Vendor import of llvm trunk r126079:

http://llvm.org/svn/llvm-project/llvm/trunk@126079

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/MC/MCSymbol.cpp b/lib/MC/MCSymbol.cpp
index 07751f7..1c71f26 100644
--- a/lib/MC/MCSymbol.cpp
+++ b/lib/MC/MCSymbol.cpp
@@ -39,7 +39,20 @@ static bool NameNeedsQuoting(StringRef Str) {
   return false;
 }
 
+const MCSymbol &MCSymbol::AliasedSymbol() const {
+  const MCSymbol *S = this;
+  while (S->isVariable()) {
+    const MCExpr *Value = S->getVariableValue();
+    if (Value->getKind() != MCExpr::SymbolRef)
+      return *S;
+    const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
+    S = &Ref->getSymbol();
+  }
+  return *S;
+}
+
 void MCSymbol::setVariableValue(const MCExpr *Value) {
+  assert(!IsUsed && "Cannot set a variable that has already been used.");
   assert(Value && "Invalid variable value!");
   assert((isUndefined() || (isAbsolute() && isa<MCConstantExpr>(Value))) &&
          "Invalid redefinition!");