Draft User Manual OOram/SRE Static Reverse Engineering Trygve 1
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1. Figure 3 Collaboration tool illustrating a port representing a temporary variable Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 10 Phase 3 Specify the names of the classes that implement the roles Manual s gt Chapter 5 Phase 3 Specify the names of the classes that implement the roles Manual Give the Static Reverse Engineering command in the collaboration diagram to open the SRE tool shown in Figure 4 Figure 4 SRE tool The obvious class name to associate with a role is the class of the instance it represents as found in the inspection of phase 2 Also consider if you want to include super or sub classes If the role can be played by different objects consider the classes of all these objects in the same manner You will often specify the same classes for different roles This is normal and means that instances of these classes or their subclasses play different roles There are two alternatives for specifying the class names One is to select a From Role in the ReverseEngineering tool while the phase is Specify class names The class names can then be edited in the bottom Text view Acceptance is automatic when you leave the text editor You will be invited to modify the class name specification if it is syntactically incorrect Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 11 Phase 3 Specify the names of the classes that implement the roles Manual s g2. Push the Read analysis button in the SRE tool to read the results of the analysis The message interfaces found in the class analysis are recorded in the role model ports 1 Messages existing in the role model and found in the analysis are marked as being in class and otherwise left unchanged 2 Messages existing in the role model and not found in the analysis are marked as being not in class and otherwise left unchanged 3 New message selectors are kept in the Port 4 Old dummy selectors not found in the analysis are removed See next chapter The SRE phase is then automatically moved to the last phase Edit interfaces Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 16 Phase 7 Edit interfaces Manual s gt Chapter 9 Phase 7 Edit interfaces Manual An SRE tool is shown in figure 8 as it appears in the final phase It is organized in four rows Menu bar The menu bar contains menus for the five lists and the text view From Roles To Roles Interfaces Messages Methods Contents Menu for the first list view Read reverse engineering results Unnecessary Undo Redo Remove all empty interfaces in whole role model Remove all empty paths in whole role model Move all own messages to default interface in selected Port only Menu for the second list view Read reverse engineering results Unnecessary Undo Redo Menu for the Interface list Add interface R
3. a System Requirements model a System Design model and finally a System Implementation In reverse engineering we start with an implementation and develop one or more System Design models that highlight important aspects of the implementation The OOram SRE Smallralk Reverse Engineering product supports the reverse engineering of Smalltalk programs It has two main application areas 1 Recreating the design of old programs The first application area is in the maintenance of Smalltalk applications The program may have been modified during its maintenance phase or its design may not have been fully documented during its development phase In both cases it will be useful to document its design before embarking on major revisions 2 Cleanup after rapid prototyping The second main application area is as a tool in the system development phase Smalltalk is a very expressive language We frequently find it easier to determine the functionality and main algorithms through rapid prototyping than to follow the traditional waterfall process with specification design and implementation We also find that the rapid prototyping approach yelds a better program from its users point of view than the traditional approach The first working prototype is not a product however It may be satisfactory as oberved from the outside but there still remains developing a clean and robust design that covers rare cases and exceptions as well as the main functi
4. empty ports ron ports without messages shown crossed out Filters in Reverse Engineering tool filters on done in class dummy and base 6 It would be useful with some statistics and metrics such as NOT DONE List interfaces sorted on no of messages Show messages selector sent from several ports and or interfaces No of methods role Messages used once only Ports role Sending of messages classified as private List of method overrides 7 Better handling of dummy messages and interfaces Done Dummy messages and interfaces now stored compactly in RMREPort not shown in regular OOram tool 8 Generate self messages Done by defining two collaborating roles with identical associated class names 9 Browse methods from SRE tool if same image Not done use regular Browser 10 Show number of selector occurrences in method source code Done 11 Many redundant refreshes Fixed It was not easy but is now hopefully OK 12 Check if source files exist and are available Done If trouble user is invited to specify Target source file names 13 Remove empty interfaces Done Chose to provide command in SRE tool rather than making it automatic Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 36 TABLE OF CONTENTS Chapter 1 Background and motivation 1 Chapter 2 Overview of the Static Reverse Engineering SRE 2 method Chapter 3 Phase 1 Decide
5. From Roles List of all roles in the role model Select one to study the messages it sends to its collaborators Showing roles with non empty interfaces after filtering only To Roles List of all the selected From Role s collaborator roles Select one to study the interfaces This is equivalent to selecting a port in the collaboration view Showing ports with non empty interfaces after filtering only Interfaces List of interfaces for messages specified from From Role to To Role Automatically generated interfaces are named as one of the corresponding Smalltalk protocol names The list is filtered by the current setting of the filter buttons Showing non empty interfaces after filtering only Messages List of messages in the selected interface The list is filtered by the current setting of the filter buttons Method list The user can toggle between two lists in the rightmost list view Sending Methods The methods in the From Role classes that send the selected message Receiving Methods The methods in the To Role classes that implement the selected message Text view This view is a text view that either shows the class names associated with the selected From Role or the method selected in the rightmost list view The selected message is highlighted as bold text in the method code The presented method was extracted during analysis in the Target Image and the displayed source is read from the Target Image source files The Text vi
