Relax architecture compatibility check (#15972)

* Relax architecture compatibility check
* Add test coverage for the spack.abi module

lib/spack/spack/abi.py

@@ -18,10 +18,13 @@ class ABI(object):
     """This class provides methods to test ABI compatibility between specs.
        The current implementation is rather rough and could be improved."""
 
-    def architecture_compatible(self, parent, child):
-        """Return true if parent and child have ABI compatible targets."""
-        return not parent.architecture or not child.architecture or \
-            parent.architecture == child.architecture
+    def architecture_compatible(self, target, constraint):
+        """Return true if architecture of target spec is ABI compatible
+           to the architecture of constraint spec. If either the target
+           or constraint specs have no architecture, target is also defined
+           as architecture ABI compatible to constraint."""
+        return not target.architecture or not constraint.architecture or \
+            target.architecture.satisfies(constraint.architecture)
 
     @memoized
     def _gcc_get_libstdcxx_version(self, version):
@@ -107,8 +110,8 @@ def compiler_compatible(self, parent, child, **kwargs):
                     return True
         return False
 
-    def compatible(self, parent, child, **kwargs):
-        """Returns true iff a parent and child spec are ABI compatible"""
+    def compatible(self, target, constraint, **kwargs):
+        """Returns true if target spec is ABI compatible to constraint spec"""
         loosematch = kwargs.get('loose', False)
-        return self.architecture_compatible(parent, child) and \
-            self.compiler_compatible(parent, child, loose=loosematch)
+        return self.architecture_compatible(target, constraint) and \
+            self.compiler_compatible(target, constraint, loose=loosematch)

lib/spack/spack/test/abi.py

@@ -0,0 +1,66 @@
+# Copyright 2013-2020 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)
+""" Test ABI compatibility helpers"""
+
+import pytest
+
+from spack.abi import ABI
+from spack.spec import Spec
+
+
+@pytest.mark.parametrize(
+    'target,constraint,expected',
+    [
+        ('foo', 'bar', True),
+        ('platform=linux', 'foo', True),
+        ('foo', 'arch=linux-fedora31-x86_64', True),
+        ('arch=linux-fedora31-skylake', 'arch=linux-fedora31-skylake', True),
+        ('arch=linux-fedora31-skylake', 'arch=linux-fedora31-x86_64', False),
+        ('platform=linux os=fedora31', 'arch=linux-fedora31-x86_64', True),
+        ('platform=linux', 'arch=linux-fedora31-x86_64', True),
+        ('platform=linux os=fedora31', 'platform=linux', True),
+        ('platform=darwin', 'arch=linux-fedora31-x86_64', False),
+        ('os=fedora31', 'platform=linux', False),  # TODO should be true ?
+    ])
+def test_architecture_compatibility(target, constraint, expected):
+    assert ABI().architecture_compatible(Spec(target),
+                                         Spec(constraint)) == expected
+
+
+@pytest.mark.parametrize(
+    'target,constraint,loose,expected',
+    [
+        ('foo', 'bar', False, True),
+        ('%gcc', 'foo', False, True),
+        ('foo', '%gcc', False, True),
+        ('%gcc', '%gcc', False, True),
+        ('%gcc', '%intel', False, False),
+        ('%gcc', '%clang', False, False),
+        ('%gcc@9.1', '%gcc@9.2', False, False),  # TODO should be true ?
+        ('%gcc@9.2.1', '%gcc@9.2.2', False, False),  # TODO should be true ?
+        ('%gcc@4.9', '%gcc@9.2', False, False),
+        ('%clang@5', '%clang@6', False, False),
+        ('%gcc@9.1', '%gcc@9.2', True, True),
+        ('%gcc@9.2.1', '%gcc@9.2.2', True, True),
+        ('%gcc@4.9', '%gcc@9.2', True, True),
+        ('%clang@5', '%clang@6', True, True),
+    ])
+def test_compiler_compatibility(target, constraint, loose, expected):
+    assert ABI().compiler_compatible(Spec(target),
+                                     Spec(constraint),
+                                     loose=loose) == expected
+
+
+@pytest.mark.parametrize('target,constraint,loose,expected', [
+    ('foo', 'bar', False, True),
+    ('%gcc', 'platform=linux', False, True),
+    ('%gcc@9.2.1', '%gcc@8.3.1 platform=linux', False, False),
+    ('%gcc@9.2.1', '%gcc@8.3.1 platform=linux', True, True),
+    ('%gcc@9.2.1 arch=linux-fedora31-skylake', '%gcc@9.2.1 platform=linux',
+     False, True),
+])
+def test_compatibility(target, constraint, loose, expected):
+    assert ABI().compatible(Spec(target), Spec(constraint),
+                            loose=loose) == expected