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Diffstat (limited to 'third_party/nix/src/nix/why-depends.cc')
| -rw-r--r-- | third_party/nix/src/nix/why-depends.cc | 269 |
1 files changed, 0 insertions, 269 deletions
diff --git a/third_party/nix/src/nix/why-depends.cc b/third_party/nix/src/nix/why-depends.cc deleted file mode 100644 index 954d619ef3..0000000000 --- a/third_party/nix/src/nix/why-depends.cc +++ /dev/null @@ -1,269 +0,0 @@ -#include <queue> - -#include <glog/logging.h> - -#include "libmain/shared.hh" -#include "libstore/fs-accessor.hh" -#include "libstore/store-api.hh" -#include "nix/command.hh" - -namespace { -static std::string hilite(const std::string& s, size_t pos, size_t len, - const std::string& colour = ANSI_RED) { - return std::string(s, 0, pos) + colour + std::string(s, pos, len) + - ANSI_NORMAL + std::string(s, pos + len); -} - -static std::string filterPrintable(const std::string& s) { - std::string res; - for (char c : s) { - res += isprint(c) != 0 ? c : '.'; - } - return res; -} -} // namespace - -namespace nix { -struct CmdWhyDepends final : SourceExprCommand { - std::string _package, _dependency; - bool all = false; - - CmdWhyDepends() { - expectArg("package", &_package); - expectArg("dependency", &_dependency); - - mkFlag() - .longName("all") - .shortName('a') - .description( - "show all edges in the dependency graph leading from 'package' to " - "'dependency', rather than just a shortest path") - .set(&all, true); - } - - std::string name() override { return "why-depends"; } - - std::string description() override { - return "show why a package has another package in its closure"; - } - - Examples examples() override { - return { - Example{"To show one path through the dependency graph leading from " - "Hello to Glibc:", - "nix why-depends nixpkgs.hello nixpkgs.glibc"}, - Example{ - "To show all files and paths in the dependency graph leading from " - "Thunderbird to libX11:", - "nix why-depends --all nixpkgs.thunderbird nixpkgs.xorg.libX11"}, - Example{"To show why Glibc depends on itself:", - "nix why-depends nixpkgs.glibc nixpkgs.glibc"}, - }; - } - - void run(ref<Store> store) override { - auto package = parseInstallable(*this, store, _package, false); - auto packagePath = toStorePath(store, Build, package); - auto dependency = parseInstallable(*this, store, _dependency, false); - auto dependencyPath = toStorePath(store, NoBuild, dependency); - auto dependencyPathHash = storePathToHash(dependencyPath); - - PathSet closure; - store->computeFSClosure({packagePath}, closure, false, false); - - if (closure.count(dependencyPath) == 0u) { - LOG(WARNING) << "'" << package->what() << "' does not depend on '" - << dependency->what() << "'"; - return; - } - - auto accessor = store->getFSAccessor(); - - auto const inf = std::numeric_limits<size_t>::max(); - - struct Node { - Path path; - PathSet refs; - PathSet rrefs; - size_t dist = inf; - Node* prev = nullptr; - bool queued = false; - bool visited = false; - }; - - std::map<Path, Node> graph; - - for (auto& path : closure) { - graph.emplace(path, Node{path, store->queryPathInfo(path)->references}); - } - - // Transpose the graph. - for (auto& node : graph) { - for (auto& ref : node.second.refs) { - graph[ref].rrefs.insert(node.first); - } - } - - /* Run Dijkstra's shortest path algorithm to get the distance - of every path in the closure to 'dependency'. */ - graph[dependencyPath].dist = 0; - - std::priority_queue<Node*> queue; - - queue.push(&graph.at(dependencyPath)); - - while (!queue.empty()) { - auto& node = *queue.top(); - queue.pop(); - - for (auto& rref : node.rrefs) { - auto& node2 = graph.at(rref); - auto