%{ /* Expression parsing for plural form selection. Copyright (C) 2000, 2001 Free Software Foundation, Inc. Written by Ulrich Drepper <drepper@cygnus.com>, 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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 <config.h> because <config.h> may include arbitrary system headers. */ #if defined _AIX && !defined __GNUC__ #pragma alloca #endif #ifdef HAVE_CONFIG_H # include <config.h> #endif #include <stddef.h> #include <stdlib.h> #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 <op> EQUOP2 CMPOP2 ADDOP2 MULOP2 %token <num> NUMBER %type <exp> 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. */ }