Compiler development articles
English (en) │
Bahasa Indonesia (id) │
The current FPC version under developement is 2.5.1. Compiler internals are documented at the evolving FPC internals page.
- in i_*.pas add tf_smartlink_sections to the flags field of the platform description record for your OS/CPU combo (in my case i_bsd.pas, the system_i386_freebsd_info record)
- in ogelf.pas scroll down to nearly the bottom, and add af_smartlink_sections to the flags field of as_i386_elf32_info
- run "(g)make all OPT='-Aas -k--gc-sections' at the toplevel to build using new smartlinking routines.
Note that FPC doesn't have negative VMT offsets due to GNU LD limitations.
The fundament of above C++ <-> OPas lies in COM interfaces: (quote from Rudy Velthuis)
"Well, all compilers must be able to create COM interfaces. Since in C++, these are simply pure abstract classes, and Delphi must have the same layout, for many reasons, they are all compatible. In fact, a pure abstract class pointer points to a structure of which the first entry is a VMT. This is also how interfaces are built"
See also platform list.