[WebAssembly] Define WebAssembly-specific relocation codes.

Currently WebAssembly has two kinds of relocations; data addresses and
function addresses. This adds ELF relocations for them, as well as an
MC symbol kind to indicate which type of relocation is needed.

llvm-svn: 257416

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
index 6c1ef40b0cc..8d84901b3a2 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -70,6 +70,7 @@ private:
   void EmitConstantPool() override;
   void EmitFunctionBodyStart() override;
   void EmitInstruction(const MachineInstr *MI) override;
+  const MCExpr *lowerConstant(const Constant *CV) override;
   bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
                        unsigned AsmVariant, const char *ExtraCode,
                        raw_ostream &OS) override;
@@ -221,6 +222,14 @@ void WebAssemblyAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   }
 }
 
+const MCExpr *WebAssemblyAsmPrinter::lowerConstant(const Constant *CV) {
+  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
+    if (GV->getValueType()->isFunctionTy())
+      return MCSymbolRefExpr::create(
+          getSymbol(GV), MCSymbolRefExpr::VK_WebAssembly_FUNCTION, OutContext);
+  return AsmPrinter::lowerConstant(CV);
+}
+
 bool WebAssemblyAsmPrinter::PrintAsmOperand(const MachineInstr *MI,
                                             unsigned OpNo, unsigned AsmVariant,
                                             const char *ExtraCode,