6. chosen a different set of roles om Parag raphEdit or Browser Figure 1 Text editing in the Browser NOTE A crossed out port denotes a port with no messages associated with it This is a special notation for the SRE that we find useful when cleaning up the model after analysis re Gara TextView P lt Paragraph Notice that every object you find when inspecting your target object structure is a candidate to be represented as a separate role even if these objects are instances of the same class You ignore the following kinds of objects 1 objects that are outside the scope of your study 2 objects that are adequately represented by an existing role 3 objects that can be considered enclosed in some other role You may want to distinguish between the following kinds of objects 1 essential object The object is represented by a separate role in the role model 2 encapsulated object The object is considered to be hidden within a role in the context of the current area of concern 3 set of objects A set of objects that are indistinguishable in the context of the current area of concern is represented by a single role that corresponds to one typical member of the set An object set is typically accessed through a MANY port The Collection object itself is then considered encapsulated within the From Role Draft User Manual OOram SRE Static Reverse Engineering Tasko
7. self setHeight 0 lineTable lastStop 0 AmaximumRightx startIndex linelndex 1 stoplndex text size compositionScanner self getCompositionScanner startIndex gt stopIndex whileFalse lineRight self nextLineltem startIndex line linelndex with compositionScanner lineTable lineAt linelndex putInformationFromScanner compositionScanner lineRight compositionScanner rightX maximumRightX lt lineRight iffrue maximumRightX lineRight startIndex compositionScanner lineLast 1 linelndex linelndex 1 self updateCompositionHeight lineTable lastStop text size lineTable trimLinesTo linelndex 1 AmaximumRightX Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 35 Feedback from functionality and user interface evaluation s gt Appendix 2 Feedback from functionality and user interface evaluation 1 Image image communication not needed if SRE and Target images the same Done Special command for analysis in same image 2 BOSS dangerous for image image communication Changed to WSReadWriter Incidentally a specification result file size reduced by factor 10 3 User selectable name of communication file Done Same file now used for communication in both directions 4 Feedback during analysis needed Done 5 Should highlight interfaces and messages not found in analysis Done Collaboration tool now highlights such messages and interfaces by italics font Also
8. through an organization of class and method information A full path query identifies a Smalltalk method to be examined Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 28 Sample Role Model s gt App 1 3 Interaction Scenarios App 1 3 1 Scenario Accept Method HaragraphEditor TextView Browser Text Paragraph ee accept doAccept acceptMessage acceptText from acceptText from acceptMethod from newSelectorList changed selector update with from update with update getContents text newText editText setCompositionWidth bae OOO O E resetState Figure 12 Accept Method Scenario There are different accept activities for the different kinds of text handled by the Browser This scenario shows a typical example of accepting a method The new source code is given to the Browser where it is compiled update messages are sent to the dependents the Browser s TextView The TextView tells its Controller that textHasChanged A somewhat indirect way of telling the activity originator something it really knew all the time Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 29 Sample Role Model s gt ParagraphEditor gt gt accept menu messages accept Save the current text of the text being edited as the current acceptable version for purposes of canceling self textHasChanged false model value self text copy TextController gt gt acc
9. Draft User Manual OOram SRE Static Reverse Engineering Trygve 1 April 1996 Chapter 2 contains a short user manual sufficient if you know the OOram SRE method The remaining chapters should be read before your first reverse engineering operation PLEASE READ THE WHOLE REPORT BEFORE TRYING THE TOOL The development activity plan is as follows 0 Project specification DONE 1 Prototype development DONE Trygve 82 5h 2 Evaluation of functionality and user interface DONE Anne Sh Witold 4h Trygve 7h 3 Product programming and program documentation DONE Trygve Program extention cleanup optimization documentation 308 Port from e33x to f15 105 4 Program review Jon Ola 5 Beta test revision and submitting for product release Trygve 6 User documentation Klartekst Client reference Taskon reference OOram SRE document 1 version 2 File D work t12 ooram t12 oo sre t12 960401 sre draftuserdoc rm4 T A S KON Last update 1 Juni 1998 at 11 40 Print generated 1 Juni 1998 at 11 40 Work Environments Taskon Gaustadall en 21 N 0371 Oslo 3 Norway Tel 47 2295 8631 Telefax 47 22 60 44 27 Background and motivation s gt Chapter 1 Background and motivation In the OOram methodology we distinguish between forward and reverse engineering In forward engineering we start with a problem and describe its solution in a series of successively more elaborate models such as a System User model
10. ProtocolList nil true textMode comment ifTrue self nonMetaClass comment aText string self textMode comment newProtocolList nil true false Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 30 Sample Role Model s gt Browser gt gt acceptMethod from private selector functions acceptMethod aText from aController newSelector newSelector self selectedClass compile aText classified protocol notifying aController newSelector nil ifTrue false newSelector selector x ifFalse self newSelectorList newSelector true Browser gt gt newSelectorList selector list newSelectorList initialSelection Set the currently selected message selector to be initialSelection selector initialSelection self changed selector ComposedTextView gt gt update updating update aSymbol The receiver s model has changed its text Update the receiver self updateDisplayContents TextView gt gt update updating update aSymbol If aSymbol partMsg then read the text to edit from the receiver s model and update the display text aSymbol partMsg ifTrue text self getContents displayContents text text ifTrue self newText text self initializeSelection Translate so the selection is visible self positionToSelection selectionShowing true self invalidate ifFalse self resetController ComposedTextView gt gt getContents m
