[AST] Print ErrorType as _

include/swift/AST/PrintOptions.h

@@ -694,6 +694,13 @@ struct PrintOptions {
     return result;
   }
 
+  /// Print options suitable for debug printing.
+  static PrintOptions forDebugging() {
+    PrintOptions result;
+    result.PrintTypesForDebugging = true;
+    return result;
+  }
+
   /// Retrieve the set of options suitable for diagnostics printing.
   static PrintOptions printForDiagnostics(AccessLevel accessFilter,
                                           bool printFullConvention) {

include/swift/IDE/Utils.h

@@ -402,7 +402,8 @@ struct ResolvedRangeInfo {
                     /*Single entry*/true, /*UnhandledEffects*/{},
                     OrphanKind::None, {}, {}, {}) {}
   ResolvedRangeInfo(): ResolvedRangeInfo(ArrayRef<Token>()) {}
-  void print(llvm::raw_ostream &OS) const;
+  void print(llvm::raw_ostream &OS,
+             const PrintOptions &PO = PrintOptions()) const;
   ExitState exit() const { return ExitInfo.Exit; }
   Type getType() const { return ExitInfo.ReturnType; }
 

include/swift/Sema/ConstraintSystem.h

@@ -6223,8 +6223,7 @@ class TypeVariableBinding {
   fixForHole(ConstraintSystem &cs) const;
 
   void print(llvm::raw_ostream &Out, SourceManager *, unsigned indent) const {
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
+    PrintOptions PO = PrintOptions::forDebugging();
     Out << "type variable binding " << TypeVar->getString(PO)
         << " := " << Binding.BindingType->getString(PO);
   }

lib/AST/ASTDumper.cpp

@@ -3398,13 +3398,11 @@ class PrintExpr : public ExprVisitor<PrintExpr, void, Label>,
   /// FIXME: This should use ExprWalker to print children.
 
   void printCommon(Expr *E, const char *C, Label label) {
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
-
     printHead(C, ExprColor, label);
 
     printFlag(E->isImplicit(), "implicit", ExprModifierColor);
-    printTypeField(GetTypeOfExpr(E), Label::always("type"), PO, TypeColor);
+    printTypeField(GetTypeOfExpr(E), Label::always("type"),
+                   PrintOptions::forDebugging(), TypeColor);
 
     // If we have a source range and an ASTContext, print the source range.
     if (auto Ty = GetTypeOfExpr(E)) {
@@ -4054,10 +4052,8 @@ class PrintExpr : public ExprVisitor<PrintExpr, void, Label>,
   void visitForceTryExpr(ForceTryExpr *E, Label label) {
     printCommon(E, "force_try_expr", label);
 
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
-    printTypeField(E->getThrownError(), Label::always("thrown_error"), PO,
-                   TypeColor);
+    printTypeField(E->getThrownError(), Label::always("thrown_error"),
+                   PrintOptions::forDebugging(), TypeColor);
 
     printRec(E->getSubExpr(), Label::optional("sub_expr"));
     printFoot();
@@ -4066,10 +4062,8 @@ class PrintExpr : public ExprVisitor<PrintExpr, void, Label>,
   void visitOptionalTryExpr(OptionalTryExpr *E, Label label) {
     printCommon(E, "optional_try_expr", label);
 
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
-    printTypeField(E->getThrownError(), Label::always("thrown_error"), PO,
-                   TypeColor);
+    printTypeField(E->getThrownError(), Label::always("thrown_error"),
+                   PrintOptions::forDebugging(), TypeColor);
 
     printRec(E->getSubExpr(), Label::optional("sub_expr"));
     printFoot();
@@ -4553,10 +4547,8 @@ class PrintExpr : public ExprVisitor<PrintExpr, void, Label>,
   void visitTypeValueExpr(TypeValueExpr *E, Label label) {
     printCommon(E, "type_value_expr", label);
 
