C++ BFFIterator类代码示例

// 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;
}

// ParseUnnamedScope
//------------------------------------------------------------------------------
bool BFFParser::ParseUnnamedScope( BFFIterator & iter )
{
	// find the matching bracket
	BFFIterator scopeStart( iter );
	if ( iter.ParseToMatchingBrace( BFF_SCOPE_OPEN, BFF_SCOPE_CLOSE ) == false )
	{
		Error::Error_1025_MissingScopeCloseToken( scopeStart, nullptr );
		return false;
	}

	// create stack for scope
	BFFStackFrame stackFrame;

	// parse the scoped part
	BFFParser subParser;
	BFFIterator subIter( scopeStart );
	subIter++; // skip opening token
	subIter.SetMax( iter.GetCurrent() ); // limit to closing token
	if ( subParser.Parse( subIter ) == false )
	{
		return false;
	}

	iter++; // skip closing }

	return true;
}

// ParsePreprocessorDirective
//------------------------------------------------------------------------------
bool BFFParser::ParsePreprocessorDirective( BFFIterator & iter )
{
	const BFFIterator directiveStart( iter );

	// skip directive start token
	ASSERT( *iter == BFF_PREPROCESSOR_START );
	iter++;

	// allow whitepace before directive name
	iter.SkipWhiteSpace();

	// start of directive name
	BFFIterator directiveStartIter( iter );

	// find end of directive
	while ( iter.IsAtValidDirectiveNameCharacter() )
	{
		iter++;
	}
	BFFIterator directiveEndIter( iter );

	iter.SkipWhiteSpace();

	// determine directive
	AStackString< MAX_DIRECTIVE_NAME_LENGTH > directive( directiveStartIter.GetCurrent(), directiveEndIter.GetCurrent() );
	if ( directive == "include" )
	{
		return ParseIncludeDirective( iter );
	}
	else if ( directive == "once" )
	{
		FBuild::Get().GetDependencyGraph().SetCurrentFileAsOneUse();
		return true;
	}
	else if ( directive == "define" )
	{
		return ParseDefineDirective( iter );
	}
	else if ( directive == "undef" )
	{
		return ParseUndefDirective( iter );
	}
	else if ( directive == "if" )
	{
		return ParseIfDirective( directiveStart, iter );
	}
	else if ( directive == "endif" )
	{
		return ParseEndIfDirective( directiveStartIter );
	}
	else if ( directive == "import" )
	{
		return ParseImportDirective( directiveStart, iter );
	}

	// unknown
	Error::Error_1030_UnknownDirective( directiveStartIter, directive );
	return false;
}

// CheckIfCondition
//------------------------------------------------------------------------------
bool BFFParser::CheckIfCondition( const BFFIterator & conditionStart, const BFFIterator & conditionEnd, bool & result )
{
	// trim condition
	AStackString<> condition( conditionStart.GetCurrent(), conditionEnd.GetCurrent() );

	result = BFFMacros::Get().IsDefined( condition );

	return true;
}

// 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;
}

// StoreVariableStruct
//------------------------------------------------------------------------------
bool BFFParser::StoreVariableStruct( const AString & name,
									 const BFFIterator & valueStart, const BFFIterator & valueEnd,
									 const BFFIterator & operatorIter,
									 BFFStackFrame * frame )
{
	// are we concatenating?
	if ( *operatorIter == BFF_VARIABLE_CONCATENATION )
	{
		// concatenation of structs not supported
		Error::Error_1027_CannotModify( operatorIter, name, BFFVariable::VAR_STRUCT, BFFVariable::VAR_ANY );
		return false;
	}

	// create stack frame to capture variables
	BFFStackFrame stackFrame;

	// parse all the variables in the scope
	BFFParser subParser;
	BFFIterator subIter( valueStart );
	subIter.SetMax( valueEnd.GetCurrent() ); // limit to closing token
	if ( subParser.Parse( subIter ) == false )
	{
		return false; // error will be emitted by Parse
	}

	// get variables defined in the scope
	const Array< const BFFVariable * > & structMembers = stackFrame.GetLocalVariables();

	// Register this variable
	BFFStackFrame::SetVarStruct( name, structMembers, frame ? frame : stackFrame.GetParent() );
	FLOG_INFO( "Registered <struct> variable '%s' with %u members", name.Get(), structMembers.GetSize() );

	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;
}

// CheckIfCondition
//------------------------------------------------------------------------------
bool BFFParser::CheckIfCondition( const BFFIterator & conditionStart, const BFFIterator & conditionEnd, bool & result )
{
	// trim condition
	AStackString<> condition( conditionStart.GetCurrent(), conditionEnd.GetCurrent() );
	condition.Replace( '\t', ' ' );
	condition.Replace( " ", "" );

	result = false;

