diff --git a/BUILD.gn b/BUILD.gn
index a5b3291..156cb69 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -373,6 +373,7 @@
     "src/inspector/scalar.h",
     "src/namer.cc",
     "src/namer.h",
+    "src/program.h",
     "src/reader/reader.cc",
     "src/reader/reader.h",
     "src/scope_stack.h",
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index c3aa242..cb0edaf 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -187,6 +187,7 @@
   inspector/scalar.h
   namer.cc
   namer.h
+  program.h
   reader/reader.cc
   reader/reader.h
   scope_stack.h
diff --git a/src/inspector/inspector.cc b/src/inspector/inspector.cc
index dbbaa21..5a3c9e8 100644
--- a/src/inspector/inspector.cc
+++ b/src/inspector/inspector.cc
@@ -45,6 +45,8 @@
 
 Inspector::Inspector(const ast::Module& module) : module_(module) {}
 
+Inspector::Inspector(const Program* program) : Inspector(program->module) {}
+
 Inspector::~Inspector() = default;
 
 std::vector<EntryPoint> Inspector::GetEntryPoints() {
diff --git a/src/inspector/inspector.h b/src/inspector/inspector.h
index 552dab6..662726c 100644
--- a/src/inspector/inspector.h
+++ b/src/inspector/inspector.h
@@ -25,6 +25,7 @@
 #include "src/ast/pipeline_stage.h"
 #include "src/inspector/entry_point.h"
 #include "src/inspector/scalar.h"
+#include "src/program.h"
 
 namespace tint {
 namespace inspector {
@@ -73,6 +74,12 @@
   /// Constructor
   /// @param module Shader module to extract information from.
   explicit Inspector(const ast::Module& module);
+
+  /// Constructor
+  /// @param program Shader program to extract information from.
+  explicit Inspector(const Program* program);
+
+  /// Destructor
   ~Inspector();
 
   /// @returns error messages from the Inspector
diff --git a/src/program.h b/src/program.h
new file mode 100644
index 0000000..31c7f03
--- /dev/null
+++ b/src/program.h
@@ -0,0 +1,41 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_PROGRAM_H_
+#define SRC_PROGRAM_H_
+
+#include <string>
+
+#include "src/ast/module.h"
+
+namespace tint {
+
+/// Program is (currently) a simple wrapper of to ast::Module.
+/// This wrapper is used as a stepping stone to having Dawn use tint::Program
+/// instead of tint::ast::Module.
+class Program {
+ public:
+  /// The wrapped module
+  ast::Module module;
+
+  /// @returns true if all required fields in the module are present.
+  bool IsValid() const { return module.IsValid(); }
+
+  /// @return a deep copy of this program
+  Program Clone() const { return Program{module.Clone()}; }
+};
+
+}  // namespace tint
+
+#endif  // SRC_PROGRAM_H_
diff --git a/src/reader/reader.h b/src/reader/reader.h
index 9c71184..a852dd0 100644
--- a/src/reader/reader.h
+++ b/src/reader/reader.h
@@ -21,6 +21,7 @@
 #include "src/ast/module.h"
 #include "src/diagnostic/diagnostic.h"
 #include "src/diagnostic/formatter.h"
+#include "src/program.h"
 
 namespace tint {
 namespace reader {
@@ -49,6 +50,9 @@
   /// @returns the module. The module in the parser will be reset after this.
   virtual ast::Module module() = 0;
 
+  /// @returns the program. The module in the parser will be reset after this.
+  Program program() { return Program{module()}; }
+
  protected:
   /// Constructor
   Reader();
diff --git a/src/transform/manager.h b/src/transform/manager.h
index b31a81c..8f838e4 100644
--- a/src/transform/manager.h
+++ b/src/transform/manager.h
@@ -46,6 +46,14 @@
   /// @returns the transformed module and diagnostics
   Output Run(ast::Module* module) override;
 
