P-Code compatibility

P-Code incompatibility (within .42m files) may be introduced from version to version.

Recompilation is only needed when the p-code becomes incompatible. When executing a program with an older p-code version as expected, fglrun will raise the error -6201.

The product version number has the form X.YY.ZZ and identifies a given Genero BDL release.

If the new version is different from the older version by first three digits, recompile the program code sources and form files.

Recompile your .4gl sources, when upgrading to a new version with a different X.YY number. For example, you must recompile your sources when upgrading from 2.50 to 3.00, from 2.40 to 2.50, or from 2.51. to 2.52.

Recompilation is not required when upgrading to a version with a different ZZ number. For example, when upgrading from 2.00 to 2.01. However, there is potentially some p-code optimization benefits to be gained from doing so.

When upgrading, you may need to recreate the C-Extensions libraries: C extension libraries must be provided as dynamically loadable modules and a rebuild is generally not needed. However, if the C-Extension API header files have changed, you must recompile your C sources. Check $FGLDIR/include/f2c for C Extension API header file changes.