lwip/contrib/apps/LwipMibCompiler/SharpSnmpLib/Mib/Lexer.cs

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/*
* Created by SharpDevelop.
* User: lextm
* Date: 2008/5/17
* Time: 16:50
*
* To change this template use Tools | Options | Coding | Edit Standard Headers.
*/
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Lextm.SharpSnmpLib.Mib.Elements.Types;
namespace Lextm.SharpSnmpLib.Mib
{
/// <summary>
/// Lexer class that parses MIB files into symbol list.
/// </summary>
public sealed class Lexer
{
private readonly SymbolList _symbols = new SymbolList();
public Lexer(string file)
: this(file, new StreamReader(file))
{
}
public Lexer(string file, TextReader stream)
{
this.Parse(file, stream);
}
public ISymbolEnumerator GetEnumerator()
{
return _symbols.GetSymbolEnumerator();
}
#region Parsing of MIB File
private class ParseParams
{
public string File;
public StringBuilder Temp = new StringBuilder();
public bool StringSection = false;
public bool AssignSection = false;
public bool AssignAhead = false;
public bool DotSection = false;
}
/// <summary>
/// Parses MIB file to symbol list.
/// </summary>
/// <param name="file">File</param>
/// <param name="stream">File stream</param>
private void Parse(string file, TextReader stream)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
ParseParams pp = new ParseParams();
pp.File = file;
string line;
int row = 0;
while ((line = stream.ReadLine()) != null)
{
if (!pp.StringSection && line.TrimStart().StartsWith("--", StringComparison.Ordinal))
{
row++;
continue; // commented line
}
ParseLine(pp, line, row);
row++;
}
}
private void ParseLine(ParseParams pp, string line, int row)
{
line = line + "\n";
int count = line.Length;
for (int i = 0; i < count; i++)
{
char current = line[i];
bool moveNext = Parse(pp, current, row, i);
if (moveNext)
{
break;
}
}
}
private bool Parse(ParseParams pp, char current, int row, int column)
{
switch (current)
{
case '\n':
case '{':
case '}':
case '(':
case ')':
case '[':
case ']':
case ';':
case ',':
case '|':
if (!pp.StringSection)
{
bool moveNext = ParseLastSymbol(pp, row, column);
if (moveNext)
{
_symbols.Add(CreateSpecialSymbol(pp.File, '\n', row, column));
return true;
}
_symbols.Add(CreateSpecialSymbol(pp.File, current, row, column));
return false;
}
break;
case '"':
pp.StringSection = !pp.StringSection;
break;
case '\r':
return false;
default:
if ((int)current == 0x1A)
{
// IMPORTANT: ignore invisible characters such as SUB.
return false;
}
if (Char.IsWhiteSpace(current) && !pp.AssignSection && !pp.StringSection)
{
bool moveNext = ParseLastSymbol(pp, row, column);
if (moveNext)
{
_symbols.Add(CreateSpecialSymbol(pp.File, '\n', row, column));
return true;
}
return false;
}
if (pp.AssignAhead)
{
pp.AssignAhead = false;
ParseLastSymbol(pp, row, column);
break;
}
if (pp.DotSection && current != '.')
{
ParseLastSymbol(pp, row, column);
pp.DotSection = false;
}
if (current == '.' && !pp.StringSection)
{
if (!pp.DotSection)
{
ParseLastSymbol(pp, row, column);
pp.DotSection = true;
}
}
if (current == ':' && !pp.StringSection)
{
if (!pp.AssignSection)
{
ParseLastSymbol(pp, row, column);
}
pp.AssignSection = true;
}
if (current == '=' && !pp.StringSection)
{
pp.AssignSection = false;
pp.AssignAhead = true;
}
break;
}
pp.Temp.Append(current);
return false;
}
private bool ParseLastSymbol(ParseParams pp, int row, int column)
{
if (pp.Temp.Length > 0)
{
Symbol s = new Symbol(pp.File, pp.Temp.ToString(), row, column);
pp.Temp.Length = 0;
if (s.ToString().StartsWith(Symbol.Comment.ToString()))
{
// ignore the rest symbols on this line because they are in comment.
