[AST] Break recursion in SubstitutionMap::dump too.

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.

lib/AST/ASTDumper.cpp

@@ -2800,6 +2800,11 @@ static void dumpProtocolConformanceRec(
     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,
@@ -2905,8 +2910,9 @@ static void dumpProtocolConformanceRec(
       break;
 
     out << '\n';
-    conf->getSubstitutionMap().dump(out, SubstitutionMap::DumpStyle::Full,
-                                    indent + 2);
+    dumpSubstitutionMapRec(conf->getSubstitutionMap(), out,
+                           SubstitutionMap::DumpStyle::Full, indent + 2,
+                           visited);
     out << '\n';
     for (auto subReq : conf->getConditionalRequirements()) {
       out.indent(indent + 2);
@@ -2922,31 +2928,11 @@ static void dumpProtocolConformanceRec(
   PrintWithColorRAII(out, ParenthesisColor) << ')';
 }
 
-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,
-                           SubstitutionMap::DumpStyle style,
-                           unsigned indent) const {
-  auto *genericSig = getGenericSignature();
+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) {
@@ -2962,7 +2948,8 @@ void SubstitutionMap::dump(llvm::raw_ostream &out,
 
   genericSig->print(out);
   auto genericParams = genericSig->getGenericParams();
-  auto replacementTypes = getReplacementTypesBuffer();
+  auto replacementTypes =
+      static_cast<const SubstitutionMap &>(map).getReplacementTypesBuffer();
   for (unsigned i : indices(genericParams)) {
     if (style == SubstitutionMap::DumpStyle::Minimal) {
       out << " ";
@@ -2985,9 +2972,7 @@ void SubstitutionMap::dump(llvm::raw_ostream &out,
   if (style == SubstitutionMap::DumpStyle::Minimal)
     return;
 
-  // We only really need to print a conformance once across this whole map.
-  llvm::SmallPtrSet<const ProtocolConformance *, 8> visited;
-  auto conformances = getConformances();
+  auto conformances = map.getConformances();
   for (const auto &req : genericSig->getRequirements()) {
     if (req.getKind() != RequirementKind::Conformance)
       continue;
@@ -3006,6 +2991,33 @@ void SubstitutionMap::dump(llvm::raw_ostream &out,
   }
 }
 
+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";

test/Driver/debug-generic-signatures.swift

@@ -21,6 +21,16 @@ protocol P2 {
     associatedtype B: P2 where Self.A.A == Self.B.A
 }
 
+// Simpler recursion
+// CHECK: Generic signature: <Self where Self : P3>
+// CHECK-NEXT: Canonical generic signature: <τ_0_0 where τ_0_0 : P3>
+// CHECK-LABEL: main.(file).P3@
+// CHECK: Requirement signature: <Self where Self.A : P3>
+// CHECK-NEXT: Canonical requirement signature: <τ_0_0 where τ_0_0.A : P3>
+protocol P3 {
+    associatedtype A: P3
+}
+
 // CHECK-LABEL: StructDecl name=Basic
 // CHECK: (normal_conformance type=Basic protocol=P1
 // CHECK-NEXT: (assoc_type req=A type=Basic.A)
@@ -118,3 +128,29 @@ extension Super: P2 where T: P2, U: P2 {
 // CHECK-NEXT:       conforms_to: T P2
 // CHECK-NEXT:       conforms_to: U P2)))
 class Sub: Super<NonRecur, Recur> {}
+
+// Specialization of a recursive conformance should be okay: recursion detection
+// should work through SubstitutionMaps.
+
+// CHECK-LABEL: StructDecl name=RecurGeneric
+// CHECK-NEXT: (normal_conformance type=RecurGeneric<T> protocol=P3
+// CHECK-NEXT:   (assoc_type req=A type=RecurGeneric<T>.A)
+// CHECK-NEXT:   (normal_conformance type=RecurGeneric<T> protocol=P3 (details printed above)))
+struct RecurGeneric<T: P3>: P3 {
+    typealias A = RecurGeneric<T>
+}
+
+// CHECK-LABEL: StructDecl name=Specialize
+// CHECK-NEXT: (normal_conformance type=Specialize protocol=P3
+// CHECK-NEXT:   (assoc_type req=A type=Specialize.A)
+// CHECK-NEXT:   (specialized_conformance type=Specialize.A protocol=P3
+// CHECK-NEXT:     (substitution_map generic_signature=<T where T : P3>
+// CHECK-NEXT:       (substitution T -> Specialize)
+// CHECK-NEXT:       (conformance type=T
+// CHECK-NEXT:         (normal_conformance type=Specialize protocol=P3 (details printed above))))
+// CHECK-NEXT:     (normal_conformance type=RecurGeneric<T> protocol=P3
+// CHECK-NEXT:       (assoc_type req=A type=RecurGeneric<T>.A)
+// CHECK-NEXT:       (normal_conformance type=RecurGeneric<T> protocol=P3 (details printed above)))))
+struct Specialize: P3 {
+    typealias A = RecurGeneric<Specialize>
+}