C++ BFFIterator::IsAtEnd方法代码示例

// ParseImportDirective
//------------------------------------------------------------------------------
bool BFFParser::ParseImportDirective( const BFFIterator & directiveStart, BFFIterator & iter )
{
	iter.SkipWhiteSpace();

	// make sure we haven't hit the end of the file
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( directiveStart );
		return false;
	}

	// make sure this is a variable name
	if ( iter.IsAtValidVariableNameCharacter() == false )
	{
		Error::Error_1013_UnexpectedCharInVariableName( iter, nullptr );
		return false;
	}

	// find the end of the variable name
	const BFFIterator varNameStart( iter );
	iter.SkipVariableName();
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}
	const BFFIterator varNameEnd( iter );

	// sanity check it is a sensible length
	size_t varNameLen = varNameStart.GetDistTo( varNameEnd );
	if ( varNameLen > MAX_VARIABLE_NAME_LENGTH )
	{
		Error::Error_1014_VariableNameIsTooLong( iter, (uint32_t)varNameLen, (uint32_t)MAX_VARIABLE_NAME_LENGTH );
		return false;
	}
	AStackString<> varName( varNameStart.GetCurrent(), varNameEnd.GetCurrent() );

	// look for varName in system environment
	AStackString<> varValue;
	uint32_t varHash = 0;
	if ( FBuild::Get().ImportEnvironmentVar( varName.Get(), varValue, varHash ) == false )
	{
		Error::Error_1009_UnknownVariable( varNameStart, nullptr );
		return false;
	}

	// add the dot to variable name
	varName = ".";
	varName.Append( varNameStart.GetCurrent(), varNameLen );

	// import variable in current scope
	BFFStackFrame::SetVarString( varName, varValue, nullptr );
	FLOG_INFO( "Imported <string> variable '%s' with value '%s' from system environment", varName.Get(), varValue.Get() );

	return true;
}

// ParseNamedVariableDeclaration
//------------------------------------------------------------------------------
bool BFFParser::ParseNamedVariableDeclaration( BFFIterator & iter )
{
	// skip over the declaration symbol
	ASSERT( *iter == BFF_DECLARE_VAR_INTERNAL );
	m_LastVarNameStart = iter; // include type token in var name
	iter++;

	// make sure we haven't hit the end of the file
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// make sure immediately after the symbol starts a variable name
	if ( iter.IsAtValidVariableNameCharacter() == false )
	{
		Error::Error_1013_UnexpectedCharInVariableName( iter, nullptr );
		return false;
	}

	// find the end of the variable name
	iter.SkipVariableName();
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}
	m_LastVarNameEnd = iter;

	// sanity check it is a sensible length
	size_t varNameLen = m_LastVarNameStart.GetDistTo( m_LastVarNameEnd );
	if ( varNameLen > MAX_VARIABLE_NAME_LENGTH )
	{
		Error::Error_1014_VariableNameIsTooLong( iter, (uint32_t)varNameLen, (uint32_t)MAX_VARIABLE_NAME_LENGTH );
		return false;
	}

	// find the start of the assignment
	iter.SkipWhiteSpaceAndComments();
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	return ParseVariableDeclaration( iter, m_LastVarNameStart, m_LastVarNameEnd );
}

// ParseDefineDirective
//------------------------------------------------------------------------------
bool BFFParser::ParseDefineDirective( BFFIterator & iter )
{
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// parse out token
	const BFFIterator tokenStart( iter );
	iter.SkipVariableName();
	if ( tokenStart.GetCurrent() == iter.GetCurrent() )
	{
		Error::Error_1007_ExpectedVariable( iter, nullptr );
		return false;
	}
	const BFFIterator tokenEnd( iter );

	AStackString<> token( tokenStart.GetCurrent(), tokenEnd.GetCurrent() );

	if ( BFFMacros::Get().Define( token ) == false )
	{
		Error::Error_1038_OverwritingTokenInDefine( tokenStart );
		return false;
	}

	FLOG_INFO( "Define macro <%s>", token.Get() );

	return true;
}

// ParseNamedVariableName
//------------------------------------------------------------------------------
/*static*/ bool BFFParser::ParseVariableName( BFFIterator & iter, AString & name, bool & parentScope )
{
	// skip over the declaration symbol
	ASSERT( *iter == BFF_DECLARE_VAR_INTERNAL ||
			*iter == BFF_DECLARE_VAR_PARENT );

	parentScope = ( *iter == BFF_DECLARE_VAR_PARENT );

	const BFFIterator varNameStart = iter; // include type token in var name
	iter++;

