Created readme

readme.md

+# TFM
+
+- [TFM](#tfm)
+  - [Introduction](#introduction)
+  - [Quick start](#quick-start)
+    - [Build a graph](#build-a-graph)
+    - [Slice a program](#slice-a-program)
+  - [Structure](#structure)
+    - [Summary](#summary)
+  - [Current state](#current-state)
+    - [Graphs](#graphs)
+    - [Statements covered](#statements-covered)
+  - [To do list](#to-do-list)
+    - [SDG](#sdg)
+    - [General](#general)
+  - [Code samples](#code-samples)
+    - [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
+public CFGGraph buildCFG(File programFile) {
+    JavaParser.getStaticConfiguration().setAttributeComments(false); // Always disable comments, just in case
+
+    Node astRoot = JavaParser.parse(programFile);
+
+    return Graphs.CFG.fromASTNode(astRoot); // Creates a new graph representing the program
+}
+```
+
+### Get a slice of the PDG of a program
+
+```java
+public PDGGraph getSlice(File program, SlicingCriterion slicingCriterion) {
+    JavaParser.getStaticConfiguration().setAttributeComments(false); // Always disable comments, just in case
+
+    Node astRoot = JavaParser.parse(programFile);
+
+    PDGGraph pdgGraph = Graphs.PDG.fromASTNode(astRoot);
+
+    return pdgGraph.slice(slicingCriterion);
+}
+
+```
+
+## Workflow
+
+- Branches:
+  - `master` (only for stable versions)
+  - `develop` (main branch)
+  - `<issue number>`
+
+1. Discover a new feature/fix
+2. Open an issue describing it and assign it
+4. Create a new branch from `develop` with the same name as the issue number (e.g. for issue #12 the new branch is called `12`)
+5. Write the solution to the issue
+6. Once resolved, open a pull request from the issue branch to `develop` branch
+7. Finally, when pull request is merged, remove branch
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