Legacy System Evolution through ModelDriven Program Transformation

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Legacy System Evolution through Model-Driven
Program Transformation

• Jing Zhang and Jeff Grayzhangj, gray _at_
  cis.uab.edu
• http//www.cis.uab.edu/zhangj
• http//www.cis.uab.edu/gray

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Contents

• Motivation Challenges
• Overview of Model-Driven Program Transformation
  (MDPT)
• Case Study and Demo
• Conclusions Future work

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Two-Dimensions of Transformation/Translation

• Horizontal transformation
• Transformation within the same level of
  abstraction
• E.g., Model transformation, code refactoring
• Vertical translation
• Translation, or synthesis, between layers of
  abstraction
• E.g., MIC interpreters, reverse engineering

Vertical transformation needed!!!
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The evolution of the legacy system in terms of
models and source code
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Code Transformation from Models

• Goal Maintain the fidelity between the mapping
  of the model properties and the legacy source
  code
• Challenges Parsing and invasively transforming
  legacy source code from higher-level models
• Solution Model-Driven Program Transformation
  (MDPT)
• Based on the unification of a mature program
  transformation system with a meta-modeling
  environment

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Supporting TechnologiesThe DMS "Software
Reengineering Toolkit"
Symbol Table
AST (Graph)
Source Files (Domain Notation)
Revised Source Files
Lexer/Parser
Declarations
Unparser
AST (Graph)
Attribute Evaluator
Analyzers
Parser Definition

Debug Text
Transforms
Domain
Transformation
Viewer
Definition
Engine
Reader
Procedures
Sequencing Transforms
Language Descriptions

Unparser definitions
Analysis Transform Descriptions Tool
definition
Coded in PARLANSE
Slide borrowed with permission from Semantic
Designs (www.semdesigns.com)
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Supporting TechnologiesModel-Integrated
Computing (MIC)

• Generic Modeling Environment (GME)
• Embedded Systems Modeling Language (ESML)

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Legacy SystemBold Stroke Product Line

• Mission-control software for Boeing military
  aircraft, e.g., F-18 E/F, Harrier, UCAV
• CORBA event-based systems
• Thousands of components implemented in over a
  million lines of C code

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Model-Driven Program Transformation (MDPT)
UpdatedESML models
Interpreter
DMS Transformation Rules
TransformedBoldStroke C Code
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Benefits

• Ensures causal connection between model changes
  and the underlying source code of the legacy
  system
• Assists in legacy evolution from new properties
  specified in models
• Model interpreters generate transformation rules
  to modify source

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Case Study a black box data recorder
default base domain CppVisualCpp6. pattern
LogStmt() statement "log.add(\"data1_\"
data1_) ". pattern LogOnMethodAspect(sstateme
nt_seq) statement_seq " \s \LogStmt\(\) ".
pattern Update(ididentifier) qualified_id
"\id Update". rule log_on_Update(retdecl_sp
ecifier_seq, ididentifier, pparameter_declaratio
n_clause, s statement_seq) function_definition
-gt function_definition "\ret
\Update\(\id\) (\p) \s " -gt "\ret
\Update\(\id\) (\p) \LogOnMethodAspect\(\s\) "
if modsListstatement_seq .s matches
"\statement_seq \LogOnMethodAspect\(\modsList\)"
. rule log_on_Update_cv(retdecl_specifier_seq,
ididentifier, pparameter_declaration_clause,
s statement_seq, cv cv_qualifier_seq)
function_definition -gt function_definition
"\ret \Update\(\id\) (\p) \cv \s " -gt "\ret
\Update\(\id\) (\p) \cv \LogOnMethodAspect\(\s\)
" if modsListstatement_seq .s matches
"\statement_seq \LogOnMethodAspect\(\modsList\)"
. pattern getData1_(ididentifier)
qualified_id "\id getData1_". rule
log_on_getData1_(retdecl_specifier_seq,
ididentifier, pparameter_declaration_clause, s
statement_seq) function_definition -gt
function_definition "\ret
\getData1_\(\id\) (\p) \s " -gt "\ret
\getData1_\(\id\) (\p) \LogOnMethodAspect\(\s\)
" if modsListstatement_seq .s matches
"\statement_seq \LogOnMethodAspect\(\modsList\)"
. rule log_on_getData1__cv(retdecl_specifier_s
eq, ididentifier, pparameter_declaration_clause,
s statement_seq, cv cv_qualifier_seq)
function_definition -gt function_definition
"\ret \getData1_\(\id\) (\p) \cv \s " -gt
"\ret \getData1_\(\id\) (\p) \cv
\LogOnMethodAspect\(\s\) " if
modsListstatement_seq .s matches
"\statement_seq \LogOnMethodAspect\(\modsList\)"
. public ruleset applyrules log_on_Update,
log_on_Update_cv, log_on_getData1_,
log_on_getData1__cv .
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Transformed code fragment
Addlog("data1_" data1_)
Addlog("data1_" data1_)
Addlog("data1_" data1_)
Addlog("data1_" data1_)
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Video DEMO

• Case study a black box data recorder
• Constraint-Specification Aspect Weaver (C-SAW) is
  utilized to weave the "LogOnWrite" strategy
  across multiple components

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Generalization of the control flow for the MDPT
process
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Conclusion

• The model-driven program transformation technique
  is a novel approach for transforming large legacy
  systems from domain-specific models.
• It provides widespread adaptations across
  multiple source files according to the evolving
  model features.

http//www.gray-area.org/Research/C-SAW/
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Future Work

• Support other concerns (e.g. QoS) for
  transforming Bold Stroke
• Generalization of the process for supporting
  legacy system evolution using MDPT
• Experimental evaluation
• Productivity
• Correctness

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Thank you !!!
Questions?