ASP-based solver: account for deprecated versions (#23491)

fixes #22351

The ASP-based solver now accounts for the presence
in the DAG of deprecated versions and tries to minimize
their number at highest priority.

lib/spack/spack/solver/asp.py

@@ -411,6 +411,7 @@ def __init__(self):
         self.gen = None  # set by setup()
         self.possible_versions = {}
         self.versions_in_package_py = {}
+        self.deprecated_versions = {}
         self.versions_from_externals = {}
         self.possible_virtuals = None
         self.possible_compilers = []
@@ -481,6 +482,11 @@ def pkg_version_rules(self, pkg):
         for i, v in enumerate(most_to_least_preferred):
             self.gen.fact(fn.version_declared(pkg.name, v, i))
 
+        # Declare deprecated versions for this package, if any
+        deprecated = self.deprecated_versions[pkg.name]
+        for v in sorted(deprecated):
+            self.gen.fact(fn.deprecated_version(pkg.name, v))
+
     def spec_versions(self, spec):
         """Return list of clauses expressing spec's version constraints."""
         spec = specify(spec)
@@ -1020,12 +1026,16 @@ def build_version_dict(self, possible_pkgs, specs):
         self.possible_versions = collections.defaultdict(set)
         self.versions_in_package_py = collections.defaultdict(set)
         self.versions_from_externals = collections.defaultdict(set)
+        self.deprecated_versions = collections.defaultdict(set)
 
         for pkg_name in possible_pkgs:
             pkg = spack.repo.get(pkg_name)
-            for v in pkg.versions:
+            for v, version_info in pkg.versions.items():
                 self.versions_in_package_py[pkg_name].add(v)
                 self.possible_versions[pkg_name].add(v)
+                deprecated = version_info.get('deprecated', False)
+                if deprecated:
+                    self.deprecated_versions[pkg_name].add(v)
 
         for spec in specs:
             for dep in spec.traverse():
@@ -1553,6 +1563,10 @@ def reorder_flags(self):
             check_same_flags(spec.compiler_flags, flags)
             spec.compiler_flags.update(flags)
 
+    def deprecated(self, pkg, version):
+        msg = 'using "{0}@{1}" which is a deprecated version'
+        tty.warn(msg.format(pkg, version))
+
     def build_specs(self, function_tuples):
         # Functions don't seem to be in particular order in output.  Sort
         # them here so that directives that build objects (like node and

lib/spack/spack/solver/concretize.lp

@@ -19,6 +19,9 @@ version_declared(Package, Version) :- version_declared(Package, Version, _).
 1 { version(Package, Version) : version_declared(Package, Version) } 1
  :- node(Package).
 
+% If we select a deprecated version, mark the package as deprecated
+deprecated(Package, Version) :- version(Package, Version), deprecated_version(Package, Version).
+
 possible_version_weight(Package, Weight)
  :- version(Package, Version), version_declared(Package, Version, Weight),
     not preferred_version_declared(Package, Version, _).
@@ -37,6 +40,7 @@ version_satisfies(Package, Constraint)
 
 #defined preferred_version_declared/3.
 #defined version_satisfies/3.
+#defined deprecated_version/2.
 
 %-----------------------------------------------------------------------------
 % Spec conditions and imposed constraints
@@ -696,6 +700,11 @@ no_flags(Package, FlagType)
 %   2. a `#minimize{ 0@2 : #true }.` statement that ensures the criterion
 %      is displayed (clingo doesn't display sums over empty sets by default)
 
+% Minimize the number of deprecated versions being used
+opt_criterion(16, "deprecated versions used").
+#minimize{ 0@16 : #true }.
+#minimize{ 1@16,Package : deprecated(Package, _)}.
+
 % The highest priority is to minimize the:
 % 1. Version weight
 % 2. Number of variants with a non default value, if not set

lib/spack/spack/solver/display.lp

@@ -28,3 +28,6 @@
 
 % names of optimization criteria
 #show opt_criterion/2.
+
+% deprecated packages
+#show deprecated/2.

lib/spack/spack/test/concretize.py

@@ -1228,3 +1228,19 @@ def test_multivalued_variants_from_cli(self, spec_str, expected_dict):
 
         for constraint, value in expected_dict.items():
             assert s.satisfies(constraint) == value
+
+    @pytest.mark.regression('22351')
+    @pytest.mark.parametrize('spec_str,expected', [
+        # Version 1.1.0 is deprecated and should not be selected, unless we
+        # explicitly asked for that
+        ('deprecated-versions', ['deprecated-versions@1.0.0']),
+        ('deprecated-versions@1.1.0', ['deprecated-versions@1.1.0']),
+    ])
+    def test_deprecated_versions_not_selected(self, spec_str, expected):
+        if spack.config.get('config:concretizer') == 'original':
+            pytest.xfail('Known failure of the original concretizer')
+
+        s = Spec(spec_str).concretized()
+
+        for abstract_spec in expected:
+            assert abstract_spec in s

var/spack/repos/builtin.mock/packages/deprecated-versions/package.py

@@ -0,0 +1,12 @@
+# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+class DeprecatedVersions(Package):
+    """Package with the most recent version deprecated"""
+
+    homepage = "http://www.example.com"
+    url = "http://www.example.com/c-1.0.tar.gz"
+
+    version('1.1.0', '0123456789abcdef0123456789abcdef', deprecated=True)
+    version('1.0.0', '0123456789abcdef0123456789abcdef')