From: Daniel Dunbar <daniel@zuster.org>
Date: Mon, 8 Mar 2010 21:10:39 +0000 (+0000)
Subject: MC/Mach-O: Error out instead of crashing on invalid scattered relocation expressions.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0ce6bd55c38b2e146b5ce887bae576ee538bb575;p=oota-llvm.git

MC/Mach-O: Error out instead of crashing on invalid scattered relocation expressions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97983 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 96227dbee50..3f40a6d6a4c 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -447,13 +447,22 @@ public:
     // See <reloc.h>.
     const MCSymbol *A = Target.getSymA();
     MCSymbolData *SD = SymbolMap.lookup(A);
+
+    if (!SD->getFragment())
+      llvm_report_error("symbol '" + A->getName() +
+                        "' can not be undefined in a subtraction expression");
+
     uint32_t Value = SD->getFragment()->getAddress() + SD->getOffset();
     uint32_t Value2 = 0;
 
     if (const MCSymbol *B = Target.getSymB()) {
-      Type = RIT_LocalDifference;
-
       MCSymbolData *SD = SymbolMap.lookup(B);
+
+      if (!SD->getFragment())
+        llvm_report_error("symbol '" + B->getName() +
+                          "' can not be undefined in a subtraction expression");
+
+      Type = RIT_LocalDifference;
       Value2 = SD->getFragment()->getAddress() + SD->getOffset();
     }