Fix a crash with X86 Mach-O and a subtraction expression where both symbols are
undefined and produce an error message instead as this is a non-relocatable
expression with X86 Mach-O.
rdar://8920876
llvm-svn: 188218
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
index 64f005c..6eff224 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
@@ -175,6 +175,11 @@
if (A_Base == B_Base && A_Base)
report_fatal_error("unsupported relocation with identical base");
+ // A subtraction expression where both symbols are undefined is a
+ // non-relocatable expression.
+ if (A->isUndefined() && B->isUndefined())
+ report_fatal_error("unsupported relocation with subtraction expression");
+
Value += Writer->getSymbolAddress(&A_SD, Layout) -
(A_Base == NULL ? 0 : Writer->getSymbolAddress(A_Base, Layout));
Value -= Writer->getSymbolAddress(&B_SD, Layout) -