Refactor MCInstFragment and MCDataFragment to adhere to a common interface,

which removes code duplication and prepares the ground for future additions.

Full discussion:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121203/158233.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169626 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index 266e0c7f4842abf6137b23aa38d7c15df6b210e5..a308030ff6bd949c68d007c083520c1492e2ae9b 100644 (file)
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -102,7 +102,35 @@ public:
   void dump();
 };
 
-class MCDataFragment : public MCFragment {
+class MCEncodedFragment : public MCFragment {
+  virtual void anchor();
+public:
+  MCEncodedFragment(MCFragment::FragmentType FType, MCSectionData *SD = 0)
+    : MCFragment(FType, SD) {
+  }
+  virtual ~MCEncodedFragment();
+
+  typedef SmallVectorImpl<MCFixup>::const_iterator const_fixup_iterator;
+  typedef SmallVectorImpl<MCFixup>::iterator fixup_iterator;
+
+  virtual SmallString<32> &getContents() = 0;
+  virtual const SmallString<32> &getContents() const = 0;
+
+  virtual SmallVectorImpl<MCFixup> &getFixups() = 0;
+  virtual const SmallVectorImpl<MCFixup> &getFixups() const = 0;
+
+  virtual fixup_iterator fixup_begin() = 0;
+  virtual const_fixup_iterator fixup_begin() const  = 0;
+  virtual fixup_iterator fixup_end() = 0;
+  virtual const_fixup_iterator fixup_end() const = 0;
+
+  static bool classof(const MCFragment *F) {
+    MCFragment::FragmentType Kind = F->getKind();
+    return Kind == MCFragment::FT_Inst || Kind == MCFragment::FT_Data;
+  }
+};
+
+class MCDataFragment : public MCEncodedFragment {
   virtual void anchor();
   SmallString<32> Contents;
 
@@ -110,27 +138,19 @@ class MCDataFragment : public MCFragment {
   SmallVector<MCFixup, 4> Fixups;
 
 public:
-  typedef SmallVectorImpl<MCFixup>::const_iterator const_fixup_iterator;
-  typedef SmallVectorImpl<MCFixup>::iterator fixup_iterator;
-
-public:
-  MCDataFragment(MCSectionData *SD = 0) : MCFragment(FT_Data, SD) {}
-
-  /// @name Accessors
-  /// @{
+  MCDataFragment(MCSectionData *SD = 0)
+    : MCEncodedFragment(FT_Data, SD) {
+  }
 
   SmallString<32> &getContents() { return Contents; }
   const SmallString<32> &getContents() const { return Contents; }
 
-  /// @}
-  /// @name Fixup Access
-  /// @{
+  SmallVectorImpl<MCFixup> &getFixups() {
+    return Fixups;
+  }
 
-  void addFixup(MCFixup Fixup) {
-    // Enforce invariant that fixups are in offset order.
-    assert((Fixups.empty() || Fixup.getOffset() >= Fixups.back().getOffset()) &&
-           "Fixups must be added in order!");
-    Fixups.push_back(Fixup);
+  const SmallVectorImpl<MCFixup> &getFixups() const {
+    return Fixups;
   }
 
   fixup_iterator fixup_begin() { return Fixups.begin(); }
@@ -139,55 +159,42 @@ public:
   fixup_iterator fixup_end() {return Fixups.end();}
   const_fixup_iterator fixup_end() const {return Fixups.end();}
 
-  /// @}
-
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Data;
   }
 };
 
-// FIXME: This current incarnation of MCInstFragment doesn't make much sense, as
-// it is almost entirely a duplicate of MCDataFragment. If we decide to stick
-// with this approach (as opposed to making MCInstFragment a very light weight
-// object with just the MCInst and a code size, then we should just change
-// MCDataFragment to have an optional MCInst at its end.
-class MCInstFragment : public MCFragment {
+class MCInstFragment : public MCEncodedFragment {
   virtual void anchor();
 
   /// Inst - The instruction this is a fragment for.
   MCInst Inst;
 
-  /// Code - Binary data for the currently encoded instruction.
-  SmallString<8> Code;
+  /// Contents - Binary data for the currently encoded instruction.
+  SmallString<32> Contents;
 
   /// Fixups - The list of fixups in this fragment.
   SmallVector<MCFixup, 1> Fixups;
 
