From 59acfe4f0b78ee9fa65afda0f89cff76b330fa27 Mon Sep 17 00:00:00 2001
From: Gregory Becker <becker33@llnl.gov>
Date: Mon, 12 Dec 2022 15:51:38 -0800
Subject: [PATCH] solver: treat literals as conditions

---
 lib/spack/spack/solver/asp.py        | 24 +++++++++++++++++-------
 lib/spack/spack/solver/concretize.lp | 16 +++-------------
 2 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/lib/spack/spack/solver/asp.py b/lib/spack/spack/solver/asp.py
index 66d790c7dd2..7a47aace422 100644
--- a/lib/spack/spack/solver/asp.py
+++ b/lib/spack/spack/solver/asp.py
@@ -2300,17 +2300,26 @@ def setup(self, driver, specs, reuse=None):
         self.define_target_constraints()
 
     def literal_specs(self, specs):
-        for idx, spec in enumerate(specs):
+        for spec in specs:
             self.gen.h2("Spec: %s" % str(spec))
-            self.gen.fact(fn.literal(idx))
 
-            self.gen.fact(fn.literal(idx, "virtual_root" if spec.virtual else "root", spec.name))
+            # cannot use self.condition because it requires condition requirements
+            condition_id = next(self._condition_id_counter)
+            self.gen.fact(fn.condition(condition_id, "%s is provided as input spec" % spec))
+            self.gen.fact(fn.literal(condition_id))
+
+            self.gen.fact(fn.condition_requirement(condition_id, "literal_solved", condition_id))
+
+            self.gen.fact(fn.imposed_constraint(
+                condition_id, "virtual_root" if spec.virtual else "root", spec.name
+            ))
+
             for clause in self.spec_clauses(spec):
-                self.gen.fact(fn.literal(idx, *clause.args))
+                self.gen.fact(fn.imposed_constraint(condition_id, *clause.args))
                 if clause.args[0] == "variant_set":
-                    self.gen.fact(
-                        fn.literal(idx, "variant_default_value_from_cli", *clause.args[1:])
-                    )
+                    self.gen.fact(fn.imposed_constraint(
+                        condition_id, "variant_default_value_from_cli", *clause.args[1:]
+                    ))
 
         if self.concretize_everything:
             self.gen.fact(fn.concretize_everything())
@@ -2404,6 +2413,7 @@ class SpecBuilder(object):
                 r"^virtual_node$",
                 r"^virtual_root$",
                 r"^.*holds?$",
+                r"^literal.*$",
             ]
         )
     )
diff --git a/lib/spack/spack/solver/concretize.lp b/lib/spack/spack/solver/concretize.lp
index 98327dcc501..d2f2cdb6fb1 100644
--- a/lib/spack/spack/solver/concretize.lp
+++ b/lib/spack/spack/solver/concretize.lp
@@ -12,8 +12,8 @@
 %-----------------------------------------------------------------------------
 
 % Give clingo the choice to solve an input spec or not
-{ literal_solved(ID) } :- literal(ID).
-literal_not_solved(ID) :- not literal_solved(ID), literal(ID).
+{ attr("literal_solved", ID) } :- literal(ID).
+literal_not_solved(ID) :- not attr("literal_solved", ID), literal(ID).
 
 % If concretize_everything() is a fact, then we cannot have unsolved specs
 :- literal_not_solved(ID), concretize_everything.
@@ -21,24 +21,14 @@ literal_not_solved(ID) :- not literal_solved(ID), literal(ID).
 % Make a problem with "zero literals solved" unsat. This is to trigger
 % looking for solutions to the ASP problem with "errors", which results
 % in better reporting for users. See #30669 for details.
-1 { literal_solved(ID) : literal(ID) }.
+1 { attr("literal_solved", ID) : literal(ID) }.
 
 opt_criterion(300, "number of input specs not concretized").
 #minimize{ 0@300: #true }.
 #minimize { 1@300,ID : literal_not_solved(ID) }.
 
-% Map constraint on the literal ID to the correct PSID
-attr(Name, A1)             :- literal(LiteralID, Name, A1), literal_solved(LiteralID).
-attr(Name, A1, A2)         :- literal(LiteralID, Name, A1, A2), literal_solved(LiteralID).
-attr(Name, A1, A2, A3)     :- literal(LiteralID, Name, A1, A2, A3), literal_solved(LiteralID).
-attr(Name, A1, A2, A3, A4) :- literal(LiteralID, Name, A1, A2, A3, A4), literal_solved(LiteralID).
-
 #defined concretize_everything/0.
 #defined literal/1.
-#defined literal/3.
-#defined literal/4.
-#defined literal/5.
-#defined literal/6.
 
 % Attributes for node packages which must have a single value
 attr_single_value("version").