NFC: Extract simple_display for FileUnit

Author: hamishknight

include/swift/AST/FileUnit.h

@@ -369,6 +369,7 @@ class LoadedFile : public FileUnit {
   }
 };
 
+void simple_display(llvm::raw_ostream &out, const FileUnit *file);
 
 inline FileUnit &ModuleDecl::getMainFile(FileUnitKind expectedKind) const {
   assert(expectedKind != FileUnitKind::Source &&

lib/AST/Module.cpp

@@ -1895,6 +1895,28 @@ void FileUnit::getTopLevelDeclsWhereAttributesMatch(
   Results.erase(newEnd, Results.end());
 }
 
+void swift::simple_display(llvm::raw_ostream &out, const FileUnit *file) {
+  if (!file) {
+    out << "(null)";
+    return;
+  }
+
+  switch (file->getKind()) {
+  case FileUnitKind::Source:
+    out << '\"' << cast<SourceFile>(file)->getFilename() << '\"';
+    return;
+  case FileUnitKind::Builtin:
+    out << "(Builtin)";
+    return;
+  case FileUnitKind::DWARFModule:
+  case FileUnitKind::ClangModule:
+  case FileUnitKind::SerializedAST:
+    out << '\"' << cast<LoadedFile>(file)->getFilename() << '\"';
+    return;
+  }
+  llvm_unreachable("Unhandled case in switch");
+}
+
 StringRef LoadedFile::getFilename() const {
   return "";
 }

lib/SILGen/SILGenRequests.cpp

@@ -38,19 +38,7 @@ void swift::simple_display(llvm::raw_ostream &out,
   } else {
     assert(unit);
     out << "SIL Generation for file ";
-    switch (unit->getKind()) {
-    case FileUnitKind::Source:
-      out << '\"' << cast<SourceFile>(unit)->getFilename() << '\"';
-      break;
-    case FileUnitKind::Builtin:
-      out << "(Builtin)";
-      break;
-    case FileUnitKind::DWARFModule:
-    case FileUnitKind::ClangModule:
-    case FileUnitKind::SerializedAST:
-      out << '\"' << cast<LoadedFile>(unit)->getFilename() << '\"';
-      break;
-    }
+    simple_display(out, unit);
   }
 }