Merge pull request #16622 from huonw/better-protocol-conformance-printing

Better protocol conformance and substitution map printing

Author: huonw

include/swift/AST/SubstitutionMap.h

@@ -71,13 +71,17 @@ class SubstitutionMap {
   /// signature nor any replacement types/conformances.
   Storage *storage = nullptr;
 
+public:
   /// Retrieve the array of replacement types, which line up with the
   /// generic parameters.
   ///
   /// Note that the types may be null, for cases where the generic parameter
   /// is concrete but hasn't been queried yet.
+  ///
+  /// Prefer \c getReplacementTypes, this is public for printing purposes.
   ArrayRef<Type> getReplacementTypesBuffer() const;
 
+private:
   MutableArrayRef<Type> getReplacementTypesBuffer();
 
   /// Retrieve a mutable reference to the buffer of conformances.
@@ -218,8 +222,12 @@ class SubstitutionMap {
   /// Verify that this substitution map is valid.
   void verify() const;
 
+  /// Whether to dump the full substitution map, or just a minimal useful subset
+  /// (on a single line).
+  enum class DumpStyle { Minimal, Full };
   /// Dump the contents of this substitution map for debugging purposes.
-  void dump(llvm::raw_ostream &out) const;
+  void dump(llvm::raw_ostream &out, DumpStyle style = DumpStyle::Full,
+            unsigned indent = 0) const;
 
   LLVM_ATTRIBUTE_DEPRECATED(void dump() const, "only for use in the debugger");
 

lib/AST/ASTDumper.cpp

@@ -23,6 +23,7 @@
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/ProtocolConformance.h"
 #include "swift/AST/TypeVisitor.h"
+#include "swift/Basic/Defer.h"
 #include "swift/Basic/QuotedString.h"
 #include "swift/Basic/STLExtras.h"
 #include "llvm/ADT/APFloat.h"
@@ -2792,55 +2793,74 @@ void TypeRepr::dump() const {
   llvm::errs() << '\n';
 }
 
-void ProtocolConformanceRef::dump() const {
-  dump(llvm::errs());
-}
-
-void ProtocolConformanceRef::dump(llvm::raw_ostream &out,
-                                  unsigned indent) const {
-  if (isConcrete()) {
-    getConcrete()->dump(out, indent);
+// Recursive helpers to avoid infinite recursion for recursive protocol
+// conformances.
+static void dumpProtocolConformanceRec(
+    const ProtocolConformance *conformance, llvm::raw_ostream &out,
+    unsigned indent,
+    llvm::SmallPtrSetImpl<const ProtocolConformance *> &visited);
+
+static void dumpSubstitutionMapRec(
+    SubstitutionMap map, llvm::raw_ostream &out,
+    SubstitutionMap::DumpStyle style, unsigned indent,
+    llvm::SmallPtrSetImpl<const ProtocolConformance *> &visited);
+
+static void dumpProtocolConformanceRefRec(
+    const ProtocolConformanceRef conformance, llvm::raw_ostream &out,
+    unsigned indent,
+    llvm::SmallPtrSetImpl<const ProtocolConformance *> &visited) {
+  if (conformance.isConcrete()) {
+    dumpProtocolConformanceRec(conformance.getConcrete(), out, indent, visited);
   } else {
     out.indent(indent) << "(abstract_conformance protocol="
-                       << getAbstract()->getName();
+                       << conformance.getAbstract()->getName();
     PrintWithColorRAII(out, ParenthesisColor) << ')';
-    out << '\n';
   }
 }
 
-void ProtocolConformance::dump() const {
-  auto &out = llvm::errs();
-  dump(out);
-  out << '\n';
-}
+static void dumpProtocolConformanceRec(
+    const ProtocolConformance *conformance, llvm::raw_ostream &out,
+    unsigned indent,
+    llvm::SmallPtrSetImpl<const ProtocolConformance *> &visited) {
+  // A recursive conformance shouldn't have its contents printed, or there's
+  // infinite recursion. (This also avoids printing things that occur multiple
+  // times in a conformance hierarchy.)
+  auto shouldPrintDetails = visited.insert(conformance).second;
 
-void ProtocolConformance::dump(llvm::raw_ostream &out, unsigned indent) const {
   auto printCommon = [&](StringRef kind) {
     out.indent(indent);
     PrintWithColorRAII(out, ParenthesisColor) << '(';
-    out << kind << "_conformance type=" << getType()
-        << " protocol=" << getProtocol()->getName();
+    out << kind << "_conformance type=" << conformance->getType()
+        << " protocol=" << conformance->getProtocol()->getName();
+
+    if (!shouldPrintDetails)
+      out << " (details printed above)";
   };
 