11. The composition width includes any space taken up by indentation compositionHeight lt Smallinteger gt The height of the composition fitWidth lt Boolean gt True if the composed text was created shrink to fit fontPolicy lt FontPolicy gt The place where fonts are obtained lineTable lt LineInformationT able gt text lt Text gt wordWrap lt Boolean gt The flag to indicate whether word wrapping is turned on Class Variables DefaultCompositionWidth lt Smallinteger gt used for composition unless otherwise specified ComposedText gt gt characterBlockAtPoint character location characterBlockAtPoint aPoint Answer a CharacterBlock for characters in the text at point aPoint Aself getCharacterBlockScanner characterBlockAtPoint aPoint in self Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 34 Sample Role Model s gt ComposedText gt gt characterBlockForlndex character location characterBlockForIndex targetIndex Answer a CharacterBlock for character in the text at targetIndex The coordinates in the CharacterBlock are in the coordinates of the receiver self getCharacterBlockScanner characterBlockForlndex targetIndex in self ComposedText gt gt composeAll accessing composeAll Compose a collection of characters into a collection of lines startIndex stopIndex linelndex maximumRightX compositionScanner lineTable self newLineTable maximumRightX 0 text size 0 ifTrue
12. al OOram SRE Static Reverse Engineering Taskon 1998 Page 13 Phase 4 Write an analysis specification file Automatic s gt The tool asks the user for the communication file name as shown in figure 7 and then writes the specification to this file Notice that the file must be written to a directory that is available in both the SRE and the Target images Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 14 Phase 5 Perform analysis in target image Automatic s gt Chapter 7 Phase 5 Perform analysis in target image Automatic If the Target Image is a different image you must ensure that the SREAnalyzer module has been filed in The filein is in the SRE directory it is called sre3 st The analysis is done by Do it the following expression RMAnModel1 analyzeFromFile in the Target Image The analyzer reads the specification file reveng rev performs the analysis and rewrites the same file with the combined specification and result If the Target Image is the same as the SRE Image you can push the text editor command Analyze this image to perform the analysis and read the result of the analysis in a single operation The SRE tool then automatically transfer to the Edit results phase Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 15 Phase 6 Read the result file into the SRE image Automatic s gt Chapter 8 Phase 6 Read the result file into the SRE image Automatic
13. e Message Paste the text from the shared buffer over the current selection and redisplay if necessary If the shift key is down present the user with a menu of the last few selections replace Message Open the find replace dialog If the user picks Cancel then do nothing If the user picks Find default then so a search If the user picks FindAndReplace then do a search and if found replace undo Message Reset the state of the paragraph prior to the previous cut or paste edit Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 27 Sample Role Model s gt App 1 2 The Roles Browser frod TextView set gt lt va Paragraph 1 Text Class Text handles protocol for treating strings of characters as displayable characters that can have emphasis and font changes The emphasis codes indicate abstract changes in character appearance Actual display is performed in the presence of a TextAttributes which indicates for each abstract code an actual font to be used 2 Paragraph TextLines is the abstract superclass for classes that display lines of stylized text Class ComposedText provides the support for creating modifying and displaying stylized text 3 TextView A ComposedTextView represents a Text The Text should not be changed by any editing unless the user issues the accept command Thus an instances provides a working copy of the Text This copy is edited When the user issues th
14. e accept command the Text is copied from the working version or if the user issues the cancel command the working version is restored from the Text TextView is a pluggable view of text The notion of pluggable views is to provide a view that can be plugged onto any object rather than having to define a new subclass specific to every kind of object that needs to be viewed The chief mechanism is a set of selectors which can be thought of as an adaptor to convert the generic TextView operations into model specific operations such as textMenu See the protocol adaptor for use of the pluggable selectors See the creation messages in the class for an explication of the various parameters Browse senders of the creation messages in the class for examples in the system It also includes support for setting the initial selection to a part of the text 4 ParagraphEditor Class ParagraphEditor contains the main handling of text editing It ought to be used only on smallish texts As a subclass of the ParagraphEditor class TextController uses Menus for model control protocol It also makes a stab localMenultem at the problem of distinguishing user control directed at the model from that directed at the view controller This controller is more tightly connected to its view for example it asks it for its yellowButtonMenu because the view is the current site for pluggable parameterization 5 Browser A browser represents a hierarchical query path
15. e information can be often cached but make sure you clear the cache whenever appropriate 5 Look for inherent inefficiencies in storage If the same information is stored repeatedly in many roles you should consider delegating the storing to a common role An exception is when you use caching to improve speed You must them take great care to maintain consistency Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 25 Discussion s gt Chapter 11 Discussion A detailed report of the sample role model is given in Appendix 1 We see that there is no interface from Browser to TextView this is as expected since we did not include the MVC classes in the analysis View and Object Model The analysis did not find an interface from TextView to Browser This is bad since there are clearly relevant messages in this interface The TextView is a pluggable and these essential message selectors are store in instance variables and sent by perform Returning to the TextView object inspected in the Target Image we found that the interesting messages were text acceptText from and textMenu We could have found these messages by studying the class comment see Chapter 4 We see that there is a rich interface from TextView to Paragraph Closer study may offer opportunities for simplification We also see that there is an even richer interface from ParagraphEditor to TextView These complex interfaces are strong indicators t
