[mips] PR34083 - Wimplicit-fallthrough warning in MipsAsmParser.cpp

Assert that a binary expression is actually a binary expression,
rather than potientially incorrectly attempting to handle it as a
unary expression.

This resolves PR34083.

Thanks to Simonn Pilgrim for reporting the issue!

llvm-svn: 310460

1 files changed, 7 insertions, 6 deletions

diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index e12188e7060..8a5de0150ad 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -5439,12 +5439,13 @@ bool MipsAsmParser::isEvaluated(const MCExpr *Expr) {
     return true;
   case MCExpr::SymbolRef:
     return (cast<MCSymbolRefExpr>(Expr)->getKind() != MCSymbolRefExpr::VK_None);
-  case MCExpr::Binary:
-    if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr)) {
-      if (!isEvaluated(BE->getLHS()))
-        return false;
-      return isEvaluated(BE->getRHS());
-    }
+  case MCExpr::Binary: {
+    const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr);
+    assert(BE && "Binary expression is not a binary expression?");
+    if (!isEvaluated(BE->getLHS()))
+      return false;
+    return isEvaluated(BE->getRHS());
+  }
   case MCExpr::Unary:
     return isEvaluated(cast<MCUnaryExpr>(Expr)->getSubExpr());
   case MCExpr::Target: