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

6 files changed, 16 insertions, 10 deletions

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 9c447f171bb..265d73dde3a 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -175,7 +175,8 @@ public:
 
   void EmitBytes(StringRef Data) override;
 
-  void EmitValueImpl(const MCExpr *Value, unsigned Size) override;
+  void EmitValueImpl(const MCExpr *Value, unsigned Size,
+                     const SMLoc &Loc = SMLoc()) override;
   void EmitIntValue(uint64_t Value, unsigned Size) override;
 
   void EmitULEB128Value(const MCExpr *Value) override;
@@ -702,7 +703,8 @@ void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
   EmitValue(MCConstantExpr::Create(Value, getContext()), Size);
 }
 
-void MCAsmStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size) {
+void MCAsmStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
+                                  const SMLoc &Loc) {
   assert(Size <= 8 && "Invalid size");
   assert(getCurrentSection().first &&
          "Cannot emit contents before setting section!");
diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp
index 4242b626b3c..d42636e1803 100644
--- a/llvm/lib/MC/MCELFStreamer.cpp
+++ b/llvm/lib/MC/MCELFStreamer.cpp
@@ -275,11 +275,12 @@ void MCELFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
   EmitCommonSymbol(Symbol, Size, ByteAlignment);
 }
 
-void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size) {
+void MCELFStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
+                                  const SMLoc &Loc) {
   if (getCurrentSectionData()->isBundleLocked())
     report_fatal_error("Emitting values inside a locked bundle is forbidden");
   fixSymbolsInTLSFixups(Value);
-  MCObjectStreamer::EmitValueImpl(Value, Size);
+  MCObjectStreamer::EmitValueImpl(Value, Size, Loc);
 }
 
 void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
diff --git a/llvm/lib/MC/MCNullStreamer.cpp b/llvm/lib/MC/MCNullStreamer.cpp
index 2747090bd60..53f9548f68e 100644
--- a/llvm/lib/MC/MCNullStreamer.cpp
+++ b/llvm/lib/MC/MCNullStreamer.cpp
@@ -70,7 +70,8 @@ namespace {
                         uint64_t Size, unsigned ByteAlignment) override {}
     void EmitBytes(StringRef Data) override {}
 
-    void EmitValueImpl(const MCExpr *Value, unsigned Size) override {}
+    void EmitValueImpl(const MCExpr *Value, unsigned Size,
+                       const SMLoc &Loc = SMLoc()) override {}
     void EmitULEB128Value(const MCExpr *Value) override {}
     void EmitSLEB128Value(const MCExpr *Value) override {}
     void EmitGPRel32Value(const MCExpr *Value) override {}
diff --git a/llvm/lib/MC/MCObjectStreamer.cpp b/llvm/lib/MC/MCObjectStreamer.cpp
index 50f67c1c113..ea3f42574da 100644
--- a/llvm/lib/MC/MCObjectStreamer.cpp
+++ b/llvm/lib/MC/MCObjectStreamer.cpp
@@ -97,7 +97,8 @@ const MCExpr *MCObjectStreamer::AddValueSymbols(const MCExpr *Value) {
   return Value;
 }
 
-void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size) {
+void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
+                                     const SMLoc &Loc) {
   MCDataFragment *DF = getOrCreateDataFragment();
 
   MCLineEntry::Make(this, getCurrentSection().first);
@@ -110,7 +111,7 @@ void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size) {
   }
   DF->getFixups().push_back(
       MCFixup::Create(DF->getContents().size(), Value,
-                      MCFixup::getKindForSize(Size, false)));
+                      MCFixup::getKindForSize(Size, false), Loc));
   DF->getContents().resize(DF->getContents().size() + Size, 0);
 }
 
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 910a424ce84..345b59c6cea 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -2364,7 +2364,7 @@ bool AsmParser::parseDirectiveValue(unsigned Size) {
           return Error(ExprLoc, "literal value out of range for directive");
         getStreamer().EmitIntValue(IntValue, Size);
       } else
-        getStreamer().EmitValue(Value, Size);
+        getStreamer().EmitValue(Value, Size, ExprLoc);
 
       if (getLexer().is(AsmToken::EndOfStatement))
         break;
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index f85f7d3210c..50b6576766c 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -147,8 +147,9 @@ void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size) {
 }
 
 
-void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size) {
-  EmitValueImpl(Value, Size);
+void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
+                           const SMLoc &Loc) {
+  EmitValueImpl(Value, Size, Loc);
 }
 
 void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size) {