	// make sure we haven't hit the end of the file
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// make sure immediately after the symbol starts a variable name
	if ( iter.IsAtValidVariableNameCharacter() == false )
	{
		Error::Error_1013_UnexpectedCharInVariableName( iter, nullptr );
		return false;
	}

	// find the end of the variable name
	iter.SkipVariableName();
	const BFFIterator varNameEnd = iter;

	// sanity check it is a sensible length
	size_t varNameLen = varNameStart.GetDistTo( varNameEnd );
	if ( varNameLen > MAX_VARIABLE_NAME_LENGTH )
	{
		Error::Error_1014_VariableNameIsTooLong( iter, (uint32_t)varNameLen, (uint32_t)MAX_VARIABLE_NAME_LENGTH );
		return false;
	}

	// store variable name
	name.Assign( varNameStart.GetCurrent(), varNameEnd.GetCurrent() );

	if ( parentScope )
	{
		// exchange '^' with '.'
		ASSERT( BFF_DECLARE_VAR_PARENT == name[0] );
		name[0] = BFF_DECLARE_VAR_INTERNAL;
	}

	return true;
}

// ParseNamedVariableDeclaration
//------------------------------------------------------------------------------
bool BFFParser::ParseNamedVariableDeclaration( BFFIterator & iter )
{
	const BFFIterator varNameStart( iter );

	bool parentScope = false;
	if ( ParseVariableName( iter, m_LastVarName, parentScope ) == false )
	{
		return false; // ParseVariableName() would have display an error
	}

	// find the start of the assignment
	iter.SkipWhiteSpaceAndComments();
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// check if points to a previous declaration in a parent scope
	const BFFVariable * parentVar = nullptr;
	m_LastVarFrame = ( parentScope )
		? BFFStackFrame::GetParentDeclaration( m_LastVarName, nullptr, parentVar )
		: nullptr;

    if ( parentScope )
    {
    	// check if a parent definition exists
    	if ( nullptr == m_LastVarFrame )
	    {
	    	Error::Error_1009_UnknownVariable( varNameStart, nullptr );
	    	return false;
	    }

	    ASSERT( nullptr != parentVar );

	    // check if the parent definition is frozen
    	if ( parentVar->Frozen() )
    	{
    		Error::Error_1060_CantModifyFrozenVar( varNameStart, nullptr, parentVar );
	    	return false;
    	}
    }

	return ParseVariableDeclaration( iter, m_LastVarName, m_LastVarFrame );
}

// ParseUndefDirective
//------------------------------------------------------------------------------
bool BFFParser::ParseUndefDirective( BFFIterator & iter )
{
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// parse out token
	const BFFIterator tokenStart( iter );
	iter.SkipVariableName();
	if ( tokenStart.GetCurrent() == iter.GetCurrent() )
	{
		Error::Error_1007_ExpectedVariable( iter, nullptr );
		return false;
	}
	const BFFIterator tokenEnd( iter );

	AStackString<> token( tokenStart.GetCurrent(), tokenEnd.GetCurrent() );

	if ( BFFMacros::Get().Undefine( token ) == false )
	{
		if ( token.BeginsWith( "__" ) )
		{
			Error::Error_1040_UndefOfBuiltInTokenNotAllowed( tokenStart );			
		}
		else
		{
			Error::Error_1039_UnknownTokenInUndef( tokenStart );
		}
		return false;
	}

	FLOG_INFO( "Undefine macro <%s>", token.Get() );

	return true;
}

// ParseIfDirective
//------------------------------------------------------------------------------
bool BFFParser::ParseIfDirective( const BFFIterator & directiveStart, BFFIterator & iter )
{
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	bool negate = false;
	if ( *iter == '!' )
	{
		negate = true; // the condition will be inverted
		iter++; // skip '!'
		iter.SkipWhiteSpace(); // allow whitepace after '!'
		if ( iter.IsAtEnd() )
		{
			Error::Error_1012_UnexpectedEndOfFile( iter );
			return false;
		}
	}

