llvm-mc/Mach-O: Support byte and fill value emission.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79652 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 246 insertions, 10 deletions

diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index b2a2415..a5739f2 100644
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -10,8 +10,11 @@
 #ifndef LLVM_MC_MCASSEMBLER_H
 #define LLVM_MC_MCASSEMBLER_H
 
+#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/ilist.h"
 #include "llvm/ADT/ilist_node.h"
+#include "llvm/MC/MCValue.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/DataTypes.h"
 
 namespace llvm {
@@ -25,7 +28,211 @@ class MCFragment : public ilist_node<MCFragment> {
   void operator=(const MCFragment&); // DO NOT IMPLEMENT
 
 public:
-  MCFragment(MCSectionData *SD = 0);
+  enum FragmentType {
+    FT_Data,
+    FT_Align,
+    FT_Fill,
+    FT_Org
+  };
+
+private:
+  FragmentType Kind;
+
+  /// @name Assembler Backend Data
+  /// @{
+  //
+  // FIXME: This could all be kept private to the assembler implementation.
+
+  /// FileOffset - The offset of this section in the object file. This is ~0
+  /// until initialized.
+  uint64_t FileOffset;
+
+  /// FileSize - The size of this section in the object file. This is ~0 until
+  /// initialized.
+  uint64_t FileSize;
+
+  /// @}
+
+protected:
+  MCFragment(FragmentType _Kind, MCSectionData *SD = 0);
+
+public:
+  // Only for sentinel.
+  MCFragment();
+  virtual ~MCFragment();
+
+  FragmentType getKind() const { return Kind; }
+
+  // FIXME: This should be abstract, fix sentinel.
+  virtual unsigned getMaxFileSize() const {
+    assert(0 && "Invalid getMaxFileSize call !");
+  };
+
+  /// @name Assembler Backend Support
+  /// @{
+  //
+  // FIXME: This could all be kept private to the assembler implementation.
+
+  unsigned getFileSize() const { 
+    assert(FileSize != ~UINT64_C(0) && "File size not set!");
+    return FileSize;
+  }
+  void setFileSize(uint64_t Value) {
+    assert(Value <= getMaxFileSize() && "Invalid file size!");
+    FileSize = Value;
+  }
+
+  uint64_t getFileOffset() const {
+    assert(FileOffset != ~UINT64_C(0) && "File offset not set!");
+    return FileOffset;
+  }
+  void setFileOffset(uint64_t Value) { FileOffset = Value; }
+
+  /// @}
+
+  static bool classof(const MCFragment *O) { return true; }
+};
+
+class MCDataFragment : public MCFragment {
+  SmallString<32> Contents;
+
+public:
+  MCDataFragment(MCSectionData *SD = 0) : MCFragment(FT_Data, SD) {}
+
+  /// @name Accessors
+  /// @{
+
+  unsigned getMaxFileSize() const {
+    return Contents.size();
+  }
+
+  SmallString<32> &getContents() { return Contents; }
+  const SmallString<32> &getContents() const { return Contents; }
+
+  /// @}
+
+  static bool classof(const MCFragment *F) { 
+    return F->getKind() == MCFragment::FT_Data; 
+  }
+  static bool classof(const MCDataFragment *) { return true; }
+};
+
+class MCAlignFragment : public MCFragment {
+  /// Alignment - The alignment to ensure, in bytes.
+  unsigned Alignment;
+
+  /// Value - Value to use for filling padding bytes.
+  int64_t Value;
+
+  /// ValueSize - The size of the integer (in bytes) of \arg Value.
+  unsigned ValueSize;
+
+  /// MaxBytesToEmit - The maximum number of bytes to emit; if the alignment
+  /// cannot be satisfied in this width then this fragment is ignored.
+  unsigned MaxBytesToEmit;
+
+public:
+  MCAlignFragment(unsigned _Alignment, int64_t _Value, unsigned _ValueSize,
+                  unsigned _MaxBytesToEmit, MCSectionData *SD = 0)
+    : MCFragment(FT_Align, SD), Alignment(_Alignment),
+      Value(_Value),ValueSize(_ValueSize),
+      MaxBytesToEmit(_MaxBytesToEmit) {}
+
+  /// @name Accessors
+  /// @{
+
+  unsigned getMaxFileSize() const {
+    return std::max(Alignment - 1, MaxBytesToEmit);
+  }
+
+  unsigned getAlignment() const { return Alignment; }
+  
+  int64_t getValue() const { return Value; }
+
+  unsigned getValueSize() const { return ValueSize; }
+
+  unsigned getMaxBytesToEmit() const { return MaxBytesToEmit; }
+
+  /// @}
+
+  static bool classof(const MCFragment *F) { 
+    return F->getKind() == MCFragment::FT_Align; 
+  }
+  static bool classof(const MCAlignFragment *) { return true; }
+};
+
+class MCFillFragment : public MCFragment {
+  /// Value - Value to use for filling bytes.
+  MCValue Value;
+
+  /// ValueSize - The size (in bytes) of \arg Value to use when filling.
+  unsigned ValueSize;
+
+  /// Count - The number of copies of \arg Value to insert.
+  uint64_t Count;
+
+public:
+  MCFillFragment(MCValue _Value, unsigned _ValueSize, uint64_t _Count,
+                 MCSectionData *SD = 0) 
+    : MCFragment(FT_Fill, SD),
+      Value(_Value), ValueSize(_ValueSize), Count(_Count) {}
+
+  /// @name Accessors
+  /// @{
+
+  unsigned getMaxFileSize() const {
+    return ValueSize * Count;
+  }
+
+  MCValue getValue() const { return Value; }
+  
+  unsigned getValueSize() const { return ValueSize; }
+
+  uint64_t getCount() const { return Count; }
+
+  /// @}
+
+  static bool classof(const MCFragment *F) { 
+    return F->getKind() == MCFragment::FT_Fill; 
+  }
+  static bool classof(const MCFillFragment *) { return true; }
+};
+
+class MCOrgFragment : public MCFragment {
+  /// Offset - The offset this fragment should start at.
+  MCValue Offset;
+
+  /// Value - Value to use for filling bytes.  
+  int64_t Value;
+
+  /// ValueSize - The size (in bytes) of \arg Value to use when filling.
+  unsigned ValueSize;
+
+public:
+  MCOrgFragment(MCValue _Offset, int64_t _Value, unsigned _ValueSize,
+                MCSectionData *SD = 0)
+    : MCFragment(FT_Org, SD),
+      Offset(_Offset), Value(_Value), ValueSize(_ValueSize) {}
+  /// @name Accessors
+  /// @{
+
+  unsigned getMaxFileSize() const {
+    // FIXME
+    return 0;
+  }
+
+  MCValue getOffset() const { return Offset; }
+  
+  int64_t getValue() const { return Value; }
+  
+  unsigned getValueSize() const { return ValueSize; }
+
+  /// @}
+
+  static bool classof(const MCFragment *F) { 
+    return F->getKind() == MCFragment::FT_Org; 
+  }
+  static bool classof(const MCOrgFragment *) { return true; }
 };
 
