Add disallowedReferences / disallowedRequisites

For the "stdenv accidentally referring to bootstrap-tools", it seems
easier to specify the path that we don't want to depend on, e.g.

  disallowedRequisites = [ bootstrapTools ];

src/libstore/build.cc

@@ -2318,33 +2318,36 @@ void DerivationGoal::registerOutputs()
                 debug(format("referenced input: ‘%1%’") % *i);
         }
 
-        /* If the derivation specifies an `allowedReferences'
+        /* Enforce `allowedReferences' and friends. */
-           attribute (containing a list of paths that the output may
+        auto checkRefs = [&](const string & attrName, bool allowed, bool recursive) {
-           refer to), check that all references are in that list.  !!!
+            if (drv.env.find(attrName) == drv.env.end()) return;
-           allowedReferences should really be per-output. */
-        if (drv.env.find("allowedReferences") != drv.env.end()) {
-            PathSet allowed = parseReferenceSpecifiers(drv, get(drv.env, "allowedReferences"));
-            foreach (PathSet::iterator, i, references)
-                if (allowed.find(*i) == allowed.end())
-                    throw BuildError(format("output (‘%1%’) is not allowed to refer to path ‘%2%’") % actualPath % *i);
-        }
 
-        /* If the derivation specifies an `allowedRequisites'
+            PathSet spec = parseReferenceSpecifiers(drv, get(drv.env, attrName));
-           attribute (containing a list of paths that the output may
+
-           refer to), check that all requisites are in that list.  !!!
+            PathSet used;
-           allowedRequisites should really be per-output. */
+            if (recursive) {
-        if (drv.env.find("allowedRequisites") != drv.env.end()) {
-            PathSet allowed = parseReferenceSpecifiers(drv, get(drv.env, "allowedRequisites"));
-            PathSet requisites;
                 /* Our requisites are the union of the closures of our references. */
-            foreach (PathSet::iterator, i, references)
+                for (auto & i : references)
                     /* Don't call computeFSClosure on ourselves. */
-                if (actualPath != *i)
+                    if (actualPath != i)
-                    computeFSClosure(worker.store, *i, requisites);
+                        computeFSClosure(worker.store, i, used);
-            foreach (PathSet::iterator, i, requisites)
+            } else
-                if (allowed.find(*i) == allowed.end())
+                used = references;
-                    throw BuildError(format("output (‘%1%’) is not allowed to refer to requisite path ‘%2%’") % actualPath % *i);
+
+            for (auto & i : used)
+                if (allowed) {
+                    if (spec.find(i) == spec.end())
+                        throw BuildError(format("output (‘%1%’) is not allowed to refer to path ‘%2%’") % actualPath % i);
+                } else {
+                    if (spec.find(i) != spec.end())
+                        throw BuildError(format("output (‘%1%’) is not allowed to refer to path ‘%2%’") % actualPath % i);
                 }
+        };
+
+        checkRefs("allowedReferences", true, false);
+        checkRefs("allowedRequisites", true, true);
+        checkRefs("disallowedReferences", false, false);
+        checkRefs("disallowedRequisites", false, true);
 
         worker.store.optimisePath(path); // FIXME: combine with scanForReferences()
 

tests/check-refs.nix

@@ -55,4 +55,16 @@ rec {
     inherit dep;
   };
 
+  test9 = makeTest 9 {
+    builder = builtins.toFile "builder.sh" "mkdir $out; ln -s $dep $out/link";
+    inherit dep;
+    disallowedReferences = [dep];
+  };
+
+  test10 = makeTest 10 {
+    builder = builtins.toFile "builder.sh" "mkdir $out; echo $test5; ln -s $dep $out/link";
+    inherit dep test5;
+    disallowedReferences = [test5];
+  };
+
 }

tests/check-refs.sh

@@ -32,3 +32,9 @@ nix-build -o $RESULT check-refs.nix -A test7
 
 # test8 should fail (toFile depending on derivation output).
 (! nix-build -o $RESULT check-refs.nix -A test8)
+
+# test9 should fail (disallowed reference).
+(! nix-build -o $RESULT check-refs.nix -A test9)
+
+# test10 should succeed (no disallowed references).
+nix-build -o $RESULT check-refs.nix -A test10

tests/check-reqs.nix

@@ -40,4 +40,18 @@ rec {
   test3 = makeTest 3 [ dep1 deps ];
   test4 = makeTest 4 [ deps ];
   test5 = makeTest 5 [];
+
+  test6 = mkDerivation {
+    name = "check-reqs";
+    inherit deps;
+    builder = builtins.toFile "builder.sh" "mkdir $out; ln -s $deps $out/depdir1";
+    disallowedRequisites = [dep1];
+  };
+
+  test7 = mkDerivation {
+    name = "check-reqs";
+    inherit deps;
+    builder = builtins.toFile "builder.sh" "mkdir $out; ln -s $deps $out/depdir1";
+    disallowedRequisites = [test1];
+  };
 }

tests/check-reqs.sh

@@ -2,11 +2,12 @@ source common.sh
 
 RESULT=$TEST_ROOT/result
 
-# test1 should succeed.
 nix-build -o $RESULT check-reqs.nix -A test1
 
-# test{2,3,4,5} should fail.
 (! nix-build -o $RESULT check-reqs.nix -A test2)
 (! nix-build -o $RESULT check-reqs.nix -A test3)
 (! nix-build -o $RESULT check-reqs.nix -A test4)
 (! nix-build -o $RESULT check-reqs.nix -A test5)
+(! nix-build -o $RESULT check-reqs.nix -A test6)
+
+nix-build -o $RESULT check-reqs.nix -A test7