9 files changed, 67 insertions, 4 deletions
diff --git a/src/binary-reader-logging.cc b/src/binary-reader-logging.cc
index 9a2d4e9a..2d0ada8f 100644
--- a/src/binary-reader-logging.cc
+++ b/src/binary-reader-logging.cc
@@ -602,6 +602,8 @@ DEFINE_INDEX_INDEX(OnInitExprGetGlobalExpr, "index", "global_index")
 DEFINE_BEGIN(BeginLinkingSection)
 DEFINE_INDEX(OnSymbolInfoCount)
 DEFINE_INDEX(OnStackGlobal)
+DEFINE_INDEX(OnDataSize)
+DEFINE_INDEX(OnDataAlignment)
 DEFINE_END(EndLinkingSection)
 
 DEFINE_BEGIN(BeginExceptionSection);
diff --git a/src/binary-reader-logging.h b/src/binary-reader-logging.h
index 6256bff2..6726ed07 100644
--- a/src/binary-reader-logging.h
+++ b/src/binary-reader-logging.h
@@ -235,6 +235,8 @@ class BinaryReaderLogging : public BinaryReaderDelegate {
   Result OnStackGlobal(Index stack_global) override;
   Result OnSymbolInfo(string_view name, uint32_t flags) override;
   Result OnSymbolInfoCount(Index count) override;
+  Result OnDataSize(uint32_t data_size) override;
+  Result OnDataAlignment(uint32_t data_alignment) override;
   Result EndLinkingSection() override;
 
   Result BeginExceptionSection(Offset size) override;
diff --git a/src/binary-reader-nop.h b/src/binary-reader-nop.h
index 2faa18cf..2fa57bbd 100644
--- a/src/binary-reader-nop.h
+++ b/src/binary-reader-nop.h
@@ -332,6 +332,10 @@ class BinaryReaderNop : public BinaryReaderDelegate {
   Result OnSymbolInfo(string_view name, uint32_t flags) override {
     return Result::Ok;
   }
+  Result OnDataSize(uint32_t data_size) override { return Result::Ok; }
+  Result OnDataAlignment(uint32_t data_alignment) override {
+    return Result::Ok;
+  }
   Result EndLinkingSection() override { return Result::Ok; }
 
   /* InitExpr - used by elem, data and global sections; these functions are
diff --git a/src/binary-reader-objdump.cc b/src/binary-reader-objdump.cc
index 5fe39adb..9baf3938 100644
--- a/src/binary-reader-objdump.cc
+++ b/src/binary-reader-objdump.cc
@@ -547,6 +547,8 @@ class BinaryReaderObjdump : public BinaryReaderObjdumpBase {
   Result OnStackGlobal(Index stack_global) override;
   Result OnSymbolInfoCount(Index count) override;
   Result OnSymbolInfo(string_view name, uint32_t flags) override;
+  Result OnDataSize(uint32_t data_size) override;
+  Result OnDataAlignment(uint32_t data_alignment) override;
 
   Result OnExceptionCount(Index count) override;
   Result OnExceptionType(Index index, TypeVector& sig)  override;
@@ -1110,6 +1112,16 @@ Result BinaryReaderObjdump::OnExceptionType(
   return Result::Ok;
 }
 
+Result BinaryReaderObjdump::OnDataSize(uint32_t data_size) {
+  PrintDetails("  - data size : %d\n", data_size);
+  return Result::Ok;
+}
+
+Result BinaryReaderObjdump::OnDataAlignment(uint32_t data_alignment) {
+  PrintDetails("  - data align: %d\n", data_alignment);
+  return Result::Ok;
+}
+
 }  // end anonymous namespace
 