	// parse out condition
	const BFFIterator conditionStart( iter );
	iter.SkipVariableName();
	if ( conditionStart.GetCurrent() == iter.GetCurrent() )
	{
		Error::Error_1007_ExpectedVariable( directiveStart, nullptr );
		return false;
	}
	const BFFIterator conditionEnd( iter );

	// Evaluate the condition
	bool result;
	if ( CheckIfCondition( conditionStart, conditionEnd, result ) == false )
	{
		return false; // CheckIfCondition will have emitted an error
	}

	// #ifndef ?
	if ( negate )
    {
		result = !( result );
    }

	if ( result )
	{
		++s_IfDepth; // Track that we're inside an if block
		return true; // continue parsing like normal
	}

	// Advance iterator past entire #if block
	size_t depth = 1; // handle nested ifs
	while ( depth > 0 )
	{
		// did we hit the end of the file?
		if ( iter.IsAtEnd() )
		{
			(void)directiveStart; // TODO: Show we're looking for matching endif to this
			Error::Error_1012_UnexpectedEndOfFile( iter ); // TODO:B better error for this?
			return false;
		}

		// find the next preprocessor directive
		iter.SkipWhiteSpace();
		if ( *iter == BFF_PREPROCESSOR_START )
		{
			iter++; // skip #
			iter.SkipWhiteSpace(); // allow whitespace between # and directive
			const BFFIterator directiveNameStart( iter );
			while ( iter.IsAtValidDirectiveNameCharacter() )
			{
				iter++;
			}
			const BFFIterator directiveNameEnd( iter );
			AStackString<> directiveName( directiveNameStart.GetCurrent(), directiveNameEnd.GetCurrent() );
			if ( directiveName == "endif" )
			{
				--depth;
			}
			else if ( directiveName == "if" )
			{
				++depth;
			}

			// continue to skip rest of line....
		}

		// skip rest of line
		while ( ( iter.IsAtEnd() == false ) &&
				( *iter != '\r' ) &&
				( *iter != '\n' ) )
		{
			iter++;
		}
	}

	return true;
}

// Parse
//------------------------------------------------------------------------------
bool BFFParser::Parse( BFFIterator & iter )
{
	for (;;)
	{
		iter.SkipWhiteSpace();

		// is this a comment?
		if ( iter.IsAtComment() )
		{
			iter.SkipComment();
			continue;
		}

		const char c = *iter;
		switch ( c )
		{
			case BFF_DECLARE_VAR_INTERNAL:
			case BFF_DECLARE_VAR_PARENT:
			{
				if ( ParseNamedVariableDeclaration( iter ) == false )
				{
					return false;
				}
				continue;
			}
			case BFF_VARIABLE_CONCATENATION:
			case BFF_VARIABLE_SUBTRACTION:
			{
				// concatenation to last used variable
				if ( ParseUnnamedVariableModification( iter ) == false )
				{
					return false;
				}
				continue;
			}
			case BFF_SCOPE_OPEN:
			{
				// start an unnamed scope
				if ( ParseUnnamedScope( iter ) == false )
				{
					return false;
				}
				continue;
			}
			case BFF_PREPROCESSOR_START:
			{
				if ( ParsePreprocessorDirective( iter ) == false )
				{
					return false;
				}
				continue;
			}
			default:
			{
				if ( iter.IsAtValidFunctionNameCharacter() )
				{
					if ( ParseFunction( iter ) == false )
					{
						return false;
					}
					continue;
				}
			}
		}

		iter.SkipWhiteSpace();
		if ( iter.IsAtEnd() == false )
		{
			Error::Error_1010_UnknownConstruct( iter );
			return false;
		}

		break;  // cleanly hit end of file
	}

	return true;
}

// ParseFunction
//------------------------------------------------------------------------------
bool BFFParser::ParseFunction( BFFIterator & iter )
{
	ASSERT( iter.IsAtValidFunctionNameCharacter() );

	// for variables to be used by this function
	BFFStackFrame stackFrame;

	BFFIterator functionNameStart( iter );
	iter.SkipFunctionName();
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// check length
	if ( functionNameStart.GetDistTo( iter ) > MAX_FUNCTION_NAME_LENGTH )
	{
		// if it's too long, then it can't be a valid function
		Error::Error_1015_UnknownFunction( functionNameStart );
		return false;
	}

