[WebAssembly] Add codegen support for the import_field attribute

This adds the LLVM side of https://reviews.llvm.org/D57602 -- the
import_field attribute. See that patch for details.

Differential Revision: https://reviews.llvm.org/D57603

llvm-svn: 352931

1 files changed, 18 insertions, 4 deletions

diff --git a/llvm/include/llvm/MC/MCSymbolWasm.h b/llvm/include/llvm/MC/MCSymbolWasm.h
index e3f70cf6d1b..a39d1ce4b77 100644
--- a/llvm/include/llvm/MC/MCSymbolWasm.h
+++ b/llvm/include/llvm/MC/MCSymbolWasm.h
@@ -18,7 +18,8 @@ class MCSymbolWasm : public MCSymbol {
   bool IsWeak = false;
   bool IsHidden = false;
   bool IsComdat = false;
-  std::string ModuleName;
+  Optional<std::string> ImportModule;
+  Optional<std::string> ImportName;
   wasm::WasmSignature *Signature = nullptr;
   Optional<wasm::WasmGlobalType> GlobalType;
   Optional<wasm::WasmEventType> EventType;
@@ -31,7 +32,7 @@ public:
   // Use a module name of "env" for now, for compatibility with existing tools.
   // This is temporary, and may change, as the ABI is not yet stable.
   MCSymbolWasm(const StringMapEntry<bool> *Name, bool isTemporary)
-      : MCSymbol(SymbolKindWasm, Name, isTemporary), ModuleName("env") {}
+      : MCSymbol(SymbolKindWasm, Name, isTemporary) {}
   static bool classof(const MCSymbol *S) { return S->isWasm(); }
 
   const MCExpr *getSize() const { return SymbolSize; }
@@ -54,8 +55,21 @@ public:
   bool isComdat() const { return IsComdat; }
   void setComdat(bool isComdat) { IsComdat = isComdat; }
 
-  const StringRef getModuleName() const { return ModuleName; }
-  void setModuleName(StringRef Name) { ModuleName = Name; }
+  const StringRef getImportModule() const {
+      if (ImportModule.hasValue()) {
+          return ImportModule.getValue();
+      }
+      return "env";
+  }
+  void setImportModule(StringRef Name) { ImportModule = Name; }
+
+  const StringRef getImportName() const {
+      if (ImportName.hasValue()) {
+          return ImportName.getValue();
+      }
+      return getName();
+  }
+  void setImportName(StringRef Name) { ImportName = Name; }
 
   const wasm::WasmSignature *getSignature() const { return Signature; }
   void setSignature(wasm::WasmSignature *Sig) { Signature = Sig; }