[NFCI] Propagate MLTAL through more concepts in prep of deferred inst.

Erich Keane · Erich Keane · commit b25902736c2e · 2022-07-29T05:54:04.000-07:00
In preperation of the deferred instantation progress, this patch
propagates the multi-level template argument lists further through the
API to reduce the size of that patch.
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -7153,7 +7153,7 @@ class Sema final {
   /// false otherwise.
   bool CheckConstraintSatisfaction(
       const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
-      ArrayRef<TemplateArgument> TemplateArgs,
+      const MultiLevelTemplateArgumentList &TemplateArgLists,
       SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction);
 
   /// \brief Check whether the given non-dependent constraint expression is
@@ -7189,9 +7189,10 @@ class Sema final {
   ///
   /// \returns true if the constrains are not satisfied or could not be checked
   /// for satisfaction, false if the constraints are satisfied.
-  bool EnsureTemplateArgumentListConstraints(TemplateDecl *Template,
-                                       ArrayRef<TemplateArgument> TemplateArgs,
-                                             SourceRange TemplateIDRange);
+  bool EnsureTemplateArgumentListConstraints(
+      TemplateDecl *Template,
+      const MultiLevelTemplateArgumentList &TemplateArgs,
+      SourceRange TemplateIDRange);
 
   /// \brief Emit diagnostics explaining why a constraint expression was deemed
   /// unsatisfied.
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
@@ -199,9 +199,9 @@ calculateConstraintSatisfaction(Sema &S, const Expr *ConstraintExpr,
 }
 
 static bool calculateConstraintSatisfaction(
-    Sema &S, const NamedDecl *Template, ArrayRef<TemplateArgument> TemplateArgs,
-    SourceLocation TemplateNameLoc, MultiLevelTemplateArgumentList &MLTAL,
-    const Expr *ConstraintExpr, ConstraintSatisfaction &Satisfaction) {
+    Sema &S, const NamedDecl *Template, SourceLocation TemplateNameLoc,
+    const MultiLevelTemplateArgumentList &MLTAL, const Expr *ConstraintExpr,
+    ConstraintSatisfaction &Satisfaction) {
   return calculateConstraintSatisfaction(
       S, ConstraintExpr, Satisfaction, [&](const Expr *AtomicExpr) {
         EnterExpressionEvaluationContext ConstantEvaluated(
@@ -268,36 +268,35 @@ static bool calculateConstraintSatisfaction(
       });
 }
 
-static bool CheckConstraintSatisfaction(Sema &S, const NamedDecl *Template,
-                                        ArrayRef<const Expr *> ConstraintExprs,
-                                        ArrayRef<TemplateArgument> TemplateArgs,
-                                        SourceRange TemplateIDRange,
-                                        ConstraintSatisfaction &Satisfaction) {
+static bool CheckConstraintSatisfaction(
+    Sema &S, const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
+    const MultiLevelTemplateArgumentList &TemplateArgsLists,
+    SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction) {
   if (ConstraintExprs.empty()) {
     Satisfaction.IsSatisfied = true;
     return false;
   }
 
-  for (auto& Arg : TemplateArgs)
-    if (Arg.isInstantiationDependent()) {
-      // No need to check satisfaction for dependent constraint expressions.
-      Satisfaction.IsSatisfied = true;
-      return false;
-    }
+  if (TemplateArgsLists.isAnyArgInstantiationDependent()) {
+    // No need to check satisfaction for dependent constraint expressions.
+    Satisfaction.IsSatisfied = true;
+    return false;
+  }
 
+  ArrayRef<TemplateArgument> TemplateArgs =
+      TemplateArgsLists.getNumSubstitutedLevels() > 0
+          ? TemplateArgsLists.getOutermost()
+          : ArrayRef<TemplateArgument> {};
   Sema::InstantiatingTemplate Inst(S, TemplateIDRange.getBegin(),
       Sema::InstantiatingTemplate::ConstraintsCheck{},
       const_cast<NamedDecl *>(Template), TemplateArgs, TemplateIDRange);
   if (Inst.isInvalid())
     return true;
 
