/*
* 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>
#include "error_code.h"
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 = kNoError;
// cause code provides more detailed reason of an OTA failure (e.g. fsync error)
// in addition to the error code.
CauseCode cause_code = kNoCause;
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
