%{
/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory>
#include <string>
#include <vector>
#include <android-base/macros.h>
#include "edify/expr.h"
#include "yydefs.h"
#include "parser.h"
extern int gLine;
extern int gColumn;
void yyerror(std::unique_ptr<Expr>* root, int* error_count, const char* s);
int yyparse(std::unique_ptr<Expr>* root, int* error_count);
struct yy_buffer_state;
void yy_switch_to_buffer(struct yy_buffer_state* new_buffer);
struct yy_buffer_state* yy_scan_string(const char* yystr);
// Convenience function for building expressions with a fixed number
// of arguments.
static Expr* Build(Function fn, YYLTYPE loc, size_t count, ...) {
va_list v;
va_start(v, count);
Expr* e = new Expr(fn, "(operator)", loc.start, loc.end);
for (size_t i = 0; i < count; ++i) {
e->argv.emplace_back(va_arg(v, Expr*));
}
va_end(v);
return e;
}
%}
%locations
%union {
char* str;
Expr* expr;
std::vector<std::unique_ptr<Expr>>* args;
}
%token AND OR SUBSTR SUPERSTR EQ NE IF THEN ELSE ENDIF
%token <str> STRING BAD
%type <expr> expr
%type <args> arglist
%destructor { delete $$; } expr
%destructor { delete $$; } arglist
%parse-param {std::unique_ptr<Expr>* root}
%parse-param {int* error_count}
%define parse.error verbose
/* declarations in increasing order of precedence */
%left ';'
%left ','
%left OR
%left AND
%left EQ NE
%left '+'
%right '!'
%%
input: expr { root->reset($1); }
;
expr: STRING {
$$ = new Expr(Literal, $1, @$.start, @$.end);
}
| '(' expr ')' { $$ = $2; $$->start=@$.start; $$->end=@$.end; }
| expr ';' { $$ = $1; $$->start=@1.start; $$->end=@1.end; }
| expr ';' expr { $$ = Build(SequenceFn, @$, 2, $1, $3); }
| error ';' expr { $$ = $3; $$->start=@$.start; $$->end=@$.end; }
| expr '+' expr { $$ = Build(ConcatFn, @$, 2, $1, $3); }
| expr EQ expr { $$ = Build(EqualityFn, @$, 2, $1, $3); }
| expr NE expr { $$ = Build(InequalityFn, @$, 2, $1, $3); }
| expr AND expr { $$ = Build(LogicalAndFn, @$, 2, $1, $3); }
| expr OR expr { $$ = Build(LogicalOrFn, @$, 2, $1, $3); }
| '!' expr { $$ = Build(LogicalNotFn, @$, 1, $2); }
| IF expr THEN expr ENDIF { $$ = Build(IfElseFn, @$, 2, $2, $4); }
| IF expr THEN expr ELSE expr ENDIF { $$ = Build(IfElseFn, @$, 3, $2, $4, $6); }
| STRING '(' arglist ')' {
Function fn = FindFunction($1);
if (fn == nullptr) {
std::string msg = "unknown function \"" + std::string($1) + "\"";
yyerror(root, error_count, msg.c_str());
YYERROR;
}
$$ = new Expr(fn, $1, @$.start, @$.end);
$$->argv = std::move(*$3);
}
;
arglist: /* empty */ {
$$ = new std::vector<std::unique_ptr<Expr>>;
}
| expr {
$$ = new std::vector<std::unique_ptr<Expr>>;
$$->emplace_back($1);
}
| arglist ',' expr {
UNUSED($1);
$$->push_back(std::unique_ptr<Expr>($3));
}
;
%%
void yyerror(std::unique_ptr<Expr>* root, int* error_count, const char* s) {
if (strlen(s) == 0) {
s = "syntax error";
}
printf("line %d col %d: %s\n", gLine, gColumn, s);
++*error_count;
}
int ParseString(const std::string& str, std::unique_ptr<Expr>* root, int* error_count) {
yy_switch_to_buffer(yy_scan_string(str.c_str()));
return yyparse(root, error_count);
}
