We have already seen Soot's ability to load Java .class files. Soot can output the Jimple representation of classes in a textual format (.jimple files) and reread this textual format back into Soot.
The ability to parsing textual .jimple files is quite handy. For example, a user could output classfiles as .jimple files, tweak these by hand, and then use Soot to parse them and output tweaked bytecode. Soot thus provides a high-level facility for editing class files. Another potential application of the .jimple files is to cache optimized classfiles for future analysis. Soot can, at a later time, read these files back in, and will not need to reoptimize the original classfile. This leads to faster compilation times. Finally, a user, or a software tool, can write a class in the Jimple textual format, use Soot to parse the Jimple, and thus create bytecode.
The Jimple format is self-explanatory. The SableCC grammar for textual Jimple can be found in the source code distribution of Soot; it is called jimple.scc. The following is an fragment of Jimple code:
{
java.lang.String[] r0;
long l0, $l1, $l2, $l3, $l4, $l5, $l6, $l7;
int i0, $i1, $i2, i3;
java.io.PrintStream $r1, $r2, $r3;
r0 := @parameter0: java.lang.String[];
i0 = 0;
$i1 = 33 % 33;
$i2 = $i1 + 2;
if $i2 != 43 goto label0;
i3 = 9;
goto label1;
label0:
i3 = 4;
The default output format for Soot is classfiles. However, Soot can also produce output in other formats, i.e. textual Jimple. To output .jimple files, invoke Soot using the -f jimple command line option. For example,
java soot.Main -f jimple --app test
will output test and dependent classes as .jimple files.
Out of the box, Soot will first look for a classfile to find the definition of a given class; only if this fails will it look for a .jimple definition. The command line option --src-prec jimple (source precedence) instructs Soot to preferentially resolve the class from a .jimple file, falling back on .class files. When resolving, Soot will look for .jimple files using the soot-classpath in the same manner as it does to find .class files. For example, to build on the previous example, the command
java soot.Main --src-prec jimple --app test
will read the class test from the file test.jimple, and its related classes from the other .jimple files produced in the previous step.
For more details on the -f and --src-prec options the user can refer to the Soot command line documentation.
This document was generated using the LaTeX2HTML translator Version 2008 (1.71)
Copyright © 1993, 1994, 1995, 1996,
Nikos Drakos,
Computer Based Learning Unit, University of Leeds.
Copyright © 1997, 1998, 1999,
Ross Moore,
Mathematics Department, Macquarie University, Sydney.
The command line arguments were:
latex2html jimpleParser -split 0 -nonavigation -dir ./
The translation was initiated by Eric Bodden on 2012-01-22