[WebAssembly] Attach a name to globals similarly to function naming

This allows LLD to print the name for an InputGlobal when encountering
an error.

Differential Revision: https://reviews.llvm.org/D44033

llvm-svn: 326691

2 files changed, 10 insertions, 3 deletions

diff --git a/llvm/include/llvm/BinaryFormat/Wasm.h b/llvm/include/llvm/BinaryFormat/Wasm.h
index b35ad7253bb..893eab8925a 100644
--- a/llvm/include/llvm/BinaryFormat/Wasm.h
+++ b/llvm/include/llvm/BinaryFormat/Wasm.h
@@ -74,6 +74,7 @@ struct WasmGlobal {
   uint32_t Index;
   WasmGlobalType Type;
   WasmInitExpr InitExpr;
+  StringRef Name; // from the "linking" or "names" section
 };
 
 struct WasmImport {
@@ -99,7 +100,7 @@ struct WasmFunction {
   ArrayRef<uint8_t> Body;
   uint32_t CodeSectionOffset;
   uint32_t Size;
-  StringRef Name; // from the "names" section
+  StringRef Name; // from the "linking" or "names" section
   StringRef Comdat; // from the "comdat info" section
 };
 
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 491a4cf70ab..23f25ea9aed 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -403,7 +403,7 @@ Error WasmObjectFile::parseLinkingSectionSymtab(const uint8_t *&Ptr,
         Info.Name = readString(Ptr);
         unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions;
         FunctionType = &Signatures[FunctionTypes[FuncIndex]];
-        auto &Function = Functions[FuncIndex];
+        wasm::WasmFunction &Function = Functions[FuncIndex];
         if (Function.Name.empty()) {
           // Use the symbol's name to set a name for the Function, but only if
           // one hasn't already been set.
@@ -425,7 +425,13 @@ Error WasmObjectFile::parseLinkingSectionSymtab(const uint8_t *&Ptr,
       if (IsDefined) {
         Info.Name = readString(Ptr);
         unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals;
-        GlobalType = &Globals[GlobalIndex].Type;
+        wasm::WasmGlobal &Global = Globals[GlobalIndex];
+        GlobalType = &Global.Type;
+        if (Global.Name.empty()) {
+          // Use the symbol's name to set a name for the Global, but only if
+          // one hasn't already been set.
+          Global.Name = Info.Name;
+        }
       } else {
         wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex];
         Info.Name = Import.Field;