Fix PR8565.

This moves most of the isUsed logic to the MCSymbol itself. With this we
get a bit more relaxed about allowing definitions after uses: uses that
don't evaluate their argument immediately (jmp foo) are accepted.

ddunbar, this was the smallest compromise I could think of that lets us
accept gcc (and clang!) assembly.

llvm-svn: 119144

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCSymbol.cpp b/llvm/lib/MC/MCSymbol.cpp
index 07751f72984..ebd3144a153 100644
--- a/llvm/lib/MC/MCSymbol.cpp
+++ b/llvm/lib/MC/MCSymbol.cpp
@@ -40,6 +40,7 @@ static bool NameNeedsQuoting(StringRef Str) {
 }
 
 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!");