+  /// Runs the transform on `program`, returning the transformation result.
+  /// @note Users of Tint should register the transform with transform manager
+  /// and invoke its Run(), instead of directly calling the transform's Run().
+  /// Calling Run() directly does not perform program state cleanup operations.
+  /// @param program the source program to transform
+  /// @returns the transformation result
+  Output Run(Program* program) { return Run(&program->module); }
+
  private:
   std::vector<std::unique_ptr<Transform>> transforms_;
 };
diff --git a/src/transform/transform.cc b/src/transform/transform.cc
index 29f346b..9daa763 100644
--- a/src/transform/transform.cc
+++ b/src/transform/transform.cc
@@ -21,7 +21,27 @@
 namespace tint {
 namespace transform {
 
+Transform::Output::Output() = default;
+
+Transform::Output::Output(ast::Module&& mod) : program{std::move(mod)} {}
+
+Transform::Output::Output(ast::Module&& mod, diag::List&& d)
+    : program{std::move(mod)}, diagnostics(std::move(d)) {}
+
+Transform::Output::~Output() = default;
+
+Transform::Output::Output(Output&& rhs)
+    : program(std::move(rhs.program)),
+      diagnostics(std::move(rhs.diagnostics)) {}
+
+Transform::Output& Transform::Output::operator=(Output&& rhs) {
+  program = std::move(rhs.program);
+  diagnostics = std::move(rhs.diagnostics);
+  return *this;
+}
+
 Transform::Transform() = default;
+
 Transform::~Transform() = default;
 
 ast::Function* Transform::CloneWithStatementsAtStart(
diff --git a/src/transform/transform.h b/src/transform/transform.h
index 4684a21..9c359f2 100644
--- a/src/transform/transform.h
+++ b/src/transform/transform.h
@@ -21,6 +21,7 @@
 
 #include "src/ast/module.h"
 #include "src/diagnostic/diagnostic.h"
+#include "src/program.h"
 
 namespace tint {
 namespace transform {
@@ -35,10 +36,36 @@
 
   /// The return type of Run()
   struct Output {
-    /// The transformed module. May be empty on error.
-    ast::Module module;
+    /// Constructor
+    Output();
+
+    /// Constructor
+    /// @param module the module to move into this Output
+    explicit Output(ast::Module&& module);
+
+    /// Constructor
+    /// @param module the module to move into this Output
+    /// @param diags the list of diagnostics to move into this Output
+    Output(ast::Module&& module, diag::List&& diags);
+
+    /// Move constructor
+    /// @param output the output to move into this Output
+    Output(Output&& output);
+
+    /// Destructor
+    ~Output();
+
+    /// Move assignment operator
+    /// @param rhs the Output to move into this Output
+    /// @returns this Output
+    Output& operator=(Output&& rhs);
+
+    /// The transformed program. May be empty on error.
+    Program program;
     /// Diagnostics raised while running the Transform.
     diag::List diagnostics;
+    /// The transformed module. May be empty on error.
+    ast::Module& module{program.module};
   };
 
   /// Runs the transform on `module`, returning the transformation result.
@@ -49,6 +76,14 @@
   /// @returns the transformation result
   virtual Output Run(ast::Module* module) = 0;
 
+  /// Runs the transform on `program`, returning the transformation result.
+  /// @note Users of Tint should register the transform with transform manager
+  /// and invoke its Run(), instead of directly calling the transform's Run().
+  /// Calling Run() directly does not perform program state cleanup operations.
+  /// @param program the source program to transform
+  /// @returns the transformation result
+  Output Run(Program* program) { return Run(&program->module); }
+
  protected:
   /// Clones the function `in` adding `statements` to the beginning of the
   /// cloned function body.
diff --git a/src/type_determiner.cc b/src/type_determiner.cc
index 67875b5..6752c31 100644
--- a/src/type_determiner.cc
+++ b/src/type_determiner.cc
@@ -61,6 +61,9 @@
 
 TypeDeterminer::TypeDeterminer(ast::Module* mod) : mod_(mod) {}
 
+TypeDeterminer::TypeDeterminer(Program* program)
+    : TypeDeterminer(&program->module) {}
+
 TypeDeterminer::~TypeDeterminer() = default;
 
 void TypeDeterminer::set_error(const Source& src, const std::string& msg) {
diff --git a/src/type_determiner.h b/src/type_determiner.h
index f2aa2ba..3c38d6c 100644
--- a/src/type_determiner.h
+++ b/src/type_determiner.h
@@ -20,6 +20,7 @@
 #include <vector>
 
