1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*
* 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.
*/
#ifndef _EXPRESSION_H
#define _EXPRESSION_H
#include <unistd.h>
#include <memory>
#include <string>
#include <vector>
// Forward declaration to avoid including "otautil/error_code.h".
enum ErrorCode : int;
enum CauseCode : int;
struct State {
State(const std::string& script, void* cookie);
// The source of the original script.
const std::string& script;
// Optional pointer to app-specific data; the core of edify never
// uses this value.
void* cookie;
// The error message (if any) returned if the evaluation aborts.
// Should be empty initially, will be either empty or a string that
// Evaluate() returns.
std::string errmsg;
// error code indicates the type of failure (e.g. failure to update system image)
// during the OTA process.
ErrorCode error_code;
// cause code provides more detailed reason of an OTA failure (e.g. fsync error)
// in addition to the error code.
CauseCode cause_code;
bool is_retry = false;
};
enum ValueType {
VAL_INVALID = -1,
VAL_STRING = 1,
VAL_BLOB = 2,
};
struct Value {
ValueType type;
std::string data;
Value(ValueType type, const std::string& str) :
type(type),
data(str) {}
};
struct Expr;
using Function = Value* (*)(const char* name, State* state,
const std::vector<std::unique_ptr<Expr>>& argv);
struct Expr {
Function fn;
std::string name;
std::vector<std::unique_ptr<Expr>> argv;
int start, end;
Expr(Function fn, const std::string& name, int start, int end) :
fn(fn),
name(name),
start(start),
end(end) {}
};
// Evaluate the input expr, return the resulting Value.
Value* EvaluateValue(State* state, const std::unique_ptr<Expr>& expr);
// Evaluate the input expr, assert that it is a string, and update the result parameter. This
// function returns true if the evaluation succeeds. This is a convenience function for older
// functions that want to deal only with strings.
bool Evaluate(State* state, const std::unique_ptr<Expr>& expr, std::string* result);
// Glue to make an Expr out of a literal.
Value* Literal(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
// Functions corresponding to various syntactic sugar operators.
// ("concat" is also available as a builtin function, to concatenate
// more than two strings.)
Value* ConcatFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* LogicalAndFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* LogicalOrFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* LogicalNotFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* SubstringFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* EqualityFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* InequalityFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* SequenceFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
// Global builtins, registered by RegisterBuiltins().
Value* IfElseFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* AssertFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
Value* AbortFn(const char* name, State* state, const std::vector<std::unique_ptr<Expr>>& argv);
// Register a new function. The same Function may be registered under
// multiple names, but a given name should only be used once.
void RegisterFunction(const std::string& name, Function fn);
// Register all the builtins.
void RegisterBuiltins();
// Find the Function for a given name; return NULL if no such function
// exists.
Function FindFunction(const std::string& name);
// --- convenience functions for use in functions ---
// Evaluate the expressions in argv, and put the results of strings in args. If any expression
// evaluates to nullptr, return false. Return true on success.
bool ReadArgs(State* state, const std::vector<std::unique_ptr<Expr>>& argv,
std::vector<std::string>* args);
bool ReadArgs(State* state, const std::vector<std::unique_ptr<Expr>>& argv,
std::vector<std::string>* args, size_t start, size_t len);
// Evaluate the expressions in argv, and put the results of Value* in args. If any
// expression evaluate to nullptr, return false. Return true on success.
bool ReadValueArgs(State* state, const std::vector<std::unique_ptr<Expr>>& argv,
std::vector<std::unique_ptr<Value>>* args);
bool ReadValueArgs(State* state, const std::vector<std::unique_ptr<Expr>>& argv,
std::vector<std::unique_ptr<Value>>* args, size_t start, size_t len);
// Use printf-style arguments to compose an error message to put into
// *state. Returns NULL.
Value* ErrorAbort(State* state, const char* format, ...)
__attribute__((format(printf, 2, 3), deprecated));
// ErrorAbort has an optional (but recommended) argument 'cause_code'. If the cause code
// is set, it will be logged into last_install and provides reason of OTA failures.
Value* ErrorAbort(State* state, CauseCode cause_code, const char* format, ...)
__attribute__((format(printf, 3, 4)));
// Copying the string into a Value.
Value* StringValue(const char* str);
Value* StringValue(const std::string& str);
int parse_string(const char* str, std::unique_ptr<Expr>* root, int* error_count);
#endif // _EXPRESSION_H
|