	// For now we only support trivial pre-defined expressions - TODO:B Support more complex expressions
	if ( condition == "__WINDOWS__" )
	{
		#if defined( __WINDOWS__ )
			result = true;
		#endif
		return true;
	}
	if ( condition == "__LINUX__" )
	{
		#if defined( __LINUX__ )
			result = true;
		#endif
		return true;
	}
	if ( condition == "__OSX__" )
	{
		#if defined( __OSX__ )
			result = true;
		#endif
		return true;
	}

	// We found an expression we don't understand
	Error::Error_1036_UnknownTokenInIfDirective( conditionStart );
	return false;
}

// 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 );
}

// FormatError
//------------------------------------------------------------------------------
void Error::FormatError( const BFFIterator & iter,
                         uint32_t errNum,
                         const Function * function,
                         const char * message, ... )
{
    ASSERT( message );
    AStackString< 4096 > buffer;

    va_list args;
    va_start(args, message);
    buffer.VFormat( message, args );
    va_end( args );

    // get human readable info about the position of the error
    uint32_t line = 0;
    uint32_t column = 0;
    const char * lineStart = nullptr;
    iter.GetPosInfo( line, column, lineStart );

    // convert to full path and '/'->'\' cleanup
    const AStackString<> fileName( iter.GetFileName() );
    AStackString<> fullPath;
    NodeGraph::CleanPath( fileName, fullPath );

    // deliberately using OUTPUT here to avoid "Error:" in front
    OUTPUT( "%s(%u,%u): FASTBuild Error #%04u - %s%s%s\n",
            fullPath.Get(),
            line,
            column,
            errNum,
            function ? function->GetName().Get() : "",
            function ? "() - " : "",
            buffer.Get() );

    // find the line end
    BFFIterator lineEnd( iter );
    while ( !lineEnd.IsAtEnd() )
    {
        if (( *lineEnd != '\r' ) && ( *lineEnd != '\n' ))
        {
            lineEnd++;
            continue;
        }
        break;
    }

    // if line is too crazy to be useful, don't print anything more
    size_t lineLength = lineEnd.GetCurrent() - lineStart;
    if ( lineLength >= 256 )
    {
        return;
    }

    // print the problematic line
    AString::Copy( lineStart, buffer.Get(), lineLength );
    FLOG_ERROR( "%s", buffer.Get() );

    // point to the specific pos where parsing broke
    // (taking into account tabs)
    char * c = buffer.Get();
    const char * end = c + column - 1;
    for ( ; c < end; ++c )
    {
        if ( *c != '\t' )
        {
            *c = ' ';
        }
    }

    AString::Copy( "^", c, 1 );
    FLOG_ERROR( buffer.Get() );
    AString::Copy( "\\--here", c, 8 );
    FLOG_ERROR( buffer.Get() );
}

// 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;
}

// StoreVariableArray
//------------------------------------------------------------------------------
bool BFFParser::StoreVariableArray( const AString & name,
									const BFFIterator & valueStart, const BFFIterator & valueEnd,
									const BFFIterator & operatorIter,
									BFFStackFrame * frame )
{
	Array< AString > values( 32, true );
	Array< const BFFVariable * > structValues( 32, true );

	// are we concatenating?
	if ( ( *operatorIter == BFF_VARIABLE_CONCATENATION ) ||
		 ( *operatorIter == BFF_VARIABLE_SUBTRACTION ) )
	{
		// find existing
		const BFFVariable * var = BFFStackFrame::GetVar( name, frame );
		if ( var == nullptr )
		{
			Error::Error_1026_VariableNotFoundForModification( operatorIter, name );
			return false;
		}

		// make sure existing is an array
		if ( var->IsArrayOfStrings() )
		{
			// get values to start with
			values = var->GetArrayOfStrings();
		}
		else if ( var->IsArrayOfStructs() )
		{
			// get values to start with
			structValues = var->GetArrayOfStructs();
		}
		else
		{
			// TODO:B Improve this error to handle ArrayOfStructs case
			Error::Error_1027_CannotModify( operatorIter, name, var->GetType(), BFFVariable::VAR_ARRAY_OF_STRINGS );
			return false;
		}
	}

	// Parse array of variables
	BFFIterator iter( valueStart );
	for (;;)
	{
		iter.SkipWhiteSpaceAndComments();

		// end?
		if ( iter.GetCurrent() == valueEnd.GetCurrent() )
		{
			break;
		}

		const char c = *iter;
		if ( ( c == '"' ) || ( c == '\'' ) )
		{
			// a quoted string

