ARM Fixups relative to thumb functions need to have the low bit of the value
set for interworking to work properly. rdar://8755956
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121778 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 319f04c..5bc477d 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -235,12 +235,15 @@
bool IsPCRel = Emitter.getFixupKindInfo(
Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
bool IsResolved = true;
+ bool IsThumb = false;
if (const MCSymbolRefExpr *A = Target.getSymA()) {
const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
if (Sym.isDefined())
Value += Layout.getSymbolOffset(&getSymbolData(Sym));
else
IsResolved = false;
+ if (isThumbFunc(&Sym))
+ IsThumb = true;
}
if (const MCSymbolRefExpr *B = Target.getSymB()) {
const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
@@ -263,6 +266,13 @@
Value -= Layout.getFragmentOffset(DF) + Fixup.getOffset();
}
+ // ARM fixups based from a thumb function address need to have the low
+ // bit set. The actual value is always at least 16-bit aligned, so the
+ // low bit is normally clear and available for use as an ISA flag for
+ // interworking.
+ if (IsThumb)
+ Value |= 1;
+
return IsResolved;
}