	// store function name
	AStackString<MAX_FUNCTION_NAME_LENGTH> functionName( functionNameStart.GetCurrent(), iter.GetCurrent() );
	const Function * func = Function::Find( functionName );
	if ( func == nullptr )
	{
		Error::Error_1015_UnknownFunction( functionNameStart );
		return false;
	}
	iter.SkipWhiteSpace();

	if ( func->IsUnique() && func->GetSeen() )
	{
		Error::Error_1020_FunctionCanOnlyBeInvokedOnce( functionNameStart, func );
		return false;
	}
	func->SetSeen();

	FLOG_INFO( "Function call '%s'", functionName.Get() );

	// header, or body?
	bool hasHeader = false;
	BFFIterator functionArgsStartToken( iter );
	BFFIterator functionArgsStopToken( iter );
	if ( *iter == BFF_FUNCTION_ARGS_OPEN )
	{
		// can this function accept a header?
		if ( func->AcceptsHeader() == false )
		{
			Error::Error_1021_UnexpectedHeaderForFunction( iter, func );
			return false;
		}

		// args
		if ( iter.ParseToMatchingBrace( BFF_FUNCTION_ARGS_OPEN, BFF_FUNCTION_ARGS_CLOSE ) == false )
		{
			Error::Error_1022_MissingFunctionHeaderCloseToken( functionArgsStartToken, func );
			return false;
		}
		functionArgsStopToken = iter;
		hasHeader = true;
		iter++; // skip over closing token	
		iter.SkipWhiteSpaceAndComments();
	}

	if ( func->NeedsHeader() && ( hasHeader == false ) )
	{
		Error::Error_1023_FunctionRequiresAHeader( iter, func );
		return false;
	}

	// some functions have no body
	bool hasBody = false;

	BFFIterator functionBodyStartToken( iter );
	BFFIterator functionBodyStopToken( iter );
	if ( func->NeedsBody() )
	{
		// find body
		if ( *iter != BFF_SCOPE_OPEN )
		{
			Error::Error_1024_FunctionRequiresABody( functionNameStart, func );
			return false;
		}

		if ( iter.ParseToMatchingBrace( BFF_SCOPE_OPEN, BFF_SCOPE_CLOSE ) == false )
		{
			Error::Error_1025_MissingScopeCloseToken( functionBodyStartToken, func );
			return false;
		}

		functionBodyStopToken = iter;
		iter++;
		hasBody = true;
	}

//.........这里部分代码省略.........

// ParseVariableDeclaration
//------------------------------------------------------------------------------
bool BFFParser::ParseVariableDeclaration( BFFIterator & iter, const AString & varName, BFFStackFrame * frame )
{
	m_SeenAVariable = true;

	// look for an appropriate operator
	BFFIterator operatorIter( iter );
	bool modification = false;
	if ( *iter == BFF_VARIABLE_ASSIGNMENT )
	{
		// assignment
	}
	else if ( ( *iter == BFF_VARIABLE_CONCATENATION ) ||
			  ( *iter == BFF_VARIABLE_SUBTRACTION ) )
	{
		// concatenation
		modification = true;
	}
	else
	{
		Error::Error_1016_UnexepectedCharFollowingVariableName( iter );
		return false;
	}

	// skip the assignment symbol and whitespace
	iter++;
	iter.SkipWhiteSpaceAndComments();
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	char openToken = *iter;
	char closeToken = 0;
	bool ok = false;
	if ( ( openToken == '"' ) || ( openToken == '\'' ) )
	{
		closeToken = openToken;
		ok = true;
	}
	else if ( openToken == BFF_SCOPE_OPEN )
	{
		closeToken = BFF_SCOPE_CLOSE;
		ok = true;
	}
	else if ( openToken == BFF_STRUCT_OPEN )
	{
		closeToken = BFF_STRUCT_CLOSE;
		ok = true;
	}
	else if ( ( openToken >= '0' ) && ( openToken <= '9' ) )
	{
		if ( modification )
		{
			Error::Error_1027_CannotModify( operatorIter, varName, BFFVariable::VAR_ANY, BFFVariable::VAR_INT );
			return false;
		}

