In computer science, control-flow analysis (CFA) is a static-code-analysis technique for determining the control flow of a program. The control flow is expressed as a control-flow graph (CFG).

What is control-flow analysis? •Data-flow analysis relied on a control-flow graph •How do we construct CFG? •For intra-procedural analysis, relatively straightforward •Identify basic blocks, control-flow structures • We will not delve into this •For inter-procedural analysis •If functions/procedures are not first-class ...

Nov 22, 2024 · A Control Flow Graph (CFG) is the graphical representation of control flow or computation during the execution of programs or applications. Control flow graphs are mostly used in static analysis as well as compiler applications, as they can accurately represent the flow inside a program unit.

Control flow analysis Analyzing program to discover its control structure Today’s topic: CFG-based analysis Control Flow Analysis 3 Control Flow Graph CFG models flow of control in the program (procedure) A basic block is a maximal sequence of G = (N, E) as a directed graph

Control-Flow Graphs •Graphical representation of a program •Edges in graph represent control flow: how execution traverses a program •Nodes represent statements 6 x := 0; y := 0; while (n > 0) {if (n % 2 = 0) {x := x + n; y := y + 1;} else {y := y + n; x := x + 1;} n := n - 1;} print(x); x:=x+n y:=y+1 y := 0 n > 0 n%2=0 y:=y+n print(x) n ...

Control-flow analyses (CFAs) are the class of algorithms that solve the value-flow problem. Because a precise solution is impossible, CFAs compute conservative over-approximations. That is, if a CFA says that the procedure foo is invoked at some call site, then it …

A control-flow analysis is a technique to show how hierarchical flow of control within a given program are sequenced, making all possible execution paths of a program analyzable.

Control flow analysis focuses on those decision points to provide a more intuitive representation of that behaviour, known as control flow graphs (or control flow diagrams). In turn, that helps developers to ensure that the code they have written fulfils their intentions.

Q: Why is control flow analysis important? A: Control flow is a key component of program behavior Control flow analysis – Discovers the flow of control within a procedure – Builds a representation of control flow (loops, etc) January 28, 2015 Control Flow Analysis 10

Analyzing functional programs challenges the framework we’ve discussed so far. Understanding and solving those problems illustrates constraint based analyses and is also closely related to call graph construction in object-oriented languages, as we discussed in the previous lecture.