Index: llvm/trunk/include/llvm/BinaryFormat/Wasm.h
===================================================================
--- llvm/trunk/include/llvm/BinaryFormat/Wasm.h
+++ llvm/trunk/include/llvm/BinaryFormat/Wasm.h
@@ -184,7 +184,6 @@
 enum : unsigned {
   WASM_SYMBOL_INFO    = 0x2,
   WASM_DATA_SIZE      = 0x3,
-  WASM_DATA_ALIGNMENT = 0x4,
   WASM_SEGMENT_INFO   = 0x5,
 };
 
Index: llvm/trunk/test/ObjectYAML/wasm/linking_section.yaml
===================================================================
--- llvm/trunk/test/ObjectYAML/wasm/linking_section.yaml
+++ llvm/trunk/test/ObjectYAML/wasm/linking_section.yaml
@@ -0,0 +1,60 @@
+# RUN: yaml2obj %s | obj2yaml | FileCheck %s
+--- !WASM
+FileHeader:
+  Version:         0x00000001
+Sections:
+  - Type:            TYPE
+    Signatures:
+      - ReturnType:      I32
+        ParamTypes:
+          - I32
+  - Type:            IMPORT
+    Imports:
+      - Module:          foo
+        Field:           bar
+        Kind:            FUNCTION
+        SigIndex:        0
+  - Type:            DATA
+    Segments:
+      - MemoryIndex:      0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           4
+        Content:         '10001000'
+      - MemoryIndex:      0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           8
+        Content:         '11110000'
+  - Type:            CUSTOM
+    Name:            linking
+    DataSize:        999
+    SymbolInfo:
+      - Name:            bar
+        Flags:           1
+    SegmentInfo:
+      - Index:       0
+        Alignment:   4
+        Flags:       0
+        Name:        mydata
+      - Index:       1
+        Alignment:   2
+        Flags:       1
+        Name:        moredata
+...
+# CHECK:       - Type:            CUSTOM
+# CHECK-NEXT:    Name:            linking
+# CHECK-NEXT:    DataSize:        999
+# CHECK-NEXT:    SymbolInfo:
+# CHECK-NEXT:      - Name:            bar
+# CHECK-NEXT:        Flags:           1
+# CHECK-NEXT:    SegmentInfo:
+# CHECK-NEXT:      - Index:           0
+# CHECK-NEXT:        Name:            mydata
+# CHECK-NEXT:        Alignment:       4
+# CHECK-NEXT:        Flags:           0
+# CHECK-NEXT:      - Index:           1
+# CHECK-NEXT:        Name:            moredata
+# CHECK-NEXT:        Alignment:       2
+# CHECK-NEXT:        Flags:           1
+# CHECK-NEXT: ...
Index: llvm/trunk/tools/yaml2obj/yaml2wasm.cpp
===================================================================
--- llvm/trunk/tools/yaml2obj/yaml2wasm.cpp
+++ llvm/trunk/tools/yaml2obj/yaml2wasm.cpp
@@ -156,7 +156,6 @@
     encodeULEB128(wasm::WASM_SEGMENT_INFO, OS);
     encodeULEB128(Section.SegmentInfos.size(), SubSection.GetStream());
     for (const WasmYAML::SegmentInfo &SegmentInfo : Section.SegmentInfos) {
-      encodeULEB128(SegmentInfo.Index, SubSection.GetStream());
       writeStringRef(SegmentInfo.Name, SubSection.GetStream());
       encodeULEB128(SegmentInfo.Alignment, SubSection.GetStream());
       encodeULEB128(SegmentInfo.Flags, SubSection.GetStream());