Difference between revisions of "Compiler development articles"
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[[Coding style]] | [[Coding style]] | ||
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== Enable new style smartlinking (freebsd,linux) == | == Enable new style smartlinking (freebsd,linux) == |
Revision as of 11:09, 17 May 2007
The current FPC version under developement is 2.1.1. Compiler internals are documented at the evolving FPC internals page.
General
Enable new style smartlinking (freebsd,linux)
- 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.
C++ linking
See http://rvelthuis.bei.t-online.de/articles/articles-cppobjs.htm
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"
Processor dependent
See also platform list.
Passing Pascal Types to C Routines