-[Build a CFG from a program](#build-a-cfg-from-a-program)
-[Get a slice of the PDG of a program](#get-a-slice-of-the-pdg-of-a-program)
-[Workflow](#workflow)
## Introduction
The main goal of this work is to develop a Java slicer. This is done by building a System Dependence Graph of the program being sliced
## Quick start
### Build a graph
Find `Main` class (`tfm/exec`), modify static fields of the class (the program being analyzed, the graph to build, etc.) and execute it. You will find the output in `tfm/out` as a png image
### Slice a program
Find `Slice` class (`tfm/slicing`), set the program path and execute. The sliced program will be in `tfm/out`
## Structure
Graphs are built using a library called `graphlib`, located in `lib/graphlib.jar`. This library is old and has some issues I had to fix...
The main class is the `Graph` class, which extends from `graphlib`'s `Graph` class. This class includes some behaviour fixes, and some general interest methods (like `toString`, `toGraphvizRepresentation`, etc.)
Every graph has a set of nodes and arrows. `GraphNode` and `Arc` classes are used to represent them respectively.
A set of visitors is implemented for many things, such as graph building, data dependence building, etc... (available in `tfm/visitors`)
A bunch of programs are written in `tfm/programs`, you can write more there.
Some naive testing is implemented in the `tfm/validation` folder. Currently, a PDG can be compared with a program to check their equality.
Some util methods are available in `tfm/utils` (such as AST utils, logger, etc.)
Forget about the `tfm/scopes` folder, it was an idea I had to discard and it has to be deleted.
### Summary
- Graphs (`tfm/graphs`)
- CFGGraph
- PDGGraph
- SDGGraph
- Nodes (`tfm/nodes`)
- ~~CFGNode, PDGNode, SDGNode~~ (_Deprecated_)
- GraphNode
- MethodCallNode (_idk if this is necessary, maybe it can be deleted_)
- Arcs (`tfm/arcs`)
- ControlFlowArc
- DataDependencyArc
- ControlDependencyArc
- Visitors (`tfm/visitors`)
- CFGBuilder
- ~~PDGVisitor~~ (_Deprecated, it was an intent to build a PDG with no CFG needed_)
- PDGBuilder
- ControlDependencyBuilder
- DataDependencyBuilder
- SDGBuilder (_Probably deprecated_)
- NewSDGBuilder -**Work in progress**-
- MethodCallReplacerVisitor (_Replaces method call nodes with in and out variable nodes_) -**Work in progress**-
## Current state
### Graphs
- CFG: Done!
- PDG: Done!
- SDG: PDGs are built for each method
### Statements covered
- Expressions (ExpressionStmt)
- If (IfStmt)
- While, DoWhile (WhileStmt, DoStmt)
- For, Foreach (ForStmt, ForeachStmt)
- Switch (SwitchStmt, SwitchEntryStmt)
- Break (BreakStmt)
- Continue (ContinueStmt)
## To do list
### SDG
- Replace method call nodes with in and out variables nodes and build arrows for them
- Build summary arrows
### General
- Switch to a (much) better graph library like [JGraphT](https://jgrapht.org/). It also supports graph visualization
- Performance review
- Make a test suite (test graph building, slicing, etc.)
- Add support to more Java language features (lambdas, etc.)
## Code samples
### Build a CFG from a program
```java
publicCFGGraphbuildCFG(FileprogramFile){
JavaParser.getStaticConfiguration().setAttributeComments(false);// Always disable comments, just in case
NodeastRoot=JavaParser.parse(programFile);
returnGraphs.CFG.fromASTNode(astRoot);// Creates a new graph representing the program