dkochmanski / language.c

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Introduction

This library provides parsers for the C programming language and its preprocessor as described in Annex A of SO/IEC 9899:2017.

This library uses package-local nicknames. It has been tested in SBCL.

Tutorial

This section discusses different modules provided by the library:

*The Interface Package

This module provides a high-level interface consisting of convenience functions for parsing and evaluating CPP or C inputs or doing multiple of those things at once.

*The Preprocessor Language

This module provides a parser, a meta-model and an evaluator for the C preprocessor language.

*The C Language

This module provides a parser and a meta-model.

The Interface Package

The Preprocessor Language

Parsing

The ability to parse the C preprocessor language is provided by the language.c.cpp.parser systems.

After loading that system, a inputs such as strings and files can be parsed using the parse generic function:

(language.c.cpp.parser:parse "#define foo 1 + 2" 'list)

(:GROUP
 (:PART
  (((:DEFINE NIL :NAME (:IDENTIFIER NIL :NAME "foo" :BOUNDS (8 . 11))
     :REPLACEMENT
     ((:NUMBER NIL :VALUE "1" :BOUNDS (12 . 13))
      (:PUNCTUATOR NIL :WHICH :+ :BOUNDS (14 . 16))
      (:NUMBER NIL :VALUE "2" :BOUNDS (16 . 17)))
     :BOUNDS (1 . 17)))))
 :BOUNDS (0 . 17))
NIL
T

The second argument is a “builder” which controls the construction of the parse result (The “builder” concept, related protocols and their implementation can be found in the architecture.builder-protocol system). In the example above, the list builder has been used to produce a simple list-based representation of the parse tree.

Another possibility is producing a parse tree consisting of instances of classes defined in the language.c.cpp.model package:

(language.c.cpp.parser:parse "#define foo 1 + 2"
                             (make-instance 'language.c.cpp.model:builder))

#<LANGUAGE.C.CPP.MODEL:GROUP {10023739B3}>
NIL
T

Evaluating Syntax Trees

(let ((ast (language.c.cpp.parser:parse
            (format nil "#ifdef foo~@
                         #define foo 1~@
                         foo bar~@
                         baz fez~@
                         #endif~@
                         ")
            (make-instance 'language.c.cpp.model:builder)))
      ((environment (make-instance 'language.c.cpp.evaluator::environment))))
  (let ()
    (language.c.cpp.evaluator::evalute ast e *standard-output*)
    e))

The C language

Parsing

Evaluating

Dictionary