Relax address updates in the eh_frame section.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122591 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCAssembler.h

@@ -52,6 +52,7 @@ public:
     FT_Inst,
     FT_Org,
     FT_Dwarf,
+    FT_DwarfFrame,
     FT_LEB
   };
 
@@ -369,7 +370,7 @@ class MCDwarfLineAddrFragment : public MCFragment {
 
 public:
   MCDwarfLineAddrFragment(int64_t _LineDelta, const MCExpr &_AddrDelta,
-                      MCSectionData *SD = 0)
+                      MCSectionData *SD)
     : MCFragment(FT_Dwarf, SD),
       LineDelta(_LineDelta), AddrDelta(&_AddrDelta) { Contents.push_back(0); }
 
@@ -391,6 +392,34 @@ public:
   static bool classof(const MCDwarfLineAddrFragment *) { return true; }
 };
 
+class MCDwarfCallFrameFragment : public MCFragment {
+  /// AddrDelta - The expression for the difference of the two symbols that
+  /// make up the address delta between two .cfi_* dwarf directives.
+  const MCExpr *AddrDelta;
+
+  SmallString<8> Contents;
+
+public:
+  MCDwarfCallFrameFragment(const MCExpr &_AddrDelta,  MCSectionData *SD)
+    : MCFragment(FT_DwarfFrame, SD),
+      AddrDelta(&_AddrDelta) { Contents.push_back(0); }
+
+  /// @name Accessors
+  /// @{
+
+  const MCExpr &getAddrDelta() const { return *AddrDelta; }
+
+  SmallString<8> &getContents() { return Contents; }
+  const SmallString<8> &getContents() const { return Contents; }
+
+  /// @}
+
+  static bool classof(const MCFragment *F) {
+    return F->getKind() == MCFragment::FT_DwarfFrame;
+  }
+  static bool classof(const MCDwarfCallFrameFragment *) { return true; }
+};
+
 // FIXME: Should this be a separate class, or just merged into MCSection? Since
 // we anticipate the fast path being through an MCAssembler, the only reason to
 // keep it out is for API abstraction.
@@ -705,6 +734,8 @@ private:
   bool RelaxLEB(MCAsmLayout &Layout, MCLEBFragment &IF);
 
   bool RelaxDwarfLineAddr(MCAsmLayout &Layout, MCDwarfLineAddrFragment &DF);
+  bool RelaxDwarfCallFrameFragment(MCAsmLayout &Layout,
+                                   MCDwarfCallFrameFragment &DF);
 
   /// FinishLayout - Finalize a layout, including fragment lowering.
   void FinishLayout(MCAsmLayout &Layout);

include/llvm/MC/MCDwarf.h

@@ -25,6 +25,7 @@
 namespace llvm {
   class MachineMove;
   class MCContext;
+  class MCExpr;
   class MCSection;
   class MCSectionData;
   class MCStreamer;
@@ -245,6 +246,8 @@ namespace llvm {
     // This emits the frame info section.
     //
     static void Emit(MCStreamer &streamer);
+    static void EmitAdvanceLoc(MCStreamer &Streamer, uint64_t AddrDelta);
+    static void EncodeAdvanceLoc(uint64_t AddrDelta, raw_ostream &OS);
   };
 } // end namespace llvm
 

include/llvm/MC/MCObjectStreamer.h

@@ -71,6 +71,8 @@ public:
   virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
                                         const MCSymbol *LastLabel,
                                         const MCSymbol *Label);
+  virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
+                                         const MCSymbol *Label);
   virtual void Finish();
 
   /// @}

include/llvm/MC/MCStreamer.h

@@ -386,6 +386,10 @@ namespace llvm {
                                           const MCSymbol *LastLabel,
                                           const MCSymbol *Label) = 0;
 
+    virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
+                                           const MCSymbol *Label) {
+    }
+
     void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
                               int PointerSize);