diff --git a/mlir/examples/toy/Ch2/include/toy/CMakeLists.txt b/mlir/examples/toy/Ch2/include/toy/CMakeLists.txt
--- a/mlir/examples/toy/Ch2/include/toy/CMakeLists.txt
+++ b/mlir/examples/toy/Ch2/include/toy/CMakeLists.txt
@@ -2,4 +2,5 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(Dialect.h.inc -gen-dialect-decls)
+mlir_tablegen(Dialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(ToyCh2OpsIncGen)
diff --git a/mlir/examples/toy/Ch3/include/toy/CMakeLists.txt b/mlir/examples/toy/Ch3/include/toy/CMakeLists.txt
--- a/mlir/examples/toy/Ch3/include/toy/CMakeLists.txt
+++ b/mlir/examples/toy/Ch3/include/toy/CMakeLists.txt
@@ -2,4 +2,5 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(Dialect.h.inc -gen-dialect-decls)
+mlir_tablegen(Dialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(ToyCh3OpsIncGen)
diff --git a/mlir/examples/toy/Ch4/include/toy/CMakeLists.txt b/mlir/examples/toy/Ch4/include/toy/CMakeLists.txt
--- a/mlir/examples/toy/Ch4/include/toy/CMakeLists.txt
+++ b/mlir/examples/toy/Ch4/include/toy/CMakeLists.txt
@@ -3,6 +3,7 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(Dialect.h.inc -gen-dialect-decls)
+mlir_tablegen(Dialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(ToyCh4OpsIncGen)
 
 # Most dialects should use add_mlir_interfaces().
diff --git a/mlir/examples/toy/Ch5/include/toy/CMakeLists.txt b/mlir/examples/toy/Ch5/include/toy/CMakeLists.txt
--- a/mlir/examples/toy/Ch5/include/toy/CMakeLists.txt
+++ b/mlir/examples/toy/Ch5/include/toy/CMakeLists.txt
@@ -3,6 +3,7 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(Dialect.h.inc -gen-dialect-decls)
+mlir_tablegen(Dialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(ToyCh5OpsIncGen)
 
 # Most dialects should use add_mlir_interfaces().
diff --git a/mlir/examples/toy/Ch6/include/toy/CMakeLists.txt b/mlir/examples/toy/Ch6/include/toy/CMakeLists.txt
--- a/mlir/examples/toy/Ch6/include/toy/CMakeLists.txt
+++ b/mlir/examples/toy/Ch6/include/toy/CMakeLists.txt
@@ -3,6 +3,7 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(Dialect.h.inc -gen-dialect-decls)
+mlir_tablegen(Dialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(ToyCh6OpsIncGen)
 
 # Most dialects should use add_mlir_interfaces().
diff --git a/mlir/examples/toy/Ch7/include/toy/CMakeLists.txt b/mlir/examples/toy/Ch7/include/toy/CMakeLists.txt
--- a/mlir/examples/toy/Ch7/include/toy/CMakeLists.txt
+++ b/mlir/examples/toy/Ch7/include/toy/CMakeLists.txt
@@ -3,6 +3,7 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(Dialect.h.inc -gen-dialect-decls)
+mlir_tablegen(Dialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(ToyCh7OpsIncGen)
 
