mes/module/nyacc/lang/c99/cpp.scm
2017-02-18 17:06:50 -08:00

451 lines
16 KiB
Scheme

;;; lang/c/cpp.scm
;;;
;;; Copyright (C) 2015-2017 Matthew R. Wette
;;;
;;; This program is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation, either version 3 of the License, or
;;; (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;; C preprocessor. This is not complete.
(define-module (nyacc lang c99 cpp)
#:export (parse-cpp-stmt
cpp-line->stmt
parse-cpp-expr
eval-cpp-expr
cpp-expand-text
expand-cpp-macro-ref
)
#:use-module (nyacc parse)
#:use-module (nyacc lex)
#:use-module (nyacc lang util)
#:use-module (rnrs arithmetic bitwise)
#:use-module (ice-9 match)
)
(cond-expand
(guile-2)
(guile
(use-modules (ice-9 syncase)))
(mes))
(define c99-std-defs
'("__DATE__" "__FILE__" "__LINE__" "__STDC__" "__STDC_HOSTED__"
"__STDC_VERSION__" "__TIME__"))
(define (c99-std-def? str)
(let iter ((defs c99-std-defs))
(cond
((null? defs) #f)
((string=? (car defs) str) #t)
(else (iter (cdr defs))))))
(define (c99-std-val str)
(cond
((string=? str "__DATE__") "M01 01 2001")
((string=? str "__FILE__") "(unknown)")
((string=? str "__LINE__") 0)
((string=? str "__STDC__") 1)
((string=? str "__STDC_HOSTED__") 0)
((string=? "__STDC_VERSION__") 201701)
((string=? "__TIME__") "00:00:00")
(else #f)))
;; @deffn read-ellipsis ch
;; read ellipsis
(define (read-ellipsis ch)
(cond
((eof-object? ch) #f)
((char=? ch #\.) (read-char) (read-char) "...") ; assumes correct syntax
(else #f)))
;; @deffn cpp-define => (define (name "ADD") (args "X" "Y") (repl "X+Y"))
;; output is like
;; @code{(name "ABC") (repl "123")} or
;; @code{(name "ABC") (args "X" "Y") (repl "X+Y")}
(define (cpp-define)
(define (p-args la) ;; parse args
(if (eq? la #\()
(let iter ((args '()) (la (skip-il-ws (read-char))))
(cond
((eq? la #\)) (reverse args))
((read-c-ident la) =>
(lambda (arg) (iter (cons arg args) (skip-il-ws (read-char)))))
((read-ellipsis la) =>
(lambda (arg) (iter (cons arg args) (skip-il-ws (read-char)))))
((eq? la #\,) (iter args (skip-il-ws (read-char))))))
(begin (if (char? la) (unread-char la)) #f)))
(define (p-rest la) ;; parse rest
(cond ((eof-object? la) "")
(else (unread-char la) (drain-input (current-input-port)))))
(let* ((name (read-c-ident (skip-il-ws (read-char))))
(args (or (p-args (read-char)) '()))
(repl (p-rest (skip-il-ws (read-char)))))
(if (pair? args)
`(define (name ,name) (args . ,args) (repl ,repl))
`(define (name ,name) (repl ,repl)))))
;; @deffn cpp-include
;; Parse CPP include statement.
(define (cpp-include)
(let* ((beg-ch (skip-il-ws (read-char)))
(end-ch (if (eq? beg-ch #\<) #\> #\"))
(path (let iter ((cl (list beg-ch)) (ch (read-char)))
(if (eq? ch end-ch) (list->string (reverse (cons ch cl)))
(iter (cons ch cl) (read-char))))))
`(include ,path)))
;; @deffn cpp-line->stmt line defs => (stmt-type text)
;; Parse a line from a CPP statement and return a parse tree.
;; @example
;; (parse-cpp-stmt "define X 123") => (define "X" "123")
;; (parse-cpp-stmt "if defined(A) && defined(B) && defined(C)"
;; => (if "defined(A) && defined(B) && defined(C)")
;; @end example
;; To evaluate the @code{if} statements use @code{parse-cpp-expr} and
;; @code{eval-cpp-expr}.