 Result ReadBinaryObjdump(const uint8_t* data,
diff --git a/src/binary-reader.cc b/src/binary-reader.cc
index c484ae4d..a48cadcd 100644
--- a/src/binary-reader.cc
+++ b/src/binary-reader.cc
@@ -1264,6 +1264,18 @@ Result BinaryReader::ReadLinkingSection(Offset section_size) {
         }
         break;
       }
+      case LinkingEntryType::DataSize: {
+        uint32_t data_size;
+        CHECK_RESULT(ReadU32Leb128(&data_size, "data size"));
+        CALLBACK(OnDataSize, data_size);
+        break;
+      }
+      case LinkingEntryType::DataAlignment: {
+        uint32_t data_alignment;
+        CHECK_RESULT(ReadU32Leb128(&data_alignment, "data alignment"));
+        CALLBACK(OnDataAlignment, data_alignment);
+        break;
+      }
       default:
         /* unknown subsection, skip it */
         state_.offset = subsection_end;
diff --git a/src/binary-reader.h b/src/binary-reader.h
index b96ecb8a..0494ffd3 100644
--- a/src/binary-reader.h
+++ b/src/binary-reader.h
@@ -283,6 +283,8 @@ class BinaryReaderDelegate {
   virtual Result OnStackGlobal(Index stack_global) = 0;
   virtual Result OnSymbolInfoCount(Index count) = 0;
   virtual Result OnSymbolInfo(string_view name, uint32_t flags) = 0;
+  virtual Result OnDataSize(uint32_t data_size) = 0;
+  virtual Result OnDataAlignment(uint32_t data_alignment) = 0;
   virtual Result EndLinkingSection() = 0;
 
   /* Exception section */
diff --git a/src/binary-writer.cc b/src/binary-writer.cc
index 7be8ecb8..8627e377 100644
--- a/src/binary-writer.cc
+++ b/src/binary-writer.cc
@@ -1033,7 +1033,6 @@ Result BinaryWriter::WriteModule(const Module* module) {
     }
   }
 
-
   return stream_.result();
 }
 
diff --git a/src/common.h b/src/common.h
index 2b14c242..76722cba 100644
--- a/src/common.h
+++ b/src/common.h
@@ -225,6 +225,8 @@ struct Reloc {
 enum class LinkingEntryType {
   StackPointer = 1,
   SymbolInfo = 2,
+  DataSize = 3,
+  DataAlignment = 4,
 };
 
 enum class SymbolBinding {
diff --git a/src/tools/wasm-link.cc b/src/tools/wasm-link.cc
index f00b9603..b8758f85 100644
--- a/src/tools/wasm-link.cc
+++ b/src/tools/wasm-link.cc
@@ -218,6 +218,7 @@ class Linker {
   void WriteDataSegment(const DataSegment& segment, Address offset);
   void WriteDataSection(const SectionPtrVector& sections, Index total_count);
   void WriteNamesSection();
+  void WriteLinkingSection(uint32_t data_size, uint32_t data_alignment);
   void WriteRelocSection(BinarySection section_code,
                          const SectionPtrVector& sections);
   bool WriteCombinedSection(BinarySection section_code,
@@ -484,6 +485,30 @@ void Linker::WriteNamesSection() {
   FixupSize(fixup_section);
 }
 
+void Linker::WriteLinkingSection(uint32_t data_size, uint32_t data_alignment) {
+  stream_.WriteU8Enum(BinarySection::Custom, "section code");
+  auto fixup = WriteUnknownSize();
+
+  WriteStr(&stream_, "linking", "linking section name");
+
+  {
+    WriteU32Leb128Enum(&stream_, LinkingEntryType::DataSize, "subsection code");
+    auto fixup_subsection = WriteUnknownSize();
+    WriteU32Leb128(&stream_, data_size, "data size");
+    FixupSize(fixup_subsection);
+  }
+
+  {
+    WriteU32Leb128Enum(&stream_, LinkingEntryType::DataAlignment,
+                       "subsection code");
+    auto fixup_subsection = WriteUnknownSize();
+    WriteU32Leb128(&stream_, data_alignment, "data alignment");
+    FixupSize(fixup_subsection);
+  }
+
+  FixupSize(fixup);
+}
+
 void Linker::WriteRelocSection(BinarySection section_code,
                                const SectionPtrVector& sections) {
   Index total_relocs = 0;
@@ -723,9 +748,12 @@ void Linker::WriteBinary() {
 
   WriteNamesSection();
 
-  // Generate a new set of reloction sections.
-  for (size_t i = FIRST_KNOWN_SECTION; i < kBinarySectionCount; i++) {
-    WriteRelocSection(static_cast<BinarySection>(i), sections[i]);
+  /* Generate a new set of reloction sections */
+  if (s_relocatable) {
+    WriteLinkingSection(0, 0);
+    for (size_t i = FIRST_KNOWN_SECTION; i < kBinarySectionCount; i++) {
+      WriteRelocSection(static_cast<BinarySection>(i), sections[i]);
+    }
   }
 }