What is the main problem of symbolic execution?

What is the main problem of symbolic execution?

Symbolic execution is harder when the same memory location can be accessed through different names (aliasing). Aliasing cannot always be recognized statically, so the symbolic execution engine can’t recognize that a change to the value of one variable also changes the other.

What is the difference between symbolic and concrete execution?

From what I have understood, “concrete execution” means “the execution of a program with actual input values unlike symbolic execution, which assumes symbolic values to variables, inputs etc.”.

What is symbolic execution in software engineering?

In software testing, symbolic execution is used to generate a test input for each feasible execution path of a program. At the end of a symbolic execution along a feasible execution path of the program, PC is solved using a constraint solver to generate concrete input values.

What is symbolic execution tree?

Path condition is a boolean formula over input variables and describes which conditions must be true in the state. A symbolic execution tree can be used to characterize all execution paths (i.e., state chains). Moreover, a finite symbolic execution tree can represent an infinite number of real executions.

Is Dynamic symbolic execution guaranteed to terminate?

– DSE is guaranteed to terminate. – DSE is complete: if it ever reaches an error, the program can indeed reach that error in some execution.

What is an execution path?

An execution path is a possible flow of control of a program. Each execution path maintains and updates mapping from variables to symbolic expressions during symbolic execution. Control flow statements such as if makes a current execution path diverge into two different execution paths.

What is a path of execution?

Is symbolic execution static analysis?

But static analysis does not have to use symbolic execution. Symbolic execution may be used just to show an expected symbolic result of a computation.

Is DSE guaranteed to terminate?

Which is an advantage of using symbolic execution?

Symbolic execution is used to reason about a program path-by-path which is an advantage over reasoning about a program input-by-input as other testing paradigms use (e.g. Dynamic program analysis ). However, if few inputs take the same path through the program, there is little savings over testing each of the inputs separately.

How does symbolic execution work in an interpreter?

An interpreter follows the program, assuming symbolic values for inputs rather than obtaining actual inputs as normal execution of the program would. It thus arrives at expressions in terms of those symbols for expressions and variables in the program, and constraints in terms of those symbols for the possible outcomes of each conditional branch.

How are file operations implemented in symbolic execution?

In practice, file operations are implemented as system calls in the kernel, and are outside the control of the symbolic execution tool. The main approaches to address this challenge are: Executing calls to the environment directly. The advantage of this approach is that it is simple to implement.

What happens at Line 5 in symbolic execution?

In theory, symbolic execution would fork two paths at line 5 and each path from there on would have its own copy of the file. The statement at line 11 would therefore return data that is consistent with the value of “condition” at line 5.