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
-    printTypeField(E->getParamType(), Label::always("param_type"), PO,
-                   TypeColor);
+    printTypeField(E->getParamType(), Label::always("param_type"),
+                   PrintOptions::forDebugging(), TypeColor);
 
     printFoot();
   }
@@ -6828,7 +6820,7 @@ void RequirementRepr::dump() const {
 }
 
 void GenericParamList::dump() const {
-  print(llvm::errs());
+  print(llvm::errs(), PrintOptions::forDebugging());
   llvm::errs() << '\n';
 }
 
@@ -6837,11 +6829,11 @@ void LayoutConstraint::dump() const {
     llvm::errs() << "(null)\n";
     return;
   }
-  getPointer()->print(llvm::errs());
+  getPointer()->print(llvm::errs(), PrintOptions::forDebugging());
 }
 
 void GenericSignature::dump() const {
-  print(llvm::errs());
+  print(llvm::errs(), PrintOptions::forDebugging());
   llvm::errs() << '\n';
 }
 
@@ -6876,7 +6868,7 @@ void InheritedEntry::dump(llvm::raw_ostream &os) const {
     os << '@' << getDumpString(getExplicitSafety()) << ' ';
   if (isSuppressed())
     os << "~";
-  getType().print(os);
+  getType().print(os, PrintOptions::forDebugging());
 }
 
 void InheritedEntry::dump() const { dump(llvm::errs()); }

lib/AST/ASTPrinter.cpp

@@ -6198,9 +6198,11 @@ class TypePrinter : public TypeVisitor<TypePrinter, void, NonRecursivePrintOptio
       if (Options.PrintTypesForDebugging || Options.PrintInSILBody)
         Printer << "@error_type ";
       visit(originalType);
-    }
-    else
+    } else if (Options.PrintTypesForDebugging) {
       Printer << "<<error type>>";
+    } else {
+      Printer << "_";
+    }
   }
 
   void visitUnresolvedType(UnresolvedType *T,

lib/IDE/SwiftSourceDocInfo.cpp

@@ -70,7 +70,8 @@ void XMLEscapingPrinter::printXML(StringRef Text) {
   OS << Text;
 }
 
-void ResolvedRangeInfo::print(llvm::raw_ostream &OS) const {
+void ResolvedRangeInfo::print(llvm::raw_ostream &OS,
+                              const PrintOptions &PO) const {
   OS << "<Kind>";
   switch (Kind) {
   case RangeKind::SingleExpression: OS << "SingleExpression"; break;
@@ -87,7 +88,7 @@ void ResolvedRangeInfo::print(llvm::raw_ostream &OS) const {
 
   if (auto Ty = getType()) {
     OS << "<Type>";
-    Ty->print(OS);
+    Ty->print(OS, PO);
     OS << "</Type>";
     switch(exit()) {
     case ExitState::Positive: OS << "<Exit>true</Exit>"; break;
@@ -147,7 +148,7 @@ void ResolvedRangeInfo::print(llvm::raw_ostream &OS) const {
   for (auto &RD : ReferencedDecls) {
     OS << "<Referenced>" << RD.VD->getBaseName() << "</Referenced>";
     OS << "<Type>";
-    RD.Ty->print(OS);
+    RD.Ty->print(OS, PO);
     OS << "</Type>\n";
   }
 

lib/Sema/CSBindings.cpp

@@ -2174,13 +2174,8 @@ void PotentialBindings::reset() {
   AssociatedCodeCompletionToken = ASTNode();
 }
 
