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/* Copyright (C) 2019 C. McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
%{
#include <ctype.h>
#include <err.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
int vasprintf(char **ret, const char *format, va_list ap);
static void yyerror(const char *str) {
errx(EX_DATAERR, "%s", str);
}
#define YYSTYPE char *
static char *fmt(const char *format, ...) {
char *str = NULL;
va_list ap;
va_start(ap, format);
vasprintf(&str, format, ap);
va_end(ap);
if (!str) err(EX_OSERR, "vasprintf");
return str;
}
static int yylex(void);
%}
%left ','
%right '=' MulAss DivAss ModAss AddAss SubAss ShlAss ShrAss AndAss XorAss OrAss
%right '?' ':'
%left Or
%left And
%left '|'
%left '^'
%left '&'
%left Eq Ne
%left '<' Le '>' Ge
%left Shl Shr
%left '+' '-'
%left '*' '/' '%'
%right '!' '~' Inc Dec Sizeof
%left '(' ')' '[' ']' Arr '.'
%token Var
%%
start:
expr { printf("%s\n", $1); }
;
expr:
Var
| '(' expr ')' { $$ = $2; }
| expr '[' expr ']' { $$ = fmt("(%s[%s])", $1, $3); }
| expr Arr Var { $$ = fmt("(%s->%s)", $1, $3); }
| expr '.' Var { $$ = fmt("(%s.%s)", $1, $3); }
| '!' expr { $$ = fmt("(!%s)", $2); }
| '~' expr { $$ = fmt("(~%s)", $2); }
| Inc expr { $$ = fmt("(++%s)", $2); }
| Dec expr { $$ = fmt("(--%s)", $2); }
| expr Inc { $$ = fmt("(%s++)", $1); }
| expr Dec { $$ = fmt("(%s--)", $1); }
| '-' expr %prec '!' { $$ = fmt("(-%s)", $2); }
| '*' expr %prec '!' { $$ = fmt("(*%s)", $2); }
| '&' expr %prec '!' { $$ = fmt("(&%s)", $2); }
| Sizeof expr { $$ = fmt("(sizeof %s)", $2); }
| expr '*' expr { $$ = fmt("(%s * %s)", $1, $3); }
| expr '/' expr { $$ = fmt("(%s / %s)", $1, $3); }
| expr '%' expr { $$ = fmt("(%s %% %s)", $1, $3); }
| expr '+' expr { $$ = fmt("(%s + %s)", $1, $3); }
| expr '-' expr { $$ = fmt("(%s - %s)", $1, $3); }
| expr Shl expr { $$ = fmt("(%s << %s)", $1, $3); }
| expr Shr expr { $$ = fmt("(%s >> %s)", $1, $3); }
| expr '<' expr { $$ = fmt("(%s < %s)", $1, $3); }
| expr Le expr { $$ = fmt("(%s <= %s)", $1, $3); }
| expr '>' expr { $$ = fmt("(%s > %s)", $1, $3); }
| expr Ge expr { $$ = fmt("(%s >= %s)", $1, $3); }
| expr Eq expr { $$ = fmt("(%s == %s)", $1, $3); }
| expr Ne expr { $$ = fmt("(%s != %s)", $1, $3); }
| expr '&' expr { $$ = fmt("(%s & %s)", $1, $3); }
| expr '^' expr { $$ = fmt("(%s ^ %s)", $1, $3); }
| expr '|' expr { $$ = fmt("(%s | %s)", $1, $3); }
| expr And expr { $$ = fmt("(%s && %s)", $1, $3); }
| expr Or expr { $$ = fmt("(%s || %s)", $1, $3); }
| expr '?' expr ':' expr { $$ = fmt("(%s ? %s : %s)", $1, $3, $5); }
| expr ass expr %prec '=' { $$ = fmt("(%s %s %s)", $1, $2, $3); }
| expr ',' expr { $$ = fmt("(%s, %s)", $1, $3); }
;
ass:
'=' { $$ = "="; }
| MulAss { $$ = "*="; }
| DivAss { $$ = "/="; }
| ModAss { $$ = "%="; }
| AddAss { $$ = "+="; }
| SubAss { $$ = "-="; }
| ShlAss { $$ = "<<="; }
| ShrAss { $$ = ">>="; }
| AndAss { $$ = "&="; }
| XorAss { $$ = "^="; }
| OrAss { $$ = "|="; }
;
%%
#define T(a, b) ((int)(a) << 8 | (int)(b))
static const char *input;
static int yylex(void) {
while (isspace(input[0])) input++;
if (!input[0]) return EOF;
int len;
for (len = 0; isalnum(input[len]) || input[len] == '_'; ++len);
if (len) {
if (!strncmp(input, "sizeof", len)) {
input += len;
return Sizeof;
}
yylval = fmt("%.*s", len, input);
input += len;
return Var;
}
int tok;
switch (T(input[0], input[1])) {
break; case T('-', '>'): tok = Arr;
break; case T('+', '+'): tok = Inc;
break; case T('-', '-'): tok = Dec;
break; case T('<', '<'): tok = Shl;
break; case T('>', '>'): tok = Shr;
break; case T('<', '='): tok = Le;
break; case T('>', '='): tok = Ge;
break; case T('=', '='): tok = Eq;
break; case T('!', '='): tok = Ne;
break; case T('&', '&'): tok = And;
break; case T('|', '|'): tok = Or;
break; case T('*', '='): tok = MulAss;
break; case T('/', '='): tok = DivAss;
break; case T('%', '='): tok = ModAss;
break; case T('+', '='): tok = AddAss;
break; case T('-', '='): tok = SubAss;
break; case T('&', '='): tok = AndAss;
break; case T('^', '='): tok = XorAss;
break; case T('|', '='): tok = OrAss;
break; default: return *input++;
}
input += 2;
switch (T(tok, input[0])) {
case T(Shl, '='): input++; return ShlAss;
case T(Shr, '='): input++; return ShrAss;
}
return tok;
}
int main(int argc, char *argv[]) {
for (int i = 1; i < argc; ++i) {
input = argv[i];
yyparse();
}
}
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