return true;
}
_symbols.Add(s);
}
return false;
}
private static Symbol CreateSpecialSymbol(string file, char value, int row, int column)
{
string str;
switch (value)
{
case '\n':
str = Environment.NewLine;
break;
case '{':
str = "{";
break;
case '}':
str = "}";
break;
case '(':
str = "(";
break;
case ')':
str = ")";
break;
case '[':
str = "[";
break;
case ']':
str = "]";
break;
case ';':
str = ";";
break;
case ',':
str = ",";
break;
case '|':
str = "|";
break;
default:
throw new ArgumentException("value is not a special character");
}
return new Symbol(file, str, row, column);
}
#endregion
#region Static Parse Helper
public static ITypeAssignment ParseBasicTypeDef(IModule module, string name, ISymbolEnumerator symbols, bool isMacroSyntax = false)
{
Symbol current = symbols.NextNonEOLSymbol();
if (current == Symbol.Bits)
{
return new BitsType(module, name, symbols);
}
if (IntegerType.IsIntegerType(current))
{
return new IntegerType(module, name, current, symbols);
}
if (UnsignedType.IsUnsignedType(current))
{
return new UnsignedType(module, name, current, symbols);
}
if (current == Symbol.Opaque)
{
return new OpaqueType(module, name, symbols);
}
if (current == Symbol.IpAddress)
{
return new IpAddressType(module, name, symbols);
}
if (current == Symbol.TextualConvention)
{
return new TextualConvention(module, name, symbols);
}
if (current == Symbol.Octet)
{
Symbol next = symbols.NextNonEOLSymbol();
if (next == Symbol.String)
{
return new OctetStringType(module, name, symbols);
}
symbols.PutBack(next);
}
if (current == Symbol.Object)
{
Symbol next = symbols.NextNonEOLSymbol();
if (next == Symbol.Identifier)
{
return new ObjectIdentifierType(module, name, symbols);
}
symbols.PutBack(next);
}
if (current == Symbol.Sequence)
{
Symbol next = symbols.NextNonEOLSymbol();
if (next == Symbol.Of)
{
return new SequenceOf(module, name, symbols);
}
else
{
symbols.PutBack(next);
return new Sequence(module, name, symbols);
}
}
if (current == Symbol.Choice)
{
return new Choice(module, name, symbols);
}
return new TypeAssignment(module, name, current, symbols, isMacroSyntax);
}
public static void ParseOidValue(ISymbolEnumerator symbols, out string parent, out uint value)
{
parent = null;
value = 0;
Symbol current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.OpenBracket);
Symbol previous = null;
StringBuilder longParent = new StringBuilder();
current = symbols.NextNonEOLSymbol();
longParent.Append(current);
while ((current = symbols.NextNonEOLSymbol()) != null)
{
bool succeeded;
if (current == Symbol.OpenParentheses)
{
longParent.Append(current);
current = symbols.NextNonEOLSymbol();
succeeded = UInt32.TryParse(current.ToString(), out value);
current.Assert(succeeded, "not a decimal");
longParent.Append(current);
current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.CloseParentheses);
longParent.Append(current);
continue;
}
if (current == Symbol.CloseBracket)
{
parent = longParent.ToString();
return;
}
succeeded = UInt32.TryParse(current.ToString(), out value);
if (succeeded)
{
// numerical way
while ((current = symbols.NextNonEOLSymbol()) != Symbol.CloseBracket)
{
longParent.Append(".").Append(value);
succeeded = UInt32.TryParse(current.ToString(), out value);
current.Assert(succeeded, "not a decimal");
}
current.Expect(Symbol.CloseBracket);
parent = longParent.ToString();
return;
}
longParent.Append(".");
longParent.Append(current);
current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.OpenParentheses);
longParent.Append(current);
current = symbols.NextNonEOLSymbol();
succeeded = UInt32.TryParse(current.ToString(), out value);
current.Assert(succeeded, "not a decimal");
longParent.Append(current);
