Soot (software)

Jimple is an intermediate representation of a Java program designed to be easier to optimize than Java bytecode. It is typed, has a concrete syntax and is based on three-address code.

Jimple includes only 15 different operations, thus simplifying flow analysis. By contrast, java bytecode includes over 200 different operations.{{cite web |url=http://www.sable.mcgill.ca/publications/techreports/#report1 |title=The Jimple Framework |last1=Vallee-Rai |first1=Raja|website=Sable.mcgill.ca |year=1998 }}{{cite web |url=http://www.sable.mcgill.ca/publications/techreports/#report4 |title=Jimple: Simplifying Java Bytecode for Analyses and Transformations |last1=Vallee-Rai |first1=Raja |last2=Hendren |first2=Laurie J.|website=Sable.mcgill.ca |year=1998 }}

Unlike java bytecode, in Jimple local and stack variables are typed and Jimple is inherently type safe.

Converting to Jimple, or "Jimplifying" (after "simplifying"), is conversion of bytecode to three-address code. The idea behind the conversion, first investigated by Clark Verbrugge, is to associate a variable to each position in the stack. Hence stack operations become assignments involving the stack variables.

Consider the following bytecode, which is from the {{Sfn|Vallee-Rai|1998}}

iload 1  // load variable x1, and push it on the stack
iload 2  // load variable x2, and push it on the stack
iadd     // pop two values, and push their sum on the stack
istore 1 // pop a value from the stack, and store it in variable x1

The above translates to the following three-address code:

stack1 = x1 // iload 1
stack2 = x2 // iload 2
stack1 = stack1 + stack2 // iadd
x1 = stack1 // istore 1

In general the resulting code does not have static single assignment form.

Soot is now succeeded by the SootUp framework developed by the Secure Software Engineering Group at Paderborn University.{{cite web |title=A new version of Soot with a completely overhauled architecture |url=https://github.com/soot-oss/SootUp |website=github.com |access-date=16 January 2024}} SootUp is a complete reimplementation of Soot with a novel design, that focuses more on static program analysis, rather than bytecode optimization.

{{Reflist}}

• {{cite conference|year=1998|chapter=Soot: A Java bytecode optimization framework|first1=Raja|last1=Vallée-Rai|first2=Phong|last2=Co|first3=Etienne|last3=Gagnon|first4=Laurie|last4=Hendren|first5=Patrick|last5=Lam|first6=Vijay|last6=Sundaresan|title=Proceedings of the 1999 conference of the Centre for Advanced Studies on Collaborative research |conference=CASCON '99|chapter-url=http://dl.acm.org/citation.cfm?id=782008}} Republished in {{cite conference|title=CASCON First Decade High Impact Papers|conference=CASCON '10|url=http://dl.acm.org/citation.cfm?id=1925818 |pages=214–224 |doi=10.1145/1925805.1925818|url-access=subscription}}
• {{cite conference|year=2000|title=A framework for optimizing Java using attributes|first1=Patrice|last1=Pominville|first2=Feng|last2=Qian|first3=Raja|last3=Vallée-Rai|first4=Laurie|last4=Hendren|first5=Clark|last5=Verbrugge}} Republished in {{cite conference|title=CASCON First Decade High Impact Papers|conference=CASCON '10|url=http://dl.acm.org/citation.cfm?id=1925819 |pages=225–241 |doi=10.1145/1925805.1925819|url-access=subscription}}
• {{cite journal|year=2011|first1=Patrick|last1=Lam|first2=Eric|last2=Bodden|first3=Ondřej|last3=Lhoták|first4=Laurie|last4=Hendren|title=The Soot framework for Java program analysis: a retrospective|journal=Cetus Users and Compiler Infrastructure Workshop|url=http://plg.uwaterloo.ca/~olhotak/pubs/cetus.pdf}}

• {{official website|https://soot-oss.github.io/soot/}}
• [https://scholar.google.com/scholar?cites=9958007337894486876&hl=en Scientific publications citing Soot] (on Google Scholar)

Category:Free software programmed in Java (programming language)

Category:Free computer programming tools

Category:Static program analysis tools

Category:McGill University