			// detect mistmatches
			if ( structValues.IsEmpty() == false )
			{
				// Mixed types in vector
				Error::Error_1034_OperationNotSupported( iter, 
														 BFFVariable::VAR_ARRAY_OF_STRUCTS,
														 BFFVariable::VAR_STRING,
														 operatorIter );
				return false;
			}

			// subtraction not supported on arrays
			if ( *operatorIter == BFF_VARIABLE_SUBTRACTION )
			{
				Error::Error_1034_OperationNotSupported( iter, BFFVariable::VAR_ARRAY_OF_STRINGS, BFFVariable::VAR_STRING, operatorIter );
				return false;
			}

			// a string
			BFFIterator elementValueStart( iter );
			iter.SkipString( c );
			ASSERT( iter.GetCurrent() <= valueEnd.GetCurrent() ); // should not be in this function if string is not terminated
			elementValueStart++; // move to start of actual content
			AStackString< 2048 > elementValue;

			// unescape and subsitute embedded variables
			if ( PerformVariableSubstitutions( elementValueStart, iter, elementValue ) == false )
			{
				return false;
			}

			values.Append( elementValue );

			iter++; // pass closing quote
		}
		else if ( c == BFF_DECLARE_VAR_INTERNAL ||
				  c == BFF_DECLARE_VAR_PARENT )
		{
			const BFFIterator elementStartValue = iter;

			// a variable
			AStackString< MAX_VARIABLE_NAME_LENGTH > varName;
//.........这里部分代码省略.........

// ParseIncludeDirective
//------------------------------------------------------------------------------
bool BFFParser::ParseIncludeDirective( BFFIterator & iter )
{
	// Sanity check include depth to detect cyclic includes
	if ( s_Depth >= 128 )
	{
		Error::Error_1035_ExcessiveDepthComplexity( iter );
		return false;
	}

	// we expect a " quoted string
	if ( *iter != '"' )
	{
		Error::Error_1031_UnexpectedCharFollowingDirectiveName( iter, AStackString<>( "include" ), '"' ); 
		return false;
	}

	BFFIterator stringStart( iter );
	stringStart++; // first actual character

	// find end of string
	if ( iter.ParseToNext( '"' ) == false )
	{
		Error::Error_1012_UnexpectedEndOfFile( iter );
		return false;
	}

	// unescape and substitute variables
	AStackString<> include;
	if ( PerformVariableSubstitutions( stringStart, iter, include ) == false )
	{
		return false;
	}

	iter++; // skip closing quote before returning

	FLOG_INFO( "Including: %s\n", include.Get() );

	// open include

	// 1) Try current directory
	AStackString<> includeToUse;
	if (PathUtils::IsFullPath(include) == false)
	{
		const char * lastSlash = iter.GetFileName().FindLast( NATIVE_SLASH );
		lastSlash = lastSlash ? lastSlash : iter.GetFileName().FindLast( OTHER_SLASH );
		lastSlash = lastSlash ? ( lastSlash + 1 ): iter.GetFileName().Get(); // file only, truncate to empty
		includeToUse.Assign( iter.GetFileName().Get(), lastSlash );
	}
	includeToUse += include;
	AStackString<> includeToUseClean;
	NodeGraph::CleanPath( includeToUse, includeToUseClean );
	FileStream f;
	if ( f.Open( includeToUseClean.Get(), FileStream::READ_ONLY ) == false )
	{
		Error::Error_1032_UnableToOpenInclude( stringStart, includeToUseClean );
		return false;
	}

	// check if include uses "once" pragma
	if ( FBuild::Get().GetDependencyGraph().IsOneUseFile( includeToUseClean ) )
	{
		// already seen, and uses #once : don't include again
		return true;
	}

	uint64_t includeTimeStamp = FileIO::GetFileLastWriteTime( includeToUseClean );

	// read content of include
	const uint32_t fileSize = (uint32_t)f.GetFileSize();
	AutoPtr< char > mem( (char *)ALLOC( fileSize + 1 ) );
	if ( f.Read( mem.Get(), fileSize ) != fileSize )
	{
		Error::Error_1033_ErrorReadingInclude( stringStart, include, Env::GetLastErr() );
		return false;
	}
	mem.Get()[ fileSize ] = '\000'; // sentinel
	BFFParser parser;
	const bool pushStackFrame = false; // include is treated as if injected at this point
	return parser.Parse( mem.Get(), fileSize, includeToUseClean.Get(), includeTimeStamp, pushStackFrame ); 
}

// 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;
}