-  switch (getKind()) {
+  switch (conformance->getKind()) {
   case ProtocolConformanceKind::Normal: {
-    auto normal = cast<NormalProtocolConformance>(this);
+    auto normal = cast<NormalProtocolConformance>(conformance);
 
     printCommon("normal");
+    if (!shouldPrintDetails)
+      break;
+
     // Maybe print information about the conforming context?
     if (normal->isLazilyLoaded()) {
       out << " lazy";
     } else {
-      forEachTypeWitness(nullptr, [&](const AssociatedTypeDecl *req,
-                                      Type ty, const TypeDecl *) -> bool {
-        out << '\n';
-        out.indent(indent + 2);
-        PrintWithColorRAII(out, ParenthesisColor) << '(';
-        out << "assoc_type req=" << req->getName() << " type=";
-        PrintWithColorRAII(out, TypeColor) << ty;
-        PrintWithColorRAII(out, ParenthesisColor) << ')';
-        return false;
-      });
+      normal->forEachTypeWitness(
+          nullptr,
+          [&](const AssociatedTypeDecl *req, Type ty,
+              const TypeDecl *) -> bool {
+            out << '\n';
+            out.indent(indent + 2);
+            PrintWithColorRAII(out, ParenthesisColor) << '(';
+            out << "assoc_type req=" << req->getName() << " type=";
+            PrintWithColorRAII(out, TypeColor) << Type(ty->getDesugaredType());
+            PrintWithColorRAII(out, ParenthesisColor) << ')';
+            return false;
+          });
       normal->forEachValueWitness(nullptr, [&](const ValueDecl *req,
                                                Witness witness) {
         out << '\n';
@@ -2857,9 +2877,9 @@ void ProtocolConformance::dump(llvm::raw_ostream &out, unsigned indent) const {
         PrintWithColorRAII(out, ParenthesisColor) << ')';
       });
 
-      for (auto conformance : normal->getSignatureConformances()) {
+      for (auto sigConf : normal->getSignatureConformances()) {
         out << '\n';
-        conformance.dump(out, indent + 2);
+        dumpProtocolConformanceRefRec(sigConf, out, indent + 2, visited);
       }
     }
 
@@ -2872,31 +2892,137 @@ void ProtocolConformance::dump(llvm::raw_ostream &out, unsigned indent) const {
   }
 
   case ProtocolConformanceKind::Inherited: {
-    auto conf = cast<InheritedProtocolConformance>(this);
+    auto conf = cast<InheritedProtocolConformance>(conformance);
     printCommon("inherited");
+    if (!shouldPrintDetails)
+      break;
+
     out << '\n';
-    conf->getInheritedConformance()->dump(out, indent + 2);
+    dumpProtocolConformanceRec(conf->getInheritedConformance(), out, indent + 2,
+                               visited);
     break;
   }
 
   case ProtocolConformanceKind::Specialized: {
-    auto conf = cast<SpecializedProtocolConformance>(this);
+    auto conf = cast<SpecializedProtocolConformance>(conformance);
     printCommon("specialized");
+    if (!shouldPrintDetails)
+      break;
+
+    out << '\n';
+    dumpSubstitutionMapRec(conf->getSubstitutionMap(), out,
+                           SubstitutionMap::DumpStyle::Full, indent + 2,
+                           visited);
     out << '\n';
-    conf->getSubstitutionMap().dump(out);
     for (auto subReq : conf->getConditionalRequirements()) {
       out.indent(indent + 2);
       subReq.dump(out);
       out << '\n';
     }
-    conf->getGenericConformance()->dump(out, indent + 2);
+    dumpProtocolConformanceRec(conf->getGenericConformance(), out, indent + 2,
+                               visited);
     break;
   }
   }
 
