P-Code compatibility across versions

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.

Recompile your .4gl sources when upgrading to a new features release. Recompilation is not required when upgrading to a bug-fix release.

Feature and bug-fix releases are distinguished by the product version number. The product version number can be found by executing the fglrun command with the -V option.

The product version number has the following format: M.FF.BB, where M stands for the major release number, FF is a feature number, and BB is the bug-fix number. For example: 2.31.14.
  • A new feature release is identified by the M.FF part of the product version number.
  • A bug-fix release is identified by the BB part of the product version 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.