Fix the assembler to print a better relocatable expression error

diagnostic that includes location information.

Currently if one has this assembly:

	.quad (0x1234 + (4 * SOME_VALUE))

where SOME_VALUE is undefined ones gets the less than
useful error message with no location information:

% clang -c x.s
clang -cc1as: fatal error: error in backend: expected relocatable expression

With this fix one now gets a more useful error message
with location information:

% clang -c x.s 
x.s:5:8: error: expected relocatable expression
 .quad (0x1234 + (4 * SOME_VALUE))
       ^

To do this I plumbed the SMLoc through the MCObjectStreamer
EmitValue() and EmitValueImpl() interfaces so it could be used
when creating the MCFixup.

rdar://12391022

llvm-svn: 206906

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 5a01d261d47..5f706dfe894 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -531,7 +531,8 @@ public:
   /// This is one of the functions used to emit data into an ELF section, so the
   /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
   /// necessary.
-  void EmitValueImpl(const MCExpr *Value, unsigned Size) override {
+  void EmitValueImpl(const MCExpr *Value, unsigned Size,
+                     const SMLoc &Loc) override {
     EmitDataMappingSymbol();
     MCELFStreamer::EmitValueImpl(Value, Size);
   }