Fix handlind of concept-id which appear as an atomic constraint

Author: cor3ntin

clang/include/clang/AST/ASTConcept.h

@@ -32,6 +32,14 @@ class Expr;
 class NamedDecl;
 struct PrintingPolicy;
 
+/// Pairs of unsatisfied atomic constraint expressions along with the
+/// substituted constraint expr, if the template arguments could be
+/// substituted into them, or a diagnostic if substitution resulted in
+/// an invalid expression.
+using UnsatisfiedConstraintRecord =
+    llvm::PointerUnion<const Expr *, const ConceptReference *,
+                       std::pair<SourceLocation, StringRef> *>;
+
 /// The result of a constraint satisfaction check, containing the necessary
 /// information to diagnose an unsatisfied constraint.
 class ConstraintSatisfaction : public llvm::FoldingSetNode {
@@ -50,15 +58,14 @@ class ConstraintSatisfaction : public llvm::FoldingSetNode {
       : ConstraintOwner(ConstraintOwner), TemplateArgs(TemplateArgs) {}
 
   using SubstitutionDiagnostic = std::pair<SourceLocation, StringRef>;
-  using Detail = llvm::PointerUnion<const Expr *, SubstitutionDiagnostic *>;
 
   bool IsSatisfied = false;
   bool ContainsErrors = false;
 
   /// \brief The substituted constraint expr, if the template arguments could be
   /// substituted into them, or a diagnostic if substitution resulted in an
   /// invalid expression.
-  llvm::SmallVector<Detail, 4> Details;
+  llvm::SmallVector<UnsatisfiedConstraintRecord, 4> Details;
 
   void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &C) {
     Profile(ID, C, ConstraintOwner, TemplateArgs);
@@ -76,13 +83,6 @@ class ConstraintSatisfaction : public llvm::FoldingSetNode {
   }
 };
 
-/// Pairs of unsatisfied atomic constraint expressions along with the
-/// substituted constraint expr, if the template arguments could be
-/// substituted into them, or a diagnostic if substitution resulted in
-/// an invalid expression.
-using UnsatisfiedConstraintRecord =
-    llvm::PointerUnion<const Expr *, std::pair<SourceLocation, StringRef> *>;
-
 /// \brief The result of a constraint satisfaction check, containing the
 /// necessary information to diagnose an unsatisfied constraint.
 ///
@@ -102,6 +102,10 @@ struct ASTConstraintSatisfaction final :
     return getTrailingObjects() + NumRecords;
   }
 
+  ArrayRef<UnsatisfiedConstraintRecord> records() const {
+    return {begin(), end()};
+  }
+
   ASTConstraintSatisfaction(const ASTContext &C,
                             const ConstraintSatisfaction &Satisfaction);
   ASTConstraintSatisfaction(const ASTContext &C,
@@ -287,6 +291,11 @@ class TypeConstraint {
   }
 };
 
+/// Insertion operator for diagnostics.  This allows sending TemplateName's
+/// into a diagnostic with <<.
+const StreamingDiagnostic &operator<<(const StreamingDiagnostic &DB,
+                                      const ConceptReference *C);
+
 } // clang
 
 #endif // LLVM_CLANG_AST_ASTCONCEPT_H

clang/lib/AST/ASTConcept.cpp

@@ -27,6 +27,9 @@ CreateUnsatisfiedConstraintRecord(const ASTContext &C,
     new (TrailingObject) UnsatisfiedConstraintRecord(nullptr);
   else if (const auto *E = llvm::dyn_cast<const Expr *>(Detail))
     new (TrailingObject) UnsatisfiedConstraintRecord(E);
+  else if (const auto *Concept =
+               llvm::dyn_cast<const ConceptReference *>(Detail))
+    new (TrailingObject) UnsatisfiedConstraintRecord(Concept);
   else {
     auto &SubstitutionDiagnostic =
         *cast<std::pair<SourceLocation, StringRef> *>(Detail);
@@ -112,6 +115,19 @@ void ConceptReference::print(llvm::raw_ostream &OS,
   }
 }
 
+const StreamingDiagnostic &clang::operator<<(const StreamingDiagnostic &DB,
+                                             const ConceptReference *C) {
+  std::string NameStr;
+  llvm::raw_string_ostream OS(NameStr);
+  LangOptions LO;
+  LO.CPlusPlus = true;
+  LO.Bool = true;
+  OS << '\'';
+  C->print(OS, PrintingPolicy(LO));
+  OS << '\'';
+  return DB << NameStr;
+}
+
 concepts::ExprRequirement::ExprRequirement(
     Expr *E, bool IsSimple, SourceLocation NoexceptLoc,
     ReturnTypeRequirement Req, SatisfactionStatus Status,