SMIILEFinaly COBOL!

and what else is new

Gordana Rakić, Zoran Budimac

Contents Last year... Motivation (why we did it) Related work (what others did) Description (how we did it) Example (how does it work) Conclusion and results. Future work

Last year• First prototype of “universal” software metrics tool

• Characteristics– Platform independency

• Developed in Java Programming Language

– Application range • Two programming languages (Modula-2 and Java)• Two software metrics (CC and LOC)

– Annotated syntax tree based source code and metric values representation - enables

• Source code and metric values history • Language independency of the tool

ContentsLast year…

Motivation (why we did it)

Related work (what others did)

Description (how we did it)

Example (how does it work)

Conclusion and results.

Future work

…Motivation…• Many techniques/tools are appropriate for only one programming language or for one

type of programming languages

• Support of object-oriented metrics is still weak

• Many techniques/tools compute numerical results with no real interpretation of their meanings

• There are no hints and advices what typical actions should be taken in order to improve the software

• The technique/tool should discourage cheating

• Current techniques/tools are not sensitive to the existence of additional code

• Sometimes is not clear which specific software metric have to be applied to accomplish the specific goal.

• PLUS

– Platform dependency

– Support for other metrics

– History of source code

– History of calculated metrics

ContentsLast year …

Motivation (why we did it)

Related work (what others did)

Description (how we did it)

Example (how does it work)

Conclusion and results.

Future work

Related work

• Review of software metric tools available for usage

– Based on testing

• Review of available literature

– Based on• research papers

• available development and product documentation

Review conclusion

Practice needs new tool which

• Is platform independent

• Is programming language independent

• Calculates broad specter of metrics

• Supports keeping of source code history

• Supports keeping of calculated values of software metrics

Contents

Last year…

Motivation (why we did it)

Related work (what others did)

Description (how we did it)

Example (how does it work)

Conclusion and results.

Future work

Description

• The tool description

• Background of universality

• Support for metrics and lanaguages

Parser Generators

• Tool used for generation of language translators

• Input

– language grammar

• Output

– Language scanner

– Language parser

+ Intermediate representation of language constructions

!syntax trees!

Syntax Trees• Syntax Trees

– Intermediate structure produced by • parser generator directly

• translator generated by parser generator

• Represent

– language in abstract form

– concrete source code

– concrete source code elements attached to corresponding abstract language elements

Syntax Trees (2)• Classification of Syntax trees used in this thesis

– Abstract Syntax Tree (AST) represents concrete source code

– Concrete Syntax Tree (CST) represents concrete source code elements attached to corresponding abstract language elements

– Enriched Concrete Syntax Tree (eCST) • Represents concrete source code elements attached to

corresponding abstract language elements

• Contains additional information - universal nodes as markers for language elements figuring in metric algorithms

Description

• The tool description

• Background of universality

• Support for metrics ad languages

Background of universality

• Enriched Concrete Syntax Tree (eCST)

– Generated by Parser generator• Generation is based on programming language grammar

• Enrichment is based on modification of programming language grammar by adding universal nodes into tree

– Stored to XML structure• Enrichment does not effect structure of the tree

– Only content of the tree is affected by these changes

Structure of the eCST

Content of the CST and eCSTUniversal Nodes

IF parenthesizedExpression ifStat = statement(ELSE elseStat = statement -> ^(BRANCH_STATEMENT IF ^(BRANCH ^(IF parenthesizedExpression $ifStat))

^(BRANCH ELSE $elseStat))| -> ^(BRANCH_STATEMENT IF ^(BRANCH ^(IF parenthesizedExpression $ifStat))))

Information flow trough the tool

Description

• The tool description

• Background of universality

• Support for metrics and languages

Current state• In current prototype

– metrics • Cyclomatic Complexity – CC (by predicate counting)• Lines of Code – LOC (by filled lines counting)

