[CFE] Serialize language version

Change-Id: I6ea448df722a7e1e51c31f06d42bfbe743855a45
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/111725
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>

pkg/kernel/binary.md

@@ -139,7 +139,7 @@ type CanonicalName {
 
 type ComponentFile {
   UInt32 magic = 0x90ABCDEF;
-  UInt32 formatVersion = 26;
+  UInt32 formatVersion = 27;
   List<String> problemsAsJson; // Described in problems.md.
   Library[] libraries;
   UriSource sourceMap;

pkg/kernel/lib/binary/ast_from_binary.dart

@@ -820,6 +820,15 @@ class BinaryBuilder {
     int flags = readByte();
     bool isExternal = (flags & Library.ExternalFlag) != 0;
     _isReadingLibraryImplementation = !isExternal;
+
+    // TODO(jensj): Eventually, language version should always be set.
+    int languageVersionMajor = readUInt();
+    int languageVersionMinor = readUInt();
+    if (languageVersionMajor == 0 || languageVersionMinor == 0) {
+      languageVersionMajor = null;
+      languageVersionMinor = null;
+    }
+
     var canonicalName = readCanonicalNameReference();
     Reference reference = canonicalName.getReference();
     Library library = reference.node;
@@ -842,6 +851,8 @@ class BinaryBuilder {
 
     if (shouldWriteData) {
       library.flags = flags;
+      library.languageVersionMajor = languageVersionMajor;
+      library.languageVersionMinor = languageVersionMinor;
       library.name = name;
       library.fileUri = fileUri;
       library.problemsAsJson = problemsAsJson;

pkg/kernel/lib/binary/ast_to_binary.dart

@@ -912,6 +912,11 @@ class BinaryPrinter implements Visitor<void>, BinarySink {
     insideExternalLibrary = node.isExternal;
     libraryOffsets.add(getBufferOffset());
     writeByte(node.flags);
+
+    // TODO(jensj): Eventually, language version should always be set.
+    writeUInt30(node.languageVersionMajor ?? 0);
+    writeUInt30(node.languageVersionMinor ?? 0);
+
     writeNonNullCanonicalNameReference(getCanonicalNameOfLibrary(node));
     writeStringReference(node.name ?? '');
     writeUriReference(node.fileUri);

pkg/kernel/lib/binary/tag.dart

@@ -150,7 +150,7 @@ class Tag {
   /// Internal version of kernel binary format.
   /// Bump it when making incompatible changes in kernel binaries.
   /// Keep in sync with runtime/vm/kernel_binary.h, pkg/kernel/binary.md.
-  static const int BinaryFormatVersion = 25;
+  static const int BinaryFormatVersion = 27;
 }
 
 abstract class ConstantTag {

runtime/vm/compiler/frontend/kernel_translation_helper.cc

@@ -1305,11 +1305,21 @@ void LibraryHelper::ReadUntilExcluding(Field field) {
 
   // Ordered with fall-through.
   switch (next_read_) {
+    // Note that this (up to canonical name) needs to be kept in sync with
+    // "library_canonical_name" (currently in "kernel_loader.h").
     case kFlags: {
       flags_ = helper_->ReadFlags();
       if (++next_read_ == field) return;
       FALL_THROUGH;
     }
+    case kLanguageVersion: {
+      if (binary_version_ >= 27) {
+        helper_->ReadUInt();  // Read major language version.
+        helper_->ReadUInt();  // Read minor language version.
+      }
+      if (++next_read_ == field) return;
+      FALL_THROUGH;
+    }
     case kCanonicalName:
       canonical_name_ =
           helper_->ReadCanonicalNameReference();  // read canonical_name.

runtime/vm/compiler/frontend/kernel_translation_helper.h

@@ -715,6 +715,7 @@ class LibraryHelper {
  public:
   enum Field {
     kFlags,
+    kLanguageVersion /* from binary version 27 */,
     kCanonicalName,
     kName,
     kSourceUriIndex,
@@ -739,8 +740,8 @@ class LibraryHelper {
     kSynthetic = 1 << 1,
   };
 
-  explicit LibraryHelper(KernelReaderHelper* helper)
-      : helper_(helper), next_read_(kFlags) {}
+  explicit LibraryHelper(KernelReaderHelper* helper, uint32_t binary_version)
+      : helper_(helper), binary_version_(binary_version), next_read_(kFlags) {}
 
   void ReadUntilIncluding(Field field) {
     ReadUntilExcluding(static_cast<Field>(static_cast<int>(field) + 1));
@@ -761,6 +762,7 @@ class LibraryHelper {
 
  private:
   KernelReaderHelper* helper_;
+  uint32_t binary_version_;
   intptr_t next_read_;
 
   DISALLOW_COPY_AND_ASSIGN(LibraryHelper);

runtime/vm/kernel_binary.h

@@ -20,7 +20,7 @@ static const uint32_t kMagicProgramFile = 0x90ABCDEFu;
 
 // Both version numbers are inclusive.
 static const uint32_t kMinSupportedKernelFormatVersion = 18;
-static const uint32_t kMaxSupportedKernelFormatVersion = 26;
+static const uint32_t kMaxSupportedKernelFormatVersion = 27;
 
 // Keep in sync with package:kernel/lib/binary/tag.dart
 #define KERNEL_TAG_LIST(V)                                                     \

runtime/vm/kernel_loader.cc

@@ -655,7 +655,7 @@ void KernelLoader::LoadNativeExtensionLibraries() {
     } else {
       helper_.SetOffset(library.kernel_offset());
 
-      LibraryHelper library_helper(&helper_);
+      LibraryHelper library_helper(&helper_, kernel_binary_version_);
       library_helper.ReadUntilExcluding(LibraryHelper::kAnnotations);
 
       const intptr_t annotation_count = helper_.ReadListLength();
@@ -925,7 +925,7 @@ void KernelLoader::walk_incremental_kernel(BitVector* modified_libs,
   for (intptr_t i = 0; i < length; i++) {
     intptr_t kernel_offset = library_offset(i);
     helper_.SetOffset(kernel_offset);
-    LibraryHelper library_helper(&helper_);
+    LibraryHelper library_helper(&helper_, kernel_binary_version_);
     library_helper.ReadUntilIncluding(LibraryHelper::kCanonicalName);
     lib = LookupLibraryOrNull(library_helper.canonical_name_);
     if (!lib.IsNull() && !lib.is_dart_scheme()) {
@@ -994,7 +994,7 @@ RawLibrary* KernelLoader::LoadLibrary(intptr_t index) {
   // offset.
   helper_.SetOffset(library_kernel_offset_);
 
-  LibraryHelper library_helper(&helper_);
+  LibraryHelper library_helper(&helper_, kernel_binary_version_);
   library_helper.ReadUntilIncluding(LibraryHelper::kCanonicalName);
   if (!FLAG_precompiled_mode && !I->should_load_vmservice()) {
     StringIndex lib_name_index =

runtime/vm/kernel_loader.h

@@ -288,7 +288,12 @@ class KernelLoader : public ValueObject {
     reader.set_offset(library_offset(index));
 
     // Start reading library.
+    // Note that this needs to be keep in sync with LibraryHelper.
     reader.ReadFlags();
+    if (program_->binary_version() >= 27) {
+      reader.ReadUInt();  // Read major language version.
+      reader.ReadUInt();  // Read minor language version.
+    }
     return reader.ReadCanonicalNameReference();
   }