16. ect pointers to important collaborators rather than executing elaborate navigational algorithms to find them Hard to compute information can be often cached but make sure you clear the cache whenever appropriate Look for inherent inefficiencies in storage If the same information is stored repeatedly in many roles you should consider delegating the storing to a common role An exception is when you use caching to improve speed You must them take great care to maintain consistency Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 5 Phase 1 Decide on the area of concern Manual s gt Chapter 3 Phase 1 Decide on the area of concern Manual As an example we will study the Text editing facilities of a Smalltalk program Browser in our current image the SRE Image We want to understand the Text editor specialization of the Model View Controller MVC but we do not include the basic MVC framework as such Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 6 Phase 2 Determine role model collaboration structure Manual s gt Chapter 4 Phase 2 Determine role model collaboration structure Manual We interrupted the operation of a Browser found the TextView object and inspected its instance variables We decided that the phenomenon under study was adequately described by the role structure of Figure 1 This was the personal judgment of the analyst another analyst could have
17. emove interface All gt Default change state all messages in selected interface All gt Done change state all messages in selected interface All gt Dummy change state all messages in selected interface Find message select from all messages in all interfaces Undo Redo Menu for the message list gt Default change state selected message gt Done transform selected message into regular message gt Dummy change state selected message Reset Status change state selected message Undo Redo Remove message Menu for the Methods list toggle to senders toggle contents of method list toggle to receivers toggle contents of method list Menu for the bottom text view The view is read only so there is only one active command Copy Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 17 Phase 7 Edit interfaces Manual s gt Filter row Four toggle buttons for filtering interfaces and messages on certain properties Show In Model Messages defined in the role model in the normal way are shown if the button is ON suppressed if it is OFF Show In Class Messages found during Target Image analysis are shown if the button is ON suppressed if it is OFF Show Dummy Messages moved to dummy are shown if the button is ON suppressed if it is OFF Include Base Base model messages are included if the button is ON suppressed if it is OFF Listrow A browser like sequence of lists for navigating in the model
18. ept menu messages accept self textHasChanged and model changeRequestFrom view ifFalse view flash self doAccept ifTrue self textHasChanged false ifFalse view flash TextController gt gt doAccept private doAccept Send the accept message to the model Answer what the model answers acceptMsg acceptMsg view acceptMessage acceptMsg nil ifTrue view flash false acceptMsg numArgs 1 ifTrue one arg selectors get text only model perform acceptMsg with self text ifFalse two arg selectors get text and controller as well model perform acceptMsg with self text with self TextView gt gt acceptMessage adaptor acceptMessage Answer the message sent to the model on accept SacceptMsg Browser gt gt acceptT ext from dolt accept explain acceptText aText from aController Text has been changed Store or compile the text depending on the current mode of the receiver textMode classDefinition ifTrue self acceptClass aText from aController textMode methodDefinition ifTrue self acceptMethod aText from aController textMode categories ifTrue Cursor wait showWhile organization changeFromString aText string self newCategoryList category true textMode protocols ifTrue self selectedClass organization changeFromString aText string self selectedClass reorganize self selectedClass logOrganizationChange self textMode protocol new
19. ess newText aText Set aText to be the text model for the receiver aText nil ifTrue self newText Text new self editText aText ComposedTextView gt gt editText model access editText aText The paragraph to be displayed is created from the characters in aString self isOpen ifTrue displayContents setCompositionWidth self wrappingBox width displayContents text aText asText copy ifFalse displayContents setCompositionWidth ComposedText defaultCompositionWidth displayContents setText aText asText copy self setToTop startBlock stopBlock nil selectionShowing true self controller Make sure we have a controller self resetController self changedPreferredBounds nil ComposedText gt gt setCompositionWidth display box accessing setCompositionWidth aSmalllnteger Set the width for composition to be aSmalllnteger Make sure the composition width in not negative The CompositionScanner requires this compositionWidth aSmalllnteger max 0 Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 32 Sample Role Model s gt ComposedText gt gt setText accessing setText aText Set the text without recomposing Invalidate the compositionHeight and lineTable so that recomposition happens later text aText lineTable compositionHeight nil ParagraphEditor gt gt resetState initialize release resetState Establish the initial conditions for editing t
20. ew is therefore read only the usual Browsing commands such as senders implementors and messages are not available Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 18 Phase 7 Edit interfaces Manual s gt Menu Bar Filter row List row Phase buttons Text view 3 iS iS rs iS is iS rs iS iS i fs i hi hs i hi i fs S fs fs S s hs fs s S hs rs hs rs hs s fs fs Ets Figure 8 Browsing message senders finding a dummy Figure 8 shows a typical example of a dummy message The doitReceiver message is sent from a Browser method and is implemented by a Controller class Inspecting the method we find that the message is actually sent to self We therefore give the gt Dummy Interface command in the Messages list menu to move the message out of the way The filter setting is typical for the cleanup operation Show In Model Show Dummy and Include Base are OFF Show In Class is ON The lists then only show messages that have not yet been considered Notice that a message is a dummy message only if there is no method that sends it to the To Role Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 19 Phase 7 Edit interfaces Manual s gt Figure 9 Browsing message senders finding a proper message The example shown in figure 9 is a typical proper message We see that ParagraphEdito
21. explain _ Browser gt gt newSelectorList Selector list Browser gt gt text text ComposedText gt gt characterBlockAtPoint character location ComposedText gt gt characterBlockForIndex character location ComposedText gt gt composeAll accessing ComposedText gt gt setComposition Width display box accessing ComposedText gt gt setText accessing ComposedTextView gt gt editText model access ComposedTextView gt gt getContents model access ComposedTextView gt gt newText model access ComposedTextView gt gt update updating ControllerWithMenu gt gt performer accessing oo cece ce eeeseeeeeee ParagraphEditor gt gt accept menu messages ParagraphEditor gt gt evaluator private ParagraphEditor gt gt resetS tate initialize release TextController gt gt accept menu messages TextController gt gt doAccept private TextController gt gt model model access 0 0 0 0 0 occ cce tec cette estes TextView gt gt acceptMessage adaptor TextView gt gt getContents model access TextView gt gt update updating Draft User Manual OOram SRE Static Reverse Engineering lt i gt
