buildenv: Eliminate global variables, other cleanup

2 files changed, 76 insertions, 65 deletions

diff --git a/src/libstore/builtins/buildenv.cc b/src/libstore/builtins/buildenv.cc
index 096593886..c1c85d0bf 100644
--- a/src/libstore/builtins/buildenv.cc
+++ b/src/libstore/builtins/buildenv.cc
@@ -1,4 +1,4 @@
-#include "builtins.hh"
+#include "buildenv.hh"
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -7,16 +7,14 @@
 
 namespace nix {
 
-typedef std::map<Path,int> Priorities;
-
-// FIXME: change into local variables.
-
-static Priorities priorities;
-
-static unsigned long symlinks;
+struct State
+{
+    std::map<Path, int> priorities;
+    unsigned long symlinks = 0;
+};
 
 /* For each activated package, create symlinks */
-static void createLinks(const Path & srcDir, const Path & dstDir, int priority)
+static void createLinks(State & state, const Path & srcDir, const Path & dstDir, int priority)
 {
     DirEntries srcFiles;
 
@@ -67,7 +65,7 @@ static void createLinks(const Path & srcDir, const Path & dstDir, int priority)
             auto res = lstat(dstFile.c_str(), &dstSt);
             if (res == 0) {
                 if (S_ISDIR(dstSt.st_mode)) {
-                    createLinks(srcFile, dstFile, priority);
+                    createLinks(state, srcFile, dstFile, priority);
                     continue;
                 } else if (S_ISLNK(dstSt.st_mode)) {
                     auto target = canonPath(dstFile, true);
@@ -77,8 +75,8 @@ static void createLinks(const Path & srcDir, const Path & dstDir, int priority)
                         throw SysError(format("unlinking '%1%'") % dstFile);
                     if (mkdir(dstFile.c_str(), 0755) == -1)
                         throw SysError(format("creating directory '%1%'"));
-                    createLinks(target, dstFile, priorities[dstFile]);
-                    createLinks(srcFile, dstFile, priority);
+                    createLinks(state, target, dstFile, state.priorities[dstFile]);
+                    createLinks(state, srcFile, dstFile, priority);
                     continue;
                 }
             } else if (errno != ENOENT)
@@ -90,7 +88,7 @@ static void createLinks(const Path & srcDir, const Path & dstDir, int priority)
             auto res = lstat(dstFile.c_str(), &dstSt);
             if (res == 0) {
                 if (S_ISLNK(dstSt.st_mode)) {
-                    auto prevPriority = priorities[dstFile];
+                    auto prevPriority = state.priorities[dstFile];
                     if (prevPriority == priority)
                         throw Error(
                                 "packages '%1%' and '%2%' have the same priority %3%; "
@@ -109,41 +107,57 @@ static void createLinks(const Path & srcDir, const Path & dstDir, int priority)
         }
 
         createSymlink(srcFile, dstFile);
-        priorities[dstFile] = priority;
-        symlinks++;
+        state.priorities[dstFile] = priority;
+        state.symlinks++;
     }
 }
 
-typedef std::set<Path> FileProp;
+void buildProfile(const Path & out, Packages && pkgs)
+{
+    State state;
 
-static FileProp done;
-static FileProp postponed = FileProp{};
+    std::set<Path> done, postponed;
 
-static Path out;
+    auto addPkg = [&](const Path & pkgDir, int priority) {
+        if (!done.insert(pkgDir).second) return;
+        createLinks(state, pkgDir, out, priority);
 
-static void addPkg(const Path & pkgDir, int priority)
-{
-    if (!done.insert(pkgDir).second) return;
-    createLinks(pkgDir, out, priority);
+        try {
+            for (const auto & p : tokenizeString<std::vector<string>>(
+                    readFile(pkgDir + "/nix-support/propagated-user-env-packages"), " \n"))
+                if (!done.count(p))
+                    postponed.insert(p);
+        } catch (SysError & e) {
+            if (e.errNo != ENOENT && e.errNo != ENOTDIR) throw;
+        }
+    };
 
