1 %{ 2 /* 3 * Copyright (C) 2009 The Android Open Source Project 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 #include <stdio.h> 19 #include <stdlib.h> 20 #include <string.h> 21 22 #include "expr.h" 23 #include "yydefs.h" 24 #include "parser.h" 25 26 extern int gLine; 27 extern int gColumn; 28 29 void yyerror(Expr** root, int* error_count, const char* s); 30 int yyparse(Expr** root, int* error_count); 31 32 struct yy_buffer_state; 33 void yy_switch_to_buffer(struct yy_buffer_state* new_buffer); 34 struct yy_buffer_state* yy_scan_string(const char* yystr); 35 36 %} 37 38 %locations 39 40 %union { 41 char* str; 42 Expr* expr; 43 struct { 44 int argc; 45 Expr** argv; 46 } args; 47 } 48 49 %token AND OR SUBSTR SUPERSTR EQ NE IF THEN ELSE ENDIF 50 %token <str> STRING BAD 51 %type <expr> expr 52 %type <args> arglist 53 54 %parse-param {Expr** root} 55 %parse-param {int* error_count} 56 %error-verbose 57 58 /* declarations in increasing order of precedence */ 59 %left ';' 60 %left ',' 61 %left OR 62 %left AND 63 %left EQ NE 64 %left '+' 65 %right '!' 66 67 %% 68 69 input: expr { *root = $1; } 70 ; 71 72 expr: STRING { 73 $$ = malloc(sizeof(Expr)); 74 $$->fn = Literal; 75 $$->name = $1; 76 $$->argc = 0; 77 $$->argv = NULL; 78 $$->start = @$.start; 79 $$->end = @$.end; 80 } 81 | '(' expr ')' { $$ = $2; $$->start=@$.start; $$->end=@$.end; } 82 | expr ';' { $$ = $1; $$->start=@1.start; $$->end=@1.end; } 83 | expr ';' expr { $$ = Build(SequenceFn, @$, 2, $1, $3); } 84 | error ';' expr { $$ = $3; $$->start=@$.start; $$->end=@$.end; } 85 | expr '+' expr { $$ = Build(ConcatFn, @$, 2, $1, $3); } 86 | expr EQ expr { $$ = Build(EqualityFn, @$, 2, $1, $3); } 87 | expr NE expr { $$ = Build(InequalityFn, @$, 2, $1, $3); } 88 | expr AND expr { $$ = Build(LogicalAndFn, @$, 2, $1, $3); } 89 | expr OR expr { $$ = Build(LogicalOrFn, @$, 2, $1, $3); } 90 | '!' expr { $$ = Build(LogicalNotFn, @$, 1, $2); } 91 | IF expr THEN expr ENDIF { $$ = Build(IfElseFn, @$, 2, $2, $4); } 92 | IF expr THEN expr ELSE expr ENDIF { $$ = Build(IfElseFn, @$, 3, $2, $4, $6); } 93 | STRING '(' arglist ')' { 94 $$ = malloc(sizeof(Expr)); 95 $$->fn = FindFunction($1); 96 if ($$->fn == NULL) { 97 char buffer[256]; 98 snprintf(buffer, sizeof(buffer), "unknown function \"%s\"", $1); 99 yyerror(root, error_count, buffer); 100 YYERROR; 101 } 102 $$->name = $1; 103 $$->argc = $3.argc; 104 $$->argv = $3.argv; 105 $$->start = @$.start; 106 $$->end = @$.end; 107 } 108 ; 109 110 arglist: /* empty */ { 111 $$.argc = 0; 112 $$.argv = NULL; 113 } 114 | expr { 115 $$.argc = 1; 116 $$.argv = malloc(sizeof(Expr*)); 117 $$.argv[0] = $1; 118 } 119 | arglist ',' expr { 120 $$.argc = $1.argc + 1; 121 $$.argv = realloc($$.argv, $$.argc * sizeof(Expr*)); 122 $$.argv[$$.argc-1] = $3; 123 } 124 ; 125 126 %% 127 128 void yyerror(Expr** root, int* error_count, const char* s) { 129 if (strlen(s) == 0) { 130 s = "syntax error"; 131 } 132 printf("line %d col %d: %s\n", gLine, gColumn, s); 133 ++*error_count; 134 } 135 136 int parse_string(const char* str, Expr** root, int* error_count) { 137 yy_switch_to_buffer(yy_scan_string(str)); 138 return yyparse(root, error_count); 139 } 140