/* $NetBSD: plural.y,v 1.1.1.1 2016/01/10 21:36:18 christos Exp $ */ %{ /* Expression parsing for plural form selection. Copyright (C) 2000, 2001 Free Software Foundation, Inc. Written by Ulrich Drepper , 2000. This program is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2, 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* The bison generated parser uses alloca. AIX 3 forces us to put this declaration at the beginning of the file. The declaration in bison's skeleton file comes too late. This must come before because may include arbitrary system headers. */ #if defined _AIX && !defined __GNUC__ #pragma alloca #endif #ifdef HAVE_CONFIG_H # include #endif #include #include #include "plural-exp.h" /* The main function generated by the parser is called __gettextparse, but we want it to be called PLURAL_PARSE. */ #ifndef _LIBC # define __gettextparse PLURAL_PARSE #endif #define YYLEX_PARAM &((struct parse_args *) arg)->cp #define YYPARSE_PARAM arg %} %pure_parser %expect 7 %union { unsigned long int num; enum operator op; struct expression *exp; } %{ /* Prototypes for local functions. */ static struct expression *new_exp PARAMS ((int nargs, enum operator op, struct expression * const *args)); static inline struct expression *new_exp_0 PARAMS ((enum operator op)); static inline struct expression *new_exp_1 PARAMS ((enum operator op, struct expression *right)); static struct expression *new_exp_2 PARAMS ((enum operator op, struct expression *left, struct expression *right)); static inline struct expression *new_exp_3 PARAMS ((enum operator op, struct expression *bexp, struct expression *tbranch, struct expression *fbranch)); static int yylex PARAMS ((YYSTYPE *lval, const char **pexp)); static void yyerror PARAMS ((const char *str)); /* Allocation of expressions. */ static struct expression * new_exp (nargs, op, args) int nargs; enum operator op; struct expression * const *args; { int i; struct expression *newp; /* If any of the argument could not be malloc'ed, just return NULL. */ for (i = nargs - 1; i >= 0; i--) if (args[i] == NULL) goto fail; /* Allocate a new expression. */ newp = (struct expression *) malloc (sizeof (*newp)); if (newp != NULL) { newp->nargs = nargs; newp->operation = op; for (i = nargs - 1; i >= 0; i--) newp->val.args[i] = args[i]; return newp; } fail: for (i = nargs - 1; i >= 0; i--) FREE_EXPRESSION (args[i]); return NULL; } static inline struct expression * new_exp_0 (op) enum operator op; { return new_exp (0, op, NULL); } static inline struct expression * new_exp_1 (op, right) enum operator op; struct expression *right; { struct expression *args[1]; args[0] = right; return new_exp (1, op, args); } static struct expression * new_exp_2 (op, left, right) enum operator op; struct expression *left; struct expression *right; { struct expression *args[2]; args[0] = left; args[1] = right; return new_exp (2, op, args); } static inline struct expression * new_exp_3 (op, bexp, tbranch, fbranch) enum operator op; struct expression *bexp; struct expression *tbranch; struct expression *fbranch; { struct expression *args[3]; args[0] = bexp; args[1] = tbranch; args[2] = fbranch; return new_exp (3, op, args); } %} /* This declares that all operators have the same associativity and the precedence order as in C. See [Harbison, Steele: C, A Reference Manual]. There is no unary minus and no bitwise operators. Operators with the same syntactic behaviour have been merged into a single token, to save space in the array generated by bison. */ %right '?' /* ? */ %left '|' /* || */ %left '&' /* && */ %left EQUOP2 /* == != */ %left CMPOP2 /* < > <= >= */ %left ADDOP2 /* + - */ %left MULOP2 /* * / % */ %right '!' /* ! */ %token EQUOP2 CMPOP2 ADDOP2 MULOP2 %token NUMBER %type exp %% start: exp { if ($1 == NULL) YYABORT; ((struct parse_args *) arg)->res = $1; } ; exp: exp '?' exp ':' exp { $$ = new_exp_3 (qmop, $1, $3, $5); } | exp '|' exp { $$ = new_exp_2 (lor, $1, $3); } | exp '&' exp { $$ = new_exp_2 (land, $1, $3); } | exp EQUOP2 exp { $$ = new_exp_2 ($2, $1, $3); } | exp CMPOP2 exp { $$ = new_exp_2 ($2, $1, $3); } | exp ADDOP2 exp { $$ = new_exp_2 ($2, $1, $3); } | exp MULOP2 exp { $$ = new_exp_2 ($2, $1, $3); } | '!' exp { $$ = new_exp_1 (lnot, $2); } | 'n' { $$ = new_exp_0 (var); } | NUMBER { if (($$ = new_exp_0 (num)) != NULL) $$->val.num = $1; } | '(' exp ')' { $$ = $2; } ; %% void internal_function FREE_EXPRESSION (exp) struct expression *exp; { if (exp == NULL) return; /* Handle the recursive case. */ switch (exp->nargs) { case 3: FREE_EXPRESSION (exp->val.args[2]); /* FALLTHROUGH */ case 2: FREE_EXPRESSION (exp->val.args[1]); /* FALLTHROUGH */ case 1: FREE_EXPRESSION (exp->val.args[0]); /* FALLTHROUGH */ default: break; } free (exp); } static int yylex (lval, pexp) YYSTYPE *lval; const char **pexp; { const char *exp = *pexp; int result; while (1) { if (exp[0] == '\0') { *pexp = exp; return YYEOF; } if (exp[0] != ' ' && exp[0] != '\t') break; ++exp; } result = *exp++; switch (result) { case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': { unsigned long int n = result - '0'; while (exp[0] >= '0' && exp[0] <= '9') { n *= 10; n += exp[0] - '0'; ++exp; } lval->num = n; result = NUMBER; } break; case '=': if (exp[0] == '=') { ++exp; lval->op = equal; result = EQUOP2; } else result = YYERRCODE; break; case '!': if (exp[0] == '=') { ++exp; lval->op = not_equal; result = EQUOP2; } break; case '&': case '|': if (exp[0] == result) ++exp; else result = YYERRCODE; break; case '<': if (exp[0] == '=') { ++exp; lval->op = less_or_equal; } else lval->op = less_than; result = CMPOP2; break; case '>': if (exp[0] == '=') { ++exp; lval->op = greater_or_equal; } else lval->op = greater_than; result = CMPOP2; break; case '*': lval->op = mult; result = MULOP2; break; case '/': lval->op = divide; result = MULOP2; break; case '%': lval->op = module; result = MULOP2; break; case '+': lval->op = plus; result = ADDOP2; break; case '-': lval->op = minus; result = ADDOP2; break; case 'n': case '?': case ':': case '(': case ')': /* Nothing, just return the character. */ break; case ';': case '\n': case '\0': /* Be safe and let the user call this function again. */ --exp; result = YYEOF; break; default: result = YYERRCODE; #if YYDEBUG != 0 --exp; #endif break; } *pexp = exp; return result; } static void yyerror (str) const char *str; { /* Do nothing. We don't print error messages here. */ }