CodeQL

Overview

CodeQL is a static code analysis tool.

Developed by Semmle and acquired by GitHub in 2019 Based on research from Oxford University.

CodeQL uses data flow analysis and taint analysis to find:

• Code errors
• Check code quality
• Identify vulnerabilities.

CodeQL generates a database from the source code, which can be queried using a query DSL called QL.

Language Support

• C/C++
• C#
• Go
• Java
• JavaScript
• Kotlin
• Python
• Ruby
• Swift
• TypeScript

Suppressions

Could implement suppression of CodeQL queries, by following the same options and strategies in .NET:

• Per-line suppression with inline comments
• Block suppression with inline comments
• Suppression using attributes on assembly, type, members
• Suppression and restore using directives
• EditorConfig

Examples

[*.{cs,vb}]
dotnet_diagnostic.<rule-ID>.severity = none

#pragma warning disable CA2200 // Rethrow to preserve stack details
        throw e;
#pragma warning restore CA2200 /


[module: SuppressMessage("Design", "CA1055:AbstractTypesDoNotHavePublicConstructors", Scope="member", Target="MyTools.Type..ctor()")]

[assembly: SuppressMessage("Usage", "CA2200:Rethrow to preserve stack details", Justification = "Not production code.", Scope = "member", Target = "~M:MyApp.Program.IgnorableCharacters")]

[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2200:Rethrow to preserve stack details", Justification = "Not production code.")]
private static void IgnorableCharacters()
{
    try
    {
        ...
    }
    catch (Exception e)
    {
        throw e;
    }
}

• Code Analysis Suppressions