[libcxx-commits] [clang] [libcxx] [Clang][WIP] Normalize constraints before checking for satisfaction (PR #141776)

[Younan Zhang via libcxx-commits]

================
@@ -543,30 +672,330 @@ static ExprResult calculateConstraintSatisfaction(
     return ExprError();
   }
 
-  assert(EvalResult.Val.isInt() &&
-         "evaluating bool expression didn't produce int");
-  Satisfaction.IsSatisfied = EvalResult.Val.getInt().getBoolValue();
-  if (!Satisfaction.IsSatisfied)
-    Satisfaction.Details.emplace_back(SubstitutedAtomicExpr.get());
+  assert(EvalResult.Val.isInt() &&
+         "evaluating bool expression didn't produce int");
+  Satisfaction.IsSatisfied = EvalResult.Val.getInt().getBoolValue();
+  if (!Satisfaction.IsSatisfied)
+    Satisfaction.Details.emplace_back(SubstitutedAtomicExpr.get());
+
+  return SubstitutedAtomicExpr;
+}
+
+ExprResult CalculateConstraintSatisfaction::Calculate(
+    const AtomicConstraint &Constraint,
+    const MultiLevelTemplateArgumentList &MLTAL) {
+
+  unsigned Size = Satisfaction.Details.size();
+  llvm::FoldingSetNodeID ID;
+  UnsignedOrNone OuterPackSubstIndex =
+      Constraint.getPackSubstitutionIndex()
+          ? Constraint.getPackSubstitutionIndex()
+          : PackSubstitutionIndex;
+  // Constraint.getConstraintExpr()->Profile(ID, S.Context, /*Canonical=*/true,
+  //                                         /*ProfileLambdaExpr=*/true);
+  auto *Previous = Constraint.getConstraintExpr();
+  ID.AddPointer(Constraint.getConstraintExpr());
+  ID.AddInteger(OuterPackSubstIndex.toInternalRepresentation());
+  ID.AddBoolean(Constraint.hasParameterMapping());
+  HashParameterMapping(S, MLTAL, ID, OuterPackSubstIndex)
+      .VisitConstraint(Constraint);
+
+  if (auto Iter = S.ConceptIdSatisfactionCache.find(ID);
+      Iter != S.ConceptIdSatisfactionCache.end()) {
+
+    auto &Cached = Iter->second.Satisfaction;
+    Satisfaction.ContainsErrors = Cached.ContainsErrors;
+    Satisfaction.IsSatisfied = Cached.IsSatisfied;
+    Satisfaction.Details.insert(Satisfaction.Details.begin() + Size,
+                                Cached.Details.begin(), Cached.Details.end());
+    return Iter->second.SubstExpr;
+  }
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zyn0217 wrote:

I added an assert here to detect the incorrect cache values. I think it'd be better to get it back, before we can ensure the patch works on many other libraries.

https://github.com/llvm/llvm-project/pull/141776