MC: Fix a crash on invalid, attempting to evaluate undefined symbols.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98464 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index 8d84f53..3bd6b1b 100644
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -195,10 +195,11 @@
if (!Sym.getValue()->EvaluateAsRelocatable(Res, Layout))
return false;
- // Absolutize symbol differences when we have a layout object and the
- // target requests it.
+ // Absolutize symbol differences between defined symbols when we have a
+ // layout object and the target requests it.
if (Layout && Res.getSymB() &&
- Layout->getAssembler().getBackend().hasAbsolutizedSet()) {
+ Layout->getAssembler().getBackend().hasAbsolutizedSet() &&
+ Res.getSymA()->isDefined() && Res.getSymB()->isDefined()) {
MCSymbolData &A = Layout->getAssembler().getSymbolData(*Res.getSymA());
MCSymbolData &B = Layout->getAssembler().getSymbolData(*Res.getSymB());
Res = MCValue::get(+ A.getFragment()->getAddress() + A.getOffset()