xcover

eBPF-based functional test coverage profiler that works without instrumenting binaries

TLDR

Start the profiler in daemon mode for a binary

$ xcover run --detach --path /path/to/bin

Wait until it is ready, then run tests

$ /path/to/bin test1
/path/to/bin test2
xcover stop```

**Generate** a JSON coverage report

Check status or stop

$ xcover stop```

xcover uses kernel eBPF uprobes to trace function calls in any compiled ELF binary (Go, C, Rust, etc.) during test execution. No source changes or recompilation with coverage flags are required.It supports daemon mode so you can start tracing, execute arbitrary test suites or manual runs, then stop and obtain a report of which functions were exercised. Stripped Go binaries can still be symbolized via `.gopclntab`; other stripped binaries can use `--debug-path` for a separate debug file.

PARAMETERS

--path EXEPATH_

ELF executable to profile.

--pid PID

Filter by process ID.

--include / --exclude regex

Include or exclude function symbol names.

--scope binary|project

All functions (default) or only the producing Go module's symbols.

--report

Write JSON coverage report (default true on run).

--debug-path path

Separate debug/symbol file for stripped non-Go binaries.

--detach

Run as a background daemon.

COMMANDS

run

Start profiling. Key flags: `--detach`/`-d`, `--path`/`-p`, `--pid`, `--include`/`--exclude` regexes, `--scope` (`binary` or `project` for Go modules), `--report`, `--debug-path`, `--no-build-id-check`, `--verbose`.

wait

Block until the profiler is fully initialized and tracing.

status

Show whether the profiler daemon is running.

stop

Stop the daemon and finalize results/report (`xcover-report.json` when reporting is enabled).

CAVEATS

- Requires a Linux kernel with eBPF support and appropriate permissions (usually root or CAP_BPF).- Stripped binaries need language-specific fallbacks (`.gopclntab` for Go) or separate debug info.- Measures function coverage at the binary level, not line/branch coverage inside functions.- Single-file `go build main.go` binaries lack module metadata; project scope falls back to binary scope.

RESOURCES

Source code · Documentation