 # Most dialects should use add_mlir_interfaces().
diff --git a/mlir/include/mlir/Dialect/LLVMIR/CMakeLists.txt b/mlir/include/mlir/Dialect/LLVMIR/CMakeLists.txt
--- a/mlir/include/mlir/Dialect/LLVMIR/CMakeLists.txt
+++ b/mlir/include/mlir/Dialect/LLVMIR/CMakeLists.txt
@@ -9,6 +9,7 @@
 mlir_tablegen(LLVMOps.h.inc -gen-op-decls)
 mlir_tablegen(LLVMOps.cpp.inc -gen-op-defs)
 mlir_tablegen(LLVMOpsDialect.h.inc -gen-dialect-decls)
+mlir_tablegen(LLVMOpsDialect.cpp.inc -gen-dialect-defs)
 mlir_tablegen(LLVMOpsEnums.h.inc -gen-enum-decls)
 mlir_tablegen(LLVMOpsEnums.cpp.inc -gen-enum-defs)
 add_public_tablegen_target(MLIRLLVMOpsIncGen)
diff --git a/mlir/include/mlir/Dialect/StandardOps/IR/CMakeLists.txt b/mlir/include/mlir/Dialect/StandardOps/IR/CMakeLists.txt
--- a/mlir/include/mlir/Dialect/StandardOps/IR/CMakeLists.txt
+++ b/mlir/include/mlir/Dialect/StandardOps/IR/CMakeLists.txt
@@ -2,6 +2,7 @@
 mlir_tablegen(Ops.h.inc -gen-op-decls)
 mlir_tablegen(Ops.cpp.inc -gen-op-defs)
 mlir_tablegen(OpsDialect.h.inc -gen-dialect-decls)
+mlir_tablegen(OpsDialect.cpp.inc -gen-dialect-defs)
 mlir_tablegen(OpsEnums.h.inc -gen-enum-decls)
 mlir_tablegen(OpsEnums.cpp.inc -gen-enum-defs)
 add_public_tablegen_target(MLIRStandardOpsIncGen)
diff --git a/mlir/include/mlir/IR/CMakeLists.txt b/mlir/include/mlir/IR/CMakeLists.txt
--- a/mlir/include/mlir/IR/CMakeLists.txt
+++ b/mlir/include/mlir/IR/CMakeLists.txt
@@ -9,6 +9,7 @@
 
 set(LLVM_TARGET_DEFINITIONS BuiltinDialect.td)
 mlir_tablegen(BuiltinDialect.h.inc -gen-dialect-decls)
+mlir_tablegen(BuiltinDialect.cpp.inc -gen-dialect-defs)
 add_public_tablegen_target(MLIRBuiltinDialectIncGen)
 
 set(LLVM_TARGET_DEFINITIONS BuiltinLocationAttributes.td)
diff --git a/mlir/include/mlir/IR/OpBase.td b/mlir/include/mlir/IR/OpBase.td
--- a/mlir/include/mlir/IR/OpBase.td
+++ b/mlir/include/mlir/IR/OpBase.td
@@ -267,6 +267,10 @@
   // If this dialect overrides the hook for materializing constants.
   bit hasConstantMaterializer = 0;
 
+  // If this dialect provides its own destructor definition (true) vs having
+  // one generated (false).
+  bit hasExplicitDestructor = 0;
+
   // If this dialect overrides the hook for verifying operation attributes.
   bit hasOperationAttrVerify = 0;
 
diff --git a/mlir/include/mlir/TableGen/Dialect.h b/mlir/include/mlir/TableGen/Dialect.h
--- a/mlir/include/mlir/TableGen/Dialect.h
+++ b/mlir/include/mlir/TableGen/Dialect.h
@@ -54,9 +54,13 @@
   /// Returns true if this dialect has a canonicalizer.
   bool hasCanonicalizer() const;
 
-  // Returns true if this dialect has a constant materializer.
+  /// Returns true if this dialect has a constant materializer.
   bool hasConstantMaterializer() const;
 
+  /// Returns true if the destructor definition is provided explicitly or
+  /// false if a default should be generated.
+  bool hasExplicitDestructor() const;
+
   /// Returns true if this dialect has an operation attribute verifier.
   bool hasOperationAttrVerify() const;
 
diff --git a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
--- a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
+++ b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
@@ -28,6 +28,8 @@
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/raw_ostream.h"
 
+#include "mlir/Dialect/StandardOps/IR/OpsDialect.cpp.inc"
+
 // Pull in all enum type definitions and utility function declarations.
 #include "mlir/Dialect/StandardOps/IR/OpsEnums.cpp.inc"
 
diff --git a/mlir/lib/IR/BuiltinDialect.cpp b/mlir/lib/IR/BuiltinDialect.cpp
--- a/mlir/lib/IR/BuiltinDialect.cpp
+++ b/mlir/lib/IR/BuiltinDialect.cpp
@@ -27,6 +27,8 @@
 // Builtin Dialect
 //===----------------------------------------------------------------------===//
 