current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.CloseParentheses);
longParent.Append(current);
previous = current;
}
throw MibException.Create("end of file reached", previous);
}
public static ValueRanges DecodeRanges(ISymbolEnumerator symbols)
{
ValueRanges result = new ValueRanges();
Symbol startSymbol = symbols.NextNonEOLSymbol();
Symbol current = startSymbol;
current.Expect(Symbol.OpenParentheses);
while (current != Symbol.CloseParentheses)
{
Symbol value1Symbol = symbols.NextNonEOLSymbol();
if ((value1Symbol == Symbol.Size) && !result.IsSizeDeclaration)
{
result.IsSizeDeclaration = true;
symbols.NextNonEOLSymbol().Expect(Symbol.OpenParentheses);
continue;
}
// check for valid number
Int64? value1 = DecodeNumber(value1Symbol);
if (!value1.HasValue)
{
value1Symbol.Assert(false, "Invalid range declaration!");
}
// process next symbol
ValueRange range;
current = symbols.NextNonEOLSymbol();
if (current == Symbol.DoubleDot)
{
// its a continuous range
Symbol value2Symbol = symbols.NextNonEOLSymbol();
Int64? value2 = DecodeNumber(value2Symbol);
value2Symbol.Assert(value2.HasValue && (value2.Value >= value1.Value), "Invalid range declaration!");
if (value2.Value == value1.Value)
{
range = new ValueRange(value1.Value, null);
}
else
{
range = new ValueRange(value1.Value, value2.Value);
}
current = symbols.NextNonEOLSymbol();
}
else
{
// its a single number
range = new ValueRange(value1.Value, null);
}
// validate range
if (result.IsSizeDeclaration)
{
value1Symbol.Assert(range.Start >= 0, "Invalid range declaration! Size must be greater than 0");
}
result.Add(range);
// check next symbol
current.Expect(Symbol.Pipe, Symbol.CloseParentheses);
}
if (result.IsSizeDeclaration)
{
current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.CloseParentheses);
}
// validate ranges in between
for (int i=0; i<result.Count; i++)
{
for (int k=i+1; k<result.Count; k++)
{
startSymbol.Assert(!result[i].IntersectsWith(result[k]), "Invalid range declaration! Overlapping of ranges!");
}
}
return result;
}
public static Int64? DecodeNumber(Symbol number)
{
Int64 result;
string numString = (number != null) ? number.ToString() : null;
if (!String.IsNullOrEmpty(numString))
{
if (numString.StartsWith("'") && (numString.Length > 3))
{
// search second apostrophe
int end = numString.IndexOf('\'', 1);
if (end == (numString.Length - 2))
{
try
{
switch (numString[numString.Length - 1])
{
case 'b':
case 'B':
result = Convert.ToInt64(numString.Substring(1, numString.Length - 3), 2);
return result;
case 'h':
case 'H':
result = Convert.ToInt64(numString.Substring(1, numString.Length - 3), 16);
return result;
}
}
catch
{
}
}
}
else if (Int64.TryParse(numString, out result))
{
return result;
}
}
return null;
}
public static ValueMap DecodeEnumerations(ISymbolEnumerator symbols)
{
Symbol current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.OpenBracket);
ValueMap map = new ValueMap();
do
{
current = symbols.NextNonEOLSymbol();
string identifier = current.ToString();
current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.OpenParentheses);
current = symbols.NextNonEOLSymbol();
Int64 enumValue;
if (Int64.TryParse(current.ToString(), out enumValue))
{
try
{
// Have to include the number as it seems repeated identifiers are allowed ??
map.Add(enumValue, String.Format("{0}({1})", identifier, enumValue));
}
catch (ArgumentException ex)
{
current.Assert(false, ex.Message);
}
}
else
{
// Need to get "DefinedValue".
}
current = symbols.NextNonEOLSymbol();
current.Expect(Symbol.CloseParentheses);
current = symbols.NextNonEOLSymbol();
} while (current == Symbol.Comma);
current.Expect(Symbol.CloseBracket);
return map;
}
#endregion
}
}