		// integer value?
		BFFIterator startIntValue( iter );
		while ( iter.IsAtEnd() == false )
		{
			iter++;
			if ( ( *iter < '0' ) || ( *iter > '9' ) )
			{
				break; // end of integer
			}
		}
		if ( startIntValue.GetDistTo( iter ) > 10 )
		{
			Error::Error_1018_IntegerValueCouldNotBeParsed( startIntValue );
			return false;
		}
		AStackString<> intAsString( startIntValue.GetCurrent(), iter.GetCurrent() );
		int i = 0;
		if ( sscanf( intAsString.Get(), "%i", &i ) != 1 )
		{
			Error::Error_1018_IntegerValueCouldNotBeParsed( startIntValue );
			return false;
		}
		return StoreVariableInt( varName, i, frame );
	}
	else if ( ( *iter == 't' ) || ( *iter == 'f' ) )
	{
		// might be 'true' or 'false'
		BFFIterator startBoolValue( iter );
		if ( iter.ParseToNext( 'e' ) == true )
		{
			iter++;
			if ( ( startBoolValue.GetDistTo( iter ) <= 5 ) )
			{
				AStackString<8> value( startBoolValue.GetCurrent(), iter.GetCurrent() );
				if ( value == "true" )
				{
					if ( modification )
					{
						Error::Error_1027_CannotModify( operatorIter, varName, BFFVariable::VAR_ANY, BFFVariable::VAR_BOOL );
						return false;
//.........这里部分代码省略.........

// ParseNamedVariableName
//------------------------------------------------------------------------------
/*static*/ bool BFFParser::ParseVariableName( BFFIterator & iter, AString & name, bool & parentScope )
{
	// skip over the declaration symbol
	ASSERT( *iter == BFF_DECLARE_VAR_INTERNAL ||
			*iter == BFF_DECLARE_VAR_PARENT );

	parentScope = ( *iter == BFF_DECLARE_VAR_PARENT );

	const BFFIterator varNameStart = iter; // include type token in var name
	iter++;

	// make sure we haven't hit the end of the file
	if ( iter.IsAtEnd() )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	if ( *iter == '\'' || *iter == '"' )
	{
		// parse the string
		const BFFIterator openToken = iter;
		iter.SkipString( *openToken );
		if ( *iter != *openToken )
		{
			Error::Error_1002_MatchingClosingTokenNotFound( openToken, nullptr, *openToken );
			return false;
		}
		BFFIterator stringStart = openToken;
		stringStart++;

		// unescape and subsitute embedded variables
		AStackString< 256 > value;
		if ( PerformVariableSubstitutions( stringStart, iter, value ) == false )
		{
			return false;
		}
		iter++; // skip close token

		BFFIterator varNameIter( value.Get(), value.GetLength(), iter.GetFileName().Get(), iter.GetFileTimeStamp() );

		// sanity check it is a sensible length
		if ( value.GetLength() + 1/* '.' will be added */  > MAX_VARIABLE_NAME_LENGTH )
		{
			Error::Error_1014_VariableNameIsTooLong( varNameIter, (uint32_t)value.GetLength(), (uint32_t)MAX_VARIABLE_NAME_LENGTH );
			return false;
		}

		// sanity check it is a valid variable name
		while ( varNameIter.IsAtEnd() == false )
		{
			if ( varNameIter.IsAtValidVariableNameCharacter() == false )
			{
				Error::Error_1013_UnexpectedCharInVariableName( varNameIter, nullptr );
				return false;
			}
			varNameIter++;
		}

		// append '.' to variable name
		name = ".";
		name.Append( value );
	}
	else
	{
		// make sure immediately after the symbol starts a variable name
		if ( iter.IsAtValidVariableNameCharacter() == false )
		{
			Error::Error_1013_UnexpectedCharInVariableName( iter, nullptr );
			return false;
		}

		// find the end of the variable name
		iter.SkipVariableName();
		const BFFIterator varNameEnd = iter;

		// sanity check it is a sensible length
		size_t varNameLen = varNameStart.GetDistTo( varNameEnd );
		if ( varNameLen > MAX_VARIABLE_NAME_LENGTH )
		{
			Error::Error_1014_VariableNameIsTooLong( iter, (uint32_t)varNameLen, (uint32_t)MAX_VARIABLE_NAME_LENGTH );
			return false;
		}

		// store variable name
		name.Assign( varNameStart.GetCurrent(), varNameEnd.GetCurrent() );
	}

	ASSERT( name.GetLength() > 0 );
	if ( parentScope )
	{
		// exchange '^' with '.'
		ASSERT( BFF_DECLARE_VAR_PARENT == name[0] );
		name[0] = BFF_DECLARE_VAR_INTERNAL;
	}

	return true;
}