6.3 CFG

A CFG is a fundamental data structure in compiler design and static program analysis, representing all paths that might be traversed through a program during execution.

A CFG consists of the following key components:

• Nodes: Correspond to basic blocks, a straight-line sequence of operations with one entry and one exit point

• Edges: Represent the flow of control from one block to another, including both conditional and unconditional branches

• Start and end nodes: Every CFG has a unique entry node and one or more exit nodes

As an example of a CFG, consider the function to calculate the maximum of two integer numbers that we used as an example before; see Figure 2.5:

1 int max(int a, int b) { 
 
2   if (a > b) 
 

3     return a; 
 
4   return b; 
 
5 }

Figure 6.1: CFG example C++ code: max.cpp

The corresponding CFG can be represented as follows:

Figure 6.2: CFG example for...