of imported modules

Imported local and package modules are compiled automatically if needed.

When the imported module is located in the same directory as the compiled module or in a sub-directory following the package paths, fglcomp will automatically compile the imported module, if the .42m file does not exist, or is older than the corresponding .4gl source file.

The fglcomp compiler builds the .42m in the current directory, in the package path directory, or in in the output directory specified by --output-dir option.

The automatic recompilation of imported modules applies recursively: For example, when a main.4gl module imports module1 which in turn imports module2, and module2.4gl is more recent as module2.42m, fglcomp will automatically compile module2.4gl.

fglcomp uses FGLLDPATH content to search for the .42m modules used by IMPORT FGL. Modules located in other directories and found by FGLLDPATH should already be compiled.


Auto-compilation of imported modules is only supported if the imported module is in the current directory or in a package path. Regular modules located in other directories and found by FGLLDPATH must already be compiled.

When using packages, fglcomp can find modules in sub-directories by following the package-path specified in IMPORT FGL package-path.*. Therefore, FGLLDPATH should not be set during compilation with packages. FGLLDPATH can be set at runtime to find .42m modules from a top-dir that is different from the source top-dir.

To avoid implicit compilation of imported modules, use the --implicit=none option of fglcomp. If the .42m file exists but the .4gl source file cannot be found, fglcomp imports the .42m file as is.

The fglcomp --implicit=none option is provided for specific cases. Do not use this option when not really needed: Auto-compilation of imported modules is the recommended default.