Spec.satisfies accesses Spec.concrete as property (#2928)

* Spec.satisfies accesses Spec.concrete as property

Fixes #2760

When copying a spec, _concrete is always set to False for each
dependency. "Spec.satisfies" was accessing the member "_concrete"
directly instead of using the property "concrete". This means that
if you copy a spec, the dependencies will be considered equal, but
did not necessarily satisfy one another. Spec.satisfies is a
prerequisite for a package to be considered an extension; as a
consequence, an extension with run-time dependencies that were also
extensions did not activate those extensions. This updates
Spec.satisfies to avoid checking the cached member "_concrete"
directly.

* Added test to check for activation of dependency extension

* Added test to check for transitive satisfiability between a spec and its copy

4 files changed, 24 insertions, 6 deletions

diff --git a/lib/spack/spack/package.py b/lib/spack/spack/package.py
index 0841ddcd61..797ae1ff5d 100644
--- a/lib/spack/spack/package.py
+++ b/lib/spack/spack/package.py
@@ -1560,10 +1560,9 @@ class PackageBase(object):
 
         # Activate any package dependencies that are also extensions.
         if not force:
-            for spec in self.spec.traverse(root=False, deptype='run'):
-                if spec.package.extends(self.extendee_spec):
-                    if not spec.package.activated:
-                        spec.package.do_activate(force=force)
+            for spec in self.dependency_activations():
+                if not spec.package.activated:
+                    spec.package.do_activate(force=force)
 
         self.extendee_spec.package.activate(self, **self.extendee_args)
 
@@ -1571,6 +1570,10 @@ class PackageBase(object):
         tty.msg("Activated extension %s for %s" %
                 (self.spec.short_spec, self.extendee_spec.format("$_$@$+$%@")))
 
+    def dependency_activations(self):
+        return (spec for spec in self.spec.traverse(root=False, deptype='run')
+                if spec.package.extends(self.extendee_spec))
+
     def activate(self, extension, **kwargs):
         """Symlinks all files from the extension into extendee's install dir.
 
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 8f315fdabf..059653a72a 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -2011,8 +2011,8 @@ class Spec(object):
         other = self._autospec(other)
 
         # The only way to satisfy a concrete spec is to match its hash exactly.
-        if other._concrete:
-            return self._concrete and self.dag_hash() == other.dag_hash()
+        if other.concrete:
+            return self.concrete and self.dag_hash() == other.dag_hash()
 
         # A concrete provider can satisfy a virtual dependency.
         if not self.virtual and other.virtual:
diff --git a/lib/spack/spack/test/packages.py b/lib/spack/spack/test/packages.py
index 6ae8a33a24..bc1f438e44 100644
--- a/lib/spack/spack/test/packages.py
+++ b/lib/spack/spack/test/packages.py
@@ -108,6 +108,13 @@ def test_inheritance_of_diretives():
     assert 'mpi' in s
 
 
+def test_dependency_extensions():
+    s = Spec('extension2')
+    s.concretize()
+    deps = set(x.name for x in s.package.dependency_activations())
+    assert deps == set(['extension1'])
+
+
 def test_import_class_from_package(builtin_mock):
     from spack.pkg.builtin.mock.mpich import Mpich  # noqa
 
diff --git a/lib/spack/spack/test/spec_semantics.py b/lib/spack/spack/test/spec_semantics.py
index 84c8650f15..2f3b2b1b8d 100644
--- a/lib/spack/spack/test/spec_semantics.py
+++ b/lib/spack/spack/test/spec_semantics.py
@@ -287,6 +287,14 @@ class TestSpecSematics(object):
         # 'mpich' is concrete:
         check_unsatisfiable('mpich', 'mpich cppflags="-O3"', True)
 
+    def test_copy_satisfies_transitive(self):
+        spec = Spec('dttop')
+        spec.concretize()
+        copy = spec.copy()
+        for s in spec.traverse():
+            assert s.satisfies(copy[s.name])
+            assert copy[s.name].satisfies(s) 
+
     def test_unsatisfiable_compiler_flag_mismatch(self):
         # No matchi in specs
         check_unsatisfiable(