Function ensureCoverageMapLoaded

src/Common/CoverageCollection.cpp:60–87

std::once_flag g_coverage_map_once;

void ensureCoverageMapLoaded()
{
    std::call_once(g_coverage_map_once, []
    {
        const auto regions = readLLVMCoverageMapping("/proc/self/exe");
        g_coverage_map.reserve(regions.size());
        for (const CoverageRegion & r : regions)
        {
            const CoverageKey key{r.name_hash, r.func_hash, r.counter_id};
            auto [it, inserted] = g_coverage_map.emplace(key, r);
            if (!inserted)
            {
                /// Keep the narrowest region for this counter.  Prefer branch regions
                /// over code regions of the same width — they carry directional info.
                const uint32_t existing_width = it->second.line_end - it->second.line_start;
                const uint32_t new_width      = r.line_end - r.line_start;
                if (new_width < existing_width
                    || (new_width == existing_width && r.is_branch && !it->second.is_branch))
                    it->second = r;
            }
        }

        LOG_INFO(
            getLogger("CoverageCollection"),
            "Loaded {} counter regions from LLVM coverage mapping ({} raw regions)",
            g_coverage_map.size(), regions.size());
    });
}

} // anonymous namespace