22. f the separation of concern has been successful Create an intelligent documentation A model dump such as the one shown in Appendix 1 is usually too boring to be really informative Try it Careful editing and commenting of the automatically generated report makes it more readable but it also gives you a maintenance problem Consider moving your comments into the model to simplify later maintenance Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 4 Overview of the Static Reverse Engineering SRE method s gt 9 Ifyour task is one of re engineering you will want to consider improvements in the extracted model Some consideration Consider to distribute the work of roles with a great many collaborators A true object oriented system is distributed not centralized Ports with very few messages could be considered for indirect access Send the message to some other role that will forward it Look for unnecessary rigidity caused by objects knowing too much about the object structure i e a method that navigates an object structure and centralizes all the work Consider distributing the work to the objects rather than doing the work for them This simplifies the object structure and prepares the ground for future extentions through specialization subclassing Look for inherent inefficiencies in computation Consider if hard to get information can be stored explicitly It is usually beneficial to maintain dir
23. hat the distribution of attributes and functionality between the ParagraphEditor TextView and Paragraph objects should be reconsidered Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 26 Sample Role Model s gt Appendix 1 Sample Role Model App 1 1 Area of Concern As an example we will study the Text editing facilities of a Smalltalk program Browser in our current image the SRE Image We want to understand the Text editor specialization of the Model View Controller MVC but we do not include the basic MVC framework as such Stimulus messages 1 ParagraphEditor accept Message again Message Text substitution If a shift key is down the substitution is made throughout the entire Paragraph Otherwise only the next possible substitution is made againConfirm Message Text substitution If the left shift key is down the substitution is made throughout the entire Paragraph Otherwise only the next possible substitution is made Prompt to confirm substitution 5 May 1989 trygve lt lt lt 60 gt gt gt 29 December 1990 trygve st4 0 3 April 1992 trygve st4 1 950407 als vw leftShiftDown gt shiftDown cancel Message copySelection Message Copy the current selection and store it in the shared buffer cut Message find Message Open the find dialog If the user picks Cancel then do nothing Otherwise search for the next occurrence of the text from the dialog past
24. he paragraph set the emphasis to that of the first character self resetTypein emphasisHere self text emphasisAt 1 self textHasChanged false App 1 4 Implementation classes NOTE We have deleted most of the code report it is not interesting in the context of the SRE User manual App 1 4 1 Browser implementation Model subclass Browser instanceVariableNames organization category className meta protocol selector textMode classVariableNames CategoryMenu ClassMenu LastProtocol MessageMenu MethodMoveProtocol ProtocolMenu RemoveChangesOnFileOut TextMenu poolDictionaries category TM Browser A browser represents a hierarchical query path through an organization of class and method information A full path query identifies a Smalltalk method to be examined Instance Variables organization lt SystemOrganizer gt category lt String gt a selection from all categories in the organization className lt Symbol gt a selection from all classes in the category meta lt Boolean gt false for viewing instance methods true for class methods protocol lt Symbol gt a selection from all protocols in the class selector lt Symbol gt a selection from all messages in the protocol textMode lt Symbol gt indicating the nature of the currently viewed text Class Variables CategoryMenu lt Menu nil gt of operations on the class categories ClassMenu lt Menu nil gt of operations and queries about a class LastPr
25. l be displayed when ready Considered a role attribute i e an object encapsulated within the TextView role partMsg lt Symbol nil gt the text aspect of the model Inspected value was textMenu It is an important variable It represents a message selector to be sent by the object through a perform it will NOT be found by the analysis algorithm acceptMsg lt Symbol nil gt the message used to accept text Inspected value was textMenu It is an important variable It represents a message selector to be sent by the object through a perform it will NOT be found by the analysis algorithm menuMsg lt Symbol nil gt the message to find a menu in the model Inspected value was textMenu It is an important variable It represents a message selector to be sent by the object through a perform it will NOT be found by the analysis algorithm initialSelectionString lt nil String Text gt nil or a string text whose first occurrence will be initially selected Figure 3 shows the OOram Collaboration tool Note the explanation for the ctr port from Browser to Controller The explanation shows that this is a call back passed as parameter to the Browser The existence and nature of this port could only be determined in phase 7 when we studied the methods sending messages through the port Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 9 Phase 2 Determine role model collaboration structure Manual s gt
26. lease in vermont trygve sre 3 sre3 im2 is the SRE Image This image is an extension of internal Taskon release f15 sre3 stis the analysis filein for the Target Image Note This filein includes the WSReadWriter Use a ChangeList if you file into a Taskon image 2 The Target Image This image is wherever you keep it It could be the SRE Image The Target Image source code files You will want to examine Target Image methods so it should be set up with source code and the source files should be accessible from the SRE Image 4 A file for data communication between the two Images Default file name is reveng rev but you will be invited to specify some other file name Analysis specifications are written by the SRE Image and read by the Target Image The Target Image augments the file with the results of the analysis and the file is finally read by the SRE image to include the results in the design model s The static reverse engineering method consists of 7 phases 1 Decide on the area of concern Manual Even the simplest Smalltalk program is a fairly complex structure of objects that is linked directly or indirectly to every other object in the image You must decide on the domain of the new role model Examples are are an application model structure specific editor model relationships the inner details of an editor and a general mechanism that you want to study for the purposes of creating a new framework Draf
