[MC] Don't crash on division by zero.

[oota-llvm.git] / lib / MC / MCExpr.cpp

diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp
index a30ceecc952b459379f8cf7423a996406204914f..90cd7fa07b1a8942ba51c5ec3e90e255066c2672 100644 (file)
--- a/lib/MC/MCExpr.cpp
+++ b/lib/MC/MCExpr.cpp
@@ -739,7 +739,17 @@ bool MCExpr::evaluateAsRelocatableImpl(MCValue &Res, const MCAssembler *Asm,
     case MCBinaryExpr::AShr: Result = LHS >> RHS; break;
     case MCBinaryExpr::Add:  Result = LHS + RHS; break;
     case MCBinaryExpr::And:  Result = LHS & RHS; break;
-    case MCBinaryExpr::Div:  Result = LHS / RHS; break;
+    case MCBinaryExpr::Div: {
+      // Handle division by zero. gas just emits a warning and keeps going,
+      // we try to be stricter.
+      // FIXME: Currently the caller of this function has no way to understand
+      // we're bailing out because of 'division by zero'. Therefore, it will
+      // emit a 'expected relocatable expression' error. It would be nice to
+      // change this code to emit a better diagnostic.
+      if (RHS == 0)
+        return false;
+      Result = LHS / RHS; break;
+    }
     case MCBinaryExpr::EQ:   Result = LHS == RHS; break;
     case MCBinaryExpr::GT:   Result = LHS > RHS; break;
     case MCBinaryExpr::GTE:  Result = LHS >= RHS; break;