 // FIXME: Should this be a separate class, or just merged into MCSection? Since
@@ -38,6 +245,9 @@ class MCSectionData : public ilist_node<MCSectionData> {
 public:
   typedef iplist<MCFragment> FragmentListType;
 
+  typedef FragmentListType::const_iterator const_iterator;
+  typedef FragmentListType::iterator iterator;
+
 private:
   iplist<MCFragment> Fragments;
   const MCSection &Section;
@@ -50,10 +260,12 @@ private:
   //
   // FIXME: This could all be kept private to the assembler implementation.
 
-  /// FileOffset - The offset of this section in the object file.
+  /// FileOffset - The offset of this section in the object file. This is ~0
+  /// until initialized.
   uint64_t FileOffset;
 
-  /// FileSize - The size of this section in the object file.
+  /// FileSize - The size of this section in the object file. This is ~0 until
+  /// initialized.
   uint64_t FileSize;
 
   /// @}
@@ -63,26 +275,44 @@ public:
   MCSectionData();
   MCSectionData(const MCSection &Section, MCAssembler *A = 0);
 
-  const FragmentListType &getFragmentList() const { return Fragments; }
-  FragmentListType &getFragmentList() { return Fragments; }
-
   const MCSection &getSection() const { return Section; }
 
   unsigned getAlignment() const { return Alignment; }
   void setAlignment(unsigned Value) { Alignment = Value; }
 
+
+  /// @name Section List Access
+  /// @{
+
+  const FragmentListType &getFragmentList() const { return Fragments; }
+  FragmentListType &getFragmentList() { return Fragments; }
+
+  iterator begin() { return Fragments.begin(); }
+  const_iterator begin() const { return Fragments.begin(); }
+
+  iterator end() { return Fragments.end(); }
+  const_iterator end() const { return Fragments.end(); }
+
+  size_t size() const { return Fragments.size(); }
+
+  /// @}
   /// @name Assembler Backend Support
   /// @{
   //
   // FIXME: This could all be kept private to the assembler implementation.
 
-  unsigned getFileSize() const { return FileSize; }
+  unsigned getFileSize() const { 
+    assert(FileSize != ~UINT64_C(0) && "File size not set!");
+    return FileSize;
+  }
+  void setFileSize(uint64_t Value) { FileSize = Value; }
 
-  uint64_t getFileOffset() const { return FileOffset; }
+  uint64_t getFileOffset() const {
+    assert(FileOffset != ~UINT64_C(0) && "File offset not set!");
+    return FileOffset;
+  }
   void setFileOffset(uint64_t Value) { FileOffset = Value; }
 
-  void WriteFileData(raw_ostream &OS) const;
-
   /// @}
 };
 
@@ -101,6 +331,12 @@ private:
   
   iplist<MCSectionData> Sections;
 
+private:
+  /// LayoutSection - Assign offsets and sizes to the fragments in the section
+  /// \arg SD, and update the section size. The section file offset should
+  /// already have been computed.
+  void LayoutSection(MCSectionData &SD);
+
 public:
   /// Construct a new assembler instance.
   ///