Added support for generate DWARF .debug_aranges sections automatically.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191052 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCELFStreamer.h

@@ -85,6 +85,8 @@ public:
 
   virtual void EmitValueToAlignment(unsigned, int64_t, unsigned, unsigned);
 
+  virtual void Flush();
+
   virtual void FinishImpl();
   /// @}
 

include/llvm/MC/MCStreamer.h

@@ -86,6 +86,10 @@ private:
 
   MCSymbol *LastSymbol;
 
+  // SymbolOrdering - Tracks an index to represent the order
+  // a symbol was emitted in. Zero means we did not emit that symbol.
+  DenseMap<const MCSymbol *, unsigned> SymbolOrdering;
+
   /// SectionStack - This is stack of current and previous section
   /// values saved by PushSection.
   SmallVector<std::pair<MCSectionSubPair, MCSectionSubPair>, 4> SectionStack;
@@ -185,6 +189,12 @@ public:
     return MCSectionSubPair();
   }
 
+  /// GetSymbolOrder - Returns an index to represent the order
+  /// a symbol was emitted in. (zero if we did not emit that symbol)
+  unsigned GetSymbolOrder(const MCSymbol *Sym) const {
+    return SymbolOrdering.lookup(Sym);
+  }
+
   /// ChangeSection - Update streamer for a new active section.
   ///
   /// This is called by PopSection and SwitchSection, if the current
@@ -264,6 +274,12 @@ public:
   /// InitToTextSection - Create a text section and switch the streamer to it.
   virtual void InitToTextSection() = 0;
 
+  /// AssignSection - Sets the symbol's section.
+  ///
+  /// Each emitted symbol will be tracked in the ordering table,
+  /// so we can sort on them later.
+  void AssignSection(MCSymbol *Symbol, const MCSection *Section);
+
   /// EmitLabel - Emit a label for @p Symbol into the current section.
   ///
   /// This corresponds to an assembler statement such as:
@@ -620,6 +636,9 @@ public:
   /// these methods there.
   virtual void EmitTCEntry(const MCSymbol &S);
 
+  /// Flush - Causes any cached state to be written out.
+  virtual void Flush() {}
+
   /// FinishImpl - Streamer specific finalization.
   virtual void FinishImpl() = 0;
   /// Finish - Finish emission of machine code.