27. lize it is sent and implemented in most classes but is typically only sent to self not to a collaborator If the message is a dummy message move it to the list of dummy messages by one of the commands gt Dummy or All gt Dummy Alternatively you could remove it but it will then reappear when you repeat the analysis 8 Edit roles and collaboration structure Consider port cardinality Ports with no messages should be considered changed into NONE ports Ports with multiple collaborators should be considerd changed into MANY ports Consider path removal Paths with NONE ports at both ends can be removed Edit explanations Explanations for roles and messages have been automatically extracted from class and method comments They should be used as a starting point for commenting the roles in the context of the current role model Edit them to make them describe important features without being overburdened with details We typically include description of purpose and responsibility but exclude details such as the types of parameters and variables Consider separation of concern It may be appropriate to divide a complex model into a number of simpler ones You can either make a number of copies the complex model and simplify them or create simpler base models with the inverse synthesis operation Let each base model cover part of the total scope The total model can be derived from these base models but this is often unnecessary i
28. n 1998 Page 7 Phase 2 Determine role model collaboration structure Manual s gt 4 irrelevant object An object that is considered totally outside the scope of the current area of concern Irrelevant objects may be referenced from environment objects in the current role model A port can represent variables of many different kinds 1 Global variable The port will define the interface to a role representing the corresponding object 2 Class variable The port will define the interface to a role representing the corresponding object 3 Instance variable The port will define the interface to a role representing the corresponding object 4 Method The variable is computed by a method Temporary The variable is a parameter or a temporary variable in a method Always include an abundance of ports in your initial model in order to capture messages sent through temporary variables You can always remove them in the last phase when you are certain of their irrelevance The OOram reverse engineering method prescribes that ALL relevant paths and messages shall be shown in the role model E g the expression a b c should be considered expanded into its constituent parts tl ab t2 tl c We then consider the variables a t1 and t2 The corresponding paths are either considered to be internal to the current role or they must be shown as separate ports as illustrated in Figure 2 Figure 2 Role model for the expressi
29. odel access getContents Answer the text that the receiver is viewing Amodel value TextView gt gt getContents model access getContents text partMsg nil ifTrue Text new text model perform partMsg text nil ifTrue Text new text Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 31 Sample Role Model s gt Browser gt gt text text text text textMode classDefinition ifTrue className nil ifTrue Class template category asText ifFalse self selectedClass definition asText textMode methodDefinition ifTrue selector nil ifTrue self selectedClass sourceCodeTemplate asText ifFalse self selectedClass sourceCodeAt selector as Text makeSelectorBoldin self selectedClass textMode category ifTrue category to add asText textMode categories ifTrue organization printString asText textMode protocol ifTrue protocol to add asText textMode protocols ifTrue self selectedClass organization printString asText textMode comment ifT rue text self selectedClass comment asText text isEmpty ifFalse text self selectedClass isMeta ifTrue Select the browser switch instance to see the comment asText self selectedClass commentTemplateString asText textMode hierarchy ifTrue self selectedClass printHierarchy asText Text new ComposedTextView gt gt newText model acc
30. on a b c Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 8 Phase 2 Determine role model collaboration structure Manual s gt The TextView role represents an instance of the TextView class Inspection of a running Browser revealed the following instance variables the explanations have been copied from the class comments 1 10 11 12 13 container lt Wrapper nil gt the parent object of the receiver aScrollWrapper Considered outside the scope of this study model lt Object gt aBrowser Represented by port m controller lt Controller gt Represented by port c scrollOffset lt ScrollValueHolder gt contains the current scrolling offset and the current scroll grid Considered a role attribute i e an object encapsulated within the TextView role displayContents lt ComposedText gt the visual component to use to show the text Represented by port dC startBlock lt CharacterBlock gt the start selection Considered a role attribute i e an object encapsulated within the TextView role stopBlock lt CharacterBlock gt the stop selection Considered a role attribute i e an object encapsulated within the TextView role selectionShowing lt Boolean gt flag indicating whether the selection is ready to be displayed Considered a role attribute i e an object encapsulated within the TextView role displaySelection lt Boolean gt flag indicating whether selections wil
31. on the area of concern Manual 6 Chapter 4 Phase 2 Determine role model collaboration structure 7 Manual Chapter 5 Phase 3 Specify the names of the classes that H implement the roles Manual Chapter 6 Phase 4 Write an analysis specification file 13 Automatic Chapter 7 Phase 5 Perform analysis in target image Automatic 15 Chapter 8 Phase 6 Read the result file into the SRE image 16 Automatic Chapter 9 Phase 7 Edit interfaces Manual 17 Chapter 10 Phase 8 Edit roles and collaboration structure 24 Chapter 11 DisCussigtictia ticinta onan arie dimer aiaa 720 Appendix 1 Sample Role Model eiee 27 App 1 1 Afex Of Contem esne neg Mo lessee et watt pce raion pon Sea ea Gate saints Y 27 App 1 2 The Roles e ee ce cece te e a E T 28 App 1 3 Interaction Scenarios eeuna n R pitas iene epee ponte itt 29 App 1 3 1 scenario Accept Method merter sg ty be ue ae eee cals tte S 29 Draft User Manual OOram SRE Static Reverse Engineering lt i gt App 1 4 App 1 4 1 App 1 4 2 Appendix 2 Implementation classes Browser implementation ComposedText implementation Feedback from functionality and user interface evaluation 33 33 34 36 Draft User Manual OOram SRE Static Reverse Engineering lt ii gt INDEX Browser gt gt acceptMethod from private selector functions Browser gt gt acceptText from dolt accept explain Browser gt gt doltReceiver dolt accept
