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* doc/ref/api-evaluation.texi: Add documentation for the standard compilation interface, and some notes about compiled files. * doc/ref/api-procedures.texi (Compiled Procedures): A stub at documenting compiled procedures. * doc/ref/compiler.texi (Compiling to the Virtual Machine): Flesh out with some structure, though much of the text remains to be written. This stuff is hard to write!
132 lines
3.3 KiB
Text
132 lines
3.3 KiB
Text
@c -*-texinfo-*-
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@c This is part of the GNU Guile Reference Manual.
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@c Copyright (C) 2008
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@c Free Software Foundation, Inc.
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@c See the file guile.texi for copying conditions.
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@node Compiling to the Virtual Machine
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@section Compiling to the Virtual Machine
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Compilers have a mystique about them that is attractive and
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off-putting at the same time. They are attractive because they are
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magical -- they transform inert text into live results, like throwing
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the switch on Frankenstein. However, this magic is perceived by many
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to be impenetrable.
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This section aims to pull back the veil from over Guile's compiler
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implementation, some reference to the wizard of oz FIXME.
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REFFIXME, if you're lost and you just wanted to know how to compile
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your .scm file.
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@menu
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* Compiler Tower::
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* The Scheme Compiler::
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* GHIL::
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* GLIL::
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* Object Code::
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@end menu
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@node Compiler Tower
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@subsection Compiler Tower
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Guile's compiler is quite simple, actually -- its @emph{compilers}, to
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put it more accurately. Guile defines a tower of languages, starting
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at Scheme and progressively simplifying down to languages that
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resemble the VM instruction set (REFFIXME).
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Each language knows how to compile to the next, so each step is simple
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and understandable. Furthermore, this set of languages is not
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hardcoded into Guile, so it is possible for the user to add new
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high-level languages, new passes, or even different compilation
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targets.
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lookup-language
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(lang xxx spec)
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(system-base-language)
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describe:
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(define-record <language>
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name
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title
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version
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reader
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printer
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(parser #f)
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(read-file #f)
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(compilers '())
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(evaluator #f))
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(define-macro (define-language name . spec)
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(lookup-compilation-order from to)
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language definition
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compiling from here to there
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the normal tower: scheme, ghil, glil, object code
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maybe from there serialized to disk
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or if at repl, brought back to life by compiling to ``value''
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compile-file defaults to compiling to objcode
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compile defaults to compiling to value
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((lambda (x) ((compile x) x)) '(lambda (x) ((compile x) x)))
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quine
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@node The Scheme Compiler
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@subsection The Scheme Compiler
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macro expansion
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define-scheme-translator
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inlining
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format of the environment
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compile-time-environment
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symbols resolved as local, external, or toplevel
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@node GHIL
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@subsection GHIL
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ghil environments
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structured, typed intermediate language, close to scheme
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with an s-expression representation
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,lang ghil
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some pre-optimization
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real name of the game is closure elimination -- fixing letrec
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@node GLIL
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@subsection GLIL
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structured, typed intermediate language, close to object code
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passes through the env
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no let, no lambda, no closures, just labels and branches and constants
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and code. Well, there's a bit more, but that's the flavor of GLIL.
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Compiled code will effectively be a thunk, of no arguments, but
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optionally closing over some number of variables (which should be
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captured via `make-closure' REFFIXME.
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@node Object Code
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@subsection Object Code
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describe the env -- module + externals (the actual values!)
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The env is used when compiling to value -- effectively calling the
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thunk from objcode->program with a certain current module and with
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those externals. so you can recompile a closure at runtime, a trick
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that goops uses.
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