scalasca

A static code analysis plugin for the Scala compiler.

Compiling

Use sbt and package to compile the plugin.

Testing

In order to run the unit tests, use SBT's testOnly. Standalone tests can be run using src/standaloneTest. As a first example, you can run ScalaSCA on ScalaSCA's source itself, using the src/autoCheck script.

Run

Once the plugin has been compiled, it can be used as an additional phase for the compiler: scalac -Xplugin:target/scala-XXX/scalasca_XXX-0.1.jar, where XXX stands for the current scala version.

Summary

ScalaSCA has four warning levels, that are displayed in their respective colours, if your terminal supports them:

• Notice (white): for rules of any kind, that do not check the "correctness" of the code. General static analyses (e.g. constant propagation) typically fall into this category
• Warning (yellow): generally used when a rule discovered a potential bug (medium probability)
• Severe warning (dark yellow): used when a rule discovered a potential bug (high probability)
• Fatal (red): used when a rule discovered a piece of code that will crash at runtime, if executed

Rule Error Code	Description	Category
ASS_USELESSASSIGNMENT	(Re-)assignment to val/var has no effect	Bad Practice
MEM_MISSING_RESOURCE_CLOSING	Resource not freed after usage	Bad Practice
CLS_PUBLIC_MUTABLE_FIELDS	Public vars in classes/objects/traits	Bad Practice
MET_DOUBLE_TRIPLE_EQUALS	(Akka.Actor) Use of == vs ===	Dodgy Code
ARI_DIV_BY_ZERO	Divison by 0	Fatal
GEN_UNUSED_CODE_REMOVAL	Removes unused code	General
GEN_BLOCK_CONST_PROP	Propagates constant values	General

Improvements

• BlockConstantPropagation casts to String and Int in Constant val built from other constants. Any clean quasiquotish solution for this (not being able to be lifted to Any)?
• BlockConstantPropagation does not consider arbitrary methods