(define (cpp-line->stmt line)
(define (rd-ident) (read-c-ident (skip-il-ws (read-char))))
(define (rd-num) (and=> (read-c-num (skip-il-ws (read-char))) cdr))
(define (rd-rest) (let ((ch (skip-il-ws (read-char))))
(if (not (eof-object? ch)) (unread-char ch))
(drain-input (current-input-port))))
(with-input-from-string line
(lambda ()
(let ((cmd (string->symbol (read-c-ident (skip-il-ws (read-char))))))
(case cmd
((include) (cpp-include))
((define) (cpp-define))
((undef) `(undef ,(rd-ident)))
((ifdef)
`(if ,(string-append "defined(" (rd-ident) ")" (rd-rest))))
((ifndef)
`(if ,(string-append "!defined(" (rd-ident) ")" (rd-rest))))
((if elif else endif line error pragma) (list cmd (rd-rest)))
(else '(unknown "")))))))
(include-from-path "nyacc/lang/c99/mach.d/cpptab.scm")
(include-from-path "nyacc/lang/c99/mach.d/cppact.scm")
(define raw-parser
(make-lalr-parser
(list (cons 'len-v len-v) (cons 'pat-v pat-v) (cons 'rto-v rto-v)
(cons 'mtab mtab) (cons 'act-v act-v))))
(define (cpp-err fmt . args)
(apply throw 'cpp-error fmt args))
;;.@deffn skip-il-ws ch
;; Skip in-line whitespace
(define skip-il-ws
(let ((il-ws (list->char-set '(#\space #\tab))))
(lambda (ch)
(cond
((eof-object? ch) ch)
((char-set-contains? il-ws ch) (skip-il-ws (read-char)))
(else ch)))))
;; Since we want to be able to get CPP statements with comment in tact
;; (e.g., for passing to @code{pretty-print-c99}) we need to remove
;; comments when parsing CPP expressions. We convert a comm-reader
;; into a comm-skipper here. And from that generate a lexer generator.
(define cpp-comm-skipper
(let ((reader (make-comm-reader '(("/*" . "*/")))))
(lambda (ch)
(reader ch #f))))
;; generate a lexical analyzer per string
(define gen-cpp-lexer
(make-lexer-generator mtab #:comm-skipper cpp-comm-skipper))
;; @deffn parse-cpp-expr text => tree
;; Given a string returns a cpp parse tree. This is called by
;; @code{eval-cpp-expr}. The text will have had all CPP defined symbols
;; expanded already so no identifiers should appear in the text.
;; A @code{cpp-error} will be thrown if a parse error occurs.
(define (parse-cpp-expr text)
(with-throw-handler
'nyacc-error
(lambda ()
(with-input-from-string text
(lambda () (raw-parser (gen-cpp-lexer)))))
(lambda (key fmt . args)
(apply throw 'cpp-error fmt args))))
;; @deffn eval-cpp-expr tree dict => datum
;; Evaluate a tree produced from @code{parse-cpp-expr}.
;; The tree passed to this routine is
(define (eval-cpp-expr tree dict)
(letrec
((tx (lambda (tr ix) (list-ref tr ix)))
(tx1 (lambda (tr) (tx tr 1)))
(ev (lambda (ex ix) (eval-expr (list-ref ex ix))))
(ev1 (lambda (ex) (ev ex 1))) ; eval expr in arg 1
(ev2 (lambda (ex) (ev ex 2))) ; eval expr in arg 2
(ev3 (lambda (ex) (ev ex 3))) ; eval expr in arg 3
(eval-expr
(lambda (tree)
(case (car tree)
((fixed) (string->number (tx1 tree)))
((char) (char->integer (tx1 tree)))
((defined) (if (assoc-ref dict (tx1 tree)) 1 0))
((pre-inc post-inc) (1+ (ev1 tree)))
((pre-dec post-dec) (1- (ev1 tree)))
((pos) (ev1 tree))
((neg) (- (ev1 tree)))
((bw-not) (bitwise-not (ev1 tree)))
((not) (if (zero? (ev1 tree)) 1 0))
((mul) (* (ev1 tree) (ev2 tree)))
((div) (/ (ev1 tree) (ev2 tree)))
((mod) (modulo (ev1 tree) (ev2 tree)))
((add) (+ (ev1 tree) (ev2 tree)))
((sub) (- (ev1 tree) (ev2 tree)))
((lshift) (bitwise-arithmetic-shift-left (ev1 tree) (ev2 tree)))
((rshift) (bitwise-arithmetic-shift-right (ev1 tree) (ev2 tree)))
((lt) (if (< (ev1 tree) (ev2 tree)) 1 0))
((le) (if (<= (ev1 tree) (ev2 tree)) 1 0))
((gt) (if (> (ev1 tree) (ev2 tree)) 1 0))
((ge) (if (>= (ev1 tree) (ev2 tree)) 1 0))
((equal) (if (= (ev1 tree) (ev2 tree)) 1 0))
((noteq) (if (= (ev1 tree) (ev2 tree)) 0 1))
((bw-or) (bitwise-ior (ev1 tree) (ev2 tree)))
((bw-xor) (bitwise-xor (ev1 tree) (ev2 tree)))
((bw-and) (bitwise-and (ev1 tree) (ev2 tree)))
((or) (if (and (zero? (ev1 tree)) (zero? (ev2 tree))) 0 1))
((and) (if (or (zero? (ev1 tree)) (zero? (ev2 tree))) 0 1))
((cond-expr) (if (zero? (ev1 tree)) (ev3 tree) (ev2 tree)))
((ident) (cpp-err "undefined identifier: ~S" (cadr tree)))
(else (error "incomplete implementation"))))))
(eval-expr tree)))
;; Note: scan-cpp-input scans replacement text. When identifiers are found
;; they are tested for expansion as follows:
;; @enumerate
;; @item If already expanded, then ignore.