   PrintWithColorRAII(out, ParenthesisColor) << ')';
 }
 
+static void dumpSubstitutionMapRec(
+    SubstitutionMap map, llvm::raw_ostream &out,
+    SubstitutionMap::DumpStyle style, unsigned indent,
+    llvm::SmallPtrSetImpl<const ProtocolConformance *> &visited) {
+  auto *genericSig = map.getGenericSignature();
+  out.indent(indent);
+
+  auto printParen = [&](char p) {
+    PrintWithColorRAII(out, ParenthesisColor) << p;
+  };
+  printParen('(');
+  SWIFT_DEFER { printParen(')'); };
+  out << "substitution_map generic_signature=";
+  if (genericSig == nullptr) {
+    out << "<nullptr>";
+    return;
+  }
+
+  genericSig->print(out);
+  auto genericParams = genericSig->getGenericParams();
+  auto replacementTypes =
+      static_cast<const SubstitutionMap &>(map).getReplacementTypesBuffer();
+  for (unsigned i : indices(genericParams)) {
+    if (style == SubstitutionMap::DumpStyle::Minimal) {
+      out << " ";
+    } else {
+      out << "\n";
+      out.indent(indent + 2);
+    }
+    printParen('(');
+    out << "substitution ";
+    genericParams[i]->print(out);
+    out << " -> ";
+    if (replacementTypes[i])
+      replacementTypes[i]->print(out);
+    else
+      out << "<<unresolved concrete type>>";
+    printParen(')');
+  }
+  // A minimal dump doesn't need the details about the conformances, a lot of
+  // that info can be inferred from the signature.
+  if (style == SubstitutionMap::DumpStyle::Minimal)
+    return;
+
+  auto conformances = map.getConformances();
+  for (const auto &req : genericSig->getRequirements()) {
+    if (req.getKind() != RequirementKind::Conformance)
+      continue;
+
+    out << "\n";
+    out.indent(indent + 2);
+    printParen('(');
+    out << "conformance type=";
+    req.getFirstType()->print(out);
+    out << "\n";
+    dumpProtocolConformanceRefRec(conformances.front(), out, indent + 4,
+                                  visited);
+
+    printParen(')');
+    conformances = conformances.slice(1);
+  }
+}
+
+void ProtocolConformanceRef::dump() const {
+  dump(llvm::errs());
+  llvm::errs() << '\n';
+}
+
+void ProtocolConformanceRef::dump(llvm::raw_ostream &out,
+                                  unsigned indent) const {
+  llvm::SmallPtrSet<const ProtocolConformance *, 8> visited;
+  dumpProtocolConformanceRefRec(*this, out, indent, visited);
+}
+void ProtocolConformance::dump() const {
+  auto &out = llvm::errs();
+  dump(out);
+  out << '\n';
+}
+
+void ProtocolConformance::dump(llvm::raw_ostream &out, unsigned indent) const {
+  llvm::SmallPtrSet<const ProtocolConformance *, 8> visited;
+  dumpProtocolConformanceRec(this, out, indent, visited);
+}
+
+void SubstitutionMap::dump(llvm::raw_ostream &out, DumpStyle style,
+                           unsigned indent) const {
+  llvm::SmallPtrSet<const ProtocolConformance *, 8> visited;
+  dumpSubstitutionMapRec(*this, out, style, indent, visited);
+}
+
+void SubstitutionMap::dump() const {
+  dump(llvm::errs());
+  llvm::errs() << "\n";
+}
+
 //===----------------------------------------------------------------------===//
 // Dumping for Types.
 //===----------------------------------------------------------------------===//

lib/AST/ConcreteDeclRef.cpp

@@ -56,7 +56,7 @@ void ConcreteDeclRef::dump(raw_ostream &os) {
   // If specialized, dump the substitutions.
   if (isSpecialized()) {
     os << " [with ";
-    getSubstitutions().dump(os);
+    getSubstitutions().dump(os, SubstitutionMap::DumpStyle::Minimal);
     os << ']';
   }
 }

lib/AST/SubstitutionMap.cpp

@@ -615,48 +615,6 @@ void SubstitutionMap::verify() const {
 #endif
 }
 
-void SubstitutionMap::dump(llvm::raw_ostream &out) const {
-  auto *genericSig = getGenericSignature();
-  if (genericSig == nullptr) {
-    out << "Empty substitution map\n";
-    return;
-  }
-  out << "Generic signature: ";
-  genericSig->print(out);
-  out << "\n";
-  out << "Substitutions:\n";
-  auto genericParams = genericSig->getGenericParams();
-  auto replacementTypes = getReplacementTypesBuffer();
-  for (unsigned i : indices(genericParams)) {
-    out.indent(2);
-    genericParams[i]->print(out);
-    out << " -> ";
-    if (replacementTypes[i])
-      replacementTypes[i]->print(out);
-    else
-      out << "<<unresolved concrete type>>";
-    out << "\n";
-  }
-
-  out << "\nConformance map:\n";
-  auto conformances = getConformances();
-  for (const auto &req : genericSig->getRequirements()) {
-    if (req.getKind() != RequirementKind::Conformance) continue;
-
-    out.indent(2);
-    req.getFirstType()->print(out);
-    out << " -> ";
-    conformances.front().dump(out);
-    out << "\n";
-
-    conformances = conformances.slice(1);
-  }
-}
-
-void SubstitutionMap::dump() const {
-  return dump(llvm::errs());
-}
-
 void SubstitutionMap::profile(llvm::FoldingSetNodeID &id) const {
   id.AddPointer(storage);
 }

lib/Sema/TypeCheckProtocol.cpp

@@ -4668,17 +4668,20 @@ void TypeChecker::checkConformancesInContext(DeclContext *dc,
         inferStaticInitializeObjCMetadata(*this, classDecl);
       }
     }
+  }
+
+  // Check all conformances.
+  groupChecker.checkAllConformances();
 
-    // When requested, print out information about this conformance.
-    if (Context.LangOpts.DebugGenericSignatures) {
+  if (Context.LangOpts.DebugGenericSignatures) {
+    // Now that they're filled out, print out information about the conformances
+    // here, when requested.
+    for (auto conformance : conformances) {
       dc->dumpContext();
       conformance->dump();
     }
   }
 
-  // Check all conformances.
-  groupChecker.checkAllConformances();
-
   // Catalog all of members of this declaration context that satisfy
   // requirements of conformances in this context.
   SmallVector<ValueDecl *, 16>