change MCContext to work on the doInitialization/doFinalization model

[oota-llvm.git] / include / llvm / MC / MCAsmBackend.h

diff --git a/include/llvm/MC/MCAsmBackend.h b/include/llvm/MC/MCAsmBackend.h
index 26d69f2d86026fba8920799b9fe06a29f99263f3..72ed1a317c55775daaf16f1593afaac77805fa72 100644 (file)
--- a/include/llvm/MC/MCAsmBackend.h
+++ b/include/llvm/MC/MCAsmBackend.h
@@ -12,32 +12,31 @@
 
 #include "llvm/MC/MCDirectives.h"
 #include "llvm/MC/MCFixup.h"
-#include "llvm/MC/MCFixupKindInfo.h"
 #include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorHandling.h"
 
 namespace llvm {
 class MCAsmLayout;
 class MCAssembler;
 class MCELFObjectTargetWriter;
-class MCFixup;
+struct MCFixupKindInfo;
 class MCFragment;
 class MCInst;
 class MCInstFragment;
 class MCObjectWriter;
 class MCSection;
 class MCValue;
-template<typename T>
-class SmallVectorImpl;
 class raw_ostream;
 
 /// MCAsmBackend - Generic interface to target specific assembler backends.
 class MCAsmBackend {
-  MCAsmBackend(const MCAsmBackend &);   // DO NOT IMPLEMENT
-  void operator=(const MCAsmBackend &);  // DO NOT IMPLEMENT
+  MCAsmBackend(const MCAsmBackend &) LLVM_DELETED_FUNCTION;
+  void operator=(const MCAsmBackend &) LLVM_DELETED_FUNCTION;
 protected: // Can only create subclasses.
   MCAsmBackend();
 
   unsigned HasReliableSymbolDifference : 1;
+  unsigned HasDataInCodeSupport : 1;
 
 public:
   virtual ~MCAsmBackend();
@@ -49,8 +48,8 @@ public:
   /// createELFObjectTargetWriter - Create a new ELFObjectTargetWriter to enable
   /// non-standard ELFObjectWriters.
   virtual  MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
-    assert(0 && "createELFObjectTargetWriter is not supported by asm backend");
-    return 0;
+    llvm_unreachable("createELFObjectTargetWriter is not supported by asm "
+                     "backend");
   }
 
   /// hasReliableSymbolDifference - Check whether this target implements
@@ -67,6 +66,12 @@ public:
     return HasReliableSymbolDifference;
   }
 
+  /// hasDataInCodeSupport - Check whether this target implements data-in-code
+  /// markers. If not, data region directives will be ignored.
+  bool hasDataInCodeSupport() const {
+    return HasDataInCodeSupport;
+  }
+
   /// doesSectionRequireSymbols - Check whether the given section requires that
   /// all symbols (even temporaries) have symbol table entries.
   virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
@@ -91,15 +96,17 @@ public:
   virtual const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const;
 
   /// processFixupValue - Target hook to adjust the literal value of a fixup
-  /// if necessary. The default does nothing.
+  /// if necessary. IsResolved signals whether the caller believes a relocation
+  /// is needed; the target can modify the value. The default does nothing.
   virtual void processFixupValue(const MCAssembler &Asm,
                                  const MCAsmLayout &Layout,
                                  const MCFixup &Fixup, const MCFragment *DF,
-                                 MCValue &Target, uint64_t &Value) {}
+                                 MCValue &Target, uint64_t &Value,
+                                 bool &IsResolved) {}
 
   /// @}
 
-  /// applyFixup - Apply the \arg Value for given \arg Fixup into the provided
+  /// applyFixup - Apply the \p Value for given \p Fixup into the provided
   /// data fragment, at the offset specified by the fixup and following the
   /// fixup kind as appropriate.
   virtual void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
@@ -126,13 +133,20 @@ public:
   /// RelaxInstruction - Relax the instruction in the given fragment to the next
   /// wider instruction.
   ///
-  /// \param Inst - The instruction to relax, which may be the same as the
+  /// \param Inst The instruction to relax, which may be the same as the
   /// output.
-  /// \parm Res [output] - On return, the relaxed instruction.
+  /// \param [out] Res On return, the relaxed instruction.
   virtual void relaxInstruction(const MCInst &Inst, MCInst &Res) const = 0;
 
   /// @}
 
+  /// getMinimumNopSize - Returns the minimum size of a nop in bytes on this
+  /// target. The assembler will use this to emit excess padding in situations
+  /// where the padding required for simple alignment would be less than the
+  /// minimum nop size.
+  ///
+  virtual unsigned getMinimumNopSize() const { return 1; }
+
   /// writeNopData - Write an (optimal) nop sequence of Count bytes to the given
   /// output. If the target cannot generate such a sequence, it should return an
   /// error.