How to use VaRA (Overview)

Overall, VaRA is built for two different usage scenarios:

• Running a static analysis to directly generate analysis result either during compile time or in a post processing step.

• Running a dynamic analysis, by instrumeting the binary during compile time and then later producing the analysis data during execution.

Currently, VaRA implements two high-level concepts and some accompanying analysis pipelines for them, one for analyzing repository meta-data and one for analyzing software features, both are described below in more detail.

• Highlight Analysis

• Repository Analysis

• Feature Analysis

Highlight Analysis

• Highlight Region
• Highlight-Interaction Analysis

Repository Analysis

• Commit-Interaction Analysis

Feature Analysis

• Feature Performance Analysis

Instrumentations

VaRA can automatically add instrumentation code around detected regions. To enable this, specify a region detection strategy, enable the tracing code with CXX_FLAGS += -fsanitize=vara and specify the wanted instrumention code with -fvara-instr=INSTR_TYPE.

• Printing Instrumentation (print)
• Clock Time Measurements (clock)
• Trace-Event Format (trace_event)
• Performance-Influence Model Trace (perf_infl_trace)
• Instrumentation Verifier (instr_verify)
• USDT Probe Instrumentations (usdt/usdt_raw)