 #include "src/ast/module.h"
+#include "src/program.h"
 #include "src/scope_stack.h"
 #include "src/type/storage_texture_type.h"
 
@@ -45,6 +46,12 @@
   /// Constructor
   /// @param mod the module to update with typing information
   explicit TypeDeterminer(ast::Module* mod);
+
+  /// Constructor
+  /// @param program the module to update with typing information
+  explicit TypeDeterminer(Program* program);
+
+  /// Destructor
   ~TypeDeterminer();
 
   /// @returns error messages from the type determiner
diff --git a/src/validator/validator.h b/src/validator/validator.h
index 8b8f9a9..9d3fbc7 100644
--- a/src/validator/validator.h
+++ b/src/validator/validator.h
@@ -24,6 +24,7 @@
 #include "src/ast/statement.h"
 #include "src/diagnostic/diagnostic.h"
 #include "src/diagnostic/formatter.h"
+#include "src/program.h"
 
 namespace tint {
 
@@ -39,6 +40,11 @@
   /// @returns true if the validation was successful
   bool Validate(const ast::Module* module);
 
+  /// Runs the validator
+  /// @param program the program to validate
+  /// @returns true if the validation was successful
+  bool Validate(const Program* program) { return Validate(&program->module); }
+
   /// @returns error messages from the validator
   std::string error() {
     diag::Formatter formatter{{false, false, false, false}};
diff --git a/src/writer/hlsl/generator.cc b/src/writer/hlsl/generator.cc
index d521533..90d78c6 100644
--- a/src/writer/hlsl/generator.cc
+++ b/src/writer/hlsl/generator.cc
@@ -21,16 +21,13 @@
 namespace hlsl {
 
 Generator::Generator(ast::Module module)
-    : Text(std::move(module)),
+    : module_(std::move(module)),
       impl_(std::make_unique<GeneratorImpl>(&module_)) {}
 
-Generator::~Generator() = default;
+Generator::Generator(Program* program)
+    : impl_(std::make_unique<GeneratorImpl>(&program->module)) {}
 
-void Generator::Reset() {
-  set_error("");
-  out_ = std::ostringstream();
-  impl_ = std::make_unique<GeneratorImpl>(&module_);
-}
+Generator::~Generator() = default;
 
 bool Generator::Generate() {
   auto ret = impl_->Generate(out_);
diff --git a/src/writer/hlsl/generator.h b/src/writer/hlsl/generator.h
index 83f6d27..1c3b58c 100644
--- a/src/writer/hlsl/generator.h
+++ b/src/writer/hlsl/generator.h
@@ -19,6 +19,7 @@
 #include <sstream>
 #include <string>
 
+#include "src/program.h"
 #include "src/writer/hlsl/generator_impl.h"
 #include "src/writer/text.h"
 
@@ -32,10 +33,13 @@
   /// Constructor
   /// @param module the module to convert
   explicit Generator(ast::Module module);
-  ~Generator() override;
 
-  /// Resets the generator
-  void Reset() override;
+  /// Constructor
+  /// @param program the program to convert
+  explicit Generator(Program* program);
+
+  /// Destructor
+  ~Generator() override;
 
   /// Generates the result data
   /// @returns true on successful generation; false otherwise
@@ -55,6 +59,7 @@
   std::string error() const;
 
  private:
+  ast::Module module_;
   std::ostringstream out_;
   std::unique_ptr<GeneratorImpl> impl_;
 };
diff --git a/src/writer/hlsl/generator_impl.h b/src/writer/hlsl/generator_impl.h
index 433c3a1..834fd7c 100644
--- a/src/writer/hlsl/generator_impl.h
+++ b/src/writer/hlsl/generator_impl.h
@@ -74,9 +74,6 @@
   /// @returns the error
   std::string error() const { return error_; }
 
-  /// Resets the generator
-  void Reset();
-
   /// @param out the output stream
   /// @returns true on successful generation; false otherwise
   bool Generate(std::ostream& out);
diff --git a/src/writer/msl/generator.cc b/src/writer/msl/generator.cc
index 46fa073..5c6428c 100644
--- a/src/writer/msl/generator.cc
+++ b/src/writer/msl/generator.cc
@@ -21,15 +21,13 @@
 namespace msl {
 