32. onality The system also needs to be optimized and the documentation to be completed Early versions of the documentation particularly the user documentation should be developed as part of the rapid prototyping process This document assumes that you are familiar with the OOram methodology particularly with the role collaboration diagram with its ports interfaces and messages Chapter 2 contains a quick guide to the use of OOram SRE It should be sufficient if you already know the OOram SRE method The remaining chapters should be read before you try your first reverse engineering operation Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 1 Overview of the Static Reverse Engineering SRE method s gt Chapter 2 Overview of the Static Reverse Engineering SRE method OOram SRE Static Reverse Engineering is a method for creating a role model collaboration view of an existing Smalltalk application Two Smalltalk images are involved in this method They could as a special case be the same image 1 The SRE Image is the image containing the role modeling tools with the SRE extensions 2 The Target Image contains the application classes under study This image can be any ObjectWorks Smalltalk or VisualWorks image extended with an SREAnalyzer filein It could even be identical to the SRE Image The following files are of interest 1 The OOram SRE programs You find the most current alpha test re
33. otocol lt Symbol nil gt last message category selected Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 33 Sample Role Model s gt MessageMenu lt Menu nil gt of operations on the message categories MethodMoveProtocol lt CharacterArray nil gt last message category used in a move ProtocolMenu lt Menu nil gt of operations and queries about a message RemoveChangesOnFileOut lt Boolean gt flags whether to remove classes from the ChangeSet when they are filed out TextMenu lt Menu nil gt of text editing operations See above for method Browser gt gt acceptMethod from See above for method Browser gt gt acceptText from Browser gt gt doltReceiver dolt accept explain doltReceiver Answer the object that should be informed of the result of evaluating a text selection self nonMetaClass See above for method Browser gt gt newSelectorList See above for method Browser gt gt text App 1 4 2 ComposedText implementation TextLines subclass ComposedText instanceVariableNames text compositionWidth compositionHeight wordWrap fontPolicy lineTable fitWidth classVariableNames DefaultCompositionWidth poolDictionaries TextConstants category Graphics Text Support Class ComposedText provides the support for creating modifying and displaying stylized text Instance Variables compositionWidth lt Smallinteger gt The width of the area in which the text is composed
34. pen an inspector on the Controller We find that self evaluator evaluates to a Browser1 the doltReceiver message is therefore sent to the Browser and is a proper message in this port As acheck we browse the relevant methods and find that the collaboration structure is not always evident from the code ParagraphEditor gt gt evaluator private evaluator Answer the object that defines the context of an evaluation self performer self ifTrue self modell ifFalse self performer ControllerWithMenu gt gt performer accessing performer Answer the receiver of menu messages Aperformer Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 22 Phase 7 Edit interfaces Manual s gt Who sets this value and when We find that it is set to self in the initialize method and that it is modified by the performer method An interesting sender is TextController gt gt model l model access model aModel super model aModel self performer aModel So the evaluator is the performer the performer is the model the model is the Browser role So the doltReceiver message is sent to the Browser Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 23 Phase 8 Edit roles and collaboration structure s gt Chapter 10 Phase 8 Edit roles and collaboration structure The goal of this phase is to manipulate the model in order to make it easier to understand The following hints ma
35. pendix 1 is usually too boring to be really informative Try it Careful editing and commenting of the automatically generated report makes it more readable but it also gives you a maintenance problem Consider moving your comments into the model to simplify later maintenance If your task is one of re engineering you will want to consider improvements in the extracted model Some consideration 1 Consider to distribute the work of roles with a great many collaborators A true object oriented system is distributed not centralized 2 Ports with very few messages could be considered for indirect access Send the message to some other role that will forward it Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 24 Phase 8 Edit roles and collaboration structure s gt 3 Look for unnecessary rigidity caused by objects knowing too much about the object structure i e a method that navigates an object structure and centralizes all the work Consider distributing the work to the objects rather than doing the work for them This simplifies the object structure and prepares the ground for future extentions through specialization subclassing 4 Look for inherent inefficiencies in computation Consider if hard to get information can be stored explicitly It is usually beneficial to maintain direct pointers to important collaborators rather than executing elaborate navigational algorithms to find them Hard to comput
36. r gt gt paragraph sends the message displayContents to the view instance variable that is the variable represented by the TextView lt Controller port By convention we use the Message list command gt Default interface to change its interface to the default interface Notice that a message is a proper message if at least one of the methods send it to the To Role Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 20 Phase 7 Edit interfaces Manual s gt Figure 10 Browsing message senders finding a call back message In the the usual MVC framework the Model does not know the Controller In the example of figure 10 however the Browser Model gets reference to the Controller in a message parameter and uses this knowledge to return messages to the Controller There must therefore be a port from the Browser to the Controller even if its life span is limited to a single method invocation Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 21 Phase 7 Edit interfaces Manual s gt Figure 11 Browsing message senders an obscure case Figure 11 represents a somewhat obscure case The method ParagraphEditor gt gt doltReceiver sends the message doltReceiver to self evaluator but is this one of our roles or is it to be suppressed in our role model We have to revert to the Target Image and investigate in depth An easy way out is to interrupt the execution of a Browser and o
