github.com/cuiweixie/go-ethereum@v1.8.2-0.20180303084001-66cd41af1e38/core/vm/stack_table.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package vm
    18  
    19  import (
    20  	"fmt"
    21  
    22  	"github.com/ethereum/go-ethereum/params"
    23  )
    24  
    25  func makeStackFunc(pop, push int) stackValidationFunc {
    26  	return func(stack *Stack) error {
    27  		if err := stack.require(pop); err != nil {
    28  			return err
    29  		}
    30  
    31  		if stack.len()+push-pop > int(params.StackLimit) {
    32  			return fmt.Errorf("stack limit reached %d (%d)", stack.len(), params.StackLimit)
    33  		}
    34  		return nil
    35  	}
    36  }
    37  
    38  func makeDupStackFunc(n int) stackValidationFunc {
    39  	return makeStackFunc(n, n+1)
    40  }
    41  
    42  func makeSwapStackFunc(n int) stackValidationFunc {
    43  	return makeStackFunc(n, n)
    44  }