;; @item If followed by @code{(}, then use @code{collect-args} to get the
;; arguments and ...
;; @item Otherwise insert the replacement text and continue scanning (at
;; first character of new replacement text.
;; @end enumerate
;; @deffn rtokl->string tokl => string
;; Convert reverse token-list to string.
(define (rtokl->string tokl)
;; Turn reverse chl into a string and insert it into the string list stl.
(define (add-chl chl stl)
(if (null? chl) stl (cons (list->string chl) stl)))
;; Works like this: Scan through the list of tokens (key-val pairs or lone
;; characters). Lone characters are collected in a list (@code{chl}); pairs
;; are converted into strings and combined with list of characters into a
;; list of strings. When done the list of strings is combined to one string.
(let iter ((stl '()) (chl '()) (nxt #f) (tkl tokl))
(cond
(nxt (iter (cons nxt (add-chl chl stl)) '() #f tkl))
((null? tkl) (apply string-append (add-chl chl stl)))
((char? (car tkl)) (iter stl (cons (car tkl) chl) nxt (cdr tkl)))
(else
(match tkl
((('arg . arg) 'dhash (key . val) . rest)
(iter stl chl nxt
(acons key (string-append val arg) (list-tail tkl 3))))
(((key . val) 'dhash ('arg . arg) . rest)
(iter stl chl nxt
(acons 'arg (string-append arg val) (list-tail tkl 3))))
((('arg . arg) 'hash . rest)
(iter stl chl (string-append "\"" arg "\"") (list-tail tkl 2)))
((('comm . val) . rest)
(iter stl chl (string-append "/*" val " */") (cdr tkl)))
((('ident . rval) ('ident . lval) . rest)
(iter stl chl (string-append " " rval) (cdr tkl)))
(((key . val) . rest)
(iter stl chl val rest))
(('space . rest)
(iter stl (cons #\space chl) nxt rest))
(otherwise
(error "no match" tkl)))))))
;; @deffn scan-cpp-input argd used dict end-tok => string
;; Process replacement text from the input port and generate a (reversed)
;; token-list. If end-tok, stop at, and push back, @code{,} or @code{)}.
;; If end-tok is @code{,} then read until @code{,} or @code{(}.
;; The argument @var{argd} is a dictionary (argument name, argument
;; value) pairs which will be expanded as needed. This routine is called
;; by collect-args, expand-cpp-repl and cpp-expand-text.
(define (scan-cpp-input argd dict used end-tok)
;; Works like this: scan for tokens (comments, parens, strings, char's, etc).
;; Tokens are collected in a (reverse ordered) list (tkl) and merged together
;; to a string on return using @code{rtokl->string}.
;; We just scanned "defined", now need to scan the arg to inhibit expansion.
;; For example, we have scanned "defined"; we now scan "(FOO)" or "FOO", and
;; return "defined(FOO)". We use ec (end-char) as terminal char:
;; #\) if starts with #( or #\nul if other.
(define (scan-defined-arg)
(let* ((ch (skip-il-ws (read-char)))
(ec (if (char=? ch #\() #\) #\null)))
(let iter ((chl '(#\())
(ec ec)
(ch (if (char=? ec #\)) (skip-il-ws (read-char)) ch)))
(cond
((eof-object? ch)
(if (char=? ec #\null)
(string-append "defined" (list->string (reverse (cons #\) chl))))
(cpp-err "illegal argument to `defined'")))
((char-set-contains? c:ir ch)
(iter (cons ch chl) ec (read-char)))
((char=? ec #\))
(if (char=? #\) (skip-il-ws ch))
(string-append "defined" (list->string (reverse (cons #\) chl))))
(cpp-err "garbage in argument to `defined'")))
((char=? ec #\null) ;; past identifier
(string-append "defined" (list->string (reverse (cons #\) chl)))))
(else
(cpp-err "illegal argument to `defined'"))))))
;; token list is list of
;; 1) characters as char
;; 2) identifiers as string
;; 3) strings as '(string . <string>)
;; 4) 'hash 'dhash
(let iter ((tkl '()) ; token list of
(lvl 0) ; level
(ch (read-char))) ; next character
(cond
;; have item to add, but first add in char's
;;(nxt (iter (cons nxt (add-chl chl tkl)) '() #f lvl ch))
;; If end of string or see end-ch at level 0, then return.
