Change MCExpr::EvaluateAsRelocatableImpl of variables to return the original

variable if recursing fails to simplify it.

Factor AliasedSymbol to be a method of MCSymbol.

Update MCAssembler::EvaluateFixup to match the change in
EvaluateAsRelocatableImpl.

Remove the WeakRefExpr hack, as the object writer now sees the weakref with
no extra effort needed.

Nothing else is using MCTargetExpr, but keep it for now.

Now that the ELF writer sees relocations with aliases, handle

    .weak    foo2
foo2:
    .weak    bar2
    .set    bar2,foo2
    .quad    bar2

the same way gas does and produce a relocation with bar2.

llvm-svn: 119152

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCSymbol.cpp b/llvm/lib/MC/MCSymbol.cpp
index ebd3144a..1c71f26 100644
--- a/llvm/lib/MC/MCSymbol.cpp
+++ b/llvm/lib/MC/MCSymbol.cpp
@@ -39,6 +39,18 @@ 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!");