Subzero: Add basic ELFObjectWriter (text section, symtab, strtab, headers)

src/assembler.cpp

 //===- subzero/src/assembler.cpp - Assembler base class -------------------===//
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Assembler class.
 //
 //===----------------------------------------------------------------------===//
 
 #include "assembler.h"
 #include "IceGlobalContext.h"
-#include "IceMemoryRegion.h"
 #include "IceOperand.h"
 
 namespace Ice {
 
 static uintptr_t NewContents(Assembler &assembler, intptr_t capacity) {
   uintptr_t result = assembler.AllocateBytes(capacity);
   return result;
 }
 
 #ifndef NDEBUG
@@ skipping 35 matching lines @@
   fixups_processed_ = false;
 #endif // !NDEBUG
 
   // Verify internal state.
   assert(Capacity() == kInitialBufferCapacity);
   assert(Size() == 0);
 }
 
 AssemblerBuffer::~AssemblerBuffer() {}
 
-void AssemblerBuffer::ProcessFixups(const MemoryRegion &region) {
-  for (SizeT I = 0; I < fixups_.size(); ++I) {
-    AssemblerFixup *fixup = fixups_[I];
-    fixup->Process(region, fixup->position());
-  }
-}
-
-void AssemblerBuffer::FinalizeInstructions(const MemoryRegion &instructions) {
-  // Copy the instructions from the buffer.
-  MemoryRegion from(reinterpret_cast<void *>(contents()), Size());
-  instructions.CopyFrom(0, from);
-
-  // Process fixups in the instructions.
-  ProcessFixups(instructions);
-#ifndef NDEBUG
-  fixups_processed_ = true;
-#endif // !NDEBUG
-}
-
 void AssemblerBuffer::ExtendCapacity() {
   intptr_t old_size = Size();
   intptr_t old_capacity = Capacity();
   const intptr_t OneMB = 1 << 20;
   intptr_t new_capacity = std::min(old_capacity * 2, old_capacity + OneMB);
   if (new_capacity < old_capacity) {
     // FATAL
     llvm_unreachable("Unexpected overflow in AssemblerBuffer::ExtendCapacity");
   }
 
   // Allocate the new data area and copy contents of the old one to it.
   uintptr_t new_contents = NewContents(assembler_, new_capacity);
   memmove(reinterpret_cast<void *>(new_contents),
           reinterpret_cast<void *>(contents_), old_size);
 
   // Compute the relocation delta and switch to the new contents area.
   intptr_t delta = new_contents - contents_;
   contents_ = new_contents;
 
   // Update the cursor and recompute the limit.
   cursor_ += delta;
   limit_ = ComputeLimit(new_contents, new_capacity);
 
   // Verify internal state.
   assert(Capacity() == new_capacity);
   assert(Size() == old_size);
 }
 
+llvm::StringRef Assembler::getBufferView() const {
+  return llvm::StringRef(reinterpret_cast<const char *>(buffer_.contents()),
+                         buffer_.Size());
+}
+
 void Assembler::emitIASBytes(GlobalContext *Ctx) const {
   Ostream &Str = Ctx->getStrEmit();
   intptr_t EndPosition = buffer_.Size();
   intptr_t CurPosition = 0;
   const intptr_t FixupSize = 4;
   for (AssemblerBuffer::FixupList::const_iterator
            FixupI = buffer_.fixups_begin(),
            FixupE = buffer_.fixups_end(); FixupI != FixupE; ++FixupI) {
     AssemblerFixup *NextFixup = *FixupI;
     intptr_t NextFixupLoc = NextFixup->position();
@@ skipping 20 matching lines @@
   }
   // Handle any bytes that are not prefixed by a fixup.
   for (intptr_t i = CurPosition; i < EndPosition; ++i) {
     Str << "\t.byte 0x";
     Str.write_hex(buffer_.Load<uint8_t>(i));
     Str << "\n";
   }
 }
 
 } // end of namespace Ice