((eof-object? ch) (rtokl->string tkl))
((and (eqv? end-tok ch) (zero? lvl))
(unread-char ch) (rtokl->string tkl))
((and end-tok (char=? #\) ch) (zero? lvl))
(unread-char ch) (rtokl->string tkl))
((read-c-comm ch #f) =>
(lambda (cp) (iter (acons `comm (cdr cp) tkl) lvl (read-char))))
((char-set-contains? c:ws ch)
(if (and (pair? tkl) (char? (car tkl)))
(iter (cons 'space tkl) lvl (read-char))
(iter tkl lvl (read-char))))
((char=? #\( ch) (iter (cons ch tkl) (1+ lvl) (read-char)))
((char=? #\) ch) (iter (cons ch tkl) (1- lvl) (read-char)))
((char=? #\# ch)
(let ((ch (read-char)))
(if (eqv? ch #\#)
(iter (cons 'dhash tkl) lvl (read-char))
(iter (cons 'hash tkl) lvl ch))))
((read-c-string ch) =>
(lambda (st) (iter (acons 'string (cdr st) tkl) lvl (read-char))))
((read-c-ident ch) =>
(lambda (iden)
(if (equal? iden "defined")
;; "defined" is a special case
(let ((arg (scan-defined-arg)))
(iter (acons 'defined arg tkl) lvl (read-char)))
;; otherwise ...
(let* ((aval (assoc-ref argd iden)) ; lookup argument
(rval (assoc-ref dict iden))) ; lookup macro def
(cond
((member iden used) ; name used
(iter (cons iden tkl) lvl (read-char)))
(aval ; arg ref
(iter (acons 'arg aval tkl) lvl (read-char)))
((string? rval) ; cpp repl
(iter (acons 'string rval tkl) lvl (read-char)))
((pair? rval) ; cpp macro
(let* ((argl (car rval)) (text (cdr rval))
(argd (collect-args argl argd dict used))
(newl (expand-cpp-repl text argd dict (cons iden used))))
(iter (acons 'string newl tkl) lvl (read-char))))
(else ; normal identifier
(iter (acons 'ident iden tkl) lvl (read-char))))))))
(else
(iter (cons ch tkl) lvl (read-char))))))
;; @deffn collect-args argl argd dict used => argd
;; to be documented
;; I think argd is a passthrough for scan-cpp-input
;; argl: list of formal arguments in #define
;; argd: used? (maybe just a pass-through for scan-cpp-input
;; dict: dict of macro defs
;; used: list of already expanded macros
;; TODO clean this up
;; should be looking at #\( and eat up to matching #\)
(define (collect-args argl argd dict used)
(let iter ((argl argl) (argv '()) (ch (skip-il-ws (read-char))))
;; ch should always be #\(, #\, or #\)
(cond
((eqv? ch #\)) (reverse argv))
((null? argl) (cpp-err "arg count"))
((and (null? (cdr argl)) (string=? (car argl) "..."))
(let ((val (scan-cpp-input argd dict used #\))))
(iter (cdr argl) (acons "__VA_ARGS__" val argv) (read-char))))
((or (eqv? ch #\() (eqv? ch #\,))
(let ((val (scan-cpp-input argd dict used #\,)))
(iter (cdr argl) (acons (car argl) val argv) (read-char))))
(else (error "coding error, ch=" ch)))))
;; @deffn expand-cpp-repl
;; to be documented
(define (expand-cpp-repl repl argd dict used)
(with-input-from-string repl
(lambda () (scan-cpp-input argd dict used #f))))
;; @deffn cpp-expand-text text dict => string
(define (cpp-expand-text text dict)
(with-input-from-string text
(lambda () (scan-cpp-input '() dict '() #f))))
;; @deffn expand-cpp-macro-ref ident dict => repl|#f
;; Given an identifier seen in C99 input, this checks for associated
;; definition in @var{dict} (generated from CPP defines). If found,
;; the expansion is returned as a string. If @var{ident} refers
;; to a macro with arguments, then the arguments will be read from the
;; current input. The format of the @code{dict} entries are
;; @example
;; ("ABC" . "123")
;; ("MAX" ("X" "Y") . "((X)>(Y)?(X):(Y))")
;; @end example
(define (expand-cpp-macro-ref ident dict . rest)
(let ((used (if (pair? rest) (car rest) '()))
(rval (assoc-ref dict ident)))
(cond
((not rval) #f)
((member ident used) ident)
((string? rval)
(let ((expd (expand-cpp-repl rval '() dict (cons ident used))))
expd))
((pair? rval)
(let* ((argl (car rval)) (repl (cdr rval))
(argd (collect-args argl '() dict '()))
(expd (expand-cpp-repl repl argd dict (cons ident used))))
expd))
((c99-std-val ident))
(else #f))))
;;; --- last line ---