Add a PrettyStackTrace for working with Clang types.

Author: rjmccall

include/swift/AST/PrettyStackTrace.h

@@ -24,6 +24,10 @@
 #include "swift/AST/Identifier.h"
 #include "swift/AST/Type.h"
 
+namespace clang {
+  class Type;
+}
+
 namespace swift {
   class ASTContext;
   class Decl;
@@ -132,6 +136,17 @@ class PrettyStackTraceType : public llvm::PrettyStackTraceEntry {
   virtual void print(llvm::raw_ostream &OS) const;
 };
 
+/// PrettyStackTraceClangType - Observe that we are processing a
+/// specific Clang type.
+class PrettyStackTraceClangType : public llvm::PrettyStackTraceEntry {
+  const clang::Type *TheType;
+  const char *Action;
+public:
+  PrettyStackTraceClangType(const char *action, const clang::Type *type)
+    : TheType(type), Action(action) {}
+  virtual void print(llvm::raw_ostream &OS) const;
+};
+
 /// Observe that we are processing a specific type representation.
 class PrettyStackTraceTypeRepr : public llvm::PrettyStackTraceEntry {
   ASTContext &Context;

lib/AST/PrettyStackTrace.cpp

@@ -27,6 +27,7 @@
 #include "swift/AST/TypeRepr.h"
 #include "swift/AST/TypeVisitor.h"
 #include "swift/Basic/SourceManager.h"
+#include "clang/AST/Type.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/MemoryBuffer.h"
 
@@ -209,6 +210,15 @@ void swift::printTypeDescription(llvm::raw_ostream &out, Type type,
   if (addNewline) out << '\n';
 }
 
+void PrettyStackTraceClangType::print(llvm::raw_ostream &out) const {
+  out << "While " << Action << ' ';
+  if (TheType == nullptr) {
+    out << "NULL clang type!\n";
+    return;
+  }
+  TheType->dump(out);
+}
+
 void PrettyStackTraceTypeRepr::print(llvm::raw_ostream &out) const {
   out << "While " << Action << " type ";
   TheType->print(out);