– Programming languages • Java• Modula 2 • COBOL

– All calculations and tree transformations in one pass through code

• XML eCST is large for multiple parsing

Adding support for new Programming Language

if (support for new PL is needed) then

begin

modify existing grammar* of new PL (add universal nodes);

generate parser;

add new element in Languages XML structure

end

____________________________________________*Different grammars are supported by different parser generators. As we use ANTLR parser generator in this prototype grammar of new language should be LL(*)

Universal nodes that do not directly affect CC metric

Node \ Language JAVA MODULA-2 COBOL

COMPILATION_UNIT Class MODULE PROGRAM

CONCRETE_UNIT_DECL Concrete Class (IMPLEMENTATION) MODULE

PROCEDURE DIVISION

FUNCTION_DECL Method Declaraton PROCEDURE Procedure

Declaration

MAIN_BLOCK - BEGIN (Of Main Block ) MAINLINE

CONDITION Start of Condition In Branch Statement Or Loop

BRANCH_STATEMENT

Start of Branch Statement (each part will be additionally marked with BRANCH node)

e.g. switch e.g. case e.g. EVALUATE

Universal nodes that directly affect CC metric Node \ Language JAVA MODULA-2 COBOL

BRANCH

ifelse

?:

case defaultcatch

IFELSIF ELSECASE

WHENEND-OF-PAGE

(ON) EXCEPTIONINVALID KEY

(ON) OVERFLOW(ON) SIZE ERROR

IF

JUMP_STATEMENT

breakreturn

continuethrow(s)

EXITRETURN

STOPEXIT

GO-TOGO-BACK

LOOP_STATEMENT

forwhile

repeatdo-while

FORWHILEREPEATLOOP

VARYINGTIMES

PERFORM-UNTIL

LOGICAL_OPERATOR&& ||

ANDOR

ANDOR

ALSO

JUMP_STATEMENT open questions

• Return, break,...

– Are these statements always the jumps?

• GO_TO (and similar statements)

– Could it be improved (maybe by involving the enriched Control Flow Graph - eCFG)?

– Could we distinguish:• JUMP_TO_BACK

• JUMP_TO_FORWARD

Adding support for new Software Metrics

if (support for new Software Metrics is needed) then

begin

determine corresponding new universal nodes;

modify grammars for all supported languages;

regenerate language parsers;

add attribute for storing new metric in XML structure

for storing metric values;

add software metric algorithm implementation in measure class

end

Contents

Last year…

Motivation (why we did it)

Related work (what others did)

Description (how we did it)

Example (how does it work)

Conclusion and results.

Future work

Example

Not today

• For now we used only small example to test grammar and parser, and generation of universal nodes

• It is hard to find appropriate example implemented in all three languages in order to compare results

Contents

Last year…

Motivation (why we did it)

Related work (what others did)

Description (how we did it)

Example (how does it work)

Conclusion and results.

Future work

Results and conclusion

• Motivation and background for development of new software metrics tool which is

– Is platform independent

– Is programming language independent

– Calculates broad specter of metrics

– Supports keeping of source code history

– Supports keeping of calculated values of software metrics

Results and conclusions (2)• Developed prototype of new software metrics tool

which is

– Developed in PL Java

• is platform independent

– Developed to support two input PLs

• Is not programming language independent but base for it is sited

– This year we made one step forward

– Developed to support two Software Metrics

• Specter of metrics is not broad but base for it is sited

– Supports keeping of source code history

– Supports keeping of calculated values of software metrics

! It analyzes single compilation unit stores to single input file

Contents

Last year…

Motivation (why we did it)

Related work (what others did)

Description (how we did it)

Example (how does it work)

Conclusion and results.

Future work

Future work

• Adding support for additional PLs– Ancient PLs – COBOL(almost done) and Fortran ?!

• JUMPS are still open questions here !!!• Support for COBOL is to be tested !!!

• Adding support for additional Software Metrics– For OO metrics relationships between compilation units are

needed !

• Interpret calculated metric values– Represent them graphically– Interpret their meaning in order to provide useful information

to the user

Thank you

Hvala