ARM64: initial backend import

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

diff --git a/include/llvm/MC/MCAsmLayout.h b/include/llvm/MC/MCAsmLayout.h
index d448625320cd99aa759b9dc2a1c2426e8de8288e..3058b7b48742db623837d325dd3736c17139ff12 100644 (file)
--- a/include/llvm/MC/MCAsmLayout.h
+++ b/include/llvm/MC/MCAsmLayout.h
@@ -10,25 +10,101 @@
 #ifndef LLVM_MC_MCASMLAYOUT_H
 #define LLVM_MC_MCASMLAYOUT_H
 
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+
 namespace llvm {
 class MCAssembler;
+class MCFragment;
+class MCSectionData;
+class MCSymbolData;
 
 /// Encapsulates the layout of an assembly file at a particular point in time.
 ///
-/// Assembly may requiring compute multiple layouts for a particular assembly
+/// Assembly may require computing multiple layouts for a particular assembly
 /// file as part of the relaxation process. This class encapsulates the layout
 /// at a single point in time in such a way that it is always possible to
-/// efficiently compute the exact addresses of any symbol in the assembly file,
+/// efficiently compute the exact address of any symbol in the assembly file,
 /// even during the relaxation process.
 class MCAsmLayout {
+public:
+  typedef llvm::SmallVectorImpl<MCSectionData*>::const_iterator const_iterator;
+  typedef llvm::SmallVectorImpl<MCSectionData*>::iterator iterator;
+
 private:
   MCAssembler &Assembler;
 
+  /// List of sections in layout order.
+  llvm::SmallVector<MCSectionData*, 16> SectionOrder;
+
+  /// The last fragment which was laid out, or 0 if nothing has been laid
+  /// out. Fragments are always laid out in order, so all fragments with a
+  /// lower ordinal will be valid.
+  mutable DenseMap<const MCSectionData*, MCFragment*> LastValidFragment;
+
+  /// \brief Make sure that the layout for the given fragment is valid, lazily
+  /// computing it if necessary.
+  void ensureValid(const MCFragment *F) const;
+
+  /// \brief Is the layout for this fragment valid?
+  bool isFragmentValid(const MCFragment *F) const;
+
+  /// \brief Compute the amount of padding required before this fragment to
+  /// obey bundling restrictions.
+  uint64_t computeBundlePadding(const MCFragment *F,
+                                uint64_t FOffset, uint64_t FSize);
+
 public:
-  MCAsmLayout(MCAssembler &_Assembler) : Assembler(_Assembler) {}
+  MCAsmLayout(MCAssembler &_Assembler);
 
   /// Get the assembler object this is a layout for.
-  MCAssembler &getAssembler() { return Assembler; }
+  MCAssembler &getAssembler() const { return Assembler; }
+
+  /// \brief Invalidate the fragments starting with F because it has been
+  /// resized. The fragment's size should have already been updated, but
+  /// its bundle padding will be recomputed.
+  void invalidateFragmentsFrom(MCFragment *F);
+
+  /// \brief Perform layout for a single fragment, assuming that the previous
+  /// fragment has already been laid out correctly, and the parent section has
+  /// been initialized.
+  void layoutFragment(MCFragment *Fragment);
+
+  /// @name Section Access (in layout order)
+  /// @{
+
+  llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() {
+    return SectionOrder;
+  }
+  const llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() const {
+    return SectionOrder;
+  }
+
+  /// @}
+  /// @name Fragment Layout Data
+  /// @{
+
+  /// \brief Get the offset of the given fragment inside its containing section.
+  uint64_t getFragmentOffset(const MCFragment *F) const;
+
+  /// @}
+  /// @name Utility Functions
+  /// @{
+
+  /// \brief Get the address space size of the given section, as it effects
+  /// layout. This may differ from the size reported by \see getSectionSize() by
+  /// not including section tail padding.
+  uint64_t getSectionAddressSize(const MCSectionData *SD) const;
+
+  /// \brief Get the data size of the given section, as emitted to the object
+  /// file. This may include additional padding, or be 0 for virtual sections.
+  uint64_t getSectionFileSize(const MCSectionData *SD) const;
+
+  /// \brief Get the offset of the given symbol, as computed in the current
+  /// layout.
+  uint64_t getSymbolOffset(const MCSymbolData *SD) const;
+
+  /// @}
 };
 
 } // end namespace llvm