3.2 Building the control-flow graph (CFG)

The first phase of the analysis builds the CFG, from the abstract syntax tree (AST). The CFG represents the control flow in the program:

• every node keeps one instruction of the program;
• directed edged connect two nodes a and b $\Leftrightarrow$ b can be executed right after a during the program execution.

The CFG is extended to hold the information collected by the various analyses.