+#include "mlir/IR/BuiltinDialect.cpp.inc"
+
 namespace {
 struct BuiltinOpAsmDialectInterface : public OpAsmDialectInterface {
   using OpAsmDialectInterface::OpAsmDialectInterface;
diff --git a/mlir/lib/TableGen/Dialect.cpp b/mlir/lib/TableGen/Dialect.cpp
--- a/mlir/lib/TableGen/Dialect.cpp
+++ b/mlir/lib/TableGen/Dialect.cpp
@@ -69,6 +69,10 @@
   return def->getValueAsBit("hasConstantMaterializer");
 }
 
+bool Dialect::hasExplicitDestructor() const {
+  return def->getValueAsBit("hasExplicitDestructor");
+}
+
 bool Dialect::hasOperationAttrVerify() const {
   return def->getValueAsBit("hasOperationAttrVerify");
 }
diff --git a/mlir/test/lib/Dialect/Test/CMakeLists.txt b/mlir/test/lib/Dialect/Test/CMakeLists.txt
--- a/mlir/test/lib/Dialect/Test/CMakeLists.txt
+++ b/mlir/test/lib/Dialect/Test/CMakeLists.txt
@@ -28,6 +28,7 @@
 mlir_tablegen(TestOps.h.inc -gen-op-decls)
 mlir_tablegen(TestOps.cpp.inc -gen-op-defs)
 mlir_tablegen(TestOpsDialect.h.inc -gen-dialect-decls -dialect=test)
+mlir_tablegen(TestOpsDialect.cpp.inc -gen-dialect-defs -dialect=test)
 mlir_tablegen(TestOpEnums.h.inc -gen-enum-decls)
 mlir_tablegen(TestOpEnums.cpp.inc -gen-enum-defs)
 mlir_tablegen(TestOpStructs.h.inc -gen-struct-attr-decls)
diff --git a/mlir/test/lib/Dialect/Test/TestDialect.cpp b/mlir/test/lib/Dialect/Test/TestDialect.cpp
--- a/mlir/test/lib/Dialect/Test/TestDialect.cpp
+++ b/mlir/test/lib/Dialect/Test/TestDialect.cpp
@@ -26,6 +26,8 @@
 using namespace mlir;
 using namespace mlir::test;
 
+#include "TestOpsDialect.cpp.inc"
+
 void mlir::test::registerTestDialect(DialectRegistry &registry) {
   registry.insert<TestDialect>();
 }
diff --git a/mlir/test/lib/Dialect/Test/TestOps.td b/mlir/test/lib/Dialect/Test/TestOps.td
--- a/mlir/test/lib/Dialect/Test/TestOps.td
+++ b/mlir/test/lib/Dialect/Test/TestOps.td
@@ -31,6 +31,7 @@
   let hasRegionArgAttrVerify = 1;
   let hasRegionResultAttrVerify = 1;
   let hasOperationInterfaceFallback = 1;
+  let hasExplicitDestructor = 1;
   let dependentDialects = ["::mlir::DLTIDialect"];
 
   let extraClassDeclaration = [{
@@ -47,8 +48,6 @@
       getParseOperationHook(StringRef opName) const override;
     LogicalResult printOperation(Operation *op,
                                  OpAsmPrinter &printer) const override;
-
-    ~TestDialect();
   private:
     // Storage for a custom fallback interface.
     void *fallbackEffectOpInterfaces;
diff --git a/mlir/tools/mlir-tblgen/DialectGen.cpp b/mlir/tools/mlir-tblgen/DialectGen.cpp
--- a/mlir/tools/mlir-tblgen/DialectGen.cpp
+++ b/mlir/tools/mlir-tblgen/DialectGen.cpp
@@ -17,6 +17,7 @@
 #include "mlir/TableGen/OpClass.h"
 #include "mlir/TableGen/Operator.h"
 #include "mlir/TableGen/Trait.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CommandLine.h"
@@ -54,6 +55,29 @@
           DialectFilterIterator(records.end(), records.end(), filterFn)};
 }
 
