Reland: [WebAssembly] Add __start_/_stop_ symbols for data sections

This is a reland of rL361235.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41565

Differential Revision: https://reviews.llvm.org/D61876

llvm-svn: 361476

1 files changed, 11 insertions, 0 deletions

diff --git a/lld/wasm/SymbolTable.cpp b/lld/wasm/SymbolTable.cpp
index 1a16b6390ba..ce1aa5132ba 100644
--- a/lld/wasm/SymbolTable.cpp
+++ b/lld/wasm/SymbolTable.cpp
@@ -198,6 +198,17 @@ DefinedFunction *SymbolTable::addSyntheticFunction(StringRef Name,
                                         Flags, nullptr, Function);
 }
 
+DefinedData *SymbolTable::addOptionalDataSymbol(StringRef Name, uint32_t Value,
+                                                uint32_t Flags) {
+  Symbol *S = find(Name);
+  if (!S || S->isDefined())
+    return nullptr;
+  LLVM_DEBUG(dbgs() << "addOptionalDataSymbol: " << Name << "\n");
+  auto *rtn = replaceSymbol<DefinedData>(S, Name, Flags);
+  rtn->setVirtualAddress(Value);
+  return rtn;
+}
+
 DefinedData *SymbolTable::addSyntheticDataSymbol(StringRef Name,
                                                  uint32_t Flags) {
   LLVM_DEBUG(dbgs() << "addSyntheticDataSymbol: " << Name << "\n");