50 lines
2.1 KiB
Text
50 lines
2.1 KiB
Text
.TL
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The ACK Pascal Compiler
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.AU
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Aad Geudeke
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Frans Hofmeester
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.AI
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Dept. of Mathematics and Computer Science
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Vrije Universiteit
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Amsterdam, The Netherlands
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.AB
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This document describes the implementation of a Pascal to EM compiler. The
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compiler is written in C. The lexical analysis is done using a hand-written
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lexical analyzer. Semantic analysis makes use of the extended LL(1) parser
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generator LLgen. Several EM utility modules are used in the compiler.
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.AE
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.sp 2
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.NH
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Introduction
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.PP
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.nh
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The Pascal front end of the Amsterdam Compiler Kit (ACK) complies with the
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requirements of the international standard published by the International
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Organization for Standardization (ISO) [ISO]. An informal description, which
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unfortunately is not conforming to the standard, of the programming language
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Pascal is given in [JEN].
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.PP
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The main reason for rewriting the Pascal compiler was that the old Pascal
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compiler was written in Pascal itself, and a disadvantage of it was its
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lack of flexibility. The compiler did not meet the needs of the current
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ACK-framework, which makes use of modern parsing techniques and utility
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modules. In this framework it is, for example, possible to use a fast back
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end. Such a back end translates directly to object code [ACK]. Our compiler is
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written in C and it is designed similar to the current C and Modula-2 compiler
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of ACK.
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.PP
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Chapter 2 describes the basic structure of the compiler. Chapter 3 discusses
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the code generation of the main Pascal constructs. Chapter 4 covers one of
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the major components of Pascal, viz. the conformant array. In Chapter 5 the
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various compiler options that can be used are enumerated. The extensions
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to the standard and the deviations from the standard are listed in Chapter
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6 and 7. Chapter 8 presents some ideas to improve the standard. Chapter 9
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gives a short overview of testing the compiler. The major differences
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between the old and new compiler can be found in Chapter 10. Suggestions
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to improve the compiler are described in Chapter 11. The appendices
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contain the grammar of Pascal and the changes made to the ACK Pascal run time
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library. A translation of a Pascal program to EM code as example is presented.
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.bp
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