+static Optional<Dialect>
+findSelectedDialect(ArrayRef<const llvm::Record *> dialectDefs) {
+  // Select the dialect to gen for.
+  if (dialectDefs.size() == 1 && selectedDialect.getNumOccurrences() == 0) {
+    return Dialect(dialectDefs.front());
+  }
+
+  if (selectedDialect.getNumOccurrences() == 0) {
+    llvm::errs() << "when more than 1 dialect is present, one must be selected "
+                    "via '-dialect'\n";
+    return llvm::None;
+  }
+
+  auto dialectIt = llvm::find_if(dialectDefs, [](const llvm::Record *def) {
+    return Dialect(def).getName() == selectedDialect;
+  });
+  if (dialectIt == dialectDefs.end()) {
+    llvm::errs() << "selected dialect with '-dialect' does not exist\n";
+    return llvm::None;
+  }
+  return Dialect(*dialectIt);
+}
+
 //===----------------------------------------------------------------------===//
 // GEN: Dialect declarations
 //===----------------------------------------------------------------------===//
@@ -72,9 +96,11 @@
     {2}
     initialize();
   }
+
   void initialize();
   friend class ::mlir::MLIRContext;
 public:
+  ~{0}() override;
   static constexpr ::llvm::StringLiteral getDialectNamespace() {
     return ::llvm::StringLiteral("{1}");
   }
@@ -210,34 +236,52 @@
                              raw_ostream &os) {
   emitSourceFileHeader("Dialect Declarations", os);
 
-  auto defs = recordKeeper.getAllDerivedDefinitions("Dialect");
-  if (defs.empty())
+  auto dialectDefs = recordKeeper.getAllDerivedDefinitions("Dialect");
+  if (dialectDefs.empty())
     return false;
 
-  // Select the dialect to gen for.
-  const llvm::Record *dialectDef = nullptr;
-  if (defs.size() == 1 && selectedDialect.getNumOccurrences() == 0) {
-    dialectDef = defs.front();
-  } else if (selectedDialect.getNumOccurrences() == 0) {
-    llvm::errs() << "when more than 1 dialect is present, one must be selected "
-                    "via '-dialect'";
+  Optional<Dialect> dialect = findSelectedDialect(dialectDefs);
+  if (!dialect)
     return true;
-  } else {
-    auto dialectIt = llvm::find_if(defs, [](const llvm::Record *def) {
-      return Dialect(def).getName() == selectedDialect;
-    });
-    if (dialectIt == defs.end()) {
-      llvm::errs() << "selected dialect with '-dialect' does not exist";
-      return true;
-    }
-    dialectDef = *dialectIt;
-  }
-
   auto attrDefs = recordKeeper.getAllDerivedDefinitions("DialectAttr");
   auto typeDefs = recordKeeper.getAllDerivedDefinitions("DialectType");
-  Dialect dialect(dialectDef);
-  emitDialectDecl(dialect, filterForDialect<Attribute>(attrDefs, dialect),
-                  filterForDialect<Type>(typeDefs, dialect), os);
+  emitDialectDecl(*dialect, filterForDialect<Attribute>(attrDefs, *dialect),
+                  filterForDialect<Type>(typeDefs, *dialect), os);
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+// GEN: Dialect definitions
+//===----------------------------------------------------------------------===//
+
+/// The code block to generate a default desturctor definition.
+///
+/// {0}: The name of the dialect class.
+static const char *const dialectDestructorStr = R"(
+{0}::~{0}() = default;
+
+)";
+
+static void emitDialectDef(Dialect &dialect, raw_ostream &os) {
+  // Emit all nested namespaces.
+  NamespaceEmitter nsEmitter(os, dialect);
+
+  if (!dialect.hasExplicitDestructor())
+    os << llvm::formatv(dialectDestructorStr, dialect.getCppClassName());
+}
+
+static bool emitDialectDefs(const llvm::RecordKeeper &recordKeeper,
+                            raw_ostream &os) {
+  emitSourceFileHeader("Dialect Definitions", os);
+
+  auto dialectDefs = recordKeeper.getAllDerivedDefinitions("Dialect");
+  if (dialectDefs.empty())
+    return false;
+
+  Optional<Dialect> dialect = findSelectedDialect(dialectDefs);
+  if (!dialect)
+    return true;
+  emitDialectDef(*dialect, os);
   return false;
 }
 
@@ -250,3 +294,9 @@
                     [](const llvm::RecordKeeper &records, raw_ostream &os) {
                       return emitDialectDecls(records, os);
                     });
+
+static mlir::GenRegistration
+    genDialectDefs("gen-dialect-defs", "Generate dialect definitions",
+                   [](const llvm::RecordKeeper &records, raw_ostream &os) {
+                     return emitDialectDefs(records, os);
+                   });