-  MultiLevelTemplateArgumentList MLTAL;
-  MLTAL.addOuterTemplateArguments(TemplateArgs);
-
   for (const Expr *ConstraintExpr : ConstraintExprs) {
-    if (calculateConstraintSatisfaction(S, Template, TemplateArgs,
-                                        TemplateIDRange.getBegin(), MLTAL,
-                                        ConstraintExpr, Satisfaction))
+    if (calculateConstraintSatisfaction(S, Template, TemplateIDRange.getBegin(),
+                                        TemplateArgsLists, ConstraintExpr,
+                                        Satisfaction))
       return true;
     if (!Satisfaction.IsSatisfied)
       // [temp.constr.op] p2
@@ -311,28 +310,37 @@ static bool CheckConstraintSatisfaction(Sema &S, const NamedDecl *Template,
 
 bool Sema::CheckConstraintSatisfaction(
     const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
-    ArrayRef<TemplateArgument> TemplateArgs, SourceRange TemplateIDRange,
-    ConstraintSatisfaction &OutSatisfaction) {
+    const MultiLevelTemplateArgumentList &TemplateArgsLists,
+    SourceRange TemplateIDRange, ConstraintSatisfaction &OutSatisfaction) {
   if (ConstraintExprs.empty()) {
     OutSatisfaction.IsSatisfied = true;
     return false;
   }
   if (!Template) {
     return ::CheckConstraintSatisfaction(*this, nullptr, ConstraintExprs,
-                                         TemplateArgs, TemplateIDRange,
+                                         TemplateArgsLists, TemplateIDRange,
                                          OutSatisfaction);
   }
+
+  // A list of the template argument list flattened in a predictible manner for
+  // the purposes of caching. The ConstraintSatisfaction type is in AST so it
+  // has no access to the MultiLevelTemplateArgumentList, so this has to happen
+  // here.
+  llvm::SmallVector<TemplateArgument, 4> FlattenedArgs;
+  for (ArrayRef<TemplateArgument> List : TemplateArgsLists)
+    FlattenedArgs.insert(FlattenedArgs.end(), List.begin(), List.end());
+
   llvm::FoldingSetNodeID ID;
-  ConstraintSatisfaction::Profile(ID, Context, Template, TemplateArgs);
+  ConstraintSatisfaction::Profile(ID, Context, Template, FlattenedArgs);
   void *InsertPos;
   if (auto *Cached = SatisfactionCache.FindNodeOrInsertPos(ID, InsertPos)) {
     OutSatisfaction = *Cached;
     return false;
   }
   auto Satisfaction =
-      std::make_unique<ConstraintSatisfaction>(Template, TemplateArgs);
+      std::make_unique<ConstraintSatisfaction>(Template, FlattenedArgs);
   if (::CheckConstraintSatisfaction(*this, Template, ConstraintExprs,
-                                    TemplateArgs, TemplateIDRange,
+                                    TemplateArgsLists, TemplateIDRange,
                                     *Satisfaction)) {
     return true;
   }
@@ -379,20 +387,21 @@ bool Sema::CheckFunctionConstraints(const FunctionDecl *FD,
 }
 
 bool Sema::EnsureTemplateArgumentListConstraints(
-    TemplateDecl *TD, ArrayRef<TemplateArgument> TemplateArgs,
+    TemplateDecl *TD, const MultiLevelTemplateArgumentList &TemplateArgsLists,
     SourceRange TemplateIDRange) {
   ConstraintSatisfaction Satisfaction;
   llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
   TD->getAssociatedConstraints(AssociatedConstraints);
-  if (CheckConstraintSatisfaction(TD, AssociatedConstraints, TemplateArgs,
+  if (CheckConstraintSatisfaction(TD, AssociatedConstraints, TemplateArgsLists,
                                   TemplateIDRange, Satisfaction))
     return true;
 
   if (!Satisfaction.IsSatisfied) {
     SmallString<128> TemplateArgString;
     TemplateArgString = " ";
     TemplateArgString += getTemplateArgumentBindingsText(
-        TD->getTemplateParameters(), TemplateArgs.data(), TemplateArgs.size());
+        TD->getTemplateParameters(), TemplateArgsLists.getInnermost().data(),
+        TemplateArgsLists.getInnermost().size());
 
     Diag(TemplateIDRange.getBegin(),
          diag::err_template_arg_list_constraints_not_satisfied)
@@ -423,6 +432,10 @@ bool Sema::CheckInstantiatedFunctionTemplateConstraints(
   // PushDeclContext because we don't have a scope.
   Sema::ContextRAII savedContext(*this, Decl);
   LocalInstantiationScope Scope(*this);
+  MultiLevelTemplateArgumentList MLTAL;
+  // FIXME: This will be replaced with some logic to get all the template
+  // arguments when we switch to deferred template instantiation.
+  MLTAL.addOuterTemplateArguments(TemplateArgs);
 