dist = node.dist + 1; - if (dist < node2.dist) { - node2.dist = dist; - node2.prev = &node; - if (!node2.queued) { - node2.queued = true; - queue.push(&node2); - } - } - } - } - - /* Print the subgraph of nodes that have 'dependency' in their - closure (i.e., that have a non-infinite distance to - 'dependency'). Print every edge on a path between `package` - and `dependency`. */ - std::function<void(Node&, const std::string&, const std::string&)> - printNode; - - const std::string treeConn = "╠═══"; - const std::string treeLast = "╚═══"; - const std::string treeLine = "║ "; - const std::string treeNull = " "; - - struct BailOut {}; - - printNode = [&](Node& node, const std::string& firstPad, - const std::string& tailPad) { - assert(node.dist != inf); - std::cout << fmt("%s%s%s%s" ANSI_NORMAL "\n", firstPad, - node.visited ? "\e[38;5;244m" : "", - !firstPad.empty() ? "=> " : "", node.path); - - if (node.path == dependencyPath && !all && - packagePath != dependencyPath) { - throw BailOut(); - } - - if (node.visited) { - return; - } - node.visited = true; - - /* Sort the references by distance to `dependency` to - ensure that the shortest path is printed first. */ - std::multimap<size_t, Node*> refs; - std::set<std::string> hashes; - - for (auto& ref : node.refs) { - if (ref == node.path && packagePath != dependencyPath) { - continue; - } - auto& node2 = graph.at(ref); - if (node2.dist == inf) { - continue; - } - refs.emplace(node2.dist, &node2); - hashes.insert(storePathToHash(node2.path)); - } - - /* For each reference, find the files and symlinks that - contain the reference. */ - std::map<std::string, Strings> hits; - - std::function<void(const Path&)> visitPath; - - visitPath = [&](const Path& p) { - auto st = accessor->stat(p); - - auto p2 = p == node.path ? "/" : std::string(p, node.path.size() + 1); - - auto getColour = [&](const std::string& hash) { - return hash == dependencyPathHash ? ANSI_GREEN : ANSI_BLUE; - }; - - if (st.type == FSAccessor::Type::tDirectory) { - auto names = accessor->readDirectory(p); - for (auto& name : names) { - visitPath(p + "/" + name); - } - } - - else if (st.type == FSAccessor::Type::tRegular) { - auto contents = accessor->readFile(p); - - for (auto& hash : hashes) { - auto pos = contents.find(hash); - if (pos != std::string::npos) { - size_t margin = 32; - auto pos2 = pos >= margin ? pos - margin : 0; - hits[hash].emplace_back(fmt( - "%s: …%s…\n", p2, - hilite( - filterPrintable(std::string( - contents, pos2, pos - pos2 + hash.size() + margin)), - pos - pos2, storePathHashLen, getColour(hash)))); - } - } - } - - else if (st.type == FSAccessor::Type::tSymlink) { - auto target = accessor->readLink(p); - - for (auto& hash : hashes) { - auto pos = target.find(hash); - if (pos != std::string::npos) { - hits[hash].emplace_back( - fmt("%s -> %s\n", p2, - hilite(target, pos, storePathHashLen, getColour(hash)))); - } - } - } - }; - - // FIXME: should use scanForReferences(). - - visitPath(node.path); - - RunPager pager; - for (auto& ref : refs) { - auto hash = storePathToHash(ref.second->path); - - bool last = all ? ref == *refs.rbegin() : true; - - for (auto& hit : hits[hash]) { - bool first = hit == *hits[hash].begin(); - std::cout << tailPad - << (first ? (last ? treeLast : treeConn) - : (last ? treeNull : treeLine)) - << hit; - if (!all) { - break; - } - } - - printNode(*ref.second, tailPad + (last ? treeNull : treeLine), - tailPad + (last ? treeNull : treeLine)); - } - }; - - try { - printNode(graph.at(packagePath), "", ""); - } catch (BailOut&) { - } - } -}; -} // namespace nix - -static nix::RegisterCommand r1(nix::make_ref<nix::CmdWhyDepends>()); |