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-rw-r--r--third_party/nix/src/nix/why-depends.cc433
1 files changed, 206 insertions, 227 deletions
diff --git a/third_party/nix/src/nix/why-depends.cc b/third_party/nix/src/nix/why-depends.cc
index 325a2be0a7..7b8650a4e8 100644
--- a/third_party/nix/src/nix/why-depends.cc
+++ b/third_party/nix/src/nix/why-depends.cc
@@ -1,267 +1,246 @@
+#include <queue>
 #include "command.hh"
-#include "store-api.hh"
-#include "progress-bar.hh"
 #include "fs-accessor.hh"
+#include "progress-bar.hh"
 #include "shared.hh"
-
-#include <queue>
+#include "store-api.hh"
 
 using namespace nix;
 
-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 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) ? c : '.';
-    return res;
+static std::string filterPrintable(const std::string& s) {
+  std::string res;
+  for (char c : s) res += isprint(c) ? c : '.';
+  return res;
 }
 
-struct CmdWhyDepends : 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);
+struct CmdWhyDepends : 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)) {
+      printError("'%s' does not depend on '%s'", package->what(),
+                 dependency->what());
+      return;
     }
 
-    std::string name() override
-    {
-        return "why-depends";
-    }
+    stopProgressBar();  // FIXME
 
-    std::string description() override
-    {
-        return "show why a package has another package in its closure";
-    }
+    auto accessor = store->getFSAccessor();
 
-    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"
-            },
-        };
-    }
+    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;
 
-    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);
+    queue.push(&graph.at(dependencyPath));
 
-        PathSet closure;
-        store->computeFSClosure({packagePath}, closure, false, false);
+    while (!queue.empty()) {
+      auto& node = *queue.top();
+      queue.pop();
 
-        if (!closure.count(dependencyPath)) {
-            printError("'%s' does not depend on '%s'", package->what(), dependency->what());
-            return;
+      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);
+          }
         }
+      }
+    }
 
-        stopProgressBar(); // FIXME
+    /* 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 string&, const string&)> printNode;
 
-        auto accessor = store->getFSAccessor();
+    const string treeConn = "╠═══";
+    const string treeLast = "╚═══";
+    const string treeLine = "║   ";
+    const string treeNull = "    ";
 
-        auto const inf = std::numeric_limits<size_t>::max();
+    struct BailOut {};
 
-        struct Node
-        {
-            Path path;
-            PathSet refs;
-            PathSet rrefs;
-            size_t dist = inf;
-            Node * prev = nullptr;
-            bool queued = false;
-            bool visited = false;
-        };
+    printNode = [&](Node& node, const string& firstPad, const string& tailPad) {
+      assert(node.dist != inf);
+      std::cout << fmt("%s%s%s%s" ANSI_NORMAL "\n", firstPad,
+                       node.visited ? "\e[38;5;244m" : "",
+                       firstPad != "" ? "=> " : "", node.path);
 
-        std::map<Path, Node> graph;
+      if (node.path == dependencyPath && !all && packagePath != dependencyPath)
+        throw BailOut();
 
-        for (auto & path : closure)
-            graph.emplace(path, Node{path, store->queryPathInfo(path)->references});
+      if (node.visited) return;
+      node.visited = true;
 
-        // Transpose the graph.
-        for (auto & node : graph)
-            for (auto & ref : node.second.refs)
-                graph[ref].rrefs.insert(node.first);
+      /* 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;
 
-        /* Run Dijkstra's shortest path algorithm to get the distance
-           of every path in the closure to 'dependency'. */
-        graph[dependencyPath].dist = 0;
+      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));
+      }
 
-        std::priority_queue<Node *> queue;
+      /* For each reference, find the files and symlinks that
+         contain the reference. */
+      std::map<std::string, Strings> hits;
 
-        queue.push(&graph.at(dependencyPath));
+      std::function<void(const Path&)> visitPath;
 
-        while (!queue.empty()) {
-            auto & node = *queue.top();
-            queue.pop();
+      visitPath = [&](const Path& p) {
+        auto st = accessor->stat(p);
 
-            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);
-                    }
-                }
+        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);
         }
 
-        /* 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 string &, const string &)> printNode;
-
-        const string treeConn = "╠═══";
-        const string treeLast = "╚═══";
-        const string treeLine = "║   ";
-        const string treeNull = "    ";
-
-        struct BailOut { };
-
-        printNode = [&](Node & node, const string & firstPad, const string & tailPad) {
-            assert(node.dist != inf);
-            std::cout << fmt("%s%s%s%s" ANSI_NORMAL "\n",
-                firstPad,
-                node.visited ? "\e[38;5;244m" : "",
-                firstPad != "" ? "=> " : "",
-                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));
+        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))));
             }
+          }
+        }
 
-            /* 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));
-            }
-        };
+        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 & ) { }
+    try {
+      printNode(graph.at(packagePath), "", "");
+    } catch (BailOut&) {
     }
+  }
 };
 
 static RegisterCommand r1(make_ref<CmdWhyDepends>());