-void PotentialBindings::dump(ConstraintSystem &cs,
-                             TypeVariableType *typeVar,
-                             llvm::raw_ostream &out,
-                             unsigned indent) const {
-  PrintOptions PO;
-  PO.PrintTypesForDebugging = true;
-
+void PotentialBindings::dump(ConstraintSystem &cs, TypeVariableType *typeVar,
+                             llvm::raw_ostream &out, unsigned indent) const {
   out << "Potential bindings for ";
   typeVar->getImpl().print(out);
   out << "\n";
@@ -2202,16 +2197,17 @@ void PotentialBindings::dump(ConstraintSystem &cs,
                [](auto lhs, auto rhs) {
                    return lhs.first->getID() < rhs.first->getID();
                });
-    interleave(adjacentVars,
-               [&](std::pair<TypeVariableType *, Constraint *> pair) {
-                 out << pair.first->getString(PO);
-                 if (pair.first->getImpl().getFixedType(/*record=*/nullptr))
-                   out << " (fixed)";
-                 out << " via ";
-                 pair.second->print(out, &cs.getASTContext().SourceMgr, indent,
-                                    /*skipLocator=*/true);
-               },
-               [&out]() { out << ", "; });
+    interleave(
+        adjacentVars,
+        [&](std::pair<TypeVariableType *, Constraint *> pair) {
+          out << pair.first->getString(PrintOptions::forDebugging());
+          if (pair.first->getImpl().getFixedType(/*record=*/nullptr))
+            out << " (fixed)";
+          out << " via ";
+          pair.second->print(out, &cs.getASTContext().SourceMgr, indent,
+                             /*skipLocator=*/true);
+        },
+        [&out]() { out << ", "; });
     out << "] ";
   }
 }
@@ -2295,8 +2291,7 @@ static std::string getCollectionLiteralAsString(KnownProtocolKind KPK) {
 }
 
 void BindingSet::dump(llvm::raw_ostream &out, unsigned indent) const {
-  PrintOptions PO;
-  PO.PrintTypesForDebugging = true;
+  PrintOptions PO = PrintOptions::forDebugging();
 
   if (auto typeVar = getTypeVariable()) {
     typeVar->getImpl().print(out);
@@ -2991,8 +2986,7 @@ bool TypeVariableBinding::attempt(ConstraintSystem &cs) const {
 
   if (result.isFailure()) {
     if (cs.isDebugMode()) {
-      PrintOptions PO;
-      PO.PrintTypesForDebugging = true;
+      PrintOptions PO = PrintOptions::forDebugging();
 
       llvm::errs().indent(cs.solverState->getCurrentIndent())
           << "(failed to establish binding " << TypeVar->getString(PO)

lib/Sema/CSOptimizer.cpp

@@ -1738,13 +1738,11 @@ static void determineBestChoicesInContext(
         });
 
     if (cs.isDebugMode()) {
-      PrintOptions PO;
-      PO.PrintTypesForDebugging = true;
 
       llvm::errs().indent(cs.solverState->getCurrentIndent())
           << "<<< Disjunction "
           << disjunction->getNestedConstraints()[0]->getFirstType()->getString(
-                 PO)
+                 PrintOptions::forDebugging())
           << " with score " << bestScore << "\n";
     }
 
@@ -1774,8 +1772,7 @@ static void determineBestChoicesInContext(
   }
 
   if (cs.isDebugMode() && bestOverallScore > 0) {
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
+    PrintOptions PO = PrintOptions::forDebugging();
 
     auto getLogger = [&](unsigned extraIndent = 0) -> llvm::raw_ostream & {
       return llvm::errs().indent(cs.solverState->getCurrentIndent() +

lib/Sema/CSSimplify.cpp

@@ -13439,12 +13439,9 @@ bool ConstraintSystem::simplifyAppliedOverloadsImpl(
   // If we have a common result type, bind the expected result type to it.
   if (commonResultType && !commonResultType->is<ErrorType>()) {
     if (isDebugMode()) {
-      PrintOptions PO;
-      PO.PrintTypesForDebugging = true;
       llvm::errs().indent(solverState ? solverState->getCurrentIndent() : 0)
-        << "(common result type for $T" << fnTypeVar->getID() << " is "
-        << commonResultType.getString(PO)
-        << ")\n";
+          << "(common result type for $T" << fnTypeVar->getID() << " is "
+          << commonResultType.getString(PrintOptions::forDebugging()) << ")\n";
     }
 
