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
parse_string(const char * str,Expr ** root,int * error_count)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