Refactor the machine code emitter interface to pull the pointers for the current

code emission location into the base class, instead of being in the derived classes.

This change means that low-level methods like emitByte/emitWord now are no longer
virtual (yaay for speed), and we now have a framework to support growable code
segments.  This implements feature request #1 of PR469.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28059 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 7 insertions, 145 deletions

diff --git a/lib/CodeGen/ELFWriter.cpp b/lib/CodeGen/ELFWriter.cpp
index a802c1aa79..c03b6272b5 100644
--- a/lib/CodeGen/ELFWriter.cpp
+++ b/lib/CodeGen/ELFWriter.cpp
@@ -56,24 +56,12 @@ namespace llvm {
     ELFCodeEmitter(ELFWriter &ew) : EW(ew), OutBuffer(0) {}
 
     void startFunction(MachineFunction &F);
-    void finishFunction(MachineFunction &F);
+    bool finishFunction(MachineFunction &F);
 
     void emitConstantPool(MachineConstantPool *MCP) {
       if (MCP->isEmpty()) return;
       assert(0 && "unimp");
     }
-    virtual void emitByte(unsigned char B) {
-      OutBuffer->push_back(B);
-    }
-    virtual void emitWord(unsigned W) {
-      assert(0 && "ni");
-    }
-    virtual uint64_t getCurrentPCValue() {
-      return OutBuffer->size();
-    }
-    virtual uint64_t getCurrentPCOffset() {
-      return OutBuffer->size()-FnStart;
-    }
     void addRelocation(const MachineRelocation &MR) {
       assert(0 && "relo not handled yet!");
     }
@@ -113,6 +101,10 @@ void ELFCodeEmitter::startFunction(MachineFunction &F) {
                       ELFWriter::ELFSection::SHF_EXECINSTR |
                       ELFWriter::ELFSection::SHF_ALLOC);
   OutBuffer = &ES->SectionData;
+  std::cerr << "FIXME: This code needs to be updated for changes in the"
+            << " CodeEmitter interfaces.  In particular, this should set "
+            << "BufferBegin/BufferEnd/CurBufferPtr, not deal with OutBuffer!";
+  abort();
 
   // Upgrade the section alignment if required.
   if (ES->Align < Align) ES->Align = Align;
@@ -127,7 +119,7 @@ void ELFCodeEmitter::startFunction(MachineFunction &F) {
 
 /// finishFunction - This callback is invoked after the function is completely
 /// finished.
-void ELFCodeEmitter::finishFunction(MachineFunction &F) {
+bool ELFCodeEmitter::finishFunction(MachineFunction &F) {
   // We now know the size of the function, add a symbol to represent it.
   ELFWriter::ELFSym FnSym(F.getFunction());
 
@@ -157,6 +149,7 @@ void ELFCodeEmitter::finishFunction(MachineFunction &F) {
 
   // Finally, add it to the symtab.
   EW.SymbolTable.push_back(FnSym);
+  return false;
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/CodeGen/MachineCodeEmitter.cpp b/lib/CodeGen/MachineCodeEmitter.cpp
deleted file mode 100644
index 301d9afb8a..0000000000
--- a/lib/CodeGen/MachineCodeEmitter.cpp
+++ /dev/null
@@ -1,131 +0,0 @@
-//===-- MachineCodeEmitter.cpp - Implement the MachineCodeEmitter itf -----===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the MachineCodeEmitter interface.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/MachineCodeEmitter.h"
-#include <fstream>
-#include <iostream>
-using namespace llvm;
-
-namespace {
-  class FilePrinterEmitter : public MachineCodeEmitter {
-    std::ofstream actual;
-    std::ostream &o;
-    MachineCodeEmitter &MCE;
-    unsigned counter;
-    unsigned values[4];
-
-  public:
-    FilePrinterEmitter(MachineCodeEmitter &M, std::ostream &os)
-      : o(os), MCE(M), counter(0) {
-      openActual();
-    }
-
-    ~FilePrinterEmitter() {
-      o << "\n";
-      actual.close();
-    }
-
-    void openActual() {
-      actual.open("lli.actual.obj");
-      if (!actual.good()) {
-        std::cerr << "Cannot open 'lli.actual.obj' for writing\n";
-        abort();
-      }
-    }
-
-    void startFunction(MachineFunction &F) {
-      // resolve any outstanding calls
-      MCE.startFunction(F);
-    }
-    void finishFunction(MachineFunction &F) {
-      MCE.finishFunction(F);
-    }
-
-    void emitConstantPool(MachineConstantPool *MCP) {
-      MCE.emitConstantPool(MCP);
-    }
-    void initJumpTableInfo(MachineJumpTableInfo *MJTI) {
-      MCE.initJumpTableInfo(MJTI);
-    }
-    void emitJumpTableInfo(MachineJumpTableInfo *MJTI,
-                           std::map<MachineBasicBlock*,uint64_t> &MBBM) {
-      MCE.emitJumpTableInfo(MJTI, MBBM);
-    }
-    
-    void startFunctionStub(unsigned StubSize) {
-      MCE.startFunctionStub(StubSize);
-    }
-
-    void *finishFunctionStub(const Function *F) {
-      return MCE.finishFunctionStub(F);
-    }
-
-    void emitByte(unsigned char B) {
-      MCE.emitByte(B);
-      actual << B; actual.flush();
-
-      values[counter] = (unsigned int) B;
-      if (++counter % 4 == 0 && counter != 0) {
-        o << std::hex;
-        for (unsigned i=0; i<4; ++i) {
-          if (values[i] < 16) o << "0";
-          o << values[i] << " ";
-        }
-
-        o << std::dec << "\t";
-        for (unsigned i=0; i<4; ++i) {
-          for (int j=7; j>=0; --j) {
-            o << ((values[i] >> j) & 1);
-          }
-          o << " ";
-        }
-
-        o << "\n";
-
-        unsigned instr = 0;
-        for (unsigned i=0; i<4; ++i)
-          instr |= values[i] << (i*8);
-
-        o << "--- * --- * --- * --- * ---\n";
-        counter %= 4;
-      }
-    }
-
-    void emitWord(unsigned W) {
-      MCE.emitWord(W);
-    }
-    uint64_t getConstantPoolEntryAddress(unsigned Num) {
-      return MCE.getConstantPoolEntryAddress(Num);
-    }
-    uint64_t getJumpTableEntryAddress(unsigned Num) {
-      return MCE.getJumpTableEntryAddress(Num);
-    }
-    virtual unsigned char* allocateGlobal(unsigned size, unsigned alignment)
-    { return MCE.allocateGlobal(size, alignment); }
-
-    uint64_t getCurrentPCValue() {
-      return MCE.getCurrentPCValue();
-    }
-    uint64_t getCurrentPCOffset() {
-      return MCE.getCurrentPCOffset();
-    }
-    void addRelocation(const MachineRelocation &MR) {
-      return MCE.addRelocation(MR);
-    }
-  };
-}
-
-MachineCodeEmitter *
-MachineCodeEmitter::createFilePrinterEmitter(MachineCodeEmitter &MCE) {
-  return new FilePrinterEmitter(MCE, std::cerr);
-}