[[ [Scripted Compiler] :: '''Code generation''' ]]
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Nothing concrete here yet.

References

   * compilers & interpreters archive -- runtime code generation subject area [http://www.dcs.qmul.ac.uk/SEL-HPC/Articles/GeneratedHtml/comp.rcg.html]

   * compilers & interpreters archive -- general code generation techniques subject area [http://www.dcs.qmul.ac.uk/SEL-HPC/Articles/GeneratedHtml/comp.gen.html]

   * [Cameron Laird]'s Regular Expressions Column [http://regularexpressions.com] talked in April 2004 about 'Rapid Development of An Assembler Using Python' [http://www.unixreview.com/documents/s=2472/ur0404e/].  Also coded in [Python], and therefore scriptable in it, is Atul Varma's "Mini-[C] Compiler" [http://people.cs.uchicago.edu/~varmaa/mini_c/].

   * See [Playing Assembler] as well.

   * And [GPS]' [IA-32/x86 assembler in Tcl].

Keyword: BURS - Bottom Up Rewrite System - Related to LR parsing.

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'''Discussions'''

[AK]:
The runtime assembler/code-generator [Lightning] (written in C) is [GPL],
the concept however can be used to generate machine code from within [Tcl],
plus some bits to write [ELF], [COFF], etc. libraries the low-level
backend would be done.

[jcw]:
''Too much machinery - I'd generate raw into a bytearray.  Store it
that way too.  ELF is for linkers and other arcane concepts <wink>''

[AK]:
Do not forget pre-compiling of binaries. Even if the compiler is in an
extension I do not want to deliver it with every application. Especially
not wrapped applications..

[jcw]:
''Absolutely.  Which is why I said: "store it that way too".''

[AK]:
Hm, sort of like tbcload, but machine code ? ... A mixture of bytecode
and machine code might be of interest. A loader format containing binary data
in a script language wrapper ... Oh, I just remember [Oberon]'s ''[Slim Binaries]''.
These store a portable AST of the input (not bytecode) and use a simple
compiler/mapper to machine code when loading. Lower-level than Tcl bytecodes,
and are still as efficient as machine code, because in the end they are
machine-code. I think I will start a new thread below to collect and merge
the thoughts into something cohesive.

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Related software

   * Softwire @ http://softwire.sourceforge.net/ ([LGPL]).

   * See also [tcc], which can compile and run C in core, but also knows about ELF ([LGPL]).

   * Small Device C Compiler @ http://sdcc.sourceforge.net/ ([GPL]).

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A Tcl-coded assembler that processes input with this sort
of appearance
             ld   r3 0x44
             div  r1 r6
    label:  call subr_a
      ...
looks to be the fun sort of thing [RS] turns out in a weekend, '''and''' having Tcl computational capabilities at hand would make it actually useful.  Think how much nicer such an assembler would be just in its "macro" functionality.

[RS] replies: Sure enough -
part of it is since long at [Playing Assembler], but that executes the code directly instead of generating real machine code. Feel free to modify it! As I haven't done real assembler for 10 years now, it would involve a bit more work for me than usual for a fun project - and I remember from x86 ASM how easy one can crash the box :(


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[[ [Scripted Compiler] :: '''Code generation''' ]]