[WebAssembly] Add version to object file metadata

Summary: See https://github.com/WebAssembly/tool-conventions/issues/54

Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D46069

llvm-svn: 330969

3 files changed, 11 insertions, 1 deletions

diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 0f8a42aacec..0e122708504 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -857,8 +857,9 @@ void WasmObjectWriter::writeLinkingMetaDataSection(
     const std::map<StringRef, std::vector<WasmComdatEntry>> &Comdats) {
   SectionBookkeeping Section;
   startCustomSection(Section, "linking");
-  SectionBookkeeping SubSection;
+  encodeULEB128(wasm::WasmMetadataVersion, getStream());
 
+  SectionBookkeeping SubSection;
   if (SymbolInfos.size() != 0) {
     startSection(SubSection, wasm::WASM_SYMBOL_TABLE);
     encodeULEB128(SymbolInfos.size(), getStream());
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index e6b7dded4e4..61db5d2468a 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -313,6 +313,14 @@ Error WasmObjectFile::parseLinkingSection(const uint8_t *Ptr,
         "Linking data must come after code section", object_error::parse_failed);
   }
 
+  LinkingData.Version = readVaruint32(Ptr);
+  if (LinkingData.Version != wasm::WasmMetadataVersion) {
+    return make_error<GenericBinaryError>(
+        "Unexpected metadata version: " + Twine(LinkingData.Version) +
+            " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")",
+        object_error::parse_failed);
+  }
+
   while (Ptr < End) {
     uint8_t Type = readUint8(Ptr);
     uint32_t Size = readVaruint32(Ptr);
diff --git a/llvm/lib/ObjectYAML/WasmYAML.cpp b/llvm/lib/ObjectYAML/WasmYAML.cpp
index 72df93b876a..ff75bfc7676 100644
--- a/llvm/lib/ObjectYAML/WasmYAML.cpp
+++ b/llvm/lib/ObjectYAML/WasmYAML.cpp
@@ -57,6 +57,7 @@ static void sectionMapping(IO &IO, WasmYAML::NameSection &Section) {
 static void sectionMapping(IO &IO, WasmYAML::LinkingSection &Section) {
   commonSectionMapping(IO, Section);
   IO.mapRequired("Name", Section.Name);
+  IO.mapRequired("Version", Section.Version);
   IO.mapOptional("SymbolTable", Section.SymbolTable);
   IO.mapOptional("SegmentInfo", Section.SegmentInfos);
   IO.mapOptional("InitFunctions", Section.InitFunctions);