Add SPIR-V parser impl

The parser impl saves a copy of the SPIR-V binary.

Bug: tint:3
Change-Id: I5d61c87123c0bcb417d0c7004e0ef4e3c8fbb027
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/16642
Reviewed-by: dan sinclair <dsinclair@google.com>

src/CMakeLists.txt

@@ -189,8 +189,11 @@ set(TINT_LIB_SRCS
 
 if(TINT_BUILD_SPV_PARSER)
   list(APPEND TINT_LIB_SRCS
+    reader/spv/fail_stream.h
     reader/spv/parser.cc
     reader/spv/parser.h
+    reader/spv/parser_impl.cc
+    reader/spv/parser_impl.h
   )
 endif()
 

src/reader/spv/fail_stream.h

@@ -39,11 +39,11 @@ class FailStream {
 
   /// Converts to a boolean status. A true result indicates success,
   /// and a false result indicates failure.
-  /// @returns status
+  /// @returns the status
   operator bool() const { return *status_ptr_; }
   /// Returns the current status value.  This can be more readable
   /// the conversion operator.
-  /// @returns status
+  /// @returns the status
   bool status() const { return *status_ptr_; }
 
   /// Records failure.

src/reader/spv/parser.cc

@@ -14,23 +14,25 @@
 
 #include "src/reader/spv/parser.h"
 
-#include <utility>
+#include "src/reader/spv/parser_impl.h"
 
 namespace tint {
 namespace reader {
 namespace spv {
 
-Parser::Parser(const std::vector<uint32_t>&) : Reader() {}
+Parser::Parser(const std::vector<uint32_t>& spv_binary)
+    : Reader(), impl_(std::make_unique<ParserImpl>(spv_binary)) {}
 
 Parser::~Parser() = default;
 
 bool Parser::Parse() {
-  set_error("SPIR-V parsing is not supported yet");
+  const auto result = impl_->Parse();
-  return false;
+  set_error(impl_->error());
+  return result;
 }
 
 ast::Module Parser::module() {
-  return std::move(module_);
+  return impl_->module();
 }
 
 }  // namespace spv

src/reader/spv/parser.h

@@ -15,6 +15,8 @@
 #ifndef SRC_READER_SPV_PARSER_H_
 #define SRC_READER_SPV_PARSER_H_
 
+#include <cstdint>
+#include <memory>
 #include <vector>
 
 #include "src/reader/reader.h"
@@ -42,7 +44,7 @@ class Parser : public Reader {
   ast::Module module() override;
 
  private:
-  ast::Module module_;
+  std::unique_ptr<ParserImpl> impl_;
 };
 
 }  // namespace spv

src/reader/spv/parser_impl.cc

@@ -0,0 +1,45 @@
+// Copyright 2020 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.
+
+#include <cstring>
+
+#include "src/reader/spv/parser_impl.h"
+
+namespace tint {
+namespace reader {
+namespace spv {
+
+ParserImpl::ParserImpl(const std::vector<uint32_t>& spv_binary)
+    : Reader(), spv_binary_(spv_binary), fail_stream_(&success_, &errors_) {}
+
+ParserImpl::~ParserImpl() = default;
+
+bool ParserImpl::Parse() {
+  // Exit early if we've already failed.
+  if (success_) {
+    Fail() << "SPIR-V parsing is not supported yet";
+  }
+
+  return success_;
+}
+
+ast::Module ParserImpl::module() {
+  // TODO(dneto): Should we clear out spv_binary_ here, to reduce
+  // memory usage?
+  return std::move(ast_module_);
+}
+
+}  // namespace spv
+}  // namespace reader
+}  // namespace tint

src/reader/spv/parser_impl.h

@@ -0,0 +1,75 @@
+// Copyright 2020 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_READER_SPV_PARSER_IMPL_H_
+#define SRC_READER_SPV_PARSER_IMPL_H_
+
+#include <cstdint>
+#include <memory>
+#include <sstream>
+#include <vector>
+
+#include "src/reader/reader.h"
+#include "src/reader/spv/fail_stream.h"
+
+namespace tint {
+namespace reader {
+namespace spv {
+
+/// Parser implementation for SPIR-V.
+class ParserImpl : Reader {
+ public:
+  /// Creates a new parser
+  /// @param input the input data to parse
+  explicit ParserImpl(const std::vector<uint32_t>& input);
+  ~ParserImpl() override;
+
+  /// Run the parser
+  /// @returns true if the parse was successful, false otherwise.
+  bool Parse() override;
+
+  /// @returns the module. The module in the parser will be reset after this.
+  ast::Module module() override;
+
+  /// Logs failure, ands return a failure stream to accumulate diagnostic
+  /// messages. By convention, a failure should only be logged along with
+  /// a non-empty string diagnostic.
+  /// @returns the failure stream
+  FailStream& Fail() {
+    success_ = false;
+    return fail_stream_;
+  }
+
+  /// @returns the accumulated error string
+  const std::string error() { return errors_.str(); }
+
+ private:
+  // The SPIR-V binary we're parsing
+  std::vector<uint32_t> spv_binary_;
+
+  // The resulting module in Tint AST form.
+  ast::Module ast_module_;
+
+  // Is the parse successful?
+  bool success_ = true;
+  // Collector for diagnostic messages.
+  std::stringstream errors_;
+  FailStream fail_stream_;
+};
+
+}  // namespace spv
+}  // namespace reader
+}  // namespace tint
+
+#endif  // SRC_READER_SPV_PARSER_IMPL_H_