     // Introduction of a `Bind` constraint here could result in the disconnect

lib/Sema/CSStep.cpp

@@ -280,13 +280,11 @@ StepResult ComponentStep::take(bool prevFailed) {
     CS.collectDisjunctions(disjunctions);
     std::vector<std::string> overloadDisjunctions;
     for (const auto &disjunction : disjunctions) {
-      PrintOptions PO;
-      PO.PrintTypesForDebugging = true;
-
       auto constraints = disjunction->getNestedConstraints();
       if (constraints[0]->getKind() == ConstraintKind::BindOverload)
         overloadDisjunctions.push_back(
-            constraints[0]->getFirstType()->getString(PO));
+            constraints[0]->getFirstType()->getString(
+                PrintOptions::forDebugging()));
     }
 
     if (!potentialBindings.empty() || !overloadDisjunctions.empty()) {
@@ -357,14 +355,11 @@ StepResult ComponentStep::take(bool prevFailed) {
     // we can't solve this system unless we have free type variables
     // allowed in the solution.
     if (CS.isDebugMode()) {
-      PrintOptions PO;
-      PO.PrintTypesForDebugging = true;
-
       auto &log = getDebugLogger();
       log << "(failed due to free variables:";
       for (auto *typeVar : CS.getTypeVariables()) {
         if (!typeVar->getImpl().hasRepresentativeOrFixed()) {
-          log << " " << typeVar->getString(PO);
+          log << " " << typeVar->getString(PrintOptions::forDebugging());
         }
       }
       log << ")\n";

lib/Sema/CSStep.h

@@ -407,15 +407,12 @@ class ComponentStep final : public SolverStep {
       auto &log = getDebugLogger();
       log << "Type variables in scope = "
           << "[";
-      auto typeVars = CS.getTypeVariables();
-      PrintOptions PO;
-      PO.PrintTypesForDebugging = true;
-      interleave(typeVars, [&](TypeVariableType *typeVar) {
-                   Type(typeVar).print(log, PO);
-                 },
-                 [&] {
-                   log << ", ";
-                 });
+      interleave(
+          CS.getTypeVariables(),
+          [&](TypeVariableType *typeVar) {
+            Type(typeVar).print(log, PrintOptions::forDebugging());
+          },
+          [&] { log << ", "; });
       log << "]" << '\n';
     }
 
@@ -553,9 +550,8 @@ class TypeVariableStep final : public BindingStep<TypeVarBindingProducer> {
   StepResult resume(bool prevFailed) override;
 
   void print(llvm::raw_ostream &Out) override {
-    PrintOptions PO;
-    PO.PrintTypesForDebugging = true;
-    Out << "TypeVariableStep for " << TypeVar->getString(PO) << '\n';
+    Out << "TypeVariableStep for ";
+    Out << TypeVar->getString(PrintOptions::forDebugging()) << '\n';
   }
 
 protected:

lib/Sema/CSTrail.cpp

@@ -577,8 +577,7 @@ void SolverTrail::Change::undo(ConstraintSystem &cs) const {
 void SolverTrail::Change::dump(llvm::raw_ostream &out,
                                ConstraintSystem &cs,
                                unsigned indent) const {
-  PrintOptions PO;
-  PO.PrintTypesForDebugging = true;
+  PrintOptions PO = PrintOptions::forDebugging();
 
   out.indent(indent);
 
@@ -887,8 +886,7 @@ void SolverTrail::dumpActiveScopeChanges(llvm::raw_ostream &out,
   llvm::set_subtract(removedConstraints, intersects);
 
   // Print out Changes.
-  PrintOptions PO;
-  PO.PrintTypesForDebugging = true;
+  PrintOptions PO = PrintOptions::forDebugging();
   out.indent(indent);
   out << "(Changes:\n";
   if (!addedTypeVars.empty()) {

lib/Sema/Constraint.cpp

@@ -338,8 +338,7 @@ ProtocolDecl *Constraint::getProtocol() const {
 void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm,
                        unsigned indent, bool skipLocator) const {
   // Print all type variables as $T0 instead of _ here.
-  PrintOptions PO;
-  PO.PrintTypesForDebugging = true;
+  PrintOptions PO = PrintOptions::forDebugging();
 
   if (Kind == ConstraintKind::Disjunction ||
       Kind == ConstraintKind::Conjunction) {