SHIELD, short for Systematic Hierarchical Intelligence Ecosystem Layer for Defense, is a tool for defending codebases and improving their resilience. The name is also a small nod to Marvel's S.H.I.E.L.D.
At present, SHIELD provides repeatable native benchmarking, hierarchical execution profiling, persistent results, and comparisons between collected runs. A client exposes named benchmark callbacks; the SHIELD shell then selects a benchmark and profile, collects samples, and renders the result. Native runs measure timing and available operating-system counters, including retired instructions and cycles per instruction when the platform exposes them. Optional Callgrind profiles reveal instruction, cache, data-access, and branch behaviour without contaminating native timing.
When an iteration must restore reusable state, surround that work with shield_execution_frame_pause() and shield_execution_frame_resume(). Paused work contributes to neither native timing/resource metrics nor Callgrind instrumentation, so a benchmark can isolate the operation it intends to compare. Pause and resume apply to the currently open frame and must be paired before that frame ends.
Callgrind profiles are intentionally separate from native benchmark collection. SHIELD disables execution frames, native timing, resource metrics, and frame telemetry for the complete benchmark lifecycle. It runs setup, starts Callgrind only for the benchmark callback, then runs teardown. The resulting profile is therefore Callgrind data normalized by the registered work-unit count, rather than a native benchmark report collected under Valgrind. Frame pause/resume calls remain available solely to suspend and resume Callgrind collection.
In the future, SHIELD will extend this defensive role to testing, validation, and related forms of codebase analysis. Its long-term direction also includes cross-language intelligence reasoning.
Register a benchmark in the client, then serve it to SHIELD:
static NError parse_documents(void *user_data, uint64 iteration_count) {
uint64 iteration_index;
for (iteration_index = 0; iteration_index < iteration_count; iteration_index++) {
/* Parse one representative document. */
}
return NEXUS_ERROR_NONE;
}
ShieldBenchmark benchmark;
nexus_memory_bytes_clear(&benchmark, NEXUS_SIZEOF(benchmark));
benchmark.name = "parse-documents";
benchmark.description = "Parse the representative document corpus.";
benchmark.work_unit_label = "documents";
benchmark.work_unit_count_per_iteration = 1;
benchmark.run = parse_documents;
NEXUS_ASSERT(shield_benchmark_register(benchmark) == NEXUS_ERROR_NONE);
return shield_benchmark_client_serve();Run that client through the shell with a directory in which SHIELD may persist the resulting measurements:
shield --results-dir <directory> <client> [client_argument ...]
The interactive result workflow keeps benchmark and Callgrind profile results as independent entities. results lists both kinds in chronological order with their timestamps, IDs, and benchmark metadata labels. save persists every current result by default. A selector list can save a smaller set with save <id|index ...>.
With no arguments, load loads every .shield manifest from the configured results directory. Pass one or more paths to load only those manifests:
load
load <result.shield> [result.shield...]
The raw .callgrind file is the profile visualization artifact rather than a SHIELD result manifest. Use open-profile <id|index> to open it after loading the corresponding profile result.
Delete an in-memory result and its manifest and profile artifact, when present, using its current result-list index:
delete <result-index>
Benchmark and profile comparisons are deliberately separate. With no selectors they compare every compatible in-memory result of that kind. Explicit selectors may be result IDs or current list indices. Results are grouped by benchmark metadata label, sorted by recorded time, and the oldest compatible result is the baseline:
compare-benchmark [result-id|index ...]
compare-profile [result-id|index ...]
For development, clone every dependency individually.
For releases, these dependencies are packaged together with SHIELD.
Contributions are welcome through pull requests.