Source Code Insertion
Test RealTime - User Guide
Source Code Insertion
Rational's Source Code Insertion (SCI) technology uses instrumentation techniques
that automatically adds special code to the source files under analysis. After
compilation, execution of the code produces SCI dump data for the selected runtime
analysis or automated testing features.
Rational Test RealTime makes extensive use of SCI technology to transparently
produce test and analysis reports on both native and embedded target platforms.
Estimating Instrumentation Overhead
Instrumentation overhead is the increase in the binary size or the execution time of
the instrumented application, which is due to Source Code Insertion (SCI) generated
by the Runtime Analysis features.
Rational's SCI technology is designed to reduce both types of overhead to a bare
minimum. However, this overhead may still impact your application.
The following table provides a quick estimate of the overhead generated by the
product.
Code Coverage Overhead
Overhead generated by the Code Coverage feature depends largely on the coverage
types selected for analysis.
A 48-byte structure is declared at the beginning of the instrumented file.
Depending on the information mode selected, each covered branch is referenced by
an array that uses
·
1 byte in Default mode
·
1 bit in Compact mode
·
4 bytes in Hit Count mode
The actual size of this array may be rounded up by the compiler, especially in
Compact mode because of the 8-bit minimum integral type found in C and C++.
See Information Modes for more information.
Other Specifics:
·
Loops, switch and case statements: a 1-byte local variable is declared for each
instance
·
Modified/multiple conditions: one
n-
byte local array is declared at the
beginning of the enclosing routine, where
n
is the number of conditions
belonging to a decision in the routine
2