37. s Specifier Tool to trigger the analysis and record the results The Class Specifier Tool will then close and the SRE Tool will go directly to phase 7 Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 3 Overview of the Static Reverse Engineering SRE method s gt 6 Read the result file into the OOram SRE image Automatic Push the Read analysis button in the SRE tool to read the results of the analysis The message interfaces determined by the analysis are recorded in the role model ports and can be inspected in the SRE tool New messages are given an interface name corresponding to the Smalltalk method protocol The new messages are kept in a compact form in the SRE part of the system They are only visible in the SRE Tool and are not visible in the regular OOram tools To make them visible see next phase 7 Edit interfaces Manual In this phase you systematically examine every new message and determine if it is a regular message that is truly sent through the current port or if it is a dummy message If the message is a regular message transform it into a normal OOram message by the one of the commands gt Done gt Default All gt Done or All gt Default The automatically generated interfaces contain many dummy messages i e messages that are implemented in a To Role class and sent from a From Role class but that are not sent through the current port A typical example is the message initia
38. some of the functionality that you want to capture in the role If you do not specify a relevant class you may miss important messages If you specify too many classes your cleanup job in phase 7 will be unnecessarily tedious 4 Write an analysis specification file Automatic Hit the Write specification button in the SRE Class specifier tool This writes a binary file that contains the input data for the interface analysis The SRE tool asks you for the name of the communication file and writes the specification to this file 5 Perform analysis in Target Image Automatic The SREAnalyzer module sre2 st must be filed into the Target Image prior to the analysis The analysis is then done by Dolt the following expression RMVAnModel1 analyzeFromFile The analyzer reads the specification from the file performs the analysis and overwrites the file with the combined specification and analysis results For each specified port the analyzer determines the messages possibly sent from the From Role to the To Role The messages are determined as the intersection between two sets the set of the selectors of all messages sent from the methods of the From Role classes and the set of the selectors of all methods implemented in the To Role classes The analyzer does not find messages sent indirectly such as with the perform command If the Target Image is identical to the SRE Image you can press the Analyze this image button in the SRE Clas
39. t An alternative is to use a special tool Press the button marked Specify class names in the SRE tool This opens the SRE class specifier tool as shown in Figure 5 Figure 5 SRE class specifier tool The class names are written in the fields provided The specified class names are stored in the corresponding role whenever a field has been edited 1 The Undo and Redo buttons work in the usual manner 2 The Write specification button will write a file containing the analysis specification close the tool and transfer to the next phase 3 The Analyze this image button will perform the analysis on the classes in the current image close the tool and transfer to the last Edit interfaces phase 4 If you close the window in any other manner the specified class names will be remembered but the work phase will remain unaltered Push the Specify class names button in the SRE tool to reopen this SRE class specifier tool Draft User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 12 Phase 4 Write an analysis specification file Automatic s gt Chapter 6 Phase 4 Write an analysis specification file Automatic The Write specification button in Figure 5 will close the tool and transfer to the next phase Alternatively you can push the Write specification button in the SRE tool as shown in figure 6 Figure 7 Specify directory for communication between SRE Image and Target Image Draft User Manu
40. t User Manual OOram SRE Static Reverse Engineering Taskon 1998 Page 2 Overview of the Static Reverse Engineering SRE method s gt 2 Determine role model collaboration structure Manual You must identify the objects that are within your domain and represent them in a role model The roles and their collaboration structure are determined manually A good technique is to interrupt the running application in the Target Image and use the Smalltalk inspector to explore the objects choosing suitable roles and their structure Record your model in an OOram Collaboration View in the SRE Image Give the roles meaningful names Create ports for all message communication paths that may be relevant within the scope of your study Use the port explanation to record the name and nature of the variable s represented by the port Make sure to include all ports that may possibly be relevant including ports that represent global variables class variables and computed values such as ObjectMemory current The analysis will not find unspecified paths and will not look for messages sent from NONE ports 3 Specify the names of the classes that implement the roles Manual The collaboration view menu command Static reverse engineering opens the SRE tool Hit the Specify class names button to open the SRE ClassName tool You often specify several classes for one role they may be independent or in a subclass superclass relationship Each class implements
41. y be useful 1 Consider port cardinality Ports with no messages should be considered changed into NONE ports Ports with multiple collaborators should be considerd changed into MANY ports 2 Consider path removal Paths with NONE ports at both ends can be removed 3 Edit explanations Explanations for roles and messages have been extracted from class and method comments They should be used as a starting point for commenting the roles in the context of the current role model Edit them to make them describe important features without being overburdened with details We typically include description of purpose and responsibility but exclude details such as the types of parameters and variables 4 Consider separation of concern It may be appropriate to divide a complex model into a number of simpler ones You can either make a number of copies the complex model and simplify them or create simpler base models with the inverse synthesis operation Let each base model cover part of the total scope The total model can be derived from these base models but this is often unnecessary if the separation of concern has been successful In our text editor example we could have separated out the TextView Paragraph Text part in a separate base model We could also have created a general MVC base model and made the Browser TextView ParagraphEditor into a derived model 5 Create an intelligent documentation A model dump such as the one shown in Ap
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