-public:
-  typedef SmallVectorImpl<MCFixup>::const_iterator const_fixup_iterator;
-  typedef SmallVectorImpl<MCFixup>::iterator fixup_iterator;
-
 public:
   MCInstFragment(const MCInst &_Inst, MCSectionData *SD = 0)
-    : MCFragment(FT_Inst, SD), Inst(_Inst) {
+    : MCEncodedFragment(FT_Inst, SD), Inst(_Inst) {
   }
 
-  /// @name Accessors
-  /// @{
-
-  SmallVectorImpl<char> &getCode() { return Code; }
-  const SmallVectorImpl<char> &getCode() const { return Code; }
+  SmallString<32> &getContents() { return Contents; }
+  const SmallString<32> &getContents() const { return Contents; }
 
-  unsigned getInstSize() const { return Code.size(); }
+  unsigned getInstSize() const { return Contents.size(); }
   const MCInst &getInst() const { return Inst; }
   void setInst(const MCInst& Value) { Inst = Value; }
 
-  /// @}
-  /// @name Fixup Access
-  /// @{
+  SmallVectorImpl<MCFixup> &getFixups() {
+    return Fixups;
+  }
 
-  SmallVectorImpl<MCFixup> &getFixups() { return Fixups; }
-  const SmallVectorImpl<MCFixup> &getFixups() const { return Fixups; }
+  const SmallVectorImpl<MCFixup> &getFixups() const {
+    return Fixups;
+  }
 
   fixup_iterator fixup_begin() { return Fixups.begin(); }
   const_fixup_iterator fixup_begin() const { return Fixups.begin(); }
@@ -195,8 +202,6 @@ public:
   fixup_iterator fixup_end() {return Fixups.end();}
   const_fixup_iterator fixup_end() const {return Fixups.end();}
 
-  /// @}
-
   static bool classof(const MCFragment *F) {
     return F->getKind() == MCFragment::FT_Inst;
   }

diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 5032e6fff6999dd70f5af653ebda1573d34c3bd8..b2136e553e29ac1807abc5b0f467e34597969579 100644 (file)
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -168,6 +168,11 @@ MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
 
 /* *** */
 
+MCEncodedFragment::~MCEncodedFragment() {
+}
+
+/* *** */
+
 MCSectionData::MCSectionData() : Section(0) {}
 
 MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
@@ -382,9 +387,16 @@ void MCAsmLayout::LayoutFragment(MCFragment *F) {
   LastValidFragment[F->getParent()] = F;
 }
 
-/// WriteFragmentData - Write the \p F data to the output file.
-static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
-                              const MCFragment &F) {
+/// \brief Write the contents of a fragment to the given object writer. Expects
+///        a MCEncodedFragment.
+static void writeFragmentContents(const MCFragment &F, MCObjectWriter *OW) {
+  MCEncodedFragment &EF = cast<MCEncodedFragment>(F);
+  OW->WriteBytes(EF.getContents().str());
+}
+
+/// \brief Write the fragment \p F to the output file.
+static void writeFragment(const MCAssembler &Asm, const MCAsmLayout &Layout,
+                          const MCFragment &F) {
   MCObjectWriter *OW = &Asm.getWriter();
   uint64_t Start = OW->getStream().tell();
   (void) Start;
@@ -433,13 +445,15 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
     break;
   }
 
-  case MCFragment::FT_Data: {
+  case MCFragment::FT_Data: 
     ++stats::EmittedDataFragments;
-    MCDataFragment &DF = cast<MCDataFragment>(F);
-    assert(FragmentSize == DF.getContents().size() && "Invalid size!");
-    OW->WriteBytes(DF.getContents().str());
+    writeFragmentContents(F, OW);
+    break;
+
+  case MCFragment::FT_Inst:
+    ++stats::EmittedInstFragments;
+    writeFragmentContents(F, OW);
     break;
-  }
 
   case MCFragment::FT_Fill: {
     MCFillFragment &FF = cast<MCFillFragment>(F);
@@ -458,13 +472,6 @@ static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
     break;
   }
 