   // If this is not an explicit specialization - we need to get the instantiated
   // version of the template arguments and add them to scope for the
@@ -446,7 +459,7 @@ bool Sema::CheckInstantiatedFunctionTemplateConstraints(
     Record = Method->getParent();
   }
   CXXThisScopeRAII ThisScope(*this, Record, ThisQuals, Record != nullptr);
-  return CheckConstraintSatisfaction(Template, TemplateAC, TemplateArgs,
+  return CheckConstraintSatisfaction(Template, TemplateAC, MLTAL,
                                      PointOfInstantiation, Satisfaction);
 }
 
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
@@ -4751,9 +4751,12 @@ Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
   bool AreArgsDependent =
       TemplateSpecializationType::anyDependentTemplateArguments(*TemplateArgs,
                                                                 Converted);
+  MultiLevelTemplateArgumentList MLTAL;
+  MLTAL.addOuterTemplateArguments(Converted);
+  LocalInstantiationScope Scope(*this);
   if (!AreArgsDependent &&
       CheckConstraintSatisfaction(
-          NamedConcept, {NamedConcept->getConstraintExpr()}, Converted,
+          NamedConcept, {NamedConcept->getConstraintExpr()}, MLTAL,
           SourceRange(SS.isSet() ? SS.getBeginLoc() : ConceptNameInfo.getLoc(),
                       TemplateArgs->getRAngleLoc()),
           Satisfaction))
@@ -5970,13 +5973,18 @@ bool Sema::CheckTemplateArgumentList(
   if (UpdateArgsWithConversions)
     TemplateArgs = std::move(NewArgs);
 
-  if (!PartialTemplateArgs &&
-      EnsureTemplateArgumentListConstraints(
-        Template, Converted, SourceRange(TemplateLoc,
-                                         TemplateArgs.getRAngleLoc()))) {
-    if (ConstraintsNotSatisfied)
-      *ConstraintsNotSatisfied = true;
-    return true;
+  if (!PartialTemplateArgs) {
+    // FIXME: This will be changed a bit once deferred concept instantiation is
+    // implemented.
+    MultiLevelTemplateArgumentList MLTAL;
+    MLTAL.addOuterTemplateArguments(Converted);
+    if (EnsureTemplateArgumentListConstraints(
+            Template, MLTAL,
+            SourceRange(TemplateLoc, TemplateArgs.getRAngleLoc()))) {
+      if (ConstraintsNotSatisfied)
+        *ConstraintsNotSatisfied = true;
+      return true;
+    }
   }
 
   return false;
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -2791,8 +2791,13 @@ CheckDeducedArgumentConstraints(Sema& S, TemplateDeclT *Template,
                                 TemplateDeductionInfo& Info) {
   llvm::SmallVector<const Expr *, 3> AssociatedConstraints;
   Template->getAssociatedConstraints(AssociatedConstraints);
+  // FIXME: This will change quite a bit once deferred concept instantiation is
+  // implemented.
+  MultiLevelTemplateArgumentList MLTAL;
+  MLTAL.addOuterTemplateArguments(DeducedArgs);
+
   if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints,
-                                    DeducedArgs, Info.getLocation(),
+                                    MLTAL, Info.getLocation(),
                                     Info.AssociatedConstraintsSatisfaction) ||
       !Info.AssociatedConstraintsSatisfaction.IsSatisfied) {
     Info.reset(TemplateArgumentList::CreateCopy(S.Context, DeducedArgs));
@@ -4572,8 +4577,10 @@ CheckDeducedPlaceholderConstraints(Sema &S, const AutoType &Type,
   if (S.CheckTemplateArgumentList(Concept, SourceLocation(), TemplateArgs,
                                   /*PartialTemplateArgs=*/false, Converted))
     return Sema::DAR_FailedAlreadyDiagnosed;
+  MultiLevelTemplateArgumentList MLTAL;
+  MLTAL.addOuterTemplateArguments(Converted);
   if (S.CheckConstraintSatisfaction(Concept, {Concept->getConstraintExpr()},
-                                    Converted, TypeLoc.getLocalSourceRange(),
+                                    MLTAL, TypeLoc.getLocalSourceRange(),
                                     Satisfaction))
     return Sema::DAR_FailedAlreadyDiagnosed;
   if (!Satisfaction.IsSatisfied) {
