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28 lines
1.2 KiB
28 lines
1.2 KiB
2 years ago
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Exercise 5.47: This section described how to
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modify the explicit-control evaluator so that interpreted code can call
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compiled procedures. Show how to modify the compiler so that compiled
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procedures can call not only primitive procedures and compiled procedures, but
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interpreted procedures as well. This requires modifying
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compile-procedure-call to handle the case of compound (interpreted)
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procedures. Be sure to handle all the same target and linkage
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combinations as in compile-proc-appl. To do the actual procedure
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application, the code needs to jump to the evaluator’s compound-apply
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entry point. This label cannot be directly referenced in object code (since
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the assembler requires that all labels referenced by the code it is assembling
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be defined there), so we will add a register called compapp to the
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evaluator machine to hold this entry point, and add an instruction to
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initialize it:
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(assign compapp (label compound-apply))
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;; branches if flag is set:
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(branch (label external-entry))
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read-eval-print-loop …
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To test your code, start by defining a procedure f that calls a
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procedure g. Use compile-and-go to compile the definition of
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f and start the evaluator. Now, typing at the evaluator, define
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g and try to call f.
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