-  case MCFragment::FT_Inst: {
-    ++stats::EmittedInstFragments;
-    MCInstFragment &IF = cast<MCInstFragment>(F);
-    OW->WriteBytes(StringRef(IF.getCode().begin(), IF.getCode().size()));
-    break;
-  }
-
   case MCFragment::FT_LEB: {
     MCLEBFragment &LF = cast<MCLEBFragment>(F);
     OW->WriteBytes(LF.getContents().str());
@@ -538,9 +545,9 @@ void MCAssembler::writeSectionData(const MCSectionData *SD,
   uint64_t Start = getWriter().getStream().tell();
   (void)Start;
 
-  for (MCSectionData::const_iterator it = SD->begin(),
-         ie = SD->end(); it != ie; ++it)
-    WriteFragmentData(*this, Layout, *it);
+  for (MCSectionData::const_iterator it = SD->begin(), ie = SD->end();
+       it != ie; ++it)
+    writeFragment(*this, Layout, *it);
 
   assert(getWriter().getStream().tell() - Start ==
          Layout.getSectionAddressSize(SD));
@@ -617,24 +624,14 @@ void MCAssembler::Finish() {
   for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
     for (MCSectionData::iterator it2 = it->begin(),
            ie2 = it->end(); it2 != ie2; ++it2) {
-      MCDataFragment *DF = dyn_cast<MCDataFragment>(it2);
-      if (DF) {
-        for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
-               ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
-          MCFixup &Fixup = *it3;
-          uint64_t FixedValue = handleFixup(Layout, *DF, Fixup);
-          getBackend().applyFixup(Fixup, DF->getContents().data(),
-                                  DF->getContents().size(), FixedValue);
-        }
-      }
-      MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
-      if (IF) {
-        for (MCInstFragment::fixup_iterator it3 = IF->fixup_begin(),
-               ie3 = IF->fixup_end(); it3 != ie3; ++it3) {
+      MCEncodedFragment *F = dyn_cast<MCEncodedFragment>(it2);
+      if (F) {
+        for (MCEncodedFragment::fixup_iterator it3 = F->fixup_begin(),
+             ie3 = F->fixup_end(); it3 != ie3; ++it3) {
           MCFixup &Fixup = *it3;
-          uint64_t FixedValue = handleFixup(Layout, *IF, Fixup);
-          getBackend().applyFixup(Fixup, IF->getCode().data(),
-                                  IF->getCode().size(), FixedValue);
+          uint64_t FixedValue = handleFixup(Layout, *F, Fixup);
+          getBackend().applyFixup(Fixup, F->getContents().data(),
+                                  F->getContents().size(), FixedValue);
         }
       }
     }
@@ -704,11 +701,8 @@ bool MCAssembler::relaxInstruction(MCAsmLayout &Layout,
 
   // Update the instruction fragment.
   IF.setInst(Relaxed);
-  IF.getCode() = Code;
-  IF.getFixups().clear();
-  // FIXME: Eliminate copy.
-  for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
-    IF.getFixups().push_back(Fixups[i]);
+  IF.getContents() = Code;
+  IF.getFixups() = Fixups;
 
   return true;
 }
@@ -977,6 +971,7 @@ void MCAssembler::dump() {
 #endif
 
 // anchors for MC*Fragment vtables
+void MCEncodedFragment::anchor() { }
 void MCDataFragment::anchor() { }
 void MCInstFragment::anchor() { }
 void MCAlignFragment::anchor() { }

diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index b1952bf175639c24ba0882072fb9970da85d13bd..8b9bdb14a073b2d332a6439eb3beaba352d32c0f 100644 (file)
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -345,7 +345,7 @@ void MCELFStreamer::EmitInstToData(const MCInst &Inst) {
   // Add the fixups and data.
   for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
     Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
-    DF->addFixup(Fixups[i]);
+    DF->getFixups().push_back(Fixups[i]);
   }
   DF->getContents().append(Code.begin(), Code.end());
 }

diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index cc6c853c7716fcf11800370d4bdc1e69cbfad15e..f279e74e389833424f1dcdd4bad09850b99d575f 100644 (file)
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -368,7 +368,7 @@ void MCMachOStreamer::EmitInstToData(const MCInst &Inst) {
   // Add the fixups and data.
   for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
     Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
-    DF->addFixup(Fixups[i]);
+    DF->getFixups().push_back(Fixups[i]);
   }
   DF->getContents().append(Code.begin(), Code.end());
 }