-    try {
-        for (const auto & p : tokenizeString<std::vector<string>>(
-                readFile(pkgDir + "/nix-support/propagated-user-env-packages"), " \n"))
-            if (!done.count(p))
-                postponed.insert(p);
-    } catch (SysError & e) {
-        if (e.errNo != ENOENT && e.errNo != ENOTDIR) throw;
-    }
-}
+    /* Symlink to the packages that have been installed explicitly by the
+     * user. Process in priority order to reduce unnecessary
+     * symlink/unlink steps.
+     */
+    std::sort(pkgs.begin(), pkgs.end(), [](const Package & a, const Package & b) {
+        return a.priority < b.priority || (a.priority == b.priority && a.path < b.path);
+    });
+    for (const auto & pkg : pkgs)
+        if (pkg.active)
+            addPkg(pkg.path, pkg.priority);
 
-struct Package {
-    Path path;
-    bool active;
-    int priority;
-    Package(Path path, bool active, int priority) : path{path}, active{active}, priority{priority} {}
-};
+    /* Symlink to the packages that have been "propagated" by packages
+     * installed by the user (i.e., package X declares that it wants Y
+     * installed as well). We do these later because they have a lower
+     * priority in case of collisions.
+     */
+    auto priorityCounter = 1000;
+    while (!postponed.empty()) {
+        std::set<Path> pkgDirs;
+        postponed.swap(pkgDirs);
+        for (const auto & pkgDir : pkgDirs)
+            addPkg(pkgDir, priorityCounter++);
+    }
 
-typedef std::vector<Package> Packages;
+    printError("created %d symlinks in user environment", state.symlinks);
+}
 
 void builtinBuildenv(const BasicDerivation & drv)
 {
@@ -153,7 +167,7 @@ void builtinBuildenv(const BasicDerivation & drv)
         return i->second;
     };
 
-    out = getAttr("out");
+    Path out = getAttr("out");
     createDirs(out);
 
     /* Convert the stuff we get from the environment back into a
@@ -171,31 +185,7 @@ void builtinBuildenv(const BasicDerivation & drv)
         }
     }
 
-    /* Symlink to the packages that have been installed explicitly by the
-     * user. Process in priority order to reduce unnecessary
-     * symlink/unlink steps.
-     */
-    std::sort(pkgs.begin(), pkgs.end(), [](const Package & a, const Package & b) {
-        return a.priority < b.priority || (a.priority == b.priority && a.path < b.path);
-    });
-    for (const auto & pkg : pkgs)
-        if (pkg.active)
-            addPkg(pkg.path, pkg.priority);
-
-    /* Symlink to the packages that have been "propagated" by packages
-     * installed by the user (i.e., package X declares that it wants Y
-     * installed as well). We do these later because they have a lower
-     * priority in case of collisions.
-     */
-    auto priorityCounter = 1000;
-    while (!postponed.empty()) {
-        auto pkgDirs = postponed;
-        postponed = FileProp{};
-        for (const auto & pkgDir : pkgDirs)
-            addPkg(pkgDir, priorityCounter++);
-    }
-
-    printError("created %d symlinks in user environment", symlinks);
+    buildProfile(out, std::move(pkgs));
 
     createSymlink(getAttr("manifest"), out + "/manifest.nix");
 }
diff --git a/src/libstore/builtins/buildenv.hh b/src/libstore/builtins/buildenv.hh
new file mode 100644
index 000000000..0a37459b0
--- /dev/null
+++ b/src/libstore/builtins/buildenv.hh
@@ -0,0 +1,21 @@
+#pragma once
+
+#include "derivations.hh"
+#include "store-api.hh"
+
+namespace nix {
+
+struct Package {
+    Path path;
+    bool active;
+    int priority;
+    Package(Path path, bool active, int priority) : path{path}, active{active}, priority{priority} {}
+};
+
+typedef std::vector<Package> Packages;
+
+void buildProfile(const Path & out, Packages && pkgs);
+
+void builtinBuildenv(const BasicDerivation & drv);
+
+}