 Generator::Generator(ast::Module module)
-    : Text(std::move(module)),
+    : module_(std::move(module)),
       impl_(std::make_unique<GeneratorImpl>(&module_)) {}
 
-Generator::~Generator() = default;
+Generator::Generator(Program* program)
+    : impl_(std::make_unique<GeneratorImpl>(&program->module)) {}
 
-void Generator::Reset() {
-  set_error("");
-  impl_ = std::make_unique<GeneratorImpl>(&module_);
-}
+Generator::~Generator() = default;
 
 bool Generator::Generate() {
   auto ret = impl_->Generate();
diff --git a/src/writer/msl/generator.h b/src/writer/msl/generator.h
index d0a9de2..7586a5a 100644
--- a/src/writer/msl/generator.h
+++ b/src/writer/msl/generator.h
@@ -18,6 +18,7 @@
 #include <memory>
 #include <string>
 
+#include "src/program.h"
 #include "src/writer/msl/generator_impl.h"
 #include "src/writer/text.h"
 
@@ -31,10 +32,13 @@
   /// Constructor
   /// @param module the module to convert
   explicit Generator(ast::Module module);
-  ~Generator() override;
 
-  /// Resets the generator
-  void Reset() override;
+  /// Constructor
+  /// @param program the program to convert
+  explicit Generator(Program* program);
+
+  /// Destructor
+  ~Generator() override;
 
   /// Generates the result data
   /// @returns true on successful generation; false otherwise
@@ -54,6 +58,7 @@
   std::string error() const;
 
  private:
+  ast::Module module_;
   std::unique_ptr<GeneratorImpl> impl_;
 };
 
diff --git a/src/writer/spirv/generator.cc b/src/writer/spirv/generator.cc
index c28cb13..ba367c5 100644
--- a/src/writer/spirv/generator.cc
+++ b/src/writer/spirv/generator.cc
@@ -21,16 +21,15 @@
 namespace spirv {
 
 Generator::Generator(ast::Module module)
-    : writer::Writer(std::move(module)),
+    : module_(std::move(module)),
       builder_(std::make_unique<Builder>(&module_)),
       writer_(std::make_unique<BinaryWriter>()) {}
 
-Generator::~Generator() = default;
+Generator::Generator(Program* program)
+    : builder_(std::make_unique<Builder>(&program->module)),
+      writer_(std::make_unique<BinaryWriter>()) {}
 
-void Generator::Reset() {
-  builder_ = std::make_unique<Builder>(&module_);
-  writer_ = std::make_unique<BinaryWriter>();
-}
+Generator::~Generator() = default;
 
 bool Generator::Generate() {
   if (!builder_->Build()) {
diff --git a/src/writer/spirv/generator.h b/src/writer/spirv/generator.h
index f5968b2..82bff48 100644
--- a/src/writer/spirv/generator.h
+++ b/src/writer/spirv/generator.h
@@ -20,6 +20,7 @@
 #include <vector>
 
 #include "src/ast/module.h"
+#include "src/program.h"
 #include "src/writer/spirv/binary_writer.h"
 #include "src/writer/spirv/builder.h"
 #include "src/writer/writer.h"
@@ -34,10 +35,13 @@
   /// Constructor
   /// @param module the module to convert
   explicit Generator(ast::Module module);
-  ~Generator() override;
 
-  /// Resets the generator
-  void Reset() override;
+  /// Constructor
+  /// @param program the program to convert
+  explicit Generator(Program* program);
+
+  /// Destructor
+  ~Generator() override;
 
   /// Generates the result data
   /// @returns true on successful generation; false otherwise
@@ -54,6 +58,7 @@
   const std::vector<uint32_t>& result() const { return writer_->result(); }
 
  private:
+  ast::Module module_;
   std::unique_ptr<Builder> builder_;
   std::unique_ptr<BinaryWriter> writer_;
 };
diff --git a/src/writer/text.cc b/src/writer/text.cc
index 319f32e..28fcd9d 100644
--- a/src/writer/text.cc
+++ b/src/writer/text.cc
@@ -19,8 +19,6 @@
 namespace tint {
 namespace writer {
 