diff --git a/lib/MC/MCObjectStreamer.cpp b/lib/MC/MCObjectStreamer.cpp
index 08200eb8f0ca5929430c5c47ef6f685f9c747be5..c2171ffaa5e3e868b9423cf49df0b9d0ff1ac44d 100644 (file)
--- a/lib/MC/MCObjectStreamer.cpp
+++ b/lib/MC/MCObjectStreamer.cpp
@@ -99,9 +99,9 @@ void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
     EmitIntValue(AbsValue, Size, AddrSpace);
     return;
   }
-  DF->addFixup(MCFixup::Create(DF->getContents().size(),
-                               Value,
-                               MCFixup::getKindForSize(Size, false)));
+  DF->getFixups().push_back(
+      MCFixup::Create(DF->getContents().size(), Value,
+                      MCFixup::getKindForSize(Size, false)));
   DF->getContents().resize(DF->getContents().size() + Size, 0);
 }
 
@@ -204,7 +204,7 @@ void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst) {
   raw_svector_ostream VecOS(Code);
   getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, IF->getFixups());
   VecOS.flush();
-  IF->getCode().append(Code.begin(), Code.end());
+  IF->getContents().append(Code.begin(), Code.end());
 }
 
 void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
@@ -288,7 +288,8 @@ bool MCObjectStreamer::EmitValueToOffset(const MCExpr *Offset,
 void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
 
-  DF->addFixup(MCFixup::Create(DF->getContents().size(), Value, FK_GPRel_4));
+  DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(), 
+                                            Value, FK_GPRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
 
@@ -296,7 +297,8 @@ void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
 void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
 
-  DF->addFixup(MCFixup::Create(DF->getContents().size(), Value, FK_GPRel_4));
+  DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(), 
+                                            Value, FK_GPRel_4));
   DF->getContents().resize(DF->getContents().size() + 8, 0);
 }
 

diff --git a/lib/MC/MCPureStreamer.cpp b/lib/MC/MCPureStreamer.cpp
index fd9ccf745514a3c39b096b843c16fc1d88057698..1563bdd107fcaa814894e1db14a942e9b8781cdc 100644 (file)
--- a/lib/MC/MCPureStreamer.cpp
+++ b/lib/MC/MCPureStreamer.cpp
@@ -194,7 +194,7 @@ void MCPureStreamer::EmitInstToFragment(const MCInst &Inst) {
   getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
   VecOS.flush();
 
-  IF->getCode() = Code;
+  IF->getContents() = Code;
   IF->getFixups() = Fixups;
 }
 
@@ -210,7 +210,7 @@ void MCPureStreamer::EmitInstToData(const MCInst &Inst) {
   // Add the fixups and data.
   for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
     Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
-    DF->addFixup(Fixups[i]);
+    DF->getFixups().push_back(Fixups[i]);
   }
   DF->getContents().append(Code.begin(), Code.end());
 }

diff --git a/lib/MC/WinCOFFStreamer.cpp b/lib/MC/WinCOFFStreamer.cpp
index 8c8ae3f0b3c690d6fddcfaf06b4a7939df5d4752..359b388618e5262b43951ca0c86be0996840b3e7 100644 (file)
--- a/lib/MC/WinCOFFStreamer.cpp
+++ b/lib/MC/WinCOFFStreamer.cpp
@@ -288,9 +288,10 @@ void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol)
 {
   MCDataFragment *DF = getOrCreateDataFragment();
 
-  DF->addFixup(MCFixup::Create(DF->getContents().size(),
-                               MCSymbolRefExpr::Create (Symbol, getContext ()),
-                               FK_SecRel_4));
+  DF->getFixups().push_back(
+      MCFixup::Create(DF->getContents().size(),
+                      MCSymbolRefExpr::Create (Symbol, getContext ()),
+                      FK_SecRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
 
@@ -339,7 +340,7 @@ void WinCOFFStreamer::EmitInstruction(const MCInst &Instruction) {
   MCInstFragment *Fragment =
     new MCInstFragment(Instruction, getCurrentSectionData());
 
-  raw_svector_ostream VecOS(Fragment->getCode());
+  raw_svector_ostream VecOS(Fragment->getContents());
 
   getAssembler().getEmitter().EncodeInstruction(Instruction, VecOS,
                                                 Fragment->getFixups());