[AST] Add printing for Clang function types in SIL.

Author: varungandhi-apple

include/swift/AST/Types.h

@@ -3900,6 +3900,11 @@ class SILFunctionType final : public TypeBase, public llvm::FoldingSetNode,
 
       bool empty() const { return !ClangFunctionType; }
       Uncommon(const clang::FunctionType *type) : ClangFunctionType(type) {}
+
+    public:
+      /// Analog of AnyFunctionType::ExtInfo::Uncommon::printClangFunctionType.
+      void printClangFunctionType(ClangModuleLoader *cml,
+                                  llvm::raw_ostream &os) const;
     };
 
     Uncommon Other;

lib/AST/ASTContext.cpp

@@ -3156,6 +3156,11 @@ ArrayRef<Requirement> GenericFunctionType::getRequirements() const {
   return Signature->getRequirements();
 }
 
+void SILFunctionType::ExtInfo::Uncommon::printClangFunctionType(
+    ClangModuleLoader *cml, llvm::raw_ostream &os) const {
+  cml->printClangType(ClangFunctionType, os);
+}
+
 void SILFunctionType::Profile(
     llvm::FoldingSetNodeID &id,
     GenericSignature genericParams,

lib/AST/ASTPrinter.cpp

@@ -3911,7 +3911,8 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
     }
   }
 
-  void printFunctionExtInfo(SILFunctionType::ExtInfo info,
+  void printFunctionExtInfo(ASTContext &Ctx,
+                            SILFunctionType::ExtInfo info,
                             ProtocolConformanceRef witnessMethodConformance) {
     if (Options.SkipAttributes)
       return;
@@ -3925,10 +3926,19 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
       }
     }
 
-    if ((Options.PrintFunctionRepresentationAttrs !=
-         PrintOptions::FunctionRepresentationMode::None) &&
-        !Options.excludeAttrKind(TAK_convention) &&
-        info.getRepresentation() != SILFunctionType::Representation::Thick) {
+
+    SmallString<64> buf;
+    switch (Options.PrintFunctionRepresentationAttrs) {
+    case PrintOptions::FunctionRepresentationMode::None:
+      break;
+    case PrintOptions::FunctionRepresentationMode::NameOnly:
+    case PrintOptions::FunctionRepresentationMode::Full:
+      if (Options.excludeAttrKind(TAK_convention) ||
+          info.getRepresentation() == SILFunctionType::Representation::Thick)
+        break;
+
+      bool printNameOnly = Options.PrintFunctionRepresentationAttrs ==
+                           PrintOptions::FunctionRepresentationMode::NameOnly;
       Printer.callPrintStructurePre(PrintStructureKind::BuiltinAttribute);
       Printer.printAttrName("@convention");
       Printer << "(";
@@ -3943,6 +3953,11 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
         break;
       case SILFunctionType::Representation::CFunctionPointer:
         Printer << "c";
+        // FIXME: [clang-function-type-serialization] Once we start serializing
+        // Clang function types, we should be able to remove the second check.
+        if (printNameOnly || !info.getUncommonInfo().hasValue())
+          break;
+        printCType(Ctx, Printer, info);
         break;
       case SILFunctionType::Representation::Method:
         Printer << "method";
@@ -4102,7 +4117,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
 
   void visitSILFunctionType(SILFunctionType *T) {
     printSILCoroutineKind(T->getCoroutineKind());
-    printFunctionExtInfo(T->getExtInfo(),
+    printFunctionExtInfo(T->getASTContext(), T->getExtInfo(),
                          T->getWitnessMethodConformanceOrInvalid());
     printCalleeConvention(T->getCalleeConvention());