-Text::Text(ast::Module module) : Writer(std::move(module)) {}
-
 Text::~Text() = default;
 
 }  // namespace writer
diff --git a/src/writer/text.h b/src/writer/text.h
index 7e4fffc..625e8e0 100644
--- a/src/writer/text.h
+++ b/src/writer/text.h
@@ -25,9 +25,6 @@
 /// Class to generate text source
 class Text : public Writer {
  public:
-  /// Constructor
-  /// @param module the module to convert
-  explicit Text(ast::Module module);
   ~Text() override;
 
   /// @returns the result data
diff --git a/src/writer/wgsl/generator.cc b/src/writer/wgsl/generator.cc
index e9d0a9b..368b5ef 100644
--- a/src/writer/wgsl/generator.cc
+++ b/src/writer/wgsl/generator.cc
@@ -21,15 +21,13 @@
 namespace wgsl {
 
 Generator::Generator(ast::Module module)
-    : Text(std::move(module)),
+    : module_(std::move(module)),
       impl_(std::make_unique<GeneratorImpl>(&module_)) {}
 
-Generator::~Generator() = default;
+Generator::Generator(Program* program)
+    : impl_(std::make_unique<GeneratorImpl>(&program->module)) {}
 
-void Generator::Reset() {
-  set_error("");
-  impl_ = std::make_unique<GeneratorImpl>(&module_);
-}
+Generator::~Generator() = default;
 
 bool Generator::Generate() {
   auto ret = impl_->Generate();
diff --git a/src/writer/wgsl/generator.h b/src/writer/wgsl/generator.h
index 2d3a234..3ed31ec 100644
--- a/src/writer/wgsl/generator.h
+++ b/src/writer/wgsl/generator.h
@@ -18,6 +18,7 @@
 #include <memory>
 #include <string>
 
+#include "src/program.h"
 #include "src/writer/text.h"
 #include "src/writer/wgsl/generator_impl.h"
 
@@ -31,10 +32,13 @@
   /// Constructor
   /// @param module the module to convert
   explicit Generator(ast::Module module);
-  ~Generator() override;
 
-  /// Resets the generator
-  void Reset() override;
+  /// Constructor
+  /// @param program the program to convert
+  explicit Generator(Program* program);
+
+  /// Destructor
+  ~Generator() override;
 
   /// Generates the result data
   /// @returns true on successful generation; false otherwise
@@ -54,6 +58,7 @@
   std::string error() const;
 
  private:
+  ast::Module module_;
   std::unique_ptr<GeneratorImpl> impl_;
 };
 
diff --git a/src/writer/writer.cc b/src/writer/writer.cc
index 545ed3b..7499c3c 100644
--- a/src/writer/writer.cc
+++ b/src/writer/writer.cc
@@ -19,8 +19,6 @@
 namespace tint {
 namespace writer {
 
-Writer::Writer(ast::Module module) : module_(std::move(module)) {}
-
 Writer::~Writer() = default;
 
 }  // namespace writer
diff --git a/src/writer/writer.h b/src/writer/writer.h
index b38657b..7aa7a97 100644
--- a/src/writer/writer.h
+++ b/src/writer/writer.h
@@ -31,11 +31,6 @@
   /// @returns the writer error string
   const std::string& error() const { return error_; }
 
-  /// Resets the generator
-  //! @cond Doxygen_Suppress
-  virtual void Reset() = 0;
-  //! @endcond
-
   /// Converts the module into the desired format
   /// @returns true on success; false on failure
   virtual bool Generate() = 0;
@@ -48,18 +43,12 @@
                                   const std::string& name) = 0;
 
  protected:
-  /// Constructor
-  /// @param module the tint module to convert
-  explicit Writer(ast::Module module);
-
   /// Sets the error string
   /// @param msg the error message
   void set_error(const std::string& msg) { error_ = msg; }
 
   /// An error message, if an error was encountered
   std::string error_;
-  /// The module being converted
-  ast::Module module_;
 };
 
 }  // namespace writer