Introduction

Ensuring the correct discovery of transactions is a multi-step process that may be complex and time consuming for applications that are not supported out-of-the-box. At the core of CAST transaction discovery algorithm is the understanding of the links between objects discovered during the source code analysis of the target application.

CAST AIP automatically sets up default Dependency Rules when the source code is delivered and set as the current version: the source code objects are scanned for references to other objects and links are created where appropriate. Not all links generated in this fashion are valid and their validation by the CAST AI Admin is therefore required.

Missing links result from the inability to find references between objects and can also occur either because of missing dependencies or because of the presence of frameworks that are not supported out-of the box via an environment profile. In this case, new links may be added by defining new dependencies, custom association rules (using the CAST Reference Pattern tool) and/or new, custom environment profiles developed ad hoc to extend the out-of the box support.

For cross-technology links, External Links will identify and record a link between two objects whose validity cannot be precisely determined. These links are tagged as "dynamic". The CAST AI Admin's inspection of these dynamic links is necessary to determine whether the link in question is legitimate (i.e. valid) or if instead it should be ignored and removed from the Analysis Service.

Which technologies are affected?

• JEE
• .NET
• C, C++.

How to manually inspect Dynamic Links

The Dynamic Link Manager (DLM) tool is accessible from CAST Management Studio and must be used to review the Dynamic Links in the first instance. You can access the DLM from the CAST Management Studio Application editor (Execute tab):

Link state

Links can be in three states:

• To be reviewed: links are in this state when you open the Dynamic Link Manager after the completion of an analysis.
• Ignored: links are in this state when you have ticked them after examination (and it proves to be incorrect or false). By default Ignored links are not displayed in the GUI - toggle the Hide Reviewed Links button to view them.
• Validated: links are in this state when you have marked them as Validated after examination (and it proves to be correct). By default Validated links are not displayed in the GUI - toggle the Hide Reviewed Links button to view them.

Invalid links - how to ignore them 

Invalid links must be "ignored" after reviewing the code that creates the link (by ticking the box next to link):

• Ignore Dynamic Links when:
  • Source code uses a logger information message
  • Basic text displayed in a message box or a frame

These actions will remain valid for the next re-analysis. 

Valid links - how to validate them

Valid links must be "validated" after reviewing the code that creates the link (by right clicking the link and selecting Validate)

• Validate Dynamic Links when:

• code uses a manipulation of SQL queries

• code uses a direct call from a business layer to a database table or function

• code links a client part and a server part of an application
  

These actions will remain valid for the next re-analysis. 

Automated Dynamic Link review

Manually reviewing Dynamic Links (although a legitimate approach) is discouraged as it will not address the underlying cases that triggered the detection in the first place and it can be very time consuming, particularly if you have a large number of dynamic links to review. CAST therefore recommends the use of two options to automate this process as described below.

Parametrization

You can leverage method Parametrization to automatically ignore or validate links when they are created with a parameter of a method. Parameterization rules allow you to automatically exclude Dynamics Links when you re-run the analysis. Moreover, Parametrization rules can be reused in future analyses (via an Environment Profile) thus supporting the automation of the analysis process. CAST provides some default parametrization rules and you can also create your own.

Methods are defined in custom environment profiles, and these custom profiles can be selected in the Dynamic Link Manager:

Dynamic Link rules

Dynamic Link Manager rule files enable you to create XML based filter rules that can be tested via the command line and then applied in the CAST Management Studio GUI at Application, Analysis Unit or Technology level: each time an analysis is then run, the filter rules will be applied, either validating or ignoring links as required.

Example rule

<?xml version="1.0" encoding="utf-8"?>
<dynamicLinksRules xmlns="http://www.castsoftware.com/DlmRulesModel.xsd" >
<rule name="Rule1" action="validate" >
	<scope>
		<application name="app1"/>
		<application name="app2">
			<analysisUnit name="au21"/>
		</application>
		<application name="app2">
			<technology name="J2EE"/>
		</application>
	</scope>
	<calleeName regexp="a2"/>
	<calleeType names="A_Metamodel_Type"/>
	<callerFullName regexp="a4"/>
</rule>

<rule name="Rule2" action="ignore">
	<calleeFullName regexp="a4"/>
</rule>
</dynamicLinksRules>

Enabling rules

To associate your rule file in the CAST Management Studio GUI, do as follows.

Technical notes

Limitation of the DLM source code viewer for C/C++

Viewing Source Code

A C++ link may possibly have several different associated pieces of code (in various files). When a server object is referenced in several files for a same Caller, CAST's Dynamic Link Manager will only display references found in one file.

For example:

<pre>file f1.h :
....
void f(const CString&amp; s = CString(&quot; T1&quot; ) );
...
file f2.cpp
...
void f( const CString&amp; s )
{
//...
LPSTR c = &quot;T1&quot;;
//...
}
...</pre>

In this example, T1 is a server object and function f references T1. The references are spread among two files, f1.h and f2.cpp.

Although there is more than one file that contains references to T1, the Dynamic Link Manager will only display one file (either f1.h or f2.cpp) and highlight all references in it. Thus all references in the other file will not be displayed. In this example, if the file displayed by Dynamic Link Manager is f2.cpp, there will be only one reference highlighted although there is another reference in f1.h. Therefore it can be difficult to decide if links to T1 are valid or should be ignored.

To workaround this problem, you can use the Code Viewer in CAST Enlighten. It displays all bookmarks. This allows dynamic links to be evaluated based on complete information.

Macros

Dynamic links will be created to macros based on the source code that is defined in a macro. However, when examining these dynamic links in the Dynamic Link Manager, the link will appear to originate in the macro and call any corresponding object based only on the strings that are defined in the macro. This is a functional limitation of the analyzer. In order to check the validity of these links, the corresponding file where the macro is defined will need to be opened manually.